Self-weight compensation mechanism and human body support device

Abstract

To provide a self-weight compensation mechanism capable of changing compensation force.SOLUTION: A self-weight compensation mechanism 1 includes: a base 2; a first rotary member 3 rotatable relative to the base 2; a second rotary member 4 rotatable relative to the base 2 and the first rotary member 3; an energization part 5 for energizing the first rotary member 3 according to a rotation angle of the first rotary member 3 relative to the second rotary member 4; and a restraining part 6 that restrains the second rotary member 4 at a prescribed rotation position relative to the base 2 until prescribed conditions are met.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a self-weight compensation mechanism.

Background Art

[0002] Self-weight compensation mechanisms that can compensate for the self-weight of movable parts such as the arm part of a device and the self-weight of a human arm are known (see, for example, Patent Documents 1 to 4 and Non-Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

[0005] A weight compensation mechanism can be useful if the compensation force can be adjusted.

[0006] Therefore, the object of the present invention is to provide a self-weight compensation mechanism that can change the compensation force. [Means for solving the problem]

[0007] The self-weight compensation mechanism of the present invention comprises a base, a first rotating member rotatable with respect to the base, a second rotating member rotatable with respect to the base and the first rotating member, a biasing unit that biases the first rotating member according to the rotation angle of the first rotating member with respect to the second rotating member, and a restraining unit that restrains the second rotating member to a predetermined rotation position with respect to the base until predetermined conditions are met.

[0008] In the above configuration, the self-weight compensation mechanism of the present invention is preferably a self-weight compensation mechanism in which the restraint by the restraint portion is released when the first rotating member rotates to a predetermined angle relative to the second rotating member.

[0009] In the above configuration, the self-weight compensation mechanism of the present invention is preferably a self-weight compensation mechanism in which the restraint by the restraint portion is released when the second rotating member applies a torque exceeding a predetermined value to the base.

[0010] In the above configuration, the self-weight compensation mechanism of the present invention is preferably a self-weight compensation mechanism in which the restraining part has an operating part that is held on the second rotating member or the base so as to be operable between a restraining position in which restraint is performed by the restraining part and a release position in which the restraining by the restraining part is released.

[0011] In the above configuration, the self-weight compensation mechanism of the present invention is preferably a self-weight compensation mechanism having a connecting member that connects the first rotating member and the operating part such that the operating part moves from the restrained position to the released position when the first rotating member rotates to a predetermined angle relative to the second rotating member.

[0012] The human body support device of the present invention preferably comprises the self-weight compensation mechanism and a mounting portion that attaches the base to the torso so that the arm can be supported by the first rotating member. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a self-weight compensation mechanism that can change the compensation force. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing the self-weight compensation mechanism of one embodiment of the present invention. [Figure 2] This figure shows the state after the first rotating member has been rotated further downward from the state shown in Figure 1. [Figure 3] Figure 2 shows the state after the first rotating member has been rotated further downward from the state shown, releasing the restraint by the restraining part. [Figure 4] Figure 3 shows the state when the second rotating member rotates downward from the state shown in Figure 3, and the compensating force by the biasing part decreases. [Figure 5] This is a schematic diagram showing an example of a connecting member that connects the first rotating member and the operating part of the restraining part. [Modes for carrying out the invention]

[0015] Hereinafter, embodiments of the present invention will be illustrated and described with reference to the drawings.

[0016] As shown in FIGS. 1 to 2, in one embodiment of the present invention, the self-weight compensation mechanism 1 includes a base 2, a first rotating member 3, a second rotating member 4, a biasing portion 5, and a restraining portion 6. The biasing portion 5 includes a rocking slider link 9 composed of a first slider 7 and a second slider 8, and a spring S. The restraining portion 6 includes an operating portion 10, a fixed portion 11, and a stopper 12.

[0017] The base 2 is attached to the attachment portion 13. When the self-weight compensation mechanism 1 is used to compensate for the self-weight of a movable portion such as an arm portion of a device, for example, the movable portion can be constituted by the first rotating member 3, and the attachment portion 13 can constitute the main body portion of the device. Also, instead of constituting the movable portion by the first rotating member 3, it may be configured such that the movable portion can be supported by the first rotating member 3. When the self-weight compensation mechanism 1 is used to compensate for the self-weight of a human arm, for example, the attachment portion 13 may be configured to attach the base 2 to the torso so that the arm can be supported by the first rotating member 3.

[0018] The first rotating member 3 is rotatable about a first rotation axis O1 with respect to the base 2. The self-weight compensation mechanism 1 can generate a self-weight compensation force (also simply referred to as a compensation force) by arranging the first rotation axis O1 non-vertically, that is, in a direction other than the vertical direction, for example, extending along the horizontal direction as shown in the drawing.

[0019] The first rotating member 3 is connected to the base 2 so as to be rotatable about the first rotation axis O1 via a first rotation center portion C1. Note that the first rotation center portion C1 is not limited to a configuration in which the first rotating member 3 and the base 2 are connected via a shaft body (for example, it may be configured to be connected via an elastically deformable elastic portion).

[0020] The first rotating member 3 has a first link portion 3a extending radially from the first rotation center C1. The first link portion 3a is pivotable vertically upward (also simply called upward) and vertically downward (also simply called downward) around the first rotation axis O1. The first link tip 3b, which is the radially outer end of the first link portion 3a, moves upward as the first link portion 3a pivots upward, and moves downward as the first link portion 3a pivots downward.

[0021] The second rotating member 4 is rotatable around the second rotation axis O2 relative to the base 2 and the first rotating member 3. The second rotation axis O2 preferably coincides with the first rotation axis O1, but its position or orientation may differ as long as the effects of the present invention are obtained.

[0022] The second rotating member 4 is connected to the base 2 so as to be rotatable around the second rotation axis O2 via the second rotation center C2. The second rotation center C2 is not limited to a configuration in which the second rotating member 4 and the base 2 are connected via an axle. Alternatively, instead of connecting the second rotating member 4 to the base 2 so as to be rotatable around the second rotation axis O2, the second rotating member 4 may be connected to the first rotating member 3 so as to be rotatable around the second rotation axis O2 (for example, in the vicinity of the first rotation center C1).

[0023] The second rotating member 4 has a second link portion 4a that extends radially upward from the second rotation center C2. The second link portion 4a is pivotable around the second rotation axis O2.

[0024] The biasing unit 5 applies a biasing force to the first rotating member 3 in a direction that reduces the rotation angle, which increases as the rotation angle of the first rotating member 3 relative to the second rotating member 4 increases. More specifically, the biasing unit 5 applies a biasing force to the first rotating member 3 in a direction that reduces the rotation angle θ, which increases as the rotation angle θ of the first link portion 3a relative to the second rotating member 4 downwards from a predetermined position A (e.g., upper limit position) increases.

[0025] The biasing section 5 includes a swing slider link 9 composed of a first slider 7 and a second slider 8 that are slidable relative to each other, and a spring S that generates the biasing force. The spring S is provided between the first slider 7 and the second slider 8 so as to bias the first slider 7 and the second slider 8 in a direction that causes them to slide relative to each other.

[0026] The first slider 7 is connected to the first rotating member 3 so as to be rotatable around the third rotating axis O3 via the third rotating center C3. The third rotating center C3 is not limited to a configuration in which the first slider 7 and the first rotating member 3 are connected via an axis. The third rotating axis O3 is preferably parallel to the first rotating axis O1, but its orientation may differ as long as the effects of the present invention can be obtained.

[0027] The third rotation center C3 is provided between the first rotation axis O1 and the tip of the first link 3b in the radial direction of the first rotation axis O1, but is not limited to this. For example, the first rotation member 3 may be provided with other link parts in addition to the first link part 3a, extending from the first rotation center C1 to the opposite side of the first link part 3a, and the third rotation center C3 may be provided on the other link part.

[0028] The second slider 8 is connected to the second rotating member 4 so as to be rotatable around the fourth rotating axis O4 via the fourth rotating center C4. The fourth rotating center C4 is not limited to a configuration in which the second slider 8 and the second rotating member 4 are connected via an axis. The fourth rotating axis O4 is preferably parallel to the second rotating axis O2, but its orientation may differ as long as the effects of the present invention can be obtained.

[0029] The fourth pivot center C4 is provided in the radial direction of the second pivot axis O2, between the second pivot axis O2 and the second link tip 4b, which is the radially outer end of the second link portion 4a, but is not limited to this. For example, the second pivot member 4 may be provided with other link portions in addition to the second link portion 4a, extending from the second pivot center C2 to the opposite side of the second link portion 4a, and the fourth pivot center C4 may be provided on these other link portions.

[0030] The second slider 8 has a slider link portion 9a that extends radially from the fourth rotation center C4. The slider link portion 9a is pivotable around the fourth rotation axis O4.

[0031] The first slider 7 has a retaining portion 9c that holds the slider link portion 9a so as to be slidable along the slider axis X, which passes through the fourth pivoting center C4 and the slider link tip 9b, which is the radially outer end of the slider link portion 9a.

[0032] The slider link portion 9a has a screw-fastened portion 9d on the side of the slider link tip 9b that is closer to the holding portion 9c. The spring S is compressible by the holding portion 9c and the screw-fastened portion 9d and is configured as a compression spring that generates a biasing force according to the amount of compression (for example, with a predetermined spring constant). Alternatively, the screw-fastened portion 9d may be provided on the slider link portion 9a on the side of the fourth rotation center C4 that is closer to the holding portion 9c, and the spring S may be configured as a tension spring that is stretchable by the holding portion 9c and the screw-fastened portion 9d and generates a biasing force according to the amount of tension (for example, with a predetermined spring constant).

[0033] Instead of providing a slider link portion 9a on the second slider 8 and a holding portion 9c on the first slider 7, a configuration in which the holding portion 9c is provided on the second slider 8 and the slider link portion 9a is provided on the first slider 7 may be used.

[0034] As shown in Figures 1 to 4, the restraining part 6 restrains the second rotating member 4 to the base part 2 at a predetermined rotational position (also called the initial position) shown in Figure 1 until predetermined conditions are met.

[0035] The predetermined conditions are not particularly limited, but for example, they may be a state in which the user operates the restraint part 6 to release the restraint, or they may be predetermined operating conditions of the self-weight compensation mechanism 1. The predetermined operating conditions may be, for example, a state in which the first rotating member 3 has rotated to a predetermined angle relative to the second rotating member 4 (for example, a state in which the rotation angle θ of the first link part 3a relative to the second rotating member 4 from a predetermined position A downwards becomes a limit angle θ1 which is a predetermined angle downwards from the predetermined position A), or a state in which the second rotating member 4 has applied a torque exceeding a predetermined value to the base part 2.

[0036] With such a restraining part 6, by performing a release operation to bring the system under predetermined conditions as needed, the restraint by the restraining part 6 can be released, thereby freeing the second rotating member 4 from its initial position, i.e., allowing the second link part 4a to swing downward, and thereby reducing the compensating force (for example, to zero).

[0037] In particular, if the constraint by the restraining part 6 is set to be released when the first rotating member 3 rotates to a predetermined angle relative to the second rotating member 4, then it is convenient because the restraining by the restraining part 6 can be released and the compensating force reduced simply by rotating the first rotating member 3 to a predetermined angle relative to the second rotating member 4, without requiring any special release operation.

[0038] The restraint unit 6 has an operating unit 10 and a fixed unit 11. The operating unit 10 is held on the second rotating member 4 so as to be movable between a restrained position where restraint is performed by the restraint unit 6 and a released position where the restraint by the restraint unit 6 is released. The fixed unit 11 is provided on the base 2 in a non-movable manner. The restraint unit 6 performs restraint through the cooperation of the operating unit 10 and the fixed unit 11, and releases the restraint by releasing the cooperation between the operating unit 10 and the fixed unit 11.

[0039] More specifically, the operating part 10 is connected to the second rotating member 4 so as to be rotatable around the fifth rotating axis O5 via the fifth rotating center C5. Note that the fifth rotating center C5 is not limited to a configuration in which the operating part 10 and the second rotating member 4 are connected via a shaft.

[0040] The operating part 10 has a hook 10a that extends radially from the fifth rotation center C5 and whose radially outer end is bent downward. The hook 10a is pivotable upward and downward around the fifth rotation axis O5. The hook tip 10b, which is the radially outer end of the hook 10a, moves upward as the hook 10a pivots upward and moves downward as the hook 10a pivots downward. The hook 10a has a restrained position in which the hook tip 10b engages with the immovable part 11, Detention It is positioned above the fixed position and is rotatable between the release position where the hook tip 10b moves away from the fixed part 11.

[0041] The hook 10a is biased by a spring (not shown) in the direction from the released position toward the restrained position. This biasing force causes it to rotate until it contacts the anti-rotation stopper 12 at or slightly beyond the restrained position, as shown in Figure 4, when it is in the released position as shown in Figure 3. The anti-rotation stopper 12 is provided on the second rotating member 4 in a non-operational manner. Note that a configuration without such a spring and anti-rotation stopper 12 is also possible.

[0042] The inclination angle of at least one of the interlocking surfaces 10c of the interlocking hook tip 10b and the interlocking surface 11a of the immovable part 11 can be set such that when the second rotating member 4 applies a torque exceeding a predetermined value to the base 2, the hook 10a rotates, and as a result, the restraint by the restraint part 6 is released. With this setting, the restraint by the restraint part 6 can be released and the compensating force reduced simply by rotating the first rotating member 3 to a predetermined angle relative to the second rotating member 4, without requiring any special release operation.

[0043] The operating part 10 is not limited to a rotatable hook 10a, but may also be composed of, for example, a sliding latch. The operating part 10 and the stationary part 11 are not limited to the above configuration, but may also be composed of, for example, magnets that attract each other.

[0044] As shown in Figure 5, a connecting member 14 may be provided to connect the first rotating member 3 and the operating part 10 so that the operating part 10 (for example, a hook 10a, a latch, or a magnet) moves from the restrained position to the release position when the first rotating member 3 rotates to a predetermined angle relative to the second rotating member 4. The connecting member 14 is preferably made of a tension member such as a string or belt, as shown in the figure. In this case, for example, the connecting member 14 can connect the first link part 3a and the hook 10a. The connecting member 14 may also be made of a rigid member. The connecting member 14 suppresses the unexpected release of the restraint by the restraint part 6 and enables stable release operation.

[0045] The restraining part 6 may be configured such that the operating part 10 is provided on the base 2 and the restraining part 11 is provided on the second rotating member 4, instead of the configuration in which the operating part 10 is provided on the second rotating member 4 and the restraining part 11 is provided on the base 2.

[0046] Note that the restraining part 6 is not limited to a configuration having an operating part 10 and a non-moving part 11. For example, the restraining part 6 may be provided on the second rotating member 4 in a way that prevents it from moving. Ta It may also consist of a first magnet and a second magnet that is inoperable and provided on the base 2 to attract the first magnet.

[0047] The present invention is not limited to the embodiments described above, and can be modified in various ways without departing from its essence.

[0048] Therefore, the self-weight compensation mechanism 1 of the above-described embodiment can be modified as long as it comprises a base 2, a first rotating member 3 rotatable relative to the base 2, a second rotating member 4 rotatable relative to the base 2 and the first rotating member 3, a biasing unit 5 that biases the first rotating member 3 according to the rotation angle of the first rotating member 3 relative to the second rotating member 4, and a restraining unit 6 that restrains the second rotating member 4 to a predetermined rotation position relative to the base 2 until predetermined conditions are met.

[0049] For example, the second link portion 4a is not limited to a configuration that extends upward from the second pivot center C2, but may also be configured to extend downward from the second pivot center C2. The spring S is not limited to a compression spring or a tension spring, but may also be composed of, for example, an air spring or a magnetic spring. Furthermore, the spring S is not limited to a spring that generates a biasing force according to the amount of displacement, but may also be composed of, for example, a constant-load spring that generates a substantially constant biasing force regardless of the amount of displacement. Also, the biasing portion 5 is not limited to a configuration that has a swing slider link 9. The self-weight compensation mechanism 1 may have, for example, a further link member that is rotatably connected to the tip 3b of the first link.

[0050] In addition, it is preferable that the self-weight compensation mechanism 1 of the embodiment described above is a self-weight compensation mechanism 1 in which the restraint by the restraint part 6 is released when the first rotating member 3 rotates to a predetermined angle relative to the second rotating member 4.

[0051] In the above-described embodiment, it is preferable that the self-weight compensation mechanism 1 is such that, in the above configuration, the restraint by the restraint portion 6 is released when the second rotating member 4 applies a torque exceeding a predetermined value to the base portion 2.

[0052] In the above-described embodiment, the self-weight compensation mechanism 1 is preferably a self-weight compensation mechanism 1 in which the restraining part 6 has an operating part 10 that is held on the second rotating member 4 or the base 2 so as to be operable between a restraining position in which restraint is performed by the restraining part 6 and a release position in which the restraining by the restraining part 6 is released.

[0053] In the above-described embodiment, the self-weight compensation mechanism 1 is preferably a self-weight compensation mechanism 1 that has a connecting member 14 that connects the first rotating member 3 and the operating part 10 so that the operating part 10 moves from a restrained position to a released position when the first rotating member 3 rotates to a predetermined angle relative to the second rotating member 4. [Explanation of Symbols]

[0054] 1 Dead weight compensation mechanism 2 base 3. First moving member 3a First Link Section 3b First link tip 4. Second moving member 4a Second Link Section 4b Second Link Tip 5. Biasing section 6 Restraint part 7. First slider 8. Second slider 9. Oscillating slider link 9a Slider link section 9b Slider link tip 9c Holding part 9d Screw fastening part 10. Operating part 10a hook 10b Hook tip 10c The mating surface at the tip of the hook 11. Immovable parts 11a Engagement surface of the immovable part 12. Anti-rotation device 13 Mounting part 14 Connecting members A Predetermined position C1 First rotation center C2 Second Phase Center C3 Third Movement Center C4 4th Movement Center C5 5th Movement Center O1 First Axis Line O2 Second Axis Line O3 Third Axis Line O4 4th Moving Axis Line O5 5th Axis Line S spring X slider axis θ Rotation angle θ1 Limit angle

Claims

1. The base and, A first rotating member that is rotatable relative to the base, The base portion and the second rotating member which is rotatable relative to the first rotating member, A biasing unit that biases the first rotating member according to the rotation angle of the first rotating member relative to the second rotating member, It includes a restraining part that restrains the second rotating member to a predetermined rotational position relative to the base until predetermined conditions are met, The first rotating member is a self-weight compensation mechanism in which the restraining portion is rotatable relative to the second rotating member while the restraining portion restrains the second rotating member to the predetermined rotational position.

2. The self-weight compensation mechanism according to claim 1, wherein the restraint by the restraint portion is released when the first rotating member rotates to a predetermined angle relative to the second rotating member.

3. The self-weight compensation mechanism according to claim 1 or 2, wherein the restraint by the restraint portion is released when the second rotating member applies a torque exceeding a predetermined value to the base.

4. The self-weight compensation mechanism according to any one of claims 1 to 3, wherein the restraining part has an operating part that is held on the second rotating member or the base so as to be operable between a restraining position in which restraint is performed by the restraining part and a release position in which the restraining by the restraining part is released.

5. The self-weight compensation mechanism according to claim 4, further comprising a connecting member that connects the first rotating member and the operating part, such that the operating part moves from the restrained position to the released position when the first rotating member rotates to a predetermined angle relative to the second rotating member.

6. A human body support device comprising a self-weight compensation mechanism according to any one of claims 1 to 5, and a mounting part for attaching the base to the torso so that the arm can be supported by the first rotating member.

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