Hinge device and electronic apparatus using the hinge device

Abstract

To provide a hinge device capable of opening a second housing with respect to a first housing from a closing position by one hand.SOLUTION: A hinge device is provided with a friction torque generation mechanism that has a leaf spring 41 and a friction washer on a hinge shaft 30 fixed to a second bracket 20 on a second housing side and rotatably coupled with a first bracket 10 on a first housing, and a rotation energization mechanism 60 for rotation energizing in a closing direction from a predetermined closing angle of both housings. The mechanism 60 engages with the first bracket 10, and is provided with rotary cam washers 62 and 63 with cam projecting portions 72A and 72B which are press-contacted on both sides of a fixing cam washer 61 with cam recessed portions 64A and 64B in circumferential directions of both surfaces by the leaf spring 41, and fall in the cam recessed portions by their rotation angle. By deviating an installation position of the cam projecting portion 72B in a circumferential direction and sequentially falling each cam projecting portion in each recessed portion from a predetermined closing angle of both housings, the housings are automatically closed to keep the closing state. When opening both housings, each cam projecting portion escapes from the cam recessed portion to ease rotation torque at opening.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a hinge device for electronic devices such as notebook computers and foldable mobile terminals, which connects a device body and a cover equipped with a display in an openable and closable manner, and which has a rotational biasing mechanism that applies pressure toward the closed position when the cover is closed to retract the cover and pressurize and hold the cover in the closed position with no gaps against the device body to prevent the cover from opening, and a free stop function that holds the cover at a desired open angle with frictional force, and an electronic device that uses this hinge device. [Background technology]

[0002] In electronic devices such as notebook computers, a first housing of a cover section equipped with a display and a second housing of a device main body equipped with a keyboard, etc. are connected by a hinge device so as to be able to be opened and closed. The hinge device has a configuration including a free stop mechanism that holds the open angle at any open position by frictional force when opening the first housing from a closed position where the first housing is closed against the second housing, and a rotation biasing mechanism that applies pressure toward the closed position when closing the first housing, retracts the first housing, and pressurizes the first housing against the device main body to make pressure contact with the second housing without any gaps, preventing the opening from occurring (Patent Document 1).

[0003] In this hinge device, a hinge shaft that serves as a pivot point between a first bracket to which a first housing is attached and a second housing rotates integrally with the first bracket, and the second bracket is attached rotatably relative to the hinge shaft. Friction members that rotate integrally with the hinge shaft are disposed on both axial sides of a bearing portion of the second bracket, and a free stop mechanism is formed by the pair of friction members clamping and holding the bearing portion of the second bracket with the pressure of a spring member, and friction torque is generated around the hinge shaft when the first bracket and the second bracket rotate relatively to each other.

[0004] When the first housing, which is the cover, is closed, the cover is pushed in the closing direction by hand to a predetermined angle close to the closed position, and the cover is released from the hand and rotated to be drawn into the closed position, and a preload is applied to the second housing by the spring force to hold the cover in place, preventing the cover from appearing open relative to the device body. The rotational biasing mechanism is configured to convert the relative rotation of the cam recessed member and the cam convex member around the axis of the hinge shaft into an increase or decrease in the opposing distance between the cam recessed member and the cam convex member along the axial direction of the hinge shaft, and the cam recessed member and the cam convex member are brought into pressurized contact with each other by the spring member. The cam recessed member has a cam recess with inclined valleys formed on both sides in the circumferential direction across a flat valley bottom, and the cam convex member has a cam convex member with inclined peaks formed on both sides in the circumferential direction of a flat top. In the closed position, the cam protrusion is dropped into the cam recess, and the two crests of the cam protrusion are in pressure contact with the two valleys of the cam recess, creating a cam engagement state. When the cam protrusion is dropped into the cam recess while the protruding cam plate is rotating toward the closed position, a so-called clicking sensation is obtained.

[0005] On the other hand, when opening the first housing, which is the cover, from the closed position, it is common to perform an initial opening operation by holding the first housing, which is held in the closed position by pressure to prevent the mouth from opening, with one hand and opening it in the opening direction. In this case, when the convex cam plate rotates in the closing direction, the crest of the cam convex part climbs the valley of the cam recessed part, and the convex cam plate moves against the spring force of the spring member so as to increase the inter-face distance with the fixed cam washer. In the initial opening operation, the region until the crest of the cam convex part overcomes the sliding of the valley of the cam recessed part is called the initial opening operation region. The rotational torque required to overcome the initial opening operation region by the initial opening operation increases toward the end of the initial opening operation region, and the rotational torque immediately before the overcoming is maximum, and this rotational torque is called the escape torque. When the initial opening operation is completed, the flat top of the cam protrusion comes into pressure contact with the flat surface of the fixed cam washer, so that the torque applied to the cover portion changes from being dominated by the escape torque to being dominated by the friction torque of the free stop mechanism. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-48906 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the conventional hinge device described above, the friction torque of the free stop mechanism is determined so that an operator of the electronic device can open and close the cover with one hand, and the cover can be stopped and held in that position when the operator releases his / her hand, and the friction torque is highly dependent on the pressure applied by the spring member and the friction coefficient of the friction member. The escape torque is also highly dependent on the pressure applied by the spring member, the inclination angle of the valley of the cam recess, and the friction coefficient of the sliding surface between the valley and the peak of the cam protrusion. In order to prevent the mouth from opening, the inclination angle of the valley should be increased, but this increases the escape torque, which becomes greater than the friction rotation torque of the free stop mechanism.

[0008] However, if the escape torque is greater than the frictional rotation torque of the free stop mechanism, when an attempt is made to open the cover held in the closed position with one hand, the device body may lift up, requiring the opening operation to be performed with both hands.

[0009] An object of the present invention is to provide a hinge device that allows a cover portion to be opened from a closed position with one hand relative to a device body, and a hinge device Used To provide electronic devices. [Means for solving the problem]

[0010] A first aspect of the present invention provides a hinge device for connecting a first housing that constitutes a main body of an electronic device and a second housing that constitutes a cover of the electronic device in an openable and closable manner. , No. 1. The first bracket that can be attached to the housing , No.a second bracket attached to two housings, a hinge shaft fixed to either the first bracket or the second bracket and rotatably connecting the other, a friction torque generating mechanism having a disc spring and a friction washer attached to the hinge shaft, and a rotation biasing mechanism adjacent to the friction torque generating mechanism for biasing the first and second housings to rotate in a closing direction from a predetermined closing angle, the rotation biasing mechanism comprising: a fixed cam washer rotatably attached to the hinge shaft and having cam recesses provided in the circumferential direction on both sides thereof to engage with either the first bracket or the second bracket, and rotating cam washers having cam protrusions that are pressed against both sides of the fixed cam washer by the elasticity of the disc spring and fall into the cam recesses of the fixed cam washer depending on the rotation angle, and by shifting the installation position of the cam recesses or the cam protrusions in the circumferential direction, the cam protrusions are sequentially moved from the predetermined closing angle of the first and second housings to the respective cam recesses of the fixed cam washer. cam The cam protrusions automatically close by dropping into the recesses, maintaining the closed state, and when the first housing and the second housing are opened, the cam protrusions successively escape from the cam recesses, thereby reducing the rotational torque when opening.

[0011] A hinge device according to a second aspect of the present invention that achieves the object of the present invention is a hinge device that connects a first housing that constitutes a main body of an electronic device and a second housing that constitutes a cover of the electronic device in an openable and closable manner, the hinge device comprising: a first bracket attached to the first housing; a second bracket attached to the second housing; The abovea friction torque generating mechanism having a disc spring and a friction washer mounted on the hinge shaft, and a rotation biasing mechanism adjacent to the friction torque generating mechanism for biasing the first and second housings to rotate in a closing direction from a predetermined closing angle; the rotation biasing mechanism is provided with a fixed cam washer that is rotatably mounted on the hinge shaft and engages with either the first bracket or the second bracket and has cam protrusions provided in the circumferential direction on both sides thereof, and a rotating cam washer that is pressed against both sides of the fixed cam washer by the elasticity of the disc spring and has cam recesses into which the cam protrusions of the fixed cam washer are depressed depending on the rotation angle, and by shifting the mounting position of the cam recesses or the cam protrusions in the circumferential direction, the cam protrusions are sequentially biased to the respective positions from the predetermined closing angle of the first and second housings. cam The cam protrusions automatically close by dropping into the recesses, maintaining the closed state, and when the first housing and the second housing are opened, the cam protrusions successively escape from the cam recesses, thereby reducing the rotational torque when opening.

[0012] The hinge device of the third invention for realizing the object of the present invention is the hinge device of the first or second invention, wherein the cam recess and the cam protrusion provided on the fixed cam washer and each of the rotating cam washers are formed by forming one cam shape portion on the surface of a disk-shaped cam plate body. Characterized by .

[0013] The fourth aspect of the present invention achieves the object of the present invention. electronic equipment The present invention is characterized in that the hinge device according to any one of the first to third inventions, and the first bracket and the second bracket of the hinge device are attached to a first housing and a second housing of an electronic device. do. Effect of the Invention

[0014] According to the hinge devices of the first and second inventions, the rotational torque required when opening is reduced, so that the second housing that is in the closed position can be opened with one hand, eliminating the hassle of having to hold the first housing with the other hand while opening it.

[0015] According to the hinge device of the third invention, the fixed cam washer and the rotating cam washer can be simplified in structure.

[0016] According to the electronic device of the fourth aspect of the invention, for example, the second housing can be opened from the closed position with one hand, improving usability. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1A is a perspective view showing an embodiment of an electronic device using a hinge device according to the present invention in an open state, and FIG. 1B is an enlarged perspective view of the left hinge device shown in FIG. [Diagram 2] 1(a) is a perspective view of the electronic device shown in FIG. 1(a) in a closed state as viewed from the bottom side, and FIG. [Diagram 3] 3(a) is a perspective view of the embodiment of the hinge device according to the present invention shown in Figures 1 and 2 in an open state, (b) is a view of the hinge device in (a) from the first surface side, and (c) is a perspective view of the first bracket in (a) from the second surface side. [Figure 4] FIG. 4 is an exploded perspective view of the hinge device shown in FIG. [Diagram 5] 5A, 5B, and 5C show a fixed cam washer constituting the hinge device of FIG. 4, in which (a) is a perspective view of the first surface side, (b) is a perspective view of the second surface side, and (c) is a side view. [Figure 6] 6(a) is a front view of the first surface side of the fixed cam washer shown in FIG. 5, (b) is a front view of the second surface side of the fixed cam washer shown in FIG. 5, and (c) is a diagram showing the shape (depth) of the second cam recess of the fixed cam washer shown in FIG. 5 and the angle of the recess area around the X-axis. [Figure 7] 5A and 5B show a first rotating cam washer constituting the hinge device shown in FIG. 4, in which (a) is a perspective view of the first surface side, and (b) is a perspective view of the second surface side. [Figure 8] 8(a) is a front view showing the first surface side of the first rotating cam washer shown in FIG. 7, (b) is a front view showing the first cam convex portion formed on the second surface side of the first rotating cam washer shown in FIG. 7, and (c) is a diagram showing the shape (height) of the first rotating cam washer shown in FIG. 7 and the angle between the areas of the outer convex portion and the inner convex portion around the X-axis. [Figure 9] 5A, 5B, and 5C show a second rotating cam washer constituting the hinge device shown in FIG. 4, in which (a) is a perspective view of the first surface side, (b) is a perspective view of the second surface side, and (c) is a side view. [Figure 10] 10(a) is a front view showing the second cam convex portion formed on the first surface side of the second rotating cam washer shown in FIG. 9, (b) is a front view showing the second surface side of the second rotating cam washer shown in FIG. 9, and (c) is a diagram showing the shape (height) of the second rotating cam washer shown in FIG. 9 and the angle between the areas of the outer convex portion and the inner convex portion around the X-axis. [Figure 11] 5A and 5B are diagrams for explaining the positional relationship between a first cam concave portion and a first cam convex portion in a closed position, where (a) shows the first cam concave portion and (b) shows the first cam convex portion. [Figure 12] 5A and 5B are diagrams for explaining the positional relationship between the second cam recessed portion and the second cam protruding portion in the closed position, where (a) shows the second cam recessed portion and (b) shows the second cam protruding portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0019] 1 and 2, the hinge device according to the present invention will be described using a notebook computer 1 as an example of electronic devices. In the notebook computer 1, a second housing 3, which is a cover portion carrying a display, is attached to a first housing 2, which is a device main body carrying a keyboard etc., via left and right hinge devices 100L, 100R so as to be able to be opened and closed freely. The left hinge device 100L and the right hinge device 100R are formed symmetrically, so only the left hinge device 100L will be described below.

[0020] 3 and 4, the hinge device 100L has a first bracket 10 to which the first housing 2 is attached, a second bracket 20 to which the second housing 3 is attached, and a hinge shaft 30 that connects the first bracket 10 and the second bracket 20 so as to be capable of relative rotation. The hinge device 100L also has a disc spring portion 40 composed of a plurality of disc springs that constitute a friction torque generating mechanism, and a first friction washer 91 and a second friction washer 92 that constitute friction plates. The hinge device 100L further has a free stop portion 50 and a rotation biasing mechanism 60.

[0021] When opening the second housing 3, which is the cover, from the closed position, the operation of holding the second housing 3, which is held in the closed position by a rotational biasing force in order to prevent the mouth from opening, with one hand and opening it in the opening direction is called the initial opening operation. The free stop portion 50 allows the second housing 3 to be opened or closed with one hand within a predetermined opening / closing angle range (called the free stop operating area), and allows it to be stopped at that position by frictional force when the hand is released.

[0022] The rotation biasing mechanism 60 retracts the second housing 3 within a predetermined angle range (called the initial opening operation region) between the closed position and the operation start end of the free stop operation region, thereby preventing the mouth from opening. The disc spring portion 40 applies a pressure force to the free stop portion 50 and the rotation biasing mechanism 60.

[0023] Configuration of hinge shaft 30

[0024] As shown in Fig. 4, the hinge shaft 30 has a bracket mounting shaft portion 32 formed at one axial end thereof across the flange 31, and an angular shaft portion 33 with a square shaft portion formed at the other end thereof. The second bracket 20 is fixed to the bracket mounting shaft portion 32 with a rivet 21. A first stopper portion 34 formed in a sector shape as shown in Fig. 3(b) is formed on the outer peripheral end face of the flange 31 facing radially outward. Fig. 3(b) shows the closed position of the second housing 3, and an abutment surface 34a at the tip of the first stopper portion 34 in the opening direction is in contact with an abutment surface of a second stopper portion 17 (described later) formed on the first bracket 10. 17aand are positioned with a phase difference of 180° in the closing direction around the axis of the hinge shaft 30. Therefore, when the second housing 3 rotates 180° from the closed position relative to the first housing 2, the opening of the second housing 3 is restricted. In other words, the stopper mechanism constituted by the first stopper portion 34 and the second stopper portion 17 allows the second housing 3 to be opened and closed relative to the first housing 2 within a range from the closed position to the horizontal position.

[0025] The X-axis, Y-axis, and Z-axis are defined as three mutually orthogonal axes, with the axial direction of the hinge shaft 30 (left-right direction of the first housing 2) defined as the X-axis direction, the front-rear direction of the first housing 2 defined as the Y-axis direction, and the up-down direction of the first housing 2 defined as the Z-axis direction. In addition, in Figures 1 to 3, the left-right direction in the X-axis direction as viewed from the front side of the figures is defined as the left-right direction, the front-rear direction in the Y-axis direction is defined as the front-rear direction, and the up-down direction of the Z-axis is defined as the up-down direction. Furthermore, in a member attached to the hinge shaft 30, the right side surface is defined as the first surface, and the left side surface is defined as the second surface.

[0026] Configuration of the first bracket 10

[0027] In Fig. 4, the first bracket 10 has a support piece 11 that extends in the Y-axis direction perpendicular to the axial direction of the hinge shaft 30. The support piece 11 is formed in a rectangular flat plate shape that is longer in the Y-axis direction, and a disk portion 12 that constitutes a roughly disk-shaped bearing portion is formed at the rear end. A circular insertion hole 13 is formed in the disk portion 12. A long upper attachment piece 14 extends to the right in the X-axis direction above and below the front side of the support piece 11. Shape Further, a small-diameter anti-rotation engagement hole 16 (see FIG. 3(b)) is formed in the support piece 11, and a second stopper portion 17 is formed on the outer periphery of the insertion hole 13 toward the right in the X-axis direction. The square shaft portion 33 of the hinge shaft 30 is inserted into the insertion hole 13 of the first bracket 10 up to the flange 31. A circular frictional contact portion 18 is formed on the second surface side of the disc portion 12 (see FIG. 3(c)).

[0028] Configuration of the second bracket 20

[0029] 3 and 4, the second bracket 20 is formed by bending a long and thin housing mounting piece 24 along the X-axis direction from an end of a hinge shaft mounting piece 23 in which a rivet insertion hole 22 for a rivet 21 is formed.

[0030] The disc spring portion 40, free stop portion 50, rotation biasing mechanism 60, first friction washer 91, and second friction washer 92 are inserted into the angular shaft portion 33 of the hinge shaft 30, and a nut 93 is screwed onto a threaded portion 33a formed at the end of the angular shaft portion 33 for tightening. On the angular shaft portion 33, the free stop portion 50, rotation biasing mechanism 60, first friction washer 91, disc spring portion 40, and second friction washer 92 are arranged in this order from the disk portion 12 of the first bracket 10 abutting against the flange 31 to the left in the X-axis direction, and the nut 93 is abutted against the second friction washer 92 for tightening.

[0031] Configuration of disc spring portion 40

[0032] The disc spring portion 40 is formed by stacking a plurality of (eight in this embodiment) disc springs 41. A circular insertion hole 42 is formed in the center of the disc spring 41. A first friction washer 91 and a second friction washer 92 are abutted against both left and right ends of the disc spring portion 40.

[0033] Free stop section 50 configuration

[0034] The free stop portion 50 is composed of a friction plate 52, the first surface of which forms a friction contact portion 51 and which is disposed opposite the second surface of the disc portion 12 of the first bracket 10, and a friction contact portion 18 on the second surface of the disc portion 12, and the friction contact portion 51 of the friction plate 52 and the friction contact portion 18 of the disc portion 12 are in pressurized contact with each other by the elastic force of the disc spring portion 40. Furthermore, the free stop portion 50 has a friction contact portion 19 formed on the first surface of the disc portion 12 and a friction contact portion (not shown) formed on the second surface of the flange 31 of the hinge shaft 30 and in frictional contact with the friction contact portion 19. The friction plate 52 has an engagement hole 53 formed in the center, which has the same shape as the outer shape of the angular shaft portion 33 of the hinge shaft 30, and rotates integrally with the hinge shaft 30. The hinge shaft 30 is rotatable relative to the insertion hole 13 of the first bracket 10. Therefore, when the second bracket 20 fixed to the hinge shaft 30 rotates around the hinge shaft 30 relative to the first bracket 10, the friction plate 52 rotates relative to the disk portion 12. At that time, the friction contact portion 51 of the friction plate 52 rotates while being in frictional contact with the friction contact portion 18 of the disk portion 12, generating a friction torque. Similarly, the friction contact portion (not shown) formed on the flange 31 rotates while being in frictional contact with the friction contact portion 19 of the disk portion 12, generating a friction torque. When the rotation biasing mechanism 60 leaves the initial opening operation region in which the pressure applied by the disc spring portion 40 gradually increases as the second housing 3 moves from the closed position toward the opening direction, and the second housing 3 moves into the free stop operation region, a certain elastic force is applied to the disk portion 12 of the free stop portion 50, the friction plate 52, and the flange 31, generating a predetermined friction torque.

[0035] Configuration of the rotation biasing mechanism 60

[0036] As shown in Fig. 4, the rotation biasing mechanism 60 is disposed between the first friction washer 91 and the friction plate 52. The rotation biasing mechanism 60 is configured by a fixed cam washer 61 (see Figs. 5 and 6) having a first cam recess 64A that is a cam recess and a second cam recess 64B that is a cam recess formed on both sides, a first rotating cam washer 62 (see Figs. 7 and 8) disposed on the right side of the fixed cam washer 61 in the figure (first surface side), and a second rotating cam washer 63 (see Figs. 9 and 10) disposed on the left side of the fixed cam washer 61 in the figure (second surface side).

[0037] In the rotation biasing mechanism 60, a first rotating cam washer 62 and a second rotating cam washer 63, which rotate integrally with the hinge shaft 30, are brought into pressure contact with a first cam recess 64A and a second cam recess 64B of the fixed cam washer 61 by the elastic force of the disc spring portion 40.

[0038] When the second housing 3 is opened in the open direction from the closed position, the first rotating cam washer 62 and the second rotating cam washer 63 rotate while the crests of the cam protrusions slide on the surfaces of the valleys of the cam recesses and climb against the elastic force of the disc spring 40. At that time, the first opposing distance L1 (not shown) between the fixed cam washer 61 and the first rotating cam washer 62 is expanded along the X-axis direction, and the second opposing distance L2 (not shown) between the fixed cam washer 61 and the second rotating cam washer 63 is similarly expanded. As the crests of the cam protrusions start to climb the valleys of the cam recesses, the rotational torque applied to the second housing 3 increases, and the rotational torque applied to the second housing 3 becomes maximum when (just before) it reaches the top. The maximum rotational torque at this time is called the escape torque.

[0039] A third opposing distance L3 (not shown), which is the sum of the first opposing distance L1 and the second opposing distance L2, is a length that contracts the coned disc spring portion 40, which is composed of multiple coned disc springs (compression springs), along the X-axis direction, and increases the elastic force. The free stop portion 50 sets the elastic force generated by the multiple coned disc springs 41 being contracted by the third opposing distance L3 as an appropriate elastic force.

[0040] As described above, the initial opening operation region of the rotation biasing mechanism 60, which is a predetermined angle range between the closed position and the operation start end of the free stop operation region, is the same whether, for example, only one first rotating cam washer 62 is used or whether, as in this embodiment, the first rotating cam washer 62 and the second rotating cam washer 63 are used. Although details will be described later, the initial opening operation region is set by the angle range in the circumferential direction of the valley portion provided in each cam recess of the first cam recess 64A and the second cam recess 64B of the fixed cam washer 61, which will be described later. Therefore, for example, when only one first rotating cam washer 62 is used, in order to obtain an appropriate elastic force, the cam depth of the cam recess and the cam height of the cam protrusion of the first rotating cam washer 62 are the length of the third opposing distance L3 (not shown).

[0041] In this case, the angle of the valley portion is larger than that in the case where the cam depth is set to the length of the opposing distances L1 and L2. Conversely, when the cam depth is set to the length of the opposing distances L1 and L2, the angle of the valley portion can be made smaller. As a result, when the second housing 3 starts to open from the closed position, the rotational torque applied to the first rotating cam washer 62 and the second rotating cam washer 63 is reduced. Therefore, the hinge shaft 30 is applied with a rotational torque that is the sum of the rotational torque of the first rotating cam washer 62 and the rotational torque of the second rotating cam washer 63, and the escape torque is smaller than that in the case where only one first rotating cam washer 62 is used.

[0042] In addition, the timing at which each cam protrusion of the first rotating cam washer 62 and the second rotating cam washer 63 disengages from each cam recess of the fixed cam washer 61 is shifted to disperse the escape torque and avoid concentration of the escape torque. The first cam recess 64A and the first rotating cam washer 62 form a pair of rotationally biasing cam parts, and the second cam recess 64B and the second rotating cam washer 63 form a pair of rotationally biasing cam parts.

[0043] The structure of the fixed cam washer 61 will be described with reference to FIGS.

[0044] As shown in Fig. 5, the fixed cam washer 61 has a circular insertion hole 65 formed in the center of a disk-shaped fixed cam washer body 64, through which the angular shaft portion 33 is rotatably inserted. A short arm portion 66 extends radially outward from the outer end of the fixed cam washer body 64, and an engagement pin 66a projects from a first surface side of the arm portion 66 toward the right in the X-axis direction. The engagement pin 66a is inserted into a rotation-prevention engagement hole 16 formed in the support piece 11 of the first bracket 10, and engages the fixed cam washer 61 around the axis of the hinge shaft 30 so as not to rotate. The center of the insertion hole 65 is C.

[0045] As shown in Fig. 5(a), a first cam recess 64A is formed on the first surface side of the fixed cam washer body 64, and as shown in Fig. 5(b), a second cam recess 64B is formed on the second surface side of the fixed cam washer body 64. In Fig. 6(a), the axis in the vertical direction of the paper that passes through the engagement pin 66a and center C is the Z axis, the axis in the horizontal direction of the paper that passes through center C is the Y axis, and the front-to-back direction of the paper that passes through center C is the X axis. In Fig. 6(a), the left side of the figure is the front side and the right side is the rear side, and in Fig. 6(b), left The rear side, Right side In FIG. 6(a), the clockwise direction around the center C is the rotation direction from the closed position to the open position, Figure 6 In (b), the counterclockwise direction around center C is the rotation direction from the closed position to the open position.

[0046] The first cam recess 64A shown in FIG. 6(a) and the second cam recess 64B shown in FIG. 6(b) are formed in the same shape and are formed symmetrically on the top and bottom with respect to the Y axis. A flat first concave flat cam portion 67A and a flat second concave flat cam portion 67B are formed on the first and second surfaces of the fixed cam washer body 64. The first cam recess 64A is formed on the outer periphery of the fixed cam washer body 64 with a first outer cam recess 68A constituting a cam portion having a flat sector-shaped recessed shape as a cam-shaped portion in a part of the first concave flat cam portion 67A, and a first inner cam recess 69A is formed on the inner periphery of the insertion hole 65. The first outer cam recess 68A and the first inner cam recess 69A are formed in similar shapes with the center C in between. In terms of a clock face, the position directly above on the Z axis is 12 o'clock and the position directly below is 6 o'clock, as described below.

[0047] The first outer cam recess 68A is formed at the 12 o'clock position, and the first inner cam recess 69A is formed at the 6 o'clock position. The shapes of the first outer cam recess 68A and the first inner cam recess 69A are formed symmetrically in the front-to-back direction (left-to-right direction on the paper) about the Z axis, and the first outer cam recess 68A and the first inner cam recess 69A are formed above and below the Y axis.

[0048] The first outer cam recess 68A is formed with a radius r1 radially inward from the outer circumferential edge of the fixed cam washer body 64, and the first inner cam recess 69A is formed with a radius r2 radially outward from the inner circumferential edge of the insertion hole 65. The radius r1 is larger than the radius r2. long is doing.

[0049] As shown in Figure 6(a), a straight line L11 connecting the ends of the opening directions of the first outer cam recess 68A and the first inner cam recess 69A formed on the first surface side, and a straight line L12 connecting the ends of the closing directions of the first outer cam recess 68A and the first inner cam recess 69A intersect at a center C, and the diagonal at the intersection is the first sector angle, which is 2α.

[0050] The first outer cam recess 68A and the first inner cam recess 69A have a first bottom 68a and a second bottom 69a, which are flat bottom surfaces, formed in the circumferential center. A first valley 681a with an inclined surface is formed at one circumferential end side (opening direction) of the first bottom 68a, and a second valley 682a is formed at the other circumferential end side (closing direction). The boundary between the first bottom 68a and the first valley 681a is indicated as a first recess boundary 683a, and the boundary between the first bottom 68a and the second valley 682a is indicated as a second recess boundary 684a.

[0051] A third valley portion 691a of an inclined surface is formed at one circumferential end side (opening direction) of the second bottom portion 69a, and a fourth valley portion 692a of an inclined surface is formed at the other circumferential end side (closing direction). The boundary between the second bottom portion 69a and the third valley portion 691a is indicated as a third recessed boundary portion 693a, and the boundary between the second bottom portion 69a and the fourth valley portion 692a is indicated as a fourth recessed boundary portion 694a.

[0052] As shown in Figure 6(a), a straight line L13 connecting the first recessed boundary portion 683a and the third recessed boundary portion 693a and a straight line L14 connecting the second recessed boundary portion 684a and the fourth recessed boundary portion 694a intersect at a center C, and the diagonal at the intersection is the second sector angle, which is 2β.

[0053] Next, the configuration of the second cam recess 64B will be described.

[0054] As shown in Fig. 6(b), the second cam recess 64B on the second surface side is formed in a part of the second concave flat cam portion 67B with the second outer cam recess 68B and the second inner cam recess 69B, which are cam portions having a flat sector-shaped recessed shape, formed in similar shapes around the center C. The second outer cam recess 68B is formed at the 6 o'clock position, and the second inner cam recess 69B is formed at the 12 o'clock position, and the first outer cam recess 68A and the first inner cam recess 69A shown in Fig. 6(a) are arranged upside down about the Y axis.

[0055] A fifth valley portion 681b is formed on one circumferential end side (opening direction) of the third bottom portion 68b constituting the second outer cam recess portion 68B, Third A sixth valley portion 682b is formed on the other circumferential end side (closing direction) of the bottom portion 68b. The boundary portion between the third bottom portion 68b and the fifth valley portion 681b is indicated as a fifth recessed boundary portion 683b, and the boundary portion between the third bottom portion 68b and the sixth valley portion 682b is indicated as a sixth recessed boundary portion 684b.

[0056] A seventh valley 691b of an inclined surface is formed on one circumferential end side (opening direction) of the fourth bottom 69b constituting the second inner cam recess 69B, and an eighth valley 692b of an inclined surface is formed on the other circumferential end side (closing direction). 691b The boundary between the fourth bottom 69b and the eighth valley 692b is indicated as a seventh recessed boundary 693b, and the boundary between the fourth bottom 69b and the eighth valley 692b is indicated as an eighth recessed boundary 694b.

[0057] As shown in Figure 6(b), a straight line L15 connecting the opening directions of the second outer cam recess 68B and the second inner cam recess 69B formed on the second surface side, and a straight line L16 connecting the closing directions of the second outer cam recess 68B and the second inner cam recess 69B intersect at center C, with the diagonal at the intersection being the third sector angle, which is 2α, the same angle as the first sector angle.

[0058] As shown in Figure 6(b), a straight line L17 connecting the fifth recessed boundary portion 683b and the seventh recessed boundary portion 693b and a straight line L18 connecting the sixth recessed boundary portion 684b and the eighth recessed boundary portion 694b intersect at the center C, and the diagonal at the intersection is the fourth sector angle, which is 2β, which is equal to the second sector angle.

[0059] In FIG. 6(c), the upper surface in the thickness direction of the fixed cam washer body 64 shows the area (second and fourth sector angles 2β) and shape (depth) of the first inner cam recess 69A and the second inner cam recess 69B in the circumferential direction (range of 0° to 360°), and the lower surface shows the first outer cam recess 68A and Second The area (first and third sector angles 2α) and shape (depth) in the circumferential direction (range of 0° to 360°) of the outer cam recess 68B are shown. The thickness of the fixed cam washer body 64 is represented as t.

[0060] As shown in Figures 6(a) and 6(b), the starting point of the angle 0° is set to the 12 o'clock position on the Z axis. The first inner cam recess 69A has a second bottom 69a with a depth h1 formed within an angle 2β range, and on both circumferential sides thereof, a third valley 691a and a fourth valley 692a are formed which form inclined surfaces with a predetermined sectorial angle range (α-β). The first outer cam recess 68A has a first bottom 68a with a depth h1 formed within an angle range of ±β from an angle of 180°, and on both circumferential sides thereof, a first valley 681a and a second valley 682a The depth of the fourth bottom portion 69b of the second inner cam recess 69B on the second surface side is set to h1, and the depth of the second outer cam recess 68 The depth of the third bottom portion 68b of B is set to h1. In this embodiment, the depths of the first to fourth bottom portions 68a, 69a, 68b, and 69b are set to the same depth (h1).

[0061] Next, the configuration of the first rotating cam washer 62 will be described with reference to FIGS.

[0062] The first rotating cam washer 62 having the first cam protrusion has a first engagement hole 71A, which is a rectangular inner hole that matches the outer shape of the angular shaft portion 33 of the hinge shaft 30, formed at the axial center of the first rotating cam washer body 70A. The first rotating cam washer body 70A has the same diameter as the outer diameter of the fixed cam washer body 64 of the fixed cam washer 61. As shown in Figs. 8(a) and (b), the first engagement hole 71A has a long side 71C of the inner diameter surface formed along the Z-axis direction, and a short side 71D of the inner diameter surface formed along the Y-axis direction. The first surface side of the first rotating cam washer body 70A shown in Figs. 7(a) and 8(a) is formed as a flat surface, and the first cam protrusion 72A is formed on the second surface side shown in Figs. 7(b) and 8(b).

[0063] 7(b) and 8(b), the first cam protrusion 72A is formed by forming a first outer cam protrusion 74A and a first inner cam protrusion 75A, which are cam protrusions having a flat sector-shaped convex shape as cam-shaped portions on a part of the first convex flat cam portion 73A having a flat outer surface, protruding toward the left along the X-axis direction. The first cam protrusion 72A is in pressure contact with the first cam recess 64A by the elastic force of the disc spring portion 40.

[0064] In the Z-Y plane, the first cam protrusion 72A has a first outer cam protrusion 74A formed radially inward from the outer circumferential edge of the first rotating cam washer body 70A with a radius r3, and a first inner cam protrusion 75A formed radially outward from the inner circumferential edge of the first engagement hole 71A with a radius r4. The first outer cam protrusion 74A and the first inner cam protrusion 75A are formed in similar shapes with the center C of the first engagement hole 71A as the center. The first outer cam protrusion 74A is formed at the 12 o'clock position on the Z axis, and the first inner cam protrusion 75A is formed at the 6 o'clock position on the Z axis. The first outer cam protrusion 74A and the first inner cam protrusion 75A are formed above and below the Y axis, Each shape is They are formed symmetrically in the front-back direction (left-right direction on the paper) around the Z axis. Radius r3 is longer than radius r4.

[0065] A straight line L19 connecting the opening direction ends of the first outer cam protrusion 74A and the first inner cam protrusion 75A and a straight line L20 connecting the closing direction ends of the first outer cam protrusion 74A and the first inner cam protrusion 75A intersect at a center C, and the diagonal at the intersection is the fifth sector angle, which is 2γ. The fifth sector angle 2γ is larger than the first and third sector angles 2α.

[0066] As shown in FIG. 8(b), the first outer cam protrusion 74A and the first inner cam protrusion 75A are formed in a convex shape along the circumferential direction, and have a first apex 76a and a second apex 77a formed in a flat top surface at the circumferential center. In FIG. 8(b), the counterclockwise direction around the center C is the opening direction, and the clockwise direction is the closing direction. A first peak 781a of an inclined surface is formed on one circumferential end side (opening direction) of the first peak 76a of the first outer cam protrusion 74A, and a second peak 782a of an inclined surface is formed on the other end side (closing direction). The boundary between the first peak 76a and the first peak 781a is indicated by a first convex boundary 783a, and the boundary between the first peak 76a and the second peak 782a is indicated by a second convex boundary 784a.

[0067] The first inner cam protrusion 75A has a third peak 791a formed as an inclined surface on one circumferential end side (opening direction) of the second apex 77a, and a fourth peak 792a formed as an inclined surface on the other circumferential end side (closing direction). The boundary between the second apex 77a and the third peak 791a is indicated as a third convex boundary 793a, and the boundary between the second apex 77a and the fourth peak 792a is indicated as a fourth convex boundary 794a.

[0068] A straight line L21 connecting the first convex boundary portion 783a and the third convex boundary portion 793a and a straight line L22 connecting the second convex boundary portion 784a and the fourth convex boundary portion 794a A straight line L22 connecting these two intersects at center C, and the diagonal at the intersection is the sixth sector angle, which is 2δ. The sixth sector angle 2δ is larger than the second and fourth sector angles 2β.

[0069] In Fig. 8(c), the sector-shaped area (sector angle 2γ) and shape (height) in the circumferential direction of the first outer cam protrusion 74A and the first inner cam protrusion 75A are shown on the upper surface in the thickness direction of the first rotating cam washer body 70A. As shown in Fig. 8(b), the starting point of the angle 0° is the 12 o'clock position on the Z axis, and the angle increases in the counterclockwise direction. The first apex 76a and the second apex 77a of the first outer cam protrusion 74A and the first inner cam protrusion 75A have flat top surfaces with a height of h1, and the first peak 781a, the second peak 782a, the third peak 791a, and the fourth peak 792a are formed on both sides of the flat top surfaces within a predetermined sector angle range (γ-δ). In this embodiment, the height of the first top portion 76a and the second top portion 77a is set to h1, which is equal to the depth (h1) of the first bottom portion 68a and the second bottom portion 69a.

[0070] In the first rotating cam washer 62, in the closed position, the first outer cam protrusion 74A faces the first outer cam recess 68A of the first cam recess 64A, and the first inner cam protrusion 75A faces the first inner cam recess 69A of the first cam recess 64A. An angle range (α-δ) that is the difference between half the angle α of the first sector angle (third sector angle) 2α and half the angle δ of the sixth sector angle 2δ is a first initial opening operation range in which, in the relationship between the first rotating cam washer 62 and the first cam recess 64A, the second housing 3 is pulled toward the first housing 2, and the elastic force of the disc spring portion 40 prevents the mouth from opening.

[0071] Second cam protrusion 72B The configuration of the second rotating cam washer 63 having the above structure will be described with reference to FIGS.

[0072] The second rotating cam washer 63 has a second engagement hole 71B formed in the axial center of the second rotating cam washer body 70B, which is a rectangular inner hole that matches the outer shape of the angular shaft portion 33 of the hinge shaft 30. The second rotating cam washer body 70B has the same outer diameter as the first rotating cam washer body 70A of the first rotating cam washer 62. Figures 9(a) and 10(a) show the first surface side of the second rotating cam washer body 70B, and Figures 9(b) and 10(b) show the second surface side of the second rotating cam washer body 70B. In Figures 10(a) and 10(b), the inclined axis that passes through the center C and has an inclination angle of angle θ with respect to the Z axis is defined as Z1. The second engagement hole 71B has a long side 71C of the inner diameter surface formed parallel to the inclined axis Z1, and a short side 71D of the inner diameter surface perpendicular to the long side 71C. As shown in FIGS. 9(a), (c) and 10, a mark 71E indicating the Z-axis position is formed on the outer circumferential surface of the second rotating cam washer body 70B at the 12 o'clock position on the Z-axis.

[0073] The rotation direction of the second rotating cam washer 63 from the closed position to the open position is a clockwise direction when viewed from the first surface side shown in FIG. 10(a), and the inclined axis Z1 is inclined at an angle θ in the counterclockwise direction with respect to the Z axis.

[0074] As shown in Figures 9(a), (c) and 10(a), the second cam protrusion 72B is formed on the first surface of the second rotating cam washer body 70B, and as shown in Figures 9(b) and 10(b) and (c), the second surface of the second rotating cam washer body 70B is formed as a flat surface. The second cam protrusion 72B is formed on the ZY plane in the same manner as the first cam protrusion 72A.

[0075] The second cam protrusion 72B is formed by forming a second outer cam protrusion 74B and a second inner cam protrusion 75B, which are cam-shaped portions and have a flat sector-shaped convex shape, on a part of the second convex flat cam portion 73B, which has a flat outer surface, protruding toward the right along the X-axis direction. The second cam protrusion 72B is in pressure contact with the second cam recess 64B by the elastic force of the disc spring portion 40.

[0076] In the Z-Y plane, the second cam protrusion 72B has a second outer cam protrusion 74B formed at a radius r3 radially inward from the outer circumferential edge of the second rotating cam washer body 70B, and a second inner cam protrusion 75B formed at a radius r4 radially outward from the inner circumferential edge of the second engagement hole 71B. The second outer cam protrusion 74B is formed at the 6 o'clock position on the Z axis, and the second inner cam protrusion 75B is formed at the 12 o'clock position on the Z axis. The second inner cam protrusion 75B and the second outer cam protrusion 74B are formed above and below the Y axis, and the second outer cam protrusion 74B and the second inner cam protrusion 75B Each shape is formed symmetrically in the front-back direction (left-right direction on the paper) around the Z axis.

[0077] The second outer cam protrusion 74B has a fifth peak 781b of an inclined surface formed on one circumferential end side (opening direction) of the third apex 76b, and a sixth peak 782b of an inclined surface formed on the other circumferential end side (closing direction) of the third apex 76b. Meanwhile, the second inner cam protrusion 75B has a seventh peak 791b of an inclined surface formed on one circumferential end side (opening direction) of the fourth apex 77b, and an eighth peak 792b of an inclined surface formed on the other circumferential end side (closing direction) of the fourth apex 77b.

[0078] Here, the boundary between the third apex 76b and the fifth peak 781b is indicated as a fifth convex boundary 783b, the boundary between the third apex 76b and the sixth peak 782b is indicated as a sixth convex boundary 784b, the boundary between the fourth apex 77b and the seventh peak 791b is indicated as a seventh convex boundary 793b, and the boundary between the fourth apex 77b and the eighth peak 792b is indicated as an eighth convex boundary 794b.

[0079] A straight line L23 connecting the ends of the second outer cam convex portion 74B and the second inner cam convex portion 75B in the opening direction and a straight line L24 connecting the ends of the second outer cam convex portion 74B and the second inner cam convex portion 75B in the opening direction intersect at the center C, and the diagonal at the intersection is the seventh sector angle, which is 2γ.

[0080] A straight line L25 connecting the fifth convex boundary portion 783b and the seventh convex boundary portion 793b and a straight line L26 connecting the sixth convex boundary portion 784b and the eighth convex boundary portion 794b intersect at the center C, and the diagonal at the intersection is the eighth sector angle, which is 2δ.

[0081] In FIG. 10(c), the area (sector angle 2γ) and shape (height) in the circumferential direction of the second outer cam protrusion 74B and the second inner cam protrusion 75B are shown on the upper surface in the thickness direction of the second rotating cam washer body 70B. As shown in FIG. 10(a), the 12 o'clock position on the Z axis is the starting point of the angle 0°. The third apex 76b and the fourth apex 77b of the second outer cam protrusion 74B and the second inner cam protrusion 75B have flat top surfaces with a height of h1, and the fifth peak 781b, the sixth peak 782b, the seventh peak 791b, and the eighth peak 792b are formed on both sides of the flat top surfaces within a predetermined sector angle range (γ-δ). In this embodiment, the height of the third peak 76b and the fourth peak 77b is h1, which is equal to the depth (h1) of the third bottom 68b and the depth (h1) of the fourth bottom 69b.

[0082] In the hinge device 100L of this embodiment, the hinge shaft 30 is rotatably supported in the insertion hole 13 of the first bracket 10, and the hinge shaft 30 rotates integrally with the second bracket 20. The fixed cam washer 61 has an engagement pin 66a engaged with the anti-rotation engagement hole 16 of the first bracket 10, and the hinge shaft 30 is rotatably inserted into the insertion hole 65. The first rotating cam washer 62 has a first engagement hole 71A engaged with the square shaft portion 33 of the hinge shaft 30, and the second rotating cam washer 63 has a second engagement hole 71B engaged with the square shaft portion 33 of the hinge shaft 30, so that the first rotating cam washer 62 rotates integrally with the hinge shaft 30.

[0083] The positional relationship between the first cam recess 64A of the fixed cam washer 61 and the first cam protrusion 72A of the first rotating cam washer 62 will be described with reference to Fig. 11. For ease of explanation, Fig. 11 shows a state viewed from the first surface side, and the first cam protrusion 72A formed on the second surface side is shown in a see-through state in Fig. 11(b) and indicated by a solid line.

[0084] 11(a), the first cam recess 64A of the fixed cam washer 61 is set such that the circumferential centers of the first bottom 68a of the first outer cam recess 68A and the second bottom 69a of the first inner cam recess 69A are set at the 12 o'clock and 6 o'clock positions on the Z axis. In contrast, the first cam protrusion 72A of the first rotating cam washer 62 is set such that the circumferential centers of the first apex 76a of the first outer cam protrusion 74A and the second apex 77a of the first inner cam protrusion 75A are set at the 12 o'clock and 6 o'clock positions on the Z axis.

[0085] The first outer cam protrusion 74A of the first rotating cam washer 62 abuts so as to overlap with the first outer cam recess 68A of the first cam recess 64A, and the first inner cam protrusion 75A abuts so as to overlap with the first inner cam recess 69A. In the closed position, the overlapping state is symmetrical in the front-rear direction (left-right direction on the paper) about the Z axis. The first sector angle 2α of the first outer cam recess 68A is smaller than the fifth sector angle 2γ of the first outer cam protrusion 74A. In addition, the second sector angle 2β of the first bottom 68a of the first outer cam recess 68A is smaller than the sixth sector angle 2δ of the first top 76a of the first outer cam protrusion 74A.

[0086] Therefore, the first peak 781a abuts on the slope of the first valley 681a constituting the first outer cam recess 68A such that the first convex boundary 783a of the first outer cam projection 74A is located. Similarly, the second peak 782a abuts on the slope of the second valley 682a such that the second convex boundary 784a is located. Also, the third convex boundary 793a of the first inner cam projection 75A is located on the slope of the third valley 691a constituting the first inner cam recess 69A and the third peak 791a abuts, and the fourth convex boundary 794a is located on the slope of the fourth valley 692a and the fourth peak 792a abuts.

[0087] The depth h1 of the first bottom 68a of the first outer cam recess 68A is equal to the height h1 of the first top 76a of the first outer cam protrusion 74A, and the depth h1 of the second bottom 69a of the first inner cam recess 69A is equal to the height h1 of the second top 77a of the first inner cam protrusion 75A. However, the first convex boundary 783a, the second convex boundary 784a, the third convex boundary 793a, and the fourth convex boundary 794a abut on the slopes of the first valley 681a, the second valley 682a, the third valley 691a, and the fourth valley 692a, respectively. Therefore, in the closed position, a first initial gap D1 (not shown) is formed along the X-axis direction between the first concave flat cam portion 67A of the fixed cam washer 61 and the first convex flat cam portion 73A of the first rotating cam washer 62. Therefore, the first rotating cam washer 62 is biased toward the fixed cam washer 61 by the elastic force of the disc spring portion 40 generated by the first initial gap D1, and an elastic force (first pressure) in the closing direction is applied to the first rotating cam washer 62. That is, the first spring force is applied in the closing direction to the second housing 3 in the closed position, preventing the mouth from opening.

[0088] At the initial time of opening the second housing 3 in the opening direction from the closed position, the hinge shaft 30 rotates in the opening direction, and a rotational torque in the opening direction is applied to the first rotating cam washer 62. At that time, the first rotating cam washer 62 slides and moves so that the first peak 781a and the third peak 791a on the opening direction side climb the slopes of the first valley 681a and the third valley 691a. Note that the second peak 782a and the fourth peak 792a on the closing direction side move away from the slopes of the second valley 682a and the fourth valley 692a. Here, the first peak 781a and the third peak 791a, whose peaks and valleys slide against each other when the hinge shaft 30 rotates in the opening direction, are referred to as first click peaks, and the first valley 681a and the third valley 691a are referred to as first click valleys. The first click crest portion slides against the first click valley portion, resisting the elastic force of the disc spring portion 40, and a click action is performed in which the fixed cam washer 61 and the first rotating cam washer 62 rotate while widening the opposing distance along the X-axis direction.

[0089] Then, when the first click peak overcomes the first click valley and the sliding of the first rotating cam washer 62 ends, the first apex 76a and the second apex 77a move into a free stop region where they slide against the first concave flat surface cam portion 67A. The escape torque applied to the first rotating cam washer 62 when the first click peak overcomes the first click valley is greater than the rotation torque after the transition to the free stop region because the first click peak climbs while sliding circumferentially on the slope of the first click valley.

[0090] When the first click crest abuts against the first concave flat cam portion 67A, the inter-surface distance (gap) between the first concave flat cam portion 67A of the fixed cam washer 61 and the first convex flat cam portion 73A of the first rotating cam washer 62 is the cam height h1 of the first click crest. The frictional rotation torque required for the free stop portion 50 depends on the elastic force of the disc spring portion 40, and depends on the elastic force (hereinafter referred to as appropriate elastic force) corresponding to the spring compression amount (hereinafter referred to as appropriate spring compression amount) of twice the length (2h1) of the cam height (h1) of the first click crest. Therefore, the appropriate elastic force cannot be obtained by the first rotating cam washer 62 alone. Therefore, the appropriate spring compression amount is obtained by the first rotating cam washer 62 and the second rotating cam washer 63.

[0091] Next, the positional relationship between the second cam recess 64B of the fixed cam washer 61 and the second cam protrusion 72B of the second rotating cam washer 63 will be described with reference to Fig. 12. For ease of explanation, Fig. 12 shows a state viewed from the second surface side, and the second cam protrusion 72B formed on the first surface side is shown in a see-through state in Fig. 12(b) and indicated by a solid line.

[0092] With the second engagement hole 71B engaged with the angular shaft portion 33 of the hinge shaft 30, the Z1 axis of the second rotating cam washer 63 coincides with the Z axis of the second cam recessed portion 64B. Then, the second cam protrusion 72B of the second rotating cam washer 63 is overlapped with the second cam recessed portion 64B with a rotational shift of angle θ in the opening direction. Furthermore, the second cam protrusion 72B is positioned with a shift of angle θ in the opening direction with respect to the first cam protrusion 72A of the first rotating cam washer 62.

[0093] 12(a), the second cam recess 64B of the fixed cam washer 61 is set such that the circumferential centers of the third bottom 68b of the second outer cam recess 68B and the fourth bottom 69b of the second inner cam recess 69B are set at the 6 o'clock and 12 o'clock positions on the Z axis. In contrast, the second cam protrusion 72B of the second rotating cam washer 63 is set such that the circumferential centers of the third apex 76b of the second outer cam protrusion 74B and the fourth apex 77b of the second inner cam protrusion 75B are shifted by an angle θ in the opening direction from the 6 o'clock and 12 o'clock positions on the Z axis.

[0094] The second outer cam protrusion 74B of the second rotating cam washer 63 abuts against the second outer cam recess 68B of the second cam recess 64B so as to overlap with the second outer cam recess 68B of the second cam recess 64B with a deviation of angle θ in the opening direction, and the second inner cam protrusion 75B abuts against the second inner cam recess 69B so as to overlap with the second inner cam recess 69B with a deviation of angle θ in the opening direction. The third sector angle 2α of the second outer cam recess 68B is smaller than the seventh sector angle 2γ of the second outer cam protrusion 74B. Also, the fourth sector angle 2β of the fourth bottom 69b of the second inner cam recess 69B is smaller than the eighth sector angle 2δ of the third top 76b of the second outer cam protrusion 74B. Therefore, the second rotating cam washer 63 overlaps with the second cam recess 64B in the same manner as the first rotating cam washer 62 overlaps with the first cam recess 64A of the fixed cam washer 61.

[0095] However, the closed position is a state in which the second outer cam protrusion 74B and the second inner cam protrusion 75B of the second rotating cam washer 63 overlap with the second outer cam recess 68B and the second inner cam recess 69B of the second cam recess 64B with a rotational shift of angle θ in the opening direction. Here, the fifth peak 781b of the second outer cam protrusion 74B and the seventh peak 791b of the second inner cam protrusion 75B (hereinafter referred to as the second click peak) come into contact with the fifth valley 681b and the seventh valley 691b (hereinafter referred to as the second click valley) of the second outer cam recess 68B. In this case, the contact position where the fifth convex boundary 783b and the seventh convex boundary 793b of the second click crest contact the second click valley portion is shifted by an angle θ in the opening direction from the contact position between the first click crest portion of the first rotating cam washer 62 and the first click valley portion of the first cam recess 64A in the closed position. Since the second click crest portion climbs the second click valley portion in response to the shift of the angle θ, a second initial gap D2 (not shown) is formed along the X-axis direction between the second convex flat cam portion 73B of the second rotating cam washer 63 and the second concave flat cam portion 67B of the fixed cam washer 61. The second initial gap D2 is longer than the first initial gap D1.

[0096] Therefore, in reality, the elastic force (second spring force) of the disc spring portion 40 generated by the first initial gap D1 and the second initial gap D2 urges the first rotating cam washer 62 and the second rotating cam washer 63 toward the fixed cam washer 61, and a second spring force is applied to the first rotating cam washer 62 and the second rotating cam washer 63 in the closing direction.

[0097] In this embodiment, the first rotating cam washer 62 and the second rotating cam washer 63 are used in order to reduce the pull-out torque by lowering the cam height, and the deviation of the angle θ is provided in order to disperse the pull-out torque. In other words, this is a configuration that reduces the rotational torque when the valve is opened.

[0098] First, the reason for lowering the cam height is as follows. The difference between the angle α and the angle β (α-β) is the area on the plane of the first valley portion 681a (third valley portion 691a) as shown in FIG. 11. If the appropriate elastic force is to be secured only by the first rotating cam washer 62, the cam depth of the first cam recessed portion 64A of the fixed cam washer 61 must be doubled to 2h1, and the cam height of the first cam protruding portion 72A of the first rotating cam washer 62 must also be doubled to 2h1. Since the rotation angle of the first initial opening operation area (α-δ) does not change, the inclination angle of the first click valley portion becomes large.

[0099] When the appropriate elastic force is applied to the first rotating cam washer 62 along the X-axis direction, a comparison is made between the case where the cam depth of the first cam recess 64A is h1 and the case where it is doubled to 2h1. Since the greater the inclination angle of the first click valley, the greater the pull-out torque applied to the hinge shaft 30, the pull-out torque is smaller when the cam depth of the first cam recess 64A is h1 than when the cam depth is doubled to 2h1.

[0100] In addition, the angle range (α-δ) which is the difference between angle α, which is half the first sector angle (third sector angle) 2α, and angle δ, which is half the eighth sector angle 2δ, is further subtracted from the first initial opening operation region to obtain an angle (α-δ-θ), which is the angle in which, in relation to the second rotating cam washer 63 and the second cam recess 64B, the second housing 3 is pulled toward the first housing 2, and the elastic force of the disc spring portion 40 prevents the mouth from opening.

[0101] Therefore, when the second housing 3 starts to open in the closing direction from the closed position, the click ridge of the click protrusion of the second rotating cam washer 63 first Fixed cam washer 61 The first rotating cam washer 62 climbs up the click valley of the click recess, and then the click crest of the click protrusion Fixed cam washer 61It climbs up the click valley of the click recess and transitions to the free stop region. The timing at which the click crest of the first rotating cam washer 62 climbs up the click valley of the fixed cam washer 61 differs from the timing at which the click crest of the second rotating cam washer 63 climbs up the click valley of the fixed cam washer 61, so the generation of the break-out torque is dispersed.

[0102] Therefore, in a closed state where the second housing 3 of the notebook computer 1 is closed to the first housing 2 in the closed position, the rotational force required to open the second housing 3 in the closing direction is lighter than in the past, allowing the opening operation to be performed with one hand.

[0103] Other embodiments

[0104] Contrary to the above embodiment, a first cam convex portion and a second cam convex portion may be provided on the fixed cam washer 61, a first concave cam portion may be provided on the first rotating cam washer 62 that rotates integrally with the hinge shaft 30, and a second concave cam portion may be provided on the second rotating cam washer 63.

[0105] Furthermore, the first cam recess 64A and the second cam recess 64B of the fixed cam washer 61 each have a pair of similar outer cam recesses and inner cam recesses formed on the outer periphery and inner periphery as cam-shaped portions, and the first cam protrusion 72A of the first rotating cam washer 62 and the second cam protrusion 72B of the second rotating cam washer 63 also have a pair of similar outer cam protrusions and inner cam protrusions formed on the outer periphery and inner periphery as cam-shaped portions. Alternatively, the cam-shaped portions may be combined into one by widening the radial width of either one of the pair of outer cam recesses or inner cam recesses. [Industrial Applicability]

[0106] The hinge device of the present invention allows the second housing to be closed with one hand, and is therefore suitable for use in electronic devices such as video display devices, portable game consoles, and notebook computers. [Explanation of symbols]

[0107] 1: Laptop 2: 1st housing 3: 2nd housing 100: Hinge device 10: First bracket 20: Second bracket 30: Hinge shaft 40: Disc spring part 50: Free stop section 60: Rotational biasing mechanism 61: Fixed cam washer 62: 1st rotating cam washer 64A: First cam recess 67A: First concave flat cam part 68A: First outer cam recess 69A: First inner cam recess 64B: Second cam recess 67B: Second concave flat cam part 68B: Second outer cam recess 69B: Second inner cam recess 70A: 1st rotating cam washer body 70B: Second rotating cam washer body 72A: First cam protrusion 73A: First convex flat cam part 74A: First outer cam protrusion 75A: First inner cam protrusion 63: Second rotating cam washer 75B: Second inner cam protrusion 91: First friction washer 92: Second friction washer 93: Nut

Claims

1. A hinge device that connects a first housing that constitutes a main body of an electronic device and a second housing that constitutes a cover of the electronic device in an openable and closable manner, a first bracket attached to the first housing; a second bracket attached to the second housing; a hinge shaft fixed to one of the first bracket and the second bracket and rotatably connecting the other of the first bracket and the second bracket; a friction torque generating mechanism having a disc spring and a friction washer installed on the hinge shaft; A rotation biasing mechanism is provided adjacent to the friction torque generating mechanism and biases the first and second housings in a closing direction from a predetermined closing angle, a rotating cam washer provided on both sides of the fixed cam washer, the rotating cam washer being pressed against the fixed cam washer by the elasticity of the disc spring, the rotating cam washer having cam convexities that drop into the cam concaves of the fixed cam washer depending on the rotation angle, and by shifting the installation position of the cam concaves or the cam convexities in the circumferential direction, the first housing and the second housing are automatically closed by the cam convexities sequentially dropping into the cam concaves from a predetermined closing angle, thereby maintaining the mutual closed state, and when the first housing and the second housing are opened, the cam convexities sequentially escape from the cam concaves, thereby reducing the rotational torque during opening.

2. A hinge device that connects a first housing that constitutes a main body of an electronic device and a second housing that constitutes a cover of the electronic device in an openable and closable manner, a first bracket attached to the first housing; a second bracket attached to the second housing; a hinge shaft fixed to one of the first bracket and the second bracket and rotatably connecting the other of the first bracket and the second bracket; a friction torque generating mechanism having a disc spring and a friction washer installed on the hinge shaft; A rotation biasing mechanism is provided adjacent to the friction torque generating mechanism and biases the first and second housings in a closing direction from a predetermined closing angle, a rotating cam washer provided on both sides of the fixed cam washer, the rotating cam washer being pressed against the fixed cam washer by the elasticity of the disc spring, the rotating cam washer having cam recesses into which the cam protrusions of the fixed cam washer fall depending on the rotation angle, and by shifting the installation position of the cam recesses or the cam protrusions in the circumferential direction, the first housing and the second housing are automatically closed by the cam protrusions sequentially falling into the cam recesses from a predetermined closing angle, thereby maintaining the mutual closed state, and when the first housing and the second housing are opened, the cam protrusions sequentially escape from the cam recesses, thereby reducing the rotational torque at the time of opening.

3. The hinge device according to claim 1 or 2, a cam recess and a cam protrusion provided on the fixed cam washer and each of the rotating cam washers, each of which is formed by forming a single cam-shaped portion on a surface of a disk-shaped cam plate body.

4. 4. An electronic device comprising: the hinge device according to claim 1; and a first bracket and a second bracket of the hinge device attached to a first housing and a second housing of the electronic device.

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