JP2018144169A - Driving apparatus for action assisting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving apparatus for an action assisting apparatus, in which a speed change ratio is changed based on a rotating direction or a rotational phase of a joint part of the action assisting apparatus.SOLUTION: There is provided a driving apparatus rotatively driving a joint part arranged on an action assisting apparatus which is put on a human body and assists action of the human body, which comprises a first driving pulley supported on a rotational shaft, a second driving pulley supported on the rotational shaft, an actuator outputting driving power for rotating the rotational shaft, a flexible driving power transmission member whose both end sides are wound on the first driving pulley and the second driving pulley, respectively, a driven pulley on which a middle section of the driving power transmission member is wound, a first clutch switches rotatively driving of the first driving pulley due to rotation torque from the rotational shaft and idle running, and a second clutch switches rotatively driving of the second driving pulley due to rotation torque from the rotational shaft and idle running, where a rotational transmission ratio from the rotational shaft to the driven pulley is different depending on a rotating direction and a rotational phase of the driven pulley.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a drive device for an operation assisting device that rotationally drives a joint portion provided in an operation assisting device that assists the movement of a human body.

  2. Description of the Related Art Human body-mounted robots are known as operation assistance devices that support or assist the movement of healthy or disabled people. The human body-mounted robot includes, for example, a joint unit worn by a user, a sensor for detecting the user's intention or operation state, a driving device that generates torque to be applied to the joint unit, and a control that controls the driving device. Device. For example, the drive device includes an electric motor and a speed reducer that converts high-speed rotation of the motor into low-speed rotation suitable for human movement. The transmission decelerates the rotation of the motor at a gear ratio of 1/50 to 1/200, for example. In such a drive device, a torque transmission mechanism including a plurality of pulleys and a power transmission member such as a flexible cable, wire, or belt may be used. A drive device using such a torque transmission mechanism has an advantage that the degree of freedom of arrangement of the drive device can be increased.

JP 2008-232360 A

  Here, the human body-mounted robot has a characteristic that the torque or rotational speed required for driving the joint is asymmetric depending on the rotational direction or rotational phase. For example, in a robot that assists the rotation of the knee joint in the front-rear direction, a relatively large torque in the direction of bending the joint is required during the operation of stepping on the leg, and only a small torque is required during the operation of shaking the leg. On the other hand, a relatively high rotational speed is required. Conventional drive devices use, for example, a plurality of symmetrical pulleys or a pulley mechanism that has a plurality of pulleys having the same diameter and has the same rotation transmission ratio regardless of the rotation direction. A high-power actuator that can cover the maximum torque and maximum speed required is required. For this reason, the drive device may be a heavy and expensive device, or energy efficiency may be reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to drive a motion assist device in which the rotation transmission ratio changes according to the rotation direction or the rotation phase of the joint portion of the motion assist device. To provide an apparatus.

  According to an aspect of the present invention, in a drive device that rotationally drives a joint portion provided in an operation assisting device that is attached to a human body and assists the movement of the human body, a first drive pulley supported by a rotation shaft; A second driving pulley supported by the rotating shaft, an actuator for outputting power for rotating the rotating shaft, and a flexible power transmission member having both ends wound around the first driving pulley and the second driving pulley, respectively. A driven pulley around which the intermediate portion of the power transmission member is wound, a first clutch that switches between rotation and idling of the first drive pulley by the rotation torque of the rotation shaft, and a second drive pulley by the rotation torque of the rotation shaft A second clutch that switches between rotation driving and idling, and the rotation transmission ratio from the rotation shaft to the driven pulley varies according to at least one of the rotation direction and rotation phase of the driven pulley. Drive of auxiliary devices is provided.

  According to another aspect of the present invention, in the driving device that rotationally drives the joint portion provided in the motion assisting device that is attached to the human body and assists the movement of the human body, the first driving supported by the rotating shaft A pulley, a second driving pulley supported by the rotating shaft, an actuator for outputting power for rotating the rotating shaft, a driven pulley driven by the rotational torque of the first driving pulley and the second driving pulley, A flexible first power transmission member having both ends wound around the first drive pulley and the driven pulley, and a flexible second power transmission member having both ends wound around the second drive pulley and the driven pulley, respectively. A first clutch that switches between rotation and idling of the first drive pulley by the rotation torque of the rotation shaft, and a second clutch that switches between rotation and idling of the second drive pulley by the rotation torque of the rotation shaft Includes a clutch, the rotation transmission ratio from the rotation shaft in accordance with at least one of the rotational direction and the rotational phase of the driven pulley to the driven pulley are different, the driving device of the operation assisting device is provided.

  According to still another aspect of the present invention, in the driving device that rotationally drives the joint portion provided in the motion assisting device that is attached to the human body and assists the motion of the human body, the first supported by the rotating shaft. The driving pulley, the second driving pulley supported by the rotating shaft, the first driven pulley supported by the driven shaft, the second driven pulley supported by the driven shaft, and the rotating shaft are rotated. An actuator for outputting power, a flexible first power transmission member having both ends wound around a first drive pulley and a first driven pulley, and a second drive pulley and a second driven pulley at both ends, respectively. A flexible second power transmission member that winds around the first clutch, a first clutch that switches rotation and idling of the first drive pulley by the rotation torque of the rotation shaft, and a second drive pulley by the rotation torque of the rotation shaft Rotational drive and And a second clutch that switches rotation, and a drive device for an operation assisting device is provided that has different rotation transmission ratios from the rotation shaft to the driven shaft according to at least one of the rotation direction and the rotation phase of the driven shaft. The

  As described above, according to the present invention, the rotation transmission ratio can be changed according to the rotation direction or the rotation phase of the joint portion of the motion assisting device.

It is a schematic diagram which shows the structural example of the drive device of the operation assistance apparatus which concerns on the 1st Embodiment of this invention. It is the schematic diagram which looked at the drive device of the movement auxiliary device concerning the embodiment along the direction of an axis of a rotating shaft. It is explanatory drawing which shows the compensation mechanism of the drive device of the operation assistance apparatus which concerns on the same embodiment. It is explanatory drawing which shows the operation assistance apparatus to which the drive device of the operation assistance apparatus which concerns on the same embodiment is applied. It is explanatory drawing which shows the compensation mechanism of the drive device of the operation assistance apparatus which concerns on a 1st modification. It is explanatory drawing which shows the 1st example of the pulley from which a radius differs according to a rotation phase. It is explanatory drawing which shows the 2nd example of the pulley from which a radius differs according to a rotation phase. It is explanatory drawing which shows the 3rd example of the pulley from which a radius differs according to a rotation phase. It is a schematic diagram which shows the structural example of the drive device of the operation assistance apparatus which concerns on the 3rd modification of the embodiment. It is a schematic diagram which shows the structural example of the drive device of the operation assistance apparatus which concerns on the 2nd Embodiment of this invention. It is the schematic diagram which looked at the drive device of the movement auxiliary device concerning the embodiment along the direction of an axis of a rotating shaft.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<< 1. First embodiment >>
<1-1. Configuration Example of Drive Device>
With reference to FIG.1 and FIG.2, the drive device 10 of the operation assistance apparatus which concerns on this embodiment is demonstrated. 1 and 2 are schematic diagrams illustrating a configuration example of the driving device 10 of the motion assisting device. FIG. 1 is a schematic diagram of the driving device 10 viewed from a direction orthogonal to the axial direction of the rotating shaft 17, and FIG. 2 is a schematic diagram of the driving device 10 viewed along the axial direction of the rotating shaft 17.

  The drive device 10 includes a flexible cable 9, a first drive pulley 3, a second drive pulley 5, a driven pulley 1, an actuator 11, and a speed reducer 15. The first drive pulley 3 and the second drive pulley 5 are supported coaxially by a common rotating shaft 17. The first drive pulley 3 has, for example, a first winding portion 3a around which the flexible cable 9 is wound on the outer peripheral surface. Moreover, the 2nd drive pulley 5 has the 2nd winding part 5a in which the flexible cable 9 winds around an outer peripheral surface, for example. The diameter D2 of the 2nd winding part 5a is smaller than the diameter D1 of the 1st winding part 3a.

  Both ends of the flexible cable 9 are fixed or wound around the first drive pulley 3 and the second drive pulley 5, respectively, and an intermediate portion of the flexible cable 9 is wound around the driven pulley 1. Specifically, a portion 9 a on one end side of the flexible cable 9 led out from the driven pulley 1 is fixed or wound around the first drive pulley 3, and the other end of the flexible cable 9 led out from the driven pulley 1. The side portion 9 b is fixed or wound around the second drive pulley 5. The flexible cable 9 may be fixed by being wound around the first drive pulley 3 and the second drive pulley 5 a plurality of times.

  As the flexible cable 9, for example, a cable made of steel or synthetic fiber is used. Among them, a synthetic fiber cable is superior in durability in a winding operation around a pulley having a relatively small diameter as compared with a steel cable, and thus is a cable applied to the drive device 10 that is desired to be downsized. More preferred.

  In the above description, the flexible cable 9 is a single cable connected from the end portion 9a to the other end portion 9b. However, the flexible cable 9 is divided into two. Also good. For example, the flexible cable has a first flexible cable 9 a fixed at both ends to the first drive pulley 3 and the driven pulley 1, and both ends connected to the second drive pulley 5 and the driven pulley 1, respectively. A fixed second flexible cable 9b may be included. In this case, the flexible cables 9 a and 9 b may be fixed by being wound around the first driving pulley 3, the second driving pulley 5 and the driven pulley 1 a plurality of times.

  The actuator 11 outputs motive power (rotational torque) for rotating the rotary shaft 17 that supports the first drive pulley 3 and the second drive pulley 5. The actuator 11 can output bidirectional rotational torque. The driving of the actuator 11 is controlled by a control device (not shown). In the drive device 10 according to the present embodiment, the rotational torque output from the actuator 11 is transmitted to the rotary shaft 17 via the speed reducer 15. As the actuator 11, an electric drive type rotary motor is typically used. However, the actuator 11 is not limited to a rotary motor, and may be, for example, an actuator that combines an electrically driven linear motor and a torque conversion mechanism that converts a linear motion of the linear motor into a rotational motion.

  The reduction gear 15 decelerates the rotation output from the actuator 11 at a predetermined reduction ratio and transmits the rotation to the rotary shaft 17. As the speed reducer 15, a known speed reducer is appropriately used. The reduction gear 15 may be a wave gear device, for example.

  The winding direction of the flexible cable 9a around the first driving pulley 3 and the winding direction of the flexible cable 9b around the second driving pulley 5 are opposite to each other. When the flexible cable 9 is wound, the flexible cable 9 is led out from the other drive pulley. As the first drive pulley 3 and the second drive pulley 5 rotate in both directions by the rotational drive of the actuator 11, the rotational torque is transmitted to the driven pulley 1 via the flexible cable 9. In FIG. 2, when the rotating shaft 17 rotates clockwise, the second drive pulley 5 winds up the flexible cable 9, and the driven pulley 1 rotates clockwise. Further, when the rotating shaft 17 rotates counterclockwise, the first drive pulley 3 winds up the flexible cable 9 and the driven pulley 1 rotates counterclockwise. Thereby, the driven pulley 1 can output bidirectional rotational torque.

  As described above, the diameter D2 of the second winding portion 5a in the second drive pulley 5 is smaller than the diameter D1 of the first winding portion 3a in the first drive pulley 3. That is, the winding amount of the flexible cable 9 around the first drive pulley 3 and the flexibility to the second drive pulley 5 when the rotary shaft 17 is rotated in either direction at the same rotational speed. The winding amount of the cable 9 is different. Therefore, the rotation transmission ratio from the rotating shaft 17 to the driven pulley 1 when the first drive pulley 3 winds the flexible cable 9 is the same as that when the second drive pulley 5 winds the flexible cable 9. The rotation transmission ratio from the rotary shaft 17 to the driven pulley 1 is larger. Thereby, the drive device 10 in which the rotation transmission ratio differs depending on the rotation direction of the driven pulley 1 is realized.

  Here, the driving device 10 compensates for the difference between the winding amount and the derivation amount of the flexible cable 9 by the first driving pulley 3 and the second driving pulley 5 when the rotating shaft 17 rotates in both directions. A compensation mechanism is provided. FIG. 3 is an explanatory diagram showing a compensation mechanism of the driving apparatus 10 according to the present embodiment. In FIG. 3, the first drive pulley 3 and the second drive pulley 5 that are supported on the same rotating shaft 17 are shown separately for easy understanding.

  The drive device 10 according to the present embodiment includes a first two-way clutch 21, a second two-way clutch 23, and a torsion spring 25 as a compensation mechanism. The first drive pulley 3 is supported on the rotary shaft 17 via the first two-way clutch 21, and the second drive pulley 5 is supported on the rotary shaft 17 via the second two-way clutch 23. Further, the first drive pulley 3 includes a torsion spring 25 that applies a tension that pulls the flexible cable 9 a in the winding direction around the first drive pulley 3. For example, one end of the torsion spring 25 is fixed to the first drive pulley 3, the other end is fixed to the rotating shaft 17, and the central portion is wound around the rotating shaft 17.

  The first two-way clutch 21 corresponds to a first clutch that switches between rotational driving and idling of the first driving pulley 3 by the rotational torque of the rotating shaft 17. The first two-way clutch 21 is locked when the rotational speed Na of the rotational shaft 17 is larger than the rotational speed Nd1 of the first drive pulley 3 regardless of the rotational direction of the rotational shaft 17. Is transmitted to the first drive pulley 3. On the other hand, the first two-way clutch 21 is unlocked when the rotation speed Na of the rotation shaft 17 is smaller than the rotation speed Nd1 of the first drive pulley 3, regardless of the rotation direction of the rotation shaft 17. The first drive pulley 3 is idled.

  The second two-way clutch 23 corresponds to a second clutch that switches between rotational driving and idling of the second driving pulley 5 by the rotational torque of the rotating shaft 17. The second two-way clutch 23 is locked when the rotational speed Na of the rotational shaft 17 is larger than the rotational speed Nd2 of the second drive pulley 5 regardless of the rotational direction of the rotational shaft 17. Is transmitted to the second drive pulley 5. On the other hand, the second two-way clutch 23 is unlocked when the rotation speed Na of the rotation shaft 17 is smaller than the rotation speed Nd2 of the second drive pulley 5 regardless of the rotation direction of the rotation shaft 17. The second drive pulley 5 is idled.

  A known two-way clutch can be used as each of the first two-way clutch 21 and the second two-way clutch 23.

  In FIG. 3, when the rotation shaft 17 rotates counterclockwise, the rotation speed Nd1 of the first drive pulley 3 becomes smaller than the rotation speed Na of the rotation shaft 17 due to the tension of the flexible cable 9a. Therefore, the first two-way clutch 21 is locked, and the first drive pulley 3 is rotationally driven by the rotational torque of the rotary shaft 17. Therefore, the driven pulley 1 rotates counterclockwise when the first drive pulley 3 winds the flexible cable 9a. At this time, since the diameter D2 of the second winding portion 5a of the second driving pulley 5 is smaller than the diameter D1 of the first winding portion 3a of the first driving pulley 3, the flexible cable 9b The rotational speed Nd2 of the second drive pulley 5 rotated by the tension is greater than the rotational speed Na of the rotating shaft 17. For this reason, the second two-way clutch 23 is unlocked, the second drive pulley 5 is idling, and the tension of the flexible cable 9b is maintained. Thus, the winding amount of the flexible cable 9 by the first drive pulley 3 and the lead-out amount of the flexible cable 9 by the second drive pulley 5 when the rotating shaft 17 rotates counterclockwise. And the difference is compensated.

  3, when the rotation shaft 17 rotates clockwise, the rotation speed Nd2 of the second drive pulley 5 becomes smaller than the rotation speed Na of the rotation shaft 17 due to the tension of the flexible cable 9b. For this reason, the second two-way clutch 23 is locked, and the second drive pulley 5 is driven to rotate by the rotational torque of the rotary shaft 17. Therefore, the driven pulley 1 rotates clockwise as the second drive pulley 5 winds the flexible cable 9b. At this time, the diameter D2 of the second wrapping portion 5a of the second drive pulley 5 is smaller than the diameter D1 of the first wrapping portion 3a of the first drive pulley 3. The rotation transmission ratio to 1 is smaller than when the rotating shaft 17 rotates counterclockwise.

  Moreover, since the diameter D2 of the 2nd winding part 5a of the 2nd driving pulley 5 is smaller than the diameter D1 of the 1st winding part 3a of the 1st driving pulley 3, it arises in the flexible cable 9a. The tension is small, and the rotation speed Na of the rotating shaft 17 is larger than the rotation speed Nd1 of the first drive pulley 3. Therefore, the first two-way clutch 21 is locked, and the first drive pulley 3 is rotationally driven by the rotational torque of the rotary shaft 17. At this time, the torsion spring 25 provided on the first drive pulley 3 pulls the flexible cable 9 a in the winding direction around the first drive pulley 3. For this reason, the slackness of the flexible cable 9a is suppressed, and the tension of the flexible cable 9a is maintained. Thus, the winding amount of the flexible cable 9 by the second drive pulley 5 when the rotating shaft 17 rotates clockwise, and the lead-out amount of the flexible cable 9 by the first drive pulley 3. The difference is compensated.

  As described above, the driving device 10 of the motion assist device according to the present embodiment can vary the rotation transmission ratio from the rotating shaft 17 to the driven pulley 1 depending on the rotation direction of the driven pulley 1. For this reason, even when the driving device 10 drives the rotating shaft 17 at the same rotational speed, the rotational speed and rotational torque of the joint portion of the motion assisting device can be changed depending on the rotational direction of the driven pulley 1. Therefore, when the driven pulley 1 is rotated in a certain rotation direction, it can be rotated at a low torque and a high speed, and when it is rotated in another rotation direction, it can be rotated at a high torque and a low speed. As a result, an actuator having a relatively small output can be used as the actuator 11 to be used, and the weight and cost can be reduced, and the energy efficiency can be improved.

<1-2. Application example to motion assist device>
Next, with reference to FIG. 4, an example in which the driving device 10 of the motion assisting device according to the above embodiment is applied to a human body wearing robot 100 as the motion assisting device will be described. FIG. 4 is an explanatory diagram illustrating an example of the human-body-mounted robot 100 that rotates the active joint unit 120 with the power generated by the actuator 11 of the driving device 10. FIG. 4 is a schematic diagram shown for ease of understanding, and the drive device 10 may actually be accommodated in, for example, a case or a bag and placed on the waist or back of a human body, or an active joint. It may be disposed adjacent to the portion 120.

  The illustrated human body-mounted robot 100 includes an active joint unit 120, a passive joint unit 123, a first arm unit 112 and a second arm unit 114 connected via the passive joint unit 123, and an active joint unit 120. And a third arm portion 116 connected to the second arm portion 114 via the second arm portion 114. The passive joint part 123 is located on the side of the hip joint of the human body and connects the first arm part 112 and the second arm part 114 in a rotatable manner. The active joint portion 120 is located on the side of the knee joint of the human body and connects the second arm portion 114 and the third arm portion 116 so as to be rotatable.

The upper part of the first arm portion 112 is fixed to a mounting belt 102 that is wrapped around the waist of a human body. The lower portion of the second arm portion 114 is fixed to a mounting belt 104 that is wound around the thigh of the human body. The lower portion of the third arm portion 116 is fixed to a mounting belt 106 that is wound around the lower leg portion of the human body. The active joint 120 is provided with the driven pulley 1, and the relative rotation between the second arm 114 and the third arm 116 around the active joint 120 is driven via the flexible cable 9. Driven by device 10.

  For example, two flexible cables 9a and 9b are connected to the driven pulley 1 of the active joint portion 120, and either one of the flexible cables is sent out toward the active joint portion 120, and the other flexible cable. Is retracted from the active joint portion 120, the third arm portion 116 is rotated clockwise or counterclockwise with respect to the second arm portion 114. The respective ends of the flexible cables 9 a and 9 b are fixed or wound around the first drive pulley 3 or the second drive pulley 5 of the drive device 10. The illustrated flexible cables 9a and 9b are configured as Bowden cables in which cables made of wire, resin, or the like are covered with covers 131 and 132, and one ends of the covers 131 and 132 are fixed to the second arm portion 114. The distal ends of the flexible cables 9a and 9b can advance and retract with respect to the active joint 120. The flexible cables 9a and 9b may be a single flexible cable 9 that is wound around the driven pulley 1 and led out.

  In such a human body-mounted robot 100, for example, when a user (wearer) walks, the third arm portion 116 is rotated clockwise around the active joint portion 120, thereby assisting the stepping operation of the user's foot. Is done. For example, when a control device (not shown) detects the user's intention to step on the foot using a myoelectric potential sensor, a sensor for detecting the movement of the user's foot, or the like, the first drive pulley 3 takes up the flexible cable 9a. 11 is driven. As a result, the flexible cable 9 a is retracted from the active joint portion 120, while the flexible cable 9 b is sent out toward the active joint portion 120. As a result, the driven pulley 1 rotates counterclockwise, and the third arm portion 116 rotates counterclockwise around the active joint portion 120 until the user steps on the foot and kicks the foot up. A force that assists the movement is generated.

  On the other hand, when the user attempts to lower his / her foot after kicking his / her foot up, the control device (not shown) drives the actuator 11 so that the second drive pulley 5 winds up the flexible cable 9b. As a result, the flexible cable 9 b is retracted from the active joint 120, while the flexible cable 9 a is sent out toward the active joint 120. As a result, the driven pulley 1 rotates clockwise, and the third arm portion 116 rotates clockwise around the active joint portion 120 until the user kicks up the foot and lowers the foot. An assisting force is generated.

  At this time, since the diameter D2 of the second winding portion 5a of the second driving pulley 5 is smaller than the diameter D1 of the first winding portion 3a of the first driving pulley 3, the user steps in the foot. The rotational speed or rotational torque of the active joint 120 during assisting the operation from kicking up to kicking the foot relatively increases. On the other hand, the rotational speed or rotational torque of the active joint 120 is relatively small while assisting the operation from when the user kicks the foot up until the user lowers the foot. Therefore, the rotational speed or rotational torque of the active joint 120 can be changed according to the auxiliary force required according to the movement of the human body. Therefore, when the active joint 120 is rotated in a certain rotation direction, it can be rotated at a low torque and a high speed, and when it is rotated in another rotation direction, it can be rotated at a high torque and a low speed. As a result, an actuator having a relatively small output can be used as the actuator 11 to be used, and the weight and cost can be reduced, and the energy efficiency can be improved.

<1-3. Modification>
Various modifications can be made to the driving device 10 of the motion assisting device according to the above-described embodiment described so far. Hereinafter, some modified examples of the driving device 10 of the motion assist device according to the embodiment will be described.

(1-3-1. First Modification)
The driving device of the operation assisting device according to the first modification is different from the driving device 10 of the operation assisting device according to the embodiment in the configuration of the compensation mechanism. FIG. 5 is a schematic diagram illustrating a compensation mechanism of the driving device 70 according to the first modification, and corresponds to FIG. 3 described above. In FIG. 5, the first drive pulley 3 and the second drive pulley 5 that are supported by the same rotating shaft 17 are shown separately for easy understanding.

  The drive device 70 includes a one-way clutch 71, a two-way clutch 23, and a torsion spring 75 as a compensation mechanism. The first drive pulley 3 is supported on the rotary shaft 17 via a one-way clutch 71, and the second drive pulley 5 is supported on the rotary shaft 17 via a two-way clutch 23. The first drive pulley 3 includes a torsion spring 75 that applies tension that pulls the first drive pulley 3 in the winding direction of the flexible cable 9a. For example, one end of the torsion spring 75 is fixed to the first drive pulley 3, the other end is fixed to the rotating shaft 17, and the central portion is wound around the rotating shaft 17. Since the two-way clutch 23 corresponds to the second two-way clutch 23 according to the above-described embodiment, the description thereof is omitted below.

  The one-way clutch 71 corresponds to a first clutch that switches between rotational driving or idling of the first driving pulley 3 by the rotational torque of the rotating shaft 17. The one-way clutch 71 allows relative rotation of the first drive pulley 3 in one direction with respect to the rotation shaft 17 and suppresses relative rotation of the first drive pulley 3 in the other direction. Specifically, the one-way clutch 71 is locked when the first drive pulley 3 rotates relative to the rotation shaft 17 in the clockwise direction of FIG. Is transmitted to the drive pulley 3. On the other hand, the one-way clutch 71 is unlocked when the first drive pulley 3 rotates relative to the rotation shaft 17 in the counterclockwise direction of FIG. 5 and causes the first drive pulley 3 to idle. .

  In FIG. 5, when the rotary shaft 17 rotates counterclockwise, the one-way clutch 71 is locked, and the first drive pulley 3 is driven to rotate by the rotational torque of the rotary shaft 17. Therefore, the driven pulley 1 rotates counterclockwise when the first drive pulley 3 winds the flexible cable 9a. At this time, since the diameter D2 of the second winding portion 5a of the second driving pulley 5 is smaller than the diameter D1 of the first winding portion 3a of the first driving pulley 3, the flexible cable 9b The rotational speed Nd2 of the second drive pulley 5 rotated by the tension is greater than the rotational speed Na of the rotating shaft 17. For this reason, the two-way clutch 23 is unlocked, the second drive pulley 5 is idling, and the tension of the flexible cable 9b is maintained. Thus, the winding amount of the flexible cable 9 by the first drive pulley 3 and the lead-out amount of the flexible cable 9 by the second drive pulley 5 when the rotating shaft 17 rotates counterclockwise. And the difference is compensated.

  Further, when the rotating shaft 17 rotates clockwise in FIG. 5, the rotation speed Nd2 of the second drive pulley 5 becomes smaller than the rotation speed Na of the rotation shaft 17 due to the tension of the flexible cable 9b. For this reason, the two-way clutch 23 is locked, and the second drive pulley 5 is rotationally driven by the rotational torque of the rotary shaft 17. Therefore, the driven pulley 1 rotates clockwise as the second drive pulley 5 winds the flexible cable 9b. At this time, the diameter D2 of the second wrapping portion 5a of the second drive pulley 5 is smaller than the diameter D1 of the first wrapping portion 3a of the first drive pulley 3. The rotation transmission ratio to 1 is smaller than when the rotating shaft 17 rotates counterclockwise.

  Further, when the rotating shaft 17 rotates clockwise, the one-way clutch 71 is unlocked and the first drive pulley 3 rotates idly, but the first cable is wound by the tension of the flexible cable 9a wound around the driven pulley 1. 1 drive pulley 3 rotates clockwise. At this time, since the diameter D2 of the second winding portion 5a of the second driving pulley 5 is smaller than the diameter D1 of the first winding portion 3a of the first driving pulley 3, the first driving pulley 3 Since the rotation speed Nd1 of the rotation shaft 17 is smaller than the rotation speed Na of the rotation shaft 17, the first drive pulley 3 rotates clockwise while idling on the rotation shaft 17. For this reason, the slackness of the flexible cable 9a is suppressed, and the tension of the flexible cable 9a is maintained. Thus, the winding amount of the flexible cable 9 by the second drive pulley 5 when the rotating shaft 17 rotates clockwise, and the lead-out amount of the flexible cable 9 by the first drive pulley 3. The difference is compensated.

  As described above, the drive device 70 of the motion assist device according to the first modification can vary the rotation transmission ratio from the rotating shaft 17 to the driven pulley 1 depending on the rotation direction of the driven pulley 1. For this reason, even when the driving device 10 drives the rotating shaft 17 at the same rotational speed, the rotational speed and rotational torque of the joint portion of the motion assisting device can be changed depending on the rotational direction of the driven pulley 1. Therefore, when the driven pulley 1 is rotated in a certain rotation direction, it can be rotated at a low torque and a high speed, and when it is rotated in another rotation direction, it can be rotated at a high torque and a low speed. As a result, an actuator having a relatively small output can be used as the actuator 11 to be used, and the weight and cost can be reduced, and the energy efficiency can be improved.

(1-3-2. Second modification)
The driving device of the motion assisting device according to the second modification is a driving device having different rotation transmission ratios according to the rotation phase instead of the rotation direction of the driven pulley 1 or in combination with the rotation direction. FIGS. 6-8 has shown the structural example of the pulley used as a drive pulley of the drive device of the operation assistance apparatus which concerns on a 2nd modification.

  In the pulleys 61, 63, and 65 shown in FIGS. 6 to 8, the radii r of the flexible cable winding portions 61a, 63a, and 65a are different depending on the rotation phase. The pulley 61 shown in FIG. 6 is an example in which the radius r of the winding portion 61a of the flexible cable changes smoothly according to the rotational phase θ. Moreover, the pulley 63 shown in FIG. 7 is an example in which the radius r of the winding portion 63a of the flexible cable changes discontinuously according to the rotational phase θ. Moreover, the pulley 65 shown in FIG. 8 is an example which has the part where the radius r of the winding part 65a of a flexible cable changes smoothly according to the rotation phase (theta), and the part which changes discontinuously.

  By using the pulleys 61, 63, 65 illustrated in FIGS. 6 to 8 as at least one of the first driving pulley and the second driving pulley, the flexible cable is wound by the pulleys 61, 63, 65. When the driven pulley 1 is rotationally driven, the rotation transmission ratio from the rotary shaft 17 to the driven pulley 1 can be varied according to the rotational phase θ. Accordingly, by using a pulley in which an appropriate radius r is set for each rotation phase θ according to the operation of the user of the motion assisting device, an appropriate rotation speed and torque are realized according to the rotation phase θ of the joint part. be able to. In addition, the shape of a pulley is not restricted to the example shown in FIGS.

(1-3-3. Third Modification)
The driving device of the motion assisting device according to the third modification is a driving device in which the first driving pulley 3 and the second driving pulley 5 are supported on different rotating shafts. FIG. 9 is a diagram illustrating a configuration example of the driving device 80 according to the third modification, and corresponds to FIG. 2 described above.

  In the driving device 80 of the operation assisting device according to the third modification, the first driving pulley 3 is supported by the first rotating shaft 81 and the second driving pulley 5 is supported by the second rotating shaft 83. Yes. Among these, the 1st rotating shaft 81 is an output shaft of the actuator or speed reducer which is not shown in figure. The first rotating shaft 81 has a first gear 85 that rotates in synchronization with the first rotating shaft 81, and the second rotating shaft 83 rotates in synchronization with the second rotating shaft 83. The second gear 87 is provided. The first gear 85 and the second gear 87 are in mesh with each other, and the second rotary shaft 83 is also driven to rotate by the first rotary shaft 81 being driven to rotate by the actuator. In the example shown in FIG. 9, the number of teeth of the first gear 85 and the number of teeth of the second gear 87 are the same, and the first gear 85 and the second gear 87 rotate at the same rotational speed. Driven.

  Also in the driving device 80 according to the third modification, the diameter of the winding portion in the first driving pulley 3 is larger than the diameter of the winding portion in the second driving pulley 5. When the first drive pulley 3 winds up the flexible cable 9a, the second drive pulley 5 leads out the flexible cable 9b, and the second drive pulley 5 winds up the flexible cable 9b. In this case, the winding direction of the flexible cable 9 is set so that the first drive pulley 3 leads the flexible cable 9a. Other than this, it can be configured in the same manner as the driving apparatus 10 according to the above-described embodiment.

  The rotation transmission ratio from the first rotating shaft 81 to the driven pulley 1 can be varied according to the rotation direction of the driven pulley 1 also by the driving device 80 of the motion assist device according to the third modification. For this reason, the drive device 80 can change the rotation speed and the rotation torque of the joint portion of the motion assisting device according to the rotation direction of the driven pulley 1 even when the rotation shaft 17 is driven at the same rotation speed. Therefore, when the driven pulley 1 is rotated in a certain rotation direction, it can be rotated at a low torque and a high speed, and when it is rotated in another rotation direction, it can be rotated at a high torque and a low speed. As a result, an actuator having a relatively small output can be used as the actuator 11 to be used, and the weight and cost can be reduced, and the energy efficiency can be improved.

  The driving device 80 according to the third modification may be combined with the configuration of the driving device according to the first modification and the second modification. Further, the output shaft of the actuator may be connected to the rotating shaft 83 of the second driving pulley 5 instead of being connected to the rotating shaft 81 of the first driving pulley 3.

  In the drive device 80 shown in FIG. 9, the first rotary shaft 81 and the second rotary shaft 83 are configured to be rotatable at the same rotational speed, and the diameter of the first drive pulley 3 and the second The diameter of the first drive pulley 5 is different from the diameter of the first drive pulley 5 while the diameter of the first drive pulley 3 is the same as the diameter of the second drive pulley 5. It may be less than the number of teeth. Also with the drive device 80 having such a configuration, the rotation transmission ratio from the first rotating shaft 81 to the driven pulley 1 can be varied according to the rotation direction of the driven pulley 1.

<< 2. Second embodiment >>
<2-1. Configuration Example of Drive Device>
The driving device of the operation assisting device according to the second embodiment of the present invention is different from the driving device 10 of the operation assisting device according to the first embodiment in that it includes two driven pulleys. Hereinafter, the driving apparatus according to the second embodiment will be described mainly with respect to differences from the driving apparatus 10 according to the first embodiment.

  10 and 11 are schematic diagrams illustrating a configuration example of the driving device 90 of the motion assist device according to the present embodiment. FIG. 10 is a schematic diagram of the driving device 90 viewed from a direction orthogonal to the axial direction of the rotating shaft 17, and FIG. 11 is a schematic diagram of the driving device 90 viewed along the axial direction of the rotating shaft 17.

  The driving device 90 includes flexible cables 9a and 9b, a first driving pulley 91, a second driving pulley 92, a first driven pulley 93, a second driven pulley 94, an actuator 11, A reduction gear 15 is provided. The first drive pulley 91 and the second drive pulley 92 shown in FIGS. 10 and 11 have winding portions 91a and 92a having the same diameter. In the illustrated example, the first drive pulley 91 and the second drive pulley 92 have the same diameter, and flexible cables 9a and 9b are wound around the outer peripheral surface.

  The first driven pulley 93 and the second driven pulley 94 have winding portions 93a and 94a having different diameters, and the diameter D3 of the winding portion 93a of the first driven pulley 93 is the second driven pulley. It is smaller than the diameter D4 of the winding portion 94a of the pulley 94. In the illustrated example, the first driven pulley 93 and the second driven pulley 94 have different diameters, and flexible cables 9a and 9b are wound around the outer peripheral surface. The first driven pulley 93 and the second driven pulley 94 are fixed to the same driven shaft 95.

  In the drive device 90 according to the present embodiment, one end side of the flexible cable 9a is fixed or wound around the first drive pulley 91, and the other end side is fixed or wound around the first driven pulley 93. Further, one end side of the flexible cable 9b is fixed or wound around the second drive pulley 92, and the other end side is fixed or wound around the second driven pulley 94.

  In the present embodiment, the diameter of the first drive pulley 91 and the diameter of the second drive pulley 92 are the same, and the first driven pulley 91 when the rotary shaft 17 is rotated in both directions at the same rotational speed. The winding amount of the flexible cable 9a is equal to the winding amount of the flexible cable 9b by the second driven pulley 92. On the other hand, since the diameter D3 of the winding portion 93a in the first driven pulley 93 is smaller than the diameter D4 of the winding portion 94a in the second driven pulley 94, the rotary shaft 17 is rotated in both directions at the same rotational speed. The rotational speed of the first driven pulley 93 is different from the rotational speed of the second driven pulley 94. That is, the rotation transmission ratio from the rotating shaft 17 to the driven shaft 95 when the first driving pulley 91 winds the flexible cable 9a and the second driving pulley 92 when winding the flexible cable 9b. The rotation transmission ratio from the rotating shaft 17 to the driven shaft 95 is different. Thereby, the drive device 90 having a different rotation transmission ratio depending on the rotation direction of the driven shaft 95 is realized.

  Also in the driving device 90 according to the present embodiment, for compensating for the difference between the winding amount and the derivation amount between the first driven pulley 93 and the second driven pulley 94 when the rotating shaft 17 rotates in both directions. Compensation mechanism is provided. The compensation mechanism includes the first two-way clutch interposed between the first drive pulley 91 and the rotary shaft 17, the second drive pulley 92, and the rotary shaft 17, as in the drive device 10 according to the above embodiment. And a second two-way clutch interposed therebetween. Even in this case, the first drive pulley 91 is provided with a torsion spring 25 that applies tension for pulling the flexible cable 9 a in the winding direction around the first drive pulley 3. As described in the first modification of the first embodiment, a one-way clutch may be used instead of the first two-way clutch.

  In FIG. 11, when the rotation shaft 17 rotates clockwise, the rotation speed Nd1 of the first drive pulley 91 becomes smaller than the rotation speed Na of the rotation shaft 17 due to the tension of the flexible cable 9a. For this reason, the first two-way clutch is locked, and the first drive pulley 91 is rotationally driven by the rotational torque of the rotating shaft 17. Therefore, when the first drive pulley 91 winds the flexible cable 9a, the first driven pulley 93, the second driven pulley 94, and the driven shaft 95 rotate clockwise. At this time, since the diameter D3 of the winding portion 93a of the first driven pulley 93 is smaller than the diameter D4 of the winding portion 94a of the second driven pulley 94, the flexible cable 9b by the second driven pulley 94 is used. Is greater than the lead-out amount of the flexible cable 9 a by the first driven pulley 93.

  For this reason, the tension | tensile_strength of the flexible cable 9b becomes large, and the rotation speed Nd2 of the 2nd drive pulley 92 becomes larger than the rotation speed Na of the rotating shaft 17. FIG. As a result, the second two-way clutch is unlocked, the second drive pulley 92 is idling, the flexible cable 9b is led out from the second drive pulley 92, and the tension of the flexible cable 9b is reached. Is maintained. In this way, the lead-out amount of the flexible cable 9a by the first driven pulley 93 and the winding amount of the flexible cable 9b by the second driven pulley 94 when the rotating shaft 17 rotates in the clockwise direction. The difference is compensated.

  In addition, when the rotation shaft 17 rotates counterclockwise in FIG. 11, the rotation speed Nd2 of the second drive pulley 92 becomes smaller than the rotation speed Na of the rotation shaft 17 due to the tension of the flexible cable 9b. For this reason, the second two-way clutch is locked, and the second drive pulley 92 is rotationally driven by the rotational torque of the rotating shaft 17. Therefore, when the second driving pulley 92 winds the flexible cable 9b, the second driven pulley 94, the first driven pulley 93, and the driven shaft 95 rotate counterclockwise. At this time, since the diameter D3 of the winding portion 93a of the first driven pulley 93 is smaller than the diameter D4 of the winding portion 94a of the second driven pulley 94, rotation transmission from the rotary shaft 17 to the driven shaft 95 is achieved. The ratio is smaller than when the rotating shaft 17 rotates clockwise.

  Further, since the diameter D3 of the winding portion 93a of the first driven pulley 93 is smaller than the diameter D4 of the winding portion 94a of the second driven pulley 94, the tension generated in the flexible cable 9a is small, and the rotating shaft The rotational speed Na of 17 is larger than the rotational speed Nd1 of the first drive pulley 91. For this reason, the first two-way clutch is locked, and the first drive pulley 91 is rotationally driven by the rotational torque of the rotating shaft 17. At this time, the torsion spring 25 provided on the first drive pulley 91 pulls the flexible cable 9 a in the winding direction around the first drive pulley 91. For this reason, the slackness of the flexible cable 9a is suppressed, and the tension of the flexible cable 9a is maintained. In this way, the lead-out amount of the flexible cable 9b by the second driven pulley 94 and the winding amount of the flexible cable 9a by the first driven pulley 93 when the rotating shaft 17 rotates counterclockwise. And the difference is compensated.

  As described above, the driving device 90 of the motion assisting device according to the present embodiment has the driven shaft from the rotary shaft 17 according to the rotation direction of the driven shaft 95 that supports the first driven pulley 93 and the second driven pulley 94. The rotation transmission ratio to 95 can be varied. For this reason, the drive device 90 can change the rotational speed and rotational torque of the joint portion of the motion assisting device according to the rotational direction of the driven shaft 95 even when the rotational shaft 17 is driven at the same rotational speed. . Therefore, when the driven shaft 95 is rotated in a certain rotational direction, it can be rotated at a low torque and a high speed, and when it is rotated in another rotational direction, it can be rotated at a high torque and a low speed. As a result, an actuator having a relatively small output can be used as the actuator 11 to be used, and the weight and cost can be reduced, and the energy efficiency can be improved.

  The drive device 90 according to the present embodiment may be combined with the configuration of the drive device according to the first embodiment, the first modified example, the second modified example, and the third modified example.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, as an application example of the driving device of the motion assisting device, the driving device that generates the rotational torque of the knee joint portion arranged corresponding to the user's knee joint has been exemplified. It is not limited to such an example. The drive device of the motion assisting device according to the present invention may be a drive device that generates rotational torque of other joint portions such as a waist joint portion arranged corresponding to the user's hip joint.

DESCRIPTION OF SYMBOLS 1 ... Drive pulley, 3 ... 1st drive pulley, 5 ... 2nd drive pulley, 9, 9a, 9b ... Flexible cable, 10 ... Drive apparatus, 11 ... -Actuator, 17 ... Rotating shaft, 21 ... First two-way clutch, 23 ... Second two-way clutch, 25 ... Torsion spring, 70 ... Drive device, 71 ... One-way clutch 75 ... Torsion springs, 100 ... Motion assist devices, 120 ... Active joints

Claims (11)

In the drive device that rotationally drives the joint portion provided in the motion assisting device that is attached to the human body and assists the motion of the human body,
A first drive pulley supported on a rotating shaft;
A second drive pulley supported by the rotating shaft;
An actuator for outputting power for rotating the rotating shaft;
Flexible power transmission members having both ends wound around the first drive pulley and the second drive pulley,
A driven pulley wound around an intermediate portion of the power transmission member;
A first clutch that switches between rotational driving and idling of the first driving pulley by rotational torque of the rotating shaft;
A second clutch that switches between rotational driving and idling of the second driving pulley by rotational torque of the rotating shaft,
A drive device for an operation assisting device, wherein a rotation transmission ratio from the rotation shaft to the driven pulley varies according to at least one of a rotation direction and a rotation phase of the driven pulley.   The diameter of the winding part which the said power transmission member winds in the said 1st drive pulley is larger than the diameter of the winding part which the said power transmission member in the said 2nd driving pulley winds. A driving device for the movement assist device.   The driving device for an operation assisting device according to claim 2, wherein the first clutch is a one-way clutch or a two-way clutch.   At least one of a radius of a winding portion around which the power transmission member in the first driving pulley is wound and a radius of a winding portion around which the power transmission member in the second driving pulley is wound vary depending on a rotation phase. The driving device of the operation assisting device according to claim 1.   2. The driving device of the motion assisting device according to claim 1, wherein when the output of the actuator is the same, a rotation speed of the first drive pulley and a rotation speed of the second drive pulley are different.   The driving device of the operation assisting device according to any one of claims 1 to 5, wherein the second clutch is a two-way clutch.   The driving device of the operation assisting device according to any one of claims 1 to 6, wherein a radius of a winding portion around which the power transmission member is wound in the driven pulley varies depending on a rotation phase. In the drive device that rotationally drives the joint portion provided in the motion assisting device that is attached to the human body and assists the motion of the human body,
A first drive pulley supported on a rotating shaft;
A second drive pulley supported by the rotating shaft;
An actuator for outputting power for rotating the rotating shaft;
A driven pulley driven by a rotational torque of the first drive pulley and the second drive pulley;
Flexible first power transmission members having both ends wound around the first driving pulley and the driven pulley,
A flexible second power transmission member having both ends wound around the second driving pulley and the driven pulley, respectively;
A first clutch that switches between rotational driving and idling of the first driving pulley by rotational torque of the rotating shaft;
A second clutch that switches between rotational driving and idling of the second driving pulley by rotational torque of the rotating shaft,
A drive device for an operation assisting device, wherein a rotation transmission ratio from the rotation shaft to the driven pulley varies according to at least one of a rotation direction and a rotation phase of the driven pulley. In the drive device that rotationally drives the joint portion provided in the motion assisting device that is attached to the human body and assists the motion of the human body,
A first drive pulley supported on a rotating shaft;
A second drive pulley supported by the rotating shaft;
A first driven pulley supported by the driven shaft;
A second driven pulley supported by the driven shaft;
An actuator for outputting power for rotating the rotating shaft;
A flexible first power transmission member having both ends wound around the first driving pulley and the first driven pulley,
Flexible second power transmission members having both ends wound around the second driving pulley and the second driven pulley,
A first clutch that switches between rotational driving and idling of the first driving pulley by rotational torque of the rotating shaft;
A second clutch that switches between rotational driving and idling of the second driving pulley by rotational torque of the rotating shaft,
A driving device for an operation assisting device, wherein a rotation transmission ratio from the rotating shaft to the driven shaft differs according to at least one of a rotation direction and a rotation phase of the driven shaft.   The diameter of the winding portion around which the first power transmission member is wound in the first driven pulley is smaller than the diameter of the winding portion around which the second power transmission member is wound in the second driven pulley. The driving device of the operation assisting device according to claim 9. At least one of a radius of a winding portion around which the first power transmission member is wound in the first driven pulley and a radius of a winding portion around which the second power transmission member is wound in the second driven pulley. The driving device of the operation assisting device according to claim 9 or 10, wherein the frequency varies depending on the rotation phase.