Hinge device and electronic apparatus

Abstract

To provide a hinge device and an electronic apparatus that are able to generate a sufficient torque even with a small diameter and suppress vibration between chassis.SOLUTION: A hinge device 10 includes: a first shaft 26 that is fixed to a display chassis 14; a second shaft 30 that is fixed to a main body chassis 16; connecting plates 32, 34 to which the first shaft 26 and the second shaft 30 are rotatably fitted; a synchronization unit 36 configured to synchronously rotate the first shaft 26 and the second shaft 30 in opposite directions with respect to the connecting plates 32, 34; a first torque application unit 50 configured to apply a frictional force to a peripheral surface of the first shaft 26 by fitting the first shaft 26 thereto; and a second torque application unit 64 configured to apply a frictional force to the second shaft 30 in an axial direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a hinge device that rotatably connects a first housing and a second housing, and to an electronic device in which the first housing and the second housing are rotatably connected by the hinge device. [Background technology]

[0002] Electronic devices such as notebook PCs use a hinge device that connects two housings so that they can rotate relative to one another. This type of electronic device must be able to stably hold the housings at a desired angular position while ensuring smooth rotation between the housings. For this reason, the hinge device must be able to generate an appropriate rotational torque. One example of a mechanism for generating rotational torque is a mechanism that generates sliding resistance by sandwiching a leaf spring between a bracket and a shaft (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2019-190518 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, the diameter needs to be increased in order to generate sufficient rotational torque, which is not desirable for further reducing the thickness of electronic devices.

[0005] Another torque-generating mechanism involves curling one end of a bracket attached to the housing and wrapping it around the hinge shaft to generate sliding resistance. However, to generate sufficient rotational torque, this configuration requires a long curled portion in the axial direction and high-precision straightness of the corresponding shaft, making it difficult to manufacture. Furthermore, this configuration has elasticity in the curled portion, which makes it prone to vibration between the two housings.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to provide a hinge device and an electronic device that can generate sufficient torque despite a small diameter and suppress vibration between housings. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, a hinge device according to an embodiment of the present invention is a hinge device that rotatably connects a first housing and a second housing, and includes a first shaft fixed to the first housing, a second shaft fixed to the second housing, a connecting member into which the first shaft and the second shaft are rotatably fitted, a synchronizing portion that causes the first shaft and the second shaft to rotate synchronously in opposite directions based on the connecting member, a first torque applying portion that applies a frictional force to the circumferential surface of the first shaft by fitting the first shaft, and a second torque applying portion that applies a frictional force to the second shaft in the axial direction.

[0008] Furthermore, an electronic device according to an embodiment of the present invention is an electronic device in which a first housing and a second housing are rotatably connected by a hinge device, and the hinge device has a first shaft fixed to the first housing, a second shaft fixed to the second housing, a connecting member into which the first shaft and the second shaft are rotatably fitted, a synchronizing portion that causes the first shaft and the second shaft to rotate synchronously in opposite directions based on the connecting member, a first torque applying portion that applies a frictional force to the circumferential surface of the first shaft by fitting the first shaft, and a second torque applying portion that applies a frictional force to the second shaft in the axial direction. [Effects of the Invention]

[0009] According to the above aspect of the present invention, rotational torque is applied to the first shaft and the second shaft in a shared manner by the first torque application portion and the second torque application portion, so sufficient torque can be generated. Furthermore, since the first torque application portion covers the circumferential surface, it does not need to be large in diameter, and the second torque application portion does not need to be large in diameter according to the amount of torque it applies, so a small diameter is sufficient, resulting in a small diameter hinge device. The second torque application portion hardly expands or contracts in the circumferential direction, so vibration is less likely to occur between the housings. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic plan view of an electronic device equipped with a hinge device according to an embodiment of the present invention, viewed from above. [Figure 2] Figure 2 is a partially enlarged schematic side view of an electronic device, where (a) shows the state in which the opening / closing angle between the main body housing and the display housing is 0 degrees, (b) shows the state in which it is 90 degrees, (c) shows the state in which it is 170 degrees, (d) shows the state in which it is 270 degrees, and (e) shows the state in which it is 360 degrees. [Figure 3] FIG. 3 is a plan view of the hinge device and its surroundings. [Figure 4] FIG. 4 is an exploded perspective view of the hinge device. [Figure 5] FIG. 5 is a graph showing the torque generated by the hinge device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of a hinge device and an electronic device according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments. The embodiments of the present invention are a hinge device 10 and an electronic device 12 equipped with the hinge device 10.

[0012] FIG. 1 is a perspective view of an electronic device 12 equipped with hinge devices 10, 10, and illustrates a usage state of a notebook PC in which a display housing (first housing) 14 is opened from a main body housing (second housing) 16 by the hinge devices 10, 10. FIG. 2 is a partially enlarged schematic side view of the electronic device 12 shown in FIG. 1 at various angular positions when the display housing 14 is rotated relative to the main body housing 16. The closed state (see FIG. 2(a)) in which the main body housing 16 and the display housing 14 are positioned so that the face of the display 18 (see FIG. 1) and the face of the keyboard 20 (see FIG. 1) face each other is defined as an opening / closing angle of 0 degrees. The open state (see FIG. 2(e)) in which the main body housing 16 and the display housing 14 are rotated relative to each other and the face of the display 18 and the face of the keyboard 20 face each other outward is defined as an opening / closing angle of 360 degrees. Hereinafter, the opening / closing angle of the display housing 14 relative to the main body housing 16 is defined as θ.

[0013] The electronic device 12 according to this embodiment automatically switches between a closed mode, a laptop mode, a stand mode, a tent mode, and a tablet mode based on the opening / closing angle θ of the display housing 14 relative to the main housing 16, and switches between displaying / hiding the display 18, the display orientation of the display 18, and enabling / disabling the keyboard 20 and the touchpad 22 depending on the mode. The electronic device according to the present invention may be a foldable mobile phone, a smartphone, a portable game console, or the like, other than a notebook PC.

[0014] As shown in Figures 1 and 2, electronic device 12 is configured by rotatably connecting end 14b of display housing 14, which has display 18 on its surface 14a, to end 16b of main body housing 16, which has keyboard 20 on its surface 16a, via a pair of left and right hinge devices 10, 10.

[0015] Display housing 14 is thinner and flatter than main body housing 16. Display housing 14 is connected to main body housing 16 by hinge devices 10, 10 provided at end 16b of main body housing 16. Display 18 is a touch panel type liquid crystal display device that can be operated by hand or with a pen as shown by the imaginary lines, and is surrounded by frame 14c.

[0016] The main body housing 16 is configured in the shape of a flat box. The main body housing 16 is connected to the display housing 14 by hinge devices 10, 10 provided at an end 16b of the main body housing 16. Input means such as a keyboard 20 and a touchpad 22 are provided on a surface 16a of the main body housing 16, and various electronic components such as a circuit board, a computing unit, and a memory are provided inside the main body housing 16.

[0017] 2(a) to 2(e), the hinge devices 10, 10 have a two-axis structure that allows the display housing 14 to rotate from a 0-degree position to a 360-degree position. Depending on the design conditions, the rotation range may be less than 360 degrees.

[0018] Next, a specific configuration example of the hinge device 10 will be described. Fig. 3 is a plan view of the hinge device 10 and its surrounding area. Fig. 4 is an exploded perspective view of the hinge device 10. The left and right hinge devices 10 have the same configuration except that they are symmetrical, so the following description will focus on one of the hinge devices 10, and a description of the other hinge device 10 will be omitted. The left and right orientation of the hinge device 10 will be described based on Figs. 3 and 4.

[0019] As shown in FIGS. 3 and 4 , the hinge device 10 is a two-shaft type hinge device configured with a first shaft 26, which is integral with a first bracket 24 fixed to the display housing 14 and protrudes to the right, and a second shaft 30, which is integral with a second bracket 28 fixed to the main housing 16 and protrudes to the right. The first shaft 26 and the second shaft 30 are solid shafts, have the same diameter, and are parallel to each other. The first shaft 26 is slightly longer than the second shaft 30. The hinge device 10 is fixed to the display housing 14 and the main housing 16 by inserting screws into multiple screw holes 24a, 28a formed in the brackets 24, 28, thereby rotatably connecting the two. Depending on the load conditions, serrations or the like may be used to fix the hinge device 10 to the housings.

[0020] A step 26a that acts as a flange is formed at the boundary between the bracket 24 and the first shaft 26. A plurality of annular ridges 26c are formed on the right half of the first shaft 26 to make it easier to receive frictional forces. Two opposing D-cuts 26b are formed on the left half of the first shaft 26. A step 30a that acts as a flange is formed at the boundary between the bracket 28 and the second shaft 30. A male threaded portion 30c is formed at the tip of the second shaft 30, and two opposing D-cuts 30b are formed in the area excluding the male threaded portion 30c.

[0021] The hinge device 10 further has a first connecting plate (connecting member) 32 and a second connecting plate (connecting member) 34 into which the first shaft 26 and the second shaft 30 are rotatably fitted, and a synchronization portion 36 that causes the first shaft 26 and the second shaft 30 to rotate synchronously in opposite directions based on the connecting plates 32, 34.

[0022] Each of the connecting plates 32, 34 is made of two laminated plates 38, providing high strength. If the plate 38 is thick, a single plate will suffice. The plate 38 is an oval-shaped piece with arcuate ends, and a first shaft hole 38a through which the first shaft 26 passes is formed near one end, and a second shaft hole 38b through which the second shaft 30 passes is formed near the other end. The first shaft hole 38a and the second shaft hole 38b have the same diameter. The portion of the plate 38 surrounding the first shaft hole 38a is thicker than the portion surrounding the second shaft hole 38b. Two gear holes 38c are formed side by side in the plate 38 between the first shaft hole 38a and the second shaft hole 38b.

[0023] The synchronizing section 36 is provided between the first connecting plate 32 and the second connecting plate 34, and includes a first shaft gear 40 non-rotatably fitted to the first shaft 26 by the D-cut 28b, a second shaft gear 42 non-rotatably fitted to the second shaft 30 by the D-cut 30b, and two relay gears 44a, 44b provided between the first shaft gear 40 and the second shaft gear 42. Both ends of the relay gears 44a, 44b are journaled in gear holes 38c of the plate 38. The shaft gears 40, 42 have the same number of teeth. The relay gears 44a, 44b also have the same number of teeth. The first shaft gear 40 meshes with the relay gear 44a, the relay gear 44a meshes with the relay gear 44b, and the relay gear 44b meshes with the first shaft gear 40. As a result, the first shaft 26 and the second shaft 30 rotate synchronously in opposite directions.

[0024] Washers 46 are fitted to the first shaft 26 between the first connecting plate 32 and the first shaft gear 40 and at locations where the first shaft 26 abuts against the right side surface of the second connecting plate 34. Fixed washers 48 are fitted to the second shaft 30 between the first connecting plate 32 and the second shaft gear 42 and at locations where the first shaft 26 abuts against the right side surface of the second connecting plate 34. The fixed washer 48 is fitted to the second shaft 30 by the D-cut 30b so as to be non-rotatable. The washers 46 and the fixed washer 48 have the same thickness.

[0025] The first shaft 26 is provided with a first torque applying portion 50. The first torque applying portion 50 applies a frictional force to the circumferential surface of the first shaft 26 by fitting the first shaft 26 thereto.

[0026] The first torque applying portion 50 has a first band 52 and a second band 54 which have different axial lengths. The first band 52 is on the left side and the second band 54 is on the right side, with a narrow gap 56 between the two. In this embodiment, the axial length of the second band 54 is approximately twice as long as that of the first band 52. The axial length of the first band 52 is approximately the same as the diameter of the first shaft 26.

[0027] The first band 52 has a C-shaped cross section made up of a first arc portion 52a and a second arc portion 52b, with a slit 52c formed between the first arc portion 52a and the second arc portion 52b. Similarly, the second band 54 has a C-shaped cross section made up of a first arc portion 54a and a second arc portion 54b, with a slit 54c formed between the first arc portion 54a and the second arc portion 54b. The first arc portions 52a, 54a have a larger arc angle than the second arc portions 52b, 54b. The provision of the slits 52c, 54c creates a difference in torque generated during the opening and closing operations between the housings 14, 16, allowing the opening operation torque and the closing operation torque to be set differently.

[0028] The first torque applying portion 50 is integrated with a cylindrical body 58 that is fitted onto the second shaft 30. The cylindrical body 58 has approximately the same diameter, thickness, and axial position as the first band 52, and is connected to the first band 52 by a connecting portion 60. The connecting portion 60 has a width equal to the diameter of the cylindrical body 58 and extends toward the first band 52, but is slightly narrower in width near the connection with the first band 52. The circumferential surface of the second band 54 and the right side of the connecting portion 60 are connected by a block 62. However, the block 62 is shorter in the axial direction than the second band 52, and in this embodiment, approximately half of the left side of the second band 52 is connected to the block 62. The portion of the block 62 that faces the second shaft 30 is arc-shaped.

[0029] The bands 52, 54 are not limited to a C-shape and may have any shape, such as a cylindrical shape, as long as they are able to apply friction to the fitted first shaft 26. The bands 52, 54 may be formed by curling a portion of the connecting portion 60 and the block 62 into an arc, or may be formed by molding, CNC machining, or the like.

[0030] A second torque application portion 64 is provided on the second shaft 30. The second torque application portion 64 applies a frictional force to the second shaft 30 in the axial direction. The second torque application portion 64 includes fixed washers 66, 68, a plurality of disks (elastic members) 70, and a nut 72, which are fitted or screwed onto the second shaft 30. The step 30a and fixed washer 48 are also part of the second torque application portion 64.

[0031] Fixed washer 66 is provided in a position abutting the right surface of cylindrical body 58, and is non-rotatably fitted to second shaft 30 by D-cut 30b. Fixed washer 66 is about twice as thick as fixed washer 48. Disks 70 are leaf springs formed from dish-shaped metal plates, and in this embodiment, six disks 70 are stacked between fixed washer 66 and fixed washer 68.

[0032] The fixed washer 68 is provided near the end of the second shaft 30 and is non-rotatably fitted to the second shaft 30 by the D-cut 30b. A nut 72 is threaded onto the male thread portion 30c at the right end of the second shaft 26 and is tightened with an appropriate force to the right end of the step 30a via the first connecting plate 32, fixed washer 48, second shaft gear 42, second connecting plate 34, fixed washer 48, cylindrical body 58, fixed washer 66, disc 70, and fixed washer 68. It is advisable to apply a loosening prevention treatment to the nut 72.

[0033] The second torque application unit 64 generates an axial frictional force on the second shaft 30 by tightening the nut 72, which causes the disc 70 to elastically compress. This applies a rotational torque to the second shaft 30 through frictional resistance at the sliding surfaces of the step 30a, connecting plates 32, 34, fixing washers 48, 66, 68, cylindrical body 58, and disc 70. While the provision of many sliding surfaces in this embodiment is advantageous in dispersing the frictional force, the number of sliding surfaces may be increased or decreased depending on the conditions. The number of sliding surfaces can be increased or decreased, for example, by increasing or decreasing the number of discs 70. The hinge device 10 is covered by a cover 74, except for the brackets 24, 28.

[0034] 5 is a graph showing the torque generated by the hinge device 10. In the graph, the dashed-dotted line L11 indicates the torque generated by the first band 52 of the first torque application unit 50, the dashed-dotted line L12 indicates the torque generated by the second band 54 of the first torque application unit 50, the dashed-dotted line L2 indicates the torque generated by the second torque application unit 64, and the solid-line line L0 indicates the total torque generated by the first torque application unit 50 and the second torque application unit 64. The horizontal axis indicates the angle θ, with the area above the horizontal axis indicating the positive torque generated during the opening operation and the area below the horizontal axis indicating the negative torque generated during the closing operation.

[0035] The polarity of the torque generated by the first band 52, the second band 54, the second torque applying unit 64, and the total torque generated by these components differs during the opening and closing operations. Here, we will explain the positive torque generated during the opening operation as an example. The torque generated by the first band 52, indicated by line L11, is zero from approximately 0 to 110 degrees, increases from approximately 110 to 140 degrees, and then maintains a constant torque up to 360 degrees. The first band 52 and the first shaft 26 have different cross-sectional shapes, and different torques can be generated depending on the angle θ due to the position and width of the slit 52c. Note that in the example shown in Figure 5, the absolute values ​​of the torque generated during the opening and closing operations are equal, but as described above, it is also possible to set different torques for the opening operation and the closing operation according to the required specifications.

[0036] The torque generated by the second band 54, indicated by line L12, generates a constant torque from 0 to 360 degrees. The torque generated by the second band 54, which is slightly longer in the axial direction, is slightly larger than the maximum torque of the first band 52, which is shorter.

[0037] The torque generated by the second torque application unit 64, indicated by line L2, increases slightly from approximately 0 to 10 degrees, generates a constant torque from approximately 10 to 350 degrees, and then suddenly decreases from 350 to 360 degrees, realizing an auto-lock function. This prevents residual torque from preventing the tablet from being rotated to 360 degrees when used as a tablet. The maximum torque generated by the second torque application unit 64 is slightly greater than the torque generated by the second band 54. In this embodiment, the maximum torque generated by the second torque application unit 64 is approximately twice the maximum torque generated by the first band 52.

[0038] The total torque shown by line L0 is small near 0 degrees during opening, making it easy to start the operation with one hand, and the torque decreases near 0 degrees during closing, so the residual torque is small and it can be reliably set to 0 degrees.

[0039] The electronic device 12 is typically used when the angle θ is approximately 120 to 130 degrees (see also FIG. 1). This position is indicated by the symbol A. The total torque remains relatively small from 10 degrees to the position indicated by the symbol A, allowing for easy one-handed operation. Furthermore, the total torque increases at the position indicated by the symbol A, making it easier to maintain the angle θ. This makes it difficult for the display 18 to tilt backward, even when touched with a hand or pen during touch panel operation, allowing for stable operation. Furthermore, while the first torque application unit 50 allows for slight circumferential expansion and contraction due to the elasticity of the bands 52 and 54, the second torque application unit 64 exhibits almost no circumferential expansion and contraction, making it difficult for vibration to occur between the display housing 14 and the main housing 16. This facilitates stable touch operation of the display 18, particularly in touch panel-type electronic devices 12.

[0040] The total torque shown by line L0 decreases near 360 degrees during opening, ensuring a 360-degree state, and is small during closing, making it easy to start operation. The total torque is nearly equal at 0 degrees and 360 degrees.

[0041] In the hinge device 10 and electronic device 12 according to this embodiment, the rotational torque is applied by being shared between the first torque application unit 50 and the second torque application unit 64, so that the torque generated by each unit is basically half, and sufficient torque can be generated by adding them together. However, the torque distribution amounts between the first torque application unit 50 and the second torque application unit 64 do not have to be equal, and may differ to some extent.

[0042] The first torque application portion 50 does not need to have a large diameter because the bands 52, 54 cover the circumferential surface. Also, since only half of the torque is applied, it does not need to be long in the axial direction, and the straightness required for the portion of the first shaft 26 that fits in it can be relatively low precision, making it easy to manufacture.

[0043] The second torque application portion 64 only needs to bear half the torque, so it does not need to be large in the radial direction, and a small diameter is sufficient. Since the hinge device 10 requires only a small diameter for the first torque application portion 50, this contributes to making the display housing 14 thinner and the frame body 14c narrower. Furthermore, the small diameter of the second torque application portion 64 contributes to making the main housing 16 thinner. The hinge device 10 is a two-axis type, and the torque application portion 50 provided on the first shaft 26 and the second torque application portion 64 provided on the second shaft 30 are parallel to each other, so the left-right length in FIGS. 3 and 4 can be reduced.

[0044] The present invention is not limited to the above-described embodiment, and can of course be freely modified within the scope of the gist of the present invention. [Explanation of symbols]

[0045] 10 Hinge device 12 Electronic equipment 14 Display case (first case) 16 Main unit (second unit) 24 First Bracket 26 First Shaft 28 Second Bracket 30 Second shaft 30a Step (flange) 32 First connecting plate 34 Second connecting plate 36 Synchronization section 38 Plate 48,66,68 Fixing washer 50 First torque applying section 52 Band 1 54 Second Band 58 Cylinder 60 Connection part 62 blocks 64 Second torque applying section 70 discs 72 Nut

Claims

1. A hinge device that rotatably connects a first housing and a second housing, a first shaft fixed to the first housing; a second shaft fixed to the second housing; a connecting member in which the first shaft and the second shaft are rotatably fitted; a synchronization unit that synchronizes the first shaft and the second shaft with each other in opposite directions relative to the connecting member; a first torque applying portion that applies a frictional force to a circumferential surface of the first shaft by fitting the first shaft thereto; a second torque applying portion that applies a frictional force to the second shaft in an axial direction; have A hinge device characterized by the above.

2. The hinge device according to claim 1, The second torque applying portion is a flange formed on the second shaft; a nut that is threaded onto the threaded portion of the second shaft and fastened between the second shaft and the flange via an elastic member; have A hinge device characterized by the above.

3. The hinge device according to claim 1, The first torque applying portion is integral with a cylindrical body that is fitted onto the second shaft. A hinge device characterized by the above.

4. The hinge device according to claim 1, The first torque applying portion has a first band and a second band having different axial lengths. A hinge device characterized by the above.

5. An electronic device in which a first housing and a second housing are rotatably connected by a hinge device, The hinge device includes: a first shaft fixed to the first housing; a second shaft fixed to the second housing; a connecting member in which the first shaft and the second shaft are rotatably fitted; a synchronization unit that synchronizes the first shaft and the second shaft with each other in opposite directions relative to the connecting member; a first torque applying portion that applies a frictional force to a circumferential surface of the first shaft by fitting the first shaft thereto; a second torque applying portion that applies a frictional force to the second shaft in an axial direction; have An electronic device characterized by:

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