Hinge device and electronic device using the same

Abstract

The present invention provides a hinge device that can open the cover of the machine body from a closed position with one hand, and an electronic device using the hinge device. The hinge device links a first shell and a second shell to open and close, the first shell constitutes the main body of the electronic device, and the second shell constitutes the cover of the electronic device. The hinge device includes: a first bracket, which is installed on the first shell; a second bracket, which is installed on the second shell; a hinge shaft, which is fixed to either the first bracket or the second bracket and connects the other to rotate; a friction torque generating mechanism, which has a plate spring and a friction washer arranged on the hinge shaft; and a rotation force applying mechanism, which is adjacent to the friction torque generating mechanism, so that the first shell and the second shell are rotated and forced in the closing direction from a specific closing angle.

Description

Technical Field

[0001] The present invention relates to a hinge device and an electronic machine using the hinge device. The hinge device connects a machine body and a cover body with a display to open and close. The hinge device has a rotating force-applying mechanism that can apply pressure toward a closed position when closing the cover body so that the cover body is folded, allowing the cover body to remain in a pressurized state at a closed position relative to the machine body without a gap to prevent opening. At the same time, it has an arbitrary stop function and can maintain the cover body at a desired opening angle through friction. The electronic machine using the hinge device is a notebook computer, a foldable portable terminal, and the like. Background Art

[0002] In electronic devices such as laptop computers, a first housing and a second housing are connected by a hinge device so that they can be opened and closed. The first housing is a cover body with a display, and the second housing is a machine body with a keyboard and other devices. The hinge device includes an arbitrary stop mechanism and a rotation force mechanism. The arbitrary stop mechanism is to keep the first housing open at an arbitrary opening position by friction when the first housing is opened from a closed position relative to the second housing. The rotation force mechanism is to apply pressure to the closed position to close the first housing when the first housing is closed, so that the first housing is pressed against the second housing without a gap relative to the machine body to prevent opening (Japanese Patent Publication No. 2015-48906).

[0003] In the hinge device, the hinge shaft is installed on the first bracket of the first housing and the rotation fulcrum shaft of the second housing, and is connected to the first bracket and rotates together, and the second bracket is installed on the hinge shaft and can rotate freely. The second bracket is provided with friction members on both sides of the axial direction of the bearing part, and the friction members rotate together with the hinge shaft. The pair of friction members clamp and press the bearing part of the second bracket through the pressure of the spring member to form an arbitrary stop mechanism, so when the first bracket and the second bracket rotate relative to each other, a friction torque is generated around the hinge shaft.

[0004] When closing the cover body, i.e., the first shell, if the cover body is pushed in the closing direction to a specific angle near the closing position by hand, the rotary force-applying mechanism will cause the cover body to retract and rotate toward the closing position after the hand is removed, and apply pressure to the second shell to prevent the cover body from being in an open state like an open mouth relative to the machine body. The structure of the rotary force-applying mechanism causes the cam concave component and the cam convex component to contact each other through the pressure of the spring component, and converts the relative rotation of the cam concave component and the cam convex component around the axis of the hinge shaft into an increase or decrease in the opposing distance between the cam concave component and the cam convex component along the axial direction of the hinge shaft. The cam concave component has a cam concave portion, which clamps a flat valley bottom to form an inclined valley portion on both sides in the circumferential direction; the cam convex component has a cam convex portion, which forms an inclined mountain portion on both sides in the circumferential direction of the flat top. The cam convex portion falls into the cam concave portion in the closed position, so that the two mountain portions of the cam convex portion are pressed and contacted with the two valley portions of the cam concave portion to form a cam engagement state. When the male cam plate rotates toward the closed position and causes the cam lobes to fall into the cam recesses, a so-called click feeling is obtained.

[0005] On the other hand, when the cover body, i.e., the first housing, is opened from the closed position, an initial opening operation is generally performed, that is, the first housing, which was originally kept in a pressurized state by applying pressure in the closed position to prevent opening, is opened in the opening direction by holding it with one hand. In this case, when the convex cam plate rotates in the closing direction, the mountain portion of the cam convex portion will be stuck on the valley portion of the cam concave portion, so that the convex cam plate can move against the spring force of the spring member and expand the distance between it and the fixed cam washer. During the initial opening operation, the area where the mountain portion of the cam convex portion slides across the valley portion of the cam concave portion is called the initial opening operation area. Through the initial opening operation, the rotational torque required to cross the initial opening operation area increases as the initial opening operation area ends, and its rotational torque is the maximum at the moment before crossing, and this rotational torque is called the disengagement torque. After the initial opening operation ends, the flat top of the cam convex portion will pressurize and contact the flat surface of the fixed cam washer, so the torque applied to the cover body is no longer controlled by the disengagement torque, but is transferred to the control of the friction torque of the arbitrary stop mechanism.

[0006] In the above-mentioned known hinge device, the friction torque of the arbitrary stop mechanism enables the operator of the electronic device to operate the opening and closing of the cover body with one hand, and can determine the friction value of the stop at the position after the hand is removed, which is closely related to the pressure of the spring member and the friction coefficient of the friction member. In addition, the disengagement torque is also closely related to the pressure of the spring member, the inclination angle of the valley of the cam concave part, and the friction coefficient of the sliding surface between the valley and the mountain of the cam convex part. Although the opening can be prevented by increasing the inclination angle of the valley, the disengagement torque will also increase, making the disengagement torque larger than the friction rotation torque of the arbitrary stop mechanism.

[0007] However, if the disengagement torque is greater than the frictional rotation torque of any stop mechanism, when one wants to open the cover portion held in the closed position with one hand, the machine body side may be lifted up at the same time, resulting in a situation where both hands are required to perform the opening operation. Summary of the invention

[0008] The object of the present invention is to provide a hinge device which can open the cover of the machine body from the closed position by one hand and an electronic machine using the hinge device.

[0009] To achieve the above-mentioned purpose, the hinge device of the present invention links a first housing and a second housing to open and close, the first housing constituting the main body of the electronic device, the second housing constituting the cover of the electronic device, and the hinge device comprises: a first bracket, a second bracket, a hinge shaft, a friction torque generating mechanism, and a rotation force applying mechanism. The first bracket is mounted on the first housing; the second bracket is mounted on the second housing; the hinge shaft is fixed to one of the first bracket and the second bracket and connected to the other for rotation; the friction torque generating mechanism has a plate spring and a friction washer arranged on the hinge shaft; the rotation force applying mechanism is adjacent to the friction torque generating mechanism, so that the first housing and the second housing are rotated and forced in the closing direction from a specific closing angle. The rotation force mechanism includes a fixed cam washer and a rotating cam washer. The fixed cam washer is arranged on the hinge shaft and rotates, and is engaged with either the first bracket or the second bracket, and has cam recesses in the circumferential direction of both sides. The rotating cam washer is respectively arranged on both sides of the fixed cam washer and is crimped by the elastic force of the plate spring. The rotating cam washer has a cam protrusion, and the cam protrusion falls into each cam recess of the fixed cam washer according to its rotation angle. By staggering the cam recesses or the cam protrusions in the circumferential direction, when each cam protrusion falls into each cam recess in sequence, the first housing and the second housing will automatically close from a specific closing angle and maintain a mutually closed state; and when the first housing and the second housing are opened, each cam protrusion is separated from the cam recess in sequence, so that the rotation torque during opening can be alleviated.

[0010] To achieve the above-mentioned purpose, the hinge device of the present invention links a first housing and a second housing to open and close, the first housing constituting the main body of the electronic device, the second housing constituting the cover of the electronic device, and the hinge device comprises: a first bracket, a second bracket, a hinge shaft, a friction torque generating mechanism, and a rotation force applying mechanism. The first bracket is mounted on the first housing; the second bracket is mounted on the second housing; the hinge shaft is fixed to one of the first bracket and the second bracket and connects the other to rotate; the friction torque generating mechanism has a plate spring and a friction washer arranged on the hinge shaft; the rotation force applying mechanism is adjacent to the friction torque generating mechanism, so that the first housing and the second housing are rotated and forced in the closing direction from a specific closing angle. The rotation force mechanism includes a fixed cam washer and a rotating cam washer. The fixed cam washer is arranged on the hinge shaft so as to be rotatable, connected to either the first bracket or the second bracket, and has cam convex parts in the circumferential direction of both sides. The rotating cam washers are arranged on both sides of the fixed cam washer and are pressed by the elastic force of the plate spring. The rotating cam washer has a cam recess. Each cam convex part of the fixed cam washer falls into the cam recess according to its rotation angle. By staggering the cam recess or the cam convex part in the circumferential direction, when each cam convex part falls into each cam recess in sequence, the first housing and the second housing will automatically close from a specific closing angle and maintain a mutually closed state; and when the first housing and the second housing are opened, each cam convex part sequentially disengages from the cam recess to alleviate the rotation torque during opening.

[0011] To achieve the above object, in the hinge device described above, the cam recess and cam protrusion provided on the fixed cam washer and each rotating cam washer form a cam-shaped portion on the surface of the cam plate body in the shape of a circular plate.

[0012] To achieve the above object, the electronic device of the present invention is equipped with the hinge device described above, and the first bracket and the second bracket of the hinge device are installed on the first shell and the second shell of the electronic device.

[0013] The hinge device of the present invention can alleviate the rotation torque during opening, so the second shell closed in the closed position can be opened by one hand, eliminating the trouble of pressing the first shell with the other hand to open it.

[0014] In the hinge device of the present invention, the fixed cam washer and the rotating cam washer can be constructed with a simple structure.

[0015] The electronic device of the present invention can be operated with one hand, for example, the second housing can be opened from a closed position, which is more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figures 1(a) and 1(b) are schematic diagrams of an embodiment of an electronic device using the hinge device of the present invention, wherein Figure 1(a) is a stereoscopic view of the opened state; and Figure 1(b) is an enlarged stereoscopic view of the hinge device on the left side of Figure 1(a).

[0017] Figure 2 is a stereoscopic view of the electronic device shown in Figures 1(a) and 1(b) in a closed state, Figure 2(a) is a stereoscopic view viewed from the bottom; Figure 2(b) is an enlarged stereoscopic view of the left hinge device in Figure 2(a).

[0018] Figure 3 is a schematic diagram of an implementation of the hinge device of the present invention shown in Figures 1(a) and 1(b), Figures 2(a) and 2(b), Figure 3(a) is a stereoscopic view of the open state; Figure 3(b) is a view of the hinge device of Figure 3(a) viewed from the first side; Figure 3(c) is a stereoscopic view of the first bracket of Figure 3(a) viewed from the second side.

[0019] Figure 4 It is an exploded perspective view of the hinge device shown in FIG3 .

[0020] Figure 5 shows the structure Figure 4 5( a ) is a perspective view of a first side surface; FIG. 5( b ) is a perspective view of a second side surface; and FIG. 5( c ) is a side view.

[0021] Figure 6(a) is a front view of the first side of the fixed cam washer shown in Figures 5(a), 5(b) and 5(c); Figure 6(b) is a front view of the second side of the fixed cam washer shown in Figures 5(a), 5(b) and 5(c); Figure 6(c) is a diagram showing the shape (depth) of the second cam recess of the fixed cam washer shown in Figures 5(a), 5(b) and 5(c) and the recess area around the X-axis expressed in angles.

[0022] Figure 7 (a) and Figure 7 (b) show the structure of Figure 4 A schematic diagram of a first rotating cam washer of the hinge device is shown, wherein FIG7( a ) is a stereoscopic view of a first side surface; and FIG7( b ) is a stereoscopic view of a second side surface.

[0023] Figure 8(a) is a front view of the first side surface of the first rotating cam washer shown in Figures 7(a) and 7(b); Figure 8(b) is a front view of the first cam protrusion formed on the second side surface of the first rotating cam washer shown in Figures 7(a) and 7(b); Figure 8(c) is a diagram showing the shape (height) of the first rotating cam washer shown in Figures 7(a) and 7(b) and the outer protrusion and inner protrusion areas around the X-axis expressed in angles.

[0024] Figure 9 shows the structure Figure 49( a ) is a perspective view of the first side surface; FIG. 9( b ) is a perspective view of the second side surface; and FIG. 9( c ) is a side view.

[0025] Figure 10(a) is a front view of the second cam protrusion formed on the first side surface of the second rotating cam washer shown in Figures 9(a), 9(b) and 9(c); Figure 10(b) is a front view of the second side surface of the second rotating cam washer shown in Figures 9(a), 9(b) and 9(c); Figure 10(c) is a diagram showing the shape (height) of the second rotating cam washer shown in Figures 9(a), 9(b) and 9(c) and the outer protrusion and inner protrusion areas around the X-axis in terms of angles.

[0026] FIG. 11 is an explanatory diagram of the positional relationship between the first cam recess and the first cam protrusion in the closed position, FIG. 11( a ) represents the first cam recess; FIG. 11( b ) represents the first cam protrusion.

[0027] FIG. 12 is a diagram illustrating the positional relationship between the second cam recess and the second cam protrusion in the closed position, FIG. 12( a ) shows the second cam recess; FIG. 12( b ) shows the second cam protrusion. DETAILED DESCRIPTION

[0028] The present invention will be described below based on the embodiments shown in the drawings.

[0029] FIG. 1(a) and FIG. 1(b), FIG. 2(a) and FIG. 2(b) illustrate the hinge device of the present invention by taking a notebook computer 1 as an example of an electronic device. In the notebook computer 1, the second housing 3 of the cover body carrying the display is mounted on the first housing 2 of the machine body carrying the keyboard and other devices through its left and right hinge devices 100L and 100R so as to be freely opened and closed. Since the left hinge device 100L and the right hinge device 100R are symmetrical, only the left hinge device 100L will be described below.

[0030] As shown in Figure 3(a), Figure 3(b), Figure 3(c) and Figure 4 As shown, the hinge device 100L includes: a first bracket 10 mounted on the first housing 2; a second bracket 20 mounted on the second housing 3; and a hinge shaft 30 that connects the first bracket 10 and the second bracket 20 so as to rotate relative to each other. In addition, the hinge device 100L includes a plate spring portion 40 composed of a plurality of plate springs as a friction torque generating mechanism, and a first friction washer 91 and a second friction washer 92 as friction plates. Furthermore, the hinge device 100L includes an optional stopper 50 and a rotation urging mechanism 60.

[0031] In order to open the cover body, i.e., the second housing 3, from the closed position, the action of holding the second housing 3, which is originally in the closed position and is kept in a pressurized state to prevent opening by rotating and applying force, in the opening direction with one hand is called the initial opening operation. The function of the arbitrary stop portion 50 is to enable the second housing 3 to be opened and closed by one hand within a specific opening and closing angle range (called the arbitrary stop action area), and at the same time, the second housing 3 can be stopped at the position due to friction after the hand leaves.

[0032] In a specific angle range from the closed position to the starting end of the arbitrary stop action area (called the initial opening operation area), the rotation urging mechanism 60 retracts the second housing 3 to prevent opening. The plate spring portion 40 applies pressure to the arbitrary stop portion 50 and the rotation urging mechanism 60.

[0033] Structure of hinge shaft 30

[0034] like Figure 4 As shown in FIG. 3( b), the hinge shaft 30 is clamped with the flange 31 to form a bracket mounting shaft portion 32 at one end side in the axial direction, and a square shaft portion 33 having a square shaft portion is formed at the other end side. The second bracket 20 is fixed to the bracket mounting shaft portion 32 by a rivet 21. As shown in FIG. 3( b), a first stopper portion 34 in a fan-shaped shape is formed on the outer peripheral end surface of the flange 31 toward the outside in the diameter direction. FIG. 3( b) shows the closed position of the second shell 3, and the abutting surface 34a of the first stopper portion 34 at the front end in the opening direction has a phase difference of 180° in the closing direction with the abutting surface 17a of the second stopper portion 17 formed on the first bracket 10 after the first stopper portion 17 is formed, with the axis of the hinge shaft 30 as the center. Therefore, when the second shell 3 is rotated 180° relative to the first shell 2 from the closed position, the opening of the second shell 3 can be restricted. In other words, the stopper mechanism composed of the first stopper 34 and the second stopper 17 allows the second housing 3 to be opened and closed within the range from the closed position to the horizontal position of the second housing 3 relative to the first housing 2 .

[0035] In addition, the X-axis, Y-axis, and Z-axis are three axes perpendicular to each other, the axial direction of the hinge axis 30 (the left-right direction of the first housing 2) is the X-axis direction, the front-back direction of the first housing 2 is the Y-axis direction, and the up-down direction of the first housing 2 is the Z-axis direction. Figure 1(a) to Figure 3(c) In the figure, the left and right direction of the X-axis direction is the left and right direction, the front and rear direction of the Y-axis direction is the front and rear direction, and the up and down direction of the Z-axis direction is the up and down direction. Then, for the component installed on the hinge shaft 30, the right side surface is the first surface, and the left side surface is the second surface.

[0036] Structure of the first bracket 10

[0037] Figure 4In the embodiment, the first bracket 10 has a support piece 11 extending in the Y-axis direction perpendicular to the axial direction of the hinge shaft 30. The support piece 11 is formed into a rectangular flat plate that is longer in the Y-axis direction, and a circular plate portion 12 is formed at the rear end thereof, constituting a bearing portion that is slightly in the shape of a circular plate. A circular insertion hole 13 is formed on the circular plate portion 12. An upper mounting piece 14 that extends to the right side in the X-axis direction and has a longer side is formed on the upper and lower sides of the front side of the support piece 11. In addition, a rotation stop engagement hole 16 with a small diameter is formed on the support piece 11 (refer to FIG. 3(b)), and a second stopper portion 17 is formed on the outer periphery of the insertion hole 13 toward the right side 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 and is inserted into the flange 31. A circular friction contact portion 18 is formed on the second side surface of the circular plate portion 12 (refer to FIG. 3(c)).

[0038] Configuration of the Second Bracket 20

[0039] Figure 3(a), Figure 3(b), Figure 3(c), Figure 4 In the embodiment, the second bracket 20 is bent from the end of the hinge shaft mounting piece 23 along the X-axis direction to form an elongated housing mounting piece 24. The hinge shaft mounting piece 23 is formed with a rivet insertion hole 22 for the rivet 21.

[0040] The plate-shaped spring portion 40, the optional stop portion 50, the rotation urging mechanism 60, the first friction washer 91, and the second friction washer 92 are inserted through the square shaft portion 33 of the hinge shaft 30, and the nut 93 is locked to the screw portion 33a formed at the end of the square shaft portion 33. The optional stop portion 50, the rotation urging mechanism 60, the first friction washer 91, the plate-shaped spring portion 40, and the second friction washer 92 are sequentially arranged on the square shaft portion 33 from the circular plate portion 12 of the first bracket 10 abutting the flange 31 toward the left side in the X-axis direction, and the nut 93 abuts against the second friction washer 92 to be locked.

[0041] Structure of the plate-shaped spring portion 40

[0042] The plate spring portion 40 is formed by stacking a plurality of (eight in this embodiment) plate springs 41. The plate spring 41 has a circular insertion hole 42 formed at the center. Both ends of the plate spring portion 40 in the left-right direction abut against the first friction washer 91 and the second friction washer 92.

[0043] Configuration of the optional stop portion 50

[0044] The optional stopper 50 includes a friction plate 52 and a friction contact portion 18. The friction plate 52 constitutes a friction contact portion 51, which is a first side surface arranged opposite to the second side surface of the circular plate portion 12 of the first bracket 10; and the friction contact portion 18 is a second side surface constituting the friction contact portion of the circular plate portion 12. The friction contact portion 51 of the friction plate 52 and the friction contact portion 18 of the circular plate portion 12 are in pressurized contact by the elastic force of the plate-shaped spring portion 40. In addition, the optional stopper 50 has a friction contact portion 19 and a friction contact portion not depicted in the figure. The friction contact portion 19 is formed on the first side surface of the circular plate portion 12; the friction contact portion not depicted in the figure is formed on the second side surface of the flange 31 of the hinge shaft 30 and is in friction contact with the friction contact portion 19. A coupling hole 53 is formed in the center of the friction plate 52. The coupling hole 53 has the same shape as the square shaft portion 33 of the hinge shaft 30 and is connected to the hinge shaft 30 as a whole and rotates together. The hinge shaft 30 can rotate freely relative to the insertion hole 13 of the first bracket 10. Therefore, when the second bracket 20 fixed to the hinge shaft 30 rotates relative to the first bracket 10 with the hinge shaft 30 as the center, the friction plate 52 also rotates relative to the circular plate portion 12. At this time, the friction contact portion 51 of the friction plate 52 rotates while frictionally contacting with the friction contact portion 18 of the circular plate portion 12 to generate a friction torque. Similarly, the friction contact portion formed on the flange 31, which is not depicted in the figure, and the friction contact portion 19 of the circular plate portion 12 rotate while frictionally contacting to generate a friction torque. As the second housing 3 moves from the closed position to the opening direction, the rotation force mechanism 60 will be separated from the initial opening operation area where the pressure is gradually increased by the plate-shaped spring portion 40. When the second housing 3 is transferred to the arbitrary stop operation area, a certain elastic force will be given between the circular plate portion 12 of the arbitrary stop portion 50 and the friction plate 52 and the flange 31 to generate a specific friction torque.

[0045] Structure of the rotation urging mechanism 60

[0046] The rotation force applying mechanism 60 is as follows Figure 4 As shown, it is arranged between the first friction washer 91 and the friction plate 52. The rotation urging mechanism 60 is composed of a fixed cam washer 61 (refer to FIGS. 5(a), 5(b), 5(c), 6(a), 6(b), 6(c)), a first rotating cam washer 62 (refer to FIGS. 7(a), 7(b), 8(a), 8(b), 8(c)), and a second rotating cam washer 63 (refer to FIGS. 9(a), 9(b), 9(c), 10(a), 10(b), 10(c)). The fixed cam washer 61 has a first cam recess 64A as a cam recess and a second cam recess 64B as a cam recess formed on both surfaces thereof; the first rotating cam washer 62 is arranged on the right side (first side surface) of the fixed cam washer 61 in the figure; and the second rotating cam washer 63 is arranged on the left side (second side surface) of the fixed cam washer 61 in the figure.

[0047] The rotation urging mechanism 60 uses the elastic force of the plate spring portion 40 to cause the first rotating cam washer 62 and the second rotating cam washer 63 that rotate integrally with the hinge shaft 30 to contact and press the first cam recess 64A and the second cam recess 64B of the fixed cam washer 61 .

[0048] 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 mountain portions of their respective cam protrusions slide on the surface of the valley portion of the cam recess and climb up against the elastic force of the plate-shaped spring portion 40. At this time, the first opposing distance L1 (not depicted in the figure) between the fixed cam washer 61 and the first rotating cam washer 62 along the X-axis direction will be expanded, and similarly, the second opposing distance L2 (not depicted in the figure) between the fixed cam washer 61 and the second rotating cam washer 63 will also be expanded. As the mountain portion of the cam protrusion begins to climb up the valley portion of the cam protrusion, the rotational torque applied to the second housing 3 will increase, and the rotational torque applied to the second housing 3 will be maximum when the climbing is completed (close to the completion of the climbing). The maximum rotational torque at this time is called the disengagement torque.

[0049] The sum of the first facing distance L1 and the second facing distance L2 is the third facing distance L3 (not shown in the figure), at which time the plate-shaped spring portion 40 composed of a plurality of plate-shaped springs (pushing springs) is shortened in length along the X-axis direction, so that the elastic force becomes larger. The elastic force generated by the arbitrary stop portion 50 compressing the plurality of plate-shaped springs 41 by the third facing distance L3 is set to an appropriate elastic force.

[0050] As described above, the rotation force applying mechanism 60, in a specific angle range between the closed position and the action start end of the arbitrary stop action area, that is, in the initial opening operation area, for example, if only one first rotating cam washer 62 is used, it will be the same as the case where the first rotating cam washer 62 and the second rotating cam washer 63 are used in the present embodiment. As described in detail later, the setting of the initial opening operation area depends on the circumferential angle range of the valley portion described later set on each of the first cam recess 64A and the second cam recess 64B of the fixed cam washer 61. Therefore, taking the case where only one first rotating cam washer 62 is used as an example, in order to obtain an appropriate elastic force, the cam depth of the cam recess and the cam height of the cam convex portion of the first rotating cam washer 62 are the length of the third opposing distance L3 (not shown in the figure).

[0051] In this way, the angle of the valley portion will become larger than when the cam depth is the length of the opposing distances L1 and L2. On the contrary, if the cam depth is the length of the opposing distances L1 and L2, respectively, the angle of the valley portion can be made smaller. As a result, when the second housing 3 begins to open from the closed position, the rotational torque applied to the first rotating cam washer 62 and the second rotating cam washer 63 will become smaller. Therefore, the rotational torque of the first rotating cam washer 62 and the rotational torque of the second rotating cam washer 63 will be added to the hinge shaft 30, so that the disengagement torque is smaller than when only one first rotating cam washer 62 is used.

[0052] In addition, the cam convex portions of the first rotating cam washer 62 and the second rotating cam washer 63 stagger the timing of disengaging from the cam concave portions of the fixed cam washer 61, so that the disengagement torque is dispersed and the disengagement torque concentration is avoided. The first cam concave portion 64A and the first rotating cam washer 62 form a set of rotational force cam portions, and the second cam concave portion 64B and the second rotating cam washer 63 form another set of rotational force cam portions.

[0053] The structure of the fixed cam washer 61 will be described below with reference to FIGS. 5( a ), 5 ( b ), 5 ( c ) and FIGS. 6 ( a ), 6 ( b ), and 6 ( c ).

[0054] As shown in Fig. 5(a), Fig. 5(b) and Fig. 5(c), the fixed cam washer 61 has a circular insertion hole 65 formed in the center of the disc-shaped fixed cam washer body 64, through which the square shaft portion 33 can rotate freely and be inserted. A short arm portion 66 extends radially outward from the outer end of the fixed cam washer body 64, and a coupling pin 66a extends from the first side surface of the arm portion 66 toward the right side in the X-axis direction. The coupling pin 66a is inserted into the rotation stop coupling hole 16 formed on the support plate 11 of the first bracket 10, and the fixed cam washer 61 is coupled around the axis of the hinge shaft 30 so that it cannot rotate. Symbol C is the center of the insertion hole 65.

[0055] As shown in FIG5(a), the first cam recess 64A is formed on the first side surface of the fixed cam washer body 64; as shown in FIG5(b), the second cam recess 64B is formed on the second side surface of the fixed cam washer body 64. In FIG6(a), the axis passing through the engagement pin 66a and the center C in the up-and-down direction of the paper is the Z axis, the axis passing through the center C in the left-and-right direction of the paper is the Y axis, and the axis passing through the center C in the positive and negative directions of the paper is the X axis. In FIG6(a), the left side of the figure is the front side, and the right side is the rear side; in FIG6(b), the left side of the figure is the rear side, and the right side is the front side. In FIG6(a), with the center C as the center point, the clockwise direction is the rotation direction from the closed position to the open direction; in FIG6(b), with the center C as the center point, the counterclockwise direction is the rotation direction from the closed position to the open direction.

[0056] 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 symmetrical with respect to the Y axis. The first surface and the second surface of the fixed cam washer body 64 are formed as a flat first concave plane cam portion 67A and a second concave plane cam portion 67B. The first cam recess 64A is formed with a first outer cam recess 68A on the outer peripheral side of the fixed cam washer body 64. The first outer cam recess 68A constitutes a cam portion having a fan-shaped and concave plane. As a part of the cam shape portion of the first concave plane cam portion 67A, the first inner cam recess 69A is formed on the inner peripheral side of the insertion hole 65. The first outer cam recess 68A and the first inner cam recess 69A are formed in a similar shape with the center C sandwiched therebetween. The following description is made with the position of the clock number 12 being directly above the Z axis and the position of the clock number 6 being directly below.

[0057] 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 shape of the first outer cam recess 68A and the shape of the first inner cam recess 69A are symmetrical in the front-to-back direction (left-right direction of the paper) with the Z axis interposed therebetween, and the first outer cam recess 68A and the first inner cam recess 69A are formed above and below the Y axis as the center.

[0058] The first outer cam recess 68A is formed radially inward from the outer peripheral edge of the fixed cam washer body 64 with a radius r1, and the first inner cam recess 69A is formed radially outward from the inner peripheral edge of the insertion hole 65 with a radius r2. The radius r1 is longer than the radius r2.

[0059] As shown in Figure 6(a), a straight line L11 connects the opening direction ends of the first outer cam recess 68A and the first inner cam recess 69A formed on the first side surface, and a straight line L12 connects the closing direction ends of the first outer cam recess 68A and the first inner cam recess 69A. The straight line L11 intersects the straight line L12 at the center C, and the diagonal angle of the intersection is the first sector angle, and the first sector angle is 2α.

[0060] The first outer cam recess 68A and the first inner cam recess 69A form a flat bottom surface at the center of the circumferential direction, namely, the first bottom 68a and the second bottom 69a. The first bottom 68a forms an inclined surface, i.e., a first valley 681a, on one end side (opening direction) in the circumferential direction, and forms a second valley 682a on the other end side (closing direction). The boundary between the first bottom 68a and the first valley 681a is represented by a first concave boundary 683a, and the boundary between the first bottom 68a and the second valley 682a is represented by a second concave boundary 684a.

[0061] The second bottom 69a forms an inclined surface, the third valley 691a, on one end side (opening direction) in the circumferential direction, and forms an inclined surface, the fourth valley 692a, on the other end side (closing direction). The boundary between the second bottom 69a and the third valley 691a is represented by the third concave boundary 693a, and the boundary between the second bottom 69a and the fourth valley 692a is represented by the fourth concave boundary 694a.

[0062] As shown in Figure 6(a), straight line L13 connects the first concave boundary portion 683a and the third concave boundary portion 693a, and straight line L14 connects the second concave boundary portion 684a and the fourth concave boundary portion 694a. Straight line L13 intersects straight line L14 at center C, and the diagonal angle of the intersection is the second sector angle, and the second sector angle is 2β.

[0063] Next, the structure of the second cam recessed portion 64B will be described.

[0064] As shown in Fig. 6(b), the second cam recess 64B on the second side is formed with the center C as the center in the part of the second concave plane cam portion 67B, and its shape is similar to the cam portion with a fan-shaped and concave plane, that is, similar to the second outer cam recess 68B and the second inner cam recess 69B. 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. The first outer cam recess 68A and the first inner cam recess 69A shown in Fig. 6(a) are arranged up and down oppositely with the Y axis as the center.

[0065] The third bottom portion 68b constituting the second outer cam recessed portion 68B forms a fifth valley portion 681b on one end side (opening direction) in the circumferential direction, and forms a sixth valley portion 682b on the other end side (closing direction) in the circumferential direction. The boundary between the third bottom portion 68b and the fifth valley portion 681b is represented by a fifth concave boundary portion 683b, and the boundary between the third bottom portion 68b and the sixth valley portion 682b is represented by a sixth concave boundary portion 684b.

[0066] The fourth bottom portion 69b constituting the second inner cam recess 69B forms an inclined surface, the seventh valley portion 691b, on one end side (opening direction) in the circumferential direction, and forms an inclined surface, the eighth valley portion 692b, on the other end side (closing direction) in the circumferential direction. The boundary between the fourth bottom portion 69b and the seventh valley portion 691b is represented by the seventh concave boundary portion 693b, and the boundary between the fourth bottom portion 69b and the eighth valley portion 692b is represented by the eighth concave boundary portion 694b.

[0067] As shown in Figure 6(b), straight line L15 connects the various opening directions of the second outer cam recess 68B and the second inner cam recess 69B formed on the second side surface, and straight line L16 connects the various closing directions of the second outer cam recess 68B and the second inner cam recess 69B. Straight line L15 intersects straight line L16 at center C, and the diagonal angle of the intersection is the third sector angle, and the third sector angle is set to 2α which is equal to the first sector angle.

[0068] As shown in Figure 6(b), straight line L17 connects the fifth concave boundary portion 683b and the seventh concave boundary portion 693b, and straight line L18 connects the sixth concave boundary portion 684b and the eighth concave boundary portion 694b. Straight line L17 and straight line L18 intersect at center C, and the diagonal of the intersection is the fourth sector angle. Let the fourth sector angle be 2β, which is equal to the second sector angle.

[0069] In FIG6(c), 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°) are shown above the thickness direction of the fixed cam washer body 64; the area (first and third sector angles 2α) and shape (depth) of the first outer cam recess 68A and the second outer cam recess 68B in the circumferential direction (range of 0° to 360°) are shown below. The thickness of the fixed cam washer body 64 is t.

[0070] As shown in Fig. 6(a) and Fig. 6(b), the starting point of the angle 0° is located at the 12 o'clock position on the Z axis. The first inner cam recess 69A forms a second bottom 69a with a depth of h1 within the range of an angle of 2β, and forms inclined surfaces at a specific fan-shaped angle range (α-β) on both sides of the circumferential direction, namely, the third valley 691a and the fourth valley 692a. The first outer cam recess 68A forms a first bottom 68a with a depth of h1 within the range of an angle of 180°±β, and further forms inclined surfaces at a specific fan-shaped angle (α-β) on both sides of the circumferential direction, namely, the first valley 681a and the second valley 682a. The fourth bottom 69b of the second inner cam recess 69B on the second side has a depth of h1, and the third bottom 68b of the second outer cam recess 68B has a depth of h1. In this embodiment, the first bottom 68a, the second bottom 69a, the third bottom 68b, and the fourth bottom 69b are all the same depth (h1).

[0071] Next, the structure of the first rotating cam washer 62 will be described with reference to FIGS. 7( a ), 7 ( b ) and FIGS. 8 ( a ), 8 ( b ), and 8 ( c ).

[0072] The first rotating cam washer 62 having the first cam protrusion has a first engaging hole 71A having a rectangular shape formed in the center of the shaft of the first rotating cam washer body 70A, and its outer shape is consistent with the square shaft portion 33 of the hinge shaft 30. 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. The first engaging 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 as shown in FIG. 8(a) and FIG. 8(b). The first side surface of the first rotating cam washer body 70A is formed as a flat surface as shown in FIG. 7(a) and FIG. 8(a), and the second side surface has a first cam protrusion 72A formed as shown in FIG. 7(b) and FIG. 8(b).

[0073] As shown in Fig. 7(b) and Fig. 8(b), the first cam protrusion 72A forms a cam-shaped portion protruding to the left along the X-axis direction, namely, a first outer cam protrusion 74A and a first inner cam protrusion 75A, at a portion of the first convex plane cam portion 73A having a flat outer surface. The first cam protrusion 72A is pressed into contact with the first cam recess 64A by the elastic force of the plate-shaped spring portion 40.

[0074] On the ZY plane, the first cam protrusion 72A forms a first outer cam protrusion 74A from the outer peripheral edge of the first rotating cam washer body 70A toward the inside in the diameter direction with a radius r3; and forms a first inner cam protrusion 75A from the inner peripheral edge of the first engaging hole 71A toward the outside in the diameter direction with a radius r4. The first outer cam protrusion 74A and the first inner cam protrusion 75A are formed in a similar shape with the center C of the first engaging 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 with the Y axis sandwiched therebetween, and their respective shapes are symmetrical in the front-to-back direction (left-right direction on the paper) with the Z axis as the center. The radius r3 is longer than the radius r4.

[0075] A straight line L19 connects the opening direction ends of the first outer cam protrusion 74A and the first inner cam protrusion 75A, and a straight line L20 connects the closing direction ends of the first outer cam protrusion 74A and the first inner cam protrusion 75A. The straight line L19 and the straight line L20 intersect at the center C, and the diagonal angle of the intersection is the fifth sector angle, and the fifth sector angle is 2γ. The fifth sector angle 2γ is larger than the first and third sector angles 2α.

[0076] As shown in FIG8(b), the first outer cam convex portion 74A and the first inner cam convex portion 75A are formed into a convex shape along the circumferential direction, and a flat top surface is formed in the center of the circumferential direction, namely, the first top portion 76a and the second top portion 77a. In FIG8(b), with the center C as the center, the counterclockwise direction is the opening direction, and the clockwise direction is the closing direction. The first top portion 76a of the first outer cam convex portion 74A forms an inclined surface - the first mountain portion 781a at one end side (opening direction) in the circumferential direction, and forms an inclined surface - the second mountain portion 782a at the other end side (closing direction). The boundary between the first top portion 76a and the first mountain portion 781a is represented by the first convex boundary portion 783a, and the boundary between the first top portion 76a and the second mountain portion 782a is represented by the second convex boundary portion 784a.

[0077] The second top 77a of the first inner cam convex portion 75A forms an inclined surface, the third ridge 791a, at one end side (opening direction) in the circumferential direction, and forms an inclined surface, the fourth ridge 792a, at the other end side (closing direction). The boundary between the second top 77a and the third ridge 791a is represented by the third convex boundary 793a, and the boundary between the second top 77a and the fourth ridge 792a is represented by the fourth convex boundary 794a.

[0078] The straight line L21 connects the first convex boundary portion 783a and the third convex boundary portion 793a, and the straight line L22 connects the second convex boundary portion 784a and the fourth convex boundary portion 794a. The straight line L21 and the straight line L22 intersect at the center C, and the diagonal angle of the intersection is the sixth sector angle, and the sixth sector angle is 2δ. The sixth sector angle 2δ is larger than the second and fourth sector angles 2β.

[0079] In FIG8(c), the fan-shaped area (fan angle 2γ) and shape (height) of the first outer cam protrusion 74A and the first inner cam protrusion 75A in the circumferential direction are shown above the thickness direction of the first rotating cam washer body 70A. As shown in FIG8(b), the starting point of the angle 0° is at the 12 o'clock position on the Z axis, and the angle gradually increases in the counterclockwise direction. The top surface of the first top 76a and the second top 77a of the first outer cam protrusion 74A and the first inner cam protrusion 75A is formed as a flat surface with a height of h1, and the first mountain 781a and the second mountain 782a, the third mountain 791a and the fourth mountain 792a are formed on both sides with a specific fan angle range (γ-δ). In this embodiment, the height of the first top 76a and the second top 77a is h1, which is equal to the depth (h1) of the first bottom 68a and the second bottom 69a.

[0080] When the first rotating cam washer 62 is in the closed position, the first outer cam protrusion 74A is opposite to the first outer cam recess 68A of the first cam recess 64A, and the first inner cam protrusion 75A is opposite to the first inner cam recess 69A of the first cam recess 64A. In addition, the angle range difference (α-δ) between the half angle α of the first sector angle (third sector angle) 2α and the half angle δ of the sixth sector angle 2δ belongs to the first initial opening operation area in the relationship between the first rotating cam washer 62 and the first cam recess 64A, which closes the second housing 3 toward the first housing 2 and prevents opening by the elastic force of the plate spring portion 40.

[0081] The structure of the second rotating cam washer 63 having the second cam protrusion 72B will be described below with reference to FIGS. 9( a ), 9 ( b ), 9 ( c ) and 10 ( a ), 10 ( b ), 10 ( c ).

[0082] The second rotating cam washer 63 forms a second engaging hole 71B having a rectangular shape in the hole at the axial center of the second rotating cam washer body 70B, and its outer shape is consistent with the square 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. FIG. 9(a) and FIG. 10(a) show the first side surface of the second rotating cam washer body 70B, and FIG. 9(b) and FIG. 10(b) show the second side surface of the second rotating cam washer body 70B. In FIG. 10(a) and FIG. 10(b), the inclined axis passing through the center C and having an inclination angle θ with the Z axis is Z1. The long side 71C of the inner diameter surface of the second engaging hole 71B is parallel to the inclined axis Z1, and the short side 71D of the inner diameter surface is perpendicular to the long side 71C. As shown in FIGS. 9( a ), 9 ( c ) and 10 ( a ), 10 ( b ), and 10 ( c ), the symbol 71E indicating the Z-axis position on the outer circumferential surface of the second rotating cam washer body 70B is located at the 12 o'clock position on the Z-axis.

[0083] The rotation direction from the closed position to the open direction of the second rotating cam washer 63 is clockwise when viewed from the first side surface shown in FIG. 10( a ), and the tilt axis Z1 is tilted counterclockwise at an angle θ relative to the Z axis.

[0084] As shown in Fig. 9(a), Fig. 9(c) and Fig. 10(a), the second cam protrusion 72B is formed on the first side surface of the second rotating cam washer body 70B. As shown in Fig. 9(b), Fig. 10(b) and Fig. 10(c), the second side surface of the second rotating cam washer body 70B is formed as a flat surface. The second cam protrusion 72B is formed in the same manner as the first cam protrusion 72A on the ZY plane.

[0085] The second cam protrusion 72B forms a cam-shaped portion protruding to the right along the X-axis direction, namely, a second outer cam protrusion 74B and a second inner cam protrusion 75B, at a portion of the second convex plane cam portion 73B having a flat outer surface. The second cam protrusion 72B is pressed into contact with the second cam recess 64B by the elastic force of the plate-shaped spring portion 40.

[0086] In the ZY plane, the second cam protrusion 72B forms a second outer cam protrusion 74B from the outer peripheral edge of the second rotating cam washer body 70B toward the inner side in the diameter direction with a radius r3; and forms a second inner cam protrusion 75B from the inner peripheral edge of the second engagement hole 71B toward the outer side in the diameter direction with a radius r4. 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 with the Y axis sandwiched therebetween, and the shapes of the second outer cam protrusion 74B and the second inner cam protrusion 75B are symmetrical in the front-to-back direction (left-right direction of the paper) with the Z axis as the center.

[0087] The third top 76b of the second outer cam convex portion 74B forms an inclined surface, namely the fifth peak 781b, at one end side in the circumferential direction (opening direction), and forms an inclined surface, namely the sixth peak 782b, at the other end side in the circumferential direction (closing direction). On the other hand, the fourth top 77b of the second inner cam convex portion 75B forms an inclined surface, namely the seventh peak 791b, at one end side in the circumferential direction (opening direction), and forms an inclined surface, namely the eighth peak 792b, at the other end side in the circumferential direction (closing direction).

[0088] The boundary between the third top 76b and the fifth mountain portion 781b is represented by the fifth convex boundary portion 783b, and the boundary between the third top 76b and the sixth mountain portion 782b is represented by the sixth convex boundary portion 784b. In addition, the boundary between the fourth top 77b and the seventh mountain portion 791b is represented by the seventh convex boundary portion 793b, and the boundary between the fourth top 77b and the eighth mountain portion 792b is represented by the eighth convex boundary portion 794b.

[0089] Straight line L23 connects each opening direction end of the second outer cam lobe 74B and the second inner cam lobe 75B, straight line L24 connects each opening direction end of the second outer cam lobe 74B and the second inner cam lobe 75B, straight line L23 intersects straight line L24 at center C, and the diagonal angle of the intersection is the seventh sector angle, and the seventh sector angle is 2γ.

[0090] Straight line L25 connects the fifth convex boundary portion 783b and the seventh convex boundary portion 793b, and connects the sixth convex boundary portion 784b and the eighth convex boundary portion 794b. Straight line L25 intersects straight line L26 at center C, and the diagonal of the intersection is the eighth sector angle. Let the eighth sector angle be 2δ.

[0091] In FIG. 10(C), the area (sector angle 2γ) and shape (height) of the second outer cam convex portion 74B and the second inner cam convex portion 75B in the circumferential direction are shown above the thickness direction of the second rotating cam washer body 70B. Furthermore, as shown in FIG. 10(a), the 12 o'clock position on the Z axis is the starting point of the angle 0°. The top surfaces of the third top 76b and the fourth top 77b of the second outer cam convex portion 74B and the second inner cam convex portion 75B are formed as flat surfaces with a height of h1, and the fifth mountain portion 781b, the sixth mountain portion 782b, the seventh mountain portion 791b, and the eighth mountain portion 792b are formed on both sides in a specific sector angle range (γ-δ). In this embodiment, the height of the third top 76b and the fourth top 77b is set to h1, which is the same as the depth (h1) of the third bottom 68b and the fourth bottom 69b.

[0092] In the hinge device 100L of this embodiment, the hinge shaft 30 is supported by the insertion hole 13 of the first bracket 10 so as to be freely rotatable, and is integrally connected to the second bracket 20 and rotates together. In the fixed cam washer 61, the engagement pin 66a is engaged with the rotation stop engagement hole 16 of the first bracket 10, and the hinge shaft 30 is inserted into the insertion hole 65 so as to be freely rotatable. The first engagement hole 71A of the first rotating cam washer 62 is engaged with the square shaft portion 33 of the hinge shaft 30, and the second engagement hole 71B of the second rotating cam washer 63 is engaged with the square shaft portion 33 of the hinge shaft 30, so that the hinge shaft 30 is integrally connected to the hinge shaft 30 and rotates together.

[0093] Next, 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(a) and Fig. 11(b). For the convenience of description, Fig. 11(a) and Fig. 11(b) show the state viewed from the first side surface, while Fig. 11(b) shows the first cam protrusion 72A formed on the second side surface in a perspective state and is indicated by a solid line.

[0094] In the state where the second housing 3 is closed in the closed position relative to the first housing 2, the first cam recess 64A of the fixed cam washer 61 has the first bottom 68a of the first outer cam recess 68A and the second bottom 69a of the first inner cam recess 69A located at the 12 o'clock and 6 o'clock positions on the Z axis, as shown in FIG. 11(a). In contrast, in the first cam protrusion 72A of the first rotating cam washer 62, the first top 76a of the first outer cam protrusion 74A and the second top 77a of the first inner cam protrusion 75A are located at the 12 o'clock and 6 o'clock positions on the Z axis, respectively.

[0095] 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 as if overlapping, and the first inner cam protrusion 75A abuts against the first inner cam recess 69A as if overlapping. The overlapping state is symmetrical and overlapped in the front-to-back direction (left-right direction of the paper) with the Z axis as the center in the closed position. 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.

[0096] Therefore, the first mountain portion 781a abuts against the inclined surface of the first valley portion 681a constituting the first outer cam recess 68A, so that the first convex boundary portion 783a of the first outer cam protrusion 74A is located there. Similarly, the second mountain portion 782a abuts against the inclined surface of the second valley portion 682a, so that the second convex boundary portion 784a is located there. In addition, the third mountain portion 791a abuts against the inclined surface of the third valley portion 691a constituting the first inner cam recess 69A, so that the third convex boundary portion 793a of the first inner cam protrusion 75A is located there, and the fourth mountain portion 792a abuts against the inclined surface of the fourth valley portion 692a, so that the fourth convex boundary portion 794a is located there.

[0097] 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; 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 portion 783a, the second convex boundary portion 784a, the third convex boundary portion 793a, and the fourth convex boundary portion 794a abut against the inclined surfaces of the first valley portion 681a, the second valley portion 682a, the third valley portion 691a, and the fourth valley portion 692a, respectively. Therefore, in the closed position, a first initial gap D1 (not shown) is formed between the first concave plane cam portion 67A of the fixed cam washer 61 and the first convex plane cam portion 73A of the first rotating cam washer 62 along the X-axis direction. In this way, the elastic force generated by the plate-shaped spring portion 40 through the first initial gap D1 will cause the first rotating cam washer 62 to be urged toward the fixed cam washer 61, and an elastic force (first pressurization) in the closing direction is applied to the first rotating cam washer 62. In other words, the second housing 3 is applied with the first spring force in the closing direction in the closed position, thereby preventing it from opening.

[0098] When the second housing 3 is first opened from the closed position to the opening direction, the hinge shaft 30 rotates in the opening direction, and a rotation torque in the opening direction is applied to the first rotating cam washer 62. At this time, in the first rotating cam washer 62, the first mountain portion 781a and the third mountain portion 791a on the opening direction side slide as if climbing up the first valley portion 681a and the third valley portion 691a. In addition, the second mountain portion 782a and the fourth mountain portion 792a on the closing direction side are separated from the inclined surface of the second valley portion 682a and the fourth valley portion 692a. Here, among the mountain portions and valley portions that slide together when the hinge shaft 30 rotates in the opening direction, the first mountain portion 781a and the third mountain portion 791a are called the first click mountain portions, and the first valley portion 681a and the third valley portion 691a are called the first click valley portions. The first click hill and the first click valley slide against the elastic force of the plate spring 40 to perform a rotational click action, and the opposing distance between the fixed cam washer 61 and the first rotating cam washer 62 along the X-axis direction is also expanded.

[0099] Next, when the first click hill of the first rotating cam washer 62 crosses the first click valley and stops sliding, the first top portion 76a and the second top portion 77a abut against the first concave plane cam portion 67A and transfer to the arbitrary stop area of ​​the sliding. When the first click hill crosses the first click valley, the first click hill slides in the circumferential direction on the inclined surface of the first click valley and climbs upward, and the disengagement torque applied to the first rotating cam washer 62 will be greater than the rotation torque after transferring to the arbitrary stop area.

[0100] When the first click hill abuts against the first concave cam portion 67A, the distance (gap) between the first concave cam portion 67A of the fixed cam washer 61 and the first convex cam portion 73A of the first rotating cam washer 62 is the cam height h1 of the first click hill. The friction rotation torque required by the arbitrary stop portion 50 depends on the elastic force of the plate spring portion 40, and depends on the elastic force (hereinafter referred to as the appropriate elastic force) corresponding to the spring expansion amount (2h1) twice the cam height (h1) of the first click hill (hereinafter referred to as the appropriate spring expansion amount). Therefore, the appropriate elastic force cannot be obtained by the first rotating cam washer 62 alone, and the appropriate spring expansion amount must be obtained by both the first rotating cam washer 62 and the second rotating cam washer 63.

[0101] 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 is described with reference to Fig. 12(a) and Fig. 12(b). For the convenience of description, Fig. 12(a) and Fig. 12(b) show the state viewed from the second side surface, while Fig. 12(b) shows the second cam protrusion 72B formed on the first side surface in a perspective state and is indicated by a solid line.

[0102] When the second engagement hole 71B is engaged with the square shaft portion 33 of the hinge shaft 3, the Z1 axis of the second rotating cam washer 63 is aligned with the Z axis of the second cam recess 64B. As a result, the second cam protrusion 72B of the second rotating cam washer 63 overlaps the second cam recess 64B and has a rotational offset of an angle θ in the opening direction. In addition, the second cam protrusion 72B is located at a position offset by an angle θ in the opening direction relative to the first cam protrusion 72A of the first rotating cam washer 62.

[0103] In the state where the second housing 3 is closed in the closed position relative to the first housing 2, the second cam recess 64B of the fixed cam washer 61 has the third bottom 68b of the second outer cam recess 68B and the fourth bottom 69b of the second inner cam recess 69B located at the 6 o'clock and 12 o'clock positions on the Z axis, as shown in FIG12(a). In contrast, in the second cam protrusion 72B of the second rotating cam washer 63, the third top 76b of the second outer cam protrusion 74B and the fourth top 77b of the second inner cam protrusion 75B are located at positions offset from the 6 o'clock and 12 o'clock positions on the Z1 axis toward the opening direction by an angle θ.

[0104] 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 as if overlapping, and has an offset of angle θ in the opening direction; the second inner cam protrusion 75B abuts against the second inner cam recess 69B as if overlapping, and has 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. In addition, the fourth sector angle 2β of the fourth bottom 69b of the second inner cam recess 69B is also smaller than the eighth sector angle 2δ of the third top 76b of the second outer cam protrusion 74B. Therefore, just as the first rotating cam washer 62 overlaps with the first cam recess 64A of the fixed cam washer 61, the second rotating cam washer 63 also overlaps with the second cam recess 64B.

[0105] However, the state in which the second outer cam protrusion 74B and the second inner cam protrusion 75B of the second rotating cam washer 63 overlap the second outer cam recess 68B and the second inner cam recess 69B of the second cam recess 64B and are rotated and offset by an angle θ in the opening direction is the closed position. At this time, 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) abut against 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 abutting position of the fifth convex boundary portion 783b and the seventh convex boundary portion 793b of the second click peak abuts against the second click valley is offset by an angle θ in the opening direction compared to the position where the first click peak of the first rotating cam washer 62 abuts against the first click valley of the first cam recess 64A in the closed position. The second click hill climbs up the second click valley due to the offset angle θ, so that a second initial gap D2 (not shown) is formed along the X-axis direction between the second convex plane cam portion 73B of the second rotating cam washer 63 and the second concave plane cam portion 67B of the fixed cam washer 61. The second initial gap D2 is longer than the first initial gap D1.

[0106] Therefore, in fact, the elastic force (second spring force) of the plate spring portion 40 generated by the first initial gap D1 and the second initial gap D2 causes the first rotating cam washer 62 and the second rotating cam washer 63 to apply force toward the fixed cam washer 61, and causes the first rotating cam washer 62 and the second rotating cam washer 63 to apply the second spring force in the closing direction.

[0107] In this embodiment, the first rotating cam washer 62 and the second rotating cam washer 63 are used to reduce the cam height to reduce the disengagement torque, and the offset of the angle θ is set to disperse the disengagement torque. In other words, both are for structurally relieving the rotation torque during opening.

[0108] First, the reason for reducing the height of the cam described above is as follows. As shown in Figures 11(a) and 11(b), the difference (α-β) between the angle α and the angle β is the area on the plane of the first valley 681a (third valley 691a). Assuming that the first rotating cam washer 62 is used to maintain the appropriate elastic force, and the cam depth of the first cam recess 64A of the fixed cam washer 61 is doubled to 2h1, the cam height of the first cam protrusion 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) remains unchanged, the inclination angle of the first click valley will become larger.

[0109] When the appropriate elastic force is applied to the first rotating cam washer 62 along the X-axis direction, if the case where the cam depth of the first cam recess 64A is h1 is compared with the case where the cam depth is doubled to 2h1, the greater the inclination angle of the first click valley, the greater the disengagement torque applied to the hinge shaft 30. Therefore, the structure in which the cam depth of the first cam recess 64A is h1 has a smaller disengagement torque than the structure in which the cam depth is doubled to 2h1.

[0110] Furthermore, if the first initial opening operation area, that is, the angle range (α-δ) of the difference between half angle α of the first sector angle (third sector angle) 2α and half angle δ of the eighth sector angle 2δ, is subtracted from the angle (α-δ-θ) of angle θ, the second initial opening operation area is obtained, that is, in the relationship between the second rotating cam washer 63 and the second cam recess 64B, the second shell 3 is retracted toward the first shell 2, and the opening operation area is prevented by the elastic force of the plate spring portion 40.

[0111] In this way, when the second housing 3 is opened in the closing direction from the closed position, first, the click hill of the click convex portion of the second rotating cam washer 63 will climb over the click valley of the click concave portion of the fixed cam washer 61, and then the click hill of the click convex portion of the first rotating cam washer 62 will climb over the click valley of the click concave portion of the fixed cam washer 61 and move to the arbitrary stop area. There will be a difference between the time point when the click hill of the first rotating cam washer 62 climbs over the click valley of the fixed cam washer 61 and the time point when the click hill of the second rotating cam washer 63 climbs over the click valley of the fixed cam washer 61, so that the generation of the disengagement torque is dispersed.

[0112] Therefore, when the second housing 3 of the notebook computer 1 is in a closed state with the first housing 2 closed at the closed position, the rotational force for opening the second housing 3 in the closed direction is lighter than before, and the opening operation can be performed with one hand.

[0113] Other Implementations

[0114] Contrary to the above-mentioned 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, and a second concave cam portion may be provided on the second rotating cam washer 63, so that they are connected to the hinge shaft 30 and rotate together.

[0115] In addition, the first cam recess 64A and the second cam recess 64B of the fixed cam washer 61 may each form a cam-shaped portion, that is, a pair of outer cam recess and inner cam recess having similar shapes on the outer periphery and the inner periphery; 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 may each form a cam-shaped portion, that is, a pair of outer cam protrusion and inner cam protrusion having similar shapes on the outer periphery and the inner periphery. In contrast, the width of either the pair of outer cam recess and the inner cam recess may be enlarged in the diameter direction to form a single cam-shaped portion.

[0116] (Industrial Applicability) Since the hinge device of the present invention can be operated with one hand, it is particularly suitable for electronic equipment such as image display devices, portable game consoles and notebook computers.

Claims

1. A hinge device, which connects a first shell and a second shell to open and close, wherein the first shell constitutes a main body of an electronic device, and the second shell constitutes a cover of the electronic device, the hinge device comprising: a first bracket mounted on the first housing; a second bracket mounted on the second housing; a hinge shaft fixed to one of the first bracket and the second bracket and connected to the other bracket for rotation; a friction torque generating mechanism having a plate spring and a friction washer disposed on the hinge shaft; as well as a rotation force applying mechanism, which is adjacent to the friction torque generating mechanism and causes the first housing and the second housing to be rotationally forced in a closing direction from a specific closing angle; Wherein, the rotation force applying mechanism comprises: a fixed cam washer which is rotatably provided on the hinge shaft, is joined to one of the first bracket or the second bracket, and has cam recesses in the circumferential direction of both surfaces; and The rotating cam washers are respectively arranged on both sides of the fixed cam washers and are pressed by the elastic force of the plate springs. The rotating cam washers have cam convex parts, and the cam convex parts fall into the respective cam concave parts of the fixed cam washers according to their rotation angles. By staggering the cam recesses or the cam protrusions along the circumferential direction, when each of the cam protrusions falls into each of the cam recesses in sequence, the first shell and the second shell will automatically close from a specific closing angle and maintain a mutually closed state; and when the first shell and the second shell are opened, each of the cam protrusions will disengage from the cam recesses in sequence to alleviate the rotational torque during opening.

2. The hinge device according to claim 1, wherein the cam recess and the cam protrusion provided on the fixed cam washer and each of the rotating cam washers form a cam-shaped portion on the surface of the cam plate body in the shape of a circular plate.

3. A hinge device, which links a first shell and a second shell to open and close, wherein the first shell constitutes a main body of an electronic device, and the second shell constitutes a cover of the electronic device, the hinge device comprising: a first bracket mounted on the first housing; a second bracket mounted on the second housing; a hinge shaft fixed to one of the first bracket and the second bracket and connected to the other bracket for rotation; a friction torque generating mechanism having a plate spring and a friction washer disposed on the hinge shaft; as well as a rotation force applying mechanism, which is adjacent to the friction torque generating mechanism and causes the first housing and the second housing to be rotationally forced in a closing direction from a specific closing angle; Wherein, the rotation force applying mechanism comprises: a fixed cam washer which is rotatably provided on the hinge shaft, is joined to one of the first bracket or the second bracket, and has cam convex portions in the circumferential direction of both surfaces; and The rotating cam washers are respectively arranged on both sides of the fixed cam washers and are pressed by the elastic force of the plate springs. The rotating cam washers have cam recesses, and each of the cam protrusions of the fixed cam washers falls into the cam recesses according to their rotation angles. By staggering the cam recesses or the cam protrusions along the circumferential direction, when each of the cam protrusions falls into each of the cam recesses in sequence, the first shell and the second shell will automatically close from a specific closing angle and maintain a mutually closed state; and when the first shell and the second shell are opened, each of the cam protrusions will disengage from the cam recesses in sequence to alleviate the rotational torque during opening.

4. The hinge device according to claim 3, wherein the cam recess and the cam protrusion provided on the fixed cam washer and each of the rotating cam washers form a cam-shaped portion on the surface of the cam plate body in the shape of a circular plate. 5 . An electronic device having the hinge device according to claim 1 mounted thereon, wherein the first bracket and the second bracket of the hinge device are mounted on the first housing and the second housing of the electronic device.

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