Upper arm motion assist device

Abstract

To provide an upper arm motion assist device that suppresses a decrease in the degree of freedom of the motion of an upper arm and assists the motion of the upper arm.SOLUTION: An upper arm motion assist device 1 is worn by a user H to assist the motion of an upper arm HA of the user H. The upper arm motion assist device 1 comprises: a torso attachment section 2 that is detachably attached to a torso HB of the user H; an upper arm attachment section 3 that is detachably attached to the upper arm HA; and a remote motion center mechanism 4 that is provided between the torso attachment section 2 and the upper arm attachment section 3. The remote motion center mechanism 4 includes a remote motion center 5 that is arranged at a position of the shoulder joint of the user H, rotates in accordance with the motion of the upper arm HA around the remote motion center 5, and presses the upper arm HA via the upper arm attachment section 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an upper arm movement assisting device.

Background Art

[0002] For example, when performing an operation of lifting a heavy object or performing an operation while keeping the arm raised, a device that presses the operator's arm from behind to assist the movement of the arm is known. For example, Patent Document 1 discloses a work support device that supports the operator's arm when the operator raises the arm to perform a task.

[0003] The work support device of Patent Document 1 includes an elastic support arm having elasticity, an arm receiving portion provided at the tip of the elastic support arm for supporting a part of the operator's arm from below, an arm holding portion for rotating the elastic support arm in the vertical direction, and an arm moving means for rotating the arm holding portion in the horizontal direction. The arm holding portion and the arm moving means are located below the base of the operator's arm.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the work support device of Patent Document 1, since the rotation center of the elastic support arm is different from the position of the shoulder joint, the elastic support arm does not follow the movement of the upper arm, and the range in which the assisting force for assisting the movement of the upper arm can be obtained is limited. As a result, the degree of freedom of movement of the upper arm may decrease.

[0006] An object of the present invention is to provide an upper arm movement assisting device that suppresses a decrease in the degree of freedom of movement of the upper arm and assists the movement of the upper arm.

Means for Solving the Problems

[0007] The upper arm motion assistance device according to the present invention is an upper arm motion assistance device that is worn by a user and assists the motion of the user's upper arm, and includes a body mounting portion that is detachably mounted on the body of the user, an upper arm mounting portion that is detachably mounted on the upper arm, and a remote motion center mechanism provided between the body mounting portion and the upper arm mounting portion. The remote motion center mechanism has a remote motion center disposed at the position of the user's shoulder joint, rotates following the motion of the upper arm around the remote motion center, and presses the upper arm via the upper arm mounting portion.

Effect of the Invention

[0008] According to the present invention, it is possible to suppress a decrease in the degree of freedom of movement of the upper arm and assist the motion of the upper arm.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description and drawings, common components are denoted by common reference numerals. The description of the components denoted by common reference numerals will be omitted as appropriate.

[0011] (Configuration of the upper arm motion assist device) FIG. 1 is a rear perspective view showing a state in which the upper arm motion assist device 1 is worn on the user H. FIG. 2 is a rear perspective view of the upper arm motion assist device 1. FIG. 3 is a front perspective view of the upper arm motion assist device 1. FIG. 4 is a side view of the upper arm motion assist device 1.

[0012] In FIG. 1, the upper arm motion assist device 1 is worn on the user H and used to assist the motion of the upper arm HA of the user H. In the following description, "front" indicates the front side of the user H, "rear" indicates the rear side of the user H, "left" indicates the left side of the user H, "right" indicates the right side of the user H, "up" indicates the upper side of the user H, and "down" indicates the lower side of the user H.

[0013] The upper arm motion assist device 1 includes a body mounting part 2 that is detachably attached to the body HB of the user H, an upper arm mounting part 3 that is detachably attached to the upper arm HA of the user H, and a remote center of motion (RCM) mechanism 4 (hereinafter referred to as the RCM mechanism) provided between the body mounting part 2 and the upper arm mounting part 3. The RCM mechanism is a mechanism that arranges the center of rotation, that is, the remote center of motion, at a position away from the center of rotation of the motor, and realizes a pivoting motion with the remote center of motion as a fixed point. The RCM mechanism 4 has a remote center of motion 5 disposed at the position of the shoulder joint of the user H, rotates around the remote center of motion 5 following the motion of the upper arm HA of the user H, and is configured to press the upper arm HA via the upper arm mounting part 3. The upper arm motion assist device 1 is configured not to cover the side and front of the shoulder of the user H because the remote center of motion 5 of the RCM mechanism 4 is disposed at the position of the shoulder joint of the user H. In this embodiment, the upper arm motion assist device 1 includes a pair of upper arm mounting parts 3 and a pair of RCM mechanisms 4, and is configured to assist the motion of the left and right upper arms HA of the user H.

[0014] (Body mounting part) The body mounting part 2 includes a waist belt 11 that is wound around and attached to the waist of the user H, a pair of shoulder belts 12 that are wound around and attached to the respective left and right shoulders of the user H, a frame 13 disposed on the back of the user H and connecting the waist belt 11 and the pair of shoulder belts 12, a first cylindrical body 14 fixed to the frame 13 and protruding in the left-right direction from the frame 13, and a second cylindrical body 15 fixed to the frame 13 below the first cylindrical body 14 and protruding in the left-right direction from the frame 13. In FIGS. 2 to 4, the illustration of the waist belt 11 and the pair of shoulder belts 12 is omitted.

[0015] The waist belt 11 is composed of a long cloth member, a rubber member, etc., is wound around the waist of the user H, and is detachably attached to the waist. The waist belt 11 has a detachable fixing part such as a hook-and-loop fastener, and is fixed by the detachable fixing part in a state of being wound around the waist of the user H. Note that the hook-and-loop fastener is detachably fixed by strongly pressing a loop surface provided with a plurality of fine loops and a hook surface provided with a plurality of fine key-shaped parts, so that the key-shaped parts of the hook surface are locked to the loop surface.

[0016] The pair of shoulder belts 12 are composed of a long cloth member, a rubber member, etc., are wound around the shoulders of the user H, and are detachably attached to the shoulders. The pair of shoulder belts 12 are provided with a buckle (not shown) and are configured to be adjustable in length, and the degree of adhesion to the user H is adjustable.

[0017] The frame 13 is formed in a rectangular shape. The frame 13 is composed of a hard material such as resin or metal. The frame 13 includes a lower frame 21 fixed to the waist belt 11, upper frames 22 fixed to each of the pair of shoulder belts 12, a left frame 23 connecting the left end of the lower frame 21 and the left end of the upper frame 22, and a right frame 24 connecting the right end of the lower frame 21 and the right end of the upper frame 22.

[0018] The lower frame 21 and the upper frame 22 are composed of plate members and extend in the left-right direction. The lower frame 21 and the upper frame 22 are arranged parallel to each other. The lower frame 21 and the upper frame 22 are not limited to being composed of plate members, and may be, for example, cylindrical members.

[0019] The left frame 23 and the right frame 24 are composed of cylindrical members and extend in the up-down direction. The left frame 23 and the right frame 24 are arranged parallel to each other. That is, the central axis of the left frame 23 and the central axis of the right frame 24 are parallel to each other. The left frame 23 and the right frame 24 are not limited to being composed of cylindrical members, and may be, for example, plate members.

[0020] The first cylinder body 14 is disposed to intersect the left frame 23 and the right frame 24. The first cylinder body 14 is fixed to the left frame 23 at the first left fixing portion 31 and fixed to the right frame 24 at the first right fixing portion 32 (see FIGS. 2 and 3). The first cylinder body 14, the first left fixing portion 31, and the first right fixing portion 32 are made of a hard material such as resin or metal.

[0021] The second cylinder body 15 is disposed to intersect the left frame 23 and the right frame 24. The second cylinder body 15 is fixed to the left frame 23 at the second left fixing portion 33 and fixed to the right frame 24 at the second right fixing portion 34. The second cylinder body 15, the second left fixing portion 33, and the second right fixing portion 34 are made of a hard material such as resin or metal.

[0022] The left end portions of the first cylinder body 14 and the second cylinder body 15 protrude to the left side of the left frame 23. The right end portions of the first cylinder body 14 and the second cylinder body 15 protrude to the right side of the right frame 24.

[0023] Since the first left fixing portion 31, the first right fixing portion 32, the second left fixing portion 33, and the second right fixing portion 34 have the same configuration, the first left fixing portion 31 will be described, and the descriptions of the first right fixing portion 32, the second left fixing portion 33, and the second right fixing portion 34 will be omitted.

[0024] The first left fixing portion 31 has a block body 41 extending in the first direction (front-rear direction), a first notch portion 42 provided at one end of the block body 41 in the first direction and notched in the second direction (up-down direction) orthogonal to the first direction, a first fastening portion 43 for fastening the open end of the first notch portion 42, a second notch portion 44 provided at the other end of the block body 41 in the first direction and notched in the third direction (left-right direction) orthogonal to the first direction and the second direction, and a second fastening portion 45 for fastening the open end of the second notch portion 44. The first notch portion 42 and the second notch portion 44 have a C-shaped cross section. For the first fastening portion 43 and the second fastening portion 45, for example, bolts and nuts are used.

[0025] The first left fixing part 31 fixes the first cylinder body 14 to the left frame 23 by inserting the left frame 23 into the first notch part 42, inserting the first cylinder body 14 into the second notch part 44, clamping the open end of the first notch part 42 by the first fastening part 43, and clamping the open end of the second notch part 44 by the second fastening part 45.

[0026] The first right fixing part 32 fixes the first cylinder body 14 to the right frame 24 by inserting the right frame 24 into the first notch part 42, inserting the first cylinder body 14 into the second notch part 44, clamping the open end of the first notch part 42 by the first fastening part 43, and clamping the open end of the second notch part 44 by the second fastening part 45.

[0027] By loosening the first fastening part 43 of the first left fixing part 31 and the first right fixing part 32, the vertical position of the first cylinder body 14 relative to the frame 13 can be adjusted. By loosening the second fastening part 45 of the first left fixing part 31 and the first right fixing part 32, the horizontal position of the first cylinder body 14 relative to the frame 13 can be adjusted.

[0028] The second left fixing part 33 fixes the second cylinder body 15 to the left frame 23 by inserting the left frame 23 into the first notch part 42, inserting the second cylinder body 15 into the second notch part 44, clamping the open end of the first notch part 42 by the first fastening part 43, and clamping the open end of the second notch part 44 by the second fastening part 45.

[0029] The second right fixing part 34 fixes the second cylinder body 15 to the right frame 24 by inserting the right frame 24 into the first notch part 42, inserting the second cylinder body 15 into the second notch part 44, clamping the open end of the first notch part 42 by the first fastening part 43, and clamping the open end of the second notch part 44 by the second fastening part 45.

[0030] By loosening the first fastening parts 43 of the second left fixing part 33 and the second right fixing part 34, the vertical position of the second cylinder body 15 with respect to the frame 13 can be adjusted. By loosening the second fastening parts 45 of the second left fixing part 33 and the second right fixing part 34, the horizontal position of the second cylinder body 15 with respect to the frame 13 can be adjusted.

[0031] By loosening the first fastening part 43 and the second fastening part 45, the vertical and horizontal positions of the first cylinder body 14 and the second cylinder body 15 can be adjusted, and the position of the RCM mechanism 4 described later can be adjusted to an appropriate position according to the user H.

[0032] The body mounting part 2 is mounted on the body HB of the user H by tightening the waist belt 11 and fixing it by the detachable fixing part in a state where a pair of shoulder belts 12 are mounted on both shoulders of the user H and the waist belt 11 is mounted on the waist of the user H.

[0033] (Upper arm mounting part) The pair of upper arm mounting parts 3 have the same configuration as each other. One upper arm mounting part 3 will be described, and the description of the other upper arm mounting part 3 will be omitted.

[0034] The upper arm mounting part 3 is arranged behind the upper arm HA of the user H. The upper arm mounting part 3 includes a semi-cylindrical main body 51 on which the upper arm HA is arranged, a pair of through holes 52 penetrating both circumferential ends of the main body 51, and a band 53 (see FIG. 1) passed through the pair of through holes 52.

[0035] The main body 51 has a first central axis 50. The cross-sectional shape of the main body 51 is formed in a semi-circular arc shape. The upper arm HA of the user H is arranged on the semi-circular arc-shaped inner peripheral surface of the main body 51. The main body 51 is made of a hard material such as resin or metal. The main body 51 is not limited to the semi-cylindrical shape, and for example, it may be semi-elliptical.

[0036] The band 53 is composed of a long cloth member, a rubber member, etc. The band 53 has a detachable fixing part such as a hook-and-loop fastener, for example.

[0037] The upper arm mounting portion 3 is mounted on the upper arm HA by tightening the band 53 in a state where the rear portion of the upper arm HA inserted between the main body 51 and the band 53 is in contact with the inner peripheral surface of the main body 51 and fixing it with the detachable fixing portion.

[0038] (RCM mechanism) The pair of RCM mechanisms 4 have the same configuration as each other. One of the RCM mechanisms 4 will be described, and the description of the other RCM mechanism 4 will be omitted.

[0039] The RCM mechanism 4 includes a shaft portion 61 fixed to the body mounting portion 2, a rotating portion 62 rotatably provided about the second central axis 60 with respect to the shaft portion 61, an extendable and retractable parallel link portion 63 provided on the rotating portion 62, and an elastic portion 64 that extends or contracts the parallel link portion 63.

[0040] The shaft portion 61 has the second central axis 60. The second central axis 60 of the shaft portion 61 intersects the first central axis 50 of the main body 51. The point where the first central axis 50 of the main body 51 and the second central axis 60 of the shaft portion 61 intersect constitutes the remote motion center 5. The remote motion center 5 is arranged at a position away from the shaft portion 61 and the main body 51, and is adjusted to the position of the shoulder joint of the user H wearing the upper arm motion assist device 1.

[0041] When the upper arm motion assist device 1 is worn on the user H, the shaft portion 61 is arranged obliquely downward to the rear with respect to the shoulder of the user H. One end of the shaft portion 61 is directed upward and the other end is directed downward. The shaft portion 61 is composed of a cylindrical member. The shaft portion 61 is composed of a hard material such as resin or metal.

[0042] When the right frame 24 (or the left frame 23) is arranged along the vertical direction, the second central axis 60 of the shaft portion 61 is inclined with respect to the vertical line V (hereinafter referred to as the vertical line) (see FIG. 4). The angle θ1 of the second central axis 60 of the shaft portion 61 with respect to the vertical line V is, for example, 30°.

[0043] The shaft portion 61 is fixed to the first cylindrical body 14 by the first clamp 66 and fixed to the second cylindrical body 15 by the second clamp 67.

[0044] The first clamp 66 has the same configuration as the first left fixing portion 31. That is, the first clamp 66 has a block body 41, a first notch portion 42, a first fastening portion 43, a second notch portion 44, and a second fastening portion 45. The shaft portion 61 is inserted into the first notch portion 42 of the first clamp 66, the first cylindrical body 14 is inserted into the second notch portion 44, the open end of the first notch portion 42 is tightened by the first fastening portion 43, and the open end of the second notch portion 44 is tightened by the second fastening portion 45, thereby fixing the shaft portion 61 to the first cylindrical body 14.

[0045] The second clamp 67 is disposed below the first clamp 66. The second clamp 67 has a first clamping member 68 that clamps the shaft portion 61 and a second clamping member 69 that clamps the second cylindrical body 15. The first clamping member 68 and the second clamping member 69 have a U-shaped cross section. In FIG. 4, the open end of the first clamping member 68 faces the depth direction of the paper surface, and the open end of the second clamping member 69 faces the lower left direction of the paper surface. The open end of the first clamping member 68 and the open end of the second clamping member 69 are tightened by a fastening portion 70.

[0046] The rotating portion 62 has a first rotating portion 62a disposed between one end of the shaft portion 61 and the first clamp 66, and a second rotating portion 62b disposed between the first clamp 66 and the second clamp 67.

[0047] The first rotating portion 62a is composed of a square cylindrical member. The openings at both ends of the first rotating portion 62a are directed in the front-rear direction. Insertion holes into which the shaft portion 61 is inserted are provided on the upper surface and the lower surface of the first rotating portion 62a. First connecting shafts 81, which will be described later, are provided on the left side surface and the right side surface of the first rotating portion 62a.

[0048] The second rotating part 62b is composed of a square tube member. The openings at both ends of the second rotating part 62b are directed in the front-rear direction. Insertion holes for inserting the shaft part 61 are provided on the upper surface and the lower surface of the second rotating part 62b. The second connecting shaft 82 and the eighth connecting shaft 88, which will be described later, are provided on the left side surface and the right side surface of the second rotating part 62b.

[0049] A pair of parallel link parts 63 are provided symmetrically with respect to a virtual plane including the first central axis 50 of the main body 51 and the second central axis 60 of the shaft part 61. The pair of parallel link parts 63 have the same configuration as each other. One of the parallel link parts 63 will be described, and the description of the other parallel link part 63 will be omitted.

[0050] The parallel link part 63 has a first link 71, a second link 72 arranged in parallel with the first link 71, a third link 73 arranged to intersect the first link 71, and a fourth link 74 arranged in parallel with the third link 73. The first link 71 and the second link 72 are composed of plate members having a linear shape. The length of the first link 71 is longer than the length of the second link 72. The third link 73 and the fourth link 74 are composed of crank-shaped plate members in which three straight portions are alternately connected at right angles (see FIGS. 2 and 3). The length of the straight portion on one end side of the third link 73 is the same as the length of the straight portion on one end side of the fourth link 74. The length of the straight portion on the other end side of the third link 73 is longer than the length of the straight portion on the other end side of the fourth link 74.

[0051] The parallel link portion 63 includes a first connecting shaft 81 that rotatably connects one end of the first link 71 and the first rotating portion 62a, a second connecting shaft 82 that rotatably connects one end of the second link 72 and the second rotating portion 62b, a third connecting shaft 83 that rotatably connects one end of the third link 73 and the main body 51 of the upper arm mounting portion 3, a fourth connecting shaft 84 that rotatably connects one end of the fourth link 74 and the main body 51 of the upper arm mounting portion 3, a fifth connecting shaft 85 that rotatably connects the other end of the second link 72 and the other end of the third link 73, a sixth connecting shaft 86 that rotatably connects the other end of the first link 71 and the other end of the fourth link 74, a seventh connecting shaft 87 that rotatably connects an intermediate portion between one end and the other end of the first link 71 and an intermediate portion between one end and the other end of the third link 73, and an eighth connecting shaft 88 that rotatably connects one end of an elastic portion 64, which will be described later, and the second rotating portion 62b. Central axes of the first to eighth connecting shafts 81 to 88 are parallel to each other. Central axes of the first to eighth connecting shafts 81 to 88 are orthogonal to a first central axis 50 of the main body 51 and a second central axis 60 of the shaft portion 61. The third connecting shaft 83 is disposed rearward of the fourth connecting shaft 84. In FIG. 4, the third connecting shaft 83 is disposed behind a through hole 52 provided in the main body 51 of the upper arm mounting portion 3, and the fourth connecting shaft 84 is disposed in front of the through hole 52. The eighth connecting shaft 88 is disposed obliquely downward in front of the second connecting shaft 82. The fifth connecting shaft 85, the sixth connecting shaft 86, and the eighth connecting shaft 88 each extend in the left-right direction and are shared by one parallel link portion 63 and the other parallel link portion 63.

[0052] When the parallel link portion 63 is viewed from the side, a line segment connecting the central positions in the order of the first connecting shaft 81, the second connecting shaft 82, the fifth connecting shaft 85, the seventh connecting shaft 87, and the first connecting shaft 81 forms a parallelogram. A line segment connecting the central positions in the order of the third connecting shaft 83, the fourth connecting shaft 84, the sixth connecting shaft 86, the seventh connecting shaft 87, and the third connecting shaft 83 forms a parallelogram.

[0053] The parallel link portion 63 rotates about the second central axis 60 of the shaft portion 61 via the first rotating portion 62a and the second rotating portion 62b. The first link 71 rotates about the central axis of the first connecting shaft 81. The second link 72 rotates about the central axis of the second connecting shaft 82. The third link 73 rotates about the central axis of the third connecting shaft 83. The fourth link 74 rotates about the central axis of the fourth connecting shaft 84.

[0054] When the parallel link portion 63 is viewed from the side, the first link 71 rotates counterclockwise about the central axis of the first connecting shaft 81, the second link 72 rotates counterclockwise about the central axis of the second connecting shaft 82, the third link 73 rotates clockwise about the central axis of the third connecting shaft 83, and the fourth link 74 rotates clockwise about the central axis of the fourth connecting shaft 84, whereby the parallel link portion 63 extends.

[0055] Here, with respect to the parallel link portion 63, "extension" means that when the parallel link portion 63 is viewed from the side, among the two diagonals of the parallelogram formed by the line segments connecting the respective central positions in the order of the first connecting shaft 81, the second connecting shaft 82, the fifth connecting shaft 85, the seventh connecting shaft 87, and the first connecting shaft 81, the diagonal (one diagonal) connecting the central positions of the second connecting shaft 82 and the seventh connecting shaft 87 extends. With respect to the parallel link portion 63, "contraction" means that when the parallel link portion 63 is viewed from the side, among the two diagonals of the parallelogram formed by the line segments connecting the respective central positions in the order of the first connecting shaft 81, the second connecting shaft 82, the fifth connecting shaft 85, the seventh connecting shaft 87, and the first connecting shaft 81, the diagonal (the other diagonal) connecting the central positions of the first connecting shaft 81 and the fifth connecting shaft 85 contracts. In the present invention, "extending or contracting the parallel link portion" means extending one of the two diagonals of the parallelogram when the parallel link portion 63 is viewed from the side, or contracting the other diagonal. The parallel link portion 63 unfolds forward and presses the upper arm mounting portion 3 by extending or contracting.

[0056] When looking at the parallel link portion 63 from the side, the first link 71 rotates clockwise about the central axis of the first connecting shaft 81, the second link 72 rotates clockwise about the central axis of the second connecting shaft 82, the third link 73 rotates counterclockwise about the central axis of the third connecting shaft 83, and the fourth link 74 rotates counterclockwise about the central axis of the fourth connecting shaft 84, whereby the parallel link portion 63 is folded.

[0057] The elastic portion 64 is disposed between the pair of parallel link portions 63. The elastic portion 64 has one end and the other end, and is configured such that the other end extends in a direction away from the one end. One end of the elastic portion 64 is rotatably connected to the eighth connecting shaft 88, and the other end is rotatably connected to the sixth connecting shaft 86. The elastic portion 64 presses the sixth connecting shaft 86 in a direction away from the one end. By the elastic portion 64 pressing the sixth connecting shaft 86, the parallel link portion 63 is extended. The direction in which the other end of the elastic portion 64 moves away from the one end is the direction in which the parallel link portion 63 is extended. The force by which the elastic portion 64 extends the parallel link portion 63 is a force that cancels the weight of the upper arm HA and assists the operation of raising the upper arm HA, and is also referred to as an assisting force.

[0058] By pressing the sixth connecting shaft 86, the elastic portion 64 generates a torque around a virtual line 90 (see FIG. 4) that passes through the remote motion center 5 and is orthogonal to the first central axis 50 and the second central axis 60. In FIG. 4, the virtual line 90 extends in the depth direction of the paper surface, and a torque is generated counterclockwise around the virtual line 90. Due to the torque generated by the elastic portion 64, the parallel link portion 63 is extended, and the upper arm mounting portion 3 is pressed by the parallel link portion 63 that unfolds forward, assisting the operation of raising the upper arm HA. The torque that assists the operation of raising the upper arm HA is also referred to as an assisting torque.

[0059] In this embodiment, the elastic part 64 is constituted by a gas spring. The elastic part 64 as a gas spring has a cylinder 96 with gas enclosed therein and a rod 97 accommodated in the cylinder 96 and provided so as to be able to advance and retreat with respect to the cylinder 96. The elastic part 64 as a gas spring has an end part of the cylinder 96 rotatably connected to the eighth connecting shaft 88 and an end part of the rod 97 rotatably connected to the sixth connecting shaft 86. The elastic part 64 as a gas spring presses the sixth connecting shaft 86 when the rod 97 advances from the cylinder 96.

[0060] As shown in FIG. 5, when the length between the first connecting shaft 81 and the second connecting shaft 82 is a, the length between the first connecting shaft 81 and the sixth connecting shaft 86 is b, the length between the second connecting shaft 82 and the eighth connecting shaft 88 is c, and the angle between the line segment connecting the first connecting shaft 81 and the eighth connecting shaft 88 and the line segment connecting the first connecting shaft 81 and the sixth connecting shaft 86 is θ, the length l of the elastic part 64 represented by the length between the eighth connecting shaft 88 and the sixth connecting shaft 86 is l represented by the following formula (1) 2 which is obtained as the square root of. l 2 =a 2 +b 2 +c 2 -2ba cosθ - 2bc sinθ ···(1)

[0061] (Function and Effect of the Upper Arm Movement Assistance Device) The function and effect of the upper arm movement assistance device 1 will be described with reference to FIGS. 6 to 9. In FIGS. 6 to 9, in order to avoid complication of the drawing, the upper arm movement assistance device 1 is shown in a simplified manner, and illustrations of the second cylinder body 15, the elastic part 64, the band 53, etc. are omitted.

[0062] As shown in FIG. 6, a pair of shoulder belts 12 of the trunk mounting part 2 are mounted on both shoulders of the user H, a waist belt 11 is mounted on the waist of the user H, and the left and right upper arm mounting parts 3 are respectively mounted on the left and right upper arms HA of the user H. Thereby, the upper arm movement assistance device 1 is mounted on the back of the user H.

[0063] The remote center of motion 5 of the RCM mechanism 4 is adjusted to the position of the shoulder joint of the user H wearing the upper arm motion assist device 1. Specifically, by adjusting the vertical position of the first cylinder 14 with respect to the frame 13, the left - right position of the first cylinder 14 with respect to the frame 13, the left - right position of the shaft portion 61 with respect to the first cylinder 14, and the angle θ1 of the second central axis 60 of the shaft portion 61 with respect to the vertical line V, the remote center of motion 5 can be arranged at the position of the shoulder joint of the user H.

[0064] When the user H lowers the upper arm HA in the vertical direction, the upper arm motion assist device 1 is in a state where the parallel link portion 63 of the RCM mechanism 4 is folded. The first central axis 50 of the main body 51 coincides with the vertical line V. That is, the angle θ2 (not shown) of the first central axis 50 with respect to the vertical line V is 0°. The virtual line 90 passing through the remote center of motion 5 and orthogonal to the first central axis 50 and the second central axis 60 extends in the depth direction of the paper surface in FIG. 6.

[0065] As shown in FIG. 7, when the user H performs an operation of lifting the upper arm HA forward (also referred to as a flexion operation), the upper arm motion assist device 1 extends the parallel link portion 63. Specifically, the first link 71 rotates counterclockwise about the central axis of the first connecting shaft 81, the second link 72 rotates counterclockwise about the central axis of the second connecting shaft 82, the third link 73 rotates clockwise about the central axis of the third connecting shaft 83, and the fourth link 74 rotates clockwise about the central axis of the fourth connecting shaft 84. The elastic portion 64 (not shown) presses the sixth connecting shaft 86. The upper arm motion assist device 1 generates an auxiliary torque counterclockwise around the virtual line 90 by the elastic portion 64 pressing the sixth connecting shaft 86, and extends the parallel link portion 63, so that the folded parallel link portion 63 unfolds forward and presses the upper arm mounting portion 3, assisting the operation of raising the upper arm HA. In FIG. 7, the angle θ2 of the first central axis 50 with respect to the vertical line V is 60°.

[0066] As shown in Fig. 8, when the user H further raises the upper arm HA, the upper arm motion assisting device 1 presses the upper arm mounting portion 3 by further extending the parallel link portion 63 to assist the motion of raising the upper arm HA. In Fig. 8, the angle θ2 of the first central axis 50 with respect to the vertical line V is 90°.

[0067] As shown in Fig. 9, when the user H further raises the upper arm HA, the upper arm motion assisting device 1 presses the upper arm mounting portion 3 by further extending the parallel link portion 63 to assist the motion of raising the upper arm HA. In Fig. 9, the angle θ2 of the first central axis 50 with respect to the vertical line V is 110°.

[0068] When the upper arm motion assisting device 1 performs the bending motion of the upper arm HA, it assists the bending motion within the range where the angle θ2 of the first central axis 50 with respect to the vertical line V is 0° to 110°. When the user H maintains the upper arm HA in a raised state, the upper arm motion assisting device 1 maintains the assisting torque generated around the virtual line 90 and supports the upper arm HA from below.

[0069] When the upper arm motion assisting device 1 performs an operation of lifting the upper arm HA laterally away from the torso HB (also referred to as an abduction motion), the parallel link portion 63 rotates about the second central axis 60 of the shaft portion 61 via the first rotating portion 62a and the second rotating portion 62b. When the abduction motion of the upper arm HA is performed by the upper arm motion assisting device 1, for example, when viewing the user H from the front, it assists the abduction motion within the range where the angle of the first central axis 50 with respect to the vertical line V is 0° to 115°.

[0070] As described above, the upper arm motion assisting device 1 has an RCM mechanism 4 having a remote center of motion 5 disposed at the position of the shoulder joint of the user H. The RCM mechanism 4 rotates following the motion of the upper arm HA of the user H around the remote center of motion 5, and presses the upper arm HA via the upper arm mounting portion 3, thereby realizing a configuration that does not cover the side and front of the shoulder of the user H. Since the motion of the shoulder of the user H is not inhibited, a decrease in the degree of freedom of movement of the upper arm HA can be suppressed, and the motion of the upper arm HA can be assisted.

[0071] The upper arm motion assisting device 1 is configured not to cover the side and front of the shoulder of the user H, thereby suppressing contact between the user H and an object or contact between the user H and a person, and improving the safety of the work.

[0072] The upper arm motion assisting device 1 has an elastic part 64 that extends the telescopic parallel link part 63, and can apply an assisting force that cancels out the weight of the upper arm HA of the user H to the parallel link part 63. For this reason, the upper arm motion assisting device 1 is particularly effective when the user H lifts the upper arm HA, maintains the posture of lifting the upper arm HA, or lowers the upper arm HA while holding an object.

[0073] The shaft part 61 of the upper arm motion assisting device 1 is fixed to the first cylindrical body 14 and the second cylindrical body 15. The second cylindrical body 15 is disposed below the first cylindrical body 14 and prevents the rotation of the shaft part 61 about the central axis of the first cylindrical body 14. The upper arm motion assisting device 1 can prevent the displacement of the position of the remote motion center 5 with respect to the position of the shoulder joint of the user H even when the user H lifts a heavy object.

[0074] Since the elastic part 64 of the upper arm motion assisting device 1 is constituted by a gas spring, weight reduction and reduction of manufacturing costs can be achieved.

[0075] (Configuration of the upper arm motion assisting device according to the modification example) In the upper arm motion assisting device 1 according to the above embodiment, the body mounting part 2 has the first cylindrical body 14 and the second cylindrical body 15, but the body mounting part 2 may be configured not to have the second cylindrical body 15. The configuration of the upper arm motion assisting device according to the modification example will be described below. Note that the same or equivalent components and members as those in the above embodiment are denoted by the same reference numerals and the description thereof is omitted.

[0076] FIG. 10 is a rear perspective view of the upper arm motion assisting device 101 according to the modified example. As shown in FIG. 10, the upper arm motion assisting device 101 has a body mounting portion 102 instead of the body mounting portion 2 of the above embodiment. The body mounting portion 102 includes a waist belt 11 (not shown), a pair of shoulder belts 12 (not shown), a frame 13, and a first cylindrical body 14. The body mounting portion 102 is different from the body mounting portion 2 of the above embodiment in that it does not have a second cylindrical body 15. The shaft portion 61 is fixed to the first cylindrical body 14 by a first clamp 66.

[0077] The upper arm motion assisting device 101 has an RCM mechanism 4 having a remote motion center 5 disposed at the position of the shoulder joint of the user H. The RCM mechanism 4 rotates following the motion of the upper arm HA of the user H around the remote motion center 5 and presses the upper arm HA via the upper arm mounting portion 3, thereby realizing a configuration that does not cover the side and front of the shoulder of the user H. Since the movement of the shoulder of the user H is not hindered, a decrease in the degree of freedom of movement of the upper arm HA can be suppressed, and the movement of the upper arm HA can be assisted.

[0078] Since the upper arm motion assisting device 101 does not have the second cylindrical body 15 as shown in FIG. 10, the second left fixing portion 33, the second right fixing portion 34, and the second clamp 67 are unnecessary. Compared with the upper arm motion assisting device 1 according to the above embodiment, the upper arm motion assisting device 101 can reduce the manufacturing cost, weight, size, and burden on the user H.

[0079] The present invention is not limited to the above embodiment and modified example, and can be appropriately changed without departing from the spirit of the present invention.

[0080] In the above embodiment and modified example, a pair of RCM mechanisms 4 for assisting the movement of the left and right upper arms HA of the user H are provided, but the present invention is not limited to this, and only one of the pair of RCM mechanisms 4 may be provided.

[0081] The elastic portion 64 is configured as a gas spring in the above embodiment and modified example, but is not limited thereto. For example, the elastic portion 64 may be configured as a compression spring, a linear actuator, or the like.

[0082] In the above-described embodiment and modification, the elastic portion 64 is configured to extend the parallel link portion 63 by extending in a direction in which the other end moves away from one end. However, the present invention is not limited to this. The elastic portion may be configured to contract the parallel link portion 63 by contracting in a direction in which the other end approaches one end. The elastic portion that contracts in a direction in which the other end approaches one end is composed of, for example, an artificial muscle, a tension spring, a linear actuator, or the like. Such an elastic portion has one end rotatably connected to the first connection shaft 81 and the other end rotatably connected to the fifth connection shaft 85. The elastic portion pulls the fifth connection shaft 85 in a direction in which the other end approaches one end. When the elastic portion pulls the fifth connection shaft 85, the parallel link portion 63 contracts. The direction in which the other end of the elastic portion approaches one end is the direction in which the parallel link portion 63 contracts. The force with which the elastic portion contracts the parallel link portion 63 is a force that cancels the weight of the upper arm HA and assists the operation of raising the upper arm HA, that is, an assisting force. By pulling the fifth connection shaft 85, the elastic portion generates an assisting torque counterclockwise around the virtual line 90 (see FIG. 4). Due to the assisting torque generated by the elastic portion, the parallel link portion 63 is contracted, and the upper arm mounting portion 3 is pressed by the parallel link portion 63 that expands forward, assisting the operation of raising the upper arm HA.

[0083] In the above-described embodiment and modification, one end of the elastic portion 64 is rotatably connected to the eighth connection shaft 88 and the other end is rotatably connected to the sixth connection shaft 86. However, the present invention is not limited to this. One end of the elastic portion 64 may be rotatably connected to the second connection shaft 82. The other end of the elastic portion 64 may be rotatably connected to the seventh connection shaft 87.

[0084] In the above-described embodiments and modifications, the first cylindrical body 14 is fixed to the left frame 23 and the right frame 24 via the first left fixing portion 31 and the first right fixing portion 32, but the present invention is not limited thereto. The first cylindrical body 14 may be configured to be swingably supported with respect to the left frame 23 and the right frame 24 in the vertical direction, the left-right direction, and the front-back direction. For example, a swing member for swingably supporting the first cylindrical body 14 may be provided between the first left fixing portion 31 and the first cylindrical body 14, and between the first right fixing portion 32 and the first cylindrical body 14. The swing member may be composed of an elastic member such as a spring, for example.

[0085] In the above-described embodiment, the second cylindrical body 15 is fixed to the left frame 23 and the right frame 24 via the second left fixing portion 33 and the second right fixing portion 34, but the present invention is not limited thereto. The second cylindrical body 15 may be configured to be swingably supported with respect to the left frame 23 and the right frame 24 in the vertical direction, the left-right direction, and the front-back direction. For example, a swing member for swingably supporting the second cylindrical body 15 may be provided between the second left fixing portion 33 and the second cylindrical body 15, and between the second right fixing portion 34 and the second cylindrical body 15. The swing member may be composed of an elastic member such as a spring, for example.

[0086] In the above-described embodiments and modifications, the rotating portion 62 is composed of two members, the first rotating portion 62a and the second rotating portion 62b, but the present invention is not limited thereto, and it may be composed of one member. When the rotating portion 62 is composed of one member, the first link 71 may be connected to the rotating portion 62 via the first connecting shaft 81, and the second link 72 may be connected to the rotating portion 62 via the second connecting shaft 82.

Explanation of Reference Numerals

[0087] 1,101 Upper Arm Motion Assist Device 2,102 Torso Mounting Portion 3 Upper Arm Mounting Portion 4 Remote Center of Motion Mechanism (RCM Mechanism) 5 Remote Center of Motion 11 Waist Belt 12 Pair of Shoulder Belts 13 Frame 14 The first cylinder 15 The second cylinder 50 The first central axis 51 The main body 60 The second central axis 61 The shaft part 62 The rotating part 63 The parallel link part 64 The elastic part 71 The first link 72 The second link 73 The third link 74 The fourth link 81 The first connecting shaft 82 The second connecting shaft 83 The third connecting shaft 84 The fourth connecting shaft 85 The fifth connecting shaft 86 The sixth connecting shaft 87 The seventh connecting shaft

Claims

1. An upper arm movement assist device that is worn by a user and assists movement of the user's upper arm, A torso attachment part that is detachably attached to the torso of the user; an upper arm attachment part that is detachably attached to the upper arm; a remote motion center mechanism provided between the torso attachment part and the upper arm attachment part; Equipped with The remote motion center mechanism has a remote motion center arranged at the position of the user's shoulder joint, rotates around the remote motion center in response to the movement of the upper arm, and presses against the upper arm via the upper arm attachment part.

2. the upper arm attachment portion has a semi-cylindrical main body on which the upper arm is placed, the remote motion center mechanism has a shaft portion fixed to the torso attachment portion, The body has a first central axis. The shaft portion has a second central axis. The upper arm action assist device according to claim 1 , wherein a point where the first central axis and the second central axis intersect constitutes the remote motion center.

3. The remote motion center mechanism includes: a rotating portion provided to be rotatable about the second central axis with respect to the shaft portion; An expandable parallel link portion provided on the rotating portion; The upper arm movement assist device according to claim 2 , further comprising an elastic portion that extends or contracts the parallel link portion.

4. The torso attachment portion is A waist belt that is worn by wrapping around the waist of the user; A pair of shoulder belts that are wrapped around the left and right shoulders of the user, respectively; a frame that is disposed on the back of the user and connects the waist belt and the pair of shoulder belts; a first cylinder fixed to the frame and protruding from the frame in the left-right direction; The upper arm movement assist device according to claim 3 , wherein the shaft portion is fixed to the first cylinder body.

5. the torso attachment portion has a second cylinder that is fixed to the frame below the first cylinder and protrudes from the frame in the left-right direction, The upper arm action assist device according to claim 4 , wherein the shaft portion is fixed to the first cylinder body and the second cylinder body.

6. The parallel link portion is A first link; A second link disposed in parallel with the first link; a third link disposed across the first link; A fourth link disposed in parallel with the third link; a first connecting shaft that connects one end of the first link and the rotating portion so as to be capable of relative rotation; a second connecting shaft that connects one end of the second link and the rotating portion so as to be capable of relative rotation; a third connecting shaft that connects one end of the third link and the main body so as to be capable of rotating relative to one another; a fourth connecting shaft that connects one end of the fourth link and the main body so as to be capable of rotating relative to one another; a fifth connecting shaft that connects the other end of the second link and the other end of the third link so as to be capable of rotating relative to each other; a sixth connecting shaft that connects the other end of the first link and the other end of the fourth link so as to be capable of rotating relative to each other; 4. The upper arm action assist device according to claim 3, further comprising a seventh connecting shaft that connects an intermediate portion between the one end and the other end of the first link and an intermediate portion between the one end and the other end of the third link so as to be capable of relative rotation.

7. 4. The upper arm movement assist device according to claim 3, wherein the elastic portion is formed of a gas spring.

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