Hinge structure comprising elastic member, and foldable electronic device comprising same

Abstract

The present disclosure relates to a foldable electronic device. The foldable electronic device according to one embodiment of the present disclosure comprises a hinge structure, wherein the hinge structure comprises: a cam member including first to fourth fixing cam portions facing first to fourth cams coupled to first to fourth shafts; first and second elastic members coupled to the first and second shafts so as to provide a first elastic force to the first and second cams; and third and fourth elastic members coupled to the third and fourth shafts so as to provide a second elastic force to the third and fourth cams, and is formed such that the slope of the first cam is different from the slope of the third cam and the type of the first elastic member is different from the type of the third elastic member.

Description

Hinge structure including elastic member and foldable electronic device including same Various embodiments of the present document relate to hinge structures including elastic members. Portable electronic devices such as smartphones can support calling functions and various content search and provision functions based on various types of applications. The portable electronic device can output a screen corresponding to each function in the process of providing various functions. When using the various functions described above, the user may want to use a wider screen. In general portable electronic devices, if the display device is expanded for screen display, the overall size increases, which may reduce portability. Accordingly, foldable electronic devices are provided so that the screen size can be increased while maintaining portability. Foldable electronic devices can have folded and unfolded states.

[0001] According to various embodiments of the present disclosure, a foldable electronic device (or a portable electronic device, a portable communication device, a foldable electronic device, or a foldable electronic device having a communication function, a foldable portable electronic device) includes a hinge structure, wherein the hinge structure comprises a first rotating member that rotates around a first axis and a second rotating member that rotates around a second axis, a first arm member that rotates around a third axis while rotating in response to the rotation of the first rotating member, and a second arm member that rotates around a fourth axis while rotating in response to the rotation of the second rotating member, a first shaft on which a first main gear is arranged and connected to the first arm member, a second shaft on which a second main gear is arranged and connected to the second arm member, a third shaft on which a first gear is arranged between the first main gear and the second main gear, a fourth shaft on which a second gear is arranged between the third shaft and the second main gear, and the second gear, first to fourth cams coupled to each of the first to fourth shafts, and a second cam coupled to each of the first to fourth shafts. A cam member including first to fourth fixed cam portions that are coupled and face the first to fourth cams, a first elastic member coupled to the first shaft and providing an elastic force of a first magnitude to the first cam, a second elastic member coupled to the second shaft and providing an elastic force of a first magnitude to the second cam, a third elastic member coupled to the third shaft and providing an elastic force of a second magnitude different from the first magnitude to the third cam, and a fourth elastic member coupled to the fourth shaft and providing an elastic force of the second magnitude to the fourth cam, wherein an inclination of a mountain of the first cam is different from an inclination of a mountain of the third cam, and a type of the first elastic member may be formed differently from a type of the third elastic member. In addition, this disclosure presents various embodiments. FIG. 1 is a drawing showing an example of an appearance of a folded state of a foldable electronic device according to one embodiment. FIG. 2 is an exploded perspective view of a foldable electronic device according to one embodiment. FIG. 3 is a drawing showing an example of an exploded perspective view of a hinge structure according to one embodiment, viewed from a first direction. FIG. 4 is a drawing showing an example of an exploded perspective view of a hinge structure according to one embodiment, viewed from a second direction. FIG. 5 is a drawing showing an example of a first direction in which each component of a hinge structure is combined according to one embodiment. FIG. 6 is a drawing showing an example of a second direction in which each component of a hinge structure is coupled according to one embodiment. FIG. 7 is a drawing showing one example of a type of cam member and cams in a hinge structure according to one embodiment. FIG. 8 is a drawing showing torque changes during the unfolding and folding operations of a hinge structure according to one embodiment. FIG. 9 is a drawing showing another example of a cam member and cams in a hinge structure according to one embodiment. Fig. 10 is a drawing showing the change in torque during the unfolding and folding operation of the hinge structure exemplified in Fig. 9. FIG. 11 is a drawing showing an example of a hinge structure in which the positions of the cam member and the cams are changed according to one embodiment. FIG. 12 is a drawing showing an example of a hinge structure in which the positions of cams are changed according to one embodiment. FIG. 13 is a drawing showing an example of a cam pattern according to one embodiment. FIG. 14 is a block diagram of an electronic device within a network environment according to various embodiments. Below, various embodiments of this document are described with reference to the attached drawings. Hereinafter, various embodiments of the present document provide a hinge structure and a foldable electronic device including the same, which can provide a frictional force (or torque) required for a hinge operation of a foldable electronic device of a certain size or larger by applying different types of elastic members, and additionally or alternatively more firmly support an unfolding operation or a folding operation, or a flex operation (an operation that supports a foldable electronic device so that it can be temporarily fixed at a certain mounting angle (e.g., an angle greater than 0 degrees and less than 180 degrees)) of the foldable electronic device. According to various embodiments of the present invention, the hinge structure and the foldable electronic device can provide sufficient hinge performance even for large electronic devices with increasing weight and size. For example, the hinge structure and the foldable electronic device of the present invention can provide improved device housing control functions by providing sufficient torque and consistent detent forces while opening and closing the electronic device. Other intended purposes according to the embodiments of the present disclosure will be mentioned as needed in the process of explaining each embodiment. In addition, various purposes and effects provided by the foldable electronic device including the hinge structure according to various embodiments can be mentioned according to the embodiments of the detailed description. FIG. 1 is a drawing showing an example of an appearance of a folded state of a foldable electronic device according to one embodiment. FIG. 2 is an exploded perspective view of a foldable electronic device according to one embodiment. Referring to FIGS. 1 and 2, a foldable electronic device (100) (or optionally an electronic device, a portable electronic device, a portable communication device, a foldable electronic device, a portable device, a foldable portable electronic device) according to an embodiment includes a first housing (110), a second housing (120), a hinge housing (150), wing plates (131, 132) (or optionally plates), a display (160) (or optionally a flexible display), and at least one hinge structure (200a, 200b, 200c) (or optionally a hinge structure, a hinge assembly, a gear assembly). In the foldable electronic device (100), the wing plates (131, 132) may be removed or may be attached to or integrated with another structure (e.g., the display (160)). Additionally or alternatively, the foldable electronic device (100) may further include an auxiliary display (160a) and a camera (cam), and may further include structures related to user functions of the foldable electronic device (100), such as a speaker hole and a connector hole, arranged on one side of the housing. According to one embodiment, when the foldable electronic device (100) is in a folded state, at least a part of the folding area of ​​the display (160) forms a water drop shape (or a water drop shape or dumbbell shape that is convex in the rearward direction when viewed from the front to the rearward direction of the display (e.g., when viewed from the z-axis to the -z-axis direction), a rearward convex shape), thereby securing a folding R (curvature) that prevents cracks or buckling from occurring in the folding area of ​​the display (160). In addition, the foldable electronic device (100) can arrange the folding area of ​​the dumbbell-shaped display (160) within a predetermined space of the housings (110, 120), thereby maintaining the arrangement gap between the housings (110, 120) to be equal to or less than a reference value or in an 11-shape when the foldable electronic device (100) is in a folded state. The foldable electronic device (100) having the above-described structure provides at least one support structure in at least some of the housings (110, 120) and the hinge housing (150), thereby preventing the hinge housing (150) from moving inwardly of the housings (110, 120) when an external impact is applied to the foldable electronic device (100), thereby preventing or reducing damage to the internal structure of the foldable electronic device (100). According to one embodiment, the first housing (110) may be connected to the second housing (120) using at least one hinge structure (200a, 200b, 200c). The first housing (110) may include a first bottom area (110_bot) on which the display (160) is mounted, and side walls (e.g., 110a, 110b, 110c) or a separately provided frame that are arranged at an edge of the first bottom area (110_bot) and surround a frame of the display (160) or an edge of the area on which the display (160) is mounted. For example, the first housing (110) may include a first side wall (110a) arranged in a direction perpendicular to the longitudinal direction of the first side portion (110d) at both edges of the first side portion (110d) facing the second housing (120), a second side wall (110b) extending from one end of the first side wall (110a) and arranged parallel to the first side portion (110d), and a third side wall (110c) arranged parallel to the first side wall (110a) at one end of the second side wall (110b). The first to third side walls (110a, 110b, 110c) may be formed to protrude upward (e.g., in the z-axis direction) from the bottom surface of the first bottom region (110_bot) by a pre-designed height. At least a portion of the first side (110d) may have a predetermined curvature and an engraved shape downward (e.g., in the -z-axis direction) from the bottom surface of the first bottom region (110_bot) so that at least a portion of the hinge housing (150) may be placed. Additionally, a rear cover may be arranged on the back surface of the first housing (110). Here, the rear cover may be omitted. At least a portion of the first housing (110) may be adhered to the first region (161) of the display (160). Alternatively, a portion of an edge of the front surface of the first housing (110) may be adhered to at least a portion of an edge of the first region (161) of the display (160).In this regard, an adhesive layer may be placed between the front surface of the first housing (110) and the first area (161) of the display (160). According to one embodiment, the first housing (110) may be provided with at least a portion of the inner side having a hollow shape (or an empty shape). At least one of at least one circuit board, at least one battery, and at least a portion of at least one camera module may be arranged inside the first housing (110). The circuit board and the battery arranged inside the first housing (110) may be electrically connected to at least one circuit board and at least one battery arranged inside the second housing (120) through a flexible substrate (not shown). For example, the flexible substrate (not shown) may extend from a portion of the first housing (110) across the hinge housing (150) to a portion of the second housing (120). A portion of the flexible substrate (not shown) may be located inside the hinge housing (150). For example, a processor and a memory may be arranged on the circuit board arranged in the first housing (110). According to one embodiment, the first housing (110) may be formed of at least a portion of a metal material, or at least a portion of a non-metal material. The first housing (110) may be formed of a material having a certain amount of rigidity so as to support at least a portion of the display (160). In one embodiment, when the foldable electronic device (100) is in an unfolded state, at least a portion of a first side portion (110d) of the first housing (110) facing the second housing (120) may include a recessed portion in which at least a portion is recessed so that a hinge housing (150) can be placed. According to one embodiment, the first housing (110) is connected to at least one hinge structure (200a, 200b, 200c) and can perform a clockwise or counterclockwise rotational movement from any point between the -x-axis and the x-axis to any point between the z-axis and the -z-axis by an external pressure applied from the outside. When the foldable electronic device (100) is in a folded state, the first housing (110) can be arranged parallel to the z-axis or arranged parallel to the second housing (120). While the first housing (110) is arranged parallel to the second housing (120) (or when the foldable electronic device (100) is in a folded state), three side walls (or borders, or edges) of the first housing (110) (e.g., at least a portion of the borders adjacent to the second housing (120) when the foldable electronic device is in an unfolded state) may be arranged to contact, face, or be adjacent to three side walls of the second housing (120) (or the remaining borders excluding the second side adjacent to the first side of the first housing (110) when the foldable electronic device (100) is in an unfolded state). According to one embodiment, the second housing (120) may be connected (or fastened, coupled) to the first housing (110) via at least one hinge structure (200a, 200b, 200c). The second housing (120) may include a front surface on which at least a portion of the display (160) (e.g., the second region (162)) is mounted, a frame surrounding a border of the front surface or at least a portion of the second region (162) of the display (160). At least a portion of the second housing (120) may be adhered to the second region (162) of the display (160). Alternatively, a portion of an edge of the front surface of the second housing (120) may be adhered to an edge of the second region (162) of the display (160). In this regard, an adhesive layer may be disposed between the front surface of the second housing (120) and the second region (162) of the display (160). According to one embodiment, the second housing (120) may have a hollow formed in at least a portion of the inner side, similar to the first housing (110). At least one circuit board and at least one battery may be arranged inside the second housing (120). Alternatively, the at least one battery may be arranged in either one of the first housing (110) and the second housing (120), or in both. At least one of the printed circuit board or the battery arranged in the second housing (120) may be electrically connected to a component (e.g., at least one of the printed circuit board or the battery) arranged in the first housing (110) via a flexible substrate. According to one embodiment, the second housing (120) may be formed of at least a portion of a metal material similar to the first housing (110), or may be provided of at least a portion of a non-metal material. The second housing (120) may be formed of a material having a certain amount of rigidity so as to support at least a portion of the display (160). The sidewall structure of the second housing (120) may be formed to correspond to the sidewall structure of the first housing (110). In one embodiment, when the foldable electronic device (100) is in an unfolded state, the second housing (120) may include a second side portion facing the first housing (110) (or a portion adjacent to the first housing (110)), and fourth to sixth sidewalls surrounding the second side portion. The second side portion may include a recessed portion (e.g., a recessed portion) at least partially recessed so that the hinge housing (150) may be placed. The sunken portion of the second housing (120) may be positioned adjacent to the sunken portion of the first housing (110). A rear cover may be positioned on the rear of the second housing (120). Here, the rear cover may be omitted. According to one embodiment, at least a portion of the display (160) may have flexibility. For example, the display (160) may include a first region (161) at least a portion of which is disposed on the first housing (110), a second region (162) at least a portion of which is disposed on the second housing (120), and a third region (163) (or a folding region, or a folding region) positioned between the first region (161) and the second region (162). As an example, when the foldable electronic device (100) is in a folded or unfolded state, at least a portion of the first region (161) and the second region (162) may be disposed in a flat state, and at least a portion of the third region (163) may have a curved state when the foldable electronic device (100) is in a folded state. For example, the first region (161) and the second region (162) can maintain a flat state regardless of the state of the foldable electronic device (100) (the arrangement position of the flat surface is changed), and the third region (163) can be transformed into a curved state or a flat state corresponding to the state of the foldable electronic device (100). For example, the third region (163) can have a flat state (or a flat state) when the foldable electronic device (100) is in an unfolded state, and can have at least a portion of a curved state (or a curved state) when the foldable electronic device (100) is in a folded state. According to one embodiment, the display (160) may include at least some of various layers. For example, the display (160) may include at least some of an outer protective layer (or a glass layer, or a polymer layer) having a certain amount of transparency and a specified size, a display panel layer disposed under the outer protective layer to display a screen, and at least one first back layer disposed under the display panel layer, regardless of the order. The first back layer (or back panel, back portion) may include at least one layer (or a layer excluding at least one of the above-described layers) of a shock absorbing layer (or an embossing layer), a heat dissipation layer (or a metal sheet layer, a metal layer, a conductive sheet). Additionally or alternatively, the first back layer may further include an electromagnetic induction panel (e.g., a digitizer). The display (160) may further include a second back layer disposed under the first back layer. The second back layer (or back panel, back portion) may include at least one metal layer (or a metal sheet) at least partially formed of a metal material. At least a portion of the second back layer may include a designated pattern (e.g., a lattice pattern, a slit pattern) so as to be bendable. Alternatively, at least a portion of the second back layer may be formed of another bendable material (e.g., a polymer material, rubber, leather material). At least one of the first back layer and the second back layer may be omitted. At least one hinge structure (200a, 200b, 200c) may be disposed at least partially in the hinge housing (150), and at least some of the plurality of hinge structures (200a, 200b, 200c) may have similar structures and shapes to each other. Alternatively, at least some of the plurality of hinge structures (200a, 200b, 200c) may have different structures and shapes from the remaining hinge structures. Alternatively, all three hinge structures (200a, 200b, 200c) may have the same or similar structures and may be disposed in different directions. Meanwhile, in the illustrated drawing, a form in which three hinge structures (200a, 200b, 200c) are disposed is exemplified, and the foldable electronic device (100) may have two hinge structures or four or more hinge structures disposed. The wing plates (131, 132) are placed on at least one hinge structure (200a, 200b, 200c) or combined with at least one hinge structure (200a, 200b, 200c) so as to cover a surface in the z-axis direction of at least one hinge structure (200a, 200b, 200c) when the foldable electronic device (100) is in an unfolded state. The wing plates (131, 132) may be provided in a form separate from the housings (110, 120). Accordingly, a gap may be formed between the wing plates (131, 132) and the housings (110, 120). The wing plates (131, 132) may be arranged to correspond to at least a portion of a lower surface (e.g., a surface in the -z-axis direction) of a third region (163) of the display (160). The wing plates (131, 132) rotate clockwise or counterclockwise according to a hinge operation of at least one hinge structure (200a, 200b, 200c). For example, while the first wing plate (131) rotates counterclockwise, the second wing plate (132) may rotate clockwise, and while the first wing plate (131) rotates clockwise, the second wing plate (132) may rotate counterclockwise. The first wing plate (131) can support a flat first surface of a third region (163) of a display (160) that folds into a dumbbell shape, and the second wing plate (132) can support a flat second surface (a surface symmetrical to the first surface with respect to the z-axis) of the third region (163) of a display (160) that folds into a dumbbell shape. The foldable electronic device (100) described above can provide a torque (or frictional force) required during a folding or unfolding operation of the foldable electronic device (100) by having at least one hinge structure among the plurality of hinge structures (200a, 200b, 200c) include elastic members of different types. Additionally or alternatively, the cam structures (e.g., the cam member and the cams) of at least one hinge structure among the plurality of hinge structures (200a, 200b, 200c) are arranged in different shapes, thereby supporting a stable and sturdy operation change or support operation while supporting at least one operation of the foldable electronic device (100) from a folding state to an unfolded state, from an unfolded state to a folded state, or a flex operation. FIG. 3 is a drawing showing an example of an exploded perspective view of a hinge structure according to one embodiment when viewed from a first direction. FIG. 4 is a drawing showing an example of an exploded perspective view of a hinge structure according to one embodiment when viewed from a second direction. FIG. 5 is a drawing showing an example of a first direction in which each component of a hinge structure according to one embodiment is combined. FIG. 6 is a drawing showing an example of a second direction in which each component of a hinge structure according to one embodiment is combined. The hinge structure 201 illustrated in FIGS. 3 to 6 may correspond to at least one of the plurality of hinge structures (200a, 200b, 200c) described above in FIG. 2. Alternatively, at least some of the arrangement of elastic members and cam shapes of the hinge structure 201 described below may be applied to at least one of the plurality of hinge structures (200a, 200b, 200c). Referring to FIGS. 1 to 4, the hinge structure (201) (or gear assembly) may include a fixed bracket (213) (or a support bracket, a support member), a first rotation member (211) (or a first rotation bracket), a second rotation member (212) (or a second rotation bracket), a first arm member (221) (or a first arm, a second arm structure), a second arm member (222) (or a second arm, a second arm structure), a first link member (215), a second link member (216), a third link member (223), and a fourth link member (224). According to one embodiment, referring to FIG. 5, the hinge structure (201) can be divided into a configuration including a torque structure (230_tr) (e.g., an elastic force providing structure (242), a cam coupling structure (244), a first surface pressure structure (249_1), a second surface pressure structure (249_2)) that provides frictional force during an unfolding or folding operation during the rotation process of the hinge structure (201) and a gear linkage structure (220_ge). As an example, the elastic force providing structure (242) may include a first cam elastic member (242a) (or a first elastic member, a first elastic body) of a first type and a second cam elastic member (242b) (or a second elastic member, a second elastic body), a third cam elastic member (242c) (or a third elastic member, a third elastic body) of a second type different from the first type, and a fourth cam elastic member (242d) (or a fourth elastic member, a fourth elastic body). The above cam coupling structure (244) (or cam structure) may include a cam member (241) in which a plurality of fixed cam parts (241a, 241b, 241c, 241d) are arranged, and a plurality of cams (244a, 244b, 244c, 244d) that are cam-coupled with the fixed cam parts (241a, 241b, 241c, 241d) of the cam member (241). The first surface pressure structure (249_1) may include a first friction member (249a1) and a third friction member (249b1) that are arranged between one side of the first support member (248a), one side of the second support member (248b), and the support members (248a, 248b). The above second surface pressure structure (249_2) may include a second friction member (249a2) and a fourth friction member (249b2) arranged between the other side of the first support member (248a) and the other side of the second support member (248b) and the support members (248a, 248b). Additionally, referring to FIG. 6, the hinge structure (201) can perform hinge operation based on various axes. For example, the hinge structure (201) includes a first axis (axis_A1) that becomes the center of rotation of the first rotation member (211) inserted into the fixed bracket (213), a second axis (axis_A2) that becomes the center of rotation of the first rotation member (211) inserted into the fixed bracket (213), a third axis (axis_B3) that becomes the center of rotation of the first shaft (231) connected to the first arm member (221), a fourth axis (axis_B4) that becomes the center of rotation of the second shaft (232) connected to the second arm member (222), a fifth axis (axis_A3) that becomes the center of rotation of the edge portion of the first rotation member (211) connected to the first link member (215), a sixth axis (axis_A4) that becomes the center of rotation of the edge portion of the second rotation member (212) connected to the second link member (216), and a first arm connected to the third link member (223). It may include a seventh axis (axis_B1) that becomes the center of rotation of the member (221), an eighth axis (axis_B2) that becomes the center of rotation of the second arm member (222) coupled to the fourth link member (224), a ninth axis (axis_B5) that corresponds to the center of rotation of the first gear shaft (238) on which the first gear (238a) (or the first linkage gear, the first idle gear) is arranged, and a tenth axis (axis_B6) that corresponds to the center of rotation of the second gear shaft (239) on which the second gear (239a) (or the second linkage gear, the second idle gear) is arranged. Meanwhile, at least a part of the configuration of the hinge structure (201) described above (e.g., at least a part of the first to fourth link members (215, 216, 223, 224)) may be omitted. For example, the first rotation member (211) and the second rotation member (212) may be directly coupled to the housings (110, 120 of FIG. 2), and the arm members (221, 222) may be coupled to the rotation members (211, 212) and rotate in response to the rotation of the rotation members (211, 212). According to one embodiment, at least a part of the first to fourth link members (215, 216, 223, 224) may be integrated. For example, the first link member (215) and the third link member (223) may be integrated, and the second link member (216) and the fourth link member (224) may be integrated. Alternatively, at least some of the first to fourth link members (215, 216, 223, 224) may be integrated into the housing. A hinge structure (201) according to one embodiment of the present disclosure includes a first main gear (221_2) (or optionally a first gear, or a first shaft gear) formed (or arranged) on the first arm member (221), a second main gear (222_2) (or optionally a second gear, or a second shaft gear) formed (or arranged) on the second arm member (222), and at least one interlocking gear (238a, 239a) (or optionally idle gears, auxiliary gears) arranged between the first main gear (221_2) and the second main gear (222_2). The at least one interlocking gear (238a, 239a) may be arranged on gear shafts (238, 239) (or shafts), respectively. For example, the first gear (238a) may be arranged (or formed) on the first gear shaft (238) (or the first gear shaft, the first linkage shaft, the first gear shaft, the first auxiliary shaft, the third shaft). The second gear (239a) may be arranged (or formed) on the second gear shaft (239) (or the second gear shaft, the second gear shaft, the second auxiliary shaft, the fourth shaft). In the embodiments of the present document, the gear shaft may refer to a rod-shaped portion on which a gear body including gear teeth is arranged. In addition, the shaft may refer to a shape portion that protrudes along the rotation axis of the gear from the gear body portion. Hereinafter, each component of the hinge structure (201) will be described with reference to FIGS. 1 to 6.A hinge structure (201) according to one embodiment is used to fix the first main gear (221_2) and the second main gear (222_2), at least one linkage gear (238a, 239a), and includes a gear bracket (236) (or stopper, arm support structure, shaft support structure, gear frame, gear support member, support member) that prevents the first arm member (221) and the second arm member (222) from rotating more than a specified angle, a shaft fixing part (243) used to fix the first shaft (231) and the second shaft (232), a cam member (241) on which a plurality of fixed cam parts (241a, 241b, 241c, 241d) are arranged, a plurality of cams (244a, 244b) that are cam-coupled with the fixed cam parts (241a, 241b, 241c, 241d) of the cam member (241). 244b, 244c, 244d), a first cam elastic member (242a) (or a first elastic member, a first elastic body, a first cam elastic body) and a second cam elastic member (242b) (or a second elastic member, a second elastic body, a second cam elastic body), a third cam elastic member (242c) (or a third elastic member, a third elastic body, a third cam elastic body), a fourth cam elastic member (242d) (or a fourth elastic member, a fourth elastic body, a fourth cam elastic body), a plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4), a plurality of friction members (249a1, It may include support members (248a, 248b, 248c) supporting a plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) with at least one surface facing each other, and fixing nuts (249d1, 249d2) (or fixing members, fixing bodies).According to one embodiment, the gear bracket (236) may include a fixing structure that fixes at least one of the first shaft (231), the second shaft (232), the first gear shaft (238), and the second gear shaft (239). According to one embodiment, the fixed bracket (213) may include, for example, an upper fixed bracket (213a) and a lower fixed bracket (213b). The upper fixed bracket (213a) and the lower fixed bracket (213b) may be joined by joining members (213c1, 213c2, 213c3) (e.g., joining screws). The upper fixed bracket (213a) and the lower fixed bracket (213b) may be formed of the same material (e.g., metal). At least a portion of an upper surface (e.g., a surface in the z-axis direction) of the upper fixed bracket (213a) may be provided in a flat shape. According to one embodiment, the upper fixed bracket (213a) may include at least a portion of a cross-section having an arc shape (or a curved surface) in a direction from the upper surface (e.g., a surface in the z-axis direction) to the lower surface (e.g., a surface in the -z-axis direction). The upper fixed bracket (213a) may include a fixed bracket upper portion (213a3), a fixed bracket lower portion (213a4), a first rail (213a1) (or a first rail structure inserted into a protruding rail), a second rail (213a2) (or a second rail structure inserted into a protruding rail), and a fixed bracket extension portion (213a5). The upper part (213a3) of the fixed bracket may have at least a portion of its upper surface formed flat and may include at least one hole or groove capable of being fastened with the lower fixed bracket (213b). The upper part (213a3) of the fixed bracket may form one side wall of the first rail (213a1) and the second rail (213a2). As an example, the upper part (213a3) of the fixed bracket may have portions of rails fastened with the rail structures of the first rotation member (211) and the second rotation member (212) respectively arranged on one side wall (e.g., one side wall facing the y-axis direction). At least a portion of the upper part (213a3) of the fixed bracket may be formed to cover at least a portion of the upper portions of the first rail (213a1) and the second rail (213a2). At least a portion of the upper portion (213a3) of the above fixed bracket can prevent the first rotation member (211) and the second rotation member (212) coupled to the first rail (213a1) and the second rail (213a2) from being separated from the first rail (213a1) and the second rail (213a2). The lower part (213a4) of the fixed bracket is positioned at a position spaced apart from the upper part (213a3) of the fixed bracket by a certain distance (e.g., the width (e.g., the length of the y-axis) of the first rotation member (211) or the second rotation member (212), and can be connected to the upper part (213a3) of the fixed bracket through the first rail (213a1) and the second rail (213a2). The upper surface (e.g., the surface facing the z-axis) of the lower part (213a4) of the fixed bracket can be formed flat. One side wall (e.g., the side wall facing the -y-axis) of the lower part (213a4) of the fixed bracket is positioned to face the upper part (213a3) of the fixed bracket, and can support one side of the first rotation member (211) and the second rotation member (212) inserted into the first rail (213a1) and the second rail (213a2). The fixed bracket On one side wall of the lower part (213a4), portions of rails (213a1, 213a2) that are connected to the rail structures of the first rotation member (211) and the second rotation member (212) can be arranged. The lower part (213a4) of the fixed bracket can have grooves (or holes) formed on the other side wall (e.g., a side wall facing the y-axis direction) into which shafts (e.g., a first shaft (231), a second shaft (232), a first gear shaft (238), a second gear shaft (239)) can be inserted. The above-described fixed bracket extension (213a5) may be positioned to protrude from one end of the lower end (213a4) of the fixed bracket (e.g., from the edge of the lower end (213a4) of the fixed bracket in the y-axis direction). The above-described fixed bracket extension (213a5) may be formed to be thinner than the thickness of the lower end (213a4) of the fixed bracket, and may be formed to have a length in the x-axis direction shorter than a length in the y-axis direction. The above fixed bracket extension (213a5) can be arranged to cover at least a portion of the shafts (231, 232, 238, 239), at least a portion of the first main gear (221_2), the second main gear (222_2), the first gear (238a), the second gear (239a), the support members (218a, 218b, 218c) and the plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4), the cam member (241), the cams (244a, 244b, 244c, 244d), the cam elastic members (242a, 242b, 242c, 242d), and at least a portion of the shaft fixing portion (243). The above-described fixed bracket extension (213a5) can prevent the detachment of the above-described configurations (e.g., at least a part of the shafts (231, 232, 238, 239), the first main gear (221_2), the second main gear (222_2), the first gear (238a), at least a part of the second gear (239a), the support members (218a, 218b, 218c) and the plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4), the cam member (241), the cams (244a, 244b, 244c, 244d), the cam elastic members (242a, 242b, 242c, 242d). The above fixed bracket extension (213a5) may include at least one coupling hole capable of coupling with at least one of the cam member (241) and the shaft fixing member (243). The first rail (213a1) and the second rail (213a2) may be arranged between the upper part (213a3) of the fixed bracket and the lower part (213a4) of the fixed bracket. According to one embodiment, a part of the first rail (213a1) may be arranged on a side wall of the upper part (213a3) of the fixed bracket, and another part of the first rail (213a1) may be arranged on a side wall of the lower part (213a4) of the fixed bracket. A bottom surface of the first rail (213a1) may include a curved surface similar to a shape of a part of a surface facing the -z-axis direction of the first rotation member (211). A part of the second rail (213a2) may be arranged on a side wall of the upper part (213a3) of the fixed bracket, and another part of the second rail (213a2) may be arranged on a side wall of the lower part (213a4) of the fixed bracket. The bottom surface of the second rail (213a2) may include a curved surface similar to a portion of a surface facing the -z-axis direction of the first rotation member (211). At least a portion of the second rail (213a2) may be connected to the first rail (213a1). Referring to FIG. 6, the first rail (213a1) may support the inserted first rotation member (211) to rotate along a first axis (axis_A1) (or a virtual first axis that becomes the center of the sliding motion along the rail). The second rail (213a2) may support the inserted second rotation member (212) to rotate along a second axis (axis_A2) (or a virtual second axis that becomes the center of the sliding motion along the rail). According to one embodiment, the first axis (axis_A1) and the second axis (axis_A2) may be formed to be spaced apart from each other by a specified interval. The above first axis (axis_A1) and second axis (axis_A2) may be formed above (air) the upper surface (e.g., surface in the z-axis direction) of the fixed bracket (213).Alternatively, the first axis (axis_A1) and the second axis (axis_A2) may be formed between the upper surface of the display (160 of FIG. 2) and the lower surface (e.g., the surface in the -z-axis direction) of the fixed bracket body (213a). As an example, the first axis (axis_A1) and the second axis (axis_A2) may be formed in the air above the upper surface (e.g., the surface in the -z-axis direction) of the fixed bracket body (213a). According to an embodiment, the distance between the first axis (axis_A1) and the second axis (axis_A2) may be formed differently from the distance between the third axis (axis_B3) formed by the first shaft (231) (or the axis passing through the center of the first shaft (231)) and the fourth axis (axis_B4) formed by the second shaft (232) (or the axis passing through the center of the second shaft (232). As an example, the gap between the first axis (axis_A1) and the second axis (axis_A2) may be formed smaller than the gap between the third axis (axis_B3) and the fourth axis (axis_B4). According to an embodiment, the first axis (axis_A1) and the second axis (axis_A2) may be formed higher than the third axis (axis_B3) and the fourth axis (axis_B4) with respect to the z-axis. Alternatively, the first axis (axis_A1) and the second axis (axis_A2) may be formed closer to the upper surface of the display (160 of FIG. 2) with respect to the z-axis than the third axis (axis_B3) and the fourth axis (axis_B4). At least a portion of the shape of the lower surface (e.g., the surface facing the -z-axis direction) of the lower fixed bracket (213b) may include a curved surface. At least a portion of the shape of the upper surface (e.g., the surface facing the z-axis direction) of the lower fixed bracket (213b) may be provided as a concave shape (or a convex shape in the -z-axis direction). For example, at least a portion of the lower surface of the lower fixed bracket (213b) may be formed to correspond to the inner shape of the hinge housing (150 of FIG. 2). The lower fixed bracket (213b) may be fastened to the upper fixed bracket (213a) through the connecting members (213c1, 213c2, 213c3). The lower fixed bracket (213b) may support one side of the first rotating member (211) and the second rotating member (212) connected to the upper fixed bracket (213a). At least one groove or hole may be formed in at least a portion of the lower fixing bracket (213b) to be coupled, fastened, or aligned with the upper fixing bracket (213a), and the upper fixing bracket (213a) may include at least one groove or at least one protruding structure inserted into the groove formed in the lower fixing bracket (213b). As an example, the length of the lower fixing bracket (213b) in the y-axis direction may have a similar length to the length of the upper fixing bracket top (213a3), the first rail (213a1) and the second rail (213a2), and the lower fixing bracket bottom (213a4) among the configurations of the upper fixing bracket (213a). According to one embodiment, the first rotational member (211) may be fastened to one side of the fixed bracket (213) (e.g., the first rail (213a1)) so as to enable a hinge movement. In this regard, the first rotational member (211) may include a first upper rotational body (211_1), a first lower rotational body (211_2), and a first rotational elastic body (211_3) (or an elastic body or elastic member of the first rotational member (211)). The first upper rotation body (211_1) may have a first upper rail structure (211_1a) formed on one side (e.g., the -x-axis edge) and a first upper link connection part (211_1b) formed on the other side (e.g., the x-axis edge). The first lower rotation body (211_2) may have a first lower rail structure (211_2a) formed on one side (e.g., the -x-axis edge) and a first lower link connection part (211_2b) formed on the other side (e.g., the x-axis edge). The first rotation elastic body (211_3) may be arranged between the first upper rotation body (211_1) and the first lower rotation body (211_2) to exert elastic force to push the first upper rotation body (211_1) and the first lower rotation body (211_2) in the -y-axis or y-axis direction, respectively. By this structure, the first upper rotation body (211_1) and the first lower rotation body (211_2) can be more firmly connected to the first rail (213a1) of the upper fixed bracket (213a), and cannot be easily separated from the first rail (213a1) during the rotation process. The first upper rail structure (211_1a) and the first lower rail structure (211_2a) may be arranged at symmetrical positions with the first rotational elastic body (211_3) therebetween. The side of the first upper rail structure (211_1a) may be coupled with, for example, one side of the first rail (213a1) (for example, a part of the first rail (213a1) arranged on the upper side (213a3) of the fixed bracket), and the side of the first lower rail structure (211_2a) may be coupled with, for example, the other side of the first rail (213a1) (for example, another part of the first rail (213a1) arranged on the lower side (213a4) of the fixed bracket). The bottom surfaces of the first upper rail structure (211_1a) and the first lower rail structure (211_2a) may be arranged to face the bottom surface of the first rail (213a1). The first upper link connecting portion (211_1b) may include a hole penetrating from the -y-axis in the y-axis direction, and the second upper link connecting portion (212_1b) may include a hole penetrating from the -y-axis in the y-axis direction and aligned to be connected to the hole formed in the first upper link connecting portion (211_1b) in the y-axis direction. The first upper link connecting portion (211_1b) and the first lower link connecting portion (211_2b) may be mounted or fastened to the first link member (215). In this process, the holes formed in the first upper link connecting portion (211_1b) and the second upper link connecting portion (212_1b), respectively, may be used to couple the first rotation member (211) to the first link member (215). According to one embodiment, the first rotating member (211) may be formed of a material (e.g., a metal material) having a certain strength or higher that can withstand friction that may occur with the fixed bracket (213) and the first link member (215) while the hinge motion is repeated. A part of the first wing plate (131 of FIG. 2) among the wing plates (131, 132 of FIG. 2) may be fixed to the first rotating member (211). As an example, when the hinge structure 201 is the first hinge structure (200a of FIG. 2), the first rotating member (211) may be coupled with the first wing plate (131 of FIG. 2), and when the hinge structure 201 is the second hinge structure (200b of FIG. 2), the first rotating member (211) may be coupled with the second wing plate (132 of FIG. 2). In this regard, the first rotating member (211) may include at least one hole or groove used for coupling with the first wing plate (131 of FIG. 2). According to one embodiment, the second rotational member (212) may be fastened to the other side of the fixed bracket (213) (e.g., the second rail (213a2)) so as to enable a hinge movement. In this regard, the second rotational member (212) may include a second upper rotational body (212_1), a second lower rotational body (212_2), and a second rotational elastic body (212_3) (or an elastic body or elastic member of the second rotational member (212)). According to one embodiment, at least a portion of an upper surface of the second rotational member (212) may be formed flat. In order for the second rotational elastic body (212_3) to be positioned between the second upper rotational body (212_1) and the second lower rotational body (212_2), a groove may be formed on one side (e.g., the side facing the y-axis direction) of the second upper rotational body (212_1) and one side (e.g., the side facing the -y-axis direction) of the second lower rotational body (212_2) so that a portion of the second rotational elastic body (212_3) may be inserted therein. Alternatively, grooves into which the second rotational elastic body (212_3) may be inserted may be formed on each of the sides where the second upper rotational body (212_1) and the second lower rotational body (212_2) are adjacent to each other. This structure may include the same structure as the first rotational member (211). The second upper rotation body (212_1) may have a second upper rail structure (212_1a) formed on one side (e.g., -x-axis edge) and a second upper link connection part (212_1b) formed on the other side (e.g., x-axis edge). The second lower rotation body (212_2) may have a second lower rail structure (212_2a) formed on one side (e.g., -x-axis edge) and a second lower link connection part (212_2b) formed on the other side (e.g., x-axis edge). The second rotational elastic body (212_3) is disposed between the second upper rotational body (212_1) and the second lower rotational body (212_2) in the same or similar manner as the first rotational elastic body (211_3), and can exert elastic force to push the second upper rotational body (212_1) and the second lower rotational body (212_2) in the -y-axis or y-axis direction, respectively. With this structure, the second upper rotational body (212_1) and the second lower rotational body (212_2) can be more firmly coupled to the second rail (213a2) of the upper fixed bracket (213a). In addition, the second rotational elastic body (212_3) can prevent the second rotational member (212) from being separated from the second rail (213a2) while the second rotational member (212) rotates within the second rail (213a2). The second upper rail structure (212_1a) and the second lower rail structure (212_2a) may be arranged at symmetrical positions with the second rotational elastic body (212_3) interposed therebetween. As an example, the second upper rail structure (212_1a) and the second lower rail structure (212_2a) may include a rail structure that is convex in the -z-axis direction. This structure may have the same or similar shape as the first upper rail structure (211_1a) and the first lower rail structure (211_2a). The side of the second upper rail structure (212_1a) may be coupled, for example, with one side of the second rail (213a2) (e.g., a part of the second rail (213a2) arranged on the upper side (213a3) of the fixed bracket), and the side of the second lower rail structure (212_2a) may be coupled, for example, with the other side of the second rail (213a2) (e.g., another part of the second rail (213a2) arranged on the lower side (213a4) of the fixed bracket). The bottom surfaces of the second upper rail structure (212_1a) and the second lower rail structure (212_2a) may be arranged to face the bottom surface of the second rail (213a2). The second upper rail structure (212_1a) may be arranged parallel to the first upper rail structure (211_1a) in the x-axis direction (or in a line based on the x-axis direction), and the second lower rail structure (212_2a) may be arranged parallel to the second upper rail structure (212_1a) in the x-axis direction (or in a line based on the x-axis direction). The second upper link connecting portion (212_1b) may include a hole penetrating from the -y-axis in the y-axis direction, and the second upper link connecting portion (212_1b) may include a hole penetrating from the -y-axis in the y-axis direction and aligned to be connected to the hole formed in the second upper link connecting portion (212_1b) in the y-axis direction. The second upper link connecting portion (212_1b) and the second lower link connecting portion (212_2b) may be mounted or fastened to the second link member (216). In this process, the holes formed in the second upper link connecting portion (212_1b) and the second upper link connecting portion (212_1b), respectively, may be used to couple the second rotation member (212) to the second link member (216). A predetermined space is formed between the second upper link connecting portion (212_1b) and the second lower link connecting portion (212_2b), and a second link elastic body (216b) (or an elastic body of the second link member (216)) disposed on the second link member (216) can be inserted (or placed) into the space. Similar to or identical to this structure, a predetermined space is formed between the first upper link connecting portion (211_1b) and the first lower link connecting portion (211_2b), and a first link elastic body (215b) (or an elastic body of the first link member (215)) can be inserted (or placed) into the space between the first upper link connecting portion (211_1b) and the first lower link connecting portion (211_2b). The second upper link connecting portion (212_1b) and the second lower link connecting portion (212_2b) may be positioned symmetrically on both sides (e.g., x-axis and -x-axis) with respect to the fixed bracket (213). Referring to FIG. 6, the first upper link connecting portion (211_1b) and the first lower link connecting portion (211_2b) may be coupled to the first link member (215) by the first link fastening member (215a) forming the fifth axis (axis_A3).The second upper link connecting portion (212_1b) and the second lower link connecting portion (212_2b) can be connected to the second link member (216) by the second link fastening member (216a) forming the sixth axis (axis_A4). According to one embodiment, the second rotating member (212) may generate friction with the fixed bracket (213) and the second link member (216) while the hinge motion is repeated similarly to the first rotating member (211), and may be formed of a material (e.g., a metal material) having a certain strength or higher that can withstand this. For example, the second rotating member (212) may be formed of the same material as the first rotating member (211). A part of the second wing plate (132 of FIG. 2) among the wing plates (131, 132 of FIG. 2) may be fixed to the second rotating member (212). For example, when the hinge structure 201 is the first hinge structure (200a of FIG. 2), the second rotation member (212) can be coupled with the second wing plate (132 of FIG. 2), and when the hinge structure 201 is the second hinge structure (200b of FIG. 2), the second rotation member (212) can be coupled with the first wing plate (131 of FIG. 2). In this regard, the second rotation member (212) can include at least one hole or groove used to be coupled with the second wing plate (132 of FIG. 2). The second rotation member (212) can move in a direction opposite to that of the first rotation member (211). For example, while the foldable electronic device (100) is folded (or unfolded), the first upper rail structure (211_1a) and the first lower rail structure (211_2a) of the first rotational member (211) may rotate in place in a counterclockwise (or clockwise) direction, while the second upper rail structure (212_1a) and the second lower rail structure (212_2a) of the second rotational member (212) may rotate in place in a clockwise (or counterclockwise) direction. According to one embodiment, the first link member (215) may include a structure coupled and fixed to one side of the first housing (110 of FIG. 2). The first link member (215) may include a first upper link sidewall (215_2) (or the first sidewall of the first link member (215)) and a first lower link sidewall (215_3) (or the second sidewall of the first link member (215)) that extend in the z-axis direction from both sides (e.g., the -y-axis and the y-axis edge) of the first link body (215_1). In addition, the first link member (215) may include a first link elastic body (215b), a first link fastening member (215a), and a first link fastening ring (215c). A part of a first rotational member (211) (e.g., a first upper link connecting portion (211_1b) and a first lower link connecting portion (211_2b)) is arranged (or coupled or fastened, or secured) between the first upper link side wall (215_2) and the first lower link side wall (215_3) of the first link member (215), and a structure may be included in which the x-axis edge of the first rotational member (211) is supported by the first link body (215_1). The first upper link side wall (215_2) may include a hole (e.g., a hole penetrating from the -y axis to the y axis direction) into which a first link fastening member (215a) is inserted, and the first lower link side wall (215_3) may include a hole (e.g., a hole penetrating from the -y axis to the y axis direction) formed in a position parallel to the hole formed in the first upper link side wall (215_2) into which a first link fastening member (215a) is inserted. In a state where the first upper link connecting portion (211_1b) and the first lower link connecting portion (211_2b) of the first rotation member (211) are placed between the first upper link side wall (215_2) and the first lower link side wall (215_3), the first link elastic body (215b) can be placed in a space between the first upper link connecting portion (211_1b) and the first lower link connecting portion (211_2b). The hole formed in the first upper link side wall (215_2), the hole formed in the first lower link side wall (215_3), the hole formed in the first upper link connecting portion (211_1b), and the hole formed in the first lower link connecting portion (211_2b) are aligned parallel to each other in the y-axis direction, and in a state where the holes are aligned, the first link fastening member (215a) can be placed by penetrating the holes. Accordingly, the first link fastening member (215a) may be positioned by penetrating the hole formed in the first upper link side wall (215_2), the hole formed in the first lower link side wall (215_3), the hole formed in the first upper link connecting portion (211_1b), and the hole formed in the first lower link connecting portion (211_2b), and then may be fixed by the first link fastening ring (215c) to the side wall facing the y-axis of the first lower link side wall (215_3). Accordingly, the first rotational member (211) may perform a rotational motion (or a rotational motion of one edge of the first rotational member (211) including the fifth axis (axis_A3)) within a certain angular range based on the fifth axis (axis_A3) by the first link fastening member (215a). At least one structure (e.g., a hole or a groove) used to secure the first link member (215) to the first housing (110 of FIG. 2) may be formed on at least one of the first upper link side wall (215_2) and the first lower link side wall (215_3). The first link member (215) may be arranged parallel to or integral with the third link member (223) in the -y-axis (or y-axis) direction. According to one embodiment, the second link member (216) may include a structure coupled and fixed to one side of the second housing (120 of FIG. 2). Similar to the first link member (215), the second link member (216) may include a second upper link sidewall (216_2) (or the first sidewall of the second link member (216)) and a second lower link sidewall (216_3) (or the second sidewall of the second link member (216)) that extend in the z-axis direction from both sides (e.g., the -y-axis and the y-axis edges) of the second link body (216_1). In addition, the second link member (216) may include a second link elastic body (216b), a second link fastening member (216a), and a second link fastening ring (216c). The second link member (216) is positioned symmetrically with respect to the first link member (215) with respect to the center line of the hinge structure (201) (e.g., the horizontal center line of the fixed bracket (213), the center line in the direction parallel to the y-axis), and may have a symmetrical structure. According to one embodiment, a part of a second rotational member (212) (e.g., a second upper link connecting portion (212_1b) and a second lower link connecting portion (212_2b)) is arranged (or coupled or fastened, or secured) between a second upper link side wall (216_2) and a second lower link side wall (216_3) of the second link member (216), and may be arranged such that the x-axis edge of the second rotational member (212) is supported by the second link body (216_1). The second upper link side wall (216_2) may include a hole (e.g., a hole penetrating from the -y axis to the y axis direction) into which a second link fastening member (216a) is inserted, and the second lower link side wall (216_3) may include a hole (e.g., a hole penetrating from the -y axis to the y axis direction) formed in a position parallel to the hole formed in the second upper link side wall (216_2) into which a second link fastening member (216a) is inserted. The second upper link connecting portion (212_1b) and the second lower link connecting portion (212_2b) of the second rotation member (212) may be arranged between the second upper link side wall (216_2) and the second lower link side wall (216_3). The second link elastic body (216b) may be arranged in a space between the second upper link connecting portion (212_1b) and the second lower link connecting portion (212_2b). The hole formed in the second upper link side wall (216_2), the hole formed in the second lower link side wall (216_3), the hole formed in the second upper link connecting portion (212_1b), and the hole formed in the second lower link connecting portion (212_2b) may be aligned in a parallel manner in the y-axis direction. In a state where the holes are aligned, the second link fastening member (216a) may be arranged to penetrate the holes. Accordingly, the second link fastening member (216a) may be positioned by penetrating the hole formed in the second upper link side wall (216_2), the hole formed in the second lower link side wall (216_3), the hole formed in the second upper link connecting portion (212_1b), and the hole formed in the second lower link connecting portion (212_2b), and then one side thereof may be fixed by the second link fastening ring (216c) to the side wall facing the y-axis of the second lower link side wall (216_3). Accordingly, the second rotational member (212) may perform a rotational motion (or a rotational motion of one edge of the second rotational member (212) including the sixth axis (axis_A4)) within a certain angular range based on the sixth axis (axis_A4) by the second link fastening member (216a). At least one structure (e.g., a hole or a groove) used to secure the second link member (216) to the second housing (120 of FIG. 2) may be formed on at least one of the second upper link side walls (216_2) and the second lower link side walls (216_3). The second link member (216) may be arranged parallel to or integral with the fourth link member (224) in the -y-axis (or y-axis) direction. According to one embodiment, the third link member (223) may include a structure in which a part of the first arm member (221) (e.g., the first arm portion (221_1) of the first arm member (221)) is placed (or fastened, coupled, or secured). The third link member (223) may include a third link body (223_1), a third upper link sidewall (223_2) (or a first sidewall of the third link member (223)) and a third lower link sidewall (223_3) (or a second sidewall of the third link member (223)) that extend in the z-axis direction from both sides (e.g., the x-axis and -x-axis edges) of the third link body (223_1). The third upper link side wall (223_2) may be formed with a rail (or a rail groove into which the protruding rail is inserted) protruding in the direction of the third lower link side wall (223_3), and the third lower link side wall (223_3) may be formed with a rail (or a rail groove into which the protruding rail is inserted) protruding in the direction of the third upper link side wall (223_2). The rails may be respectively fastened to one side (e.g., a rail groove or a protruding rail formed toward the -y-axis direction) and the other side (e.g., a rail groove or a protruding rail formed toward the y-axis direction) of the first arm portion (221_1). The third upper link side wall (223_2) and the third lower link side wall (223_3) may be formed with a structure (e.g., at least one hole or groove) used to fix the third link member (223) to the first housing (110 of FIG. 2). An empty space is formed between the third upper link side wall (223_2) and the third lower link side wall (223_3), and a first arm part (221_1) of a first arm member (221) is placed in the empty space, and the first arm part (221_1) can slide along rails formed in the third link member (223). Meanwhile, in the illustrated drawing, the third link member (223) and the first link member (215) are illustrated as being separated, but the present invention is not limited thereto.For example, the third link member (223) may be integrated with the first link member (215). Additionally, the third link member (223) may further include a third link elastic body (225) (or an elastic body of the third link member (223)) that is arranged on the bottom surface of the third link body (223_1) and supports the first arm member (221) coupled with the rail in the z-axis direction. The third link elastic body (225) has one side mounted on the third link body (223_1) and supports the rear surface (e.g., a surface observed in the -z-axis direction) of the first arm member (221) coupled with the third link member (223), and may exert elastic force in the z-axis direction or in a direction at a certain angle between the -x-axis and the z-axis. Based on this, since the first arm member (221) and the third link member (223) are in closer contact while the first arm member (221) performs a hinge operation, the occurrence of flow due to an irregular gap between the first arm member (221) and the third link member (223) is suppressed, so that the first arm member (221) can perform a more solid sliding operation with improved flow. According to one embodiment, the fourth link member (224) may include a structure in which a part of the second arm member (222) (e.g., the second arm portion (222_1) of the second arm member (222)) is disposed (or fastened, coupled, or secured). The fourth link member (224) may include a fourth link body (224_1), a fourth upper link sidewall (224_2) (or a first sidewall of the fourth link member (224)) and a fourth lower link sidewall (224_3) (or a second sidewall of the fourth link member (224)) that extend in the z-axis direction from both sides (e.g., x-axis and -x-axis edges) of the fourth link body (224_1). The fourth link member (224) may have a size and shape that are the same as or similar to those of the third link member (223). The fourth link member (224) may be arranged symmetrically with respect to the horizontal center line of the fixed bracket (213). According to one embodiment, a rail (or a rail groove into which a protruding rail is inserted) may be formed on the fourth upper link side wall (224_2) and a rail (or a rail groove into which a protruding rail is inserted) may be formed on the fourth lower link side wall (224_3) and a rail (or a rail groove into which a protruding rail is inserted) may be formed on the fourth lower link side wall (224_2). The rails formed on the fourth link member (224) may be fastened to one side (e.g., a rail groove or a protruding rail formed toward the -y-axis direction) and the other side (e.g., a rail groove or a protruding rail formed toward the y-axis direction) of the second arm portion (222_1) of the second arm member (222), respectively. A structure (e.g., at least one hole or groove) used to secure the fourth link member (224) to the second housing (120 in FIG. 2) may be formed on the fourth upper link side wall (224_2) and the fourth lower link side wall (224_3).A second arm part (222_1) is placed in the empty space between the fourth upper link side wall (224_2) and the fourth lower link side wall (224_3), and the second arm part (222_1) can slide along rails formed on the fourth link member (224). Additionally, the fourth link member (224) may further include a fourth link elastic body (226) (or an elastic body of the fourth link member (224)) that is arranged on the bottom surface of the fourth link body (224_1) and supports the second arm member (222) coupled to the rail in the z-axis direction. The fourth link elastic body (226) has the same or similar size and shape as the third link elastic body (225) described above within a certain error range, and may be arranged symmetrically with respect to the horizontal center line of the fixed bracket (213). The fourth link elastic body (226) may exert an elastic force to prevent movement of the second arm member (222) while the second arm member (222) slides on the fourth link member (224). At least one of the first to fourth link members (215, 216, 223, 224) may be formed of the same material. Alternatively, it may be formed at least partially of a different structure (e.g., an injection-molded product). Meanwhile, in the above description, the link members (215, 216, 223, 224) are illustrated as being separated, but the present disclosure is not limited thereto. For example, the first link member (215) and the third link member (223) may be connected to or integrated with each other, and the second link member (216) and the fourth link member (224) may be connected to or integrated with each other. According to one embodiment, the first arm member (221) may be arranged symmetrically with the second arm member (222) with respect to the y-axis or the -y-axis. The first arm member (221) may rotate in the x-axis to z-axis direction (or counterclockwise with respect to the direction from the fixed bracket extension (213a5) to the fixed bracket upper end (213a3)) while the portable electronic device (100) changes from an unfolded state to a folded state, with respect to the center of the first shaft (231), and may rotate in the z-axis to x-axis direction (or clockwise) while the portable electronic device (100) changes from a folded state to an unfolded state. The first arm member (221) may include a first arm portion (221_1) and a first main gear (221_2). The first arm portion (221_1) may include rail structures protruding in the -y-axis and y-axis directions, respectively, so as to be coupled with the third link member (223) to perform a sliding motion. The first arm portion (221_1) of the first arm member (221) may rotate within a predetermined angular range with respect to the seventh axis (axis_B1) within the third link member (223). The first main gear (221_2) is a portion coupled with the first shaft (231) and includes a through hole through which the first shaft (231) is disposed, and a gear pattern may be formed on at least a portion of the outer surface. The first main gear (221_2) may engage in gear coupling with an adjacent first gear (238a). At least a portion of the through hole of the first main gear (221_2) into which the first shaft (231) is inserted may include a D-cut shape. The above first main gear (221_2) can rotate within a certain angular range based on a third axis (axis_B3) based on the center line of the first shaft (231).To prevent the portable electronic device (100) from being rotated beyond a predetermined angle, the first arm portion (221_1) may include a hook or step provided to be caught on one side of the gear bracket (236) when rotated beyond a predetermined angle. According to one embodiment, the second arm member (222) may be arranged symmetrically with respect to the first arm member (221) with respect to the y-axis or the -y-axis. With respect to the y-axis (or with respect to the direction from the fixed bracket extension (213a5) to the upper end (213a3) of the fixed bracket), while the portable electronic device (100) changes from an unfolded state to a folded state, the second arm member (222) may rotate clockwise, and while the portable electronic device (100) changes from a folded state to an unfolded state, the second arm member (222) may rotate counterclockwise. The second arm member (222) may rotate in a direction opposite to the direction of movement of the first arm member (221). The second arm member (222) may include a second arm portion (222_1) and a second main gear (222_2). The second arm portion (222_1) is formed to extend in the direction of the fourth link member (224), and may include rail grooves (or rails) arranged in the -y-axis direction and the y-axis direction so as to be fastened with rails (or rail grooves) formed on the fourth link member (224). The second arm portion (222_1) is fastened to the fourth link member (224) and may perform a rotational motion within a certain angular range based on the eighth axis (axis_B2). The rotational motion may include a sliding motion that moves along the rails. The second main gear (222_2), similar to the first main gear (221_2), is a portion that is coupled with the second shaft (232), and includes a through hole through which the second shaft (232) is penetratingly arranged, and a gear pattern may be formed on at least a portion of the outer surface. The second main gear (222_2) may engage in gear coupling with an adjacent second gear (239a). At least a portion of the through hole of the second main gear (222_2) into which the second shaft (232) is inserted may have a D-cut shape.The second main gear (222_2) can rotate within a predetermined angle range based on the fourth axis (axis_B4) based on the center line of the second shaft (232). In order to prevent the portable electronic device (100) from rotating beyond a predetermined angle, the second arm portion (222_1) may include a hook or step provided to be caught on one side of the gear bracket (236) when rotating beyond a predetermined angle. According to various embodiments, the rail structure (or arc-shaped rail structure) formed on the first rotating member (211), the second rotating member (212), the first arm member (221) and the second arm member (222), the third and fourth link members (223, 224), and the fixed bracket (213) is formed as either a rail groove or a rail protrusion, and another configuration to be coupled may have the shape of a rail protrusion or a rail groove. As an example, the rail structure (211_2a, 211_1a) of the first rotating member (211) has a rail shape, but may be changed to a rail groove shape, and correspondingly, the shape of the fixed bracket (213) may be changed. Similarly, the rail structure of the second rotating member (212) and the fixed bracket (213), the first arm member (221) and the third link member (223), and the second arm member (222) and the fourth link member (224) can be designed so that one side has a groove or protrusion structure and the other side has a protrusion or groove structure so that they can be interlocked with each other. According to one embodiment, the first gear shaft (238) (or the first sub-shaft, the first auxiliary shaft) may be arranged parallel to the first shaft (231) and may have a rod shape that extends long in the z-axis direction. A first gear (238a) may be arranged on one side of the first gear shaft (238). Depending on the rotation of the first gear (238a), the first gear shaft (238) may rotate with respect to the ninth axis (axis_B5). The first gear (238a) may be arranged between the first main gear (221_2) and the second gear (239a) formed on the second gear shaft (239), and may be gear-coupled with the first main gear (221_2) and the second gear (239a). The first gear shaft (238) may be formed to have a different diameter depending on the position. For example, the first gear shaft (238) may have a diameter of a -y-axis edge larger than a diameter of a y-axis edge. The other side of the first gear shaft (238) (e.g., at least a portion in the y-axis direction from the center of the shaft) may be coupled (or arranged by penetrating holes formed in each configuration) to a central side of the first support member (248a), a central side of the second support member (248b), a central side of the cam member (241), the first upper auxiliary cam (244c) (or the third cam), the third cam elastic member (242c), the first sub-friction member (249c3), and a central side of the third support member (248c). According to one embodiment, the second gear shaft (239) (or the second sub-shaft, the second auxiliary shaft) may be arranged parallel to the first gear shaft (238) and may have a rod shape that extends long in the z-axis direction. A second gear (239a) may be arranged on one side of the second gear shaft (239). The second gear (239a) may be arranged between the second main gear (222_2) and the first gear (238a) formed on the first gear shaft (238), and may be gear-coupled with the second main gear (222_2) and the first gear (238a). Depending on the rotation of the second gear (239a), the second gear shaft (239) may rotate based on the 10th axis (axis_B6) formed at the center. Similar to the first gear shaft (238), the second gear shaft (239) may be formed to have a different diameter depending on the position. The other side of the second gear shaft (239) (e.g., at least a portion in the y-axis direction from the center of the shaft) may be coupled (or arranged by penetrating through holes formed in each configuration) with the central other side of the first support member (248a), the central other side of the second support member (248b), the central other side of the cam member (241), the second upper auxiliary cam (244d) (or the fourth cam), the fourth cam elastic member (242d), the second sub-friction member (249c4), and the central other side of the third support member (248c). According to one embodiment, the cam member (241) may include a first fixed cam portion (241a), a second fixed cam portion (241b), a third fixed cam portion (241c), and a fourth fixed cam portion (241d). The first fixed cam portion (241a) may be arranged from the center of the cam member (241) to the x-axis edge. The first fixed cam portion (241a) has a cylindrical shape surrounding a shaft hole (or the first hole, or the hole of the first fixed cam portion (241a)) formed to penetrate the y-axis or -y-axis direction at the center, and may include a cam pattern portion formed in a direction toward the y-axis and including at least one ridge and at least one valley. The first fixed cam portion (241a) may include a pattern in which ridges and valleys are repeatedly arranged to engage with a cam pattern (e.g., at least one ridge and at least one valley) formed on the first cam (244a). A first shaft (231) may be arranged to penetrate the shaft hole formed at the center of the first fixed cam portion (241a). The second fixed cam portion (241b) may be arranged at a -x-axis edge (or a position opposite or symmetrical to a position where the first fixed cam portion (241a) is formed centered on the cam portion (241)) from the center of the cam member (241). The second fixed cam portion (241b) may have a cylindrical shape surrounding a shaft hole (or a second hole, or a hole of the second fixed cam portion (241b)) formed at the center to penetrate the y-axis or -y-axis direction. As an example, the second fixed cam portion (241b) may have the same size and shape as the first fixed cam portion (241a) within a certain error range, and may be arranged in parallel. According to an embodiment, the second fixed cam portion (241b) may include a repeating pattern of mountains and valleys arranged to interlock with a cam pattern (e.g., at least one mountain and at least one valley) formed on the second cam (244b). The shaft hole formed at the center of the second fixed cam portion (241b) may have a designated shape (e.g., a cross-section in the z-axis direction that is circular) so that the second shaft (232) can pass through it. The third fixed cam portion (241c) may be arranged between the first fixed cam portion (241a) and the second fixed cam portion (241b). The third fixed cam portion (241c) may have a cylindrical shape surrounding a shaft hole (or a third hole, or a hole of the third fixed cam portion (241c)) formed at the center to penetrate the y-axis or -y-axis direction. As an example, the third fixed cam portion (241c) may include a shaft hole having a smaller size than that of the first fixed cam portion (241a). According to an embodiment, the third fixed cam portion (241c) may include a repeating pattern of mountains and valleys arranged to engage with a cam pattern (e.g., at least one mountain and at least one valley) formed on the third cam (244c). The size of the cam pattern formed in the third fixed cam portion (241c) may be formed smaller than the size of the cam pattern arranged in the first fixed cam portion (241a). The shaft hole formed in the center of the third fixed cam portion (241c) may have a designated shape (e.g., a cross-section in the z-axis direction is circular) so that the first gear shaft (238) may pass through. The diameter (or area) of the z-axis cross-section of the first gear shaft (238) may be formed smaller than the diameter (or area) of the z-axis cross-section of the first shaft (231). Correspondingly, the diameter of the shaft hole in the center of the third fixed cam portion (241c) may be formed smaller than the diameter of the shaft hole of the first fixed cam portion (241a) into which the first shaft (231) is inserted. The fourth fixed cam portion (241d) may be arranged between the third fixed cam portion (241c) and the second fixed cam portion (241b). The fourth fixed cam portion (241d) may have a cylindrical shape surrounding a shaft hole (or the fourth hole, or the hole of the fourth fixed cam portion (241d)) formed to penetrate the y-axis or -y-axis direction in the center thereof. As an example, the fourth fixed cam portion (241d) may have the same size and shape as the third fixed cam portion (241c) within a certain error range. For example, the cam hole penetrating the center of the fourth fixed cam portion (241d) in the y-axis direction may have a size that is the same as or similar to the shaft hole size of the third fixed cam portion (241c). According to one embodiment, the fourth fixed cam portion (241d) may include a repeating pattern of mountains and valleys arranged to mesh with the cam pattern (e.g., at least one mountain and at least one valley) formed on the fourth cam (244d). The size of the cam pattern formed on the fourth fixed cam portion (241d) may be formed to be the same as or similar to the size of the cam pattern arranged on the third fixed cam portion (241c). The shaft hole formed at the center of the fourth fixed cam portion (241d) may have a designated shape (e.g., a cross-section in the z-axis direction is circular) so that the second gear shaft (239) may pass through. The diameter (or area) of the z-axis cross-section of the second gear shaft (239) may be formed to be similar to or identical to the diameter (or area) of the z-axis cross-section of the first gear shaft (238). In response to this, the diameter of the shaft hole at the center of the fourth fixed cam portion (241d) can be formed to be the same as or similar to the diameter of the shaft hole of the third fixed cam portion (241c) into which the first gear shaft (238) is inserted. According to one embodiment, a plurality of cams (244a, 244b, 244c, 244d) may be arranged between the first cam member (241) and the cam elastic members (242a, 242b, 242c, 242d). For example, a first cam (244a) may be arranged between a first fixed cam portion (241a) of a first cam member (241) and a first cam elastic member (242a), a second cam (244b) may be arranged between a second fixed cam portion (241b) of a second cam member (241) and a second cam elastic member (242b), a third cam (244c) may be arranged between a third fixed cam portion (241c) of a third cam member (241) and a third cam elastic member (242c), and a fourth cam (244d) may be arranged between a fourth fixed cam portion (241d) of a fourth cam member (241) and a fourth cam elastic member (242d). The plurality of cams (244a, 244b, 244c, 244d) may have shapes corresponding to the cam shapes of the facing cam members (241). For example, the first cam (244a) and the second cam (244b) may have a size and shape corresponding to the cam pattern of the first fixed cam portion (241a) and the second fixed cam portion (241b). The third cam (244c) and the fourth cam (244d) may have a size and shape corresponding to the cam pattern of the third fixed cam portion (241c) and the fourth fixed cam portion (241d). Accordingly, the sizes of the first cam (244a) and the second cam (244b) may be larger than the sizes of the third cam (244c) and the fourth cam (244d). The first cam (244a) may be inserted into the first shaft (231), the second cam (244b) may be inserted into the second shaft (232), the third cam (244c) may be inserted into the first gear shaft (238), and the fourth cam (244d) may be inserted into the second gear shaft (239). Meanwhile, in the above description, a structure in which the first cam (244a) and the second cam (244b) are formed larger than the third cam (244c) and the fourth cam (244d) has been exemplified, but the present invention is not limited thereto.For example, the sizes of the first cam (244a) and the second cam (244b) may be the same as the sizes of the third cam (244c) and the fourth cam (244d). Alternatively, the sizes of the first cam (244a) and the second cam (244b) may be formed smaller than the sizes of the third cam (244c) and the fourth cam (244d). Alternatively, the first cam (244a) and the third cam (244c) may be formed in a zigzag shape such that the first cam (244a) and the third cam (244c) have the same size, and the second cam (244b) and the fourth cam (244d) have the same size, but have different sizes from the first cam (244a) and the third cam (244c). When the size and shape of the cams (244a, 244b, 244c, 244d) are changed, the size and shape of the fixed cam parts (241a, 241b, 241c, 241d) of the cam member (241) may also be changed accordingly. According to one embodiment, a foldable electronic device having a display screen having a size greater than a certain size may require a torque greater than a certain size to maintain a flex mode (a mode that maintains a partially folded state within an angle range greater than 0 degrees and less than 180 degrees) during a folding or unfolding process. In an embodiment of the present disclosure, cam elastic members (242a, 242b, 242c, 242d) that provide elastic forces of different sizes may be included so as to provide a relatively greater force in relation to a folding operation of the foldable electronic device (100) while performing a stable folding or unfolding operation. As an example, some of the elastic members among the cam elastic members (242a, 242b, 242c, 242d) may be implemented as disc springs, and other elastic members may be implemented as coil springs. A plate-shaped disc spring may be used in multiple layers depending on conditions, and may have a smaller operating displacement than a coil spring under the same length condition, but may implement a greater force. According to one embodiment, a plurality of stacked disc springs are arranged on a first shaft (231) and a second shaft (232), and a plurality of friction members and support members are arranged on the same line, thereby converting the elastic force of cam elastic members (e.g., the first cam elastic member (242a) and the second cam elastic member (242b)) into surface pressure to provide high torque, thereby supporting maintenance of a flex mode of a foldable electronic device having a screen of a certain size or larger. According to one embodiment, the first cam elastic member (242a) (or the first elastic member, the first elastic body) may have a state in which a plurality of disk-shaped springs having a hole formed in the center and bent in the y-axis or -y-axis direction are overlapped or laminated. According to one embodiment, the disk spring may have a hollow interior, a hole formed in the center, and a dome shape protruding to one side. According to one embodiment, the disk spring may be provided in a circular band shape when observed in the z-axis direction, and may have a dome shape (or a shape including a certain inclination (inclination greater than 0 degrees and less than 90 degrees) from the edge to the center) in which the size of the x-axis cross-section decreases from the edge to the center when observed in the x-axis direction perpendicular to the z-axis. Each of the plurality of disk springs may have the same shape. Based on the protruding shape of the above disc spring, the disc spring may include a lower end (a portion having a relatively wider outer diameter than the upper end, or an edge) and an upper end (a portion having a relatively narrower inner diameter than the lower end, or a center portion where a hole into which a shaft is inserted is formed). The plurality of laminated disc springs of the first cam elastic member (242a) may be arranged so that the lower end faces each other and the upper end faces each other during the process of overlapping each other. According to one embodiment, the first cam elastic member (242a) may include a structure in which sets of first disc springs are laminated in a staggered manner, wherein the first disc springs are inserted into the inner side of other second disc springs (e.g., the upper outer side of the second disc spring is arranged so that the upper inner side of the first disc spring faces the upper outer side of the second type set of the plurality of disc springs, or the disc springs are overlapped). For example, the first cam elastic member (242a) may include a laminated state in which the lower outer side of a first set of a plurality of disc springs is overlapped and faces the lower outer side of a second type set of the plurality of disc springs, or the upper outer side of the first set faces the upper outer side of the second set. The first cam elastic member (242a) may include a state in which the first set and the second set are arranged in a zigzag manner. As an example, in the illustrated drawing, a state in which eight sets of multiple disc springs are overlapped is exemplified. However, the first cam elastic member (242a) of the present invention is not limited thereto, and the number of the sets may be adjusted. In addition, the first cam elastic member (242a) may include a structure in which the disc springs are laminated without being covered (e.g., a structure in which the upper outer side of one disc spring and the upper outer side of another disc spring are arranged so as to face each other, and the lower outer side of one disc spring and the lower outer side of the other disc spring are arranged so as to face each other). At least a part of the body of the first shaft (231) penetrating the first fixed cam portion (241a) and the first cam (244a) may be arranged at the center of the first cam elastic member (242a). The first cam elastic member (242a) is arranged between the cam member (241) and the shaft fixing portion (243), and as the shaft fixing portion (243) is fixed to one side of the foldable electronic device (100) (e.g., the hinge housing 150 of FIG. 2), an elastic force may be exerted to push the first cam (244a) toward the first fixed cam portion (241a) of the cam member (241). A plurality of friction members (e.g., a first friction member (249a1), a third friction member (249b1), a fifth friction member (249c1)) and a part of a support member (e.g., one side of the first support member (248a), one side of the second support member (248b), and one side of the third support member (248c)) may be disposed on the first shaft (231) on which the first cam elastic member (242a) is disposed. The first cam elastic member (242a) may provide elastic force to the above-described friction members and support members, thereby contributing to the formation of a relatively high torque compared to the third cam elastic member (242c). According to one embodiment, the second cam elastic member (242b) may be arranged to be spaced apart from the first cam elastic member (242a) by a specified distance, and may be arranged to contact one surface of the second cam (244b). The second cam elastic member (242b) (or the second elastic member, the second elastic body) may have a hole formed in the center similar to the first cam elastic member (242a) and may have a state in which a plurality of disk-shaped springs bent in the y-axis or -y-axis direction are overlapped. According to one embodiment, the number of disk springs of the second cam elastic member (242b) may be the same as the number of disk springs of the first cam elastic member (242a). The shape and size of the disk-shaped springs overlapped (or laminated) on the second cam elastic member (242b) may be the same as or similar to the shape and size of the disk-shaped springs overlapped (or laminated) on the first cam elastic member (242a) within a certain error range. The magnitude of the elastic force of the second cam elastic member (242b) may be the same as or similar to the magnitude of the elastic force of the first cam elastic member (242a) within a certain error range. According to one embodiment, the magnitude of the elastic force of the second cam elastic member (242b) (or the first cam elastic member (242a)) may be set to be greater than or equal to the magnitude of the elastic force of the third cam elastic member (242c) (or the fourth cam elastic member (242d)). At least a part of the body of the second shaft (232) penetrating the second fixed cam portion (241b) and the second cam (244b) may be arranged at the center of the second cam elastic member (242b). The second cam elastic member (242b) is arranged between the cam member (241) and the shaft fixing member (243), and as the shaft fixing member (243) is fixed to one side of the foldable electronic device (100) (e.g., the hinge housing 150 of FIG. 2), it can exert an elastic force to push the second cam (244b) toward the second fixed cam portion (241b) of the cam member (241).According to one embodiment, the second cam elastic member (242b) can provide elastic force to a plurality of friction members (e.g., the second friction member (249a2), the fourth friction member (249b2), and the sixth friction member (249c2)) inserted into the second shaft (232) and another part of the support member (e.g., the other side of the first support member (248a), the other side of the second support member (248b), and the other side of the third support member (248c)). Correspondingly, the second cam elastic member (242b) can contribute to the formation of a surface pressure or torque having the same or similar size as that of the first cam elastic member (242a). According to one embodiment, the third cam elastic member (242c) (or the third elastic member, the third elastic body) may include a coil spring (or spring) shape in which at least a portion of the first gear shaft (238) is disposed penetratingly at the center, and the length in the y-axis and -y-axis directions is formed longer than in other axial directions. The third cam elastic member (242c) is disposed between the first cam elastic member (242a) and the second cam elastic member (242b) in the x-axis or -x-axis direction, and the third cam elastic member (242c) may be disposed to exert an elastic force on the third cam (244c) facing (or contacting) the third fixed cam portion (241c) of the cam member (241). The size of the cross-section of the z-axis direction (or the size of the outer surface) of the third cam elastic member (242c) may be formed smaller than the size of the cross-section of the z-axis direction (or the maximum size) of the first cam elastic member (242a). The compression distance (or compression displacement) of the third cam elastic member (242c) in the y-axis direction or -y-axis direction may be formed longer (larger) than the compression distance (or compression displacement) of the first cam elastic member (242a). The magnitude of the elastic force of the third cam elastic member (242c) in the y-axis direction or -y-axis direction may be set to be less than or equal to the elastic force of the first cam elastic member (242a). According to one embodiment, the fourth cam elastic member (242d) (or the fourth elastic member, the fourth elastic body) may include a coil spring (or spring) shape in which at least a portion of the second gear shaft (239) is disposed penetratingly at the center, and the length in the y-axis and -y-axis directions is formed longer than in other axial directions. As an example, the fourth cam elastic member (242d) may be formed to have at least one of the same size and shape as the third cam elastic member (242c). The fourth cam elastic member (242d) is disposed between the third cam elastic member (242c) and the second cam elastic member (242b) in the x-axis or -x-axis direction, and the fourth cam elastic member (242d) may be disposed to exert an elastic force on the fourth cam (244d) facing (or contacting) the fourth fixed cam portion (241d) of the cam member (241). The size of the cross-section of the z-axis direction (or the size of the outer surface) of the fourth cam elastic member (242d) may be formed to be identical or similar to the size of the cross-section of the z-axis direction (or the size of the outer surface) of the third cam elastic member (242c). The compression distance of the fourth cam elastic member (242d) in the y-axis direction or the -y-axis direction may be formed to be identical or similar to the compression distance of the third cam elastic member (242c). The size of the elastic force of the fourth cam elastic member (242d) in the y-axis direction or the -y-axis direction may be set to be identical or similar to the size of the elastic force of the third cam elastic member (242c) within a certain error range. The above shaft fixing part (243) may include a shaft body (243_3), a first fixing part (243_1) in which a first shaft hole is formed, and a second fixing part (243_2) in which a second shaft hole is formed. The shaft body (243_3) may include a through hole that penetrates upwardly and downwardly (e.g., in the -z-axis direction from a point on the z-axis) and is used to fix the shaft fixing part (243) to a hinge housing (150 of FIG. 2). The first shaft hole formed in the first fixing part (243_1) is formed to penetrate in the y-axis or -y-axis direction, and the first shaft (231) may penetrate and be positioned therein. The shape of the first shaft hole may be provided in a cylindrical shape. The first fixing part (243_1) may support one side of the first cam elastic member (242a). The second shaft hole formed in the second fixed portion (243_2) is arranged parallel to the first shaft hole with respect to the y-axis, and the second shaft (232) can pass through and be arranged therein. The shape of the second shaft hole can be provided in a cylindrical shape. The second fixed portion (243_2) can support one side of the second cam elastic member (242b). The center of the shaft body (243_3) (e.g., between the first fixed portion (243_1) and the second fixed portion (243_2)) can include a first mounting groove in which one side (e.g., the y-axis edge) of the first gear shaft (238) is mounted, and a second mounting groove in which one side (e.g., the y-axis edge) of the second gear shaft (239) is mounted. At least some of the above-described plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) and the plurality of support members (248a, 248b, 248c) face each other, and when pressed by the pressure applied by the cam elastic members (242a, 242b, 242c, 242d), they can generate a frictional force when the hinge structure (201) rotates. The frictional force generated by the plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) can act as a torque for maintaining a specific angle of attachment during the folding or unfolding process of the foldable electronic device (100). As an example, the first friction member (249a1) may be disposed between one side of the first support member (248a) (e.g., the x-axis edge of the first support member (248a)) and one side of the second support member (248b) (e.g., the x-axis edge of the second support member (248b)), and the second friction member (249a2) may be disposed between the other side of the first support member (248a) (e.g., the -x-axis edge of the first support member (248a)) and the other side of the second support member (248b) (e.g., the -x-axis edge of the second support member (248b)). The third friction member (249b1) may be disposed between one side of the second support member (248b) and the rear surface of the portion of the cam member (241) where the first fixed cam portion (241a) is formed, and the fourth friction member (249b2) may be disposed between the other side of the second support member (248b) and the rear surface of the portion of the cam member (241) where the second fixed cam portion (241b) is formed. The fifth friction member (249c1) may be disposed between the first cam elastic member (242a) and one side of the third support member (248c) (e.g., the x-axis edge of the third support member (248c)), and the sixth friction member (249c2) may be disposed between the second cam elastic member (242b) and the other side of the third support member (248c) (e.g., the -x-axis edge of the third support member (248c)).The first sub-friction member (249c3) may be arranged between the fifth friction member (249c1) and the sixth friction member (249c2) with respect to the x-axis, and between one side of the center of the third cam elastic member (242c) and the third support member (248c) with respect to the y-axis. The second sub-friction member (249c4) may be arranged between the sixth friction member (249c2) and the first sub-friction member (249c3) with respect to the x-axis, and between the other side of the center of the third cam elastic member (242c) and the third support member (248c) with respect to the y-axis. The first fixing nut (249d1) may be fastened to one side (y-axis edge) of the first shaft (231) protruding through the first fixing portion (243_1) of the shaft fixing portion (243). According to one embodiment, at least a portion of one side of the first shaft (231) includes a bolt shape (or a bolt pattern), and the first fixing nut (249d1) may be fastened to at least a portion of one side of the first shaft (231) by a bolt and nut combination. The second fixing nut (249d2) may be fastened to one side (y-axis edge) of the second shaft (232) protruding through the second fixing portion (243_2) of the shaft fixing portion (243). According to one embodiment, at least a portion of one side of the second shaft (232) includes a bolt shape (or bolt pattern), and the first fixing nut (249d1) can be fastened to at least a portion of one side of the second shaft (232) by a bolt and nut combination in the same or similar manner as the first fixing nut (249d1). The fixing nuts (249d1, 249d2) (or fixing members, fixing bodies) can prevent the first shaft (231) and the second shaft (232) from flowing or separating. At least some of the plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) can be arranged to improve wear of adjacent other structures. Meanwhile, at least some of the above-described plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) may be omitted. Alternatively, additional friction members may be added to the hinge structure (201). In addition, a major feature of the present disclosure is that cam elastic members of different shapes are used, so that at least some of their positions, arrangement forms, sizes, or shapes may be modified or changed.In addition, the hinge structure (201) of the present disclosure does not necessarily require all structures related to the hinge operation other than the cam elastic members, and at least some of the structures may be excluded or replaced with other structures in terms of the technical understanding of a person skilled in the art. For example, as mentioned above, at least some of the link members (215, 216, 223, 224) may be provided in an integrated shape with the first housing (the first housing 110 of FIG. 2) and the second housing (the second housing 120 of FIG. 2), and the fixed bracket extension (213a5) may be removed from the fixed bracket (213), and the fixed bracket (213) may include only the upper fixed bracket (213a). In addition, the gear bracket (236) may be omitted as needed, and the fixed nuts (249d1, 249d2) may be replaced with E-rings. In addition, although the rotating members (211, 212) are exemplified as having a structure including two upper and lower rotating bodies, the rotating members (211, 212) may have an integrated structure that does not include a separate rotating elastic body. Correspondingly, in the first link member (215) and the second link member (216), the first link fastening member (215a) and the second link fastening member (216a), the first link elastic body (215b), the second link elastic body (216b), the first link fastening ring (215c), and the second link fastening ring (216c) may be excluded, and a rail (or rail groove) having a certain curvature may be included. Correspondingly, the link connecting portions of the first rotating member (211) and the second rotating member (212) may be changed to a rail groove (or rail). FIG. 7 is a drawing showing an example of a type of cam member and cams in a hinge structure according to one embodiment. FIG. 8 is a drawing showing a change in torque during an unfolding and folding operation of a hinge structure according to one embodiment. Referring to FIGS. 1 to 7, according to one embodiment, the hinge structure (201) may include at least a cam member (241), cams (244a, 244b, 244c, 244d), and cam elastic members (242a, 242b, 242c, 242d). Additionally, the hinge structure (201) may include a second support member (248b), a third friction member (249b1), and a fourth friction member (249b2), and may further include shafts disposed to penetrate each of the components. Some of the cam elastic members (242a, 242b, 242c, 242d) may be configured with a different type from the remaining some of the cam elastic members. For example, the first cam elastic member (242a) and the second cam elastic member (242b) may include a structure in which disk springs are laminated. The third cam elastic member (242c) and the fourth cam elastic member (242d) may include coil springs. The detent force variation (e.g., 21.1 kgf, which may be changed according to a design change) of the first cam elastic member (242a) and the second cam elastic member (242b) configured with the disk springs may be set to be greater than the detent force variation (e.g., 6.5 kgf, which may be changed according to a design change) of the third cam elastic member (242c) and the fourth cam elastic member (242d) including the coil springs. As an example, the total compression amount (or compressible amount) of the disc spring may be set to the level of 0.2 to 0.25 mm when six disc springs are laminated at a maximum of 0.05 mm each and the total maximum compression amount is less than 0.3 mm, and considering the margin for plastic deformation and torque setup, the total compression amount may be set to the level of 0.2 to 0.25 mm. When the cam stroke portion for implementing the Detent exceeds a certain size compared to the total compression amount, the torque decreases rapidly in the Detent section, so the cam stroke (the spring operating displacement of the flex section and the Open and Close sections of the foldable electronic device (100)) may be applied to a maximum of 0.1 or less (e.g., 0.05 to 0.1). When a coil spring with a total compression amount of 2.0 mm has a stroke of 0.25, the force reduction amount of the coil spring is -12.3%, which can be maintained at around 10%. Disc springs with a total compression of 0.25 mm or less can experience a force reduction of more than 20%, which is approximately -20.6% for 0.05 strokes, and when a cam stroke of 0.08 mm is applied, disc springs can experience a torque reduction of more than -30%.Accordingly, in the hinge structure (201) of the present disclosure, the cam structure (e.g., the first fixed cam portion (241a) and the second fixed cam portion (241b), the first cam (244a) and the second cam (244b)) pressed by the first cam elastic member (242a) and the second cam elastic member (242b) including the disc springs can have a cam operating amount (e.g., 0.05 mm) smaller than the cam operating amount (e.g., 0.25 mm) of the cam structure (e.g., the third fixed cam portion (241c) and the fourth fixed cam portion (241d), the third cam (244c) and the fourth cam (244d)) pressed by the third cam elastic member (242c) and the fourth cam elastic member (242d). Through the above-described structure, the hinge structure (201) of the present disclosure can have a cam operating amount (e.g., 0.05 mm) smaller than the cam operating amount (e.g., 0.25 mm) of the cam structure (e.g., the third fixed cam portion (241c) and the fourth fixed cam portion (241d), the third cam (244c) and the fourth cam (244d)). The first cam elastic member (242b) is set to provide high surface pressure or torque, and the third cam elastic member (242c) and the fourth cam elastic member (242d) support providing a more stable detent feeling in a folding or unfolding operation situation of the foldable electronic device (100). According to one embodiment, the spring displacements of the first cam elastic member (242a) and the second cam elastic member (242b) composed of the disk springs may be set smaller than the spring displacements of the third cam elastic member (242c) and the fourth cam elastic member (242d) including the coil springs. Meanwhile, the above-described numerical values ​​are only examples and may vary depending on a change in the size of the hinge structure (201), and thus the present disclosure is not limited to the above-described numerical values. The second support member (248b) may include, for example, a first support portion (248b_1) into which a first shaft (231) is inserted, a second support portion (248b_2) into which a second shaft (232) is inserted, a first central portion (248b_3) into which a first gear shaft (238) is inserted, and a second central portion (248b_4) into which a second gear shaft (239) is inserted. The first support portion (248b_1), the second support portion (248b_2), the first central portion (248b_3), and the second central portion (248b_4) may have a connection structure (241_con). The first support portion (248b_1) and the second support portion (248b_2) may include holes corresponding to the sizes of the z-axis cross sections of the first shaft (231) and the second shaft (232), respectively. The first central portion (248b_3) and the second central portion (248b_4) may include holes corresponding to the sizes of the z-axis cross sections of the first gear shaft (238) and the second gear shaft (239), respectively. When the sizes of the z-axis cross sections of the first gear shaft (238) and the second gear shaft (239) are formed smaller than the sizes of the z-axis cross sections of the first shaft (231) and the second shaft (232), the sizes of the holes formed in the first central portion (248b_3) and the second central portion (248b_4), respectively, may be formed smaller than the sizes of the holes formed in the first support portion (248b_1) and the second support portion (248b_2), respectively. The above cam member (241) may include a first fixed cam portion (241a) disposed between the first cam (244a) and the third friction member (249b1) to form a first contact angle (a1), a second fixed cam portion (241b) disposed between the second cam (244b) and the fourth friction member (249b2) to form a first contact angle (a1), a third fixed cam portion (241c) disposed between the third cam (244c) and the first central portion (248b_3) of the second support member (248b) to form a second contact angle (a2), and a fourth fixed cam portion (241d) disposed between the fourth cam (244d) and the second central portion (248b_4) of the second support member (248b) to form a second contact angle (a2). The inside of the first fixed cam portion (241a) may be formed with a through hole into which the first shaft (231) may be inserted. The first fixed cam portion (241a) may be maintained in a fixed state even when the first shaft (231) rotates. In this regard, the through hole may have a circular z-axis cross section so that the first shaft (231) may rotate. A cam pattern may be formed on one side of the first fixed cam portion (241a) (e.g., a side facing the y-axis direction), and the other side of the first fixed cam portion (241a) (e.g., a direction facing the -y-axis direction or the third friction member (249b1)) may be formed flat. Alternatively, the other side of the first fixed cam portion (241a) may have a shape corresponding to the shape of the third friction member (249b1). For example, when the third friction member (249b1) includes a shape protruding in the y-axis direction, at least a portion of the other side of the first fixed cam portion (241a) may include a shape engraved in the y-axis direction. The cam pattern formed on the first fixed cam portion (241a) may have a shape corresponding to the cam pattern of the first cam (244a) (e.g., a mountain and a valley having a height and length similar to those of the mountains and valleys formed on the first cam (244a), and a first inclination). Alternatively, the curve curvature of the cam pattern formed on the first fixed cam portion (241a) may have a curve curvature corresponding to the cam pattern of the first cam (244a). The second fixed cam portion (241b) may have a structure substantially the same as or similar to that of the first fixed cam portion (241a). For example, a through hole may be formed inside the second fixed cam portion (241b) into which the second shaft (232) may be inserted. The second fixed cam portion (241b) may have a circular cross-section in the z-axis shape of the through hole so that the second shaft (232) may be maintained in a fixed state even when the second shaft (232) rotates. A cam pattern may be formed on one side of the second fixed cam portion (241b) (e.g., a side in the y-axis direction), and the other side of the second fixed cam portion (241b) (e.g., a side in the -y-axis direction or a side facing the fourth friction member (249b2)) may be formed flat, or may include a shape corresponding to the shape of the fourth friction member (249b2) (e.g., a shape in which at least a portion is sunken or engraved in the -y-axis direction). The cam pattern formed on the second fixed cam portion (241b) may have a shape corresponding to the cam pattern of the second cam (244b) (e.g., a mountain and a valley having a height and length similar to those of the mountain and valley formed on the second cam (244b), and a mountain and a valley having a first inclination). The inclination of the cam pattern formed on the second fixed cam portion (241b) may be the same as or similar to the inclination of the cam pattern formed on the first fixed cam portion (241a). Alternatively, the curve curvature of the cam pattern formed on the second fixed cam portion (241b) may have a curve curvature corresponding to the cam pattern of the second cam (244b). The third fixed cam portion (241c) is disposed between the first fixed cam portion (241a) and the second fixed cam portion (241b), is physically connected to the first fixed cam portion (241a), and may have a connection structure that can be physically connected to the fourth fixed cam portion (241d). As various embodiments, the cam member (241) may include a connection structure (241_con) that connects at least a part or all of the first to fourth fixed cam portions. A through hole into which the first gear shaft (238) can be inserted may be formed inside the third fixed cam portion (241c). Since the third fixed cam portion (241c) is connected to the first fixed cam portion (241a), the foldable electronic device (100) can be maintained in a fixed state even when the hinge operates in a folded or unfolded state. In this regard, the third fixed cam portion (241c) may have a circular perforated shape of the z-axis cross-section so that the first gear shaft (238) can rotate. The size of the z-axis cross-section of the third fixed cam portion (241c) may be formed smaller than the size of the z-axis cross-section of the first fixed cam portion (241a). However, the size of the z-axis cross-section of the third fixed cam portion (241c) of the present disclosure may be set to be equal to or larger than the z-axis cross-section size of the first fixed cam portion (241a). A cam pattern is formed on one side of the third fixed cam portion (241c) (e.g., a side facing the y-axis direction), and the other side of the third fixed cam portion (241c) (e.g., a direction facing the -y-axis direction or the first central portion (248b_3) of the second support member (248b)) may be formed flat. The cam pattern formed on the third fixed cam portion (241c) may have a shape corresponding to the cam pattern of the third cam (244c) (e.g., a mountain and a valley having a similar height and length to the mountain and valley formed on the third cam (244c) and a second slope). Alternatively, the curve curvature of the cam pattern formed on the third fixed cam portion (241c) may have a curve curvature corresponding to the cam pattern of the third cam (244c).The second slope (e.g., slope of a mountain or valley) of the cam pattern formed on the third fixed cam portion (241c) may be formed to be greater than the first slope of the cam pattern formed on the first fixed cam portion (241a). Alternatively, the first slope may be formed to be gentler than the second slope. According to one embodiment, the length of the slope of the mountain of the third fixed cam portion (241c) may be formed to be longer than the length of the slope of the mountain of the first fixed cam portion (241a). Alternatively, the curvature of the curve of the cam pattern formed on the third fixed cam portion (241c) (or the third cam (244c)) may be formed to be smaller (or more gentle) than the curvature of the curve of the cam pattern formed on the first fixed cam portion (241a) (or the first cam (244a)). Alternatively, the curvature of the curve of the cam pattern formed on the first fixed cam portion (241a) (or the first cam (244a)) may be formed to be larger (or more steep) than the curvature of the curve of the cam pattern formed on the third fixed cam portion (241c) (or the third cam (244c)). The inclined surface may be at least a portion (or a point) of the curve. Or, at least a part of the inclined surface may have a curvature. The fourth fixed cam portion (241d) is disposed between the third fixed cam portion (241c) and the second fixed cam portion (241b), is physically connected to the third fixed cam portion (241c), and is physically connected to the second fixed cam portion (241b) so as to have a fixed structure that does not rotate. The fourth fixed cam portion (241d) may have at least one of the same shape, size, and material as the third fixed cam portion (241c). As an example, the fourth fixed cam portion (241d) has a size of a z-axis cross-section that is the same as the size of a z-axis cross-section of the third fixed cam portion (241c), and at least a part of a second gear shaft (239) may be disposed to penetrate an internal hole formed in a circular shape. The fourth fixed cam portion (241d) has a cam pattern formed on a side facing the y-axis, and can be arranged to engage with the fourth cam (244d) in response to the rotation of the foldable electronic device (100). The second inclination formed in the cam pattern of the fourth fixed cam portion (241d) can have a size that is the same as or similar to the inclination formed in the third fixed cam portion (241c). Alternatively, the curvature of the curve of the cam pattern of the fourth fixed cam portion (241d) can have a size that is the same as or similar to the curvature of the curve of the cam pattern formed in the third fixed cam portion (241c). Accordingly, the second inclination formed in the cam pattern of the fourth fixed cam portion (241d) can be set to be larger than the inclination formed in the first fixed cam portion (241a) (or the second fixed cam portion (241b)). The slope length of the mountain among the cam patterns of the fourth fixed cam portion (241d) may be formed to be the same as the slope length of the mountain among the cam patterns of the third fixed cam portion (241c). Correspondingly, the slope length of the mountain among the cam patterns of the fourth fixed cam portion (241d) may be formed to be longer than the slope length of the mountain among the cam patterns of the second fixed cam portion (241b).Alternatively, the curvature of the curve of the cam pattern formed on the fourth fixed cam portion (241d) (or the fourth cam (244d)) may be formed smaller (or more gently) than the curvature of the curve of the cam pattern formed on the second fixed cam portion (241b) (or the second cam (244b)). Alternatively, the curvature of the curve of the cam pattern formed on the second fixed cam portion (241b) (or the second cam (244b)) may be formed larger (or more steeply) than the curvature of the curve of the cam pattern formed on the fourth fixed cam portion (241d) (or the fourth cam (244d)). The above cams (244a, 244b, 244c, 244d) may include a first cam (244a) disposed between a first cam elastic member (242a) and a first fixed cam portion (241a), a second cam (244b) disposed between a second cam elastic member (242b) and a second fixed cam portion (241b), a third cam (244c) disposed between a third cam elastic member (242c) and a third fixed cam portion (241c), and a fourth cam (244d) disposed between a fourth cam elastic member (242d) and a fourth fixed cam portion (241d). A first shaft (231) may be inserted into the first cam (244a). The first cam (244a) may have an internal shape corresponding to the z-axis cross-sectional shape of the first shaft (231) (e.g., at least a portion of the internal shape has a D-cut shape) so as to rotate in response to the rotation of the first shaft (231). The first cam (244a) may include a cam pattern (or cam structure) corresponding to the first fixed cam portion (241a). For example, the first cam (244a) includes mountains and valleys having a shape opposite to (or interlocked with) mountains and valleys formed in the first fixed cam portion (241a), and the inclination size of the mountains of the first cam (244a) may be the same as or similar to the inclination size (e.g., the first inclination) of the mountains of the first fixed cam portion (241a). The above first cam (244a) can perform cam operation with the first fixed cam portion (241a) by the elastic force provided by the first cam elastic member (242a).A second shaft (232) may be inserted into the second cam (244b). The second cam (244b) may have an internal shape corresponding to the z-axis cross-sectional shape of the second shaft (232) (e.g., at least a portion of the shape is a D-cut shape) so as to rotate in response to the rotation of the second shaft (232). The second cam (244b) may include a cam pattern (or cam structure) corresponding to the second fixed cam portion (241b). As an example, the second cam (244b) may have a slope size equal to the absolute value of the slope size of the mountain of the second fixed cam portion (241b) or a slope size equal to the slope size of the mountain of the first cam (244a) (e.g., the first slope). The second cam (244b) may perform a cam operation with the second fixed cam portion (241b) by an elastic force provided by the second cam elastic member (242b). The first cam (244a) and the second cam (244b) can be pressed by the first cam elastic member (242a) and the second cam elastic member (242b) provided to implement relatively strong torque compared to the third cam (244c) and the fourth cam (244d). When the cam contact angle (e.g., the first contact angle (a1)) of the first cam structures (e.g., the first cam (244a) and the second cam (244b) and the first fixed cam portion (241a) and the second fixed cam portion (241b)) is set to 20 degrees or less, a large deviation may not occur even when the operating amount is less than 0.05 to 0.1 mm (torque reduction of 20% or less).The cam contact angle (e.g., the first contact angle (a1)) applied to the first cam structure above can serve to reduce the torque by increasing the spring compression length so that the user does not have to use a large force during the process of closing the housings due to the repulsive force (repulsive force of the flexible display 160 of FIG. 2) that increases when the foldable electronic device (100) is closed (folded) so that the user does not have to use a large force, and can serve to reduce the surface pressure to less than 20% when the foldable electronic device (100) is opened (unfolded) so as to improve the situation in which the user does not feel the sensation of trying to unfold (detent, so that the user can feel that it is open) due to the strong surface pressure. A first gear shaft (238) may be inserted into the third cam (244c). The third cam (244c) may have an internal shape corresponding to the z-axis cross-sectional shape of the first gear shaft (238) (e.g., at least a portion thereof has a D-cut shape) so as to rotate in response to the rotation of the first gear shaft (238). The third cam (244c) may include a cam pattern (or cam structure) corresponding to the third fixed cam portion (241c). For example, the third cam (244c) includes mountains and valleys having a shape opposite to (or arranged to mesh with) mountains and valleys formed in the third fixed cam portion (241c), and the inclination size of the mountains of the third cam (244c) may correspond to the inclination size (e.g., the second inclination) of the mountains of the third fixed cam portion (241c). The above third cam (244c) can perform cam operation with the third fixed cam part (241c) by the elastic force provided by the third cam elastic member (242c). A second gear shaft (239) may be inserted into the fourth cam (244d). The fourth cam (244d) may have an internal shape corresponding to the z-axis cross-sectional shape of the second gear shaft (239) (e.g., at least a portion of the shape is a D-cut shape) so as to rotate in response to the rotation of the second gear shaft (239). The fourth cam (244d) may include a cam pattern (or cam structure) corresponding to the fourth fixed cam portion (241d). As an example, the fourth cam (244d) may have a slope size equal to the absolute value of the slope size of the mountain of the fourth fixed cam portion (241d) or a slope equal to the slope of the mountain of the third cam (244c) (e.g., a second slope). The fourth cam (244d) may perform a cam operation with the fourth fixed cam portion (241d) by an elastic force provided by the fourth cam elastic member (242d). As described above, the second cam structure (e.g., the third cam (244c) and the fourth cam (244d) and the third fixed cam portion (241c) and the fourth fixed cam portion (241d)) can be configured to have a contact angle (e.g., the second contact angle (a2)) that is larger (sharply) than the contact angle (e.g., the first contact angle (a1)) of the first cam structure. According to one embodiment, in the unfolded state of the foldable electronic device (100), the contact angle (e.g., the second contact angle (a2)) of the second cam structure is set to 35 degrees or more, so that the unfolded state can be maintained and supported. As an example, by sufficiently providing a cam stroke due to a basic compression amount (or compressible amount) of a coil spring of 2.0 mm or more, the hinge structure (201) of the present disclosure can implement a detent without a large problem even when there is a rotational deviation of axes arranged on both sides with respect to the horizontal center line of the fixed bracket (213). The description of the formation of the first contact angle (a1) and the second contact angle (a2) described above and the operation state of the hinge structure (201) according to the formation can be applied identically or similarly to other hinge structures described below or the hinge structures described above. Referring to FIGS. 1 to 8, as in graphs 801 and 802, the torque change (e.g., 801a, 801b) angle due to the first cam structure (e.g., the first cam (244a) and the second cam (244b) and the first fixed cam portion (241a) and the second fixed cam portion (241b)) may have a gentler angle compared to the torque change (802a, 802b) angle due to the second cam structure (e.g., the third cam (244c) and the fourth cam (244d) and the third fixed cam portion (241c) and the fourth fixed cam portion (241d)). Accordingly, the first cam structure having a relatively gentle cam contact angle (e.g., the first contact angle (a1)) compared to the cam contact angle (e.g., the second contact angle (a2)) of the second cam structure can reduce the torque deviation by forming the gentle angle. Alternatively, as in graphs 801 and 802, the torque change (802a, 802b) due to the second cam structure (e.g., the third cam (244c) and the fourth cam (244d) and the third fixed cam portion (241c) and the fourth fixed cam portion (241d)) has a relatively steeper cam contact angle (e.g., the second contact angle (a2)) than the torque change (e.g., 801a, 801b) due to the first cam structure (e.g., the first cam (244a) and the second cam (244b) and the first fixed cam portion (241a) and the second fixed cam portion (241b)), thereby supporting the implementation of a detent during folding and unfolding operations due to steep angle changes. The torque change (801a, 801b) caused by the first and second elastic members (242a, 242b) and the first cam structure and the torque change (802a, 802b) caused by the third and fourth elastic members (242c, 242d) and the second cam structure may include a portion of the torque change while the foldable electronic device is unfolded to a certain angle (e.g., less than 180 degrees) from a fully folded state or changed from a certain angle state to a fully unfolded state (e.g., 180 degrees). As a result, as shown in graph 803 showing the final torque changes (803a, 803b) by the elastic members and the first and second cam structures, the hinge structure (201) can stably support each housing by utilizing a large torque at a bending angle greater than 0 degrees and less than 180 degrees while providing a stable detent feeling in the folded or unfolded state of the foldable electronic device (100) while utilizing the integrated form of torque changes (801a, 801b) by the gentle cam contact angle (e.g., the first contact angle (a1)) of the first cam structure and the torque changes (802a, 802b) by the steep cam contact angle (e.g., the second contact angle (a2)) of the second cam structure. As described above, the hinge structure (201) according to one embodiment is connected to the first shaft (231) and the second shaft (232), and provides a high surface pressure structure by using the first cam elastic member (242a) and the second cam elastic member (242b) including disk springs capable of generating a large surface pressure compared to a coil spring, while the cam contact angle (e.g., the first contact angle (a1)) of the first cam structure (e.g., the first cam (244a) and the second cam (244b) and the first fixed cam portion (241a) and the second fixed cam portion (241b)) can be configured to be formed gently. A hinge structure (201) according to one embodiment is connected to a first gear shaft (238) and a second gear shaft (239), and can support a stable detent function based on a coil spring having a larger basic compression amount than a disk spring and thus capable of providing a sufficient cam stroke, and a second cam structure (e.g., a third cam (244c) and a fourth cam (244d) and a third fixed cam portion (241c) and a fourth fixed cam portion (241d)) having a cam contact angle (e.g., a second contact angle (a2)) formed more sharply than the first cam structure. According to one embodiment, the curvature of the curve formed in the third cam (244c) and the fourth cam (244d) and the third fixed cam portion (241c) and the fourth fixed cam portion (241d) is formed to be greater than the curvature of the curve formed in the first cam (244a) and the second cam (244b) and the first fixed cam portion (241a) and the second fixed cam portion (241b), so that the contact angle of the second cam structure (e.g., the second contact angle (a2)) can be formed to be greater than the contact angle of the first cam structure (e.g., the first contact angle (a1)). This hinge structure (201) provides strong torque through the first and second elastic members (242a, 242b) and the first cam structure, and provides a stable detent function through the third and fourth elastic members (242c, 242d) and the second cam structure, thereby enabling application of a cam profile (or shape) suitable for implementing each function, and enabling the integrated operation of the torques of each cam structure to offset the shortcomings of each cam structure. As described above, the first type elastic member in the form of a disc spring (e.g., the first cam elastic member (242a) and the second cam elastic member (242b) providing an elastic force of a first magnitude) can provide an elastic force (or a compressive force) of a different magnitude from the second type coil spring type elastic member (e.g., the third cam elastic member (242c) and the third cam elastic member (242c) providing an elastic force of a second magnitude). As an example, a first magnitude of elastic force provided by the first type elastic members (e.g., the first and second elastic members (242a, 242b)) to the first cam structure (e.g., the first fixed cam portion (241a) and the second fixed cam portion (241b), the first cam (244a) and the second cam (244b)) may be greater than a second magnitude of elastic force provided by the second type elastic members (the third and fourth elastic members (242c, 242d)) to the second cam structure (e.g., the third fixed cam portion (241c) and the fourth fixed cam portion (241d), the third cam (244c) and the fourth cam (244d)). Depending on the folded state, the unfolded state, or the mounting state at a specified angle (e.g., the flex mode state, the detent mode) of the hinge structure (201), the contact angle state (e.g., the first contact angle (a1)) of the first cam structure and the contact angle state (e.g., the second contact angle (a2)) of the second cam structure are formed differently, so that the contribution (or the magnitude of the force, the fixing force that allows the foldable electronic device (100) to maintain the specific mounting state, the resisting force that prevents the foldable electronic device (100) from changing the angle in the specific mounting state) of the first type elastic members and the second type elastic members to the specific state may be different. When the foldable electronic device (100) is in the flex mode state, at least one of the first type elastic member that compresses the first cam structure and the second type elastic member that compresses the second cam structure may have a maximum compression state (a state in which there is no additional compression or a state in which there is no additional deformation). According to one embodiment, when the foldable electronic device (100) is folded at a certain angle, the first and second elastic members (242a, 242b) in the form of disk springs provide an elastic force of a first magnitude to the first cam structure (e.g., the first cam (244a) and the second cam (244b), the first fixed cam portion (241a) and the second fixed cam portion (241b)), so that the hinge structure (201) can provide a force to maintain the folded state of the foldable electronic device (100) at a certain angle. Alternatively, when the foldable electronic device (100) is folded at a certain angle, the elastic members in the form of disk springs (e.g., the first cam elastic member (242a) and the second cam elastic member (242b)) can provide a force to prevent the folded angle of the foldable electronic device (100) from changing. The above-described specific angle may be an angle in the flex mode state, for example, an angle less than 180 degrees and greater than 0 degrees, or an angle less than 170 degrees (or 160 degrees) and greater than 10 degrees (or 20 degrees). Here, the specific angles, such as 180 degrees, 170 degrees, 160 degrees, 20 degrees, 10 degrees, and 0 degrees, are examples and may vary depending on design changes of the foldable electronic device. As an example, referring to FIG. 7, when the foldable electronic device (100) is in a folded state at a specified angle (e.g., a state in which the angle between the first housing (110) and the second housing (120) is less than 180 degrees and greater than 0 degrees, or during folding, or during a flex mode, for example, while the specified folding angle or the specified opening angle of the foldable electronic device (100) forms a range between 10 degrees and 160 degrees), the hinge structure (201) may have a state in which the upper end (flat portion or portion having a constant slope) of the first fixed cam portion (241a) (or the second fixed cam portion (241b)) and the upper end of the first cam (244a) (or the second cam (244b)) are in contact. In the folded state at the above-mentioned specified angle (or in the operational state where the foldable electronic device (100) is folded or unfolded at a certain angle), a high surface pressure can be formed by the first cam elastic member (242a) (or the second cam elastic member (242b)) that provides greater elasticity than the third cam elastic member (242c) (or the fourth cam elastic member (242d)). The high surface pressure by the first cam structure can contribute more significantly to maintaining the foldable electronic device (100) from changing from a specific angle (e.g., an angle between the first housing (110) and the second housing (120) less than 180 degrees and greater than 0 degrees) to another angle than the second cam structure. For example, as illustrated in FIG. 7, when the foldable electronic device (100) is in an unfolded state (e.g., a state in which the angle between the first housing (110) and the second housing (120) is 180 degrees) (or while the unfolded state is maintained), the hinge structure (201) has a first contact angle (a1) (or a contact inclination angle) (or a first contact angle (a1) of the first cam structure) in a state in which the first fixed cam portion (241a) and the first cam (244a) are in contact and a second fixed cam portion (241b) and the second cam (244b) are in contact, and a second contact angle (a2) (or a contact inclination angle) (or a second contact angle (a1) of the second cam structure) in a state in which the third fixed cam portion (241c) and the third cam (244c) are in contact and a fourth fixed cam portion (241d) and the fourth cam (244d) are in contact. The hinge structure (201) may have a state in which the second contact angle (a2) of the second cam structure is larger than the first contact angle (a1) of the first cam structure. In this state, even if the third cam elastic member (242c) and the fourth cam elastic member (242d) have smaller elastic forces than the first cam elastic member (242a) and the second cam elastic member (242b), the second cam structure may contribute more to maintaining the unfolded state of the hinge structure (201) than the first cam structure, depending on the inclination of the second contact angle (a2) described above. According to one embodiment, when the foldable electronic device (100) is in a fully folded state (e.g., a state in which the angle between the first housing (110) and the second housing (120) is 0 degrees, or a state in which the two housings are aligned in an 11-degree angle) (or while the folded state is maintained), the second contact angle (a2) of the second cam structure of the hinge structure (201) may have a greater inclination than the first contact angle (a1) of the first cam structure. Accordingly, when the foldable electronic device (100) is in a fully folded state, the third cam elastic member (242c) and the fourth cam elastic member (242d) and the second cam structure may contribute more to maintaining the hinge structure (201) in the folded state than the first cam elastic member (242a) and the second cam elastic member (242b) and the first cam structure. Alternatively, when the foldable electronic device (100) is in a fully folded state, the third cam elastic member (242c) and the fourth cam elastic member (242d) and the second cam structure may contribute more to offsetting the repulsive force of the display (160) that is about to unfold compared to the first cam elastic member (242a) and the second cam elastic member (242b) and the first cam structure. As described above, when the foldable electronic device (100) changes from a folded state to an unfolded state (or from an unfolded state to a folded state), the first cam structure pressed by the first type elastic members (e.g., the first cam elastic member (242a) and the second cam elastic member (242b)) may have a first cam stroke and a contact angle of a cam pattern of a first size (e.g., the first contact angle (a1)), and the second cam structure pressed by the second type elastic members (e.g., the third cam elastic member (242c) and the fourth cam elastic member (242d)) may have a second cam stroke and a contact angle of a cam pattern of a second size (e.g., the second contact angle (a2)). The first cam stroke and the first contact angle (a1) of the first cam structure, and the second cam stroke and the second contact angle (a2) of the second cam structure can be determined according to various mounting angle states, unfolded states, and folded states of the foldable electronic device (100). According to one embodiment, while the foldable electronic device (100) maintains the flex mode, the first type elastic members (the first and second elastic members (242a, 242b)) and the first cam structure may contribute more (have a greater contributing force) to maintaining the flex mode of the foldable electronic device (100) based on a greater elastic force than the second type elastic members (the third and fourth elastic members (242c, 242d)) and the second cam structure. In the flex mode state, the first contact angle (a1) of the first cam structure and the second contact angle (a2) of the second cam structure may be the same (e.g., 0 degree or horizontal), and the first cam stroke and the second cam stroke may have the same state. According to one embodiment, when the shapes of the upper portions of the cams of the first cam structure and the second cam structure are both configured to be flat, in the flex mode state, the first contact angle (a1) of the first cam structure and the second contact angle (a2) of the second cam structure may be 0 or a horizontal state. When the shapes of the upper portions of the cams of the first cam structure and the second cam structure are formed to have an inclination (or gradient) greater than 0, in the flex mode state, the first contact angle (a1) of the first cam structure and the second contact angle (a2) of the second cam structure may have a state other than 0 or a horizontal state. Alternatively, when the upper portion of the cam of the first cam structure is formed to be flat and the upper portion of the cam of the second cam structure is formed to have an inclination (or gradient) greater than 0, in the flex mode state, the first cam structure may have a horizontal contact state between the cam and the fixed cam portion, while the second cam structure may have a contact state between the cam and the fixed cam portion at an inclination greater than 0 degrees. The slope of the top of the cam may have a smaller value than the slope of the side slope connected to the top of the cam. Alternatively, the top of the cam may be formed more gently than the cam slope. According to one embodiment, while the foldable electronic device (100) maintains a fully folded state (close mode) or a fully unfolded state (open mode), a second cam structure having a larger contact angle (e.g., the second contact angle (a2)) than a contact angle (e.g., the first contact angle (a1)) of the first cam structure may contribute more to maintaining the fully folded state or the fully unfolded state than the first cam structure. For example, when the display (160) maintains a folded state for a certain period of time or longer, a folding characteristic (or force) may occur when the display (160) is fully unfolded, and the large contact angle (e.g., the second contact angle (a2)) of the second cam structure may contribute more to offsetting the characteristic of the display (160) to fold again than the first cam structure. In a fully folded state or a fully unfolded state, the first cam stroke of the first cam structure may be shorter than the second cam stroke of the second cam structure, and the first contact angle may be formed smaller than the second contact angle. Alternatively, the second cam stroke of the second cam structure may be longer than the first cam stroke of the first cam structure, and the second contact angle (a2) may be formed larger than the first contact angle (a2). According to one embodiment, while the foldable electronic device (100) in a predetermined folding angle state (or a designated folding angle state, for example, a state opened at an angle of between 160 and 10 degrees) is changed to a fully folded state, as the contact angle of the first cam structure (e.g., the first contact angle a1) deviates from 0 degree (or a horizontal state) and has a non-zero inclination just before being fully folded, the torque provided by the first type elastic members and the first cam structure decreases, so that the user can fold the foldable electronic device (100) with less force. Additionally or alternatively, magnetic members provided in the foldable electronic device may contribute to the complete folding of the foldable electronic device (100). According to one embodiment, while the foldable electronic device (100) in a predetermined angle state is changed to a fully unfolded state, as the contact angle of the first cam structure (e.g., the first contact angle (a1)) deviates from 0 degrees (or a horizontal state) and has a non-zero inclination right before being fully unfolded, the torque provided by the first type elastic members and the first cam structure decreases, so that the user can unfold the foldable electronic device (100) with a smaller force. Thereafter, when the contact angle of the second cam structure (e.g., the second contact angle (a2)) deviates from 0 degrees (or a horizontal state) and has a non-zero inclination, the user can fully unfold the foldable electronic device (100) with a smaller force as the second type elastic members press the second cam structure having the non-zero inclination of the contact angle (e.g., the second contact angle (a2)). FIG. 9 is a drawing illustrating another example of a cam member and cams in a hinge structure according to one embodiment. Fig. 10 is a drawing showing the change in torque during the unfolding and folding operation of the hinge structure exemplified in Fig. 9. Referring to FIGS. 1 to 9, a hinge structure (202) according to one embodiment comprises a fixed bracket (213), a first arm member (221), a second arm member (222), a first shaft (231), a second shaft (232), a first gear shaft (238), a second gear shaft (239), a deformation cam member (241_ch1), deformation cams (244e, 244f, 244c, 244d), cam elastic members (242a, 242b, 242c, 242d), a plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4), a plurality of support members (248a, 248b, 248c), a shaft fixing part (243), a fixing It may include nuts (249d1, 249d2). Additionally, the hinge structure (202) may further include a first rotational member (e.g., the first rotational member 211 of FIG. 3) and a second rotational member (e.g., the second rotational member 212 of FIG. 3) that are connected to the fixed bracket (213), and may further include a first link member (e.g., the first link member 215 of FIG. 3) to which the first rotational member is connected, a second link member (e.g., the second link member 216 of FIG. 3) to which the second rotational member is connected, a third link member (e.g., the third link member 223 of FIG. 3) to which the first arm member (221) is connected, and a fourth link member (e.g., the fourth link member 224 of FIG. 3) to which the second arm member (222) is connected. Among the components of the hinge structure (202) described above, at least some of the remaining components, excluding the deformation cam member (241_ch1) and the deformation cams (244e, 244f, 244c, 244d), may perform substantially the same configuration and role as the components described above in FIGS. 3 to 7. Accordingly, the components other than the deformation cam member (241_ch1) and the deformation cams (244e, 244f, 244c, 244d) will be replaced with the contents described above. The above-described deformation cam member (241_ch1) may include a first deformation cam portion (241e), a second deformation cam portion (241f), a third fixed cam portion (241c), and a fourth fixed cam portion (241d). Here, the third fixed cam portion (241c) and the fourth fixed cam portion (241d) may have the same configuration as the third fixed cam portion (241c) and the fourth fixed cam portion (241d) described above with reference to FIGS. 3 to 7. The interior of the first deformation cam portion (241e) may be formed with a through hole into which the first shaft (231) may be inserted. The first deformation cam portion (241e) may have a through hole whose z-axis cross section is circular so as to maintain a fixed state even when the first shaft (231) rotates. One side (e.g., a side facing the y-axis direction) of the first deformation cam portion (241e) may be formed flat, and the other side (e.g., a direction facing the -y-axis direction or the third friction member (249b1)) of the first deformation cam portion (241e) may be formed flat or may have a shape corresponding to the shape of the third friction member (249b1). The second deformation cam portion (241f) may have the same size and shape as the first deformation cam portion (241e). The second deformation cam portion (241f) may be arranged symmetrically with respect to the horizontal center line of the fixed bracket (213) with respect to the first deformation cam portion (241e). As an example, the interior of the second deformation cam portion (241f) may have a through hole formed into which the second shaft (232) may be inserted, and at least a portion of the z-axis cross section may include a D-cut shape (or an angled shape). One side (e.g., the side facing the y-axis direction) of the second deformation cam portion (241f) is formed flat, similar to the first deformation cam portion (241e), and the other side (e.g., the direction facing the -y-axis direction or the fourth friction member (249b2)) of the second deformation cam portion (241f) may be formed flat or may have a shape corresponding to the shape of the fourth friction member (249b2). The above-described deformation cams (244e, 244f, 244c, 244d) may include a first deformation cam (244e), a second deformation cam (244f), a third cam (244c), and a fourth cam (244d). The third cam (244c) and the fourth cam (244d) may have the same or similar structure and size as the third cam (244c) and the fourth cam (244d) described above with reference to FIGS. 3 to 7. Accordingly, the description of the third cam (244c) and the fourth cam (244d) may be replaced with the description described above. The first deformation cam (244e) may include a through hole having an angled shape at least in part of a z-axis cross section so that a first shaft (231) is inserted therein and rotates in response to the rotation of the first shaft (231). The first deformation cam (244e) may be in contact with the first deformation cam portion (241e) by an elastic force provided by the first cam elastic member (242a). The first deformation cam (244e) may have a side facing the first deformation cam portion (241e) formed to be flat. Accordingly, the first deformation cam (244e) may be in contact with the first deformation cam portion (241e) in a flat state. Alternatively, the contact angle between the first deformation cam (244e) and the first deformation cam portion (241e) may correspond to 0 degrees. The second deformation cam (244f) may include a through hole having an angled shape at least in part of the z-axis cross section so that a second shaft (232) is inserted therein and rotates in response to the rotation of the second shaft (232). The second deformation cam (244f) may have the same size and structure as the first deformation cam (244e) described above. The second deformation cam (244f) may be arranged symmetrically with respect to the first deformation cam (244e), for example, with respect to the horizontal center line of the fixed bracket (213). The second deformation cam (244f) may be in contact with the second deformation cam portion (241f) by the elastic force provided by the second cam elastic member (242b), and the contact angle may be 0 degrees or may be in horizontal contact. Referring to FIG. 10, as in the 1001 graph, the torque by the second cam structure (e.g., the third cam (244c) and the third fixed cam portion (241c) and the fourth cam (244d) and the fourth fixed cam portion (241d)) may be maintained constant after the torque by the cam operation increases when changing from a folded state (e.g., a state in which the angle between the housings is 0 degrees) to a bent state (a state in which the angle between the housings is greater than 0 degrees but less than 180 degrees), and may decrease when changing from a bent state to an unfolded state (e.g., a state in which the angle between the housings is 180 degrees). This change in torque by the second cam structure may be the same as the 801 graph described above in FIG. 8. As in the graph of Fig. 1002, the torque by the first deformation cam structure (e.g., the first deformation cam (244e) and the first deformation cam portion (241e), the second deformation cam (244f) and the second deformation cam portion (241f)) can be maintained constant as shown, as the contact angle of the cams is maintained constant. Accordingly, as in the 1003 graph, the integrated torque of the torque change by the first modified cam structure and the torque change by the second cam structure can be expressed as a value in which the torque change provided by the second cam structure is added to the constant torque provided by the first modified cam structure. As described above, if flex support is required for almost the entire range from 0 to 180 degrees, there is no need to provide torque change by a separate first deformation cam structure, so the first deformation cam structure, in which torque is provided by the disk springs, is responsible for only a surface pressure greater than a certain size, thereby providing a constant surface pressure that is not changed by the cam operation, so that the hinge structure (202) can implement an unfolding or closing (or folding) detent using the second cam structure. FIG. 11 is a drawing showing an example of a hinge structure in which the positions of the cam member and the cams are changed according to one embodiment. Referring to FIGS. 1 to 11, a hinge structure (203) according to one embodiment includes a fixed bracket (213), a first deformation arm member (221_ch1), a second deformation arm member (222_ch1), a plurality of friction members (249_ch1, 249_ch2, ​​249_ch3, 249_ch4), a plurality of support members (248a, 248b), a shaft fixing member (243), fixed nuts (249d1, 249d2), a first cam elastic member (242a), a second cam elastic member (242b), a third deformation cam elastic member (242e), a fourth deformation cam elastic member (242f), a first cam member (241_ch2), a second cam member (246_ch), a first main gear (233a) (or a first deformation main gear), a second main gear (233b) (or a second deformation main gear), It may include a first gear (238a) and a second gear (239a). Additionally, the hinge structure (203) may further include a first shaft (the first shaft 231 of FIG. 3) on which the first main gear (233a) is formed (or fastened), a second shaft (the second shaft 232 of FIG. 3) on which the second main gear (233b) is formed (or fastened), a first gear shaft (238) on which the first gear (238a) is formed (or fastened), and a second gear shaft (239) on which the first gear (238a) is formed (or fastened). In addition, the hinge structure (203) may further include a third link member (the third link member 223 of FIG. 3) to which the first deformation arm member (221_ch1) is fastened, a fourth link member (the fourth link member 224 of FIG. 3) to which the second deformation arm member (222_ch1) is fastened, and may further include a first rotation member that rotates in response to the rotation of the first deformation arm member (221_ch1), a first link member to which the first rotation member is coupled, a second rotation member that rotates in response to the rotation of the second deformation arm member (222_ch1), and a second link member to which the second rotation member is coupled. The first deformation arm member (221_ch1) may be arranged between one side (e.g., the first fixed cam portion (241a)) of the first cam member (241_ch2) and one side wing of the second cam member (246_ch). The first deformation arm member (221_ch1) may include a first arm cam (221_cam) arranged in a direction toward the first cam member (241_ch2). A first shaft (e.g., the first shaft 231 of FIG. 3) is disposed penetratingly inside the first deformation arm member (221_ch1) and may rotate in one direction (e.g., clockwise or counterclockwise) in response to the rotation of the first shaft. In this process, the first deformation arm member (221_ch1) can perform a cam operation by the elasticity of the first cam elastic member (242a) that provides elasticity to the first fixed cam portion (241a) of the first cam member (241_ch2). The second deformation arm member (222_ch1) may be arranged between the other side (e.g., the second fixed cam portion (241b)) of the first cam member (241_ch2) and the other side wing of the second cam member (246_ch). The second deformation arm member (222_ch1) may include a second arm cam (222_cam) arranged in a direction toward the second fixed cam portion (241b) of the first cam member (241_ch2). A second shaft (e.g., the second shaft 232 of FIG. 3) is disposed penetratingly inside the second deformation arm member (222_ch1) and may rotate in one direction (e.g., counterclockwise or clockwise) in response to the rotation of the second shaft. In this process, the second deformation arm member (222_ch1) can perform a cam operation by the elasticity of the second cam elastic member (242b) that provides elasticity to the second fixed cam portion (241b). The above first cam member (241_ch2) may include a first fixed cam portion (241a) into which a first shaft (e.g., the first shaft 231 of FIG. 3) is inserted, a second fixed cam portion (241b) into which a second shaft (e.g., the second shaft 232 of FIG. 3) is inserted, and a cam connection portion (241_co) connecting the first fixed cam portion (241a) and the second fixed cam portion (241b). The cam connection portion (241_co) may include grooves that support one side of the first gear shaft (238) and the second gear shaft (239). The second cam member (246_ch) may include a first wing (236_w1) into which a first shaft (e.g., the first shaft 231 of FIG. 3) is inserted, a second wing (236_w2) into which a second shaft (e.g., the second shaft 232 of FIG. 3) is inserted, a third fixed cam portion (236_cam1) and a fourth fixed cam portion (236_cam2) arranged between the first wing (236_w1) and the second wing (236_w2). The first wing (236_w1), the second wing (236_w2), the third fixed cam portion (236_cam1), and the fourth fixed cam portion (236_cam2) may be connected to each other. The above first wing (236_w1) and second wing (236_w2) can serve to support friction members (e.g., 249_ch1, 249ch_2). At least a part of the first gear shaft (238) can be disposed penetratingly inside the third fixed cam portion (236_cam1), and at least a part of the second gear shaft (239) can be disposed penetratingly inside the fourth fixed cam portion (236_cam2). A third deformation cam elastic member (242e) and a third cam (244g) may be fastened to the first gear shaft (238). The third cam (244g) may be pressed toward the third fixed cam portion (236_cam1) by the elastic force of the third deformation cam elastic member (242e). A central side of a plurality of support members (248a, 248b) may be inserted into the first gear shaft (238). A fourth deformation cam elastic member (242f) and a fourth cam (244h) may be fastened to the second gear shaft (239). The fourth cam (244h) may be pressed toward the fourth fixed cam portion (236_cam2) by the elastic force of the fourth deformation cam elastic member (242f). The central other side of a plurality of support members (248a, 248b) may be inserted into the first gear shaft (238). As described above, the hinge structure (203) can be configured such that the first cam elastic member (242a) and the second cam elastic member (242b) of the disk spring type press the first cam member (241_ch2) of the fixed type, and the female cams (221_cam, 221_cam) formed on the deformable female members (221_ch1, 222_ch2) and the first cam member (241_ch2) can perform a cam operation. The above-described hinge structure (203) comprises a first shaft (e.g., the first shaft 231 of FIG. 3) penetrating the first cam elastic member (242a), the first cam member (241_ch2), and the first female cam (221_cam), and a second shaft (e.g., the second shaft 232 of FIG. 3) penetrating the second cam elastic member (242b), the second cam member (246_ch), and the second female cam (222_cam), to which a plurality of friction members (249_ch1, 249_ch2, ​​249_ch3, 249_ch4) and a plurality of support members (248a, 248b) are fastened, so as to provide a strong torque due to a high surface pressure. In addition, the third deformation cam elastic member (242e) and the fourth deformation cam elastic member (242f) of the coil spring type can be arranged at other positions of the hinge structure (203) apart from the structure adjacent to the first cam elastic member (242a) and the second cam elastic member (242b) described in FIG. 3. FIG. 12 is a drawing showing an example of a hinge structure in which the positions of cams are changed according to one embodiment. Referring to FIGS. 1 to 12, a hinge structure (204) according to an embodiment includes a third deformation arm member (221_ch2) in which a first arm cam (221_cam) (or a first cam of a first deformation arm member) is arranged, a third link member (223), a fourth deformation arm member (222_ch2) in which a second arm cam (222_cam) is arranged, a fourth link member (224), a first gear (238a) and a third deformation cam (221_cam2), a second gear (239a) and a fourth deformation cam (222_cam2), a plurality of friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2), a plurality of support members (248a, 248b), a gear bracket (236), a first cam member (241_ch4), and a second cam. The hinge structure (204) may include a fixed bracket (e.g., fixed bracket 213 of FIG. 3), a first rotational member (e.g., first rotational member 211 of FIG. 3), a second rotational member (e.g., second rotational member 212 of FIG. 3), a first link member (e.g., first link member 215 of FIG. 3), and a second link member (e.g., second link member 216 of FIG. 3), as described above with reference to FIG. 3. The first female cam (221_cam) may be arranged on one side of the third deformable female member (221_ch2) (e.g., in the direction facing the y-axis, or in the direction in which the first cam elastic member (242a) is arranged, or in the direction in which the first fixed cam portion (241_31) of the first cam member (241_ch4) is arranged). The first female cam (221_cam) may have a first shaft (231) penetratingly arranged at the center thereof, and may include a cam pattern (e.g., a mountain and a valley or a repeating pattern thereof) corresponding to the first fixed cam portion (241_31). As various embodiments, as described above with reference to FIG. 9, the first female cam (221_cam) may have a flat structure without separate mountains and valleys so that the contact angle is formed to be 0 degrees. When the side (e.g., the outer surface in the direction in which the first cam elastic member (242a) faces) of the first cam (221_cam) formed integrally with the third modified arm member (221_ch2) is formed flat, the first fixed cam portion (241_31) may also be formed flat correspondingly. Alternatively, the first fixed cam portion (241_31) may have a cam structure including mountains and valleys. The first main gear (233a) (or the first modified main gear) integrated with the third modified arm member (221_ch2) may be gear-coupled with the first gear (238a) as described above with reference to FIGS. 3 to 6. The inner side of the third deformed arm member (221_ch2) on which the first main gear (233a) is formed has a through hole formed that penetrates in the -y-axis or y-axis direction (or the direction in which the first cam elastic member (242a) is arranged), and a first shaft (231) can be arranged in at least a portion of the inside of the through hole.At least a portion of the inner space (or the through hole) of the third deformation arm member (221_ch2) may have a shape (e.g., a space forming at least a portion of an angular shape or a D-cut) corresponding to a shape of a z-axis cross-section of the first shaft (231) (e.g., a shape including at least a portion of an angular shape or a D-cut) so as to rotate in response to the rotation of the first shaft (231) (or so as to rotate the first shaft (231) as the third deformation arm member (221_ch2) rotates). The inner space of the first arm cam (221_cam) may also have a space corresponding to a shape of a z-axis cross-section of the first shaft (231) (e.g., at least a portion of the space forming an angular shape) arranged in the inner space so as to rotate in response to the rotation of the first shaft (231). The second arm cam (222_cam) may be arranged on one side of the fourth deformed arm member (222_ch2) (e.g., in the direction toward the y-axis, in the direction in which the second cam elastic member (242b) is arranged, or in the direction in which the second fixed cam portion (241_32) of the first cam member (241_ch4) is arranged). As an example, the second arm cam (222_cam) may be formed integrally with the fourth deformed arm member (222_ch2). The second arm cam (222_cam) may be formed adjacent to the second main gear (233b) (or the second deformed main gear). Alternatively, the second main gear (233b) may be formed to be bent in the x-axis direction of the fourth deformed arm member (222_ch2), and the second arm cam (222_cam) may be arranged to face the y-axis direction. The inner space of the second arm cam (222_cam) and the inner space of the fourth deformed arm member (222_ch2) wrapped by the second main gear (233b) may be connected. A second shaft (232) may be inserted into the connected inner spaces. While the second arm cam (222_cam) and the second main gear (233b) rotate, at least some of the inner spaces are formed angularly (to include at least one corner) so that the second shaft (232) rotates, and the inner spaces including at least one corner may correspond to the z-axis cross-sectional shape of the second shaft (232). For example, the z-axis cross-section of the second shaft (232) may include at least one corner. The second female cam (222_cam) and the second main gear (233b) described above may have the same or similar structure and size as the first female cam (221_cam) and the first main gear (233a) integrated into the third modified female member (221_ch2) described above.The second female cam (222_cam) and the second main gear (233b) may be arranged symmetrically on both sides (e.g., -x-axis and x-axis) with respect to the center line crossing the middle of the first deformation gear shaft (238_ch) and the second deformation gear shaft (239_ch) with respect to the first female cam (221_cam) and the first main gear (233a). At least one of the first gear (238a) and the third deformation cam (221_cam2) may be formed integrally or fixedly on the first deformation gear shaft (238_ch). For example, the first gear (238a) and the third deformation cam (221_cam2) may be formed integrally to surround an outer surface of the first deformation gear shaft (238_ch). The third deformation cam (221_cam2) may be arranged (or formed) on a side (e.g., in the direction toward the y-axis) of the first gear (238a) and may be arranged to face the third fixed cam portion (241_33) of the second cam member (241_ch5). As another example, the first gear (238a) may be formed integrally with the first deformation gear shaft (238_ch), and the third deformation cam (221_cam2) may be disposed between the first gear (238a) and the third fixed cam portion (241_33) with the first deformation gear shaft (238_ch) inserted inside. At least a portion of the internal space of the third deformation cam (221_cam2) may be formed angularly (or may include at least one corner) so as to be able to rotate in response to the rotation of the first deformation gear shaft (238_ch), and at least a portion of the z-axis cross section of the first deformation gear shaft (238_ch) that is seated in the internal space of the third deformation cam (221_cam2) may be formed angularly (or may be formed in a shape identical to or similar to the shape of the internal space of the third deformation cam (221_cam2)). As a variety of embodiments, the first gear (238a) may also be provided in a form separate from the first deformation gear shaft (238_ch), and the first deformation gear shaft (238_ch) may be inserted into an internal space of the first gear (238a) (e.g., a space forming a through hole penetrating from the y-axis to the -y-axis). The internal space of the first gear (238a) includes at least one edge, and this shape may correspond to the z-axis cross section of the first deformation gear shaft (238_ch). The second modified gear shaft (239_ch) may have at least one of the same or similar sizes and structures as the first modified gear shaft (238_ch) described above. For example, the second modified gear shaft (239_ch) includes an integrated second gear (239a) and an integrated fourth modified cam (222_cam2), and the second gear (239a) and the fourth modified cam (222_cam2) may rotate in response to the rotation of the first modified gear shaft (238_ch). The fourth modified cam (222_cam2) may be arranged to face the fourth fixed cam portion (241_34) of the second cam member (241_ch5). The above gear bracket (236) includes holes through which one side of the first and second shafts (231, 232) and the first and second deformation gear shafts (238_ch, 239_ch) can be positioned through, and may include stopper structures to prevent the third deformation arm member (221_ch2) and the fourth deformation arm member (222_ch2) from rotating beyond a certain angle. The first cam member (241_ch4) is arranged between the first cam elastic member (242a) and the second cam elastic member (242b) and the first female cam (221_cam) and the second female cam (222_cam), and the first fixed cam portion (241_31) and the second fixed cam portion (241_32) included in the first cam member (241_ch4) can be connected to and fixed to each other. In this regard, the first cam member (241_ch4) may further include a first connecting structure (Cam_co1) (or connecting portion) connecting the first fixed cam portion (241_31) and the second fixed cam portion (241_32). The first connecting structure (cam_co1) is formed with two holes penetrating in the y-axis and -y-axis directions, and a third deformation cam (221_cam2) and a fourth deformation cam (222_cam2) can be positioned penetrating through the two holes. The first connecting structure (cam_co1) can be formed to fix the first fixed cam portion (241_31) and the second fixed cam portion (241_32), while allowing the third deformation cam (221_cam2) and the fourth deformation cam (222_cam2) to rotate. The first fixed cam portion (241_31) and the second fixed cam portion (241_32) have the same shape and size (or the same elastic force), and can be combined with the first female cam (221_cam) and the second female cam (222_cam) by being pressed by the elastic force from the first cam elastic member (242a) and the second cam elastic member (242b), respectively. A first shaft (231) and a second shaft (232) can be inserted into the first fixed cam portion (241_31) and the second fixed cam portion (241_32). The inner side of the first fixed cam portion (241_31) and the second fixed cam portion (241_32) may include a space (or through hole) having a size greater than the size of the z-axis cross section of the first shaft (231) and the second shaft (232) so that the first shaft (231) and the second shaft (232) can rotate after insertion. The second cam member (241_ch5) is disposed between the third cam elastic member (242c) and the fourth cam elastic member (242d) and the third deformation cam (221_cam2) and the fourth deformation cam (222_cam2), and may include the third fixed cam portion (241_33) and the fourth fixed cam portion (241_34), and the second connecting structure (cam_co2). The third fixed cam portion (241_33) and the fourth fixed cam portion (241_34) have the same shape and size (or the same elastic force), and may be pressed by the elastic force from the third cam elastic member (242c) and the fourth cam elastic member (242d) to cam-couple with the third deformation cam (221_cam2) and the fourth deformation cam (222_cam2). A space (e.g., a through hole) may be formed inside the third fixed cam portion (241_33) and the fourth fixed cam portion (241_34) into which the first modified gear shaft (238_ch) and the second modified gear shaft (239_ch) are inserted and then rotated. The second connecting structure (cam_co2) connects the third fixed cam portion (241_33) and the fourth fixed cam portion (241_34), thereby fixing the third fixed cam portion (241_33) and the fourth fixed cam portion (241_34) so ​​as not to rotate. The at least one of the friction members (at least one of 249a1, 249a2, 249b1, 249b2, 249c1, 249c2) and the at least one of the support members (at least one of 248a, 248b) may be arranged between the cam elastic members (242a, 242b, 242c, 242d) and the shaft fixing part (243). The role of the at least one of the friction members (at least one of 249a1, 249a2, 249b1, 249b2, 249c1, 249c2) and the at least one of the support members (at least one of 248a, 248b) may be to convert the elastic force provided by the cam elastic members (242a, 242b, 242c, 242d) into torque (or frictional force). The positions at which the at least one of the friction members (at least one of 249a1, 249a2, 249b1, 249b2, 249c1, 249c2) and the at least one of the support members (at least one of 248a, 248b) are arranged can be changed to various positions where the elastic force of the cam elastic members (242a, 242b, 242c, 242d) can be transmitted. According to one embodiment, the first arm cam (221_cam) may not be formed on the arm member (or the first modified arm member, the first arm member) but may be formed integrally on one side of the first main gear (233a). The second arm cam (222_cam) may not be formed on the arm member (or the second modified arm member, the second arm member) but may be formed integrally on one side of the second main gear (233b). As shown in FIGS. 3 to 9 above, the first main gear (233a) and the second main gear (233b) may be formed integrally on the arm member, but as described in FIG. 11, they may be provided in a form separate from the arm members and disposed on or integrally formed on the first shaft (231) and the second shaft (232). Accordingly, the first female cam (221_cam) may be formed integrally with the first shaft (231) or integrally with the side of the first main gear (233a) integrated with the first shaft (231). The second female cam (222_cam) may be formed integrally with the second shaft (232) or integrally with the side of the second main gear (233b) integrated with the second shaft (232). As described above, the hinge structure (204) may include a form in which the positions of the deformation cams (241_31, 241_32, 241_33, 241_34) are integrated into the structure in which the gears are formed. Additionally or alternatively, in FIG. 12, a structure is exemplified in which the first cam member (241_ch4) is arranged to face the first cam elastic member (242a) and the second cam elastic member (242b) and is arranged to directly receive elastic force from the first cam elastic member (242a) and the second cam elastic member (242b), but the present disclosure is not limited thereto. For example, in the third modified arm member (221_ch2), the first arm cam (221_cam) may be formed on a side opposite to one side of the third modified arm member (221_ch2) as illustrated (e.g., a side in the -y-axis direction), and similarly, in the fourth modified arm member (222_ch2), the second arm cam (222_cam) may be formed on a side opposite to one side of the fourth modified arm member (222_ch2) as illustrated (e.g., a side in the -y-axis direction). The first cam member (241_ch4) may be correspondingly arranged between the third modified arm member (221_ch2) and the fourth modified arm member (222_ch2) and the gear bracket (236). According to one embodiment, the positions of the second cam member (241_ch5) and the third deformation cam (221_cam2) and the fourth deformation cam (222_cam2) can also be moved between the first gear (238a) and the second gear (239a) and the gear bracket (236). The hinge structure having the above-described structure allows the first cam elastic member (242a) and the second cam elastic member (242b) to directly provide elastic force to the third deformation arm member (221_ch2) and the fourth deformation arm member (222_ch2), and the third cam elastic member (242c) and the fourth cam elastic member (242d) to directly provide elastic force to the first gear (238a) and the second gear (239a). The hinge structure of the present invention described above uses a disk spring capable of implementing a high force exceeding a certain standard in relation to high torque implementation in the cam structure of the first incline, while the coil spring related to detent implementation can be independently arranged in the cam structure of the second incline. For example, the hinge structure of the present invention operates a disk spring for strong spring force to provide a strong surface pressure structure, while arranging a cam structure (e.g., a fixed cam portion and cam patterns) having a gentle incline of 20 degrees or less to implement high (or higher than a standard value) torque, and when the foldable electronic device is unfolded or folded (Open or Closed), the basic torque (torque provided by the disk spring provided when the foldable electronic device (100) is in a folded or unfolded state) is reduced, thereby making it easier to fold the foldable electronic device or increasing the experience of unfolding detent. In addition, the hinge structure of the present invention uses a coil spring having a basic compression amount of an elastic body greater than a certain standard value, and configures a cam structure (e.g., at least one fixed cam portion and at least one cam having a contact angle of 35 degrees or greater in a rotation section where a detent of the foldable electronic device (100) is required, thereby supporting implementation of a detent force in the unfolded and folded states of the foldable electronic device (100). FIG. 13 is a drawing showing an example of a cam pattern according to one embodiment. Referring to FIGS. 1 to 13, a cam pattern according to an embodiment may include an upper cam pattern (244_cam) and a lower cam pattern (241_cam). When the foldable electronic device (100) is in a folded state (or closed state), the upper cam pattern (244_cam) and the lower cam pattern (241_cam) may have a first inclination (240_sl1) and come into contact to form a third contact angle (a3). When the foldable electronic device (100) is in an unfolded state (or open state), the upper cam pattern (244_cam) and the lower cam pattern (241_cam) may have a second inclination (240_sl2) different from the first inclination (240_sl1) and come into contact to form a fourth contact angle (a4). According to one embodiment, the angle of the first inclination (240_sl1) (e.g., the third contact angle (a3)) may be greater than the angle of the second inclination (240_sl2) (e.g., the first contact angle (a2)). Alternatively, the second inclination (240_sl2) may be formed more gently than the first inclination (240_sl1). In this regard, during a certain angle at which the foldable electronic device (100) is unfolded from a folded state, a ridge on one side of the upper cam pattern (244_cam) forming the first inclination (240_sl1) and a ridge on one side of the lower cam pattern (241_cam) corresponding thereto have the same inclination and rotate while in contact with each other, and at this time, a first force (or a force of the first magnitude) may be required for rotation at the first inclination (240_sl1).When the foldable electronic device (100) is in a folded state, the upper cam pattern (244_cam) and the lower cam pattern (241_cam) come into contact with each other at a first inclination (240_sl1) to form a third contact angle (a3), and as the upper cam pattern (244_cam) and the lower cam pattern (241_cam) are pressed to rotate in different directions by an elastic force applied from the outside (e.g., the upper cam pattern (244_cam) is pressed to rotate from right to left or counterclockwise, and the lower cam pattern (241_cam) is pressed to rotate from left to right or clockwise), at least a portion of the repulsive force of the flexible display (the flexible display 160 of FIG. 2) included in the foldable electronic device (100) to unfold can be offset. According to one embodiment, while the foldable electronic device (100) is folded at a certain angle from an unfolded state, one side of the upper cam pattern (244_cam) forming the second inclination (240_sl2) and one side of the lower cam pattern (241_cam) corresponding thereto have the same inclination and rotate while in contact with each other, and at this time, a second force (or a force of a second magnitude) smaller than the first force may be required for rotation at the second inclination (240_sl2). When the foldable electronic device (100) is in an unfolded state, the upper cam pattern (244_cam) and the lower cam pattern (241_cam) come into contact with each other at a second inclination (240_sl2) to form a fourth contact angle (a4), and as the upper cam pattern (244_cam) and the lower cam pattern (241_cam) are pressed to rotate in different directions by an elastic force applied from the outside (e.g., the upper cam pattern (244_cam) is pressed to rotate from left to right or clockwise, and the lower cam pattern (241_cam) is pressed to rotate from right to left or counterclockwise), at least a part of the folding repulsive force (when the flexible display (the flexible display 160 of FIG. 2) is in a folded state for a certain period of time, a property occurs in which the flexible display tends to fold at a certain angle in the unfolded state) of the flexible display (the flexible display 160 of FIG. 2) included in the foldable electronic device (100) is folded) Can be offset. The shapes of the upper cam pattern (244_cam) and the lower cam pattern (241_cam) described above can be applied to at least some of the fixed cam parts and cams (or modified cams) described above. As an example, a structure in which two slopes forming a mountain form slopes of different angles is applied to the third cam (244c, 244g) (or the third modified cam (221_cam2)) and the fourth cam (244d, 244h) (or the fourth modified cam (222_cam2)) described above and the third fixed cam portion (241c, 236_cam1, 241_33) and the fourth fixed cam portion (241d, 236_cam2, 241_34), and the first cam (244a) (or the first modified cam (244e, 222_cam)) and the second cam (244b) (or the second modified cam (244f, 221_cam)) and the first fixed cam portion (241a, 241_31) and the second fixed cam portion (241b, 241_32) may not apply. Meanwhile, in the description of the embodiments described above, a structure in which both sides (e.g., in the x-axis direction and in the -x-axis direction) are symmetrical with respect to the horizontal center line of the fixed bracket (213) is exemplified, but the embodiments of the present disclosure are not limited thereto. For example, different types of elastic members may be arranged alternately (e.g., referring to FIG. 9, in the x-axis to -x-axis direction, the first cam elastic member (242a), the third cam elastic member (242c), the second cam elastic member (242b), and the fourth cam elastic member (242d) may be arranged in that order). Alternatively, the first cam and the second cam may be arranged adjacently, and the third cam and the fourth cam may be arranged adjacently (e.g., referring to FIG. 9, in the x-axis to -x-axis direction, the first cam elastic member (242a), the second cam elastic member (242b), the third cam elastic member (242c), and the fourth cam elastic member (242d) may be arranged in that order). In addition, elastic members capable of providing relatively high torque (e.g., the first cam elastic member (242a) and the second cam elastic member (242b) of FIG. 9) may be arranged on the inside with respect to the horizontal center line of the fixed bracket (213), and elastic members capable of providing relatively low torque (e.g., the third cam elastic member (242c) and the fourth cam elastic member (242d) of FIG. 9) may be arranged on the outside (e.g., the first cam elastic member (242a) and the second cam elastic member (242b) may be arranged between the third cam elastic member (242c) and the fourth cam elastic member (242d) with respect to FIG. 9). In the various embodiments described above, a foldable electronic device (or portable electronic device) according to one embodiment may include a first housing (110) and a second housing (120), a hinge structure (201) connecting the first housing and the second housing, and a flexible display. The hinge structure comprises: a first rotation member (211) connected to the first housing and a second rotation member (212) connected to the second housing; a first arm member (221) that rotates in response to the rotation of the first rotation member and a second arm member (222) that rotates in response to the rotation of the second rotation member; a first shaft (231) having a first main gear (221_2) disposed thereon and connected to the first arm member; a second shaft (232) having a second main gear (222_2) disposed thereon and connected to the second arm member; a third shaft (238) that is disposed between the first main gear and the second main gear and has a first gear (238a) disposed thereon; a fourth shaft (239) that is disposed between the third shaft and the second main gear and has a second gear (239a) disposed thereon; first to fourth cams (244a, 244b, 244c) that are coupled to each of the first to fourth shafts. 244c, 244d), a cam member (241) coupled to each of the first to fourth shafts and including first to fourth fixed cam portions facing the first to fourth cams, a first elastic member (242a) coupled to the first shaft and providing a first elastic force to the first cam, a second elastic member (242b) coupled to the second shaft and providing the first elastic force to the second cam, a third elastic member (242c) coupled to the third shaft and providing a second magnitude of elastic force to the third cam, and a fourth elastic member (242d) coupled to the fourth shaft and providing the second elastic force to the fourth cam. The inclination of the first cam may be different from the inclination of the third cam, and the type of the first elastic member may be formed differently from the type of the third elastic member. According to one embodiment, the first cam and the first fixed cam portion form a first contact angle by an elastic force applied by the first elastic member (or a press or pressure due to the elastic force of the first elastic member), the third cam and the third fixed cam portion form a second contact angle by an elastic force applied by the third elastic member, and when the foldable electronic device is in an unfolded state, the size of the first contact angle is smaller than the size of the second contact angle. In one embodiment, the foldable electronic device is characterized in that the amount contributed by the second contact angle (or the size of the contribution ratio) to maintain the unfolded state is greater than the amount contributed by the first contact angle. According to one embodiment, the first cam and the first fixed cam portion form a first contact angle by an elastic force applied by the first elastic member, the third cam and the third fixed cam portion form a second contact angle by an elastic force applied by the third elastic member, and while an angle between the first housing and the second housing is maintained within an angular range (or a specific angular range) defined corresponding to a partially folded state, the size of the first contact angle is formed to be the same as the size of the second contact angle. According to one embodiment, while the angle between the first housing and the second housing is maintained within an angular range defined to correspond to a partially folded state, an amount of the elastic force applied by the first elastic member contributing to maintaining the angular range is greater than an amount of the elastic force applied by the second elastic member contributing to maintaining the angular range. According to one embodiment, while the foldable electronic device provides additional rotational resistance (e.g., rotation that occurs while an elastic force is applied in a situation where the upper portions of the cams (fixed cam portion and the cams) of the hinge structure are designed to be non-flat and have a certain incline) due to rotation between the first housing and the second housing in an angular range corresponding to a partially folded state, an amount of the elastic force applied by the first elastic member contributing to maintaining the angular range is greater than an amount of the elastic force applied by the second elastic member contributing to maintaining the angular range. According to one embodiment, the first cam and the first fixed cam portion form a first cam stroke by an elastic force applied by the first elastic member, the third cam and the third fixed cam portion form a second cam stroke by an elastic force applied by the third elastic member, and when the foldable electronic device is in an unfolded state or a folded state, the movement amount of the first cam stroke is smaller than the movement amount of the second cam stroke. According to one embodiment, the first contact angle is formed to be greater than 0 degrees and less than 20 degrees, and the second contact angle is formed to be 35 degrees or more. According to one embodiment, while the angle between the first housing and the second housing maintains an angular range defined corresponding to a partially folded state, the elastic force applied by the first elastic member is set to be greater than the elastic force applied by the third elastic member and provided to the third cam. According to one embodiment, the compression amount of the third elastic member is set to be greater than the compression amount of the first elastic member while the angle between the first housing and the second housing is maintained within an angular range defined to correspond to a partially folded state. According to one embodiment, the first elastic member is characterized in that it includes a laminated structure of a plurality of disc springs, and the third elastic member includes a coil spring. According to one embodiment, the invention is characterized by further including friction members (249a1, 249a2, 249b1, 249b2) respectively arranged on the first shaft and the second shaft, and support members (248a, 248b) arranged to be in contact with the friction members. According to one embodiment, the friction members and the support members are characterized in that they are arranged between the cam member and the first arm member or between the cam member and the second arm member. According to one embodiment, the friction members and the support members are alternately arranged in multiple numbers, and the same number is arranged on the first shaft and the second shaft. According to one embodiment, the cam member is characterized in that it further includes a connecting structure connecting the first fixed cam portion, the second fixed cam portion, the third fixed cam portion, and the fourth fixed cam portion. According to one embodiment, the cam member includes a first cam member and a second cam member separated from the first cam member, the first cam member includes the first fixed cam portion, the second fixed cam portion, and a first connecting structure connecting the first fixed cam portion and the second fixed cam portion, and the second cam member includes the third fixed cam portion, the fourth fixed cam portion, and a second connecting structure connecting the third fixed cam portion and the fourth fixed cam portion. According to one embodiment, the first cam is formed integrally with one side of the first arm member, and the second cam is formed integrally with one side of the second arm member. According to one embodiment, the first cam is formed integrally with one side of the first main gear, and the second cam is formed integrally with one side of the second main gear. According to one embodiment, the third cam is formed integrally with one side of the first gear, and the fourth cam is formed integrally with one side of the second gear. According to the above-described embodiment, the hinge structure according to the embodiment comprises a first rotation member (211) that rotates around a first axis (axis_A1) and a second rotation member (212) that rotates around a second axis (axis_A2), a first arm member (221) that rotates around a third axis (axis_B3) while rotating in response to the rotation of the first rotation member, and a second arm member (222) that rotates around a fourth axis (axis_B4) while rotating in response to the rotation of the second rotation member, a first shaft (231) on which a first main gear is arranged and connected to the first arm member, a second shaft (232) on which a second main gear is arranged and connected to the second arm member, a third shaft (238) that is arranged between the first main gear and the second main gear and has a first gear (238a) arranged, a fourth shaft (239a) that is arranged between the third shaft and the second main gear and has a second gear A cam member (241) including a shaft (239), first to fourth cams (244a, 244b, 244c, 244d) coupled to each of the first to fourth shafts, first to fourth fixed cam parts (241a, 241b, 241c, 241d) coupled to each of the first to fourth shafts and facing the first to fourth cams, a first elastic member (242a) coupled to the first shaft and providing a first elastic force to the first cam, a second elastic member (242b) coupled to the second shaft and providing the first elastic force to the second cam, a third elastic member (242c) coupled to the third shaft and providing a second elastic force to the third cam, and a fourth elastic member (242d) coupled to the fourth shaft and providing the second elastic force to the fourth cam, wherein the inclination of the first cam is different from the inclination of the third cam, and the The type of the first elastic member may be formed differently from the type of the third elastic member. According to one embodiment, the size of the first contact angle at which the first cam and the first fixed cam portion of the cam member come into contact may be set smaller than the size of the second contact angle at which the third cam and the third fixed cam portion of the cam member come into contact. Meanwhile, in the description related to torque provision of the above-described hinge structure (at least one of 201, 202, 203, 204), the cams and fixed cam parts arranged on both sides with respect to the folding axis (e.g., an imaginary axis crossing the centers of the first axis (axis_A1) and the second axis (axis_A2)) are defined as the first cam structure and the second cam structure, and an example is given of a form in which different types of elastic members pressurize the first cam structure and the second cam structure, but the present disclosure is not limited thereto. For example, in the hinge structure (at least one of 201, 202, 203, 204) of the present disclosure, the first cam structure described above may be defined to include only the first cam (244a) and the first fixed cam portion (241a) in the hinge structure (at least one of 201, 202, 203, 204), and correspondingly, the elastic member that presses the first cam structure may include only the first cam elastic member (242a). Similarly, the second cam structure may include only the third cam (244c) and the third fixed cam portion (241c) in the hinge structure (at least one of 201, 202, 203, 204), and the elastic member that presses the second cam structure may include only the third cam elastic member (242c) that is different in type from the first cam elastic member (242a). Additionally, the hinge structure (at least one of 201, 202, 203, 204) may further include a third cam structure including a third cam (244c) and a third fixed cam portion (241c), a third cam elastic member (242c) that presses the third cam structure, a fourth cam structure including a fourth cam (244d) and a fourth fixed cam portion (241d), and a fourth cam elastic member (242d) that presses the fourth cam structure. According to one embodiment, the first cam elastic member (242a) may include the first type elastic member (e.g., a disk spring) exemplified above, and the third cam elastic member (242c) may include a second type elastic member (e.g., a coil spring). The third cam structure may be configured differently from the first cam structure (e.g., at least one of the contact angle between the cam and the fixed cam portion and the cam stroke is different), and the fourth cam structure may be configured differently from the second cam structure (e.g., at least one of the contact angle between the cam and the fixed cam portion and the cam stroke is different). As one embodiment, the second cam elastic member (242b) may be configured differently from the first cam elastic member (242a) (e.g., at least one of the type of the elastic member and the magnitude of the elastic force is different), and the fourth cam elastic member (242d) may be configured differently from the third cam elastic member (242c) (e.g., at least one of the type of the elastic member and the magnitude of the elastic force is different). Alternatively, the first to fourth cam elastic members (242a, 242b, 242c, 242d) may each be configured to include a plurality of types (e.g., a disk spring and a coil spring), and the application ratios of the respective types of the first to fourth cam elastic members (242a, 242b, 242c, 242d) may be configured differently. In response to this, in the embodiment of the present disclosure, when defining the characteristics of the configurations providing high torque, as an example, a hinge structure (at least one of 201, 202, 203, and 204) including a first group including a first cam (244a) and a first fixed cam portion (241a) that form a first contact angle by pressing a first cam elastic member (242a) as a first type elastic member, and a second group including a third cam (244c) and a third fixed cam portion (241c) that form a second contact angle (a contact angle different from the first contact angle) by pressing a third cam elastic member (242c) as a second type elastic member (an elastic member of a different type from the first type) can be presented. Alternatively, in an embodiment of the present disclosure, the hinge structure (at least one of 201, 202, 203, 204) includes, as an example, a third group including a second cam (244b) and a second fixed cam portion (241b) that form a third contact angle (e.g., a contact angle identical to the first contact angle or different from the first and second contact angles) by pressing of a second cam elastic member (242b) as a third type elastic member (e.g., an elastic member identical to the first type or different from the first and second types), and a fourth cam (244d) and a fourth fixed cam portion (241d) that form a fourth contact angle (e.g., a contact angle identical to the second contact angle or different from the first to third types) by pressing of a fourth cam elastic member (242d). A fourth group can be presented. According to one embodiment, in the hinge structure (at least one of 201, 202, 203, 204), the first cam (244a) and the first fixed cam portion (241a) form a first contact angle by the pressing of the first cam elastic member (242a), the third cam (244c) and the third fixed cam portion (241c) form a second contact angle by the pressing of the third cam elastic member (242c), and when the foldable electronic device (100) is in an unfolded state or a folded state, the size of the first contact angle can be formed smaller than the size of the second contact angle. According to one embodiment, the size (or contribution) of the ratio contributed by the second contact angle to maintain the unfolded state or the folded state of the foldable electronic device (100) may be greater than the size (or contribution) of the ratio contributed by the first contact angle. In one embodiment, while the foldable electronic device (100) maintains a specified angular range, additional rotational resistance (e.g., when the tops of the cam portions are not formed flat but have a constant inclination greater than 0) may be provided between the first housing and the second housing, thereby providing elasticity. According to one embodiment, the first cam (244a) and the first fixed cam portion (241a) form a first contact angle by the pressing of the first cam elastic member (242a), the third cam (244c) and the third fixed cam portion (241c) form a second contact angle by the pressing of the third cam elastic member (242c), and while the angle between the first housing (110) and the second housing (120) maintains a specific angle, the size of the first contact angle can be formed to be the same as the size of the second contact angle. According to one embodiment, while the angle between the first housing (110) and the second housing (120) is maintained at a specific angle, the size of the ratio at which the pressure generated by the first elastic force provided by the first cam elastic member (242a) contributes to maintaining the specific angle may be formed to be larger than the size of the ratio at which the pressure generated by the second elastic force provided by the third cam elastic member (242c) contributes to maintaining the specific angle. According to one embodiment, the first cam (244a) and the first fixed cam portion (241a) form a first cam stroke by the pressing of the first cam elastic member (242a), the third cam (244c) and the third fixed cam portion (241c) form a second cam stroke by the pressing of the third cam elastic member (242c), and when the foldable electronic device (100) is in an unfolded state or a folded state, the size of the first cam stroke can be formed smaller than the size of the second cam stroke. The above-described features can be applied identically or similarly to the third group and the fourth group. For example, the second cam elastic member (242b) of the third group can provide a third elastic force, and the size of the pressure generated by providing the third elastic force (or the size of the ratio that the hinge structures (201, 202, 203, 204) contribute to maintaining a specific angle) and the size of the subscription generated by providing the fourth elastic force provided by the fourth cam elastic member (242d) of the fourth group (or the size of the ratio that the hinge structures (201, 202, 203, 204) contribute to maintaining a specific angle) can vary depending on at least one of the contact angle and the cam stroke of the cam structures belonging to the corresponding group. Accordingly, the hinge structure (at least one of 201, 202, 203, 204) of the present invention may include a plurality of cams, fixed cam parts, and elastic members, and each of the cams, fixed cam parts, and elastic members belonging to at least two groups may be configured differently from each other, so that each group may contribute differently to a specific state (e.g., folded state, unfolded state, flex mode state) of the foldable electronic device (100). According to one embodiment, a foldable electronic device (100) comprises: a first housing (110) and a second housing (120); a hinge structure (201) coupled to the first housing (110) and the second housing (120); and a flexible display (160); wherein the hinge structure comprises: (201); a first rotational member (211) coupled to the first housing (110) and a second rotational member (212) coupled to the second housing (120); a first arm member (221) that rotates in response to the rotation of the first rotational member (211) and a second arm member (222) that rotates in response to the rotation of the second rotational member (212); a first shaft (231) on which a first main gear (221_2) is arranged and coupled to the first arm member (221); A second shaft (232) having a second main gear (222_2) disposed thereon and coupled to the second arm member (222); a third shaft (238) having a first gear (238a) disposed between the first main gear (221_2) and the second main gear (222_2); a fourth shaft (239) having a second gear (239a) disposed between the third shaft (238) and the second main gear (222_2); first to fourth cams (244a, 244b, 244c, 244d) coupled to the first to fourth shafts (231, 232, 238, 239), respectively; A cam member (241) including first to fourth fixed cam portions (241a, 241b, 241c, 241d) coupled to each of the first to fourth shafts (244a, 244b, 244c, 244d) and facing the first to fourth cams (244a, 244b, 244c, 244d); a first elastic member (242a) coupled to the first shaft (231) and providing a first elastic force to the first cam (244a);A second elastic member (242b) coupled to the second shaft (232) and providing the first elastic force to the second cam (244b); a third elastic member (242c) coupled to the third shaft (238) and providing the second magnitude of elastic force to the third cam (244c); and a fourth elastic member (242d) coupled to the fourth shaft (239) and providing the second elastic force to the fourth cam (244d); wherein the inclination of the first cam (244a) is different from the inclination of the third cam (244c), and the type of the first elastic member (242a) may be different from the type of the third elastic member (242c). According to the present disclosure, when a user attempts to open or close a foldable electronic device, the device can maintain controlled movement without sudden resistance changes or dislocations, enable the user to open or close the device with minimal effort and optimized smoothness, and provide a safe stop function to ensure positional stability and prevent unintended opening or closing.; According to various embodiments, the first cam (244a) and the first fixed cam portion (241a) form a first contact angle by an elastic force applied by the first elastic member (242a). The third cam (244c) and the third fixed cam portion (241c) form a second contact angle by an elastic force applied by the third elastic member (242c). When the foldable electronic device (100) is in an unfolded state, the size of the first contact angle is smaller than the size of the second contact angle. According to various embodiments, the amount contributed by the second contact angle to maintain the unfolded state or the folded state of the foldable electronic device (100) is greater than the amount contributed by the first contact angle. According to various embodiments, the first cam (244a) and the first fixed cam portion (241a) form a first contact angle by an elastic force applied by the first elastic member (242a), the third cam (244c) and the third fixed cam portion (241c) form a second contact angle by an elastic force applied by the third elastic member (242c), and while the angle between the first housing (110) and the second housing (120) maintains an angular range defined corresponding to a partially folded state, the size of the first contact angle is formed to be the same as the size of the second contact angle. According to various embodiments, while additional rotational resistance is provided as the angle between the first housing (110) and the second housing (120) has an angular range defined corresponding to a partially folded state, an amount of the elastic force applied by the first elastic member (242a) contributing to maintaining the angular range is greater than an amount of the elastic force applied by the second elastic member (242b) contributing to maintaining the angular range. According to various embodiments, the first cam (244a) and the first fixed cam portion (241a) form a first cam stroke by an elastic force applied by the first elastic member (242a), the third cam (244c) and the third fixed cam portion (241c) form a second cam stroke by an elastic force applied by the third elastic member (242c), and when the foldable electronic device (100) is in an unfolded state or a folded state, the movement amount of the first cam stroke is smaller than the movement amount of the second cam stroke. According to various embodiments, the first contact angle is formed to be greater than 0 degrees and less than 20 degrees, and the second contact angle is formed to be greater than 35 degrees. According to various embodiments, while the angle between the first housing (110) and the second housing (120) is maintained within an angular range corresponding to a partially folded state, the elastic force applied by the first elastic member (242a) is greater than the elastic force provided to the third cam (244c) by the third elastic member (242c). According to various embodiments, while the angle between the first housing (110) and the second housing (120) is maintained within an angular range corresponding to a partially folded state, the amount of compression of the third elastic member (242c) is greater than the amount of compression of the first elastic member (242a). According to various embodiments, the first elastic member (242a) includes a laminated structure of a plurality of disc springs, and the third elastic member (242c) includes a coil spring. According to various embodiments, the invention further includes friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) respectively arranged on the first shaft (231) and the second shaft (232), and support members (218a, 218b, 218c) arranged to be in contact with the friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4). According to various embodiments, the friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) and the support members (218a, 218b, 218c) are arranged between the cam member (241) and the first arm member (221) or between the cam member (241) and the second arm member (222). According to various embodiments, the friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) and the support members (218a, 218b, 218c) are alternately arranged in multiple numbers. According to various embodiments, the same number is arranged on the first shaft (231) and the second shaft (232). According to various embodiments, the cam member (241) further includes a connecting structure connecting the first fixed cam portion (241a), the second fixed cam portion (241b), the third fixed cam portion (241c), and the fourth fixed cam portion (241d). According to various embodiments, the cam member (241) includes a first cam member and a second cam member separated from the first cam member; the first cam member includes: a first fixed cam portion (241a) facing the first cam (244a); a second fixed cam portion (241b) facing the second cam (244b); and a first connecting structure connecting the first fixed cam portion (241a) and the second fixed cam portion (241b). According to various embodiments, the second cam member includes: the third fixed cam portion (241c) facing the third cam (244c); the fourth fixed cam portion (241d) facing the fourth cam (244d); and a second connecting structure connecting the third fixed cam portion (241c) and the fourth fixed cam portion (241d). According to various embodiments, the first cam (244a) is formed integrally with one side of the first arm member (221), and the second cam (244b) is formed integrally with one side of the second arm member (222). According to various embodiments, the first cam (244a) is formed integrally with one side of the first main gear (221_2), and the second cam (244b) is formed integrally with one side of the second main gear (222_2). According to various embodiments, the third cam (244c) is formed integrally with one side of the first gear (238a), and the fourth cam (244d) is formed integrally with one side of the second gear (239a). According to an embodiment of the present disclosure, a hinge structure (201) includes: a first rotational member (211) that rotates about a first axis (axis_A1) and a second rotational member (212) that rotates about a second axis (axis_A2); a first arm member (221) that rotates about a third axis (axis_B3) while rotating in response to the rotation of the first rotational member (211) and a second arm member (222) that rotates about a fourth axis (axis_B4) while rotating in response to the rotation of the second rotational member (212); a first shaft (231) on which a first main gear (221_2) is arranged and connected to the first arm member (221); a second shaft (232) on which a second main gear (222_2) is arranged and connected to the second arm member (222); A third shaft (238) disposed between the first main gear (221_2) and the second main gear (222_2) and having a first gear (238a) disposed thereon; A fourth shaft (239) disposed between the third shaft (238) and the second main gear (222_2) and having a second gear (239a) disposed thereon; First to fourth cams (244a, 244b, 244c, 244d) coupled to each of the first to fourth shafts (231, 232, 238, 239); A cam member (241) including first to fourth fixed cam portions (241a, 241b, 241c, 241d) coupled to each of the first to fourth shafts (231, 232, 238, 239) and facing the first to fourth cams (244a, 244b, 244c, 244d); a first elastic member (242a) coupled to the first shaft (231) and providing a first elastic force to the first cam (244a); a second elastic member (242b) coupled to the second shaft (232) and providing the first elastic force to the second cam (244b); a third elastic member (242c) coupled to the third shaft (238) and providing a second elastic force to the third cam (244c);A fourth elastic member (242d) coupled to the fourth shaft (239) and providing the second elastic force to the fourth cam (244d) includes: an inclination of the first cam (244a) that is different from the inclination of the third cam (244c), and a type of the first elastic member (242a) that is different from the type of the third elastic member (242c). According to the present disclosure, the hinge structure can contribute to controlling the movement of the foldable electronic device without abrupt change in resistance or detachment, and allows the user to open and close the foldable electronic device with optimal smoothness with minimal effort, and provides a safe stop function that ensures positional stability and prevents unintended opening or closing.; According to various embodiments, the size of the first contact angle at which the first cam (244a) and the first fixed cam portion (241a) of the cam member (241) come into contact is smaller than the size of the second contact angle at which the third cam (244c) and the third fixed cam portion (241c) of the cam member (241) come into contact. FIG. 14 is a block diagram of an electronic device within a network environment according to various embodiments. Referring to FIG. 14, in a network environment (1400), an electronic device (1401) may communicate with an electronic device (1402) via a first network (1498) (e.g., a short-range wireless communication network), or may communicate with at least one of an electronic device (1404) or a server (1408) via a second network (1499) (e.g., a long-range wireless communication network). According to one embodiment, the electronic device (1401) may communicate with the electronic device (1404) via the server (1408). According to one embodiment, the electronic device (1401) may include a processor (1420), a memory (1430), an input module (1450), an audio output module (1455), a display module (1460), an audio module (1470), a sensor module (1476), an interface (1477), a connection terminal (1478), a haptic module (1479), a camera module (1480), a power management module (1488), a battery (1489), a communication module (1490), a subscriber identification module (1496), or an antenna module (1497). In some embodiments, the electronic device (1401) may omit at least one of these components (e.g., the connection terminal (1478)), or may have one or more other components added. In some embodiments, some of these components (e.g., the sensor module (1476), the camera module (1480), or the antenna module (1497)) may be integrated into a single component (e.g., the display module (1460)). The processor (1420) may control at least one other component (e.g., a hardware or software component) of the electronic device (1401) connected to the processor (1420) by executing, for example, software (e.g., a program (1440)), and may perform various data processing or calculations. According to one embodiment, as at least a part of the data processing or calculations, the processor (1420) may store a command or data received from another component (e.g., a sensor module (1476) or a communication module (1490)) in a volatile memory (1432), process the command or data stored in the volatile memory (1432), and store result data in a nonvolatile memory (1434). According to one embodiment, the processor (1420) may include a main processor (1421) (e.g., a central processing unit or an application processor) or an auxiliary processor (1423) (e.g., a graphics processing unit, a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor) that can operate independently or together with the main processor (1421). For example, when the electronic device (1401) includes the main processor (1421) and the auxiliary processor (1423), the auxiliary processor (1423) may be configured to use less power than the main processor (1421) or to be specialized for a given function. The auxiliary processor (1423) may be implemented separately from the main processor (1421) or as a part thereof. The auxiliary processor (1423) may control at least a portion of functions or states associated with at least one of the components of the electronic device (1401) (e.g., the display module (1460), the sensor module (1476), or the communication module (1490)), for example, on behalf of the main processor (1421) while the main processor (1421) is in an inactive (e.g., sleep) state, or together with the main processor (1421) while the main processor (1421) is in an active (e.g., application execution) state. In one embodiment, the auxiliary processor (1423) (e.g., an image signal processor or a communication processor) may be implemented as a part of another functionally related component (e.g., a camera module (1480) or a communication module (1490)). In one embodiment, the auxiliary processor (1423) (e.g., a neural network processing unit) may include a hardware structure specialized for processing artificial intelligence models. The artificial intelligence models may be generated through machine learning. Such learning may be performed, for example, in the electronic device (1401) itself on which the artificial intelligence model is executed, or may be performed through a separate server (e.g., server (1408)). The learning algorithm may include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but is not limited to the examples described above. The artificial intelligence model may include a plurality of artificial neural network layers.The artificial neural network may be one of a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more of the above, but is not limited to the examples described above. In addition to or as an alternative to a hardware structure, the artificial intelligence model may include a software structure. The memory (1430) can store various data used by at least one component (e.g., the processor (1420) or the sensor module (1476)) of the electronic device (1401). The data can include, for example, software (e.g., the program (1440)) and input data or output data for commands related thereto. The memory (1430) can include a volatile memory (1432) or a nonvolatile memory (1434). The program (1440) may be stored as software in memory (1430) and may include, for example, an operating system (1442), middleware (1444), or an application (1446). The input module (1450) can receive commands or data to be used in a component of the electronic device (1401) (e.g., a processor (1420)) from an external source (e.g., a user) of the electronic device (1401). The input module (1450) can include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen). The audio output module (1455) can output an audio signal to the outside of the electronic device (1401). The audio output module (1455) can include, for example, a speaker or a receiver. The speaker can be used for general purposes such as multimedia playback or recording playback. The receiver can be used to receive an incoming call. According to one embodiment, the receiver can be implemented separately from the speaker or as a part thereof. The display module (1460) can visually provide information to an external party (e.g., a user) of the electronic device (1401). The display module (1460) can include, for example, a display, a holographic device, or a projector and a control circuit for controlling the device. According to one embodiment, the display module (1460) can include a touch sensor configured to detect a touch, or a pressure sensor configured to measure a strength of a force generated by the touch. The audio module (1470) can convert sound into an electrical signal, or vice versa, convert an electrical signal into sound. According to one embodiment, the audio module (1470) can obtain sound through the input module (1450), or output sound through an audio output module (1455), or an external electronic device (e.g., an electronic device (1402)) (e.g., a speaker or a headphone) directly or wirelessly connected to the electronic device (1401). The sensor module (1476) can detect an operating state (e.g., power or temperature) of the electronic device (1401) or an external environmental state (e.g., user state) and generate an electrical signal or data value corresponding to the detected state. According to one embodiment, the sensor module (1476) can include, for example, a gesture sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an IR (infrared) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. The interface (1477) may support one or more designated protocols that may be used to directly or wirelessly connect the electronic device (1401) with an external electronic device (e.g., the electronic device (1402)). In one embodiment, the interface (1477) may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface. The connection terminal (1478) may include a connector through which the electronic device (1401) may be physically connected to an external electronic device (e.g., the electronic device (1402)). According to one embodiment, the connection terminal (1478) may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector). The haptic module (1479) can convert an electrical signal into a mechanical stimulus (e.g., vibration or movement) or an electrical stimulus that a user can perceive through a tactile or kinesthetic sense. According to one embodiment, the haptic module (1479) can include, for example, a motor, a piezoelectric element, or an electrical stimulation device. The camera module (1480) can capture still images and moving images. According to one embodiment, the camera module (1480) can include one or more lenses, image sensors, image signal processors, or flashes. The power management module (1488) can manage power supplied to the electronic device (1401). According to one embodiment, the power management module (1488) can be implemented as, for example, at least a part of a power management integrated circuit (PMIC). The battery (1489) can power at least one component of the electronic device (1401). In one embodiment, the battery (1489) can include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell. The communication module (1490) may support establishment of a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device (1401) and an external electronic device (e.g., the electronic device (1402), the electronic device (1404), or the server (1408)), and performance of communication through the established communication channel. The communication module (1490) may operate independently from the processor (1420) (e.g., the application processor) and may include one or more communication processors that support direct (e.g., wired) communication or wireless communication. According to one embodiment, the communication module (1490) may include a wireless communication module (1492) (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (1494) (e.g., a local area network (LAN) communication module or a power line communication module). A corresponding communication module among these communication modules can communicate with an external electronic device (1404) via a first network (1498) (e.g., a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network (1499) (e.g., a long-range communication network such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules can be integrated into a single component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips). The wireless communication module (1492) can identify or authenticate the electronic device (1401) within a communication network such as the first network (1498) or the second network (1499) by using subscriber information (e.g., an international mobile subscriber identity (IMSI)) stored in the subscriber identification module (1496). The wireless communication module (1492) can support a 5G network after a 4G network and next-generation communication technology, for example, NR access technology (new radio access technology). The NR access technology can support high-speed transmission of high-capacity data (eMBB (enhanced mobile broadband)), terminal power minimization and connection of multiple terminals (mMTC (massive machine type communications)), or high reliability and low latency (URLLC (ultra-reliable and low-latency communications)). The wireless communication module (1492) can support, for example, a high-frequency band (e.g., mmWave band) to achieve a high data transmission rate. The wireless communication module (1492) may support various technologies for securing performance in a high-frequency band, such as beamforming, massive multiple-input and multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, or large scale antenna. The wireless communication module (1492) may support various requirements specified in the electronic device (1401), an external electronic device (e.g., the electronic device (1404)), or a network system (e.g., the second network (1499)). According to one embodiment, the wireless communication module (1492) can support a peak data rate (e.g., 20 Gbps or more) for eMBB realization, a loss coverage (e.g., 164 dB or less) for mMTC realization, or a U-plane latency (e.g., 0.5 ms or less for downlink (DL) and uplink (UL) each, or 1 ms or less for round trip) for URLLC realization. The antenna module (1497) can transmit or receive signals or power to or from the outside (e.g., an external electronic device). According to one embodiment, the antenna module (1497) can include an antenna including a radiator formed of a conductor or a conductive pattern formed on a substrate (e.g., a PCB). According to one embodiment, the antenna module (1497) can include a plurality of antennas (e.g., an array antenna). In this case, at least one antenna suitable for a communication method used in a communication network, such as the first network (1498) or the second network (1499), can be selected from the plurality of antennas by, for example, the communication module (1490). A signal or power can be transmitted or received between the communication module (1490) and the external electronic device through the selected at least one antenna. According to some embodiments, in addition to the radiator, another component (e.g., a radio frequency integrated circuit (RFIC)) can be additionally formed as a part of the antenna module (1497). According to various embodiments, the antenna module (1497) can form a mmWave antenna module. According to one embodiment, the mmWave antenna module can include a printed circuit board, an RFIC positioned on or adjacent a first side (e.g., a bottom side) of the printed circuit board and capable of supporting a designated high frequency band (e.g., a mmWave band), and a plurality of antennas (e.g., an array antenna) positioned on or adjacent a second side (e.g., a top side or a side) of the printed circuit board and capable of transmitting or receiving signals in the designated high frequency band. At least some of the above components may be interconnected and exchange signals (e.g., commands or data) with each other via a communication method between peripheral devices (e.g., a bus, a general purpose input and output (GPIO), a serial peripheral interface (SPI), or a mobile industry processor interface (MIPI)). In one embodiment, commands or data may be transmitted or received between the electronic device (1401) and an external electronic device (1404) via a server (1408) connected to a second network (1499). Each of the external electronic devices (1402 or 1404) may be the same or a different type of device as the electronic device (1401). In one embodiment, all or part of the operations executed in the electronic device (1401) may be executed in one or more of the external electronic devices (1402, 1404, or 1408). For example, when the electronic device (1401) is to perform a certain function or service automatically or in response to a request from a user or another device, the electronic device (1401) may, instead of or in addition to executing the function or service itself, request one or more external electronic devices to perform at least a part of the function or service. One or more external electronic devices that have received the request may execute at least a part of the requested function or service, or an additional function or service related to the request, and transmit the result of the execution to the electronic device (1401). The electronic device (1401) may process the result as it is or additionally and provide it as at least a part of a response to the request. For this purpose, for example, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used. The electronic device (1401) may provide an ultra-low latency service by using, for example, distributed computing or mobile edge computing. In another embodiment, the external electronic device (1404) may include an IoT (Internet of Things) device. The server (1408) may be an intelligent server using machine learning and / or a neural network.According to one embodiment, an external electronic device (1404) or server (1408) may be included in the second network (1499). The electronic device (1401) may be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on 5G communication technology and IoT-related technology. The electronic devices according to various embodiments disclosed in this document may be devices of various forms. The electronic devices may include, for example, portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliance devices. The electronic devices according to embodiments of this document are not limited to the above-described devices. It should be understood that the various embodiments of this document and the terminology used herein are not intended to limit the technical features described in this document to specific embodiments, but include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly dictates otherwise. In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as "first", "second", or "first" or "second" may be used merely to distinguish one component from another, and do not limit the components in any other respect (e.g., importance or order). When a component (e.g., a first) is referred to as "coupled" or "connected" to another (e.g., a second) component, with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component. The term "module" used in various embodiments of this document may include a unit implemented in hardware, software or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit, for example. A module may be an integrally configured component or a minimum unit of the component or a part thereof that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC). Various embodiments of the present document may be implemented as software (e.g., a program (1440)) including one or more instructions stored in a storage medium (e.g., an internal memory (1436) or an external memory (1438)) readable by a machine (e.g., an electronic device (1401)). For example, a processor (e.g., a processor (1420)) of the machine (e.g., the electronic device (1401)) may call at least one instruction among the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' simply means that the storage medium is a tangible device and does not contain signals (e.g. electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently or temporarily on the storage medium. According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded between a seller and a buyer as a commodity. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disc read only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a part of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as a memory of a manufacturer's server, a server of an application store, or an intermediary server. According to various embodiments, each component (e.g., a module or a program) of the above-described components may include a single or multiple entities, and some of the multiple entities may be separately arranged in other components. According to various embodiments, one or more components or operations of the above-described components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, the multiple components (e.g., a module or a program) may be integrated into one component. In such a case, the integrated component may perform one or more functions of each of the multiple components identically or similarly to those performed by the corresponding component of the multiple components before the integration. According to various embodiments, the operations performed by the module, program, or other component may be executed sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

Claims

1. In a foldable electronic device (100) First housing (110) and second housing (120); A hinge structure (201) connecting the first housing (110) and the second housing (120); including a flexible display (160); The above hinge structure (201) A first rotating member (211) connected to the first housing (110) and a second rotating member (212) connected to the second housing (120); A first arm member (221) that rotates in response to the rotation of the first rotation member (211) and a second arm member (222) that rotates in response to the rotation of the second rotation member (212); A first shaft (231) on which a first main gear (221_2) is arranged and connected to the first arm member (221); A second shaft (232) on which a second main gear (222_2) is arranged and connected to the second arm member (222); A third shaft (238) arranged between the first main gear (221_2) and the second main gear (222_2) and having a first gear (238a) arranged thereon; A fourth shaft (239) disposed between the third shaft (238) and the second main gear (222_2) and on which the second gear (239a) is disposed; First to fourth cams (244a, 244b, 244c, 244d) coupled to each of the first to fourth shafts (231, 232, 238, 239); A cam member (241) including first to fourth fixed cam parts (241a, 241b, 241c, 241d) coupled to each of the first to fourth shafts (244a, 244b, 244c, 244d) and facing the first to fourth cams (244a, 244b, 244c, 244d); A first elastic member (242a) coupled to the first shaft (231) and providing a first elastic force to the first cam (244a); A second elastic member (242b) coupled to the second shaft (232) and providing the first elastic force to the second cam (244b); A third elastic member (242c) coupled to the third shaft (238) and providing a second size of elastic force to the third cam (244c); It includes a fourth elastic member (242d) coupled to the fourth shaft (239) and providing the second elastic force to the fourth cam (244d); The inclination of the first cam (244a) is different from the inclination of the third cam (244c). A foldable electronic device including an elastic member, characterized in that the type of the first elastic member (242a) is formed differently from the type of the third elastic member (242c).

2. In paragraph 1, The first cam (244a) and the first fixed cam portion (241a) form a first contact angle by the elastic force applied by the first elastic member (242a), The third cam (244c) and the third fixed cam portion (241c) form a second contact angle by the elastic force applied by the third elastic member (242c). A foldable electronic device including an elastic member, characterized in that when the foldable electronic device (100) is in an unfolded state, the size of the first contact angle is smaller than the size of the second contact angle.

3. In paragraph 2, A foldable electronic device (100) including an elastic member, characterized in that the amount contributed by the second contact angle to maintain the unfolded state or the folded state is greater than the amount contributed by the first contact angle.

4. In any one of paragraphs 1 to 3, The first cam (244a) and the first fixed cam portion (241a) form a first contact angle by the elastic force applied by the first elastic member (242a), The third cam (244c) and the third fixed cam portion (241c) form a second contact angle by the elastic force applied by the third elastic member (242c). A foldable electronic device including an elastic member, characterized in that the size of the first contact angle is formed to be the same as the size of the second contact angle while the angle between the first housing (110) and the second housing (120) maintains an angular range defined to correspond to a partially folded state.

5. In any one of paragraphs 1 to 4, A foldable electronic device including an elastic member, characterized in that while additional rotational resistance is provided by providing an angular range defined by an angle between the first housing (110) and the second housing (120) corresponding to a partially folded state, an amount of elastic force applied by the first elastic member (242a) contributing to maintaining the angular range is greater than an amount of elastic force applied by the second elastic member (242b) contributing to maintaining the angular range.

6. In any one of paragraphs 1 to 5, The first cam (244a) and the first fixed cam portion (241a) form a first cam stroke by the elastic force applied by the first elastic member (242a), The third cam (244c) and the third fixed cam portion (241c) form a second cam stroke by the elastic force applied by the third elastic member (242c). A foldable electronic device including an elastic member, characterized in that when the foldable electronic device (100) is in an unfolded or folded state, the movement amount of the first cam stroke is smaller than the movement amount of the second cam stroke.

7. In paragraph 2, The above first contact angle is formed to be greater than 0 degrees and less than 20 degrees, A foldable electronic device including an elastic member, characterized in that the second contact angle is formed at 35 degrees or more.

8. In any one of paragraphs 1 to 7, While the angle between the first housing (110) and the second housing (120) is maintained within an angular range defined to correspond to a partially folded state, the elastic force applied by the first elastic member (242a) is set to be greater than the elastic force provided to the third cam (244c) by the third elastic member (242c). A foldable electronic device including an elastic member, characterized in that while the angle between the first housing (110) and the second housing (120) is maintained within an angular range defined to correspond to a partially folded state, the amount of compression of the third elastic member (242c) is set to be greater than the amount of compression of the first elastic member (242a).

9. In any one of paragraphs 1 to 8, The above first elastic member (242a) includes a laminated structure of a plurality of disc springs, A foldable electronic device including an elastic member, characterized in that the third elastic member (242c) includes a coil spring.

10. In any one of paragraphs 1 to 9, It further includes friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) respectively arranged on the first shaft (231) and the second shaft (232) and support members (218a, 218b, 218c) arranged to be in contact with the friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4); The above friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) and the above support members (218a, 218b, 218c) It is arranged between the cam member (241) and the first arm member (221) or between the cam member (241) and the second arm member (222), The above friction members (249a1, 249a2, 249b1, 249b2, 249c1, 249c2, 249c3, 249c4) and the above support members (218a, 218b, 218c) are arranged alternately in multiple numbers, A foldable electronic device including an elastic member, characterized in that the same number of elastic members are arranged on the first shaft (231) and the second shaft (232).

11. In any one of paragraphs 1 to 10, The above cam member (241) A foldable electronic device including an elastic member, characterized in that it further includes a connecting structure connecting the first fixed cam portion (241a), the second fixed cam portion (241b), the third fixed cam portion (241c), and the fourth fixed cam portion (241d).

12. In any one of paragraphs 1 to 11, The above cam member (241) comprising a first cam member and a second cam member separated from the first cam member; The above first cam member, The first fixed cam portion (241a) facing the first cam (244a); The second fixed cam portion (241b) facing the second cam (244b); It includes a first connecting structure connecting the first fixed cam part (241a) and the second fixed cam part (241b); The above second cam member, The third fixed cam portion (241c) facing the third cam (244c); The fourth fixed cam portion (241d) facing the fourth cam (244d); A foldable electronic device including an elastic member, characterized in that it includes a second connecting structure connecting the third fixed cam portion (241c) and the fourth fixed cam portion (241d).

13. In any one of paragraphs 1 to 12, The above first cam (244a) is formed integrally on one side of the first female member (221), The second cam (244b) includes an elastic member characterized by being formed integrally with one side of the second arm member (222), The above first cam (244a) is formed integrally on one side of the first main gear (221_2), The second cam (244b) includes an elastic member characterized by being formed integrally with one side of the second main gear (222_2). The above third cam (244c) is formed integrally on one side of the above first gear (238a), A foldable electronic device including an elastic member, characterized in that the fourth cam (244d) is formed integrally with one side of the second gear (239a).

14. In the hinge structure (201), A first rotation member (211) that rotates around a first axis (axis_A1) and a second rotation member (212) that rotates around a second axis (axis_A2); A first arm member (221) that rotates about a third axis (axis_B3) while rotating in response to the rotation of the first rotation member (211) and a second arm member (222) that rotates about a fourth axis (axis_B4) while rotating in response to the rotation of the second rotation member (212); A first shaft (231) on which a first main gear (221_2) is arranged and connected to the first arm member (221); A second shaft (232) on which a second main gear (222_2) is arranged and connected to the second arm member (222); A third shaft (238) arranged between the first main gear (221_2) and the second main gear (222_2) and having a first gear (238a) arranged thereon; A fourth shaft (239) disposed between the third shaft (238) and the second main gear (222_2) and on which the second gear (239a) is disposed; First to fourth cams (244a, 244b, 244c, 244d) coupled to each of the first to fourth shafts (231, 232, 238, 239); A cam member (241) including first to fourth fixed cam parts (241a, 241b, 241c, 241d) coupled to each of the first to fourth shafts (231, 232, 238, 239) and facing the first to fourth cams (244a, 244b, 244c, 244d); A first elastic member (242a) coupled to the first shaft (231) and providing a first elastic force to the first cam (244a); A second elastic member (242b) coupled to the second shaft (232) and providing the first elastic force to the second cam (244b); A third elastic member (242c) coupled to the third shaft (238) and providing a second elastic force to the third cam (244c); It includes a fourth elastic member (242d) coupled to the fourth shaft (239) and providing the second elastic force to the fourth cam (244d); The inclination of the first cam (244a) is different from the inclination of the third cam (244c). A hinge structure including an elastic member, characterized in that the type of the first elastic member (242a) is formed differently from the type of the third elastic member (242c).

15. In paragraph 14, A hinge structure including an elastic member, characterized in that the size of the first contact angle at which the first cam (244a) and the first fixed cam portion (241a) of the cam member (241) come into contact is set smaller than the size of the second contact angle at which the third cam (244c) and the third fixed cam portion (241c) of the cam member (241) come into contact.

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