JP2015066215A - Motion-assisting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize an actuator of a motion-assisting device.SOLUTION: A motion-assisting device includes: joint parts 7A and 7B structured so as to turn in association with motion of the joint of a wearer; support frames 5a and 5b and turn frames 6a and 6b turnably connected to one another via the joint parts 7A and 7B; a coupling frame 9; an actuator 10 giving driving power to the turning motion of the joint parts 7A and 7B; and a twist spring 15 biasing the joint parts 7A and 7B so as to turn in a single direction.

Description

  The disclosed embodiment relates to a motion assisting device.

  Patent Document 1 discloses a lower limb wearing unit to be worn on a user's lower limb, a joint angle measuring unit for measuring a user's ankle joint angle, a pressure sensor provided on the sole of the lower limb wearing unit, and a lower limb wearing unit. An ankle joint electric appliance comprising an actuator provided at the ankle joint portion and a control unit for operating the actuator is described.

Japanese Patent Laid-Open No. 2005-000500

  When assisting joint movement with an actuator, the required torque may be different between the extension movement and the bottom bending movement. For example, when the ankle joint is operated with the foot floating in the air, the required torque increases because the dorsiflexion motion and the bottom flexion motion are motions in a direction against gravity. In addition, hemiplegic patients may be pulled in the direction in which the toes buckle due to a decrease in muscle strength of the dorsiflexor or plantar flexor muscles. Becomes larger.

  As described above, when the required torque differs between the joint extension operation and the plantar flexion operation due to the use environment of the device, the user's physical function, etc., it is necessary to select the actuator according to the required maximum torque. . For this reason, the above prior art may cause an increase in size of the actuator.

  The present invention has been made in view of such problems, and an object thereof is to provide an operation assisting device capable of downsizing an actuator.

  In order to solve the above-mentioned problem, according to one aspect of the present invention, there is provided an operation assisting device for assisting a motion of a joint of a wearer, wherein the joint is configured to rotate in accordance with the motion of the joint. A frame including: an actuator configured to apply a driving force to the pivoting operation of the joint portion; and a biasing member configured to bias the joint portion to pivot in one direction; Are applied.

  According to another aspect of the present invention, there is provided a motion assisting device that assists the motion of the joint of the wearer, the frame including a joint portion configured to rotate in accordance with the motion of the joint; A motion assisting device having means for applying a driving force to the pivoting operation of the joint and means for biasing the joint to pivot in one direction is applied.

  According to the present invention, the actuator of the motion assisting device can be reduced in size.

It is a perspective view which shows an example of the whole structure of the operation assistance apparatus which concerns on embodiment. It is the rear view which looked at the joint part of the movement auxiliary device from the back side. It is a right view which shows an example of a structure of the lower half part of a movement assistance apparatus. It is explanatory drawing showing rotation operation | movement of an ankle joint. It is a right view which shows an example of a structure of the lower half part of the operation assistance apparatus in the case of changing a spring control position according to rotation of a joint part using a gearwheel and a pin. It is the rear view which looked at the joint part of the right side of a movement assistance apparatus from the back side. It is explanatory drawing which shows the motion of the control position of the torsion spring by the pin at the time of rotation of the joint part in the dorsiflexion direction. It is a right view which shows an example of a structure of the lower half part of the operation assistance apparatus in the case of changing a spring control position according to rotation of a joint part using a gearwheel and a cam. It is the rear view which looked at the joint part of the right side of a movement assistance apparatus from the back side. It is explanatory drawing which shows the motion of the control position of the torsion spring by the cam at the time of rotation of the joint part in the dorsiflexion direction. It is a right view which shows an example of a structure of the lower half part of the operation | movement assistance apparatus at the time of setting a biasing member as a tension spring.

  Hereinafter, an embodiment will be described with reference to the drawings. The present embodiment is an example in which the motion assist device is applied to assist an ankle motion. In the following description, the front / rear / left / right directions are based on the front / rear / left / right directions of the wearer's body, and correspond to the directions indicated by arrows in the drawings.

<Configuration of motion assist device>
As shown in FIGS. 1 to 3, the motion assisting device 1 is a motion assisting device that assists the motion of the ankle joint of the wearer's left foot in this example. The movement assisting device 1 includes a shoe part 2 worn by the wearer on the left foot, and left and right sides of the shoe mouth 3 of the shoe part 2 attached to positions on the left side of the side face 4 (only the left side is shown in FIG. 1). One of the pair of support frames 5a and 5b, the pair of left and right joints 7A and 7B provided at the lower ends of the support frames 5a and 5b, and one of the joints 7A and 7B, in this example, outside the body of the wearer An actuator 10 disposed on the left joint 7A, and the torsion spring 15 provided on the other joint 7A, 7B, in this example, the right joint 7B on the inner side of the wearer's body. Prepare. The upper ends of the support frames 5 a and 5 b are connected by a connecting frame 9.

  The connecting frame 9 is a belt-like frame that is curved so as to swell rearward, and is provided at a height corresponding to the calf of the left foot of the wearer who has inserted the foot tip into the shoe portion 2. An annular band (not shown) attached around the wearer's shin is attached to the support frames 5a, 5b or the connecting frame 9. The support frames 5a and 5b have a shape in which a substantially upper half is bent upward in the rear side with respect to a substantially lower half in the vertical direction. The shapes of the support frames 5a and 5b and the connecting frame 9 shown in FIG. 1 are examples, and other shapes may be used.

  The joint portions 7A and 7B are configured to rotate in accordance with the movement of the wearer's ankle joint. As shown in FIG. 2, the left joint 7A connects the support frame 5a and the rotation frame 6a so as to freely rotate. The rotating frame 6 a has an upper end fixed to the drive shaft 11 of the actuator 10 and is provided so as to be rotatable with respect to the support frame 5 a via the drive shaft 11. The lower end of the rotating frame 6 a is fixed to the lower part of the left side surface 4 of the shoe part 2. The joint portion 7A is located on the left side of the ankle joint of the wearer's left foot.

  The right joint portion 7B connects the support frame portion 5b and the rotation frame 6b so as to freely rotate. The rotating frame 6b is fixed to a rotating shaft 14 whose upper end is rotatably supported by the lower end of the supporting frame 5b, and is provided so as to be rotatable with respect to the supporting frame 5b via the rotating shaft 14. . The pivot shaft 14 penetrates the lower end portion of the support frame 5b and protrudes outward. The lower end of the rotating frame 6 b is fixed to the lower part of the right side surface 4 of the shoe part 2. The joint portion 7B is located on the right side of the ankle joint of the wearer's left foot.

  The support frame portions 5a and 5b, the rotating frames 6a and 6b, and the connecting frame 9 correspond to an example of the frame.

  As shown in FIG. 2, the actuator 10 includes a speed reducer 12 fixed to the outer surface of the lower end portion of the support frame 5 a and a motor 13 attached to the speed reducer 12. The speed reducer 12 includes the drive shaft 11 connected to the output shaft of the motor 13. The drive shaft 11 is rotatably supported by the lower end portion of the support frame 5a, and is fixed to the rotating frame 6a through the support frame 5a.

  The actuator 10 rotates the drive shaft 11 via the speed reducer 12 by the motor 13. Thereby, the rotation frame 6a fixed to the drive shaft 11 rotates with respect to the support frame 5a, and the joint part 7A is driven. The driving force of the joint portion 7A by the actuator 10 is transmitted to the joint portion 7B via the shoe portion 2, and the rotation frame 6b rotates relative to the support frame 5a to drive the joint portion 7B. In this way, the actuator 10 gives a driving force to the rotating operation of the joint portions 7A and 7B. Driving of the joint portion 7 (7A, 7B) by the actuator 10 is performed in conjunction with the movement of the ankle joint. The actuator 10 corresponds to an example of a unit that applies a driving force to the rotation operation of the joint portion.

  As shown in FIGS. 2 and 3, the torsion spring 15 is installed with a rotating shaft 14 protruding outside the support frame 5 b around an intermediate portion 15 c. A first spring restricting pin 16a is provided at a position above the rotating shaft 14 on the outer surface of the support frame 5b, and a second spring restricting pin 16b is provided at a position below the rotating shaft 14 on the outer surface of the rotating frame 6b. ing. As described above, the torsion spring 15 has the intermediate portion 15c wound around the rotating shaft 14, the upper end portion 15a being in contact with the back surface of the first spring restricting pin 16a, and the lower end portion 15b being in contact with the second spring restricting pin 16b. It is in contact with the back. The upper and lower end portions 15a and 15b are engaged with the spring restricting pins 16a and 16b, respectively, by a pressing force generated between them. In the torsion spring 15, the upper and lower end portions 15 a and 15 b respectively press the spring regulating pins 16 a and 16 b forward, and the joint portion 7 B is rotated in the direction in which the lower end of the rotating frame 6 b rotates forward (corresponding to an example of one direction). ), That is, bias the ankle in the dorsiflexion direction. The urging force of the joint part 7B by the torsion spring 15 is transmitted to the joint part 7A via the shoe part 2, and the joint part 7A is urged in the dorsiflexion direction of the ankle joint. As a result, the shoe part 2 to which the lower ends of the rotating frames 6a and 6b are fixed is urged in the same direction as the left and right joint parts 7A and 7B, and the toes are placed against the ankle joint of the wearer wearing the shoe part 2. An assist force in the dorsiflexion direction that is raised upward can be applied. The torsion spring 15 corresponds to an example of an urging member and also corresponds to an example of means for urging the joint portion to rotate in one direction.

<Effect of embodiment>
As described above, the motion assisting device 1 of the present embodiment assists the motion of the wearer's joint by applying a driving force to the pivoting motion of the joint portion 7 by the actuator 10.

  Here, due to the usage environment of the motion assisting device 1, the body function of the wearer, and the like, the required torque may differ depending on the rotation direction of the joint portion 7. For example, as shown in FIG. 4 (a), when the left foot F is suspended in the air and the ankle joint A is operated, the joint motion in the dorsiflexion direction in which the foot tip B shown in FIG. Since the rotation is in the opposite direction, the necessary torque T becomes larger than the joint operation in the buckling direction in which the foot tip B shown in FIG. Further, for example, when the wearer is a hemiplegic person, the toe B may be pulled downward due to a decrease in muscle strength of the dorsiflexor muscles or strain of the plantar flexor muscles. Necessary torque T becomes larger than the bottom bending operation.

  In such a case, it is necessary to select the actuator 10 according to the required maximum torque. For example, in the above-described example, the torque T required for the back bending operation is larger than that required for the bottom bending operation. Therefore, the actuator 10 that can output the torque T necessary for the back bending operation is selected. As a result, the actuator 10 increases in size even though the torque required for the bottom bending operation is relatively small.

  Therefore, the motion assisting device 1 of the present embodiment biases the joint portion 7 in the dorsiflexion direction where the torque required by the torsion spring 15 is large. Thereby, the torque T required for the dorsiflexion operation can be reduced. Note that the torque T required for the bottom bending operation increases as compared with the case where no spring is provided because the urging force of the torsion spring 15 is applied in the opposite direction. However, the required maximum torque can be minimized by setting the urging force by the torsion spring 15 so that the torque T required for the back bending operation and the bottom bending operation becomes substantially the same. As a result, the actuator 10 can be reduced in size.

  In this embodiment, in particular, the torsion spring 15 is used as a biasing member that biases the joint portion 7. Thereby, compared with the case where other than a torsion spring is used, the installation space of an urging member can be reduced, and the enlargement of the operation assistance apparatus 1 can be suppressed.

  In this embodiment, in particular, the actuator 10 is disposed on the joint portion 7A located on one side (left side in this example) of the wearer's joint, and the torsion spring 15 is disposed on the other side (right side in this example). ). As described above, by disposing the torsion spring 15 and the actuator 10 on the opposite sides, interference between the installation spaces can be prevented, and the fit can be improved. Further, since the torsion spring 15 and the actuator 10 are arranged with good balance without being biased to one side, the appearance of the motion assisting device 1 can be improved.

  In the present embodiment, in particular, the actuator 10 is disposed at the joint portion 7A located on the outer side (the left side in this example) of the wearer's body. Thereby, it can avoid that the actuator 10 contacts the other leg | foot (right leg in this example).

<Modification>
The embodiment is not limited to the above contents, and various modifications can be made without departing from the spirit and technical idea of the embodiment. Hereinafter, such modifications will be described.

(1) When changing the spring restricting position according to the rotation of the joint using gears and pins In the above embodiment, the spring restricting pins 16a and 16b are fixedly installed on the support frame 5b and the rotating frame 6b. However, the second spring restricting pin 16b may be provided on the gear, and the restricting position of the torsion spring 15 may be changed according to the rotation of the joint portion 7B. An example of this modification is shown in FIGS.

  As shown in FIGS. 5 and 6, the right joint 7 </ b> B includes a rotation shaft 18 that is fixed to the inside (left side in FIG. 6) of the lower end of the support frame 5 b. The upper end of the rotating frame 6b is rotatably supported by the rotating shaft 18, and is rotatably connected to the support frame 5b. A first gear 20 having a shaft portion 20a coaxial with the rotating shaft 18 is fixedly installed on the outer side (right side in FIG. 6) of the lower end portion of the support frame 5b.

  Below the rotation shaft 18 on the outer surface of the rotation frame 6b, a second gear 22 (corresponding to an example of a rotation member and a gear member) that rotatably supports the shaft portion 22a is provided. The second gear 22 is meshed with the first gear 20, and when the rotating frame 6b rotates with respect to the support frame 5b, the second gear 22 revolves around the first gear 20 while rotating. That is, the second gear 22 rotates with respect to the rotation frame 6b according to the rotation operation of the joint portion 7B. A second spring restricting pin 16 b (corresponding to an example of a restricting member or a pin member) that restricts the position of the lower end portion 15 b of the torsion spring 15 in the rotational direction is provided on the outer peripheral portion of the outer surface of the second gear 22. The 1st spring control pin 16a is provided in the upper position of the 1st gearwheel 20 in the outer surface of support frame 5b like the above-mentioned embodiment.

  In the torsion spring 15, the intermediate portion 15c is wound around the shaft portion 20a of the first gear 20, the upper end portion 15a is brought into contact with the back surface of the first spring restriction pin 16a, and the lower end portion 15b is brought into contact with the second spring restriction pin 16b. It is in contact with the back. Then, the upper and lower end portions 15a and 15b of the torsion spring 15 press the spring restricting pins 16a and 16b forward by the pressing force, respectively, and urge the joint portions 7A and 7B in the dorsiflexion direction of the ankle joint.

  The movement of the restriction position of the torsion spring 15 when the joint portion 7B is rotated in the dorsiflexion direction will be described with reference to FIG. FIG. 7A shows a state in which the joint portion 7B is not rotated and the support frame 5b and the rotation frame 6b are in a straight line. The original position (angle) of the lower end portion 15b of the torsion spring 15 in this state is indicated by a virtual line L. From this state, as shown in FIG. 7 (b), when the rotating frame 6b rotates with respect to the support frame 5b and the joint portion 7B rotates in the dorsiflexion direction of the ankle joint, the second gear 22 becomes the shaft portion. Revolving around the shaft portion 20a of the first gear 20 in the counterclockwise direction while rotating in the counterclockwise direction around 22a (rotational axis thereof). The second spring restricting pin 16 b on the second gear 22 also revolves around the shaft portion 22 a (rotational axis thereof) of the second gear 22.

  Even if the joint portion 7B rotates in the dorsiflexion direction of the ankle joint as shown in FIGS. 7B and 7C due to the revolution of the second spring restriction pin 16b, the second spring restriction pin 16b. Can be held at substantially the same position as the virtual line L. As a result, even if the joint part 7 (7A, 7B) rotates, the opening angle of the torsion spring 15 can be maintained at substantially the same angle as in the initial state. Therefore, the urging force by the torsion spring 15 can be made almost constant regardless of the joint angle, and a situation in which the urging force of the torsion spring 15 is suddenly lost at the end of the rotation of the joint portion 7 can be prevented. it can. Further, since the position of the lower end portion 15b of the torsion spring 15 in the rotation direction can be changed according to the joint angle, for example, the biasing force is increased as the rotation of the joint portion 7 progresses. It becomes possible to set power more freely.

(2) When changing the spring restricting position according to the rotation of the joint using a gear and a cam In this modified example, a cam is provided instead of the second spring restricting pin 16b in the modified example (1). This is an example in which the restricting position of the torsion spring 15 is changed by the cam method in accordance with the rotation of the joint portion 7B. An example of this modification is shown in FIGS. 8 to 10, the same elements as those in FIGS. 5 to 7 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in FIGS. 8 and 9, a plate-like cam 24 (corresponding to an example of a regulating member and a cam member) having an elliptical shape is provided on the outer surface of the second gear 22 of the rotating frame 6b of the joint portion 7B. It has been. A shaft portion 22a serving as a rotating shaft of the cam 24 is rotatably supported by the rotating frame 6b. The torsion spring 15 has an intermediate portion 15 c hung on the shaft portion 20 a of the first gear 20 of the support frame 5 b, the upper end portion 15 a in contact with the back surface of the first spring regulating pin 16 a, and the lower end portion 15 b of the cam 24. It is in contact with the outer peripheral surface. Then, the upper and lower end portions 15a and 15b of the torsion spring 15 press the spring restricting pin 16a and the cam 24 forward by the pressing force, respectively, and urge the joint portions 7A and 7B in the dorsiflexion direction of the ankle joint.

  The movement of the restriction position of the torsion spring 15 by the cam 24 when the joint portion 7B is rotated in the dorsiflexion direction will be described with reference to FIG. FIG. 10A shows a state in which the right joint portion 7B is not rotated and the support frame 5b and the rotation frame 6b are in a straight line. The original position (angle) of the lower end portion 15b of the torsion spring 15 in this state is indicated by a virtual line L. From this state, as shown in FIG. 10 (b), when the rotating frame 6b rotates with respect to the support frame 5b and the joint portion 7B rotates in the dorsiflexion direction of the ankle joint, the second gear 22 becomes the shaft portion. Revolving around the shaft portion 20a of the first gear 20 in the counterclockwise direction while rotating in the counterclockwise direction around 22a (rotational axis thereof). The cam 24 on the second gear 22 also rotates around the shaft portion 22 a (rotational axis thereof) of the second gear 22.

  By the rotation of the cam 24, the position of the lower end portion 15b of the torsion spring 15 can be held at substantially the same position as the phantom line L as shown in FIGS. 10 (b) and 10 (c). Therefore, as in the modification (1), the urging force by the torsion spring 15 can be made almost constant regardless of the joint angle. In addition, since the position of the lower end portion 15b of the torsion spring 15 in the rotational direction can be changed according to the joint angle, the urging force by the torsion spring 15 can be set more freely.

(3) When the urging member is a tension spring In this modification, the tension spring 26 is used as shown in FIG. 11 to urge the joint portion 7 (7A, 7B) in the dorsiflexion direction. It is. An arm 25 extending forward is fixed to the rotating frame 6b of the joint portion 7B, and a tension spring 26 is attached between the arm 25 and the support frame 5b via stoppers 27a and 27b.

  The tension spring 26 pulls the arm 25 in the direction of the support frame 5b, whereby the joint portion 7B is rotated in the direction in which the lower end of the rotation frame 6b rotates forward (corresponding to an example of one direction), that is, the dorsiflexion of the ankle joint. Energize in the direction. The urging force of the joint part 7B by the tension spring 26 is transmitted to the joint part 7A via the shoe part 2, and the joint part 7A is urged in the dorsiflexion direction of the ankle joint. As a result, the shoe part 2 to which the lower ends of the rotating frames 6a and 6b are fixed is urged in the same direction as the joint parts 7A and 7B, and the toes are directed upward with respect to the ankle joint of the wearer wearing the shoe part 2. The assist force in the dorsiflexion direction can be applied. The tension spring 26 corresponds to an example of an urging member and also corresponds to an example of means for urging the joint portion to rotate in one direction. Also in this modification, the same effect as the above embodiment can be obtained.

(4) Others In the above, the case where the ankle joint is urged in the dorsiflexion direction has been described as an example. However, due to the use environment of the motion assisting device 1 and the body function of the wearer, the bottom flexion motion is more likely. When the required torque is larger than the dorsiflexion operation, the ankle joint may be urged in the bottom flexion direction. For example, in the above embodiment, the case where the ankle joint is operated with the foot floating in the air has been described. It is conceivable that the required torque becomes larger than the dorsiflexion operation. In such a case, by urging the ankle joint in the plantar flexion direction, the same effect as in the above embodiment can be obtained.

  In the above description, the case where the motion assisting device 1 assists the ankle joint motion of the left foot has been described as an example. However, the foot joint of the right foot may be used, or the foot joint of both feet may be applied. Further, although the actuator 10 and the torsion spring 15 (the tension spring 26) are separately arranged on the left and right support frames 5a and 5b, both may be arranged on one of the left and right, for example, the support frame 5a. Furthermore, the motion assisting device 1 can be applied not only to the ankle joint, but also to assist various joint motions of the human body such as the knee, wrist, elbow, shoulder, and crotch.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  In addition, although not illustrated one by one, the above-mentioned embodiment and each modification are implemented with various modifications within a range not departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 Operation assistance apparatus 2 Shoe part 5a, 5b Support frame (frame)
6a, 6b Rotating frame (frame)
7A, 7B Joint part 9 Connection frame (frame)
10 Actuator (Means to give driving force to the rotational movement of the joint)
11 drive shaft 15 torsion spring (biasing member, means for urging the joint to rotate in one direction)
16b Second spring regulating pin (regulating member, pin member)
22 Second gear (rotating member, gear member)
24 cam (regulating member, cam member)
26 Tension spring (biasing member, means for urging the joint to rotate in one direction)

Claims (9)

A motion assist device that assists the motion of the wearer's joint,
A frame including a joint portion configured to rotate in accordance with the movement of the joint;
An actuator configured to give a driving force to the rotation of the joint;
And a biasing member configured to bias the joint so as to rotate in one direction. The biasing member is
The motion assisting device according to claim 1, wherein the motion assisting device is a torsion spring provided at the joint. The frame is
The joints on both sides of the joint of the wearer;
The actuator is
Arranged on the joint located on one side of the joint of the wearer,
The torsion spring is
The motion assisting device according to claim 2, wherein the motion assisting device is disposed in the joint portion located on the other side of the joint of the wearer. The actuator is
The motion assisting device according to claim 3, wherein the motion assisting device is disposed at the joint located on the outer side of the body of the wearer. A regulating member that regulates the position of the end of the torsion spring in the rotational direction;
5. The rotating member according to claim 2, further comprising: a rotating member that includes the restricting member and is configured to rotate with respect to the frame in accordance with a rotating operation of the joint portion. A motion assisting device according to 1. The regulating member is a pin member;
The rotating member is
The motion assisting device according to claim 5, wherein the motion assisting device is a gear member configured to revolve the pin member around a rotation axis in accordance with a rotation operation of the joint portion. The regulating member is
A cam member having an elliptical shape,
The rotating member is
The operation assisting device according to claim 5, wherein the operation assisting device is a gear member configured to rotate the cam member around a rotation axis in accordance with a rotation operation of the joint portion. The frame is
Comprising the joint configured to rotate in accordance with the movement of the wearer's ankle joint;
The biasing member is
The motion assisting device according to claim 1, wherein the motion assisting device is configured to bias the joint portion so as to rotate in a dorsiflexion direction of the ankle joint. A motion assist device that assists the motion of the wearer's joint,
A frame including a joint portion configured to rotate in accordance with the movement of the joint;
Means for applying a driving force to the rotational movement of the joint part;
And a means for biasing the joint portion so as to rotate in one direction.

Images