WO2018168817A1 - Movement assisting device - Google Patents

Abstract

Provided is a movement assisting device (1) that assists a movement in which two sections that are connected by a joint change from a bent state to a stretched state, the movement assisting device (1) having: a rigid body (2) that is fixed to one of the sections; and an actuator (5) that is located in an angle opposite to an angle formed by the two sections in the bent state, and connected to the rigid body (2) by a connecting point (15) provided integrally with the rigid body (2), and moreover has one end fixed to the other section and is capable of reducing a distance between a fixed end (5e) and the connecting point (15).

Description

Operation assist device

The present invention relates to a motion assist device, and more particularly to a motion assist device that assists a motion from a bent state to an extended state.

As shown in Patent Document 1, an apparatus has been proposed in which an assist device is attached to a person's leg to assist the bending and stretching operation of the leg. The assist device connects each link piece fixed corresponding to the thigh and lower leg of a human leg via a rotation mechanism at a position corresponding to the knee joint of the leg, By rotating the mechanism with a drive source such as a motor, the legs are forcibly bent and extended halfway. According to the assist device, since the driving force of a motor or the like is transmitted to the leg portion via each link piece configured as a rotatable link, for example, the assist for bringing the bent leg portion into an extended state You can gain power.

However, in the assist device described above, each link piece is formed as a rigid body and is configured to integrally restrain the thigh and lower leg, so that the operation of opening the leg in the shoulder width direction or the leg The movements inherent to the legs, such as the twisting movement, are limited, and the degree of freedom of movement is low.
In addition, the trajectory drawn by the knee joint when the leg is bent and extended is not constant, and varies depending on individual differences or body posture. However, in the above assist device, the locus drawn by the rotation mechanism is constant, and the position is always in a corresponding relationship with the knee joint. Smooth operation is hindered, and as a result, it becomes a factor that hinders wearing comfort that should be required as an assist device.

The present invention has been made in view of the above-described problems, and provides an assist device capable of improving the degree of freedom of movement and wearability while ensuring the assist force during the extension operation of the leg.

As a configuration for solving the above problem, an operation assist device that assists an operation when two parts connected by a joint are changed from a bent state to an extended state, and a member fixed to one part; And an actuator having a fixed end connected to the member via a connecting portion provided integrally with the member and fixed to the other portion, and the connecting portion has an angle formed by the two portions in the bent state. Located in the diagonal, the actuator is configured to be able to shorten the distance between the fixed end and the connecting portion.
According to this configuration, when the actuator is contracted, a moment acts on the member in a direction in which the two portions are extended with the connection portion (connection point) between the member and the actuator as a force point. By changing the distance from the connecting portion of the member, it is possible to obtain an assist force when extending from the bent state. Further, since the relative relationship between the two parts and the motion assisting device is not fixed, the sense of restraint during assisting can be reduced.

As another configuration for solving the above-described problem, there is provided an operation assist device that assists an operation when a thigh and a lower leg connected by a knee joint change from a bent state to an extended state. The member fixed to the thigh, the distance changing means fixed to the member, and located within the diagonal of the angle formed by the thigh and the crus, and provided integrally with the member A wire guide and a wire fixed to the crus and spanned over the distance varying means via the wire guide are provided.
According to this configuration, by shortening the distance varying means, the moment acts on the member in the direction in which the two parts are extended with the wire guide serving as the connecting portion between the member and the wire as the force point, so the wire is fixed. By changing the distance between the end and the wire guide, it is possible to obtain an assist force when extending from the bent state. Further, since the relative relationship between the two parts and the motion assisting device is not fixed, the sense of restraint during assisting can be reduced.
As the distance changing means, a member whose total length is variable, in other words, a member whose distance between both ends is variable can be used. A stretchable body can be exemplified as a specific example of the distance changing means.

Further, as another desirable configuration, the actuator includes a rubber or a wire.
According to this configuration, by using a non-rigid member as the actuator, the constraint between the two parts can be further reduced, which is also effective when performing a torsional motion at the joint.

Further, as another desirable configuration, the actuator includes a wire, and the motion assist device includes a length adjustment mechanism that can adjust the length of the wire in the variation of the two portions to the extended state or the bent state. .
According to this structure, the slack of the wire at the time of extension and bending can be prevented.

As another desirable configuration, the length adjusting mechanism includes a tensioner that applies tension to the wire.
According to this configuration, it is possible to always apply tension to the wire, thereby preventing the wire from sagging.

Further, as another desirable configuration, the actuator includes a distance varying means and a wire, and the wire is stretched over the pulley mechanism.
As the distance changing means, a member whose total length is variable, in other words, a member whose distance between both ends is variable can be used. A stretchable body can be exemplified as a specific example of the distance changing means.
As another configuration, the actuator includes a distance varying means having a variable overall length, and a wire connected to the distance varying means. Between the distance varying means and the connecting portion, the distance varying means, and the fixed end. It is good also as a structure by which a pulley mechanism is provided between these and a wire is spanned over the pulley mechanism.
According to these configurations, the expansion / contraction amount of the entire actuator can be increased with respect to the change amount of the distance changing means.
As a pulley mechanism, a mechanism for converting the amount of movement of the wire from the total amount of fluctuation of the distance variation means, more specifically, the amount of movement of the wire is increased (for example, twice the total amount of variation of the distance variation means). ) Or a reduction (eg, halved) mechanism can be employed. Specific examples of the pulley mechanism include a pulley (pulley) constituting the connecting portion, a pulley (pulley) constituting the fixed end, a pulley (pulley) supported by the device or part of the device, supported by the member, or a member. A pulley (pulley) that forms a part of the pulley, and a pulley that is supported by the distance varying means or that forms a part of the distance varying means can be exemplified.

As another desirable configuration, an extension distance adjusting means for adjusting an extension distance per unit time between the fixed end and the connecting portion when the two portions change from the extended state to the bent state; and did.
As the extension distance adjusting means, means for adjusting the full length change speed of the distance changing means (expandable body) or means for regulating the full length changing speed of the distance changing means (extensible body) can be adopted.
According to this configuration, it is possible to assist the operation of squatting from the extended state to the bent state.

Further, as another desirable configuration, the other part includes a first part, a second part, and a joint connecting the first part and the second part, and the fixed end of the actuator Was fixed to the first part or the second part.
Here, one part can be a thigh, the first part of the other part can be a crus, and the second part of the other part can be a foot.
According to this configuration, it is possible to assist more efficiently.
In this configuration, the fixed end of the actuator is positioned within the diagonal of the angle formed by the first part (for example, the axial direction p2 of the lower leg) and the second part (for example, the axial direction p4 of the foot) in the bent state. It is preferable to do. In this case, an assist force for extending the first part and the second part from the bent state can also be obtained.

Further, as another desirable configuration, the motion assist device is configured to assist the motion when the thigh and the lower leg connected by the knee joint change from the bent state to the extended state.
According to this configuration, it is possible to assist the start-up operation when the user starts up from a squatting state with a large load.

Further, as another desirable configuration, a connection portion between the member and the actuator is disposed on the side portion of the knee joint.
According to this configuration, the extension movement of the joint is not hindered.

Further, as another desirable configuration, the distance varying means is disposed on the thigh side.
According to this configuration, since the inertial force is reduced, it is possible to easily walk while wearing the motion assist device.

As another desirable configuration, the actuator includes a distance varying means located on the thigh side and a wire located on the crus side and connected to the distance varying means.
According to this configuration, since the inertial force is reduced, it is possible to easily walk while wearing the motion assist device.

As another desirable configuration, the distance varying means is disposed on the thigh side and the crus side.
According to this configuration, the assist force can be further increased.

As another desirable configuration, the actuator includes a first distance varying means located on the thigh side, a second distance varying means located on the crus side, and two distance varying means. And a wire to be configured.
According to this configuration, the assist force can be further increased.

It is a lineblock diagram of the operation assistant device concerning this embodiment. It is a figure which shows the mounting state of an operation assistance apparatus. It is a figure which shows the mounting state of the operation assistance apparatus of FIG. 2A in a bending state. It is a block diagram of an actuator. It is a block diagram of an actuator. It is a block diagram of an artificial muscle. It is a block diagram of an artificial muscle. It is a schematic diagram which shows a rising operation. It is a schematic diagram which shows a rising operation. It is a schematic diagram which shows a rising operation. It is a schematic diagram which shows a rising operation. It is a schematic diagram which shows a rising operation. It is a schematic diagram which shows a rising operation. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a figure of other embodiment of an operation | movement assistance apparatus. It is a block diagram of a length adjustment mechanism. It is a block diagram of a length adjustment mechanism. It is a block diagram of a length adjustment mechanism.

The motion assist device 1 shown in FIGS. 1, 2A, and 2B is, for example, a device that assists a rising motion when a person lifts a load. In the following embodiments, an example in which the motion assist device 1 is applied to a leg portion of a human body is shown. However, the motion assist device 1 has a bent state such as an arm portion centered on an elbow joint and a waist portion centered on a lumbar spine. The present invention can be applied to any part as long as it can take the extended state. Further, the application of the motion assist device 1 is not limited to a human body, and can be applied to other mechanical structures and the like as long as two parts that can be connected to each other through joints and can take a bent state and an extended state are provided.

As shown in each figure, the motion assist device 1 includes a thigh brace 2 attached to a thigh as one part of two parts connected via a knee joint, and a crus part as the other part. A lower leg brace 4 to be attached and an actuator 5 for applying a driving force to the upper leg brace 2 and the lower leg brace 4 are provided. That is, the motion assist device 1 regards the femur in the thigh and the crus in the lower leg as a pair of nodes (links), and regards the knee joint that rotatably connects these nodes as one link mechanism, Assists (assist) the movement of the legs when the knee is bent and extended, especially when moving from the bent state to the extended state.

The thigh orthosis 2 and the lower thigh orthosis 4 are respectively a mechanism attaching member 2A; 4A for attaching the actuator 5, and a fixing belt 2B; 4B for fixing the mechanism attaching member 2A; 4A to the thigh and the lower thigh, Is provided. In addition, the cushioning material etc. which are not shown in figure are provided in the back surface of mechanism attachment member 2A; 4A, and a buffer with a human body is aimed at. The mechanism attachment member 2A; 4A is made of, for example, a hard resin having flexibility. For example, a hook-and-loop fastener made of a non-stretchable belt and functioning as a fixing means is applied to the fixing belt 2B; 4B.

The mechanism attachment member 2A is formed, for example, with a curve along the outer periphery of the thigh, and is fixed to the thigh by the fixing belt 2B. For example, the mechanism attachment member 2A will be described as being mounted so as to be wound from the front part of the thigh to the rear part through the outer side part.
The mechanism attachment member 2 </ b> A includes a thigh side fixing portion 11 that can fix one end side of an actuator 5 to be described later, and a protruding portion 13.

The protrusion 13 is formed, for example, as a part of the rod-like member 17 fixed to the mechanism attachment member 2A, and in a posture in which the thigh orthosis 2 is attached to the thigh and crouched (when the knee joint is bent), the knee joint It extends so as to protrude a predetermined length forward. The rod-like member 17 is fixed integrally with the mechanism attachment member 2A along the outer side portion of the thigh so as to form an exoskeleton in the thigh. As shown in FIG. 2B, the rod-like member 17 has a length over the entire thigh as the tip 17A projects forward from the knee joint. The material of the rod-shaped member 17 may be any material that has little bending deformation in the assist operation. Considering that the rod member 17 is attached to the human body, it is lightweight and lightweight such as aluminum having rigidity that does not lose the force during the assist operation. Pipes such as non-ferrous metal and fiber reinforced resin can be applied. That is, the rod-shaped member 17 only needs to have a rigidity that can be regarded as a rigid body that resists the force during the assist operation.

A wire guide (connecting portion) 15 for guiding a wire 8 that constitutes a part of the actuator 5 described later is provided on the tip end of the protrusion 13 (tip 17A of the rod-like member 17). That is, the wire guide (connecting portion) 15 is provided integrally with the protruding portion 13 (bar-shaped member 17), in other words, maintained at a certain relative position with the protruding portion 13 (bar-shaped member 17). As shown in FIG. 2B, a wire fixing portion 15 </ b> A for fixing the end portion of the wire 8 is provided on the rotating shaft portion of the wire guide (connection portion) 15. As shown in FIG. 2B, the wire guide 15 has an angle formed by an extension line p1 of the thigh (femur) and an extension line p2 of the crus (crus tibia) in a squatting posture (when the knee joint is bent). It is set so as to be located within the diagonal φ ′ of φ. In other words, the length of the rod-shaped member 17 is set so that the wire guide 15 is located within the diagonal of the angle formed by the two parts of the thigh and the lower leg connected by the knee joint.

The wire guide 15 may be any member that regulates the moving direction of the wire 8 pulled by the elastic body 9 to be described later, such as a pulley, a pin, or a groove and that does not hinder the movement. The wire guide 15 extends the wire 8. The direction is changed. In the example shown in FIGS. 1 to 5F, a pulley is used as the wire guide (connection portion) 15. In this case, the rotation shaft of the pulley is provided on the rod-shaped member 17 so as to be parallel to the rotation axis C of the knee joint.

The mechanism attachment member 4A is formed so as to be attachable along the side of the lower leg, and is fixed to the ankle side by the fixing belt 4B. The mechanism attachment member 4A is provided with a crus side fixing portion 16 capable of fixing the other end side of the actuator 5. An end 5e of the wire 8 constituting the actuator 5, that is, the fixed end 5e of the actuator 5 in the illustrated example is fixed to the crus fixing portion 16. The crus side fixing part 16 is constituted by, for example, a plate-like member 12 and is screwed to the mechanism mounting member 4A so that the end portion (fixed end of the actuator 5) 5e of the wire 8 is connected to the mechanism mounting member 4A. Secure with.

The actuator 5 is connected to the rod-like member 17 (projection 13) through a connection part provided integrally with one part (thigh), and is fixed to the other part (crus). It has a fixed end 5e. The actuator 5 can shorten the distance between the fixed end 5e and the connecting portion, and outputs an assist force that assists the operation of the two parts by shortening the distance. In the example shown in FIGS. 1 to 5F, the connecting portion is constituted by a wire guide 15. The wire 8 of the actuator 5 is stretched over the wire guide 15, and is thereby connected to the rod-shaped member 17 (projecting portion 13) via the wire guide (connecting portion) 15. In the example shown in FIGS. 1 to 5F, the fixed end 5e is constituted by the end portion of the wire 8 which is opposite to the side connected to the stretchable body 9.

The actuator 5 shown in FIGS. 1 to 5F is roughly configured to include a telescopic body 9 and a wire 8, and the telescopic body 9 functions as a distance varying means for varying the entire length of the actuator 5. The stretchable body 9 can vary its entire length. In other words, the stretchable body 9 can vary the length between its both ends. As shown in FIGS. 3A and 3B, the stretchable body 9 includes a plurality of (two in the present embodiment) axial fiber-reinforced artificial muscles (hereinafter simply referred to as artificial muscles) 18 that expand and contract in the axial direction by the supply of fluid. 18 is comprised. As shown in FIGS. 4A and 4B, the artificial muscle 18 has a configuration in which a carbon fiber sheet 22 is inserted into a cylindrical body 19 made of, for example, natural latex rubber. In the carbon fiber sheet 22, a plurality of carbon fibers 21 are oriented along the axial direction of the cylindrical body 19, and restrains the extension of the cylindrical body 19 in the axial direction. Both ends of the cylindrical body 19 are closed by terminal members 23A and 23B. Thereby, an air chamber 26 is formed on the inner peripheral side of the cylindrical body 19. One terminal member 23 </ b> A is connected to a tube 45, which will be described later, and is provided with an air inlet 25 communicating with the air chamber 26. A plurality of rings 24 are provided on the outer periphery of the cylindrical body 19 at equal intervals in the axial direction. When air as an example of a fluid is supplied into the air chamber 26 of the artificial muscle 18 having the above-described configuration, the cylindrical body 19 expands in the radial direction so as to have a plurality of lumps partitioned by the ring 24, and carbon. The fiber sheet 22 is contracted in the axial direction by the restraining force of the fiber sheet 22. Further, the air in the air chamber 26 is exhausted to return to its natural length (extend). By using the artificial muscle 18 having such a configuration, the extension / contraction body 9 can be reduced in weight, and the assist force can be changed according to the rising motion. The artificial muscle 18 has a characteristic that an output characteristic (traction force) with respect to a contraction stroke is large at the initial stage of contraction and gradually decreases toward the end of contraction. This characteristic corresponds to the human characteristic that a large force is required at the initial stage of a person's rising motion, and the required force gradually decreases with the progress of the rising motion. It is preferable as a power source. The artificial muscle 18 is not limited to the above-described one, and may be another McKibben type artificial muscle or the like.

3A and 3B, the stretchable body 9 is arranged in parallel so that the stretchable axes of the pair of artificial muscles 18; 18 are parallel to each other. The respective ends of the artificial muscles 18; 18 are connected to each other by an upper connecting member 30 and a lower connecting member 31 to be integrally formed. The upper connecting member 30 is made of, for example, a metal flat plate member, and the artificial muscles 18; 18 are positioned at regular intervals by fixing the terminal members 23A of the artificial muscles 18; 18 by fixing means such as bolts. The Further, the upper connecting member 30 is provided with an L-shaped connecting portion 32 connected to the thigh orthosis 2. One of the connection portions 32 is fixed to the upper coupling member 30, and the other is connected to the thigh brace 2 through the through hole 33.

The lower connecting member 31 is made of, for example, a metal angle member, and the artificial muscles 18; 18 are positioned at regular intervals by fixing the terminal members 23B of the artificial muscles 18; 18 by fixing means such as bolts. Is done. In addition, a wire guide 14 to which the other end side (the other end side portion) of the wire 8 is connected is provided at the center portion of the lower connection member 31. The wire guide 14 may be any member that restricts the moving direction of the wire 8 pulled by the elastic body 9 described later, such as a pulley, a pin, or a groove, and does not hinder the movement. Is converted. That is, the wire 8 is stretched over the wire guide 14 and is connected to the stretchable body (distance varying means) 9 via the wire guide 14. In the illustrated example, a pulley is used as the wire guide 14. In this case, the rotation shaft of the pulley may be provided so as to be orthogonal to the lower connecting member 31.

The stretchable body 9 having the above-described configuration is screwed to the thigh-side fixing portion 11 provided in the thigh brace 2 through a through-hole 33 (see FIG. 3A) formed in the connection portion 32 of the upper coupling member 30 (see FIG. 2A and 2B), and is attached to the thigh orthosis 2 so as to be rotatable. In the present embodiment, the thigh side fixing portion 11 is provided on the rod-shaped member 17. Attachment of the expansion / contraction body 9 to the thigh side fixing portion 11 is not limited to screwing, and may be freely rotatable by inserting a pin or the like.

Next, the path of the wire 8 will be described with reference to FIGS. 2A and 2B. As described above, the wire 8 extends via the stretchable body 9 and the wire guide 15 connected to the thigh orthosis 2. More specifically, when viewed from the lower leg brace 4 side, the wire 8 has one end forming the fixed end 5e of the actuator 5 fixed to the lower leg side fixing portion 16 of the lower leg brace 4 and is attached to the distal end 17A of the rod-like member 17. It extends over the wire guide 14 of the extendable body 9 via the provided wire guide 15, changes the extension direction, and extends toward the wire guide 15. That is, the wire 8 is stretched over the wire guide 14 and is connected to the stretchable body (distance varying means) 9 via the wire guide 14. The other end of the wire 8 reaching the wire guide 15 is fixed to a wire fixing portion 15 </ b> A provided in the wire guide 15.
The wire 8 having such a path is not limited to a metal and may be a synthetic fiber obtained by twisting organic fibers. Further, the wire 8 is preferably made of a material having a low stretchability when tension is applied. In view of durability, metallic or non-metallic inorganic fibers are preferable, and from the viewpoint of weight, synthetic fibers obtained by twisting organic fibers are preferable.

The length of the wire 8 is adjusted so that there is no play when, for example, the knee joint is in the maximum bending state. The case where the bending state is maximum means an angle when the intersection angle (joint angle) φ between the extension line p1 of the thigh and the extension line p2 of the crus becomes minimum as shown in FIG. 2B. For example, the joint angle between the femur and the crus (tibia) when the knee is bent to the maximum. That is, the joint angle φ is also an inclination angle of the thigh with respect to the crus, for example.

The expansion / contraction body 9 is controlled by the driving device 40. The driving device 40 includes an air supply unit 41 that supplies compressed air to the artificial muscle 18 that constitutes the expansion body 9, a control valve 42 that controls the pressure of the compressed air, and a compression that is supplied from the air supply unit 41 to the artificial muscle 18. And a control unit 43 for controlling air. The air supply means 41 is constituted by, for example, an air compressor or an air tank.

The control valve 42 adjusts the flow rate of air supplied to the artificial muscle 18. For example, a proportional solenoid valve is applied to the control valve 42. The proportional solenoid valve adjusts the flow rate of air when the compressed air accumulated in the air supply means 41 is supplied to the artificial muscle 18 based on a signal output from the control unit 43. The proportional solenoid valve is a normally closed type that shuts off the supply of air to the artificial muscle 18 when no signal is input. The control valve 42 is connected to the air supply means 41 and the tube 44, and is connected to the artificial muscle 18 and the tube 45. The tube 44 and the tube 45 preferably have pressure resistance and flexibility.

Further, for example, a branch pipe 46 is provided in the middle of the tube 45 connecting the control valve 42 and the artificial muscle 18, and an exhaust valve 47 for exhausting the air supplied to the artificial muscle 18 is provided. The exhaust valve 47 opens and closes the exhaust valve 47 based on a signal output from the control unit 43 to exhaust the air supplied to the air chamber 26 of the artificial muscle 18.

The control unit 43 temporarily stores a CPU as a calculation means, a ROM for storing a program and parameters for controlling assist force, and input values and calculation results from the motion detection sensor 50 and the load detection sensor 51. A microcomputer including storage means such as a RAM and a ROM, and an I / O that can be connected to the outside are provided. The control unit 43 controls signals output to the control valve 42 and the exhaust valve 47 in accordance with output values output from the motion detection sensor 50 and the load detection sensor 51. For example, the control unit 43 stores, in advance, data in which the correspondence relationship between the load value and the pressure of the air supplied to the air chamber 26, a pressure calculation formula, and the like are stored in the storage unit. Based on the load value and the operation value detected by 51, the signal output to the control valve 42 and the exhaust valve 47 is controlled.

The motion detection sensor 50 is a sensor for detecting a motion of a human body, and detects a motion (rising motion) that rises from a state where a person is squatting. For example, a change in the tension of the wire 8 or an acceleration sensor can be used. The load detection sensor 51 is a sensor for setting an assist force in the rising motion, and detects, for example, a load value related to the sole. For example, a pressure sensor or the like can be used as the load detection sensor 51.

The motion detection value detected by the motion detection sensor 50 and the load value detected by the load detection sensor 51 are output to the control unit 43, respectively. In the control unit 43, the flow rate of air supplied to the artificial muscle 18, that is, the pressure, is calculated based on the input detection value and load value.

A method for mounting the motion assist device 1 on a human body will be described. In the following description, it is assumed that the change in the overall length of the actuator 5 when the expandable body 9 contracts from the extended state allows the operation from the bent state to the extended state.
First, the thigh brace 2 and the lower leg brace 4 are attached to each part of the leg. Next, tension adjustment of the wire 8 is performed in the crus side fixing part 16 in the crus side in a squatting posture so that the bent state of the knee is maximized. In this embodiment, since the artificial muscle 18 configured by a flexible member is applied to the artificial muscle 18, the tension of the wire 8 is adjusted so that play is zero, thereby assisting by the actuator 5. You can get power without delay.

FIGS. 5A to 5F are diagrams showing an assist state by the motion assist device 1. FIG. 5A to 5C are schematic diagrams showing the motion assist device 1 including a human posture. 5D to 5D are schematic views showing the operating state of the actuator 5. 5D is the same state as FIG. 5A, FIG. 5E is the same state as FIG. 5B, and FIG. 5F is the same state as FIG. 5C. Hereinafter, the operation of the motion assist device 1 will be described.

As shown in FIG. 5A and FIG. D, for example, when squatting to lift a load placed on the floor and holding the load in the hand, the load detection sensor 51 arranged on the sole of the foot causes the weight of the load and the weight of the person. Is output to the control unit 43 as a load value. Next, a signal is output to the control unit 43 when the motion detection sensor 50 detects an operation of trying to get up from a state of squatting by a person's intention from a state of holding a load. The control unit 43 compares the input load value with the rising motion map and determines a signal to be output to the control valve 42 so as to obtain a predetermined assist force. In this case, a signal is output only to the control valve 42, and the exhaust valve 47 remains closed.

As shown in FIGS. 5B, 5C, 5E, and 5F, the artificial muscle 18 contracts in the axial direction by the supply of air by the operation of the control valve 42, and the wire 8 is pulled. When the wire 8 is pulled, the tension of the wire 8 acts on the wire guide (connection portion) 15. That is, the wire guide (connection part) 15 is a point of action of force due to contraction of the artificial muscle 18, in other words, functions as a point of connection of force. Then, as the wire 8 is pulled, a rotational moment F (arrow in FIG. 5E) with the wire guide (connection portion) 15 serving as a force connection point as a fulcrum is generated in the thigh orthosis 2 from the bent state in the leg portion. Sufficient assisting force can be obtained to stand up to the extended state.

That is, as shown in FIGS. 5A and 5B, in a crouched state, the stretchable body 9 contracts and pulls on the wire 8, so that the wire guide (connection portion) 15 becomes the crus side fixing portion 16 (fixing the actuator 5. Since it is pulled toward the end 5e), a rotational moment F (see FIG. 5E) acts on the other end side of the rod-like member 17 in a direction aligned with the extension connecting the crus side fixing portion 16 and the wire guide 15. . Thereby, the rotational force centering on the rotational axis C of the knee joint acts on the thigh, and the assist force to the extended state acts.

5B, FIG. 5C, FIG. 5E, and FIG. 5F, in the process of reaching the extended state, the position of the wire guide (connection portion) 15, that is, the connection point of the force is the extension line p1 of the thigh. Is maintained within the diagonal φ ′ of the angle φ formed by the extension line p2 of the lower leg and the thigh where the rod-like member 17 is attached continuously obtains the assist force necessary for rising. Will be.

In particular, in the knee joint where the thigh and crus are connected, the position of the rotation axis C moves in the process of moving from the bent state to the extended state, and therefore the rotation axis C of the knee joint and the wire guide (connection) Part) 15 is set so that the position of the wire guide 15 is maintained within the diagonal φ ′ of the angle φ formed by the extension line p1 of the thigh and the extension line p2 of the crus so that the position of the part 15 does not overlap. By doing so, a sense of incongruity during the assist operation can be eliminated.
That is, by contracting the expansion and contraction body 9, the connection point (wire guide 15) between the rod-shaped member 17 and the actuator 5 is used as a power point, and the two parts of the lower leg and the thigh are stretched in a bar-like direction. A moment is applied to the member 17. The distance between one end of the wire 8 fixed to the lower leg brace 4 (fixed end 5e of the actuator 5) and the wire guide 15 (connecting portion) of the rod-like member 17 can be changed. Since the relative relationship between the two parts of the part and the thigh brace 2 and the lower leg brace 4 is not fixed, the sense of restraint can be reduced.

Further, in the motion assist device 1 according to the present example, since the relatively heavy elastic body 9 is provided on the thigh side, the heavy object is close to the position of the center of gravity of the human body, and the weight feeling when worn Can be reduced. That is, it is possible to reduce a sense of discomfort during other operations such as walking when the motion assist device 1 is not operating.

Further, by using a flexible non-stretchable member such as the wire 8 as a part of the actuator 5, the restriction between the two parts of the thigh and the crus can be further reduced.
Moreover, since the wire 8 has flexibility, it can assist also suitably about the operation | movement with a torsional motion which stands | starts up in the state which opened the knee by arbitrary width.

In the above-described embodiment, the operation assist from the bent state to the extended state has been described. However, the operation assist from the extended state to the bent state can also be performed.
For example, when operating from the extended state to the bent state, the artificial muscle 18 is most contracted in the axial direction in the extended state, and the control unit 43 controls the speed at which air is discharged from the exhaust valve 47. It is possible to assist the squatting action when squatting from a standing state. That is, an extension distance adjusting means for adjusting the extension distance per unit time when the control unit 43 extends the entire length of the actuator 5 by controlling the speed at which the control unit 43 discharges air from the exhaust valve 47. Can function as.

Further, in the motion assist device 1 according to this example, by applying a pulley to the wire guide 14 of the telescopic body 9, the wire guide 14 acts as a pulley mechanism, and the traction amount is twice the contraction amount of the telescopic body 9. Since the wire 8 is pulled, an actuator having a small stroke amount can be employed even in a portion where the change in the joint angle from bending to extension of the knee joint or the like is large.
In this example, the fixed end of the wire 8 is set on the knee joint side, that is, on the thigh brace 2. However, the position is not limited to this as long as the path of the wire 8 can be reversed. A part different from each appliance may be set as a fixed end.

Hereinafter, another embodiment of the motion assist device 1 will be described with reference to FIGS. 6A to 6C. FIG. 6A shows an example in which the position of the stretchable body 9 is changed from the thigh side to the crus side. In this example, the stretchable body 9 is connected to the lower leg orthosis 4 and one end of the wire 8 is fixed to a wire fixing portion 14A formed on the rotation center axis of the wire guide 14 provided on the stretchable body 9, The other end extends toward the wire guide 14 via the wire guide 15 of the thigh orthosis 2, and is fixed to the wire fixing portion 15 </ b> A provided on the wire guide 15 of the thigh orthosis 2 via the wire guide 14. ing.

In the example shown in FIG. 6A, the connection portion provided integrally with one portion (thigh) is constituted by a wire guide 15. That is, the wire guide 15 is held at a certain relative position with respect to one part (thigh). In this example, the actuator 5 is connected via a wire guide (connecting portion) 15 to a rod-like member 17 (projecting portion 13) fixed to one portion (thigh). The fixed end 5 e of the actuator 5 is fixed to the other part (crus) in the crus fixing part 16. The actuator 5 has a telescopic body (distance varying means) 9 located on the other part (crus) side and a wire 8 located on the one part (thigh) side and connected to the telescopic body 9. is doing. The actuator 5 is connected to the connection portion 15 by the wire 8 being stretched over the wire guide 15. The fixed end 5e of the actuator 5 is configured by a connection portion 32 (see FIG. 3A) that is connected to the stretchable body 9 and fixed to the lower leg brace 4. The connection portion 32 is fixed to the mechanism attachment member 4 </ b> A of the crus orthosis 4 by a fastener such as a bolt that penetrates the through hole 33.

FIG. 6B shows an example in which the stretchable body 9 is provided in each of the thigh and crus. That is, the actuator 5 includes a first distance varying means 9B located on the thigh side, a second distance varying means 9A located on the crus side, a wire 8 connecting the two distance varying means, have. In this example, the expansion / contraction body 9A constituting the second distance variation means is connected to the crus 4 and the expansion body 9B constituting the first distance variation means is connected to the thigh brace 2, and one end of the wire 8 is connected to the expansion / contraction body 9A. While being fixed to the provided wire fixing portion 14A, the other end side is connected to the wire fixing portion 14B provided to the stretchable body 9B via the wire guide 15 of the thigh orthosis 2. Thus, the assist force can be increased by providing the stretchable bodies 9A and 9B on each of the two parts.

In the example shown in FIG. 6B, the connection portion provided integrally with one portion (thigh) is constituted by the wire guide 15. That is, the wire guide 15 is held at a certain relative position with respect to one part (thigh). In this example, the actuator 8 is connected to the connecting portion 15 by the wire 8 being laid over the wire guide 15. The fixed end 5 e of the actuator 5 is fixed to the other part (crus) in the crus fixing part 16. Similar to the example shown in FIG. 6A, the fixed end 5e of the actuator 5 in the example shown in FIG. 6B is connected to the telescopic body 9 and is connected by a connecting portion 32 (see FIG. 3A) fixed to the lower leg brace 4. Composed.

FIG. 6C shows an example in which the position of the rod-shaped member 17 is changed from the thigh brace 2 to the lower thigh brace 4. In this example, the stretchable body 9 is connected to the thigh brace 2 in this example, and one end of the wire 8 is fixed to a wire fixing portion 14 </ b> A formed on the rotation center axis of the wire guide 14 provided on the stretchable body 9. At the same time, the other end is extended toward the wire guide 14 of the stretchable body 9 via the wire guide 15 of the rod-like member 17 extending from the lower leg orthosis 4 and the thigh orthosis 2 via the wire guide 14. The wire guide 15 is fixed to a wire fixing portion 15A.

In the example shown in FIG. 6C, the connecting portion provided integrally with one portion (crus) is constituted by a wire guide 15. That is, the wire guide 15 is held at a certain relative position with respect to one part (crus). In this example, the actuator 5 is connected via a wire guide (connecting portion) 15 to a rod-like member 17 (projecting portion 13) fixed to one portion (crus). The fixed end 5 e of the actuator 5 is fixed to the other part (thigh) in the thigh-side fixing part 11. The actuator 5 has a stretchable body (distance varying means) 9 located on the other part (thigh) side, and a wire 8 located on the one part (crus) side and connected to the stretchable body 9. is doing. The actuator 5 is connected to the connection portion 15 by the wire 8 being stretched over the wire guide 15. The fixed end 5e of the actuator 5 is configured by a connection portion 32 (see FIG. 3A) that is connected to the stretchable body 9 and fixed to the thigh brace 2. The connection portion 32 is fixed to the mechanism attachment member 2 </ b> A of the thigh brace 2 by a fastener such as a bolt that penetrates the through hole 33.

Further, another embodiment of the motion assist device 1 will be described with reference to FIGS. 7A and 7B. 7A and 7B show an example in which the position of the lower leg brace 4 is changed to a foot. That is, this is an example in which the lower leg brace 4 is configured as the heel brace 3. The motion assist device 1 according to this example includes a thigh brace 2 attached to the thigh, a gut brace 3 attached to the heel, and an actuator 5 that applies driving force to the thigh brace 2 and the brace brace 3. The thigh brace 2 and the actuator 5 shown in FIG. 7B have the same configuration as that shown in FIG. Moreover, since the thigh orthosis 2 shown to FIG. 7A is the same structures as what was shown in FIG. 2, description is abbreviate | omitted. The actuator 5 shown in FIG. 7A is shown in FIG. 2 except that the end of the wire 8 on the side of the stretchable body 9 is fixed to the stretchable body 9 as it is without being folded back by a wire guide provided on the stretchable body 9. It has the same configuration as

In the example shown in FIGS. 7A and 7B, the connection portion provided integrally with one portion (thigh) is constituted by a wire guide 15. That is, in the example shown in FIGS. 7A and 7B, the wire guide 15 is held at a certain relative position with respect to one part (thigh). In this example, the actuator 8 is connected to the connecting portion 15 by the wire 8 being laid over the wire guide 15. The fixed end 5 e of the actuator 5 is configured by an end portion of the wire 8 that is opposite to the side connected to the expansion body 9.

The brace 3 includes a mechanism attachment member 3A and a wire fixing portion 35 to which one end of the wire 8 extending from the thigh side is attached. The mechanism attachment member 3A is formed, for example, so as to wrap a foot heel, and is fixed to the heel by a fixing belt 3B. The mechanism attachment member 3A is provided with a wire fixing portion 35 that can fix one end of the wire 8 (the fixed end 5e of the actuator 5) on the other end side of the actuator 5. The wire fixing portion 35 is configured to be connectable by turning back the wire 8, such as a circular hole or a screw hole, or by a fixing means such as a set screw. That is, the wire 8 is fixed to a foot as a second part connected to the lower leg as a first part constituting the other part connected to the thigh by the knee joint. .
The mechanism fixing member is positioned so that the wire fixing portion 35 is located within a diagonal θ ′ of the angle θ formed by the extension line p2 of the crus and the extension line p3 of the foot in a squatting posture (when the knee joint is bent). 3A.

By contracting the telescopic body 9, the wire guide 15 and the wire fixing portion 35 come close to each other, so that the thigh has a rotational moment in the extending direction around the wire guide 15 via the rod-shaped member 17 (see FIG. 7B middle arrow F1) acts, and a rotational moment in the extension direction around the rotation axis D of the ankle joint (arrow F2 in FIG. 7B) acts on the lower leg, so that the extension operation can be efficiently assisted. it can.

FIG. 8 is an example in which the stretchable body 9 is arranged between the wire guide 15 and the wire fixing portion 35 in the example shown in FIGS. 7A and 7B. In this example, the extension body 9 has one end portion of the wire 8A fixed to the wire fixing portion 35 of the brace 3 and the other end portion fixed to the through-hole 33 of the extension body 9 by screwing or the like. One end of the wire 8B is fixed to the wire fixing portion 15A of the wire guide 15, and the other end is fixed to the wire fixing portion 14A provided on the wire guide 14. Even if comprised in this way, the rotational moment of an extension direction can be made to act on a thigh part and a leg part.

In the example shown in FIG. 8, the connecting portion provided integrally with one portion (thigh) is constituted by a wire guide 15. That is, in the example shown in FIG. 8, the wire guide 15 is held at a certain relative position with respect to one part (thigh). In this example, the actuator 8 is connected to the connecting portion 15 by fixing the wire 8 to the wire fixing portion 15 </ b> A of the wire guide 15. The fixed end 5e of the actuator 5 is formed by the end of the wire 8B opposite to the side connected to the telescopic body 9, that is, the end of the wire 8B fixed to the mechanism mounting member 3A of the brace 3 at the fixed portion 35. It is configured.

Although not shown, one end of the stretchable body 9 may be connected to the foot, and the other end may be connected to the end of the wire 8 that extends from the thigh brace 2 via the wire guide 15. In this example, the fixed end 5e of the actuator 5 is constituted by one end of a telescopic body 9 fixed to the foot.

Further, another embodiment of the motion assist device 1 will be described with reference to FIG. FIG. 9 shows an example in which the position of the stretchable body 9 is changed to the back. In the motion assist device 1 according to this example, a rod-like member 17 attached to a thigh brace 2 attached to a thigh protrudes from both a knee joint and a waist joint, and includes wire guides 15 and 37 at both ends. The wire guide 37 is provided on the rod-shaped member 17 so as to be positioned within a diagonal η ′ of an angle η formed by the extension line p1 of the thigh and the extension line p4 of the trunk. One end side of the stretchable body 9 is connected to a back device that is not shown, and one end of the wire 8 is fixed to the other end side. The wire 8 having one end fixed to the stretchable body 9 extends toward the wire guide 15 via the wire guide 37 located on the waist side, and the other end is fixed to the wire fixing portion 35 via the wire guide 15. Is done.

By contracting the telescopic body 9, the wire guide 37 of the rod-shaped member 17 is lifted upward, and the wire guide 15 is rotated downward, so that the lower leg moves in the extending direction around the rotation axis D of the ankle joint. A rotational moment acts, a rotational moment in the extending direction around the rotational axis C of the knee joint acts on the thigh, and a rotational moment in the extending direction around the rotational axis E of the hip joint acts on the torso, The extension operation can be assisted more efficiently.

In the example shown in FIG. 9, similarly to the examples shown in FIGS. 7A to 8, the connecting portion provided integrally with one part (thigh) is constituted by the wire guide 15. . That is, in the example shown in FIG. 9, the wire guide 15 is held at a certain relative position with respect to one part (thigh). In this example, the actuator 8 is connected to the connecting portion 15 by the wire 8 being laid over the wire guide 15. The fixed end 5e of the actuator 5 is the end of the wire 8 that is opposite to the side connected to the telescopic body 9, that is, the end of the wire 8 fixed to the mechanism attachment member 3A of the brace 3 at the fixed portion 35. It is configured.

As described above, when the actuator 5 of the assist device 1 is composed of the stretchable body 9 and the wire 8, after reaching the stretched state, the stretcher stretches so as to release the tension of the artificial muscle 18 constituting the stretchable body 9. When the body 9 is extended, surplus is generated in the wire 8, and for example, the wire 8 may be detached from the wire guide 15 or the wire guide 14. Therefore, it is preferable to provide the assist device 1 with a length adjustment mechanism 60 that enables adjustment of the surplus of the wire 8.

10A to 10C are schematic views showing an embodiment of the length adjustment mechanism 60. FIG. The length adjustment mechanism 60 includes a tensioner 62 and a tensioner fixing mechanism 70.
The tensioner 62 is slidably assembled to the body 64 by inserting the guide shaft 66A of the slide member 66 into a guide hole 64A provided in the body 64. The guide shaft 66A of the slide member 66 is urged so that the slide member 66 protrudes from the body 64 by a spring (not shown) provided inside the body 64.

The tensioner fixing mechanism 70 includes, for example, a braking member 72 and a braking force generator 80. The braking member 72 includes a cap portion 76 and a braking plate 78. The cap part 76 is formed so as to be covered along the outer periphery of the head part 66 </ b> B of the slide member 66. The brake plate 78 is a flat plate that extends parallel to one side surface of the body 74 along the moving direction of the slide member 66 when the cap portion 76 is attached to the head portion 66B.

The braking force generator 80 includes a mounting plate 82, a braking force generator 84, and a friction material 86. The mounting plate 82 is a plate-like member that is fixed to one side surface of the body 64 of the tensioner 62, and includes an extension portion 82 </ b> A that extends along the extension direction of the brake plate 78. The braking force generator 84 extends toward the surface of the braking plate 78 so as to sandwich the braking plate 78 from both surfaces of the extension portion 82A. The braking force generator 84 is configured such that a wire 88 is attached to the base end 84 </ b> A side, and the distal end 84 </ b> B moves toward the braking plate 78 by pulling the wire 88. A friction material 86 is attached to the front end 84 </ b> B side of the braking force generator 84.
Therefore, the braking force generator 84 can fix the friction material 86 by sandwiching the braking plate 78 by pulling the wire 88.

The length adjustment mechanism 60 includes a plurality of wire guides 90. Specifically, as shown in FIG. 10A, the wire guide 90 is provided at two places on the body 64 of the tensioner 62, two places on the head portion 66B of the slide member 66, and two places on the mounting plate 82. The wire guides 90 provided on the body 64 and the mounting plate 82 of the tensioner 62 are arranged in a row in a direction orthogonal to the moving direction of the slide member 66. The wire guide 90 provided in the head portion 66B is arranged so as to be staggered with respect to the wire guide 90 provided on the body 64 and the mounting plate 82 of the rod tensioner 62. Then, one end side of the wire 8 is fixed to the wire fixing portion 82B provided on the attachment plate 82, and is hooked from the wire guide 90 of the attachment plate 82 to the wire guide 90 of the body 64 via the wire guide 90 of the head portion 66B. The other end side extends toward the wire guide 15 after being hooked from the wire guide 90 of the body 64 to the wire guide 90 of the mounting plate 82 via the wire guide 90 of the head portion 66B. The wire guide 90 is configured by a pulley, for example.

Hereinafter, the operation of the length adjusting mechanism 60 will be described.
As shown in FIG. 10C, for example, when tension is applied to the wire 8, the wire guide 90 provided in the head portion 66 </ b> B is pulled toward the body 64, whereby the slide member 66 is pushed into the body 64. Then, when the tension of the wire 8 is unloaded, the slide member 66 protrudes from the body 64 by the biasing force of the spring, as shown in FIG. 10A. Thereby, tension | tensile_strength can be provided to the wire 8 by winding up the excess wire 8. FIG.
Therefore, a larger assist torque can be obtained.
When it is desired to restrict the movement of the slide member 66, the movement of the slide member 66 is controlled by pulling the wire 88 and sandwiching the brake plate 78 of the brake member 72 attached to the slide member 66 with the friction material 86; 86. can do.

The length adjusting mechanism 60 is attached to, for example, the crus orthosis 4 or the heel orthosis 3, and, for example, when the knee joint is in a fully extended state, the wire 8 is set so that the slide member 66 of the tensioner 62 protrudes most. It is good to adjust the length.

By providing the length adjusting mechanism 60 in this way, it is possible to eliminate the need to double the pulling amount of the wire 8 by using a pulley for the wire guide 15 of the stretchable body 9. That is, by doubling the pulling amount of the wire 8 by the pulley, the assist force is halved. However, by eliminating the pulley, the contraction force of the expansion body 9 can be applied to the assist force.

In addition, since the length adjusting mechanism 60 includes the tensioner fixing mechanism 70 that restricts the movement of the slide member 66 of the tensioner 62, the tensioner fixing mechanism when the telescopic body 9 is contracted to exert the assist force. By operating 70, the slide member 66 of the tensioner 62 can be pushed into the body 64 and absorption of the traction stroke of the wire 8 can be prevented. That is, when the assist force is generated, the absorption of the tension applied to the wire 8 can be suppressed by fixing the slide member 66. That is, the length adjusting mechanism 60 can prevent the wire 8 from being stretched or bent.

In the present embodiment, the stretchable body 9 is composed of the two artificial muscles 18; 18. However, one or three or more may be provided in parallel according to the required assist force.
In addition, although it has been described that the stretchable body 9 is configured by the artificial muscle 18, an air cylinder or the like may be used when air is used as a drive source.
When electric power is used as a drive source for the expansion / contraction body 9, the expansion / contraction body 9 may be pulled by a combination of a ball screw mechanism and a linear motor, and the wire 8 may be pulled directly by a winder. You may make it take.
Further, in the above-described embodiment, the actuator 5 is described as being configured by the stretchable body 9 and the wire 8, but the connecting portion (for example, the wire guide 15) is fixed to the fixed end 5e (for example, the lower leg side fixing portion 16) of the actuator 5. As long as it can be pulled toward the end of the wire, rubber may be used. That is, the type of the actuator is not limited as long as it can pull and retract the wire 8.
In the above embodiment, the wire guide 15 and the rod-shaped member 17 are described as being provided on the side portion of the leg portion. However, the wire guide 15 is formed by two parts such as the thigh portion and the crus portion in the bent state. The positions of the wire guide 15 and the rod-shaped member 17 such as the front are not limited as long as they are located within the diagonal corners.

Claims (12)

1. An operation assist device that assists an operation when two parts connected by a joint change from a bent state to an extended state,
   A member fixed to one part;
   An actuator having a fixed end connected to the member via a connecting portion provided integrally with the member and fixed to the other part;
   The connecting portion is located within a diagonal angle formed by the two portions in the bent state,
   The actuator is an operation assist device capable of shortening a distance between the fixed end and the connection portion.
2. The operation assist device according to claim 1, wherein the actuator includes one of rubber and wire.
3. The actuator includes a wire;
   The motion assist device according to claim 1, further comprising a length adjusting mechanism capable of adjusting a length of the wire in a change of the two portions to an extended state or a bent state.
4. The operation assist device according to claim 3, wherein the length adjusting mechanism includes a tensioner that applies tension to the wire.
5. The actuator includes a distance varying means and a wire,
   The operation assist device according to any one of claims 1 to 4, wherein the wire is stretched over a pulley mechanism.
6. The extension distance adjustment means which adjusts the extension distance per unit time between the said fixed end and the said connection part when the said 2 site | part changes from an extended state to a bending state is provided. The operation assist device according to any one of claims 5 to 6.
7. The other part includes a first part, a second part, and a joint connecting the first part and the second part,
   The motion assist device according to any one of claims 1 to 6, wherein the fixed end of the actuator is fixed to the first part or the second part.
8. The operation according to any one of claims 1 to 7, wherein the operation assist device assists an operation when the thigh and the lower leg connected by a knee joint change from a bent state to an extended state. Assist device.
9. The motion assist device according to claim 8, wherein the connection portion between the member and the actuator is disposed on a side portion of the knee joint.
10. The actuator includes a distance varying means and a wire,
    The motion assist device according to claim 8 or 9, wherein the distance varying means is arranged on the thigh side.
11. The actuator includes a distance varying means and a wire,
    The motion assist device according to claim 8 or 9, wherein the distance varying means is arranged on the thigh side and the crus side.
12. An operation assist device for assisting an operation when a thigh and a lower leg connected by a knee joint change from a bent state to an extended state;
    A member fixed to the thigh;
    Distance varying means fixed to the member;
    A wire guide that is located within a diagonal of the angle between the thigh and the lower leg, and is provided integrally with the member;
    An operation assisting device comprising: a wire fixed to the lower leg and spanned over the distance changing means via the wire guide.

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