Assist device

Abstract

An assistance device 10 comprises: a first harness 11 worn at least on a shoulder portion BS of a user; second harnesses 12 worn on each of left and right leg portions BL of the user; a third harness 40 worn on a waist portion BW of the user; a belt body 13 provided along a back surface of the user, across the first harness 11 and the second harness 12; an actuator 14 which is provided on the first harness 11 and which enables a portion of the belt body 13 to be wound in and fed out; and a back portion frame 44 which links the first harness 11 and the third harness 40 in the center of the back surface of the user to retain a spacing thereof. An outside surface 44c of the back portion frame 44 that faces the side opposite to the user includes a first sliding contact surface 48 with which the belt body 13 comes into sliding contact.

Description

Technical Field

[0001] The present invention relates to an assist device.

Background Art

[0002] For example, Patent Document 1 discloses an assist device including a first wearable device worn on the back of a user, a second wearable device worn on the left and right legs of the user, a belt body provided along the back side of the user across the first wearable device and the second wearable device, and an actuator provided in the first wearable device. This assist device generates tension in the belt body by winding up a part of the belt body with the actuator. This tension acts as an assist force on the user.

[0003] Further, this assist device includes a support mechanism for supporting the user's body. This support mechanism is a mechanism for efficiently applying the tension of the belt body as an assist force to the user's waist. The support mechanism includes a waist wearable body fixed to the user's waist, a back wearable body included in the first wearable device, and a holding body that connects the waist wearable body and the back wearable body and maintains the distance between them. This holding body includes a pair of frames that connect the waist wearable body and the back wearable body on both the left and right sides of the user's body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The pair of frames of the above conventional assist device are arranged on both the left and right sides of the user's body. Therefore, the user's movement may be hindered because the user's arm interferes with the pair of frames or the user's movement is greatly restricted. (Note: There seems to be a typo in the original text where "[[ID=3?]]" should probably be "". This has been left as is in the translation to match the original.) [Means for solving the problem]

[0006] The assist device according to the embodiment comprises: a first attachment worn on at least the shoulders of the user; second attachments worn on each of the user's left and right legs; a third attachment worn on the user's waist; a belt body provided along the user's back, spanning the first and second attachments; an actuator provided on the first attachment enabling the winding and unwinding of a portion of the belt body; and a back frame connecting the first and third attachments in the center of the user's back and maintaining the distance between them. The first surface of the back frame facing away from the user includes a first sliding contact surface with which the belt body slides. [Effects of the Invention]

[0007] According to this disclosure, it is possible to suppress the disruption of user actions. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a rear view of the assist device according to the embodiment, showing it attached to the user's body. [Figure 2] Figure 2 is an explanatory diagram showing a user with an assist device attached in a forward-leaning posture. [Figure 3] Figure 3 is a magnified view of the main parts on the back of the assist device. [Figure 4] Figure 4 shows the moment acting on a user in a forward-leaning posture. [Figure 5] Figure 5 is an enlarged view of the main parts on the back of the assist device. [Figure 6] Figure 6 is a schematic diagram showing a cross-section of the retainer and protective member. [Figure 7] Figure 7 shows the second device, attached to the user's right leg, viewed from the rear. [Figure 8]Figure 8 shows the second device attached to the user's right leg, viewed from a diagonal front angle. [Figure 9] Figure 9 shows a holder according to another embodiment. [Figure 10] Figure 10 is a cross-sectional view taken along the line AA in Figure 9. [Figure 11] Figure 11 is a cross-sectional view taken along the line BB in Figure 9. [Modes for carrying out the invention]

[0009] First, the details of the embodiment will be listed and explained. [Summary of the Embodiment] (1) The assist device according to the embodiment comprises: a first attachment worn on at least the shoulders of the user; second attachments worn on each of the left and right legs of the user; a third attachment worn on the waist of the user; a belt body provided along the back of the user, spanning the first and second attachments; an actuator provided on the first attachment that enables winding and unwinding of a portion of the belt body; and a back frame that connects the first and third attachments in the center of the back of the user and maintains the distance between them. The first surface of the back frame facing away from the user includes a first sliding contact surface with which the belt body slides.

[0010] According to the above configuration, since there is a back frame connecting the first and third attachments, it is possible to maintain the distance between the first attachment worn on the back and the third attachment worn on the waist without having to place frames or other structures on both the left and right sides of the user's body. As a result, it is possible to suppress any obstruction to the user's movement. Furthermore, since the back frame has a first sliding contact surface on the first surface facing away from the user, it is possible to suppress the belt from sliding against parts other than the first sliding contact surface, such as the user's back. This prevents the belt from sliding against the user's back and hindering the movement of the belt.

[0011] (2) It is preferable that the assist device further includes a first guide for preventing the belt body from coming off the first sliding contact surface. In this case, even when the user bends forward while twisting the upper body left and right and the belt body tends to shift in the left - right direction, it is possible to prevent the belt body from coming off the first sliding contact surface. As a result, it is possible to prevent the belt body from coming off the back frame and sliding on a part other than the back frame, which may inhibit the movement of the belt body, or the extension direction of the belt body from deviating significantly from the winding direction of the actuator, and suppress the loss of the tension of the belt body that is the source of the assist force.

[0012] (3) Also, in the assist device, it is preferable that the first guide is a wall portion protruding from the first surface along both the left and right sides of the first sliding contact surface. In this case, the wall portion can prevent the belt body from coming off the first sliding contact surface.

[0013] (4) Also, in the assist device, it may further include a plate - shaped protection member provided on the leg portion side of the back frame, and a second surface facing the opposite side of the user in the protection member may include a second sliding contact surface with which the belt body slides. In this case, it is possible to suppress the movement of the belt body from being inhibited when the belt body slides on the buttocks or the like below the user's waist.

[0014] (5) Also, in the assist device, the protection member may include a second guide for preventing the belt body from coming off the second sliding contact surface. In this case, even when the user bends forward while twisting the upper body left and right and the belt body tends to shift in the left - right direction, it is possible to prevent the belt body from coming off the second sliding contact surface.

[0015] Also, in the assist device, it is conceivable to configure the second wearing device to be fixed to the knee by a belt or the like. However, if the second device is configured to be fixed to the knee, there is a risk that the second device may shift position due to the tension of the belt or significant changes in the user's posture. If the second device shifts position, it will reduce the tension of the belt that provides the assisting force, making it impossible to generate the assisting force efficiently.

[0016] (6) In contrast, the second attachment preferably comprises a pair of lower leg belts whose upper ends are connected to the belt body, a foot strap that connects the lower ends of the pair of lower leg belts and has a contact surface that comes into contact with the soles of the user's feet, and a retaining strap that is provided on the pair of lower leg belts and is attached to the user's knees. In this case, the foot strap of the second device is attached to the sole of the user's foot. Therefore, the tension from the belt acts to lift the sole of the user's foot, preventing the second device from shifting position.

[0017] (7) Preferably, the retaining band and the pair of lower leg belts are provided so as to be able to move relative to each other along the extension direction of the pair of lower leg belts. The combined length of the belt body, including the portion extending from the actuator and the second attachment, can be adjusted by the actuator. Therefore, by adjusting the position of the retaining strap to match the user's knee position, the second device can be properly fitted to users of various heights without having to adjust the length of the pair of lower leg belts.

[0018] [Details of the embodiment] Preferred embodiments will be described below with reference to the drawings. [Overall configuration of assist device 10] Figure 1 is a rear view of the assist device according to the embodiment, showing it attached to the user's body. Figure 2 is an explanatory diagram showing a user wearing the assist device in a forward-leaning posture (bent-over posture).

[0019] In the assist device 10 of this disclosure, left and right refer to the left and right relative to the user in an upright position wearing the assist device 10, front and back refer to the front and back relative to the user, and up and down refer to the up and down relative to the user. Up is the user's head side, and down is the user's leg side.

[0020] The assist device 10 of this embodiment comprises one first attachment 11, two second attachments 12, one third attachment 40, and a belt body 13. The first attachment device 11 is attached to the left and right shoulder BS of the user (person). The first attachment device 11 only needs to be attached to at least the shoulder BS of the user, and may be in a form other than that shown in the illustration. The second device 12 is attached to the left and right leg sections BL of the user. In this disclosure, the second device 12 is attached to the lower leg section BLL within the leg section BL. The left and right second devices 12 have the same configuration. The third attachment device 40 is attached to the user's lumbar region (BW).

[0021] The first attachment 11 includes a base 21, a pair of left and right shoulder straps 22, and a cushioning member 23. The base 21 includes a control box 30 that houses the control unit 15 and the like, which will be described later. The base 21 is carried on the user's back by a pair of shoulder straps 22. A pair of shoulder straps 22 are mounted on the top of the base 21 (control box 30). The ends 22a of each shoulder strap 22 are connected to the third attachment 40. The length of the shoulder straps 22 is adjustable. By adjusting the length of the shoulder straps 22, the base 21 is fixed to the user's back BB via the cushioning member 23.

[0022] The cushioning member 23 is interposed between the back BB and the control box 30 to prevent direct contact between the back BB and the control box 30. The cushioning member 23 is made of sponge or a structure with a mesh sheet attached to its surface. The structure is a cushioning member obtained by attaching a mesh sheet to a frame made by assembling spring wire into a predetermined three-dimensional shape.

[0023] The first attachment device 11 is fitted to the shoulder portion BS so as not to move in the forward / backward, left / right, and up / down directions. The first attachment device 11 may include, for example, a rigid material as the part that rests on the shoulder portion BS.

[0024] Each of the pair of second attachments 12 comprises a pair of lower leg belts 24, a foot strap 25, and a retaining strap 26. The pair of lower leg belts 24 are strip-shaped members made of a non-stretchable material. The pair of lower leg belts 24 are fitted along the lower leg BLL. The upper ends 24a of the pair of lower leg belt sections 24 are connected to a belt body 13 (described later) extending from the control box 30.

[0025] The foot strap 25 connects the lower ends 24b of a pair of lower leg belt sections 24. The user's feet BF are placed on the foot strap 25. The retaining strap 26 is a band-shaped member made of a flexible fabric or the like, and is provided on a pair of lower leg belt sections 24. The retaining strap 26 is attached to the knee section BN. In this way, the retaining strap 26 holds the pair of lower leg belt sections 24 at the knee section BN.

[0026] As described above, by attaching each part of the second attachment device 12 to the user's lower leg BLL, the second attachment device 12 is attached so that it does not move in the forward / backward, left / right, or up / down directions relative to the user's lower leg BLL. The second attachment device 12 will be described in detail later.

[0027] The third attachment device 40 is a band-shaped member made of a flexible fabric or the like. Both ends of the third attachment device 40 are provided with fastening members such as buckles or hook-and-loop fasteners (not shown). When the third attachment device 40 is wrapped around the waist BW, both ends of the third attachment device 40 are secured by the fastening members. This ensures that the third attachment device 40 does not move in the forward / backward, left / right, or up / down directions relative to the waist BW.

[0028] The third attachment 40 comprises a front belt portion 40a, a pair of rear belt portions 40b, and a pair of connecting portions 40c. The front belt portion 40a is the part of the third attachment device 40 that is located on the front side of the user when it is attached to the waist belt. The pair of rear belt sections 40b are the parts of the third attachment device 40 that are located on the rear side of the user when attached to the waist belt (BW). The pair of connecting sections 40c are the parts where the ends of the front belt section 40a and the ends of the pair of rear belt sections 40b are connected. The connecting sections 40c are located on the left and right sides of the waist section BW. The position of the connecting sections 40c is approximately coincident with the axis of rotation of the user's thigh.

[0029] The pair of rear belt sections 40b are positioned on the upper and lower sides of the waist belt. This prevents the third attachment 40 from shifting vertically relative to the waist belt when the user changes posture. A connecting member 40d is provided at the left and right connecting portion 40c. The connecting member 40d is a member for connecting the tip portions 22a of a pair of shoulder belts 22. In other words, the pair of shoulder straps 22 are connected to the connection point 40c of the third attachment device 40.

[0030] The belt body 13 is positioned along the user's back (back BB). The belt body 13 connects the first attachment device 11 and the second attachment device 12. The belt body 13 includes a first belt 16, a second belt 17, and a connecting member 18. The first belt 16 is provided on the upper body side of the user. The second belt 17 is provided on the lower body side of the user. The connecting member 18 connects the first belt 16 and the second belt 17. The first belt 16 and the second belt 17 are long and flexible. The connecting member 18, as will be described later, consists of a rectangular ring-shaped body, such as a "flat ring" or "square ring," and a fastener such as a buckle.

[0031] The first belt 16 and the second belt 17 are strip-shaped members made of cloth or leather, and are bendable to conform to the shape of the body. The first belt 16 and the second belt 17 may also be string-shaped belts (wire-like members). The first belt 16 and the second belt 17 in this disclosure are non-stretchable members. That is, the first belt 16 and the second belt 17 have the characteristic of being difficult or impossible to stretch in the longitudinal direction.

[0032] Figure 3 is an enlarged view of the main part of the rear of the assist device 10. In Figure 3, the control box 30 is shown in its interior. Also, in Figure 3, for ease of understanding, the control box 30 and its interior, as well as a part of the belt body 13 are shown, while other parts are omitted. In addition to the first attachment 11, second attachment 12, third attachment 40, and belt body 13 described above, the assist device 10 includes an actuator 14, a control unit 15, a battery 37, and a sensor 38. The actuator 14, control unit 15, battery 37, and sensor 38 are housed within a control box 30, which is a casing. The control box 30 has a back plate 31 and a cover 32 that covers the back plate 31. In Figure 3, the cover 32 is shown by a dashed line (two-dot dashed line). An opening (notch) 32a is provided at the lower end of the cover 32. The first belt 16 passes through the opening 32a.

[0033] The actuator 14 enables the winding and unwinding of a portion of the belt body 13. In other words, the actuator 14 expands and contracts the belt body 13 between the first mounting device 11 and the second mounting device 12. The actuator 14 includes a motor 33, a reduction gear 34, and a drive pulley 35. Motor 33 is a brushless DC motor. Motor 33 rotates at a predetermined torque and rotational speed based on control commands provided by the control unit 15. Motor 33 can also rotate in both forward and reverse directions based on control commands.

[0034] The rotation parameters of the motor 33, such as the rotation angle, rotation speed, or rotational speed, are detected by the rotation detector 36. The rotation detector 36 is provided on the motor 33. The rotation detector 36 in this disclosure is a rotary encoder, but it may also be a Hall sensor or a resolver. The output of the rotation detector 36 is provided to the control unit 15.

[0035] The reduction gear unit 34 is composed of multiple gears. The reduction gear unit 34 reduces the rotational speed of the motor 33 and rotates the output shaft 34a of the reduction gear unit 34. A drive pulley 35 is integrally connected to the output shaft 34a so as to be able to rotate together with it. One end 16a of the first belt 16 is fixed to the drive pulley 35. When the motor 33 rotates in the forward direction, the drive pulley 35 rotates in one direction, and the first belt 16 is wound onto the drive pulley 35. When the motor 33 rotates in the reverse direction, the drive pulley 35 rotates in the other direction, and the first belt 16 is fed out from the drive pulley 35. In this way, the actuator 14 can wind up and unwind the first belt 16, which is part of the belt body 13.

[0036] The control unit 15 is configured, for example, by a microcomputer. The control unit 15 has the function of controlling the actuator 14 based on the output of the rotation detector 36 and the output of the sensor 38. The processing performed by the control unit 15 will be described later.

[0037] The sensor 38 includes, for example, an acceleration sensor. The output of the sensor 38 is supplied to the control unit 15. The sensor 38 may consist of one sensor unit or multiple sensor units. Furthermore, the sensor 38 may be a tilt sensor, a gyroscope, or a combination thereof, in addition to an acceleration sensor. Furthermore, the sensor 38 may be located outside the control box 30. The battery 37 supplies power to various parts of the assist device, such as the control unit 15 and the motor 33.

[0038] As described above, the belt body 13 has a first belt 16, a second belt 17, and a connecting member 18. One end 16a of the first belt 16 is wound around and fixed to the drive pulley 35. The other end 16b of the first belt 16 is fixed to the connecting member 18. When the first belt 16 is wound around the drive pulley 35, the connecting member 18 is pulled up. When the connecting member 18 is forcibly pulled down, the first belt 16 is unwound (pulled out) from the drive pulley 35. There is a correlation between the amount of winding or unwinding (pulling out) of the first belt 16 in the drive pulley 35 and the amount of rotation of the output shaft of the motor 33. Therefore, the amount of winding or unwinding of the first belt 16 can be obtained based on the parameters related to the rotation of the motor 33.

[0039] As shown in Figure 3, the connecting member 18 includes an annular body 27 and a fastener (buckle) 28. The fastener 28 has a first member 28a and a second member 28b. The first member 28a and the second member 28b are separable and connectable. The first member 28a is attached to the other end 16b of the first belt 16. The second member 28b and the annular body 27 are connected by a short belt 29. The second belt 17 is inserted through the annular body 27.

[0040] The second belt 17 is folded back at the annular body 27 and draped over the annular body 27. The annular body 27 supports the folded second belt 17. As a result, the second belt 17 is supported by the annular body 27 without being fixed to it. Therefore, the second belt 17 is freely movable in both directions along its longitudinal direction (arrow X direction in Figure 3).

[0041] As shown in Figure 1, the second belt 17 is attached to the second fitting 12. The second belt 17 is made up of a single strip-shaped member. One end 17a of the second belt 17 is connected to the left second fitting 12. The other end 17d of the second belt 17 is connected to the right second fitting 12. The middle section 17c of the second belt 17 is looped over the connecting member 18.

[0042] The second belt 17 includes the intermediate section 17c, as well as the left leg belt section 19 and the right leg belt section 20. The left leg belt section 19 is the portion of the second belt 17 from the connecting member 18 (intermediate section 17c) to the left second attachment 12. The right leg belt section 20 is the portion of the second belt 17 from the connecting member 18 (intermediate section 17c) to the right second attachment 12. As described above, since the second belt 17 is not fixed to the annular body 27, the lengths of the left leg belt portion 19 and the right leg belt portion 20 can be freely changed. However, the sum of the lengths of the left leg belt portion 19 and the right leg belt portion 20 is constant. With this configuration, the user's walking, for example, is not restricted by the second belt 17, and the user can walk easily.

[0043] The assist device 10 of this embodiment further comprises a holder 42 and a protective member 50. The retainer 42 has the function of maintaining the distance between the first attachment 11 and the third attachment 40. As shown in Figures 1 and 2, the holder 42 includes a back frame 44. The back frame 44 connects the control box 30 of the first attachment 11 and the rear belt portion 40b of the third attachment 40 at approximately the center of the user's back BB. The back frame 44 is a plate-shaped member made of resin or metal. The back frame 44 is positioned between the belt body 13 and the user.

[0044] The upper end 44a of the back frame 44 is fixed to the control box 30. The lower end 44b of the back frame 44 is fixed to the upper rear belt portion 40b. This allows the back frame 44 to maintain the distance between the control box 30 and the rear belt portion 40b.

[0045] The protective member 50 is provided on the leg portion BL side (lower side) of the back frame 44. The protective member 50 is a plate-shaped member made of resin or metal. The protective member 50 is provided so as to extend downward from the lower end portion 44b of the back frame 44. Like the back frame 44, the protective member 50 is also positioned between the belt body 13 and the user. The retainer 42 and the protective member 50 will be described in detail later.

[0046] [Regarding processing by the control unit 15] As described above, the control unit 15 controls the actuator 14 based on the output of the rotation detector 36 and the output of the sensor 38. The control unit 15 can detect the user's movements or posture based on the output of the sensor 38. Therefore, the sensor 38 functions as a detector for detecting the user's movements or posture. For example, based on the output of the sensor 38, it can detect whether the user's upper body is leaning forward or upright, or whether the user is in a squatting position.

[0047] Furthermore, there is a correlation between the amount of winding and unwinding of the belt body 13 by the drive pulley 35 driven by the motor 33 and the user's posture. Therefore, the control unit 15 can also estimate the user's posture based on the rotation angle of the motor 33 detected by the rotation detector 36. Thus, the rotation detector 36 can be said to be a sensor for detecting the user's posture and movement.

[0048] The control unit 15 generates a control command based on at least one of the outputs of the rotation detector 36 and the sensor 38, and sends the control command to the actuator 14 (motor 33). The control unit 15 then controls the actuator 14. The actuator 14 operates based on control commands to wind up and unwind the belt body 13, as well as to temporarily pause its operation. As a result, the actuator 14 is controlled according to the user's posture.

[0049] When the assist device 10 is attached to the user, the motor 33 is controlled to operate in the direction of winding up the belt body 13 with a weaker force than when an assist force is constantly being generated (to generate torque). As a result, a weak tension is created in the belt body 13, and the belt body 13 does not loosen.

[0050] For example, when a user changes from an upright posture to a forward-leaning posture, tension is generated in the belt 13 due to this change in posture. In this case, the tension in the belt 13 caused by the change in posture forces the motor 33 to rotate (the motor 33 spins freely), and the belt 13 is moved forward without the power of the actuator 14. Alternatively, when a change in posture to a forward-leaning posture is initiated, the actuator 14 operates, that is, it rotates the motor 33 and moves the belt 13 forward.

[0051] Conversely, when the user changes from a forward-leaning posture to an upright posture, the belt 13 tends to loosen due to this change in posture. In this case, when the change in posture to an upright posture begins, the actuator 14 operates, that is, the motor 33 is rotated, to maintain the tension acting on the belt 13 and retract the belt 13.

[0052] In this way, the belt body 13 is retracted or untracted when the user's posture changes. When retraction or untraction occurs, the motor 33 rotates at a predetermined rotation angle, either actively or passively. This rotation angle is detected by the rotation detector 36. In this way, the amount of movement of the actuator 14 (motor 33) when the belt body 13 is retracted or untracted due to the user's posture change is detected by the rotation detector 36.

[0053] Based on the output of the rotation detector 36, the control unit 15 acquires the amount of movement of the actuator 14 (rotation angle of the motor 33) when the belt body 13 is wound up or unwound due to a change in the user's posture, and controls the actuator 14 to provide assistance to the user based on that amount of movement.

[0054] [Regarding the assisting force provided by the assisting device 10] The assist device 10 of this embodiment provides assistive force to the user in accordance with changes in the user's posture. When the actuator 14 (motor 33) winds the first belt 16 onto the drive pulley 35, the connecting member 18 pulls the second belt 17 towards the actuator 14, i.e., upward. The second belt 17 has both ends 17a and 17d attached to the left and right second attachments 12. The second attachments 12 are fixed to the lower leg BLL. Therefore, when the first belt 16 is wound onto the drive pulley 35, tension acts on both the first belt 16 and the second belt 17. This tension acts as an assisting force (supporting force) for the user. In other words, the actuator 14 generates an assisting force between the first mounting device 11 and the second mounting device 12.

[0055] When the user changes from an upright posture to a forward-leaning posture, the belt 13 is moved forward without the power of the actuator 14. This allows the user to comfortably assume a forward-leaning posture. If the user changes their posture from an upright position and maintains that posture at a predetermined forward-leaning angle, the belt body 13 will stop being fed out (wound). The start and end of the posture change can be detected by the rotation detector 36 or sensor 38.

[0056] Conversely, when the user begins to change their posture from a forward-leaning posture (bent-over posture) as shown in Figure 4 to an upright posture, the actuator 14 retracts the belt body 13 (first belt 16). This generates tension F in the belt body 13. This tension F generates a moment M in the direction that tries to make the upper body stand upright. The reaction force -F to the tension F is the force with which the actuator 14 tries to pull up the belt body 13. The moment M acts around the vicinity of the rotation axis C of the thigh. This moment M allows the user to easily return from a forward-leaning posture to an upright posture. Furthermore, the assist device 10 of this embodiment has a back frame 44 (holding body 42) that connects the control box 30 (first attachment 11) and the third attachment 40 and maintains a predetermined distance between them. Therefore, the tension F (reaction force -F) acting between the control box 30 and the third attachment 40 can be supported by the back frame 44, and a moment M can be efficiently generated while suppressing the load caused by the tension F from acting greatly on the user.

[0057] The assist device 10 of this embodiment generates the aforementioned moment M, thereby reducing the muscle load on the user's back muscles and quadriceps muscles in a forward-bending posture, and assisting the user's work movements. As a result, it is possible to reduce the strain on the lower back when bending forward and prevent lower back pain.

[0058] [Regarding the retainer 42 and protective member 50] Figure 5 is an enlarged view of the main part of the rear of the assist device 10. In Figure 5, the belt body 13 is shown by a dashed line. As described above, the back frame 44 of the holder 42 is positioned between the belt body 13 and the user. The belt body 13 extending from the control box 30 follows the outer surface 44c of the back frame 44. The outer surface 44c (first surface) is the surface of the back frame 44 that faces away from the user.

[0059] The outer surface 44c of the back frame 44 includes the first sliding contact surface 48. The first sliding contact surface 48 is the surface on the outer surface 44c that the belt body 13 slides against. The first sliding contact surface 48 extends from the upper end 44a to the lower end 44b of the back frame 44. The first sliding contact surface 48 has a smooth surface so as not to hinder the movement of the belt body 13.

[0060] The back frame 44 has a narrower width section 45a on the upper end 44a side and a wider width section 45b on the lower end 44b side. The width of the width detail 45a is almost constant from the upper end 44a. In other words, the width detail 45a is the portion of the back frame 44 whose width is constant at the upper end 44a. The width of the width detail 45a is slightly wider than the width of the first sliding contact surface 48. The wide section 45b is connected to the lower end of the narrow section 45a. The width of the wide section 45b gradually widens from the part connected to the narrow section 45a towards the lower end 44b.

[0061] The holder 42 includes a first guide 46 in addition to the back frame 44. The first guide 46 is provided on the outer surface 44c to prevent the belt body 13 from coming off the first sliding contact surface 48. The first guide 46 has a pair of wall portions 46a. The pair of wall portions 46a are block-shaped members formed of resin or the like. The pair of wall portions 46a are provided in the wide portion 45b. The pair of wall portions 46a are provided side by side on the left and right at a predetermined interval. The pair of wall portions 46a protrude from the outer surface 44c along both the left and right sides of the first sliding contact surface 48. The belt body 13 passes between the pair of wall portions 46a. Therefore, the first sliding contact surface 48 passes through the portion of the outer surface 44c between the pair of wall portions 46a. The distance between the pair of wall sections 46a is set to a size that allows the belt body 13 to pass through.

[0062] Figure 6 is a schematic diagram showing cross-sections of the holder 42 and the protective member 50. Figure 6 shows a cross-section of the holder 42 along the vertical direction at its horizontal center. In Figure 6, the belt body 13 (first belt 16, second belt 17, and connecting member 18) is shown by a dashed line. As shown in Figure 6, the rear belt portion 40b is fixed to the lower end portion 44b of the back frame 44. The rear belt portion 40b is fixed to the inner surface 44d of the back frame 44. Furthermore, the upper end portion 44a of the rear frame 44 is fixed to the rear plate 31 of the control box 30. The pair of wall portions 46a prevent the belt body 13 from coming off the first sliding contact surface 48 by opposing surfaces 46a1. The projection dimensions of the pair of wall portions 46a relative to the outer surface 44c are set to such an extent that they can guide the connecting member 18 of the belt body 13.

[0063] According to the above configuration, since the holder 42 has a back frame 44 that connects the first attachment 11 and the third attachment 40, it is possible to maintain the distance between the first attachment 11, which is attached to the back BB, and the third attachment 40, which is attached to the waist BW, without having to place frames or other structures on both the left and right sides of the user's body. As a result, it is possible to suppress the obstruction of the user's movements by the holder 42.

[0064] Furthermore, in this embodiment, since the back frame 44 has a first sliding contact surface 48 on the outer surface 44c facing away from the user, it is possible to suppress the belt body 13 from sliding against parts other than the first sliding contact surface 48, such as the user's back BB. This prevents the belt body 13 from sliding against the user's back BB and hindering the movement of the belt body 13.

[0065] Furthermore, since the holder 42 of this embodiment includes the first guide 46, even if the user twists their upper body from side to side and leans forward, causing the belt body 13 to shift position in the left-right direction, it is possible to prevent the belt body 13 from coming off the first sliding contact surface 48. As a result, it is possible to prevent the belt body 13 from coming off the back frame 44 and sliding against parts other than the back frame 44, thereby hindering the movement of the belt body 13, or causing the extension direction of the belt body 13 to deviate significantly from the winding direction of the actuator 14, thereby suppressing the loss of tension in the belt body 13, which is the source of the assist force.

[0066] As shown in Figures 5 and 6, the protective member 50 includes a protective plate 52 and a second guide 54. The protective plate 52 is positioned between the belt body 13 and the user. Therefore, the belt body 13 is provided along the outer surface 52c of the protective plate 52. The outer surface 52c (second surface) is the surface of the protective plate 52 that faces away from the user. A hinge 56 is provided between the protective plate 52 and the rear frame 44. The hinge 56 connects the protective plate 52 and the rear frame 44 so that they can swing in the front-to-back direction.

[0067] The outer surface 52c of the protective plate 52 includes a second sliding contact surface 58. The second sliding contact surface 58 is the surface on the outer surface 52c that the belt body 13 slides against. The second sliding contact surface 58 is made to be a smooth surface so as not to hinder the movement of the belt body 13.

[0068] The second guide 54 is provided on the outer surface 52c to prevent the belt body 13 from coming off the second sliding contact surface 58. The second guide 54 has a pair of wall portions 54a. The pair of wall portions 54a are block-shaped members formed of resin or the like. The pair of wall portions 54a are located approximately in the center in the vertical direction on the outer surface 52c. The pair of wall portions 54a are located side by side with a predetermined distance between them. The pair of wall portions 54a protrude from the outer surface 52c along both the left and right sides of the second sliding contact surface 58. The belt body 13 passes between the pair of wall portions 54a. Therefore, the second sliding contact surface 58 passes through the portion of the outer surface 52c between the pair of wall portions 54a. The distance between the pair of wall sections 54a is set to a size that allows the belt body 13 to pass through.

[0069] As shown in Figure 6, the pair of wall portions 54a prevent the belt body 13 from coming off the second sliding contact surface 58 by the opposing surfaces 54a1. The projection dimensions of the pair of wall portions 54a relative to the outer surface 52c are set to such an extent that they can guide the connecting member 18 of the belt body 13.

[0070] In this embodiment, a protective member 50 (or protective plate 52 of the protective member 50) is provided, which has a second sliding contact surface 58 on its outer surface 52c facing away from the user, to which the belt body 13 slides. This prevents the movement of the belt body 13 from being hindered by sliding contact with the user's buttocks or other areas below their waist.

[0071] Furthermore, when the user adopts a forward-leaning posture, tension is applied to the belt body 13 while it is aligned with the user's back and buttocks. Therefore, the belt body 13 presses against the user's back and buttocks. In this embodiment, the protective plate 52 is pivotably mounted on the lower end portion 44b of the back frame 44. Therefore, when the user changes their posture from an upright position to a forward-leaning position, the protective plate 52 pivots in accordance with the user's posture, allowing the back frame 44 and the protective plate 52 to conform to the user's back BB and buttocks. As a result, the belt body 13 can be properly slid against the first sliding contact surface 48 and the second sliding contact surface 58.

[0072] Furthermore, since the protective member 50 also includes a second guide 54, similar to the retainer 42, even if the belt body 13 attempts to shift position laterally due to the user twisting their upper body from side to side and leaning forward, it is possible to prevent the belt body 13 from coming off the second sliding contact surface 58.

[0073] [Regarding the second attachment device 12] Figure 7 is a view of the second device 12 attached to the user's right leg, seen from the rear, and Figure 8 is a view of the second device 12 attached to the user's right leg, seen from the front at an angle. The second attachment 12 has the same configuration on both the left and right sides. Therefore, the following explanation will focus on the right-side second attachment 12.

[0074] As described above, the second attachment 12 comprises a pair of lower leg belts 24, a foot strap 25, and a retaining strap 26. The upper ends 24a of the pair of lower leg belt sections 24 are connected to the second belt 17 (belt body 13). More specifically, a connector 60 is provided between the upper ends 24a of the pair of lower leg belt sections 24 and the other end 17d of the second belt 17 of the belt body 13. The connector 60 includes a buckle, etc. The connector 60 is positioned on the back side of the knee portion BN. The connector 60 has a first member 60a and a second member 60b. The first member 60a and the second member 60b are separable and connectable. The first member 60a is attached to the other end 17d of the second belt 17. The second member 60b has the upper ends 24a of the pair of lower leg belt portions 24 attached to it. Thus, the connector 60 connects the pair of lower leg belt portions 24 and the belt body 13 in a detachable manner.

[0075] The pair of lower leg belt sections 24 extend downward from the connector 60 on the dorsal side of the knee section BN, splitting to the left and right sides of the lower leg section BLL. As described above, the lower ends 24b of the pair of lower leg belt portions 24 are connected by a foot strap 25. Of the pair of lower leg belt portions 24, the right lower leg belt portion 24R, which runs along the right side of the lower leg portion BLL, is connected to one end 25a of the foot strap 25. Of the pair of lower leg belts 24, the left lower leg belt 24L, which runs along the left side of the lower leg BLL, is connected to the other end 25b of the foot strap 25.

[0076] Furthermore, each pair of lower leg belt sections 24 includes a front belt 24f and a rear belt 24r. The lower end of the front belt 24f of the right lower leg belt portion 24R is connected to the front end of one end 25a of the foot strap 25. The lower end of the rear belt 24r of the right lower leg belt portion 24R is connected to the rear end of one end 25a of the foot strap 25. The lower end of the front belt 24f of the left lower leg belt section 24L is connected to the front end of the other end 25b of the foot strap 25. The lower end of the rear belt 24r of the left lower leg belt section 24L is connected to the rear end of the other end 25b of the foot strap 25.

[0077] The foot strap 25 is a strip-shaped member that passes over the user's sole SO in the lateral direction. The foot strap 25 has a contact surface 25c that comes into contact with the user's sole SO. Therefore, the user's leg is placed on the foot strap 25.

[0078] The front belt 24f of the right lower leg belt section 24R and the front belt 24f of the left lower leg belt section 24L are connected by a connecting band 24c. The connecting band 24c is positioned to follow the upper surface of the user's foot BF by connecting the lower ends of both belts 24f. This prevents the foot strap 25 from coming off the user's foot BF.

[0079] As described above, the retaining strap 26 is attached to the knee joint BN. In this embodiment, the retaining strap 26 is attached to the lower part of the knee joint BN. The retaining strap 26 is provided with fastening members such as hook-and-loop fasteners at both ends. When the retaining strap 26 is wrapped around the knee portion BN, both ends of the retaining strap 26 are fastened together by the fastening members. In this way, the retaining strap 26 is attached to the knee portion BN.

[0080] The retaining band 26 is provided with a pair of holes 26a. The pair of holes 26a penetrate the retaining band 26 in the vertical direction. The pair of lower leg belt portions 24 pass through the pair of holes 26a. As a result, the retaining strap 26 is provided on the pair of lower leg belt portions 24. A pair of lower leg belt portions 24 are movably passed through a pair of holes 26a. This pair of holes 26a allows the retaining band 26 and the pair of lower leg belt portions 24 to move relative to each other along the extension direction of the pair of lower leg belt portions 24.

[0081] Here, the combined length of the portion of the belt body 13 extending from the actuator 14 and the second attachment 12 can be adjusted by the actuator 14. Furthermore, since the retaining strap 26 and the pair of lower leg belts 24 are movable relative to each other along the extension direction of the pair of lower leg belts 24, the distance between the foot strap 25 and the retaining strap 26 can be adjusted according to the height of the user's knee BN. As a result, by aligning the position of the retaining strap 26 with the position of the user's knee BN, the second attachment device 12 can be properly fitted to users of various heights without having to adjust the length of the pair of lower leg belts 24.

[0082] In the assist device 10 of this embodiment, it is conceivable that the second attachment 12 be fixed to the knee portion BN by a belt or the like. However, if the second attachment 12 is configured to be fixed only at the knee, there is a risk that the second attachment 12 may shift position due to the tension of the belt body 13 or large changes in the user's posture. If the second attachment 12 shifts position, it will reduce the tension of the belt body 13, which provides the assisting force, making it impossible to generate the assisting force efficiently.

[0083] In this regard, in this embodiment, the second attachment device 12 preferably comprises a pair of lower leg belt portions 24 whose upper ends 24a are connected to the belt body 13, a foot strap 25 that connects the lower ends 24b of the pair of lower leg belt portions 24 and has a contact surface 25c that comes into contact with the sole SO of the user's foot, and a retaining strap 26 provided on the pair of lower leg belt portions 24 and attached to the knee portion BN of the user. In this case, the foot strap 25 of the second device 12 is attached to the sole SO of the user's foot. Therefore, the tension from the belt body 13 acts to pull up the sole SO of the user's foot, preventing the second device 12 from shifting position. As a result, assist power can be generated efficiently.

[0084] [Regarding other embodiments] Figure 9 shows a holder 42 according to another embodiment. As shown in Figure 9, this embodiment differs from the above embodiment in that the width of the back frame 44 is constant, and the holder 42 comprises a pair of waist frames 64.

[0085] In this embodiment, the width of the back frame 44 is substantially constant from the upper end 44a to the lower end 44b. Therefore, the back frame 44 is a rectangular shape that is elongated in the vertical direction. The first guide 46 in this embodiment is provided along the left and right edges of the back frame 44.

[0086] Figure 10 is a cross-sectional view taken along the line AA in Figure 9. As shown in Figure 10, the first guide 46 has a pair of wall portions 70. The pair of wall portions 70 are integrally formed with the back frame 44. The pair of wall portions 70 extend vertically along the left and right edges of the back frame 44. Therefore, the pair of wall portions 70 extend along both the left and right sides of the first sliding contact surface 48. The pair of wall portions 70 protrude from the first sliding contact surface 48. Each of the pair of wall portions 70 has a wall body 70a that protrudes from the first sliding surface 48 and a projection 70b that protrudes inward from the tip of the wall body 70a.

[0087] The pair of wall portions 70 prevent the belt body 13 from coming off the first sliding contact surface 48 by the wall body 70a and the protruding portion 70b. In other words, the belt body 13 moves within the space enclosed by the back frame 44 and the pair of wall sections 70. This makes it possible to more effectively prevent the belt body 13 from coming off the first sliding contact surface 48.

[0088] Returning to Figure 9, the pair of waist frames 64 extend from the lower end 44b of the back frame 44 in the left-right direction. The pair of waist frames 64 are formed of an elastically deformable material such as resin. For example, if the back frame 44 is made of resin, the pair of waist frames 64 are integrally attached to the back frame 44. If the back frame 44 is made of metal, the pair of waist frames 64 are fixed to the back frame 44 by connecting members such as screws or rivets. In this embodiment, a pair of lumbar frames 64 are integrally provided with respect to the back frame 44.

[0089] The pair of waist frames 64 extend along the upper rear belt portion 40b. The pair of waist frames 64 are fixed to the upper rear belt portion 40b. The ends 64a of the pair of waist frames 64 extend to the connecting portion 40c. A pair of waist frames 64, fixed to the upper rear belt portion 40b, curve together with the upper rear belt portion 40b and are wrapped around the user's waist BW, thus being attached to the waist BW. As a result, the back frame 44 is connected to a pair of waist frames 64 that are wrapped around the waist BW, so that a moment M (Figure 4) can be generated more efficiently compared to the case where the back frame 44 is fixed only to the rear belt portion 40b of the third attachment 40, which is a strip-shaped member made of fabric or the like, as in the above embodiment.

[0090] Furthermore, the protective plate 52 of the protective member 50 in this embodiment is rectangular in shape and elongated in the vertical direction. The second guide 54 is provided along the left and right edges of the protective plate 52. Figure 11 is a cross-sectional view taken along the line BB in Figure 9. As shown in Figure 11, the second guide 54 has a pair of wall portions 72. The pair of wall portions 72 are integrally formed with the protective plate 52. The pair of wall portions 72 extend vertically along the left and right edges of the protective plate 52. Therefore, the pair of wall portions 72 extend along both the left and right sides of the second sliding contact surface 58. The pair of wall portions 72 protrude from the second sliding surface 58. Each of the pair of wall portions 72 has a wall body 72a that protrudes toward the second sliding surface 58, and a projection 72b that protrudes inward from the tip of the wall body 72a.

[0091] The pair of wall portions 72 prevent the belt body 13 from coming off the second sliding contact surface 58 by the wall body 72a and the protruding portion 72b. In other words, the belt body 13 moves within the space enclosed by the protective plate 52 and the pair of wall portions 72. This makes it possible to more effectively prevent the belt body 13 from coming off the second sliding contact surface 58.

[0092] 〔others〕 The embodiments disclosed herein are illustrative in all respects and not restrictive. In the embodiments described above, the back frame 44 and the protective member 50 are shown connected by a hinge 56, but the back frame 44 and the protective member 50 may be formed as a single unit. Furthermore, although the above embodiments show the case in which a protective member 50 is provided, the protective member 50 is not required. In this case, the assist device 10 can be made lighter. However, by providing the protective member 50, as described above, it is possible to suppress the obstruction of the movement of the belt body 13 by preventing it from sliding against the buttocks or other areas below the waist.

[0093] Furthermore, although the above embodiments illustrate the case in which the retaining strap 26 of the second attachment 12 is attached to the lower part of the knee BN, the retaining strap 26 may also be attached to the upper part of the knee BN, or it may be in the form of a supporter that is attached from the upper to the lower part of the knee BN.

[0094] The scope of the present invention is not limited to the embodiments described above, and includes all modifications within the scope of equivalence to the configurations described in the claims. [Explanation of Symbols]

[0095] 10 Assist device 11 First attachment 12 Second attachment 13 Belt body 14 Actuator 15 Control unit 16 First belt 16a One end 16b Other end 17 Second belt 17a One end 17c Middle section 17d Other end 18 Connecting member 19 Left leg belt 20 Right leg belt section 21 Base 22 Shoulder belt 22a Tip portion 23 Cushioning member 24 Lower leg belt portion 24L Left lower leg belt section 24R Right lower leg belt section 24a Upper end 24b Lower end 24c Connecting band 24f Front belt 24r Rear belt 25 Foot strap 25a One end 25b Other end 25c Contact surface 26 Retaining band 26a Hole 27 Annular body 28 Fastener 28a First component 28b Second component 29 Short belt 30 Control box 31 Rear plate 32 Cover 32a Opening 33 Motor 34 Reducer section 34a Output shaft 35 Drive pulley 36 Rotation detector 37 Battery 38 Sensor 40 Third attachment 40a Front belt section 40b Rear belt section 40c Connecting part 40d Connector 42 Holder 44 Rear frame 44a Upper end 44b Lower end 44c Outside surface 44d Inside surface 45a Width detail 45b Wide section 46 First guide 46a Wall section 46a1 Opposing surface 48 First sliding contact surface 50 Protective member 52 Protective plate 52c Outer surface 54 Second guide 54a Wall section 54a1 Opposing surface 56 Hinge 58 Second sliding contact surface 60 Connector 60a First member 60b Second member 64 Waist frame 64a End 70 Wall part 70a Wall body 70b Projection part 72 Wall portion 72a Wall body 72b Projection portion

Claims

1. A first attachment device that is worn on at least the shoulder of the user, A second attachment device is fitted to each of the user's left and right legs, A third attachment device to be worn on the user's waist, A belt body is provided along the user's back, spanning the first and second attachments, An actuator provided on the first mounting device that enables winding and unwinding of a portion of the belt body, The system includes a back frame that connects the first attachment and the third attachment at the center of the user's back and maintains the distance between them, In the aforementioned back frame, the first surface facing away from the user includes a first sliding contact surface with which the belt body slides, The belt body is further provided with a first guide that prevents it from coming off the first sliding contact surface, The first guide is a wall portion that protrudes from the first surface along both the left and right sides of the first sliding surface. Assist device.

2. The rear frame further comprises a plate-shaped protective member provided on the leg side, The protective member has a second surface facing away from the user, which includes a second sliding contact surface with which the belt body slides. The assist device according to claim 1.

3. The protective member includes a second guide that prevents the belt body from coming off the second sliding contact surface. The assist device according to claim 2.

4. The aforementioned second attachment device is, A pair of lower leg belt portions whose upper ends are connected to the belt body, A foot strap that connects the lower ends of the pair of lower leg belts and has a contact surface that comes into contact with the soles of the user's feet, The system includes a retaining strap provided on the pair of lower leg belts and attached to the user's knee. The assist device according to any one of claims 1 to 3.

5. The retaining band and the pair of lower leg belt portions are provided so as to be able to move relative to each other along the extension direction of the pair of lower leg belt portions. The assist device according to claim 4.

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