Biasing force generation device and operation assisting device

Abstract

To provide a biasing force generation device capable of switching between a state that a biasing force is generated by an elastic body and a state that generation of the biasing force is prevented.SOLUTION: A biasing force generation device includes: a base part; a support member supported so as to be rotatable relative to the base part; an elastic body which includes a first end and a second end, is supported at the first end by the base part and at the second end by the support member, and is deformed by the support member rotating relative to the base part to generate a biasing force; and a switch part which may switch between a biasing force generating state in which the biasing force by the elastic body may be generated and a no biasing force generating state in which generation of the biasing force by the elastic body is prevented.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a biasing force generating device and a motion assisting device. [Background technology]

[0002] Patent Document 1 discloses a motion support device having a joint mechanism rotatably connected to each of an upper link and a lower link. The joint mechanism has a spiral spring and is configured to apply a biasing force to the upper link and the lower link when the rotation angle of the upper link and the lower link exceeds a predetermined angle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-074320 Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable for the motion assist device to be in a state where it does not generate an assist force (biasing force) when the assist force is not needed. However, the motion assist device disclosed in Patent Document 1 cannot be in a state where it does not generate a biasing force.

[0005] An object of the present disclosure is to provide, for example, a biasing force generating device and an action assisting device that can be switched between a state in which a biasing force is generated by an elastic body and a state in which a biasing force is not generated. [Means for solving the problem]

[0006] In order to achieve the above object, a force generating device according to one aspect of the present disclosure includes a base portion, a support member rotatably supported on the base portion, an elastic body including a first end and a second end, the first end being supported by the base portion and the second end being supported by the support member, the elastic body deforming and generating a force when the support member rotates relative to the base portion, and a switching portion switchable between a force generating state in which a force is generated by the elastic body and a force non-generating state in which a force is not generated by the elastic body.

[0007] The base portion is provided with a rotating shaft having the first end held thereon, and the switching portion may be capable of switching between placing the rotating shaft in a non-rotatable state relative to the base portion, causing the support member to rotate relative to the rotating shaft to deform the elastic body and generate a biasing force, thereby placing the elastic body in the biasing force generating state, or placing the rotating shaft in a rotatable state relative to the base portion, causing the support member to rotate together with the rotating shaft to not generate a biasing force by the elastic body, thereby placing the elastic body in the non-biasing force generating state.

[0008] The switching unit may have a switch mechanism having an operating unit, and by operating the operating unit, the rotating shaft may be switched to a non-rotatable state relative to the base unit and the elastic body may be switched to the force-generating state, or the rotating shaft may be switched to a rotatable state relative to the base unit and the elastic body may be switched to the force-non-generating state.

[0009] The switching unit may further include a switching lever and a disk portion having a recess, and the switching gear may be provided on the rotating shaft, and by operating the operating unit, the switching lever may fit into the recess of the disk portion, rendering the disk portion non-rotatable, rendering the rotating shaft non-rotatable relative to the base portion, and rendering the elastic body in the force-generating state; alternatively, the switching lever may be configured to move away from the disk portion, rendering the disk portion rotatable, rendering the rotating shaft rotatable relative to the base portion, and rendering the elastic body in the force-non-generating state.

[0010] The elastic body has a first elastic body and a second elastic body, the rotating shaft has a first rotating shaft and a second rotating shaft, the biasing force generating device further includes a transmission unit that transmits the rotation of the first rotating shaft to the second elastic body and transmits the biasing force of the second elastic body to the first rotating shaft, the second elastic body includes the first end and the second end, the first end is held by the second rotating shaft and the second end is supported by the support member, and the support member rotates relative to the base portion to deform and generate a biasing force, the first elastic body includes a third end and a fourth end, the third end is held by the first rotating shaft and the fourth end is supported by the base portion, and the first rotating shaft rotates relative to the base portion to deform and generate a biasing force, and the switching unit is configured to be able to switch between generating and not generating a biasing force by the second elastic body.

[0011] The rotating shaft may have a first rotating shaft and a second rotating shaft, the elastic body having the first end held by the second rotating shaft and the second end supported by the support member, and the elastic body deforms to generate a biasing force as the support member rotates relative to the base portion, the biasing force generating device may further include a transmission portion that transmits the rotation of the first rotating shaft to the elastic body and transmits the biasing force of the elastic body to the first rotating shaft, and the switching portion may be configured to be capable of switching between generating and not generating a biasing force by the elastic body.

[0012] The elastic body may be a spiral spring.

[0013] In order to achieve the above object, a motion-assist device according to one aspect of the present disclosure includes any one of the biasing force generating devices described above. In this case, the motion-assist device may be configured to generate a biasing force by the elastic body when a motion angle of a user wearing the motion-assist device exceeds a predetermined value. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a biasing force generating device and an action assisting device that are switchable between a state in which a biasing force is generated by an elastic body and a state in which a biasing force is not generated. [Brief description of the drawings]

[0015] [Figure 1] 1A and 1B are a side view and a partial front view of a motion assist device according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the drive unit of FIG. [Diagram 3] 3 is an explanatory diagram of a recess in the mainspring case in FIG. 2. FIG. [Figure 4] 3 is a perspective view showing a state in which the spiral spring in FIG. 2 is fixed to a rotating shaft. [Diagram 5] 3 is a side view showing a state in which the spiral spring in FIG. 2 is fixed to a rotating shaft. [Figure 6] FIG. 3 is a perspective view of the switching portion of FIG. 2. [Figure 7] 1A is a schematic side view of the switching portion when the switching gear is in a non-rotatable state, and FIG. 1B is a schematic side view of the switching portion when the switching gear is in a rotatable state. [Figure 8] 13(a) and 13(b) are a side view and a front view of a drive unit of a motion assist device according to a second embodiment. [Figure 9] 13(a) and 13(b) are a side view and a front view of a drive unit of a motion assist device according to a modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a biasing force generating device and a motion assist device according to a first embodiment of the present disclosure will be described. The motion assist device assists a user in a motion to raise his / her upper body (motion to stretch the waist). Fig. 1 is (a) a side view and (b) a partial front view of the motion assist device 1.

[0017] The action-assist device 1 includes an upper part 10 worn by a user, a pair of drive units 20, and a pair of lower limb units 30. In Fig. 1, only one of the pair of drive units 20 and lower limb units 30 is shown. In the following description, the chest support unit 12 side relative to the back support unit 11 is the front side, the back support unit 11 side relative to the chest support unit 12 is the rear side, the upper part 10 side relative to the drive units 20 is the upper side, and the lower limb units 30 side relative to the drive units 20 is the lower side. In Fig. 1, the postures of the upper part 10 and the lower limb units 30 relative to the drive units 20 are the postures when a user wearing the action-assist device 1 is standing upright.

[0018] The upper part 10 has a back support portion 11, a chest support portion 12, an upper frame 13A, a pair of upper frames 13B (only one of which is shown in FIG. 1), and a waist fixing member 14.

[0019] The back support part 11 is a flat plate that contacts the back of the user when worn. The surface of the back support part 11 that contacts the back of the user, i.e., the surface on the front side of the action-assist device 1, is made of a soft material having elasticity. Note that the shape of the back support part 11 is not limited to the form shown in the drawings.

[0020] The chest piece 12 is a member that is worn on the chest of the user. The chest piece 12 has a pair of belt-shaped members made of a soft elastic material so that it can deform in response to the movements of the user. For example, buckles 12A are provided on both ends of the front side of the chest piece 12. The pair of belt-shaped members are connected to each other by the buckles 12A, thereby holding the chest piece 12 in a cylindrical shape. The inner circumference of the chest piece 12 is adjustable, so that the chest piece 12 can be brought into contact with the chest of the user.

[0021] The upper frames 13A and 13B are members that connect the pair of drive units 20, the backrest unit 11, and the pair of chest rest units 12 to one another. The upper frames 13A and 13B are formed by bending a bar material such as a hollow round bar. The upper frames 13A and 13B are rigid bodies, and fix the relative positions of the pair of drive units 20, the backrest unit 11, and the chest rest unit 12.

[0022] The upper frame 13A is provided on the rear side of the backrest 11 and fixes the backrest 11 and the pair of upper frames 13B. The upper frame 13A is curved in an upwardly convex shape. Each upper frame 13B is a member that extends above and below the backrest 11, and its lower end is connected to the upper end of the drive unit 20. A belt-shaped member of the chest rest 12 is connected to the upper end of each of the pair of upper frames 13B.

[0023] The waist fixing member 14 is a single belt-like member and is connected to a pair of drive units 20. Buckles 14A, for example, are provided on both ends of the front side of the waist fixing member 14, and the waist fixing member 14 is held in a cylindrical shape by the buckles 14A. The inner periphery of the waist fixing member 14 is adjustable, so that the waist fixing member 14 can be appropriately abutted against the waist of the user. The waist fixing member 14 is a soft member and can deform in accordance with the movement of the user, allowing the user to move easily.

[0024] The pair of lower leg sections 30 are shaped to generally conform to the thighs of the user as a whole. Each lower leg section 30 has a lower leg plate 31, an axis section 32, a lower leg arm 33, and a thigh pad 34. The upper end of the lower leg plate 31 is rotatably attached to a rotating shaft 22 (see FIG. 2) provided in the driving section 20. The axis section 32 is provided at the lower end of the lower leg plate 31. The lower leg arm 33 is rotatably connected to the axis section 32. The lower leg arm 33 can be rotated by the axis section 32 so as to move closer to and away from the thighs of the user. For example, the lower leg arm 33 and the lower leg plate 31 to which it is connected correspond to a lower frame.

[0025] Each thigh pad 34 is a curved member that covers the front side of the user's thigh. Each thigh pad 34 is provided at the tip of each lower leg arm 33. When the user brings each thigh pad 34 into contact with the front side of the user's thigh, the movement of the thigh is transmitted to each drive unit 20.

[0026] Next, the driving unit 20 will be described. For example, the driving unit 20 corresponds to a biasing force generating device. Fig. 2 is an exploded perspective view of the driving unit 20 in Fig. 1, Fig. 3 is an explanatory diagram of a recess 23a of the spiral spring case 23 in Fig. 2, Fig. 4 is a perspective view showing a state in which the spiral spring in Fig. 2 is fixed to the rotating shaft 22, and Fig. 5 is a side view showing a state in which the spiral spring in Fig. 2 is fixed to the rotating shaft 22.

[0027] The driving unit 20 includes a base 21, a rotating shaft 22, a spiral spring case 23, a first spiral spring cover 24, a second spiral spring cover 25, an elastic body 26, and a switching unit 40. The base 21 is a plate-shaped member, and the waist fixing member 14 is attached to the base 21. As a result, the driving unit 20 is held near the waist of the user when the waist fixing member 14 is attached to the waist of the user. The lower end of the upper frame 13B is fixedly connected to the upper end of the base 21. The rotating shaft 22 is provided so as to extend outward from the base 21. The rotating shaft 22 is configured to be switched by the switching unit 40 between a rotatable state and a non-rotatable state about its axis. A lower leg plate 31 is rotatably attached to the rotating shaft 22.

[0028] The spiral spring case 23 is cylindrical with a bottom, and is provided on the outside of the lower leg plate 31. FIG. 3 shows a cross-sectional view of the lower leg plate 31 and the spiral spring case 23 cut along a plane parallel to the main surface of the lower leg plate 31. A substantially fan-shaped recess 23a that spreads downward is formed on the surface of the spiral spring case 23 facing the lower leg plate 31 (see also FIG. 1(b) and FIG. 2). The upper end of the lower leg plate 31 is located within the recess 23a. Due to the recess 23a, a gap 23b is formed in the circumferential direction between the side surface of the lower leg plate 31 and the spiral spring case 23. The spiral spring case 23 corresponds to, for example, a support member.

[0029] 2, the first spiral spring cover 24 and the second spiral spring cover 25 are integrated together to form a circular case that houses the elastic body 26, and are housed and fixed in the spiral spring case 23. Therefore, the elastic body 26 is supported by the spiral spring case 23. The rotating shaft 22 passes through the spiral spring case 23, the first spiral spring cover 24, the second spiral spring cover 25, and the elastic body 26. The spiral spring case 23, the first spiral spring cover 24, and the second spiral spring cover 25 are rotatable with respect to the rotating shaft 22.

[0030] 4 and 5, the elastic body 26 is formed, for example, by a spiral power spring formed by winding a plate-like member. A center portion 26A of the elastic body 26 is fixed to the rotating shaft 22. An outer end portion 26B of the elastic body 26 is fixed to the first power spring cover 24 and the second power spring cover 25. The power spring, which is the elastic body 26, is wound from the outer end portion 26B toward the center portion 26A.

[0031] Next, the switching unit 40 will be described. Fig. 6 is a perspective view of the switching unit 40 in Fig. 2, Fig. 7(a) is a schematic side view of the switching unit 40 when the switching gear 45 is in a non-rotatable state, and Fig. 7(b) is a schematic side view of the switching unit 40 when the switching gear 45 is in a rotatable state. The switching unit 40 has a changeover switch 41, a link plate 42, a changeover lever 43, a changeover spring 44, and a changeover gear 45.

[0032] The changeover switch 41 has a push latch structure, and is configured so that each time the operating portion 41A is pressed, the operating portion 41A switches between a protruding state in which the operating portion 41A protrudes from the switch case 41B and a pressed-in state in which most of the operating portion 41A is pressed into the switch case 41B. The changeover switch 41 corresponds to, for example, a switch mechanism.

[0033] The link plate 42 is provided on the base portion 21 side of the operating portion 41A and the switch case 41B, and one end is connected to the operating portion 41A via a shaft (not shown). Therefore, the link plate 42 moves with the movement of the operating portion 41A. For example, the link plate 42 moves along the left-right direction (front-rear direction) in FIG. 7. The switching lever 43 is located in front of the link plate 42, and is provided to be rotatable about a rotation shaft 43A with respect to the base portion 21. A groove 43b is formed in the end of the switching lever 43 on the opposite side to the rotation shaft 43A. A shaft (not shown) extending from the lower surface of the other end of the link plate 42 is inserted into the groove 43b. A protrusion 43C is provided on the end face of the switching lever 43 on the switching gear 45 side.

[0034] The switching spring 44 is provided in a groove 43b of the switching lever 43. When the operating portion 41A is in a pressed state, the switching spring 44 is pressed by a shaft (not shown) of the link plate 42, and urges the switching lever 43 toward the switching gear 45 and the rotating shaft 22. The switching gear 45 is fixed to the end of the rotating shaft 22 on the base portion 21 side. The switching gear 45 has a number of recesses, which correspond to, for example, a disk portion.

[0035] Next, a method for switching the load in the driving unit 20 of the action assistance device 1 of this embodiment will be described.

[0036] When the user presses the operating part 41A to put the operating part 41A in a pressed state, the switching spring 44 is pressed by the shaft (not shown) of the link plate 42, and the switching spring 44 urges the switching lever 43 toward the switching gear 45. As a result, the protrusion 43C of the switching lever 43 meshes with the switching gear 45. When the switching gear 45 is about to rotate counterclockwise in FIG. 7(a), the switching lever 43 receives a force that tries to rotate clockwise around the rotating shaft 43A due to the positional relationship between the contact surface between the protrusion 43C and the switching gear 45 and the rotating shaft 43A. Therefore, the switching lever 43 does not rotate, and the meshing between the protrusion 43C and the switching gear 45 does not come off, so the rotation of the switching gear 45 is restricted. That is, the switching gear 45 is in a state where it cannot rotate counterclockwise, and the rotating shaft 22 is also in a state where it cannot rotate counterclockwise.

[0037] In this state, when the user bends his / her knees slightly and leans his / her upper body forward from an upright position, the lower leg section 30 rotates around the rotating shaft 22 relative to the upper section 10 and the driving section 20. At this time, the spiral spring case 23 is pushed by the lower leg plate 31 and rotates relative to the rotating shaft 22. Since the center 26A of the elastic body 26 is fixed to the rotating shaft 22, the rotation of the spiral spring case 23 causes the elastic body 26 with the center 26A fixed to be wound up, and a force (biasing force) that rotates in the opposite direction to the rotation is generated in the elastic body 26. The biasing force becomes a torque (assistance torque, assisting force) that assists the movement of the waist when the user moves the waist from bending forward to standing upright. The greater the angle at which the user leans his / her upper body, the greater the assisting torque. In addition, a gap 23b is formed in the circumferential direction between the lower leg plate 31 and the spiral spring case 23. Therefore, when the user's movement angle (the rotation angle of the lower leg section 30 (lower leg plate 31) relative to the base section 21 (spiral spring case 23)) is smaller than a predetermined value (angle θ of the gap 23b), no biasing force is generated and the lower leg section 30 spins freely, and when it exceeds the predetermined value, a biasing force is generated.

[0038] On the other hand, when the user presses the operation part 41A to put the operation part 41A in a protruding state, the link plate 42 is pulled toward the switch case 41B, and the switching lever 43 rotates toward the switch case 41B. As a result, as shown in FIG. 7(b), the protrusion 43C separates from the switching gear 45, and the switching gear 45 becomes rotatable. In this state, when the user bends the knees slightly and leans the upper body forward from an upright posture, the lower leg 30 rotates relative to the upper part 10 and the drive part 20 around the rotating shaft 22. Even if the spiral spring case 23 rotates, the switching gear 45 and the rotating shaft 22 are in a rotatable state, so that the entire elastic body 26 rotates, the elastic body 26 is not wound up, and no urging force is generated by the elastic body 26. In this way, the switching unit 40 can switch between the generation (force-generating state) and non-generation (force-non-generating state) of the biasing force by the elastic body 26 by making the switching gear 45 and the rotating shaft 22 non-rotatable or rotatable. In addition, when the biasing force of the elastic body 26 of a predetermined value or more is applied to the switching gear 45 via the rotating shaft 22 in the state in which the protrusion 43C is biased by the switching spring 44 and meshes with the switching gear 45 as shown in FIG. 7(a), the switching gear 45 may be configured to push the protrusion 43C, compress the switching spring 44, and disengage the meshing between the switching gear 45 and the protrusion 43C. This can reduce the biasing force of the elastic body 26, allowing the switching spring 44 to function as a safety device.

[0039] Next, a biasing force generating device and a motion assisting device according to a second embodiment will be described with reference to the drawings. The same members as those in the motion assisting device 1 of the first embodiment are given the same reference numerals and will not be described. Figures 8(a) and (b) are a side view and a front view of a drive unit 120 of the motion assisting device according to the second embodiment.

[0040] The drive unit 120 includes a pair of base portions 121A, 121B, a connecting portion 122, multiple shafts 123, a first rotating shaft 124, a second rotating shaft 125, a first gear 126, a second gear 127, a first elastic body 128, a second elastic body 129, and a switching unit 140.

[0041] The base portions 121A and 121B are substantially flat plate-shaped and face each other with a gap 121c therebetween. The lower end of the upper frame 13B is fixedly connected to the upper end of the base portion 121A by a connecting portion 122. The gap 121c is formed by a plurality of (for example, five) shafts 123 provided between the pair of base portions 121A and 121B. Members 122 to 129 other than the switching portion 140 are disposed in the gap 121c. The switching portion 140 is located outside the base portion 121A. The base portion 121B is provided with a first support portion 121D that protrudes outward (toward the first gear 126 side).

[0042] The first rotating shaft 124 and the second rotating shaft 125 are rotatably provided on a pair of base parts 121A, 121B. The second rotating shaft 125 is located diagonally upward and rearward from the first rotating shaft 124. A lower leg plate 31 is fixed to the outer end of the first rotating shaft 124, and is rotatable together with the first rotating shaft 124. A switching disk 145, which will be described later, is fixed to the outer end of the second rotating shaft 125, and is rotatable together with the second rotating shaft 125. The second rotating shaft 125 is configured to be in a rotatable state or a non-rotatable state by the switching part 140.

[0043] The first gear 126 is fixed to the first rotating shaft 124 and rotates together with the first rotating shaft 124. The second gear 127 is rotatably provided on the second rotating shaft 125. The second gear 127 is provided with a second support portion 127A that protrudes inward (toward the base portion 121B). The first gear 126 meshes with the second gear 127. The first gear 126 and the second gear 127 correspond to, for example, a transmission portion. The second gear 127 and the second support portion 127A correspond to, for example, a support member.

[0044] The first elastic body 128 and the second elastic body 129 are formed, for example, by a spiral spring formed by winding a plate-like member. The center 128A of the first elastic body 128 is supported by the first rotating shaft 124. The outer end 128B of the first elastic body 128 is supported by the first support portion 121D. The center 129A of the second elastic body 129 is supported by the second rotating shaft 125. The outer end 129B of the second elastic body 129 is supported by the second support portion 127A.

[0045] The switching unit 140 includes a switch 141 , a switching lever 143 , a switching spring 144 , and a switching disk 145 .

[0046] The changeover switch 141 has a push latch structure, and is configured so that each time the operation unit 141A is pressed, the operation unit 141A switches between a protruding state in which the operation unit 141A protrudes outward from the switch case 141B and a pressed-in state in which the operation unit 141A is pushed inward into the switch case 141B and the tip of the operation unit 141A protrudes from the switch case 141B. The changeover switch 141 corresponds to, for example, a switch mechanism.

[0047] The switching lever 143 is located below the changeover switch 141, and is provided rotatably about a rotation shaft 143A with respect to the base portion 121A. The switching lever 143 has a pressed portion 143B that is pressed by the tip of the operation portion 141A, a protrusion 143C that is provided at a position that is approximately point-symmetrical with respect to the pressed portion 143B with respect to the rotation shaft 143A, and a spring connection portion 143D that is located on the opposite side of the protrusion 143C from the rotation shaft 143A side.

[0048] The switching spring 144 is a tension spring, and its upper end is connected to the spring connection portion 143D and its lower end is connected to the base portion 121A. The switching spring 144 urges the spring connection portion 143D downward. The switching disc 145 is fixed to the second rotating shaft 125 and rotates together with the second rotating shaft 125. A recess 145a extending in the circumferential direction is formed in a part of the outer periphery of the switching disc 145 on the switching lever 143 side. The switching disc 145 corresponds to, for example, a disc portion.

[0049] Next, a method for switching the load in the driving unit 120 of the action assistance device 1 of this embodiment will be described.

[0050] When the user presses the operation unit 141A to put it in a protruding state, the switching spring 144 pulls the spring connection unit 143D, the switching lever 143 rotates counterclockwise around the rotating shaft 143A, and the protrusion 143C is pressed against the recess 145a of the switching disk 145. At this time, the protrusion 143C is located at the right (front) end of the recess 145a. In this state, when the user starts from an upright posture and bends the knees slightly and leans the upper body forward, the lower leg unit 30 rotates relative to the upper part 10 and the drive unit 20 around the first rotating shaft 124. At this time, the first rotating shaft 124 rotates, and the first gear 126 also rotates counterclockwise. Since the outer end 128B of the first elastic body 128 is supported by the first support portion 121D, the center portion 128A of the first elastic body 128 is wound around the first rotating shaft 124, the first elastic body 128 is wound and tightened, and a biasing force is generated by the first elastic body 128. At the same time, the rotation of the first gear 126 is transmitted to the second gear 127, and the second gear 127 rotates clockwise.

[0051] Since the outer end 129B of the second elastic body 129 is supported by the second support portion 127A and the center portion 129A of the second elastic body 129 is fixed to the second rotating shaft 125, the second rotating shaft 125, the second elastic body 129, and the switching disk 145 also rotate clockwise when the second gear 127 rotates. When the switching disk 145 rotates and the left (rear) end of the recess 145a abuts against the protrusion 143C, the rotation of the switching disk 145 is restricted. As a result, the second rotating shaft 125 is in a non-rotatable state, and the second gear 127 rotates to tighten the second elastic body 129, generating an urging force by the second elastic body 129. The urging force by the second elastic body 129 is transmitted to the first rotating shaft 124 via the first gear 126 and the second gear 127. In this way, since a biasing force is generated in the first elastic body 128 and the second elastic body 129, the auxiliary torque can be increased. Also, since the recess 145a extends along the circumferential direction, when the user's operating angle (the rotation angle of the second rotating shaft 125 and the switching disc 145 relative to the base part 121A) is smaller than a predetermined value (angle range of the recess 145a), no biasing force is generated by the second elastic body 129 and the lower leg part 30 rotates freely, and when the predetermined value is exceeded, a biasing force is generated by the second elastic body 129.

[0052] On the other hand, when the user presses the operating portion 141A to put it in a pressed state, the tip of the operating portion 141A presses the pressed portion 143B, and the switching lever 143 rotates clockwise against the biasing force of the switching spring 144, and the protrusion 143C moves away from the recess 145a. In this state, when the user bends the knees slightly from an upright posture and leans the upper body forward, the lower leg portion 30 rotates with respect to the upper portion 10 and the driving portion 20 around the first rotating shaft 124. At this time, the first rotating shaft 124 rotates, and the center portion 128A of the first elastic body 128 is wound by the first rotating shaft 124, and a biasing force by the first elastic body 128 is generated. At the same time, the rotation of the first gear 126 is transmitted to the second gear 127, and the second gear 127 rotates clockwise.

[0053] As the second gear 127 rotates, the second rotating shaft 125, the second elastic body 129, and the switching disk 145 also rotate clockwise. Because the protrusion 143C is separated from the recess 145a, the rotation of the switching disk 145 is not restricted, and the entire second elastic body 129 rotates, the second elastic body 129 is not tightened, and no biasing force is generated by the second elastic body 129. In this way, by putting the switching disk 145 into a non-rotatable state or a rotatable state by the switching unit 140, it is possible to switch between the generation of a biasing force by the second elastic body 129 (biasing force generating state) and non-generation (bias force non-generating state).

[0054] The present disclosure is not limited to the configuration of the above-described embodiment. The present invention as defined by the claims is not limited to the above-described embodiment, and is intended to include all modifications within the meaning and scope of the claims.

[0055] The elastic body 26 shown in Figures 4 and 5 is a spiral spring, and the elastic body 128 shown in Figures 8 and 9 is a non-contact spiral spring. When using a spiral spring in the present invention, the form may be either contact or non-contact.

[0056] 9(a) and 9(b) are a side view and a front view of the driving unit 220 of the action-assist device according to the modified example of the second embodiment. In FIG. 9(a), the pair of base units 121A and 121B are omitted. As shown in FIG. 9, the modified example does not include the first elastic body 128. In this configuration, as in the second embodiment, the user presses the operating unit 141A to put it in a protruding state, and then, from an upright position, the user bends the knees slightly and leans the upper body forward, whereby the second elastic body 129 is wound and tightened, and a biasing force is generated by the second elastic body 129. Only the biasing force by the second elastic body 129 is transmitted to the first rotating shaft 124 via the first gear 126 and the second gear 127. On the other hand, when the user presses operation unit 141A to put it in the pressed-in state, and then from an upright position, the user bends the knees slightly and leans the upper body forward, second elastic body 129 is not wound up and no urging force is generated by second elastic body 129. In this modified example as well, switching unit 140 can be used to switch between generation of urging force by second elastic body 129 (urging force generating state) and non-generation of urging force (urging force non-generating state).

[0057] In addition, when the user's motion angle is smaller than a predetermined value, no biasing force is generated in the elastic body 26 and the second elastic body 129 and the lower leg section 30 rotates freely, but the lower leg section 30 may be configured not to rotate freely. The switching disk 145 may not be provided with the recess 145a, and when the position of the second support section 127A is changed and the second gear 127 rotates a predetermined angle, the second support section 127A may come into contact with the outer end section 129B of the second elastic body 129 to tighten the second elastic body 129. [Explanation of symbols]

[0058] 1: Motion assist device 10: Top 11: Backrest 12: Chest piece 12A: Buckle 13A, 13B: Upper frame 14: Waist fixing member 14A: Buckle 20, 120: Drive unit 21, 121A, 121B: Base part 22: Rotating shaft 23: Mainspring case 23a: recess 23b: gap 24: First mainspring cover 25: Second mainspring cover 26: Elastic body 26B: Outer edge 26A: Center 30: Lower limbs 31: Lower limb plate 32: Shaft 33: Lower arm 34: Thigh pad 40: Switching section 41: Changeover switch 41A: Operation unit 41B: Switch case 42: Link board 43: Switch lever 43A: Rotating shaft 43b: Groove 43C: Protrusion 44: Switching spring 45: Switching gear 120: Drive unit 121A, 121B: Base part 121c: gap 121D: first support 122:Connection part 123: Shaft 124: First rotating shaft 125: Second rotating shaft 126: 1st gear 127: 2nd gear 127A:Second support part 128: First elastic body 128A: Center 128B: Outer edge 129: Second elastic body 129A: Center 129B: Outer edge 140: Switching section 141: Changeover switch 141A: Operation unit 141B: Switch case 143: Switch lever 143A: Rotating shaft 143B: Pressed part 143C: Projection 143D: Connection 145: Switching disc

Claims

1. A biasing force generating device, A base portion; A support member rotatably supported on the base portion; an elastic body including a first end and a second end, the first end being supported by the base portion and the second end being supported by the support member, the elastic body being deformed by rotation of the support member relative to the base portion to generate a biasing force; a switching unit that can switch between a biasing force generating state in which a biasing force can be generated by the elastic body and a biasing force non-generating state in which no biasing force is generated by the elastic body.

2. The base portion is provided with a rotating shaft that holds the first end, The switching unit is The rotating shaft is made unrotatable relative to the base portion, and the support member rotates relative to the rotating shaft, causing the elastic body to deform and generate an urging force, thereby putting the elastic body into the urging force generating state, or The repulsion force generating device of claim 1, wherein the rotating shaft is made rotatable relative to the base portion, and the support member rotates together with the rotating shaft so that no biasing force is generated by the elastic body, and the elastic body is switched to the non-biasing state.

3. The switching unit has a switch mechanism having an operation unit, By operating the operation unit, The rotating shaft is brought into a non-rotatable state relative to the base portion, and the elastic body is brought into the biasing force generating state, or The biasing force generating device according to claim 2 , wherein the rotating shaft is switched to a rotatable state relative to the base portion, and the elastic body is switched to the biasing force non-generating state.

4. The switching unit further includes a switching lever and a disk portion having a recess, The switching gear is provided on the rotating shaft, By operating the operation unit, The switching lever is fitted into the recess of the disk portion to make the disk portion non-rotatable, and the rotating shaft is non-rotatable relative to the base portion, so that the elastic body is in the biasing force generating state, or 4. The biasing force generating device according to claim 3, wherein the switching lever is configured to move away from the disk portion, to place the disk portion in a rotatable state, to place the rotating shaft in a rotatable state relative to the base portion, and to place the elastic body in the non-biasing force generating state.

5. The elastic body includes a first elastic body and a second elastic body, The rotating shaft includes a first rotating shaft and a second rotating shaft, the biasing force generating device further includes a transmission unit that transmits the rotation of the first rotating shaft to the second elastic body and transmits the biasing force of the second elastic body to the first rotating shaft, the second elastic body includes the first end and the second end, the first end is held by the second rotating shaft, the second end is supported by the support member, and the support member is rotated relative to the base portion to deform and generate a biasing force, the first elastic body includes a third end and a fourth end, the third end is held by the first rotating shaft, the fourth end is supported by the base portion, and the first elastic body is deformed by rotating the first rotating shaft relative to the base portion to generate a biasing force; The biasing force generating device according to claim 2 , wherein the switching section is configured to be able to switch between generating and not generating a biasing force by the second elastic body.

6. The rotating shaft includes a first rotating shaft and a second rotating shaft, the elastic body has the first end held by the second rotating shaft and the second end supported by the support member, and is deformed by the rotation of the support member relative to the base portion to generate an urging force; the biasing force generating device further includes a transmission unit that transmits rotation of the first rotating shaft to the elastic body and transmits the biasing force of the elastic unit to the first rotating shaft, The biasing force generating device according to claim 2 , wherein the switching section is configured to be able to switch between generating and not generating a biasing force by the elastic body.

7. The biasing force generating device according to claim 1 , wherein the elastic body is a spiral spring.

8. A motion assist device comprising the biasing force generating device according to any one of claims 1 to 7.

9. The action-assist device according to claim 8 , wherein the biasing force generating device is configured to generate a biasing force by the elastic body when a motion angle of a user wearing the action-assist device exceeds a predetermined value.

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