Hinge device

Abstract

To provide a hinge device that maintains a holding force such that small torque is sufficient to open a cover closed at an angle of 0 degree, touch input does not move the cover at angles around 90 degrees, the cover and a casing of a body do not move when the cover is opened at an angle position of 180 degrees.SOLUTION: When a second casing 12 is opened at 107 degrees to a first casing 11, a first protruded part 513 of a first cam member 51 begins to ride on a third protruded part of a second cam member 52 and a second protruded part 514 of the first cam member 51 begins to ride on a fourth protruded part of the second cam member 52, so that a disc spring 61 is compressed to make friction torque greater with a predetermined inclined surface. When the second casing 12 is opened at 134 degrees to the first casing 11, the first protruded part 513 of the first cam member 51 rides on a flat portion of the third protruded part of the second cam member 52 and a second protruded part 514 of the first cam member 51 rides on a flat portion of the protruded part of the second cam member 52. Nevertheless, friction torque is made constant with no change in the compression amount of the disc spring 61.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hinge device for electronic devices, and more particularly to a hinge device used in foldable electronic devices such as personal computers, portable information terminals, electronic notebooks, portable game consoles, and mobile phones. [Background technology]

[0002] Mobile computers such as laptops have a housing, which is a cover equipped with an LCD display and other components, attached to a main body housing equipped with a CPU, magnetic disk, memory, keyboard, and other components, allowing the cover to be opened and closed freely. In such foldable electronic devices, the hinge device attached to the connection between the main body and the cover often incorporates a "free-stop mechanism" that allows the cover to remain open at any angle. Furthermore, when manually opening and closing the cover, the torque required often varies depending on the angle at which the cover is opened. From the perspective of user convenience, it is preferable for the cover to be opened initially with a low torque to prevent the main body housing from lifting up along with the cover, to maintain a holding force that prevents the cover from moving even when touch input is made at an angle of around 90 degrees, and to maintain a holding force that prevents the cover and the main body housing from moving even when opened at an angle of 180 degrees.

[0003] Therefore, as a free-stop mechanism that maintains a predetermined torque at any opening angle, a hinge mechanism has been proposed (Patent Document 1) in which the convex cam 9 and the concave cam 10 engage with each other when the cover is opened at an opening angle of 0 degrees, but do not engage with each other when the cover is opened at an opening angle of 180 degrees. However, with the hinge mechanism described in Patent Document 1, the torque gradually increases when the cover is opened until the opening angle reaches a predetermined torque. Furthermore, Patent Document 2 proposes a hinge mechanism that controls the opening and closing torque according to the opening and closing angle of the cover using a rotating cam 40 whose frictional contact area varies depending on the angular position in the circumferential direction and a non-rotating cam 50 having a convex portion 51. However, the hinge mechanism described in Patent Document 2 generates a large torque when the cover is opened. Furthermore, the hinge mechanism of Patent Document 3 combines a convex cam 8, a concave cam 7, and a friction sliding surface, so that the torque is zero when the cover is opened between 0 and 60 degrees (see the torque curve in Figure 8 of Patent Document 3), gradually increases between 60 and 90 degrees, and remains constant above 90 degrees. However, the hinge mechanism described in Patent Document 3 has a step 3a on the shaft portion 3a of the shaft 3, and includes a "torque release mechanism" that allows the end 4d of the spacer plate 4b to abut against the step 3ac on the shaft portion 3a. Therefore, when the convex portion of the convex cam 8 is engaged with the concave portion of the concave cam 7 and depressed (see Figure 7 of Patent Document 3), the "torque release mechanism" prevents the axial biasing force due to the pressing force of the elastic means 4 from acting on the sliding surfaces of the concave cam 7 and the convex cam 8, and the torque becomes zero. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-332874 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-60059 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-48906 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention was made against the above background and achieves the following objectives: The object of the present invention is to provide a hinge device that can open a cover closed at 0 degrees with a small torque, maintain a holding force so that the cover does not move even when touch input is made to the screen of the cover at an angle of around 90 degrees, and maintain a holding force so that the cover and the main body housing do not move even when the cover is open at an angle of 180 degrees. Another object of the present invention is to provide a hinge device that has a simple structure that does not require a "torque release mechanism" and that is easy to manufacture. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention takes the following measures. That is, the hinge device of the present invention 1 is A housing that is composed of a first housing (11) and a second housing (12) that open and close relative to each other; a first bracket (21) fixed to the first housing (11); a second bracket (22) fixed to the second housing (12); a shaft (3) that rotatably connects the first bracket (21) and the second bracket (22); A contact surface that is connected to either the first bracket (21) or the second bracket (22) and comes into frictional contact with the Arranged 180 degrees symmetrically around the center of rotation a friction disk (4) in which contact surfaces (42, 43) are arranged at positions whose distances from the center of rotation vary depending on the angular position in the circumferential direction; The friction disc (4) is connected to either the first bracket (11) or the second bracket (22). The aforementioned a convex surface portion (226) that is pressed against the contact surfaces (42, 43) and rotates in contact therewith; a biasing mechanism that applies the pressing force; In a hinge device comprising: a first cam member (51) connected to either the first bracket (21) or the second bracket (22) and having a first protrusion (513) and a second protrusion (514); a second cam member (52) that is connected to the other of the first bracket (21) or the second bracket (22), that has a first recess (526) that engages with the first protrusion (513) and a second recess (527) that engages with the second protrusion (514) when the opening angle between the first housing (11) and the second housing (12) is 0 degrees, and that maintains its rotational position; The second cam member (52) has a third protrusion (528) on which the first protrusion (513) rides and a fourth protrusion (529) on which the second protrusion (514) rides when the opening angle between the first housing (11) and the second housing (12) is 180 degrees, thereby preventing a decrease in torque. death, The friction disc (4) The aforementioned The contact surfaces (42, 43) are formed on both side surfaces of the friction disc (4), a convex surface portion (524) that comes into frictional contact with one of the contact surfaces is formed on the second cam member (52), and a convex surface portion (226) that comes into frictional contact with the other contact surface is formed on the second bracket (22). And, The fitting gap between the shaft (3) and the friction disc (4) and the fitting gap between the shaft (3) and the first cam member (51) are reduced. and connected so that it cannot rotate. The friction disc (4) and the first cam member (51) are formed with clearance-reducing portions (46) for preventing backlash.

[0007] The hinge device of the present invention 2 is the hinge device of the present invention 1, wherein the friction disc (4) contacting the convex surface portion (226) The aforementioned The contact surfaces (42, 43) are characterized in that the distance from the center of rotation of the friction disc (4) is small when the opening angle between the first housing (11) and the second housing (12) is 0 degrees and 180 degrees.

[0008] The hinge device of Invention 3 is characterized in that, in Invention 1 or 2, the first convex portion and the second convex portion are formed at different distances from the center of rotation of the first cam member, the first convex portion and the third convex portion are formed at the same distance from the center of rotation of the first cam member, and the second convex portion and the fourth convex portion are formed at the same distance from the center of rotation of the first cam member. [Effects of the Invention]

[0009] The hinge device of the present invention opens the second housing with a small torque when opening it relative to the first housing closed at 0 degrees, and at an angle of around 90 degrees, a holding force is maintained so that the second housing does not move even when touch input is made to the screen of the second housing.Even when open at an angle of 180 degrees, a predetermined holding force can be maintained so that the second housing does not move relative to the first housing. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an exploded perspective view of the hinge device of the present invention, as viewed obliquely from above on the left. [Figure 2] FIG. 2 is an exploded perspective view of the hinge device of the present invention, as viewed obliquely from above right. [Figure 3] FIG. 3 is a front view showing the assembled state of the hinge device of the present invention, and is also an explanatory view showing the contact surfaces when the hinge device of the present invention is opened and closed. [Figure 4] FIG. 4 shows the second cam member of the hinge device of the present invention, where (a) is a perspective view seen from diagonally above the left, and (b) is a perspective view seen from diagonally above the right. [Figure 5] FIG. 5 is a part view showing the second cam member of FIG. 4 in third angle projection. [Figure 6] FIG. 6 shows the first cam member of the hinge device of the present invention, where (a) is a perspective view seen from diagonally above the left, and (b) is a perspective view seen from diagonally above the right. [Figure 7] FIG. 7 is a part view showing the first cam member of FIG. 6 in third angle projection. [Figure 8]FIG. 8 shows a friction disc of a hinge device of the present invention, where (a) is a perspective view seen from diagonally above the left, and (b) is a perspective view seen from diagonally above the right. [Figure 9] FIG. 9 is a part drawing showing the friction disc of FIG. 8 in third angle projection. [Figure 10] FIG. 10 is an explanatory view showing a state in which the shaft of the hinge device of the present invention is fitted to the first cam member. [Figure 11] Figure 11(a) is an enlarged cross-sectional view of AA in Figure 10, showing the clearance-reducing portion for reducing the fitting gap between the shaft and the first cam member, and Figure 11(b) shows the state in which the shaft has been removed from Figure 11(a). [Figure 12] FIG. 12 is an enlarged perspective view of the friction disc, the second cam member, and the first cam member as viewed obliquely from above left. [Figure 13] FIG. 13 is an explanatory diagram showing the change in the contact surface between the friction disc and the convex portion of the second bracket depending on the opening angle when the second housing is opened relative to the first housing. [Figure 14] FIG. 14 is an explanatory diagram showing the change in the contact surface after FIG. [Figure 15] FIG. 15 is an explanatory diagram showing the engagement state of the cam surfaces of the first cam member and the second cam member that changes depending on the opening angle when the second housing is opened relative to the first housing. [Figure 16] FIG. 16 is an explanatory diagram showing the engagement state of the cam surfaces subsequent to that of FIG. [Figure 17] FIG. 17 is a torque diagram showing the change in torque when the hinge device of the present invention is opened and closed. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 shows a hinge device 1 of the present invention, and is an exploded perspective view thereof as viewed from diagonally above left. FIG. 2 is an exploded perspective view thereof as viewed from diagonally above right. FIG. 3 is a front view showing the assembled hinge device of the present invention and is also an explanatory diagram showing the contact surfaces when the hinge device of the present invention is opened and closed. As shown in FIGS. 1 and 2, the hinge device 1 of the present invention is composed of a first housing 11, a second housing 12, a first bracket 21, a second bracket 22, a shaft 3, a friction disk 4, a first cam member 51, a second cam member 52, a disc spring 6, a caulking plate 7, and the like. Specifically, the first housing 11 is the housing of a main body of a notebook computer or the like, which is equipped with a CPU, a magnetic disk, a memory, a keyboard, and the like, and the second housing 12, which is a cover equipped with a liquid crystal display and the like, is attached to the first housing 11 so as to be freely opened and closed. FIGS. 1 and 2 show the second housing 12 completely closed relative to the first housing 11.

[0012] In order to pivotally support the second housing 12 relative to the first housing 11 so that it can be opened and closed freely, a first bracket 21 is fixed to the first housing 11, and a second bracket 22 is fixed to the second housing 12. The first bracket 21 is fixed to the first housing 11 with two screws 111, and the second bracket 22 is fixed to the second housing 12 with two screws 121. A cylindrical shaft 3 is formed integrally with the first bracket 21, and a disk-shaped flange 211 with a diameter larger than that of the shaft 3 is formed at the joint between the shaft 3 and the first bracket 21. The shaft 3 is formed with a non-circular two-flat portion 31 over almost the entire length in the axial direction. A circular bearing hole 222 is formed in the flange 221 of the second bracket 22, and the bearing hole 222 is formed with an inner diameter dimension that fits tightly against the cylindrical outer peripheral surface of the shaft 3. When the shaft 3 is inserted into the bearing hole 222, the second bracket 22 is rotatably supported on the shaft 3, and as a result, the second housing 12 is supported on the first housing 11 so as to be able to be opened and closed freely.

[0013] 1 to 3 , the shaft 3 is inserted until the right side surface 212 of the flange 211 of the shaft 3 abuts against the left side surface 224 of the flange 221 of the second bracket 22. Next, the friction disc 4, the second cam member 52, the first cam member 51, the four disc springs 6, and the caulking plate 7 are inserted onto the shaft 3 in this order. A circular bearing hole 521 is formed in the second cam member 52, and the inner diameter of the bearing hole 521 is the same as the inner diameter of the bearing hole 222 of the flange 221. A rectangular engagement hole 223 is formed in the flange 221 of the second bracket 22, and the engagement protrusion 522 formed on the second cam member 52 is inserted into and locked in the engagement hole 223, so that the second cam member 52 is rotatably supported relative to the shaft 3. The friction disk 4, the first cam member 51, the four disc springs 6, and the crimping plate 7 have formed therein width-across-flat holes 41, 511, 61, and 71 shaped to fit tightly with the width-across-flat portion 31 of the shaft 3. As shown in Fig. 3, when the crimping plate 7 is crimped and fixed to the shaft 3 with the four disc springs 6 compressed by a predetermined amount, the biasing force of the disc springs 6 acts on the relatively rotating contact surfaces 1 and 4 in Fig. 3, completing the assembly of the hinge device 1 of the present invention. As a result, when the second housing 12 is opened or closed relative to the first housing 11, the flange 221 of the second bracket 22 and the second cam member 52 rotate relative to the shaft 3, and the friction disk 4, the first cam member 51, the four disc springs 6, and the crimping plate 7 remain stationary together with the shaft 3. A female screw may be formed at the axis of the crimping plate 7, and the crimping plate 7 may be screwed onto a male screw formed at the tip of the shaft 3 to be fixed.

[0014] FIG. 4 shows the second cam member 52, with (a) being a perspective view seen from diagonally above left, and (b) being a perspective view seen from diagonally above right. FIG. 5 is a component drawing showing the second cam member 52 of FIG. 4 in third-angle perspective. As shown in FIGS. 4 and 5, convex surface portions 524, 524 are formed radially at positions 180 degrees symmetrical about the center of rotation of the second cam member 52 on the left side surface 523 of the second cam member 52 (the surface facing the friction disc 4) as viewed in FIG. 4. A first recess 526 and a second recess 527 are formed at positions 180 degrees symmetrical about the center of rotation of the second cam member 52 on the right side surface 525 of the second cam member 52 (the surface facing the first cam member 51) as viewed in FIG. 4. First recess 526 and second recess 527 are formed at different distances from the center of rotation of second cam member 52, with first recess 526 being formed at a greater distance from the center of rotation of second cam member 52 than second recess 527. Also, third convex portion 528 and fourth convex portion 529 are formed on right side surface 525 of second cam member 52 (surface facing first cam member 51) at positions 180 degrees symmetrical to first recess 526 and second recess 527. Third convex portion 528 and fourth convex portion 529 are formed at different distances from the center of rotation of second cam member 52, with third convex portion 528 being formed at a greater distance from the center of rotation of second cam member 52 than fourth convex portion 529.

[0015] FIG. 6 shows the first cam member 51, with (a) being a perspective view from diagonally above left and (b) being a perspective view from diagonally above right. FIG. 7 is a component drawing showing the first cam member of FIG. 6 in third-angle perspective. As shown in FIGS. 6 and 7, a first convex portion 513 and a second convex portion 514 are formed on the left side surface 512 of the first cam member 51 (the surface facing the second cam member 52) at positions 180 degrees symmetrical about the center of the first cam member 51. The first convex portion 513 and the second convex portion 514 are formed at different distances from the center of rotation of the first cam member 51, with the first convex portion 513 being formed at a greater distance from the center of rotation of the first cam member 51 than the second convex portion 514. The distance of the first convex portion 513 from the center of rotation of the first cam member 51 is formed to be the same as that of the first recessed portion 526 and the third convex portion 528 of the second cam member 52. Similarly, the distance from the center of rotation of first cam member 51 to second convex portion 514 is formed to be the same as that of second concave portion 527 and fourth convex portion 529 of second cam member 52. Right side surface 515 of first cam member 51 (surface facing disc spring 61) is formed flat.

[0016] FIG. 8 shows the friction disc 4, where (a) is a perspective view seen from diagonally above left, and (b) is a perspective view seen from diagonally above right. FIG. 9 is a component drawing showing the friction disc 4 of FIG. 8 using third-angle projection. As shown in FIGS. 8 and 9, small-diameter sector-shaped contact surfaces 42, 42 that are closer to the center of rotation of the friction disc 4 and large-diameter sector-shaped contact surfaces 43, 43 that are farther from the center of rotation of the friction disc 4 are formed on the left side 44 and the right side 45 of the friction disc 4, at positions 180 degrees symmetrical about the center of rotation of the friction disc 4. As a result, when the second housing 12 is opened or closed relative to the first housing 11, the small-diameter sector-shaped contact surfaces 42, 42 and the large-diameter sector-shaped contact surfaces 43, 43 on the right side 45 come into contact with the convex surfaces 524, 524 of the second cam member 52, generating a predetermined torque. 2, convex surface portions 226, 226 are formed radially on a right side surface 225 of a flange 221 of the second bracket 22 at positions 180 degrees symmetrical with respect to the center of the bearing hole 222 of the flange 221. As a result, when the second housing 12 is opened or closed relative to the first housing 11, the small-diameter sector-shaped contact surfaces 42, 42 and the large-diameter sector-shaped contact surfaces 43, 43 on the left side surface 44 of the friction disc 4 come into contact with the convex surface portions 226, 226 of the second bracket 22, generating a predetermined torque.

[0017] FIG. 10 is an explanatory diagram showing the fitted state of the shaft 3 and first cam member 51 of the hinge device 1 of the present invention, and FIG. 11 is an enlarged cross-sectional view taken along line AA in FIG. 10 , showing clearance-reducing portions for reducing the fitting gap between the shaft 3 and the first cam member 51. As shown in FIGS. 10 and 11 , clearance-reducing portions 516, 516, 516, 516, which have a narrow width across flats, are formed at the four corners of the two-flat hole 511 of the first cam member 51, thereby eliminating the fitting gap with the two-flat portion 31 of the shaft 3. By eliminating the fitting gap only at the four corners, there is no looseness between the shaft 3 and the first cam member 51, improving the quality of the hinge device. In addition, because the press-fitting force between the shaft 3 and the first cam member 51 is an appropriate value, torque fluctuations can be reduced when opening and closing the second housing 12 relative to the first housing 11. For the same purpose, as shown in FIG. 9, the two-surface wide hole 41 of the friction disc 4 is also formed with backlash-reducing portions 46, 46, 46, 46 of the same shape.

[0018] Next, we will explain the change in torque when the second housing 12 is opened or closed relative to the first housing 11. When the second housing 12 is opened or closed relative to the first housing 11, friction torque occurs due to relative rotation at four locations, contact surfaces 1 to 4, as shown in FIG. 3. Contact surface 4, between the right side surface 212 of the flange 211 of the shaft 3 and the left side surface 224 of the flange 221 of the second bracket 22, has almost no fluctuation in friction torque because both the right side surface 212 and the left side surface 224 are flat surfaces, so it does not affect the change in torque during opening or closing. The three locations where friction torque is large and where the fluctuation is large are contact surface 1 (the contact surface between the first cam member 51 and the second cam member 52), contact surface 2 (the contact surface between the right side surface 45 of the friction disc 4 and the convex surface 524 of the second cam member 52), and contact surface 3 (the contact surface between the left side surface 44 of the friction disc 4 and the convex surface 226 of the second bracket 22). The torque of contact surface 2 and contact surface 3 changes in a direction that suppresses the torque fluctuation of contact surface 1, which has a large torque fluctuation. FIG. 17(b) is a torque diagram of contact surface 1 (the contact surface between the first cam member 51 and the second cam member 52). FIG. 17(c) is a torque diagram that sums the torque of contact surface 2 (the contact surface between the right side surface 45 of the friction disc 4 and the convex surface portion 524 of the second cam member 52) and contact surface 3 (the contact surface between the left side surface 44 of the friction disc 4 and the convex surface portion 226 of the second bracket 22). FIG. 17(a) is a torque diagram that sums the torques of FIG. 17(b) and FIG. 17(c).

[0019] FIG. 13 is an explanatory diagram showing the change in the contact surface between the friction disc 4 and the convex surface portion 226 of the second bracket 22, which changes depending on the opening angle when the second housing 12 is opened relative to the first housing 11. FIG. 14 is an explanatory diagram showing the change in the contact surface after FIG. 13. The change in the contact surface between the friction disc 4 and the convex surface portion 524 of the second cam member 52 is also the same as in FIGS. 13 and 14. As shown in FIG. 13(a), when the second housing 12 is closed relative to the first housing 11, the convex surface portion (shown by the two-dot chain line) 226 of the second bracket 22 is in contact with the small-diameter sector-shaped contact surfaces 42, 42 of the friction disc 4, and therefore a small friction torque is generated as shown in FIG. 17(c). When the second housing 12 begins to open relative to the first housing 11, the first cam member 51 rotates relative to the second cam member 52, the first convex portion 513 of the first cam member 51 slips out of the first concave portion 526 of the second cam member 52, and the second convex portion 514 of the first cam member 51 slips out of the second concave portion 527 of the second cam member 52, gradually compressing the disc spring 61 and gradually pressing the friction disc 4 more firmly against the second bracket 22. As a result, as shown in Figure 13(a), when the convex portion 226 of the second bracket 22 comes into contact with the small-diameter sector-shaped contact surfaces 42, 42 of the friction disc 4 and rotates, the friction torque gradually increases at a gentle slope as shown in Figure 17(c).

[0020] As shown in FIG. 13(b), when the second housing 12 is opened 12 degrees relative to the first housing 11, the convex surface 226 of the second bracket 22 begins to contact the large-diameter sector-shaped contact surfaces 43, 43 of the friction disk 4, and the friction torque increases at a steeper slope, as shown in FIG. 17(c). As shown in FIG. 13(c), when the second housing 12 is opened 50 degrees relative to the first housing 11, the convex surface 226 of the second bracket 22 begins to contact only the large-diameter sector-shaped contact surfaces 43, 43 of the friction disk 4, and the friction torque becomes constant, as shown in FIG. 17(c). As shown in FIG. 14(a), when the second housing 12 is opened 130 degrees relative to the first housing 11, the convex surface 226 of the second bracket 22 begins to contact the small-diameter sector-shaped contact surfaces 42, 42 of the friction disk 4, and the friction torque begins to decrease, as shown in FIG. 17(c). As shown in Figure 14(b), when the second housing 12 opens 168 degrees relative to the first housing 11, the convex surface portion 226 of the second bracket 22 begins to contact only the small diameter sector-shaped contact surfaces 42, 42 of the friction disk 4, and the friction torque further decreases as shown in Figure 17(c). As shown in Figure 14(c), when the second housing 12 opens 180 degrees relative to the first housing 11 and stops, the convex surface portion 226 of the second bracket 22 comes into contact only with the small diameter sector-shaped contact surfaces 42, 42 of the friction disk 4, and the friction torque decreases but does not become zero as shown in Figure 17(c). The reason for this is that, as will be described later, when second housing 12 opens 180 degrees relative to first housing 11, first convex portion 513 of first cam member 51 rides up on the flat portion of third convex portion 528 of second cam member 52, and second convex portion 514 of first cam member 51 rides up on the flat portion of convex portion 529 of second cam member 52, causing disc spring 61 to be strongly compressed.

[0021] 15 is an explanatory diagram showing the engagement state of the cam surfaces of first cam member 51 and second cam member 52, which changes depending on the opening angle when second housing 12 is opened relative to first housing 11. FIG. 16 is an explanatory diagram showing the engagement state of the cam surfaces after FIG. 15. As shown in FIG. 15(a), when second housing 12 is closed relative to first housing 11, first convex portion (shown by a two-dot chain line) 513 of first cam member 51 is located halfway along the cam slope of first recess 526 of second cam member 52, and second convex portion (shown by a two-dot chain line) 514 of first cam member 51 is located halfway along the cam slope of second recess 527 of second cam member 52, so that a small friction torque is generated as shown in FIG. 17(b). The reason for this is that the depth of first recess 526 is slightly greater than the height of first protrusion 513, and the depth of second recess 527 is slightly greater than the height of second protrusion 514. When second housing 12 begins to open with respect to first housing 11, first cam member 51 rotates relative to second cam member 52, first protrusion 513 of first cam member 51 begins to slip out of first recess 526 of second cam member 52, and second protrusion 514 of first cam member 51 begins to slip out of second recess 527 of second cam member 52. As a result, disc spring 61 is gradually compressed, and first cam member 51 is gradually pressed more strongly against second cam member 52, so that the friction torque temporarily increases and then decreases slightly, as shown in FIG. 17(b).

[0022] As shown in Figure 15(b), when the second housing 12 opens 22 degrees relative to the first housing 11, the flat surface of the first convex portion 513 of the first cam member 51 rides up on the right side surface 525 of the second cam member 52, and the flat surface of the second convex portion 514 of the first cam member 51 rides up on the right side surface 525 of the second cam member 52, and since the amount of compression of the disc spring 61 does not change, the friction torque becomes constant as shown in Figure 17(b). As shown in Figure 15(c), when the second housing 12 opens 107 degrees relative to the first housing 11, the first convex portion 513 of the first cam member 51 begins to ride up onto the third convex portion 528 of the second cam member 52, and the second convex portion 514 of the first cam member 51 begins to ride up onto the fourth convex portion 529 of the second cam member 52, so that the disc spring 61 is gradually compressed and the friction torque gradually increases at a predetermined gradient as shown in Figure 17(b). As shown in Figure 16(a), when the second housing 12 opens 134 degrees relative to the first housing 11, the first convex portion 513 of the first cam member 51 rides up on the flat portion of the third convex portion 528 of the second cam member 52, and the second convex portion 514 of the first cam member 51 rides up on the flat portion of the convex portion 529 of the second cam member 52, and since the amount of compression of the disc spring 61 does not change, the friction torque becomes constant as shown in Figure 17(b). As shown in Figure 16(b), when second housing 12 opens 180 degrees relative to first housing 11 and stops, first convex portion 513 of first cam member 51 completely rides on the flat portion of third convex portion 528 of second cam member 52, and second convex portion 514 of first cam member 51 completely rides on the flat portion of convex portion 529 of second cam member 52, and the amount of compression of disc spring 61 does not change, so the friction torque is maintained at a constant state as shown in Figure 17(b).

[0023] 17(a) is a torque diagram that sums the torques of contact surface 1, contact surface 2, and contact surface 3 in FIG. 3. As shown in the torque diagram in FIG. 17(a), the hinge device 1 of the present invention requires a small torque to open the second housing 12 relative to the first housing 11 that is closed at 0 degrees, but because the torque is large at an angle of around 90 degrees, a holding force is maintained so that the second housing 12 does not move even when a touch input is made to the screen of the second housing 12. Even when the hinge device 1 is open at an angle of 180 degrees, a large torque is required, so a predetermined holding force can be maintained so that the second housing 12 does not move relative to the first housing 11. Furthermore, the hinge device 1 of the present invention has a simple structure that does not require a "torque release mechanism," making it easy to manufacture.

[0024] Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. For example, in the above-described embodiment, the small diameter sector-shaped contact surface and the large diameter sector-shaped contact surface are formed on both sides of the friction disk, but it is also possible to form only one side. [Explanation of symbols]

[0025] 1... Hinge device 11...First enclosure 111...bis 12...Second housing 121...bis 21...First bracket 211...Flange 212…Right side 22...Second bracket 221...Flange 222...bearing hole 223...Engagement hole 224...Left side 225…Right side 226...Convex part 3...Shaft 31…Width across flats part 4...Friction disc 41…Width across flats hole 42…Small diameter fan-shaped contact surface 43...Large diameter fan-shaped contact surface 44...Left side 45…Right side 46...Reducing backlash 51...first cam member 511…Width across flats hole 512...Left side 513...First protrusion 514...Second protrusion 515...Right side 516…Reduced backlash 52...second cam member 521...bearing hole 522…Engagement protrusion 523...Left side 524...Convex part 525…Right side 526...first recess 527...Second recess 528...Third convex part 529...Fourth convex part 6...Disc spring 61…Width across flats hole 7... Crimp plate 71…Width across flats hole

Claims

1. A housing that is composed of a first housing (11) and a second housing (12) that open and close relative to each other; a first bracket (21) fixed to the first housing (11); a second bracket (22) fixed to the second housing (12); a shaft (3) that rotatably connects the first bracket (21) and the second bracket (22); a friction disk (4) connected to either the first bracket (21) or the second bracket (22), with contact surfaces that come into frictional contact arranged at positions 180 degrees symmetrical with respect to the center of rotation, and with contact surfaces (42, 43) arranged at positions whose distances from the center of rotation vary depending on the angular position in the circumferential direction; a convex surface portion (226) connected to either the first bracket (11) or the second bracket (22) and pressed against the contact surface (42, 43) of the friction disc (4) to rotate in contact therewith; a biasing mechanism that applies the pressing force; In a hinge device comprising: a first cam member (51) connected to either the first bracket (21) or the second bracket (22) and having a first convex portion (513) and a second convex portion (514); a second cam member (52) that is connected to the other of the first bracket (21) or the second bracket (22), and has a first recess (526) that engages with the first protrusion (513) and a second recess (527) that engages with the second protrusion (514) when the opening angle between the first housing (11) and the second housing (12) is 0 degrees, and whose rotational position is maintained; The second cam member (52) has a third convex portion (528) on which the first convex portion (513) rides and a fourth convex portion (529) on which the second convex portion (514) rides when the opening angle between the first housing (11) and the second housing (12) is 180 degrees, thereby preventing a decrease in torque; the contact surfaces (42, 43) of the friction disc (4) are formed on both side surfaces of the friction disc (4), a convex surface portion (524) that comes into frictional contact with one of the contact surfaces is formed on the second cam member (52), and a convex surface portion (226) that comes into frictional contact with the other contact surface is formed on the second bracket (22); The friction disc (4) and the first cam member (51) are provided with clearance-reducing portions (46) for reducing the fitting gap between the shaft (3) and the friction disc (4) and the fitting gap between the shaft (3) and the first cam member (51) to couple them non-rotatably. A hinge device characterized by the above.

2. The hinge device according to claim 1, The contact surfaces (42, 43) of the friction disk (4) that come into contact with the convex surface portion (226) are formed so that the distance from the center of rotation of the friction disk (4) is small when the opening angle between the first housing (11) and the second housing (12) is 0 degrees and 180 degrees. A hinge device characterized by the above.

3. The hinge device according to claim 1 or 2, The first and second convex portions are formed at different distances from the center of rotation of the first cam member, the first and third convex portions are formed at the same distance from the center of rotation of the first cam member, and the second and fourth convex portions are formed at the same distance from the center of rotation of the first cam member. A hinge device characterized by the above.

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