Assistance force generation mechanism for generating assistance force of assistance equipment, and assistance equipment

Abstract

To meet a request to change assistance force of assistance equipment according to intended use.SOLUTION: An assistance force generation mechanism 100 includes: a first energizing part 104 and a second energizing part 108 disposed side by side with each other; a slider 110 provided movably between the first energizing part 104 and the second energizing part 108; and a lock part 112 movable between an engagement position to engage with the slider 110 to prohibit movement of the slider 110 and a non-engagement position to release the engagement and permit the movement of the slider. The assistance force generation mechanism 100 generates assistance force by the action of the first energizing part 104 when the lock part 112 is disposed at the engagement position, and generates assistance force by the action of the first energizing part 104 and the second energizing part 108 when the lock part 112 is disposed at the non-engagement position.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to an assistive force generating mechanism that generates an assistive force for an assistive device that assists in bending and stretching movements of the body, and the assistive device. [Background technology]

[0002] 2. Description of the Related Art Assistive devices that assist bending and stretching movements of the human body are known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-120936 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for the assistive force of an assistive device to be able to be changed depending on the application. [Means for solving the problem]

[0005] In one aspect of the present disclosure, an assistive force generating mechanism for generating an assistive force of an assistive orthosis for assisting bending and stretching movements of a body includes a first biasing portion and a second biasing portion arranged side by side, a slider movably provided between the first biasing portion and the second biasing portion, and a locking portion movable between an engagement position that engages with the slider and prohibits movement of the slider relative to the second biasing portion and a non-engagement position that releases the engagement and allows movement of the slider. The assistive force generating mechanism is configured to generate an assistive force by the action of the first biasing portion when the locking portion is arranged in the engagement position, and to generate an assistive force by the action of the first biasing portion and the second biasing portion when the locking portion is arranged in the non-engagement position. [Brief description of the drawings]

[0006] [Figure 1]FIG. 1 is a diagram showing an auxiliary orthosis according to one embodiment, with the body in an upright position. [Diagram 2] 2 shows the lower arm shown in FIG. 1. [Diagram 3] 2 shows the upper arm shown in FIG. 1. [Figure 4] The link portion shown in FIG. [Diagram 5] FIG. 2 is an enlarged view of the assist force generating mechanism shown in FIG. [Figure 6] 6 is a perspective view of the assist force generating mechanism shown in FIG. 5, illustrating a state in which a locking portion is placed in a non-engaged position. FIG. [Figure 7] FIG. 7 is a cross-sectional view of the assist force generation mechanism shown in FIG. 6. [Figure 8] 6 is a perspective view of the assist force generation mechanism shown in FIG. 5, illustrating a state in which a lock portion is placed at an engagement position. FIG. [Figure 9] FIG. 9 is a cross-sectional view of the assist force generation mechanism shown in FIG. 8. [Figure 10] 6 shows a power section of the actuator shown in FIG. 5. [Figure 11] This shows a state in which the power unit shown in FIG. 10 has rotated the rotating unit. [Figure 12] The supporting device is shown when the body is in a crouching position. [Figure 13] 13 shows a state in which the assist force generating mechanism generates an assist force when the lock portion is disposed in the engagement position. [Figure 14] 13 shows a state in which the assist force generating mechanism generates an assist force when the lock portion is disposed in the disengaged position. [Figure 15] 13 shows a mechanism of an auxiliary device according to another embodiment. [Figure 16] FIG. 16 shows a block diagram of the auxiliary orthosis shown in FIG. [Figure 17] This shows a state in which a person wearing the support device shown in Figure 15 on his / her legs is walking down a slope. [Figure 18] This shows a state in which a body with the assistive device shown in Figure 15 attached to the legs is crossing a slope. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In various embodiments described below, similar elements are given the same reference numerals, and duplicated descriptions will be omitted. In the following description, the Cartesian coordinate system C in the drawings is used as a reference for directions, and for convenience, the positive direction of the x-axis of the coordinate system C is referred to as the forward direction, the positive direction of the y-axis of the coordinate system C is referred to as the leftward direction, and the positive direction of the z-axis is referred to as the upward direction.

[0008] First, an assistive orthosis 10 according to one embodiment will be described with reference to Fig. 1. The assistive orthosis 10 is for assisting the flexion and extension movement of the thigh B1 and shin B2 (i.e., knee flexion and extension movement) of a body B. The thigh B1 and shin B2 are connected via a knee joint B3, and the body B performs knee flexion and extension movement by flexing and extending the thigh B1 and shin B2 at the knee joint B3.

[0009] The assistive orthosis 10 includes a mechanism 12 and mounting bands 14 and 16. Each of the mounting bands 14 and 16 is made of, for example, a natural or chemical fiber cloth, rubber, resin, or a combination of these, and has high flexibility and stretchability so as to fit the body B. In this embodiment, the mounting band 14 is wrapped around the shin B2 and mounted, while the mounting band 16 is wrapped around the thigh B1 and mounted.

[0010] The mechanical unit 12 is disposed between the attachment bands 14 and 16. The mechanical unit 12 will be described below with reference to Figs. 1 to 5. The mechanical unit 12 has arms 18 and 20, a link unit 22, and an assist force generating mechanism 100. The arm 18 is attached to the attachment band 14, and is attached to the shin B2 via the attachment band 14.

[0011] 2, the arm 18 is an integral flat plate member made of a metal such as aluminum, and has a main body portion 26, a gear portion 28, and an extension portion 30. The main body portion 26 has an upper end portion 32 and a lower end portion 34 opposite to the upper end portion 32, and extends from the upper end portion 32 to the lower end portion 34 along the axis A1.

[0012] More specifically, the main body 26 has a rectangular first portion 36 extending straight along the axis A1, and a generally sector-shaped second portion 38 extending upward from an upper end of the first portion 36. The first portion 36 defines a lower end 34, while the second portion 38 defines an upper end 32. The first portion 36 is attached to the mounting band 14 (FIG. 1). The second portion 38 widens as it extends upward from the upper end of the first portion 36.

[0013] A shaft 40 is provided at the upper end 32. The shaft 40 is, for example, cylindrical, and is formed integrally with the upper end 32 so as to extend rightward from the upper end 32. The upper end 32 has an arc-shaped outer circumferential surface 42. The outer circumferential surface 42 is disposed substantially coaxially with the shaft 40.

[0014] Gear portion 28 has a predetermined diameter R1 (e.g., a pitch diameter) and is formed integrally with upper end portion 32. More specifically, gear portion 28 has a plurality of teeth 28a aligned in the circumferential direction of an outer circumferential surface 42 of upper end portion 32. Each of teeth 28a is formed integrally with outer circumferential surface 42 so as to protrude radially outward from outer circumferential surface 42.

[0015] The extension portion 30 is formed integrally with the upper end portion 32 of the main body portion 26 so as to extend outward from the upper end portion 32. More specifically, the extension portion 30 is disposed adjacent to the front side of the gear portion 28 at the upper end portion 32, and extends straight from the upper end portion 32 along the axis A2. The axis A2 is inclined at an angle θ1 with respect to the axis A1 of the main body portion 26. In this embodiment, the angle θ1 is an acute angle (for example, θ1=10° to 60°).

[0016] 3, arm 20 is an integral flat plate member made of a metal such as aluminum, and has a main body portion 44 and a gear portion 46. Main body portion 44 has an upper end portion 48 and a lower end portion 50 opposite to upper end portion 48, and extends straight from upper end portion 48 to lower end portion 50 along axis A3.

[0017] A shaft 52 is provided at the lower end portion 50. The shaft 52 is, for example, cylindrical and is integrally formed with the lower end portion 50 so as to extend rightward from the lower end portion 50. Further, the lower end portion 50 has an arcuate outer peripheral surface 54. The outer peripheral surface 54 is arranged substantially coaxially with the shaft 52.

[0018] The gear portion 46 has a predetermined diameter R2 (for example, pitch diameter) and is integrally formed with the lower end portion 50. More specifically, the gear portion 46 has a plurality of tooth portions 46a aligned in the circumferential direction of the outer peripheral surface 54 of the lower end portion 50. Each tooth portion 46a is integrally formed with the outer peripheral surface 54 so as to protrude radially outward from the outer peripheral surface 54.

[0019] The tooth portion 46a engages with the tooth portion 28a (FIG. 2) of the gear portion 28. In the present embodiment, the diameter R2 of the gear portion 46 is different from the diameter R1 of the gear portion 28. More specifically, the diameter R2 of the gear portion 46 is smaller than the diameter R1 of the gear portion 28 (R2 < R1), and the ratio of the diameter R2 to the diameter R1 is set to, for example, R2:R1 = 12:17.

[0020] Referring to FIG. 4, the link portion 22 is an integrally formed flat plate member made of a metal such as aluminum, and has a main body portion 56 and a lever portion 58. The main body portion 56 extends straight along the axis A4, and its lower end portion 56a is rotatably connected to the arm 18, and its upper end portion 56b is rotatably connected to the arm 20. More specifically, a through hole 60 is formed in the lower end portion 56a of the main body portion 56, while a through hole 62 is formed in the upper end portion 56b of the main body portion 56.

[0021] The shaft 40 (FIGS. 1 and 2) of the arm 18 is rotatably inserted into the through hole 60 of the main body portion 56, and a fastening member (not shown) such as a bolt is fastened to the shaft 40. Thereby, the upper end portion 32 of the arm 18 is connected to the lower end portion 56a of the main body portion 56 so as to be relatively rotatable around the central axis of the shaft 40.

[0022] On the other hand, the shaft 52 (FIGS. 1 and 3) of the arm 20 is rotatably inserted into the through-hole 62 of the main body 56, and a fastener (not shown) such as a bolt is fastened to the shaft 52. As a result, the lower end 50 of the arm 20 is connected to the upper end 56b of the main body 56 so as to be relatively rotatable about the central axis of the shaft 52.

[0023] The lever portion 58 is formed integrally with the lower end portion 56a of the main body portion 56 so as to extend from the lower end portion 56a along the axis A5. The axis A5 is inclined at an angle θ2 with respect to the axis A4. In this embodiment, the angle θ2 is an acute angle (for example, θ2=30° to 80°).

[0024] Lever portion 58 has a side surface 58a that extends in a curved shape. Side surface 58a extends in a curved shape so as to bulge outward from its base end toward its tip end. Side surface 58a may be an arcuate surface having a predetermined radius of curvature, or may be a combination of multiple arcuate surfaces each having multiple radii of curvature.

[0025] The assistive force generation mechanism 100 generates an assistive force Fa for the assistive orthosis 10. In this embodiment, the assistive force generation mechanism 100 is provided on the extension portion 30 of the arm 18, as shown in Fig. 1. The assistive force generation mechanism 100 will be described below with reference to Figs. 5 to 7. The assistive force generation mechanism 100 includes a fixed shaft 102, a first biasing portion 104, a housing 106, a second biasing portion 108 (Fig. 7), a slider 110, a lock portion 112, and an actuator 114.

[0026] The fixed shaft 102 has a shaft portion 102a extending straight along an axis A6, and a flange portion 102b provided to protrude outward from the upper end of the shaft portion 102a and fixed to the extension portion 30 of the arm 18. The axis A6 may be disposed so as to be parallel to the axis A2 (FIGS. 1 and 2) of the extension portion 30.

[0027] The first biasing portion 104 is inserted between the slider 110 and the flange portion 102b. In the present embodiment, the first biasing portion 104 is a compression coil spring having a first spring constant k1, and expands and contracts in the direction of the axis A6. The first biasing portion 104 is positioned to extend in the direction of the axis A6 by having the shaft portion 102a inserted therethrough. When the first biasing portion 104 is compressed by a displacement amount x in the direction of the axis A6, a biasing force F1 (= k1·x) is generated as its reaction force.

[0028] The housing 106 is hollow and receives a part of the shaft portion 102a and the slider 110. Specifically, the housing 106 has a substantially rectangular bottom portion 106a, a cylindrical side wall portion 106b extending from the bottom portion 106a, and a flange portion 106c extending outward from the upper end of the side wall portion 106b. The side wall portion 106b has a rectangular outer shape and, together with the bottom portion 106a, defines a quadrangular prism-shaped internal space S.

[0029] As shown in FIG. 7, the second biasing portion 108 is housed in the internal space S of the housing 106 and is inserted between the slider 110 and the bottom portion 106a. In the present embodiment, the second biasing portion 108 is a compression coil spring having a second spring constant k2 (≠ k1) different from the above-described first spring constant k1, and expands and contracts in the direction of the axis A6. The second biasing portion 108 is positioned to extend in the direction of the axis A6 by having the shaft portion 102a inserted therethrough. Thus, the first biasing portion 104 and the second biasing portion 108 are arranged to be aligned with each other in the direction of the axis A6.

[0030] When the second biasing portion 108 is compressed by a displacement amount x in the direction of the axis A6, a biasing force F2 (= k2·x) is generated as its reaction force. Here, in the present embodiment, the second spring constant k2 is smaller than the above-described first spring constant k1 (k2 < k1). Therefore, when the first biasing portion 104 and the second biasing portion 108 are compressed by a displacement amount x in the direction of the axis A6, biasing forces F1 and F2 having different magnitudes are generated respectively (specifically, F1 > F2).

[0031] The slider 110 is provided between the first biasing portion 104 and the second biasing portion 108 so as to be movable along the axis A6. Specifically, the slider 110 has a slider body 110a and a plurality of claw portions 110b. The slider body 110a has a substantially rectangular outer shape, and a through-hole 110c (FIG. 7) is formed in the center thereof, penetrating the slider body 110a in the direction of the axis A6.

[0032] A part of the slider body 110a is received in the internal space S of the housing 106 so as to be movable in the direction of the axis A6. In this embodiment, the slider body 110a and the internal space S (i.e., the inner surface of the side wall portion 106b) have corresponding rectangular outer shapes. With this configuration, the slider body 110a is restricted from rotating about the axis A6 with respect to the housing 106, while the movement of the slider body 110a in the direction of the axis A6 is guided by the side wall portion 106b.

[0033] The shaft portion 102a is inserted into the through hole 110c so as to be relatively slidable, thereby allowing the slider 110 to slide on the shaft portion 102a in the direction of the axis A6. In addition, a ring-shaped flange portion 110d (FIG. 6) protruding outward from the upper end portion is integrally formed on the upper end portion of the slider body 110a.

[0034] The first biasing portion 104 has an upper end that abuts against the flange portion 102b of the fixed shaft 102, and a lower end that abuts against the flange portion 110d of the slider 110. The second biasing portion 108 has an upper end that abuts against the lower end surface of the slider main body 110a, and a lower end that abuts against the bottom portion 106a of the housing 106.

[0035] Each of the claws 110b is integrally formed with the flange portion 110d of the slider body 110a so as to protrude outward from the flange portion 110d. In this embodiment, a total of four claws 110b are arranged at approximately equal intervals in the circumferential direction of the flange portion 110d.

[0036] The locking portion 112 is disposed adjacent to the upper side of the flange portion 106c of the housing 106 so as to be rotatable around the axis A6. Specifically, the locking portion 112 has a ring portion 112a, a plurality of groove portions 112b, and an engagement portion 112c. The ring portion 112a is a substantially cylindrical member, and is provided so as to be rotatable around the axis A6 so as to surround the slider main body 110a.

[0037] Each of the grooves 112b is formed in the ring portion 112a so as to extend parallel to the direction of the axis A6 (i.e., the moving direction of the slider 110). In this embodiment, a total of four grooves 112b are arranged at approximately equal intervals in the circumferential direction of the ring portion 112a so as to correspond to the positions of the claws 110b of the slider 110. Each of the grooves 112b is formed to open upward at the upper end of the ring portion 112a so as to be able to receive the corresponding claws 110b therein. The engagement portion 112c has an approximately U-shaped outer shape when viewed from above, and is formed integrally with the ring portion 112a so as to protrude outward from the lower end of the ring portion 112a.

[0038] The locking portion 112 (i.e., the ring portion 112a) rotates around the axis A6 between an engagement position P1 and a disengagement position P2. Figures 6 and 7 show the locking portion 112 in a state where it is disposed in the disengagement position P2. When it is disposed in the disengagement position P2, the groove portion 112b of the locking portion 112 and the corresponding claw portion 110b are aligned in the direction of the axis A6.

[0039] 8 and 9 show a state in which the locking portion 112 is disposed at the engagement position P1. When disposed at the non-engagement position P2, the grooves 112b of the locking portion 112 are shifted in the circumferential direction from the corresponding claws 110b. As a result, each of the claws 110b faces the upper end surface of the ring portion 112a.

[0040] The actuator 114 drives the lock portion 112 between an engaged position P1 and a disengaged position P2. Specifically, the actuator 114 has an actuator housing 116, a rotating portion 118, and a power portion 120 (FIG. 10). The actuator housing 116 is hollow, and is fixed to the housing 106 via a mounting fixture 122. The actuator housing 116 accommodates therein the power portion 120, which will be described later.

[0041] The rotating part 118 is a rod-shaped member extending linearly, and is provided in the actuator housing 116 so as to be rotatable about an axis A7 perpendicular to the axis A6. The upper end of the rotating part 118 is inserted into the engaging part 112c of the lock part 112, and thereby engages with the engaging part 112c.

[0042] The power unit 120 rotates the rotating unit 118 to rotate the lock unit 112 between an engagement position P1 and a disengagement position P2 via the rotating unit 118. More specifically, as shown in Fig. 10, the power unit 120 has a lever unit 124, a base unit 126, a spring 128, and a pair of shape memory alloys (SMAs) 130a and 130b.

[0043] Lever portion 124 is fixed integrally to rotating portion 118 and rotates about axis A7 together with rotating portion 118. Base portion 126 is disposed opposite lever portion 124 so as to move toward and away from lever portion 124. Spring 128 is interposed between lever portion 124 (or rotating portion 118) and base portion 126 and biases lever portion 124 and base portion 126 so as to maintain a constant distance between lever portion 124 and base portion 126.

[0044] The pair of SMAs 130a and 130b are stretched between the lever portion 124 and the base portion 126. The upper ends of the SMAs 130a and 130b are connected to the rotating portion 118 via the lever portion 124. Each of the SMAs 130a and 130b contracts in its length direction when a current is applied, and expands to its original length when the current is stopped.

[0045] Power unit 120 utilizes the elasticity of SMAs 130a and 130b to generate power to rotate rotating unit 118. For example, from the state shown in Fig. 10, a current is applied to the right-hand SMA 130b of the pair of SMAs 130a and 130b. This causes SMA 130b to contract, and applies a torque to rotating unit 118 via lever unit 124 in the clockwise direction as viewed from the front side of the paper surface of Fig. 10.

[0046] As a result, rotating portion 118 rotates about axis A7 by a predetermined angle θ3 (for example, θ3 ≈ 30°) from initial position P3 shown in Fig. 10, and is disposed at rotation position P4 shown in Fig. 11. At this time, tension is applied to left SMA 130a, and SMA 130a is pulled in its length direction and slightly elongated.

[0047] On the other hand, when the current to SMA 130b is stopped, SMA 130b gradually expands in its length direction, while SMA 130a contracts due to its restoring force as the tension acting thereon is released. This causes rotating portion 118 to rotate counterclockwise about axis A7, returning from rotation position P4 shown in Fig. 11 to initial position P3 shown in Fig. 10. Spring 128 maintains the distance between lever portion 124 and base portion 126, thereby preventing overload from being applied to SMAs 130a and 130b which expand and contract in this manner. This makes it possible to prevent damage to SMAs 130a and 130b.

[0048] As the rotating part 118 rotates between the initial position P3 and the rotation position P4 by the action of the power part 120, the lock part 112 rotates between the engagement position P1 (FIG. 6) and the disengagement position P2 (FIG. 8). Note that in FIGS. 10 and 11, the rotating part 118 is shown by a dotted line for ease of understanding.

[0049] Next, the function of the support orthosis 10 will be described. Fig. 1 shows an upright position in which the thigh B1 and the shin B2 are extended and stand upright. In this upright position, the arms 18 and 20 are placed in the extended position shown in Fig. 1. When placed in the extended position, the axis A1 of the arm 18, the axis A3 of the arm 20, and the axis A4 of the main body 56 of the link part 22 are approximately parallel to each other.

[0050] Furthermore, the lever portion 58 is disposed at a first relative position RP1 with respect to the arm 18. At this time, the first biasing portion 104 and the second biasing portion 108 of the assistive force generation mechanism 100 are maintained in an extended state, and the assistive force generation mechanism 100 does not generate the assistive force Fa. In the upright posture shown in FIG. 1, the body B faces forward.

[0051] On the other hand, Fig. 12 shows a squatting posture in which the thigh B1 and the shin B2 are bent at the knee joint B3. In Fig. 12, the attachment bands 14 and 16 are shown by dotted lines for ease of understanding. In the squatting posture shown in Fig. 12, the arms 18 and 20 are disposed in a bent position. When disposed in the bent position, the axis A1 of the arm 18, the axis A3 of the arm 20, and the axis A4 of the main body 56 of the link part 22 are not parallel to each other, and the axes A1 and A3 form an acute angle. Also, the lever part 58 is disposed in a second relative position RP2 with respect to the arm 18.

[0052] 12, the arm 20 rotates relative to the link portion 22 about the central axis of the shaft 52 in a counterclockwise direction as viewed from the right side, while the arm 18 rotates relative to the link portion 22 about the central axis of the shaft 40 in a clockwise direction as viewed from the right side. As a result, the arms 18 and 20 bend from an extended position to a bent position.

[0053] This bending motion of the arms 18 and 20 is guided by the engagement between the gear portion 28 of the arm 18 and the gear portion 46 of the arm 20, and by the link portion 22 that connects the arms 18 and 20 so as to be capable of relative rotation. As a result, during the bending motion of the arms 18 and 20, the lower end portion 50 of the arm 20 is guided so as to revolve around the shaft 40 disposed in the arm 18 in the counterclockwise direction as viewed from the right side.

[0054] On the other hand, as the arms 18 and 20 bend from the extended position to the bent position, the lever portion 58 rotates relative to the arm 18 from a first relative position RP1 to a second relative position RP2 around the central axis of the shaft 40 in the counterclockwise direction as viewed from the right side. As the lever portion 58 rotates relative to the arm 18 in this manner, the side surface 58a of the lever portion 58 slides on the bottom portion 106a of the housing 106 of the assistive force generating mechanism 100, and pushes the bottom portion 106a in the first direction D1 of the axis A6 (i.e., the axis A2).

[0055] As a result, the housing 106 of the assistive force generation mechanism 100 is displaced in the first direction D1. It is assumed that the lock portion 112 (ring portion 112a) is located at the engagement position P1 (FIGS. 8 and 9) at this time. In this case, the housing 106 pushed in the first direction D1 by the lever portion 58 is displaced in the first direction D1 together with the lock portion 112.

[0056] However, the upper end surface of the ring portion 112a arranged at the engagement position P1 engages with the claw portion 110b of the slider 110, thereby prohibiting the slider 110 from moving relative to the housing 106, the second biasing portion 108, and the lock portion 112. Therefore, in this case, the second biasing portion 108 is not substantially compressed in the first direction D1.

[0057] In this state, when the housing 106 is further pushed in the first direction D1 by the lever portion 58, the housing 106, the second biasing portion 108, the locking portion 112, and the slider 110 are displaced together in the first direction D1, compressing the first biasing portion 104 in the first direction D1, as shown in FIG. 13.

[0058] Then, the first biasing portion 104 applies a biasing force F1 acting in a second direction D2 opposite to the first direction D1 as a reaction force to the lever portion 58 via the slider 110, the lock portion 112, and the housing 106. The biasing force F1 thus applied to the lever portion 58 by the action of the first biasing portion 104 is an assisting force Fa of the assist orthosis 10 that assists the flexion and extension movement of the thigh B1 and the shin B2. 1 That is, when the lock portion 112 is disposed at the engagement position P1, the auxiliary force Fa 1 is the biasing force F1 generated by the action of the first biasing portion 104.

[0059] On the other hand, it is assumed that the lock portion 112 (ring portion 112a) is disposed at the non-engagement position P2 (FIGS. 6 and 7). In this case, the housing 106, which is pushed in the first direction D1 by the lever portion 58, is displaced in the first direction D1 together with the lock portion 112. At this time, since the lock portion 112 is disposed at the non-engagement position P2, the claw portion 110b of the slider 110 relatively enters into the groove portion 112b formed in the lock portion 112, which moves in the first direction D1 together with the housing 106.

[0060] This allows the slider 110 to move relative to the housing 106, the second biasing portion 108, and the locking portion 112. As a result, the housing 106 and the locking portion 112 move relative to the slider 110 in the first direction D1, and this causes the second biasing portion 108 (FIG. 14) interposed between the slider 110 and the bottom portion 106a in the housing 106 to be compressed in the first direction D1.

[0061] In this state, when the housing 106 is further pushed in the first direction D1 by the lever portion 58, the second biasing portion 108 is further compressed, and the housing 106, the slider 110, and the lock portion 112 are displaced in the first direction D1. As a result, as shown in FIG. 14, the first biasing portion 104 is also compressed in the first direction D1.

[0062] Thus, when the first biasing portion 104 is compressed, the first biasing portion 104 applies a biasing force F1 acting in the second direction D2 to the lever portion 58 via the slider 110, the second biasing portion 108, and the housing 106 according to its displacement amount x. Also, the second biasing portion 108 also applies a biasing force F2 acting in the second direction D2 to the lever portion 58 via the housing 106 according to its displacement amount x.

[0063] The biasing force F12 applied to the lever portion 58 by the actions of the first biasing portion 104 and the second biasing portion 108 is equivalent to the biasing force generated by the action of the combined spring SR of the first biasing portion 104 and the second biasing portion 108 connected in series to each other, and is the assisting force Fa of the assist device 10 that assists the flexion and extension movements of the thigh portion B1 and the shin portion B2. 12 That is, when the locking portion 112 is disposed at the non-engagement position P2, the assisting force Fa 12 becomes the biasing force F12 generated by the actions of the first biasing portion 104 and the second biasing portion 108 (that is, the combined spring RS).

[0064] Since the spring constant k12 of this combined spring SR is k12 = k1·k2 / (k1 + k2) < k1, the assisting force Fa generated by the combined spring SR 12 can be smaller than the above-described assisting force Fa 1 (Fa 12 > Fa 1 ). Thus, in this embodiment, the actuator 114 selectively disposes the locking portion 112 at the engagement position P1 or the non-engagement position P2, so that the assisting force Fa generated as the assisting force generation mechanism 100 can be switched between the assisting force Fa 1 and the assisting force Fa 12 .

[0065] Conversely, when body B moves from the crouching position shown in Fig. 12 to the standing position shown in Fig. 1, arm 20 rotates relative to link portion 22 around the central axis of shaft 52 in a clockwise direction as viewed from the right side, while arm 18 rotates relative to link portion 22 around the central axis of shaft 40 in a counterclockwise direction as viewed from the right side. As a result, arms 18 and 20 extend from the bent position to the extended position.

[0066] This extension movement of the arms 18 and 20 is guided by the engagement of the gear units 28 and 46 and the link unit 22. As a result, during the extension movement of the arms 18 and 20, the lower end unit 50 of the arm 20 is guided to revolve around the shaft 40 provided on the arm 18 in a clockwise direction as viewed from the right side. In this manner, the link unit 22 connects the arms 18 and 20 so that they can be bent and extended between the extended position and the bent position, and the gear units 28 and 46, together with the link unit 22, guide the bending and extension movement of the arms 18 and 20.

[0067] As the arms 18 and 20 extend from the bent position to the extended position, the lever portion 58 rotates relative to the arm 18 around the central axis of the shaft 40 in the clockwise direction as viewed from the right side, from the second relative position RP2 to the first relative position RP1. Here, in this embodiment, as described above, the assisting force generating mechanism 100 generates the assisting force Fa (specifically, the assisting force Fa 1 Or Fa 12 ) is added.

[0068] As a result, the lever portion 58 is urged from the second relative position RP2 toward the first relative position RP1, and as a result, the lower end portion 50 of the arm 20 is urged to revolve around the central axis of the shaft 40 in the clockwise direction as viewed from the right side through the link portion 22. In this way, the assist force generating mechanism 100 applies the assist force Fa to the lever portion 58, thereby urging the arms 18 and 20 from the bent position toward the extended position.

[0069] In this way, the assist device 10 can assist the body B in standing up from a crouching position to an upright position by the assist force Fa generated by the assist force generating mechanism 100. As a result, the body B can stand up more easily. Then, the body B moves to the upright position shown in FIG. 1, and the arms 18 and 20 return to the extended positions.

[0070] As described above, in this embodiment, the assist force generating mechanism 100 comprises the first biasing portion 104 and the second biasing portion 108 arranged side by side, the slider 110 movably provided between the first biasing portion 104 and the second biasing portion 108, and the locking portion 112 movable between an engagement position P1 that engages with the slider 110 and prohibits movement of the slider 110 relative to the second biasing portion 108, and a non-engagement position P2 that releases the engagement and permits the movement of the slider 110.

[0071] When the lock portion 112 is disposed in the engagement position P1, the assist force generating mechanism 100 generates an assist force Fa by the action of the first biasing portion 104. 1 On the other hand, when the locking portion 112 is disposed in the non-engagement position P2, the first biasing portion 104 and the second biasing portion 108 generate an auxiliary force Fa 12 is generated (Figure 14).

[0072] According to this configuration, by selectively disposing the locking portion 112 at the engagement position P1 or the non-engagement position P2, the auxiliary force Fa generated by the auxiliary force generating mechanism 100 is 1 and auxiliary force Fa 12 This allows the auxiliary force Fa to be variable depending on the application.

[0073] In this embodiment, the assist force generating mechanism 100 further includes an actuator 114 that drives the locking portion 112 between the engagement position P1 and the non-engagement position P2. According to this configuration, the locking portion 112 is placed at the engagement position P1 or the non-engagement position P2 by the operation of the actuator 114, and the assist force Fa is generated as the assist force Fa 1 and auxiliary force Fa12 You can switch between.

[0074] In this embodiment, the locking portion 112 is provided to be rotatable about an axis A6 parallel to the moving direction of the slider 110 between an engagement position P1 and a non-engagement position P2. The actuator 114 is provided to be rotatable about an axis A7 perpendicular to the axis A6, and has a rotating portion 118 that engages with the locking portion 112 (specifically, the engaging portion 112c), and a power portion 120 that rotates the rotating portion 118 to rotate the locking portion 112 between the engagement position P1 and the non-engagement position P2 via the rotating portion 118.

[0075] According to this configuration, the actuator 114 can place the locking part 112 at the engagement position P1 or the non-engagement position P2 by rotating the rotating part 118 with the power part 120. This makes it possible to move the locking part 112 to the engagement position P1 or the non-engagement position P2 with a relatively small driving force, and also makes it possible to make the configuration of the rotating part 118 and the locking part 112 compact.

[0076] In the present embodiment, the power unit 120 has shape memory alloys 130a and 130b that are connected to the rotating unit 118 and expand and contract in response to an electric current to rotate the rotating unit 118. Here, the shape memory alloys 130a and 130b are relatively light in weight and can generate a driving force to rotate the rotating unit 118 without generating noise. Therefore, the weight of the assisting force generation mechanism 100 can be reduced and the quietness of the operation of the assisting force generation mechanism 100 can be improved.

[0077] In this embodiment, the slider 110 has a slider body 110a and a claw portion 110b protruding outward from the slider body 110a. The lock portion 112 has a ring portion 112a that surrounds the slider body 110a and is rotatable between an engagement position P1 and a non-engagement position P1, and a groove portion 112b formed in the ring portion 112a so as to extend parallel to the movement direction of the slider 110 (i.e., the axis A6).

[0078] When the ring portion 112a is located at the engagement position P1, the claw portion 110b engages with the ring portion 112a of the lock portion 112, thereby prohibiting the movement of the slider 110 relative to the second biasing portion 108, whereas when the ring portion 112a is located at the non-engagement position P2, the claw portion 110b enters the groove portion 112b, thereby permitting the movement of the slider 110. According to this configuration, the movement of the slider 110 can be prohibited or permitted by the lock portion 112 with a relatively simple configuration. Therefore, the configuration of the slider 110 can be made compact by the lock portion 112.

[0079] In this embodiment, the first biasing unit 104 includes a spring having a first spring constant k1, and the second biasing unit includes a spring having a second spring constant k2 (≠k1) different from the first spring constant k1. With this configuration, by using two springs with different spring constants, the first biasing unit 104 and the second biasing unit 108 that can generate forces of different magnitudes can be easily configured. Therefore, the manufacturing cost of the assist force generation mechanism 100 can be reduced.

[0080] In addition, in this embodiment, the first urging portion 104 can generate a larger urging force F1 (>F2) than the second urging portion 108. More specifically, by setting the first spring constant k1 of the first urging portion 104 to a value larger than the second spring constant k2 of the second urging portion 108, the urging force F1 (=k1·x) of the first urging portion 104 can be larger than the urging force F2 (=k2·x) of the second urging portion 108. According to this configuration, by selectively disposing the lock portion 112 at the engagement position P1 or the non-engagement position P2 depending on the application, the auxiliary force Fa can be set to the auxiliary force Fa 1 and the auxiliary force Fa 1 The auxiliary force Fa is significantly smaller than 12 You can switch between.

[0081] In this embodiment, the assistive orthosis 10 includes an arm 18 attached to a part B2 (specifically, the shin) of the body B, an arm 20 attached to a part B1 (specifically, the thigh) of the body B, a link section 22 that connects the arms 18 and 20 so that they can be bent and extended between an extended position and a bent position, and an assistive force generating mechanism 100 that applies an assistive force Fa to the link section 22 (specifically, the lever section 58) to urge the arms 18 and 20 from the bent position to the extended position. With this configuration, it is possible to realize the assistive orthosis 10 that can switch the assistive force Fa depending on the application as described above.

[0082] The actuator 114 has an operation unit (e.g., a switch, a push button, or a touch panel) that turns the current to the SMA 130b on or off, and the user of the assistive device 10 may manually operate the operation unit to turn the current to the SMA 130b on or off. In this case, the user can manually operate the actuator 114 to arbitrarily place the locking unit 112 in the engagement position P1 or the non-engagement position P2.

[0083] In this embodiment, the power unit 120 (FIG. 10) has been described as having a pair of SMAs 130a and 130b. However, this is not limiting, and the power unit 120 may have, for example, an elastic filament (e.g., a rubber band) instead of the SMA 130a. Even in this case, the power unit 120 can achieve the rotational movement of the rotation unit 118 as shown in FIGS. 10 and 11.

[0084] A sliding material with a low coefficient of friction (e.g., resin) may be provided at the contact portion between side surface 58a of lever portion 58 and bottom portion 106a of housing 106. With this configuration, side surface 58a of lever portion 58 can slide more smoothly on bottom portion 106a when arms 18 and 20 bend and extend between the bent position and the extended position.

[0085] In addition, while the arms 18 and 20 move from the extended position to the bent position, the side 58a abuts against the bottom 106a while sliding against it, but the curved shape of the side 58a may be determined so that the normal direction of the side 58a at the abutment point between the side 58a and the bottom 106a is approximately parallel to the axis A2 (or A6).

[0086] According to this configuration, the side surface 58a can always effectively apply a force to the bottom portion 106a in the first direction D1 while the arms 18 and 20 move from the extended position to the bent position. This makes it possible to effectively compress the first biasing portion 104 and the second biasing portion 108. On the other hand, the first biasing portion 104 and the second biasing portion 108 can apply a force to the side surface 58a of the lever portion 58 in the second direction D2 that is parallel to the normal direction of the side surface 58a, so that the lever portion 58 can be effectively biased toward the first relative position RP1.

[0087] The assistive orthosis 10 may have a pair of mechanical parts 12, one of which is disposed on the left side of the thigh B1, shin B2, and knee joint B3, while the other of the pair of mechanical parts 12 is disposed on the right side of the thigh B1, shin B2, and knee joint B3. In this case, the pair of mechanical parts 12 may have a symmetrical structure.

[0088] The above-described configuration of the assistive force generation mechanism 100 is merely an example, and various modifications can be made. For example, the actuator 114 may be omitted from the assistive force generation mechanism 100, and the user may manually place the lock portion 112 in the engagement position P1 or the disengagement position P2. The actuator 114 may have a motor (e.g., a micromotor) that rotates the rotation portion 118, instead of the SMAs 130a and 130b.

[0089] Further, the locking portion 112 is not limited to the form having the ring portion 112a and the groove portion 112b. For example, the locking portion 112 may have a pin that moves forward and backward in the radial direction with respect to the slider 110 and detachably engages with an engagement hole formed in the slider 110, or may have any other structure capable of prohibiting the movement of the slider 110 with respect to the second biasing portion 108 (or the housing 106).

[0090] Also, in the above-described embodiment, the case where the first biasing portion 104 can generate a biasing force F1 (>F2) larger than the second biasing portion 108 has been described. However, the present invention is not limited to this, and the first biasing portion 104 may be configured to generate the same biasing force F1 (=F2) as the second biasing portion 108, or a biasing force F1 (<F2) smaller than the second biasing portion 108, with respect to a common displacement amount x.

[0091] In this case, the first spring constant k1 may be set to the same value as the second spring constant k2 or a value smaller than the second spring constant k2. Note that at least one of the first biasing portion 104 and the second biasing portion 108 is not limited to a spring, and may have any structure capable of generating a biasing force acting in the second direction D2, such as a pneumatic cylinder or a pair of magnets repelling each other.

[0092] Next, with reference to FIGS. 15 and 16, an auxiliary device 70 according to another embodiment will be described. The auxiliary device 70 is different in that it further includes the control unit 72, the sensor 74 (FIG. 16), and the power source 76 in addition to the above-described auxiliary device 10. In FIG. 15, the mounting bands 14 and 16 are not shown for ease of understanding. The power source 76 is fixed to the arm 18 (specifically, the second portion 38 of the main body portion 26) and supplies power to the control unit 72 and the power unit 120 (specifically, the SMA 130b) of the actuator 114. For example, the power source 76 may have a dry battery.

[0093] The sensor 74 detects the posture of the body B. Here, as shown in Fig. 17, when the body B walks up a slope, it walks by alternately putting out the right leg B11 and the left leg B12 forward on the slope (i.e., upward on the slope). Fig. 17 shows a posture in which the right leg B11 is put out forward on the slope.

[0094] In this posture, the flexion angle between the thigh B1 and shin B2 of the right leg B11 is smaller than the flexion angle between the thigh B1 and shin B2 of the left leg B12, and the thigh B1 and shin B2 of the right leg B11 are bent more deeply, while the thigh B1 and shin B2 of the left leg B12 are essentially extended.

[0095] In this embodiment, the sensor 74 detects the posture of the leg B11 according to the degree of bending. As an example, the sensor 74 has a pressure sensor 74A provided on the sole B4 of the leg B11. Here, when the body B is walking on a slope, the pressure applied to the sole B4 changes when the leg B11 is located in front of the slope (i.e., when the thigh B1 and shin B2 of the leg B11 are deeply bent) and when the leg B11 is located on the rear side of the slope (i.e., when the thigh B1 and shin B2 of the leg B11 are extended). The pressure sensor 74A detects the pressure that changes according to the posture of the leg B11 as detection data α.

[0096] As another example, the sensor 74 has a gyro sensor 74B provided on the instep B5 of the leg B11. When the body B is walking on a slope and the leg B11 moves back and forth on the slope, the inclination angle of the instep B5 changes accordingly. The gyro sensor 74B detects the inclination angle that changes in accordance with the posture of the leg B11 as detection data α.

[0097] As yet another example, the sensor 74 has an angle sensor 74C that measures the flexion angle of the knee joint B3 or the ankle B6 of the leg B11. When the body B is walking on a slope, the flexion angle of the knee joint B3 or the ankle B6 changes depending on whether the leg B11 is positioned in front of the slope or behind the slope. The angle sensor 74C detects the flexion angle that changes in accordance with the posture of the leg B11 as detection data α.

[0098] As yet another example, the sensor 74 has motion capture devices 74D provided at least two of the thigh B1, shin B2, knee joint B3, sole B4, instep B5, and ankle B6 of the leg B11. The motion capture devices 74D detect the posture of the leg B11 as detection data α.

[0099] In this way, the sensors 74 (e.g., pressure sensor 74A, gyro sensor 74B, angle sensor 74C, motion capture 74D) detect the posture of body B (specifically, leg B11) as detection data α (e.g., pressure, inclination angle, bending angle, posture data) and supply the detection data α to the control unit 72.

[0100] The control unit 72 has, for example, a processor (CPU, GPU, etc.) and memory (RAM, ROM, etc.), and is fixed to the arm 18 (specifically, the second part 38 of the main body 26). The control unit 72 controls the actuator 114 to move the locking part 112 between the engagement position P1 and the disengagement position P2 based on the detection data α of the sensor 74. A method of controlling the actuator 114 executed by the control unit 72 will be described below.

[0101] The control unit 72 determines whether the leg B11 has moved to the front side of the slope or to the rear side of the slope based on the detection data α of the sensor 74. For example, the control unit 72 determines whether the leg B11 has moved to the front side of the slope or to the rear side of the slope based on the detection data α and the threshold value α th By comparing this threshold value α this determined in advance by a method such as an experiment or a simulation as a value corresponding to the detection data α detected by the sensor 74 when the leg B11 moves forward or backward on the slope.

[0102] When the control unit 72 determines that the leg B11 has moved forward on the slope, it operates the power unit 120 of the actuator 114 (specifically, applies a current from the power source 76 to the SMA 130b) to place the lock unit 112 in the disengagement position P2. As a result, when the leg B11 is extended forward on the slope as shown in FIG. 17, the assist force generating mechanism 100 generates an assist force Fa 12 The auxiliary device 10 generates the auxiliary force Fa 12 This assists the bending and stretching of leg B11 during walking.

[0103] On the other hand, when the control unit 72 determines that the leg B11 has moved to the rear of the slope (see the leg B12 in FIG. 17), it operates the power unit 120 of the actuator 114 to place the lock unit 112 in the engagement position P1. As a result, when the leg B11 is in the rear of the slope, the assist force generating mechanism 100 generates the assist force Fa 1 The auxiliary device 10 generates the auxiliary force Fa 1 In this way, the control unit 72 adjusts the assist force Fa according to the posture of the leg B11 walking on the slope (specifically, the degree of bending of the leg B11), 12 and auxiliary force Fa 1 The actuator 114 is controlled to switch between the above.

[0104] As described above, in this embodiment, the assistive device 70 includes the control unit 72 that controls the operation of the actuator 114 that drives the locking portion 112 between the engagement position P1 and the non-engagement position P2. According to this configuration, the assistive force Fa generated by the assistive force generating mechanism 100 is 12 and auxiliary force Fa 1 It can automatically switch between

[0105] In this embodiment, the assistive orthosis 70 further includes a sensor 74 that detects the posture of the body B (specifically, the leg L1). The control unit 72 controls the actuator 114 to move the locking unit 112 between the engagement position P1 and the disengagement position P2 based on the detection data α (e.g., data on pressure, tilt angle, bending angle, and posture) of the sensor 74.

[0106] According to this configuration, the assist force Fa generated by the assist force generation mechanism 100 is adjusted according to the walking state of the body B. 12 Or auxiliary force Fa 1 Specifically, as described above, when the leg B11 is in front of the slope (in other words, when the thigh B1 and the shin B2 of the leg B11 are deeply bent), a smaller assist force Fa 12 The assist force generating mechanism 100 generates a larger assist force Fa when the leg B11 is deeply bent. This allows the leg B11 to be flexibly supported. On the other hand, when the leg B11 is on the rear side of the slope (in other words, when the thigh B1 and the shin B2 of the leg B11 are extended), the assist force Fa 1 is generated by the assist force generating mechanism 100. This makes it possible to firmly support the leg B11.

[0107] In this embodiment, the function of the support orthosis 70 attached to the right leg B11 has been described, but it should be understood that two support orthosis 70 may be attached to the left leg B11 and the right leg B12, respectively. In this case, the mechanism 12 of the support orthosis 70 attached to the left leg B12 and the mechanism 12 of the support orthosis 70 attached to the right leg B11 may have a structure symmetrical to each other.

[0108] In addition, when the control unit 72 determines that the leg B11 has moved forward on the slope, it may operate the actuator 114 to place the locking portion 112 in the engagement position P1, whereas when it determines that the leg B11 has moved backward on the slope, it may operate the actuator 114 to place the locking portion 112 in the non-engagement position P2.

[0109] 18, even when the body B is walking across a slope, the control unit 72 may control the actuator 114 to move the locking unit 112 between the engagement position P1 and the disengagement position P2 based on the detection data α of the sensor 74. For example, the control unit 72 determines whether the right leg B11 is on the lower side or the upper side of the slope based on the detection data α.

[0110] In the case shown in Fig. 18, the right leg B11 is on the lower side of the slope. In this case, the control unit 72 of the assistive device 70A attached to the right leg B11 determines that the leg B11 is on the lower side of the slope based on the detection data α, and controls the actuator 114 to place the locking part 112 of the assistive device 70A in the engagement position P1. In this way, when the leg B11 is on the lower side of the slope, the assistive force generating mechanism 100 of the assistive device 70A generates an assistive force Fa by the action of the first biasing part 104. 1 The auxiliary device 70A generates the auxiliary force Fa 1 This assists the flexion and extension of leg B11 during walking.

[0111] On the other hand, when the control unit 72 of the assistive orthosis 70A determines that the leg B11 is on the upper side of the slope based on the detection data α, it controls the actuator 114 to place the locking unit 112 of the assistive orthosis 70A in the non-engagement position P2. In this way, when the leg B11 is on the upper side of the slope, the assistive force generating mechanism 100 of the assistive orthosis 70A generates the assistive force Fa by the action of the first biasing unit 104 and the second biasing unit 108. 12 The auxiliary device 70A generates the auxiliary force Fa 12 This assists the bending and stretching of leg B11 during walking.

[0112] When the leg B11 is on the lower side of the slope as shown in FIG. 18, the thigh B1 and the shin B2 of the leg B11 are in a relatively extended state. In this case, the assisting device 70A applies a larger assisting force Fa 1 The assist force generating mechanism 100 generates the assist force, which makes it possible to firmly support the leg B11 in the extended state.

[0113] On the other hand, when the leg B11 is on the upper side of the slope, the thigh B1 and the shin B2 of the leg B11 are bent relatively deeply. In this case, the assisting device 70A applies a smaller assisting force Fa 12 The assist force generating mechanism 100 generates the assist force, thereby enabling the bent leg B11 to be flexibly supported.

[0114] In addition, the control unit 72 of the support device 70B attached to the left leg B12 may also control the actuator 114 based on the detection data α of the sensor 74 so as to position the locking portion 112 in the engagement position P1 when the leg B12 is on the lower side of the slope, and to position the locking portion 112 in the non-engagement position P2 when the leg B12 is on the upper side of the slope as shown in Figure 18.

[0115] In the above embodiment, the control unit 72 and the power source 76 are fixed to the arm 18 (second portion 38). However, this is not limiting, and at least one of the control unit 72 and the power source 76 may be fixed to the arm 20 or the link portion 22, or may be held by the user without being fixed to the mechanism portion 12.

[0116] In the above-mentioned embodiment, the assistive orthosis 10 and 70 are attached to the thigh B1 and the shin B2 to assist in the flexion and extension movement of the thigh B1 and the shin B2. However, the present invention is not limited to this, and the assistive orthosis 10 or 70 may be attached to the forearm and upper arm of the human body B, for example, to assist in the flexion and extension movement of the forearm and upper arm. The present disclosure has been described above through the embodiments, but the above-mentioned embodiments do not limit the invention according to the claims. [Explanation of symbols]

[0117] 10,70,70A,70B Assistive devices 12 Mechanism 14,16 Wearing band 18,20 Arm 22 Link section 72 Control section 74 Sensors 100 Auxiliary force generation mechanism 104 First biasing portion 108 Second biasing portion 110 Slider 110a Slider body 110b Claw part 112 Rock Section 112a Ring section 112b Groove 114 Actuator 118 Rotating part 120 Power section 130a,130b Shape memory alloy (SMA)

Claims

1. An assist force generating mechanism for generating an assist force of an assist device that assists bending and stretching of a body, a first biasing portion and a second biasing portion arranged to be aligned with each other; a slider movably provided between the first biasing portion and the second biasing portion; a lock portion that is engaged with the slider and is movable between an engagement position at which the slider is prevented from moving relative to the second biasing portion and a non-engagement position at which the slider is released from the engagement and the slider is allowed to move, an auxiliary force generating mechanism that generates the auxiliary force by the action of the first biasing portion when the locking portion is disposed in the engaged position, and generates the auxiliary force by the action of the first biasing portion and the second biasing portion when the locking portion is disposed in the disengaged position.

2. The assist force generating mechanism according to claim 1 , further comprising an actuator that drives the locking portion between the engaged position and the disengaged position.

3. the lock portion is provided to be rotatable about a first axis parallel to a moving direction of the slider between the engagement position and the disengagement position, The actuator comprises: a rotation portion that is provided rotatably about a second axis perpendicular to the first axis and engages with the lock portion; The assist force generating mechanism according to claim 2 , further comprising: a power unit that rotates the rotation unit to rotate the lock unit between the engaged position and the disengaged position via the rotation unit.

4. 4. The assist force generating mechanism according to claim 3, wherein the power unit has a shape memory alloy connected to the rotating unit and expands and contracts in response to an electric current to rotate the rotating unit.

5. The slider has a slider body and a claw portion protruding outward from the slider body, The lock portion is a ring portion that surrounds the slider body and is rotatable between the engagement position and the disengagement position; and a groove portion that is formed in the ring portion so as to extend parallel to a moving direction of the slider, 2. The assist force generating mechanism according to claim 1, wherein when the ring portion is disposed in the engagement position, the claw portion engages with the ring portion to prohibit movement of the slider, whereas when the ring portion is disposed in the non-engagement position, the claw portion enters the groove portion to allow movement of the slider.

6. the first biasing portion includes a spring having a first spring constant; The assist force generating mechanism according to claim 1 , wherein the second biasing portion includes a spring having a second spring constant different from the first spring constant.

7. The assist force generating mechanism according to claim 1 , wherein the first biasing portion is capable of generating a biasing force greater than a biasing force generated by the second biasing portion.

8. An assistive device that assists in bending and stretching a first part and a second part of a body connected via a joint, a first arm attached to the first portion and a second arm attached to the second portion; a link portion that connects the first arm and the second arm to be bendable between an extended position and a bent position; 2. An assistive orthosis comprising: an assistive force generating mechanism according to claim 1, which applies an assistive force to the link portion to urge the first arm and the second arm from the bent position toward the extended position.

9. The prosthetic device of claim 8 , further comprising a controller that controls operation of an actuator that drives the locking portion between the engaged and disengaged positions.

10. Further comprising a sensor for detecting the posture of the body; The assistive device according to claim 9 , wherein the control unit controls the actuator to move the locking portion between the engaged position and the disengaged position based on detection data from the sensor.

Images