Hinge device and electronic device 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 laptop 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 closing the cover to retract the cover and pressurize and hold the cover in the closed position without any gaps against the device body, preventing the cover from opening, and a free stop function that uses friction to hold the cover at a desired open angle, and to electronic devices that use this hinge device. [Background technology]

[0002] In electronic devices such as laptop computers, a first housing of a cover with a display and a second housing of the device body with a keyboard, etc. are connected by a hinge device so that they can be opened and closed. The hinge device has a configuration that includes a free stop mechanism that uses friction to maintain the open angle at any open position when the first housing is opened from a closed position where it is closed against the second housing, and a rotational biasing mechanism that applies pressure toward the closed position when the first housing is closed, pulling the first housing in and bringing the first housing into pressure contact with the second housing without any gaps against the device body, preventing the opening (Patent Document 1).

[0003] In this hinge device, a hinge shaft that forms 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 so as to be rotatable 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 relative to each other.

[0004] The rotational biasing mechanism allows the cover, which is the first housing, to be closed by manually pushing the cover in the closing direction up to a predetermined angle close to the closed position. The cover then releases from the hand and rotates toward the closed position, applying a spring force to the second housing to hold it in place, preventing the cover from appearing open relative to the device body. The rotational biasing mechanism converts the relative rotation of the cam recessed member and the cam protruding 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 protruding member along the axial direction of the hinge shaft, and the spring member brings the cam recessed member and the cam protruding member into pressurized contact. The cam recessed member has a cam recess with sloped valleys formed on both circumferential sides of a flat valley bottom, and the cam protruding member has a cam protruding member with sloped peaks formed on both circumferential sides of a flat peak. In the closed position, the cam protrusion drops into the cam recess, and the two crests of the cam protrusion press into contact with the two valleys of the cam recess, creating a cam engagement state. When the cam protrusion drops into the cam recess as the protruding cam plate rotates toward the closed position, a clicking sensation is felt.

[0005] On the other hand, when opening the first housing (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 cover 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 crests of the cam convexity climb the valleys of the cam recesses, causing the convex cam plate to move against the spring force of the spring member, increasing the interfacial distance with the fixed cam washer. During the initial opening operation, the region until the crests of the cam convexity overcome the sliding of the valleys of the cam recesses is called the initial opening operation region. The rotational torque required to overcome the initial opening operation region by the initial opening operation increases as the initial opening operation region ends, reaching a maximum just before the region is overcome; 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, and the torque applied to the cover portion shifts 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] Japanese Patent Application Laid-Open No. 2015-48906 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 or close the cover with one hand, and can stop and hold the cover in that position when the operator releases the hand, and the friction torque is highly dependent on the pressure of the spring member and the friction coefficient of the friction member. Furthermore, the breakaway torque is highly dependent on the pressure of the spring member, the inclination angle of the valleys of the cam recess, and the friction coefficient of the sliding surfaces between the valleys and the peaks of the cam protrusion. Increasing the inclination angle of the valleys would prevent the mouth from opening, but this would increase the breakaway torque, which would be 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 you try to open the cover part that is held in the closed position with one hand, the device body will lift up, and you may have to use both hands to open the cover.

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

[0010] A hinge device of a first invention that achieves the object of the present invention is a hinge device that connects a first housing that forms a main body of an electronic device and a second housing that forms a cover of the electronic device in an openable and closable manner, and includes: a first bracket attached to the first housing; a second bracket attached to the second housing; 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 rotational biasing mechanism that is adjacent to the hinge shaft and that rotates and biases the first and second housings in the closing direction from a predetermined closing angle, the rotational biasing mechanism comprising: a fixed cam washer that is rotatably provided with respect to the hinge shaft and engages with either the first bracket or the second bracket and has cam recesses that are provided in the circumferential direction on both sides thereof; and rotating cam washers that are pressed against both sides of the fixed cam washer by the elasticity of the disc springs and have cam protrusions that drop into the cam recesses of the fixed cam washer depending on the rotation angle; On the other hand Cam recess and The aforementioned On the other hand The installation position of the cam protrusion each other By shifting the cams in the circumferential direction, the first and second housings are automatically closed by the cam convex portions sequentially dropping into the cam concave portions from a predetermined closing angle, thereby maintaining the closed state between the first and second housings, and when opening the first and second housings, the cam convex portions sequentially escape from the cam concave portions, 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 forms a main body of an electronic device and a second housing that forms a cover of the electronic device in an openable and closable manner, and includes a first bracket attached to the first housing, a second bracket attached to the second housing, 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 friction torque generating mechanism. In a device having a rotational biasing mechanism that is adjacent to the first housing and that rotates and biases the second housing in the closing direction from a predetermined closing angle, the rotational biasing mechanism is provided with a fixed cam washer that is rotatably provided with respect to 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 dropped depending on the rotation angle, On the other hand Cam recess and The aforementioned On the other hand The installation position of the cam protrusion each other By shifting the cams in the circumferential direction, the first and second housings are automatically closed by the cam convex portions sequentially dropping into the cam concave portions from a predetermined closing angle, thereby maintaining the closed state between the first and second housings, and when opening the first and second housings, the cam convex portions sequentially escape from the cam concave portions, thereby reducing the rotational torque when opening.

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

[0013] The fourth invention achieves the object of the present invention. electronic equipmentThe 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. [Effects of the Invention]

[0014] According to the hinge devices of the first and second inventions, the rotational torque when opening is reduced, so that the second housing that is closed 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 made to have a simple 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 explanation of the drawings]

[0017] [Figure 1] 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. 1A. [Figure 2] 1(a) is a perspective view of the electronic device shown in FIG. 1(a) in a closed state as seen from the bottom side, and FIG. 1(b) is an enlarged perspective view of the left hinge device shown in FIG. 1(a). [Figure 3] 1 and 2, (b) is a view of the hinge device of (a) from the first surface side, and (c) is a view of the first bracket of (a) from the second surface side. [Figure 4] FIG. 4 is an exploded perspective view of the hinge device shown in FIG. 3. [Figure 5] 5A, 5B, and 5C show a fixed cam washer constituting the hinge device of FIG. 4, in which FIG. 5A is a perspective view of the first surface side, FIG. 5B is a perspective view of the second surface side, and FIG. 5C 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 FIG. 5A is a perspective view of the first surface side, and FIG. 5B 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 protrusion 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 outer protrusion and inner protrusion areas 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 FIG. 5A is a perspective view of the first surface side, FIG. 5B is a perspective view of the second surface side, and FIG. 5C is a side view. [Figure 10] 10(a) is a front view showing the second cam protrusion 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 outer protrusion and inner protrusion areas around the X-axis. [Figure 11] 10A and 10B are diagrams illustrating the positional relationship between the first cam recess and the first cam protrusion in the closed position, where FIG. 10A shows the first cam recess and FIG. [Figure 12] 10A and 10B are diagrams illustrating the positional relationship between the second cam recess and the second cam protrusion in the closed position, where FIG. 10A shows the second cam recess and FIG. DETAILED DESCRIPTION OF THE INVENTION

[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 an electronic device. In the notebook computer 1, a second housing 3, which is a cover unit mounting a display, is attached to a first housing 2, which is a device main body mounting a keyboard and the like, via left and right hinge devices 100L and 100R so that the second housing 3 can 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 that they can rotate relative to each other. The hinge device 100L also has a disc spring portion 40 made up of multiple disc springs that forms a friction torque generating mechanism, and first and second friction washers 91 and 92 that form friction plates. The hinge device 100L also has a free stop portion 50 and a rotational 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 to prevent it from opening, with one hand and opening it in the opening direction is called the initial opening operation. The free stop unit 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 range), and can be stopped at that position by frictional force when the hand is released.

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

[0023] Configuration of hinge shaft 30

[0024] As shown in Figure 4, the hinge shaft 30 has a bracket mounting shaft 32 formed at one axial end thereof across the flange 31, and a square shaft 33 formed at the other axial end thereof. The second bracket 20 is fixed to the bracket mounting shaft 32 with a rivet 21. A first stopper 34 formed in a fan shape as shown in Figure 3(b) is formed on the outer peripheral end face of the flange 31, facing outward in the radial direction. Figure 3(b) shows the closed position of the second housing 3, and the abutment surface 34a at the tip of the first stopper 34 in the opening direction is in contact with the abutment surface of a second stopper 17 (described later) formed on the first bracket 10. 17a and 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 made up of 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 axes that are perpendicular to one another, with the axial direction of the hinge shaft 30 (the 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. Also, in Figures 1 to 3, the left-right direction in the X-axis direction as viewed from the front side of the figure 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, the right-hand surface of a member attached to the hinge shaft 30 is defined as the first surface, and the left-hand surface is defined as the second surface.

[0026] Configuration of the first bracket 10

[0027] In Figure 4, the first bracket 10 has a support piece 11 that extends in the Y-axis direction, which is 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 forms a roughly disk-shaped bearing is formed at the rear end. A circular insertion hole 13 is formed in the disk portion 12. A long upper mounting piece 14 extends to the right in the X-axis direction above and below the front side of the support piece 11. ShapeThe support piece 11 is formed with a small-diameter anti-rotation engagement hole 16 (see FIG. 3(b)), and a second stopper portion 17 is formed on the outer periphery of the insertion hole 13, facing 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 friction 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 the end of the hinge shaft mounting piece 23 in which the rivet insertion hole 22 for the 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 on the end of the angular shaft portion 33 to tighten it. 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 to tighten it.

[0031] Configuration of the 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 on 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 frictional contact portion 51 and which is disposed opposite the second surface of the disc portion 12 of the first bracket 10, and a frictional contact portion 18, the second surface of which forms a frictional contact portion of the disc portion 12. The frictional contact portion 51 of the friction plate 52 and the frictional 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. The free stop portion 50 further has a frictional contact portion 19 formed on the first surface of the disc portion 12 and a frictional contact portion (not shown) formed on the second surface of the flange 31 of the hinge shaft 30, which is in frictional contact with the frictional contact portion 19. The friction plate 52 has an engagement hole 53 in its center that is 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 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 friction torque. As the second housing 3 moves from the closed position toward the opening direction, the rotational biasing mechanism 60 leaves the initial opening operation region in which the pressure applied by the disc spring portion 40 gradually increases, 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 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 from 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 thereof, a first rotating cam washer 62 (see Figs. 7 and 8) disposed on the right side (first surface side) of the fixed cam washer 61 in the drawings, and a second rotating cam washer 63 (see Figs. 9 and 10) disposed on the left side (second surface side) of the fixed cam washer 61 in the drawings.

[0037] In the rotational biasing mechanism 60, the first rotating cam washer 62 and the second rotating cam washer 63, which rotate integrally with the hinge shaft 30, are brought into pressurized contact with the first cam recess 64A and the 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 from the closed position to the open direction, the first rotating cam washer 62 and the second rotating cam washer 63 rotate, and the crests of their cam protrusions slide over the surfaces of the valleys of their cam recesses, climbing against the elastic force of the disc spring 40. In this process, the first opposing distance L1 (not shown) between the fixed cam washer 61 and the first rotating cam washer 62 increases along the X-axis, and similarly, the second opposing distance L2 (not shown) between the fixed cam washer 61 and the second rotating cam washer 63 increases. As the crests of the cam protrusions begin 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 reaches its maximum when (or just before) it reaches the top. This maximum rotational torque is called break-out 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 compresses the disc spring portion 40, which is made up of multiple disc springs (compression springs), along the X-axis direction, thereby increasing the elastic force. The free stop portion 50 sets the elastic force generated by the multiple disc springs 41 being compressed by the third opposing distance L3 as an appropriate elastic force.

[0040] As described above, the rotational biasing mechanism 60 has an initial opening operation region, which is a predetermined angular range between the closed position and the operation start end of the free stop operation region. This region remains unchanged 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. As will be described in detail later, the initial opening operation region is set by the angular range in the circumferential direction of the valleys, which will be described later, provided in each of the cam recesses of the first cam recess 64A and the second cam recess 64B of the fixed cam washer 61. 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 valleys is larger than when 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 valleys can be made smaller. As a result, when the second housing 3 begins to open from the closed position, the rotational torque applied to each of the first rotating cam washer 62 and the second rotating cam washer 63 is reduced. Therefore, 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 is applied to the hinge shaft 30, and the breakaway torque is smaller than when only one first rotating cam washer 62 is used.

[0042] In addition, the timing at which the cam protrusions of the first rotating cam washer 62 and the second rotating cam washer 63 disengage from the cam recesses of the fixed cam washer 61 is staggered 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 set of rotational biasing cam portions, and the second cam recess 64B and the second rotating cam washer 63 form a set of rotational biasing cam portions.

[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 the 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-preventing engagement hole 16 formed in the support piece 11 of the first bracket 10, and engages the fixed cam washer 61 so as to be non-rotatable around the axis of the hinge shaft 30. The center of the insertion hole 65 is designated as 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 direction from front to back 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 the 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 vertically symmetrical about 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 has a first outer cam recess 68A, which forms a cam portion with a flat sector-shaped depression as a cam-shaped portion in part of the first concave flat cam portion 67A, formed on the outer periphery of the fixed cam washer body 64, and a first inner cam recess 69A 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 sandwiched between them. In the following description, the position directly above the Z axis is 12 o'clock on a clock face, and the position directly below is 6 o'clock.

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

[0048] The first outer cam recess 68A is formed with a radius r1 extending radially inward from the outer peripheral edge of the fixed cam washer body 64, and the first inner cam recess 69A is formed with a radius r2 extending radially outward from the inner peripheral 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 first outer cam recess 68A and the first inner cam recess 69A formed on the first surface side in the opening direction and a straight line L12 connecting the ends of the first outer cam recess 68A and the first inner cam recess 69A in the closing direction intersect at a center C, and the diagonal at the intersection is the first sector angle, which is 2α.

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

[0051] A third valley portion 691a with an inclined surface is formed at one circumferential end side (opening direction) of second bottom portion 69a, and a fourth valley portion 692a with an inclined surface is formed at the other circumferential end side (closing direction). The boundary between second bottom portion 69a and third valley portion 691a is indicated as third recessed boundary portion 693a, and the boundary between second bottom portion 69a and fourth valley portion 692a is indicated as 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 the 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 Figure 6(b), second cam recess 64B on the second surface side has second outer cam recess 68B and second inner cam recess 69B, which are cam portions with a flat sector-shaped depression, formed in a part of second concave flat cam portion 67B around center C. Second outer cam recess 68B is formed at the 6 o'clock position, and second inner cam recess 69B is formed at the 12 o'clock position, with first outer cam recess 68A and first inner cam recess 69A shown in Figure 6(a) being 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 portion 691b of an inclined surface is formed on one circumferential end side (opening direction) of the fourth bottom portion 69b constituting the second inner cam recessed portion 69B, and an eighth valley portion 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 the center C, and the diagonal at the intersection is 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 683b and the seventh recessed boundary 693b and a straight line L18 connecting the sixth recessed boundary 684b and the eighth recessed boundary 694b intersect at the center C, and the diagonal at the intersection is the fourth sector angle, which is 2β, an angle 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 angle 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 area (second and fourth sector angle 2β) and shape (depth) of the first outer cam recess 68A and the second inner cam recess 69B in the circumferential direction (range of 0° to 360°). No. 2 The area (first and third sector angles 2α) and shape (depth) of the outer cam recess 68B in the circumferential direction (range of 0° to 360°) are shown. The thickness of the fixed cam washer body 64 is denoted by 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 range of 2β, and on both sides of the second bottom 69a in the circumferential direction, a third valley 691a and a fourth valley 692a are formed, which form inclined surfaces within a predetermined sector 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 sides of the second bottom 69a in the circumferential direction, 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 rotary cam washer 62 will be described with reference to FIGS.

[0062] The first rotating cam washer 62 having a first cam protrusion has a first engagement hole 71A, which is a rectangular hole whose inner shape matches the outer shape of the angular shaft portion 33 of the hinge shaft 30, formed in the axial center of the first rotating cam washer body 70A. The first rotating cam washer body 70A has the same outer diameter as the fixed cam washer body 64 of the fixed cam washer 61. As shown in FIGS. 8(a) and 8(b), the first engagement hole 71A has a long side 71C of its inner diameter surface formed along the Z-axis direction and a short side 71D of its 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 a 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), first cam protrusion 72A has first outer cam protrusion 74A and first inner cam protrusion 75A, which are cam-shaped portions formed on part of first convex flat cam portion 73A, which has a flat outer surface, and which protrude leftward along the X-axis direction. First cam protrusion 72A comes into pressure contact with first cam recess 64A by the elastic force of disc spring portion 40.

[0064] In the Z-Y plane, the first cam protrusion 72A has a first outer cam protrusion 74A formed at a radius r3 radially inward from the outer peripheral edge of the first rotating cam washer body 70A, and a first inner cam protrusion 75A formed at a radius r4 radially outward from the inner peripheral edge of the first engagement hole 71A. 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 at 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 The radius r3 is longer than the radius r4.

[0065] A line L19 connecting the opening end of the first outer cam protrusion 74A and the first inner cam protrusion 75A and a line L20 connecting the closing end 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, with first and second apexes 76a and 77a formed as flat top surfaces at their circumferential centers. In FIG. 8(b), the counterclockwise direction around center C is the opening direction, and the clockwise direction is the closing direction. A first peak 781a with an inclined surface is formed on one circumferential end (opening direction) of the first peak 76a of the first outer cam protrusion 74A, and a second peak 782a with an inclined surface is formed on the other circumferential end (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 with an inclined surface formed on one circumferential end side (opening direction) of the second peak 77a, and a fourth peak 792a with an inclined surface formed on the other circumferential end side (closing direction). The boundary between the second peak 77a and the third peak 791a is indicated by a third convex boundary 793a, and the boundary between the second peak 77a and the fourth peak 792a is indicated by 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 are 794a A straight line L22 connecting these two points intersects at the center C, and the diagonal angle 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] 8(c) shows the circumferential sector-shaped area (sector angle 2γ) and shape (height) of the first outer cam protrusion 74A and the first inner cam protrusion 75A on the thickness-wise upper surface of the first rotating cam washer body 70A. As shown in FIG. 8(b), the starting point of the angle of 0° is the 12 o'clock position on the Z axis, and the angle increases in the counterclockwise direction. The first peak 76a and the second peak 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 on both sides thereof, the first peak 781a, the second peak 782a, the third peak 791a, and the fourth peak 792a are formed 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 closed position, the first outer cam protrusion 74A of the first rotating cam washer 62 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. The angle range (α-δ) that is the difference between the angle α that is half the first sector angle (third sector angle) 2α and the angle δ that is half the sixth sector angle 2δ is the 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 40 prevents the door from opening.

[0071] Second cam protrusion 72B The configuration of the second rotary 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, a rectangular hole whose inner shape matches the outer shape of the angular shaft portion 33 of the hinge shaft 30, formed in the axial center of the second rotating cam washer body 70B. 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. FIGS. 9(a) and 10(a) show the first surface side of the second rotating cam washer body 70B, while FIGS. 9(b) and 10(b) show the second surface side of the second rotating cam washer body 70B. In FIGS. 10(a) and 10(b), Z1 is an inclined axis that passes through the center C and has an inclination angle θ with respect to the Z axis. The second engagement hole 71B has a long side 71C of its inner diameter surface that is parallel to the inclined axis Z1, and a short side 71D of the inner diameter surface that is 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 peripheral 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 clockwise 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), 9(c), and 10(a), a 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), 9(b), and 10(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] Second cam protrusion 72B has second outer cam protrusion 74B and second inner cam protrusion 75B, which are cam-shaped portions formed on part of second convex flat cam portion 73B, which has a flat outer surface, and which protrude toward the right along the X-axis direction. Second cam protrusion 72B is in pressure contact with second cam recess 64B by the elastic force of 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 peripheral 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 peripheral 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 of is formed symmetrically in the front-to-back direction (left-to-right direction on the paper) around the Z axis.

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

[0078] Here, the boundary between the third peak 76b and the fifth mountain 781b is indicated as a fifth convex boundary 783b, the boundary between the third peak 76b and the sixth mountain 782b is indicated as a sixth convex boundary 784b, the boundary between the fourth peak 77b and the seventh mountain 791b is indicated as a seventh convex boundary 793b, and the boundary between the fourth peak 77b and the eighth mountain 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 their opening directions 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 their opening directions 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 783b and the seventh convex boundary 793b and a straight line L26 connecting the sixth convex boundary 784b and the eighth convex boundary 794b intersect at the center C, and the diagonal at the intersection is the eighth sector angle, which is 2δ.

[0081] FIG. 10(c) shows the circumferential area (sector angle 2γ) and shape (height) of the second outer cam protrusion 74B and the second inner cam protrusion 75B on the thickness-wise upper surface 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 peak 76b and the fourth peak 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 on both sides thereof, a fifth peak 781b, a sixth peak 782b, a seventh peak 791b, and an eighth peak 792b are formed 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 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 that engages 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 rotation cam washer 62 has a first engagement hole 71A that engages with the square shaft portion 33 of the hinge shaft 30, and the second rotation cam washer 63 has a second engagement hole 71B that engages with the square shaft portion 33 of the hinge shaft 30, so that the first rotation 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 explained 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), when the second housing 3 is closed relative to the first housing 2 in the closed position, 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 located 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 peak 76a of the first outer cam protrusion 74A and the second peak 77a of the first inner cam protrusion 75A are located 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 against the first outer cam recess 68A of the first cam recess 64A so as to overlap, and the first inner cam protrusion 75A abuts against the first inner cam recess 69A so as to overlap. In the closed position, the overlapping state is symmetrical in the front-to-rear direction (left-to-right direction on the paper) around 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. Furthermore, 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 crest 781a abuts the first convex boundary 783a of the first outer cam protrusion 74A so that it is located on the slope of the first valley 681a that constitutes the first outer cam recess 68A. Similarly, the second crest 782a abuts the second convex boundary 784a so that it is located on the slope of the second valley 682a. Furthermore, the third convex boundary 793a of the first inner cam protrusion 75A is located on the slope of the third valley 691a that constitutes the first inner cam recess 69A so that the third crest 791a abuts, and the fourth convex boundary 794a is located on the slope of the fourth valley 692a so that the fourth crest 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 apex 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 apex 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 urged 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 to the second housing 3 in the closing direction when it is in the closed position, preventing the mouth from opening.

[0088] When the second housing 3 is initially opened 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 this time, the first peak 781a and the third peak 791a on the opening direction side of the first rotating cam washer 62 slide and move up the slopes of the first valley 681a and the third valley 691a. 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, where the peak and valley 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 portion overcomes the first click valley portion and the sliding movement ends, the first rotating cam washer 62 transitions to a free stop region where the first peak portion 76a and the second peak portion 77a abut and 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 portion overcomes the first click valley portion is greater than the rotational torque after transitioning to the free stop region, because the first click peak portion climbs while sliding circumferentially on the slope of the first click valley portion.

[0090] When the first click lobe contacts 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 lobe. The frictional rotation torque required for the free stop portion 50 depends on the elastic force of the disc spring portion 40, and is dependent on an elastic force (hereinafter referred to as "appropriate elastic force") corresponding to a spring compression amount (hereinafter referred to as "appropriate spring compression amount") twice the length (2h1) of the cam height (h1) of the first click lobe. Therefore, the first rotating cam washer 62 alone cannot provide the appropriate elastic force. Therefore, the first rotating cam washer 62 and the second rotating cam washer 63 are used to obtain the appropriate spring compression amount.

[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 square 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. As a result, the second cam protrusion 72B of the second rotating cam washer 63 is superimposed on the second cam recessed portion 64B with a rotational offset of angle θ in the opening direction. Furthermore, the second cam protrusion 72B is positioned offset by angle θ in the opening direction with respect to the first cam protrusion 72A of the first rotating cam washer 62.

[0093] 12(a), when the second housing 3 is closed relative to the first housing 2 in the closed position, the circumferential centers of the third bottom portion 68b of the second outer cam recess portion 68B and the fourth bottom portion 69b of the second inner cam recess portion 69B of the second cam recess portion 64B of the fixed cam washer 61 are set at the 6 o'clock and 12 o'clock positions on the Z axis. In contrast, the second cam protrusion portion 72B of the second rotating cam washer 63 is positioned such that the circumferential centers of the third peak portion 76b of the second outer cam protrusion portion 74B and the fourth peak portion 77b of the second inner cam protrusion portion 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, with an offset of angle θ in the opening direction, and the second inner cam protrusion 75B abuts against the second inner cam recess 69B, with an offset 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. Furthermore, 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, just 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 when 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 offset of angle θ in the opening direction. Here, the fifth crest 781b of the second outer cam protrusion 74B and the seventh crest 791b of the second inner cam protrusion 75B (hereinafter referred to as the second click crest) 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. Because the second click crest climbs the second click valley portion in accordance with 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 the 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 rotary cam washer 62 and the second rotary cam washer 63 are used to reduce the cam height and reduce the breakaway torque, and the offset angle θ is provided to disperse the breakaway torque. In other words, this configuration reduces the rotational torque when the valve is opened.

[0098] First, the reason for lowering the cam height is as follows. The difference between angle α and angle β (α-β) is the area on the plane of first valley portion 681a (third valley portion 691a), as shown in FIG. 11. If an attempt were made to ensure the appropriate elastic force using only the first rotating cam washer 62, the cam depth of first cam recess 64A of fixed cam washer 61 would have to be doubled to 2h1, and the cam height of first cam protrusion 72A of first rotating cam washer 62 would also have to be doubled to 2h1. Because the rotation angle of the first initial opening operation region (α-δ) remains unchanged, the inclination angle of the first click valley portion would increase.

[0099] When the appropriate elastic force is applied to the first rotating cam washer 62 along the X-axis direction, and the cam depth of the first cam recess 64A is set to h1, compared to when it is doubled to 2h1, the greater the inclination angle of the first click valley portion, the greater the escape torque applied to the hinge shaft 30, and therefore the escape torque is smaller when the cam depth of the first cam recess 64A is set to 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 of the first sector angle (third sector angle) 2α, and angle δ, which is half of the eighth sector angle 2δ, minus angle θ, results in an angle (α-δ-θ), which is the second initial opening operation range 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, preventing the mouth from opening with the elastic force of the cup spring portion 40.

[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 click valley of the click recess is climbed up, and then the click crest of the click protrusion of the first rotating cam washer 62 Fixed cam washer 61The click crest of the first rotating cam washer 62 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 and 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 are different, so the generation of break-out torque is dispersed.

[0102] Therefore, in the 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 before, and the opening operation can be performed with one hand.

[0103] Other embodiments

[0104] Contrary to the above embodiment, a first cam protrusion and a second cam protrusion 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 similarly shaped outer cam recess and inner cam recess formed on their outer and inner circumferential portions 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 similarly shaped outer cam protrusion and inner cam protrusion formed on their outer and inner circumferential portions as cam-shaped portions. However, the cam-shaped portions may be combined into one by widening the radial width of either one of the pair of outer cam recess and inner cam recess. [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: First 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: First 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 forms a main body of an electronic device and a second housing that forms 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 rotational biasing mechanism is provided adjacent to the friction torque generating mechanism and biases the first and second housings to rotate 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 first bracket or the second bracket by the elasticity of the disc spring, the rotating cam washer having cam protrusions that drop into the cam recesses of the fixed cam washer depending on the rotation angle; and by shifting the installation positions of the one cam recess and the other cam protrusion relative to each other in the circumferential direction, the cam protrusions sequentially drop into the cam recesses from a predetermined closing angle of the first housing and the second housing, thereby automatically closing and maintaining the closed state of the first housing and the second housing; 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 during opening.

2. A hinge device that connects a first housing that forms a main body of an electronic device and a second housing that forms 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 rotational biasing mechanism is provided adjacent to the friction torque generating mechanism and biases the first and second housings to rotate in a closing direction from a predetermined closing angle, a rotating cam washer provided on each side of the fixed cam washer by the elastic force of the disc spring, and having cam recesses into which the cam protrusions of the fixed cam washer drop according to the rotation angle; and by shifting the installation positions of one of the cam recesses and one of the cam protrusions relative to each other in the circumferential direction, the cam protrusions sequentially drop into the cam recesses from a predetermined closing angle of the first and second housings, thereby automatically closing and maintaining the closed state of the first and second housings; and when the first and second housings are opened, the cam protrusions sequentially escape from the cam recesses, thereby reducing the rotational torque during opening.

3. The hinge device according to claim 1 or 2, The hinge device is characterized in that the cam recess and cam protrusion provided on the fixed cam washer and each of the rotating cam washers are formed by forming a single cam-shaped portion on the 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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