JP2017124034A - Swinging joint device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swinging joint device that accumulates energy according to a swinging angle of a swinging motion part that carries out a reciprocatively swinging motion in an elastic body, and discharges the accumulated energy to the swinging motion part, and to reduce the thickness of the swinging joint device in which apparent rigidity of the elastic body seen from the swinging motion part can be adjusted according to the swinging angle of the swinging motion part.SOLUTION: An assist device (a swinging joint device) includes an output link 20 (a swinging motion part) that carries out a reciprocatively swinging motion, a spiral spring 100 (an elastic body) for accumulating or discharging energy according to a swinging angle of the output link, rigidity varying means 50 having a drive motor 52 for varying apparent rigidity of the spiral spring seen from the output link, control means for adjusting the apparent rigidity of the spiral spring seen from the output link, and a speed reducer 30 interposed between the output link and the spiral spring. The speed reducer, the spiral spring, and the drive motor are arranged in parallel with each other.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an oscillating joint device that periodically oscillates.

  As an example of a device that controls a joint that performs a periodic swinging motion, for example, Patent Document 1 discloses a one-leg walking support machine that assists a person's walking. This one-leg type walking support device is attached to a waist attachment portion that is attached to a side portion of a user's waist, a thigh link portion that is disposed on a side portion of the user's thigh, and a lower leg portion of the user. And a lower leg link portion. The upper part of the thigh link part is connected to the waist attachment part so as to be swingable in the front-rear direction of the user, and assist torque is applied to the thigh link part between the waist attachment part and the thigh link part. A torque generating device is provided. Walking assist is performed by applying the assist torque of the torque generator to the thigh link portion. The torque generator is configured to apply an assist torque to the thigh link portion by the action of the compression spring, the cam, and the cam follower. The magnitude of the assist torque is determined by the amount of compression of the compression spring set in advance. It is determined based on (the spring force of the compression spring). The compression amount of the compression spring is manually set using a tool.

JP 2013-236741 A

  In the above-described one-leg type walking support machine, since the compression amount of the compression spring is manually set using a tool, it is possible to change the compression amount according to the swing angle of the thigh link part during walking. Have difficulty. For this reason, it is difficult to change the assist torque in real time according to the swing angle of the thigh link part and perform walking assist with high efficiency.

  Therefore, a swing joint device 300 having the configuration shown in FIG. 11 is conceivable. The rocking joint device 300 includes a rocking motion unit 310, a speed reducer 320, a mainspring spring 330, and a drive motor 340. The swing motion unit 310 is attached to, for example, the side of the thigh 350 of the user 400 and reciprocally swings according to the user 400 walking. The energy of the oscillating motion of the oscillating motion unit 310 is once input to the mainspring spring 330 via the speed reducer 320, and the energy is re-released from the mainspring spring 330 to the oscillating motion unit 310, and the user 400 walks. Assist. The speed reducer 320 amplifies the torque output from the mainspring spring 330 and inputs the amplified torque to the swing motion unit 310. The drive motor 340 rotationally displaces one end of the spring spring 330 with respect to the other end in accordance with the swing angle of the swing motion unit 310, and the apparent rigidity of the spring spring 330 viewed from the swing motion unit 310 (spring spring). Change the spring force. Accordingly, the torque output from the mainspring spring 330 to the swing motion unit 310 is adjusted in real time according to the swing angle of the swing motion unit 310.

  In the oscillating joint device 300, the speed reducer 320, the mainspring spring 330, and the drive motor 340 are coaxially arranged toward the side of the waist 360 of the user 400. This coaxial arrangement simplifies the connection configuration between the members. However, when the speed reducer 320, the mainspring 330, and the drive motor 340 are arranged coaxially, the swing joint device 300 becomes thicker toward the side of the waist of the user 400. For this reason, the upper limb (not shown) of the user 400 may collide with the swing joint device 300, which is not preferable.

  An object of the present invention is an oscillating joint device that accumulates energy according to the oscillating angle of an oscillating motion part that reciprocally oscillates in an elastic body, and releases the accumulated energy to the oscillating motion part, and Another object of the present invention is to reduce the thickness of the swing joint device in the swing joint device capable of adjusting the apparent rigidity of the elastic body viewed from the swing motion portion according to the swing angle of the swing motion portion.

  In order to solve the above problems, the present invention takes the following means.

  The first aspect of the present invention is an energy storage mode in which energy is stored in an elastic body by movement of the moving body, connected to a moving body that reciprocally swings, and the moving body that releases energy stored in the elastic body An oscillating joint device that alternately repeats an energy release mode that supports the movement of the oscillating device, wherein the oscillating motion unit oscillates about the oscillating center that is the center of the reciprocating oscillating motion, and the oscillating motion unit An elastic body that accumulates or releases energy according to a moving angle, a stiffness variable means that has a drive motor and that makes the apparent rigidity of the elastic body viewed from the rocking motion section, and a rocking motion section The angle detection means for detecting the swing angle of the elastic member and the stiffness varying means are controlled in accordance with the swing angle detected by the angle detection means to adjust the apparent rigidity of the elastic body as viewed from the swing motion part. Control means and swing Deceleration that is interposed between the moving part and the elastic body, converts the input rotation amount input from one of the swinging motion part and the elastic body into an output rotation amount based on a predetermined conversion ratio, and outputs it to the other And have a machine. At least two of the speed reducer, the elastic body, and the drive motor are arranged in parallel without being arranged so as to be all coaxial.

  A second invention of the present invention is the swing joint device according to the first invention, wherein the elastic body is a spring. The apparent rigidity of the elastic body viewed from the swinging motion part is an apparent spring constant of the spring spring viewed from the swinging motion part.

  A third aspect of the present invention is the swing joint apparatus according to the second aspect, wherein the speed reducer has two input / output shafts rotating coaxially and is input to one input / output shaft. The input rotation amount is converted into an output rotation amount based on the conversion ratio and output from the other input / output shaft. The stiffness variable means is connected to one end of the mainspring and has a first power transmission means when the drive motor is arranged in parallel with the mainspring. The other end of the spring spring and one input / output shaft of the speed reducer are connected directly or via a second power transmission means. The other input / output shaft of the speed reducer and the oscillating motion part are connected directly or via third power transmission means. The reduction gear conversion ratio is set so that the rotation amount of the other input / output shaft on the side of the oscillating motion part decreases with respect to the rotation amount of one input / output shaft on the other end side of the spring. Has been.

  According to a fourth aspect of the present invention, there is provided the swing joint apparatus according to the third aspect, wherein the stiffness varying means rotates the one end of the mainspring spring around a spring center axis that is the central axis of the mainspring. And a drive motor that rotates the stiffness adjusting member coaxially with the mainspring via the first power transmission means. The first power transmission means is connected to the output shaft of the drive motor and rotates coaxially with the output shaft, and has a larger diameter than the first stiffness variable pulley and the first stiffness variable. A pulley is connected to the belt, and is connected to a stiffness adjusting member, and has a second stiffness variable pulley that rotates the stiffness adjusting member coaxially with the spring.

  According to a fifth aspect of the present invention, there is provided the swing joint device according to the fourth aspect, wherein the stiffness adjusting member rotates integrally with the adjusting portion main body rotating coaxially with the mainspring and the adjusting portion main body. An outer end connecting portion and a plurality of diameter expansion restricting portions. The outer end connection portion extends in parallel with the spring center axis and is connected to an outer peripheral end portion of the mainspring spring which is one end of the mainspring spring. Each of the diameter expansion restricting portions extends in parallel with the spring center axis around the outer periphery of the spring.

  A sixth invention of the present invention is the swing joint device according to the fifth invention, wherein each of the diameter expansion restricting portions is disposed on the opposite side of the outer end connecting portion across the spring center axis. Yes.

  A seventh invention of the present invention is the swing joint device according to the fifth or sixth invention, wherein each of the diameter expansion restricting portions is configured in a shaft shape, and each of the diameter expansion restricting devices. Each part is provided with a roller that is rotatable about the axis of each diameter expansion restricting part.

  In the configuration of the first invention, the control means changes the apparent rigidity of the elastic body viewed from the rocking motion unit according to the rocking angle of the rocking motion unit, so that the rocking motion from the elastic body. The energy output to the unit is adjusted in real time, and the reciprocating rocking motion of the moving body is assisted with high efficiency. In the configuration of the first invention, since at least two of the speed reducer, the elastic body, and the drive motor are arranged in parallel, the bulk of the member in one direction is suppressed, and the swing joint device is thin. It becomes.

  In the configuration of the second invention, the elastic body is a spring. As is well known, the spring spring is reduced in diameter or expanded in accordance with rotational displacement in both forward and reverse directions with respect to the other end of one end and accumulates elastic energy. Therefore, unlike the case of using a spring that can store elastic energy only by a displacement operation in one direction of extension, such as a coil spring, the swing joint device decelerates along with the reciprocating swing motion of the swing motion unit. Elastic energy can be stored in response to rotational movement in both forward and reverse directions input from the machine. Further, as described above, the spring spring accumulates elastic energy according to the rotational displacement. Therefore, unlike the case of using a spring that accumulates elastic energy in accordance with the linear displacement, such as a coil spring, the swing joint device changes the linear motion to a rotational motion in the connection mechanism between the spring spring and the speed reducer. A mechanism is unnecessary, and the connection mechanism can be easily configured. Therefore, the swing joint device is reduced in size.

  In the configuration of the third aspect of the invention, since the speed reducer is interposed between the swinging motion part and the spring spring, the torque output from the spring spring is amplified and input to the swinging motion part. Therefore, a relatively small spring having a small spring constant can be employed, and the load applied to the member that supports the spring when the spring is rotationally displaced is reduced. Therefore, the mainspring can be downsized, the number of members supporting the mainspring can be reduced, and the swing joint device can be downsized.

  In the fourth aspect of the invention, since the diameter of the second rigid pulley is larger than the diameter of the first variable stiffness pulley, the torque output from the drive motor is amplified and transmitted to the rigidity adjusting member and input to the spring. Is done. Therefore, the torque of the drive motor can be reduced, the drive motor can be reduced in size, and the current consumption of the drive motor is reduced.

  In the configuration of the fifth invention, the rigidity adjusting portion has a plurality of diameter expansion restricting portions extending in parallel with the spring center axis around the outer periphery of the mainspring spring. Each diameter expansion restricting part comes into contact with the outer periphery of the mainspring spring and restricts the expansion of the mainspring spring when the mainspring spring is in an expanded state. Therefore, the mainspring is deformed within a predetermined range. Therefore, in the swing joint device, a space to be secured for deformation of the mainspring can be set small, and the swing joint device is downsized.

  In the configuration of the sixth aspect of the invention, each of the diameter expansion restricting portions is disposed on the side opposite to the outer end connecting portion with the spring center axis interposed therebetween. When the spring spring is in a diameter-expanded state, a portion on the opposite side of the end portion on the outer peripheral side with respect to the center axis of the spring spreads radially outward. Therefore, each of the diameter expansion restricting portions is disposed on the side opposite to the outer end connecting portion with the spring center axis interposed therebetween, thereby restricting the spring spring from expanding radially outward.

  In the configuration of the seventh invention, a roller is mounted around each diameter expansion restricting portion. Therefore, each diameter expansion restricting portion regulates the spread of the spring spring while contacting the outer periphery of the spring spring with the roller and smoothly guiding the outer periphery in the circumferential direction.

It is a perspective view showing the state where the assist device is worn by the user. It is the perspective view which looked at the rigidity variable unit from the outward surface side of a base member. It is the perspective view which looked at the rigidity variable unit from the inward surface side of a base member. It is the perspective view which represented the rigidity variable unit in the decomposition | disassembly state. It is a perspective view of a rigidity adjustment member. It is a front view of a rigidity adjustment member. It is a front view of an output link. It is a front view of the mainspring in a free state. It is a front view of a mainspring spring showing the state where the inner end was rotated from the free state. It is a front view of a mainspring spring showing the state where the inner end and the outer end were relatively rotated from the free state. It is a front view of the conventional rocking | fluctuation joint apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The assist device 1 shown in FIG. 1 is an example of a swing joint device. The assist device 1 assists an operation such as walking or walking of a person. In addition, the X direction, the Y direction, and the Z direction shown in each figure correspond to the front direction, the left direction, and the upward direction of the user U wearing the assist device 1.

  As shown in FIG. 1, the assist device 1 includes a control box 3 and a variable stiffness unit 10. The control box 3 is attached to a first mounting tool 5 that is mounted around the waist U1 of the user U. The control box 3 is arranged at the center of the user U's waist U1. The control box 3 accommodates a control unit 9 that controls a drive motor 52, which will be described later, and a battery (not shown) that supplies power to the control unit 9 and the drive motor 52.

  As shown in FIG. 1, the variable stiffness unit 10 is attached to a second mounting tool 6 that is mounted around the waist U1 of the user U. The stiffness variable unit 10 is disposed on the side of the user U's waist U1 on the left leg side of the user U. The variable stiffness unit 10 includes a plate-like base member 11. The base member 11 has one surface facing the user U and the other surface facing the outside with respect to the user U. Hereinafter, in the base member 11, a surface facing the user U is referred to as an inward surface 11 a (see FIG. 3), and a surface facing outward from the user U is referred to as an outward surface 11 b (see FIGS. 1 and 2). The base member 11 has a mounting projection 19 at the top. The mounting convex portion 19 has a through hole 19a (see FIG. 4) penetrating in the front-rear direction. The second mounting tool 6 is inserted through the through hole 19a. The both surfaces 11a and 11b of the base member 11 are covered with a cover (not shown).

  As shown in FIG. 1, the variable stiffness unit 10 has an output link 20 (swinging motion unit). The output link 20 extends downward from the base member 11 and is disposed along the side of the user's U thigh U2 (moving body). The distal end portion of the output link 20 is a user mounting portion 20a that is folded upward. The user wearing part 20a sandwiches the third wearing tool 7 worn around the thigh U2 of the user U. As a result, the output link 20 is attached to the thigh U2 of the user U. The output link 20 reciprocally swings in the back-and-forth direction of the user U around a swing center axis P1 (see FIG. 4), which will be described later, according to the reciprocal swing motion of the thigh U2.

  As shown in FIGS. 2 and 4, the base member 11 includes the output link 20, the speed reducer 30, the input / output side power transmission unit 40 (second power transmission unit), the spring spring 100 (elastic body), and the stiffness variable unit 50. Etc. The stiffness variable means 50 includes a drive motor 52, a stiffness adjustment power transmission means 53 (first power transmission means), and a stiffness adjustment member 80. The reduction gear 30, the mainspring 100, and the drive motor 52 are arranged in parallel without being arranged coaxially. That is, both the input / output shafts 32 and 34 of the speed reducer 30, the spring center axis P <b> 2 that is the center axis of the mainspring 100, and the motor output shaft 52 a that is the output shaft of the drive motor 52 are positioned parallel to each other. There is a relationship. Both the input / output shafts 32, 34, the spring center axis P2, and the motor output shaft 52a extend in the thickness direction of the base member 11 (the side of the waist relative to the user). The speed reducer 30 is located below the drive motor 52. The mainspring 100 is located behind the speed reducer 30 and the drive motor 52.

  As shown in FIGS. 3 and 4, the output link 20 has a connection portion 20 b at the end opposite to the attachment portion 20 a. The connecting portion 20 b is disposed on the inward surface 11 a side of the base member 11. In detail, the connection part 20b is arrange | positioned at the link accommodation recessed part 13 in which the inward surface 11a was dented in the thickness direction. The connecting portion 20 b is directly connected to the first input / output shaft 32 (see later) of the speed reducer 30 by, for example, a bolt B and is not rotatable relative to the first input / output shaft 32. The output link 20 reciprocally swings (rotates) with the first input / output shaft 32 around the axis of the first input / output shaft 32. In FIG. 4, a unified symbol P <b> 1 is attached to the axis of the first input / output shaft 32 and the swing center axis of the output link 20. The swing center axis P1 extends to the side of the user's waist at a position corresponding to the user's hip joint. The bolt B1 connects the output link 20 to the first input / output shaft 32 on the swing center axis P1. A rotating part of an encoder 130 (angle detection means) is attached to the bolt B1, and a fixed part of the encoder 130 is attached to the base member 11 (not shown). The encoder 130 detects the swing angle of the output link.

  As shown in FIG. 4, the speed reducer 30 includes a first input / output shaft 32 and a second input / output shaft 34 that are coaxially held, and a rectangular fixed portion formed around the first input / output shaft 32. 36. The fixing portion 36 is fixed to the reduction gear housing portion 14 provided in the base member 11. The speed reducer accommodating portion 14 is a through hole in which the base member 11 is penetrated in the thickness direction in a shape corresponding to the fixed portion 36, and is provided at a position facing the link accommodating recess 13. The first input / output shaft 32 is disposed over both surfaces 11 a and 11 b of the base member 11, and the second input / output shaft 34 is disposed on the outward surface 11 b side of the base member 11.

  The speed reducer 30 converts an input rotation amount input to one of the input / output shafts 32 and 34 into an output rotation amount based on a predetermined conversion ratio n and outputs the output rotation amount from the other. The first input / output shaft 32 is decelerated and rotated with respect to the second input / output shaft 34 based on the conversion ratio n. The second input / output shaft rotates n (n> 1) with respect to one rotation of the first input / output shaft 32. As described above, the first input / output shaft 32 is connected to the output link 20. As will be described later, the second input / output shaft 34 is connected to the inner end 102 (see later) of the mainspring 100 via the input / output side power transmission means 40. Therefore, the speed reducer 30 is interposed between the output link 20 and the mainspring 100, and the output rotation amount input from one of the output link 20 and the inner end 102 of the mainspring 100 is output based on the conversion ratio n. Convert to quantity and output to the other.

  As shown in FIGS. 2 and 4, the input / output side power transmission means 40 includes a speed reducer side pulley 42, a spring side pulley 44, and a belt 46 that connects both pulleys. Both pulleys 42 and 44 have the same diameter. Both pulleys 42 and 44 are disposed on the outward face 11 b side of the base member 11. The reduction gear side pulley 42 is attached to the second input / output shaft 34 so as not to rotate relative to the second input / output shaft 34, and rotates coaxially with the second input / output shaft 34.

  As shown in FIGS. 2 and 4, the spring-side pulley 44 is provided to face the mainspring spring 100, and is provided on the side opposite to the base member 11 with respect to the mainspring spring 100. A support shaft 110 passes through the shaft center of the spring-side pulley 44. The support shaft 110 is held coaxially with the spring center axis P2 by a stiffness adjusting member 80 described later. The spring-side pulley 44 is supported by the support shaft 110 so as to be rotatable coaxially with the spring center axis P2. The spring-side pulley 44 has a shaft-shaped inner end support portion 44 a on the surface on the side facing the mainspring spring 100. The inner end support portion 44 a extends toward the mainspring spring 100 at a position away from the axis of the spring-side pulley 44 in the radial direction. The inner end support portion 44a is fitted into the inner end 102 of the spring 100 and rotates the inner end 102 about the spring center axis P2 (see FIGS. 8 and 9).

  As shown in FIGS. 2 and 4, the mainspring 100 is disposed on the outward face 11 b side of the base member 11. The mainspring 100 is a spring formed by spirally forming a leaf spring. The inner end 102 (end portion on the inner peripheral side) and the outer end 104 (end portion on the outer peripheral side) of the mainspring 100 are each wound in a hole shape penetrating in the direction of the spring center axis P2. As described above, the inner end 102 is fitted with the inner end support portion 44 a of the spring-side pulley 44. The outer end 104 is fitted with an outer end connecting portion 92 b (see below) of the rigidity adjusting member 80. By supporting the inner end 102 and the outer end 104, the spring center axis P <b> 2 of the mainspring spring 100 is held at a fixed position. The support shaft 110 described above is not in contact with the mainspring 100.

  The mainspring 100 has a reduced diameter state in which the inner end 102 and the outer end 104 are rotated in opposite directions around the spring center axis P2 so as to shrink from the free state shown in FIG. The elastic energy is stored by deforming from a free state to a radially expanded state (see FIGS. 9 and 10) that expands radially outward. Note that elastic energy is not stored in the mainspring 100 in the free state. The inner end 102 rotates according to the swing motion of the output link 20. The outer end 104 rotates according to the rotation of a motor output shaft 52a described later. The motor output shaft 52a is connected to the outer end 104 via a stiffness adjusting power transmission means 53 and a stiffness adjusting member 80 described later. When the outer end 104 is rotated with respect to the inner end 102, the apparent rigidity (spring force of the mainspring spring) of the mainspring 100 viewed from the output link 20 is changed. The apparent rigidity of the mainspring 100 viewed from the output link 20 is an apparent spring constant of the mainspring 100 viewed from the output link 20. The state of rotation of the spring 100 will be described in detail later with reference to FIGS.

  The rigidity adjusting member 80 is disposed on the base member 11 side with respect to the mainspring spring 100 as shown in FIGS. The stiffness adjusting member 80 includes an adjusting portion main body 82, a connecting overhang portion 92 and a restriction overhang portion 94 that are provided integrally with the adjusting portion main body 82. The adjusting portion main body 82 includes a large cylindrical portion 84 and a small cylindrical portion 86 provided in a stepped shape, and an adjusting disk portion 90 provided coaxially with both the cylindrical portions 84 and 86 and continuing to the small cylindrical portion 86. Have. The large cylindrical portion 84 is disposed in the adjustment member accommodating portion 16 provided in the base member 11. The adjustment member accommodating portion 16 is a circular through hole through which the base member 11 is penetrated in the thickness direction. For example, a slide bearing 70 is fixed to the adjustment member accommodating portion 16. The slide bearing 70 supports the large cylindrical portion 84 in a rotatable manner. The large cylindrical portion 84 cannot be retracted from the slide bearing 70 in the axial direction. The small cylindrical portion 86 is disposed so as to protrude from the base member 11 toward the outward surface 11b. The adjustment disk part 90 faces the mainspring 100. A support shaft 110 is passed through the axis of the adjustment unit main body 82. The adjustment unit main body 82 holds the support shaft 110 coaxially with the spring center axis P2. The adjustment unit main body 82 rotates around the support shaft 110 coaxially with the spring center axis P2. It should be noted that the connecting overhanging portion 92 and the regulating overhanging portion 94, which will be described later, rotate integrally with the adjusting portion main body 82.

  As shown in FIG. 5, the adjustment disk portion 90 includes a connection overhang portion 92 and a restriction overhang portion 94 that protrude from the outer peripheral surface thereof. The restriction overhangs 94 are provided at three locations. Each of the restriction overhang portions 94 will be described separately as a first restriction overhang portion 94A, a second restriction overhang portion 94B, and a third restriction overhang portion 94C. The configurations of the restricting overhanging portions 94A, 94B, and 94C are the same. As shown in FIG. 6, the restriction overhanging portions 94 </ b> A, 94 </ b> B, 94 </ b> C are provided on the opposite side of the connection overhanging portion 92 with the axis P <b> 3 of the stiffness adjusting member 80 interposed therebetween. Specifically, each of the restricting projecting portions 94A, 94B, 94C sandwiches a virtual straight line W that is orthogonal to the axis P3 of the stiffness adjusting member 80 and orthogonal to the projecting direction of the connecting projecting portion 92. And provided on the opposite side to the connecting overhang 92. The second restricting overhanging portion 94 </ b> B has a symmetrical positional relationship with the connecting overhanging portion 92. The first restriction overhang 94A and the third restriction overhang 94C are provided, for example, at a position 60 degrees away from the second restriction overhang 94B in the circumferential direction. The axis P3 of the stiffness adjusting member 80 coincides with the spring center axis P2.

  As shown in FIG. 5, the connecting overhang portion 92 includes a connecting extension portion 92a and an outer end connecting portion 92b. The connecting extension 92 a protrudes in the radial direction from the outer peripheral surface of the adjustment disk 90. The outer end connection portion 92b is a shaft-like portion that protrudes from the connection extension portion 92a toward the mainspring spring 100, and extends parallel to the spring center axis P2. The outer end connecting portion 92b is fitted into the outer end 104 of the spring 100 and rotates the outer end 104 around the spring center axis P2 (see FIGS. 9 and 10).

  As shown in FIG. 5, the restriction overhanging portion 94 includes a restriction extension portion 96 and a diameter expansion restriction portion 98. The restricting extension portion 96 protrudes in the radial direction from the outer peripheral surface of the adjustment disk portion 90. The distal end of the restriction extension 96 is located radially outward from the outer peripheral surface of the mainspring spring 100. The diameter expansion restricting portion 98 is a shaft-like portion that protrudes from the tip of the restricting extension portion 96 toward the mainspring spring 100 and extends in parallel with the spring center axis P2. The diameter expansion restricting portion 98 is disposed around the outer periphery of the mainspring spring 100. As shown in FIG. 10, the diameter-enlargement restricting portion 98 is in contact with the outer peripheral surface of the mainspring spring 100 in the diameter-enlarged state, and functions to restrict the outward expansion of the mainspring spring 100 in the radial direction. A roller R that is rotatable about the axis of the diameter expansion restricting portion 98 is attached to the diameter expansion restricting portion 98. The roller R smoothly guides the outer peripheral surface of the mainspring spring 100 in the expanded state in the circumferential direction.

  As shown in FIG. 4, the drive motor 52 is fixed to the motor housing portion 18 provided in the base member 11. The motor housing portion 18 is a through hole in which the base member 11 is penetrated in the thickness direction in a shape corresponding to the drive motor 52. The motor output shaft 52 a protrudes toward the inward surface 11 a of the base member 11. The motor output shaft 52a rotates in both forward and reverse directions. The rotation of the motor output shaft 52a is controlled by the control means 9. The rotation of the motor output shaft 52a rotates and drives the stiffness adjusting member 80 via the stiffness adjusting power transmission means 53 described later, and rotates the outer end 104 of the spring 100. In addition, an encoder (not shown) is attached to the drive motor 52.

  As shown in FIGS. 3 and 4, the stiffness adjusting power transmission means 53 includes a first stiffness variable pulley 54, a second stiffness variable pulley 56, and a belt 58 that connects both stiffness variable pulleys 54, 56. The first variable stiffness pulley 54 is disposed on the inward surface 11 a side of the base member 11 and faces the drive motor 52. The first variable stiffness pulley 54 is attached to the motor output shaft 52a so as not to be relatively rotatable, and rotates coaxially with the motor output shaft 52a.

  The second variable stiffness pulley 56 is disposed on the inward surface 11 a side of the base member 11 and faces the stiffness adjusting member 80. The support shaft 110 is penetrated through the shaft center of the second variable stiffness pulley 56. The second variable stiffness pulley 56 is supported by the support shaft 110 so as to be coaxial and rotatable with the stiffness adjusting member 80. The second variable stiffness pulley 56 has a shaft-like connecting portion 56 a on the surface facing the stiffness adjusting member 80. The connecting portion 56a extends toward the stiffness adjusting member 80 at a position away from the axial center of the second stiffness variable pulley 56 in the radial direction. The connecting portion 56 a is fitted into a connecting hole 84 a provided in the large cylindrical portion 84 of the rigidity adjusting member 80. The connecting portion 56a rotates the stiffness adjusting member 80 around the support shaft 110.

  The second stiffness variable pulley 56 has a larger diameter than the first stiffness variable pulley 54. Therefore, the torque of the drive motor 52 is amplified and transmitted to the stiffness adjusting member 80 and input to the mainspring 100. Accordingly, the torque of the drive motor 52 may be small, the drive motor 52 can be reduced in size, and current consumption of the drive motor 52 can be suppressed.

  The operation of the assist device 1 will be described. The reciprocating rocking motion of the output link 20 accompanying the walking of the user U is input to the mainspring 100 via the speed reducer 30 and the input / output side power transmission means 40 and rotates the inner end 102 of the mainspring spring 100. The state of this rotation will be described later with reference to FIGS. When the inner end 102 rotates, elastic energy corresponding to the swing angle of the output link 20 is accumulated in the mainspring spring 100. Thereafter, the mainspring 100 rotates in the return direction so as to eliminate the rotational displacement of the inner end 102, thereby releasing the elastic energy accumulated therein toward the output link 20. The rotation of the spring 100 in the return direction is output to the output link 20 via the speed reducer 30 and the input / output side power transmission means 40, and the output link 20 is swung. This swing assists the user U's walking (the swing motion of the user's U thigh U2). As described above, in the assist device 1, the energy storage mode in which the elastic energy is stored in the mainspring spring 100 according to the reciprocating swing motion of the user U's thigh U <b> 2 and the elastic energy stored in the mainspring spring 100 are released to release the user U The energy release mode that supports the reciprocating rocking motion of the thigh U2 is alternately repeated. The control means 9 changes the apparent rigidity of the mainspring 100 viewed from the output link 20 in real time according to the swing angle of the output link 20. That is, the control unit 9 rotates the motor output shaft 52 a according to the swing angle of the output link 20 detected by the encoder 130. The rotation of the motor output shaft 52a rotates the stiffness adjusting member 80 via the stiffness adjusting power transmission means 53 and rotates the outer end 104 of the mainspring spring 100. As a result, the apparent rigidity of the mainspring 100 viewed from the output link 20 is changed. The state of rotation of the outer end 104 will be described later with reference to FIGS. The control means 9 changes the apparent rigidity of the spring 100 so that the user's own driving energy required for the reciprocating swinging motion of the user's U thigh U2 is always minimized.

  A state of rotational displacement of the mainspring 100 accompanying the reciprocating swinging motion of the output link 20 will be described. FIG. 7 shows how the output link 20 reciprocally swings. When the output link 20 is in the swing reference position indicated by the solid line in FIG. 7, the mainspring 100 is in the free state shown in FIG. A reference line FF shown in FIG. 8 is an imaginary straight line passing through the spring center axis P2 and the inner end 102, and indicates the reference position of the inner end 102. The reference line FF is a virtual straight line passing through the spring center axis P2 and the outer end 104, and indicates the reference position of the outer end 104. 8 to 10 schematically show only the diameter expansion restricting portion 98 and the outer end connecting portion 92b with respect to the stiffness adjusting member 80.

  The dotted line in FIG. 7 shows a state in which the output link 20 is swung in the clockwise direction (forward) from the swing reference position by the swing angle θ. In response to the swinging of the output link 20, the inner end 102 of the spring 100 is rotated clockwise from the reference position by the rotation angle n · θ, as shown in FIG. As already explained, n is the conversion ratio of the reduction gear 30. In FIG. 9, the drive motor 52 is not driven and the outer end 104 is at the reference position. In the state shown in FIG. 9, torque corresponding to the rotation angle n · θ acts counterclockwise on the inner end 102. This torque oscillates the output link 20 in the counterclockwise direction (backward) to assist the user's walking. When the inner end 102 of the spring 100 rotates counterclockwise in response to the swing of the output link 20, a clockwise torque acts on the inner end 102, and the output link 20 moves in the clockwise direction (frontward). ).

  FIG. 10 shows a state in which the drive motor 52 is driven and the outer end 104 is rotated counterclockwise from the reference position by the rotation angle θ1 with respect to the state shown in FIG. In the state shown in FIG. 10, the torque corresponding to the sum of the rotation angle n · θ and the rotation angle θ1 acts on the inner end 102 in the counterclockwise direction. This torque is output to the output link 20 to assist the user's walking. In the state shown in FIG. 10, the outer end 104 is rotationally displaced with respect to the inner end 102, so that the apparent rigidity viewed from the output link 20 is changed with respect to the state shown in FIG. Therefore, in the state shown in FIG. 10, the elastic energy accumulated in the mainspring 100 is different from the state shown in FIG. When the outer end 104 rotates clockwise from the reference position by the rotation angle θ1 with respect to the state shown in FIG. 9, the inner end 102 is reduced by the rotation angle θ1 from the rotation angle n · θ. Torque works.

  As shown in FIG. 10, each diameter expansion restricting portion 98 comes into contact with the outer peripheral surface of the mainspring spring 100 in the diameter expanded state, and restricts the outward expansion of the mainspring spring 100 in the radial direction. Therefore, deformation of the mainspring 100 is kept within a predetermined range. Therefore, in the variable stiffness unit 10, the space secured for deformation of the mainspring 100 can be set small. Therefore, the variable stiffness unit 10 is reduced in size.

  As shown in FIG. 10, each diameter expansion restricting portion 98 is disposed on the opposite side to the outer end connecting portion 92b with the spring center axis P2 interposed therebetween. As shown in FIG. 10, when the mainspring 100 is in a diameter-expanded state, a portion on the opposite side of the outer end 104 spreads radially outward across the spring center axis P2. Accordingly, each of the diameter expansion restricting portions 98 is disposed on the opposite side of the outer end connecting portion 92b with the spring center axis P2 interposed therebetween, thereby reliably restricting the spring spring 100 from spreading outward in the radial direction. .

  Each diameter expansion restricting portion 98 is equipped with a roller R. Therefore, each diameter expansion restricting portion 98 regulates the spread of the spring spring 100 while contacting the outer peripheral surface of the mainspring spring 100 with the roller R and smoothly guiding the outer peripheral surface in the circumferential direction.

  The assist device 1 is configured as described above. In the above-described configuration, the control means 9 changes the apparent stiffness of the mainspring 100 viewed from the output link 20 in real time according to the swing angle of the output link 20, so that the output is output from the mainspring 100 to the output link 20. The energy to be adjusted is adjusted in real time, and the reciprocating swing motion of the thigh U2 of the user U is assisted with high efficiency.

  In the above-described configuration, the speed reducer 30, the spring 100, and the drive motor 52 are arranged in parallel with respect to the base member 11 that faces the side of the waist U1 of the user U (see FIG. 1). Therefore, the bulkiness of the member directed to the side of the waist U1 of the user U is suppressed, and the variable stiffness unit 10 is thinned laterally from the waist U1 of the user U.

  In the above-described configuration, the mainspring 100 is employed as the elastic body. The spring 100 is reduced in diameter or expanded in accordance with rotational displacement in both forward and reverse directions with respect to the outer end 104 of the inner end 102 and accumulates elastic energy. Therefore, in the variable stiffness unit 10, unlike the case where a spring that can store elastic energy only by a displacement operation in one direction of extension, such as a coil spring, is used, the speed reducer accompanies the reciprocating swing motion of the output link 20. Elastic energy can be stored in response to the rotational movement in both forward and reverse directions input from 30. Further, the mainspring 100 accumulates elastic energy according to the rotational displacement as described above. Therefore, in the variable stiffness unit 10, unlike the case of using a spring that accumulates elastic energy according to a linear displacement, such as a coil spring, the linear operation is changed to a rotational operation in the connection mechanism between the mainspring spring 100 and the speed reducer 30. A mechanism for changing is unnecessary, and the connecting mechanism can be simply configured by the speed reducer side pulley 42, the spring side pulley 44, and the belt 46. Therefore, the variable stiffness unit 10 is reduced in size.

  In the above configuration, since the speed reducer 30 is interposed between the output link 20 and the spring spring 100, the torque output from the spring spring 100 is amplified and input to the output link 20. Therefore, the relatively small spring spring 100 having a small spring constant can be adopted, and the load applied to the member that supports the spring spring 100 when the spring spring 100 is rotationally displaced is reduced. Therefore, the mainspring 100 can be downsized, the number of members supporting the mainspring 100 can be reduced, and the variable stiffness unit 10 can be downsized.

  The embodiments for carrying out the present invention have been described above with reference to the drawings. However, the present invention is not limited to the structure, configuration, appearance, shape, and the like described in the above embodiments. Various changes, additions, and deletions are possible without departing from the scope of the present invention.

  The reduction gear 30, the mainspring 100, and the drive motor 52 may be configured such that only two of these three are arranged in parallel. For example, the reduction gear 30 and the mainspring 100 may be arranged coaxially, and the drive motor 52 may be arranged in parallel to the reduction gear 30 and the mainspring 100. In this case, the input / output side power transmission means 40 is eliminated, and the reduction gear 30 and the spring 100 can be directly connected.

  The drive motor 52 and the mainspring 100 may be arranged coaxially, and the speed reducer 30 may be arranged in parallel to the drive motor 52 and the mainspring 100. In this case, the rigidity adjusting power transmission means 53 is abolished. The drive motor 52 and the mainspring 100 are connected via a stiffness adjusting member 80.

  The drive motor 52 and the speed reducer 30 may be arranged coaxially, and only the mainspring 100 may be arranged in parallel with the drive motor 52 and the speed reducer 30. The speed reducer 30 and the output link 20 may be arranged in parallel, and the speed reducer 30 and the output link 20 may be connected via appropriate power transmission means (third power transmission means) instead of directly. . In this case, the input / output shafts 32 and 34 of the speed reducer 30 and the swing center axis of the output link 20 are in a parallel positional relationship.

  If each member which comprises the assist apparatus 1 functions similarly to the above-mentioned embodiment, a structure, a structure, an external appearance, a shape, etc. can be changed freely.

  The assist device may be arranged and used on the right leg side of the user U. The configuration of the assist device in this case is bilaterally symmetric with respect to the configuration shown in the above-described embodiment. The assist device may be attached to each of the left and right legs.

  The elastic body is not limited to the mainspring 100, and any elastic body can be used as long as it can alternately repeat the energy storage mode and the energy release mode.

  The number of diameter expansion restricting portions 98 is not limited to three and may be any number. The arrangement of the diameter expansion restricting portion 98 may be on the side opposite to the outer end connecting portion 92b across the virtual straight line W (spring central axis P2) shown in FIG. 6, and is limited to the arrangement shown in the above embodiment. It is not something.

  The swing joint device of the present invention is not limited to the assist device 1 described above, and may be any device as long as it controls a joint that performs a periodic swing motion.

1 Assist device (oscillating joint device)
9 Control means 20 Output link (oscillating motion part)
30 reducer 32 first input / output shaft 34 second input / output shaft 40 input / output side power transmission means (second power transmission means)
50 Stiffness variable means 52 Drive motor 52a Motor output shaft 53 Stiffness adjusting power transmission means (first power transmission means)
54 1st rigidity variable pulley 56 2nd rigidity variable pulley 80 Stiffness adjustment member 82 Adjustment part main body 92b Outer end connection part 98 Diameter expansion restriction part 100 Spring spring (elastic body)
102 Inner end 104 Outer end 130 Encoder (Angle detection means)
n Conversion ratio P2 Spring center axis R Roller

Claims (7)

Connected to a moving body that reciprocally oscillates, an energy storage mode in which energy is stored in the elastic body by the movement of the moving body, and the movement of the moving body is supported by releasing the energy stored in the elastic body. An oscillating joint device that alternately repeats the energy release mode,
An oscillating motion part that oscillates about an oscillation center that is the center of reciprocating oscillating movement;
The elastic body that accumulates the energy or releases the energy according to a rocking angle of the rocking motion unit;
A stiffness varying means having a drive motor and varying the apparent stiffness of the elastic body as seen from the rocking motion section;
Angle detecting means for detecting the swing angle;
Control means for controlling the stiffness variable means according to the swing angle detected by the angle detection means to adjust the apparent stiffness of the elastic body as seen from the swing motion part;
An input rotation amount that is interposed between the swinging motion unit and the elastic body and is input from one of the swinging motion unit and the elastic body is converted into an output rotation amount based on a predetermined conversion ratio. And a speed reducer that outputs to the other
Three of the speed reducer, the elastic body and the drive motor are arranged in parallel without being arranged so as to be all coaxial,
Swing joint device. The oscillating joint device according to claim 1,
The elastic body is a spring spring,
The apparent rigidity of the elastic body viewed from the swinging motion part is an apparent spring constant of the spring spring viewed from the swinging motion part.
Swing joint device. The swing joint device according to claim 2,
The speed reducer has two input / output shafts rotating on the same axis, and converts the input rotation amount input to one of the input / output shafts into the output rotation amount based on the conversion ratio. Output from the input / output shaft,
The rigidity varying means is connected to one end of the mainspring and has a first power transmission means when the drive motor is arranged in parallel with the mainspring.
The other end of the mainspring and the one input / output shaft of the speed reducer are connected directly or via a second power transmission means,
The other input / output shaft of the speed reducer and the swinging motion part are connected directly or via third power transmission means,
The conversion ratio of the speed reducer is such that the rotation amount of the other input / output shaft on the side of the oscillating motion part is relative to the rotation amount of the one input / output shaft on the other end side of the mainspring spring. Is set to decrease,
Swing joint device. The swing joint device according to claim 3,
The stiffness varying means is a stiffness adjusting member that rotates one end of the spring spring around a spring center axis that is a center axis of the spring.
The drive motor for rotating the rigidity adjusting member coaxially with the mainspring via the first power transmission means;
The first power transmission means is connected to an output shaft of the drive motor and rotates coaxially with the output shaft.
The diameter is larger than that of the first variable stiffness pulley, and the belt is connected to the first variable stiffness pulley and connected to the stiffness adjusting member, and the stiffness adjusting member is coaxial with the mainspring spring. A second variable stiffness pulley that rotates.
Swing joint device. The swing joint device according to claim 4,
The rigidity adjustment member includes an adjustment unit main body that rotates coaxially with the mainspring, an outer end connection unit that rotates integrally with the adjustment unit main body, and a plurality of diameter expansion restriction units,
The outer end connecting portion extends in parallel with the spring central axis and is connected to an outer peripheral end of the mainspring which is one end of the mainspring,
Each of the diameter expansion restricting portions extends in parallel with the spring center axis around the outer periphery of the mainspring spring.
Swing joint device. The swing joint device according to claim 5,
Each of the diameter expansion restricting portions is disposed on the opposite side to the outer end connecting portion with the spring center axis interposed therebetween.
Swing joint device. The swing joint device according to claim 5 or 6,
Each of the diameter expansion restricting portions is configured in a shaft shape,
Each of the diameter expansion restriction portions is equipped with a roller that is rotatable around the axis of each of the diameter expansion restriction portions.
Swing joint device.

Images