Deadweight compensation device

Abstract

To make a weight compensation force adjustable in accordance with weight of different supported bodies without preparing a plurality of weights extra as spare for adjustment.SOLUTION: A self-weight compensator includes: a first arm which rotatably supports a support point between a first end and a second end; a first weight supported at the first end of the first arm; a second arm which is rotatably supported at the support point independently of the first arm and extends from the support point; a second weight supported by the second arm; a support arm which is connected to the first arm at the second end, extends opposite the direction in which the second arm extends, and is capable of supporting a supported body; an interlock mechanism interlocking the support arm and the second arm so that they are parallel to each other; a first position adjustment part capable of adjusting a position of the first weight with respect to the support point; and a second position adjustment part capable of adjusting a position of the second weight with respect to the support point.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a weight compensation device. [Background technology]

[0002] In recent years, automation using machines and robots and a reduction in the number of workers have been promoted at manufacturing sites, but it is difficult to completely eliminate manual work. One type of manual work is work in which workers handle heavy tools. This type of work is a major obstacle to improving work efficiency. A weight compensation device is a mechanism for compensating for the weight of such heavy tools (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a weight compensation device having a first arm element and a second arm element formed by extending two links of a pantograph-type link structure mounted on an autonomous vehicle, a working tool detachably attached to a hand at the tip of the first arm element, and a counter weight attached to the tip of the second arm element to provide a weight compensation function. By using a weight compensation device configured in this way, it becomes possible to compensate for the weight of the tool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-291215 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of the weight compensation device disclosed in Patent Document 1, when the working tool attached to the hand is brought close to the fulcrum of the pantograph-type link structure, the connection part connecting the two upper links out of the four links is far away from the fulcrum. Therefore, it is necessary to secure a large occupied space necessary for the pantograph-type link structure to operate. In addition, the mass of the counter weight, which is a weight, needs to be adjusted according to the mass of the working tool to be lifted. Therefore, it is necessary to prepare many spare weights.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a weight compensation device that can adjust the weight compensation force according to the masses of different supported objects without the need to prepare multiple extra weights as reserves for adjustment. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure provides a weight compensation device, comprising: a first arm having a first end and a second end, the first end and the second end being rotatably supported at a support point between the first end and the second end; cormoranta first weight supported by the first arm at a position spaced apart in the extending direction of the first arm as described above, a second arm supported at the supporting point so as to be rotatable independently of the first arm and extending from the supporting point in a direction intersecting the extending direction of the first arm, a second weight supported by the second arm at a position spaced apart from the supporting point in the extending direction of the second arm, a support arm rotatably connected to the first arm at the second end and extending in a direction parallel to and opposite to the extending direction of the second arm so as to be able to support a supported object, an interlocking mechanism which interlocks the operations of the support arm and the second arm so that they are always parallel to each other, and a linking mechanism which links the operations of the support arm and the second arm so that the second end, the supporting point, and the first end the second arm is rotatable independently with respect to the first arm about a first axis line passing through the support point, and the support arm is rotatable with respect to the first arm about a second axis line passing through the second end of the first arm and extending parallel to the first axis line. Effect of the Invention

[0008] According to the weight compensation device of the present disclosure, the weight compensation force can be adjusted in accordance with the masses of different supported objects, without the need to prepare a plurality of extra weights as reserves for adjustment. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram showing a configuration of a weight compensation device according to the first embodiment. [Diagram 2] FIG. 11 is a schematic diagram showing a configuration of a weight compensation device according to a second embodiment. [Diagram 3] FIG. 13 is a schematic diagram showing a configuration of a weight compensation device according to a third embodiment. [Figure 4]FIG. 13 is a schematic diagram showing a configuration of a weight compensation device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment for carrying out the weight compensation device 1 according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to only this embodiment.

[0011] (Configuration of the weight compensation device) A weight compensation device 1 of a first embodiment will be described with reference to Fig. 1. The weight compensation device 1 of the embodiment according to the present disclosure includes a first arm 10, a first weight 15, a second arm 20, a second weight 25, a support arm 30, an interlocking mechanism 60, a first position adjustment unit 70, and a second position adjustment unit 80.

[0012] (First arm configuration) The first arm 10 has a first end 11 and a second end 12. The first arm 10 is basically shaped to extend in a straight line from the first end 11 to the second end 12 along a first imaginary center line C1 connecting the first end 11 and the second end 12. The first imaginary center line C1 is an imaginary line connecting the center of gravity of the first weight 15 and the second end 12, and a support point 13 is present between them. In addition, in the first arm 10, the support point 13, the center of gravity of the first weight 15, and the second end 12 are all on the first imaginary center line C1, and the distance L between the support point 13 and the center of gravity of the first weight 15 is 1 / 2. a and the distance L between the support point 13 and the second end 12 1 and 12. The first arm 10 is not limited to being formed as a straight member as long as they can be kept constant. In other words, the first arm 10 may have a bent or curved shape between the first end 11 and the second end 12 as long as it extends along the first imaginary center line C1. The first arm 10 is rotatably supported at a support point 13 between the first end 11 and the second end 12.

[0013] The support point 13 is a position where the first arm 10 is supported in a rotatable state. The support point 13 is a point on the first arm 10 that is a rotation center on the first imaginary center line C1. The first arm 10 is basically rotatable around an axis perpendicular to the paper surface with the support point 13 as a reference, but may be configured to be supported rotatably around two orthogonal axes including the axis perpendicular to the paper surface and the vertical direction Dv, or all three orthogonal axes. Although omitted in FIG. 1, configurations such as a two-axis movable pan head, a three-axis movable pan head, and a ball-type pan head used in pan heads for optical instruments are considered as configurations for rotatably supporting the two orthogonal axes and for rotatably supporting the three orthogonal axes.

[0014] The first arm 10 is supported at the support point 13 in a movable state by, for example, a large moving device such as a vehicle or a small moving device such as a dolly or a support stand with casters. This moving device may be temporarily fixed in an immovable state at any position by fixing wheels or the like. This moving device may also have a member for preventing tipping over, such as an outrigger. Also, the height of the support point 13 may be adjusted by a lifting device or the like, and the first arm 10 may be supported so as to be movable in the vertical direction Dv.

[0015] (First weight composition) The first weight 15 is supported by the first arm 10 at a position spaced apart from the support point 13 toward the first end 11 in the extension direction of the first arm 10. The first weight 15 is a counterweight having a constant mass that does not fluctuate. The first weight 15 may be disposed so as to overlap with the first imaginary center line C1 at a position spaced apart from the support point 13. The first weight 15 is disposed between the support point 13 and the first end 11 or at a position overlapping with the first end 11. In this embodiment, the first weight 15 is fixed to the first end 11. Also, only one first weight 15 is disposed in this embodiment. However, in this embodiment, the mass of the first weight 15 is constant as an explanation of a configuration that allows the weight compensation force of the supported object 50 to be adjusted without changing the mass of the first weight 15, and does not limit the means of replacing the weight, increasing or decreasing the amount of liquid or powder in the weight, or adding or removing multiple weights to the position of the first weight 15.

[0016] (Second arm configuration) The second arm 20 is supported at the support point 13 so as to be rotatable independently of the first arm 10 around the first axis O1. The second arm 20 is basically connected to the first arm 10, but it does not necessarily have to be directly connected to the first arm 10 as long as it rotates around the first axis O1. The first axis O1 is a virtual line passing through the support point 13 and perpendicular to the first virtual center line C1. The second arm 20 extends in a direction intersecting the extension direction of the first arm 10 from the base end 22 located at the support point 13 to the tip 21. The second arm 20 basically has a shape extending from the support point 13 to the tip 21 in a straight line along a second virtual center line C2 intersecting the first virtual center line C1. The second virtual center line C2 is a virtual line connecting the center of gravity of the second weight 25 and the support point 13. The second imaginary center line C2 is an imaginary straight line extending in the same imaginary plane as the first imaginary center line C1 and perpendicular to the first axis O1. The second arm 20 is basically linearly extending along the second imaginary center line C2, but is not necessarily limited to being linearly formed as long as it is possible to support the second weight 25 so that the center of gravity is on the second imaginary center line C2. Therefore, the second arm 20 may be bent or curved between the base end 22 and the tip 21.

[0017] (Second weight composition) The second weight 25 is supported by the second arm 20 at a position spaced from the support point 13 in the extension direction of the second arm 20. The second weight 25 is a counterweight having a constant mass that does not fluctuate. The second weight 25 only needs to be disposed at a position spaced from the support point 13 so as to overlap with the second imaginary center line C2. Therefore, the second weight 25 is disposed between the support point 13 and the tip 21, or at a position overlapping with the tip 21. In this embodiment, the second weight 25 is fixed with respect to the tip 21. Moreover, only one second weight 25 is disposed in this embodiment. The second weight 25 has the same mass as the first weight 15. ofIt may be a counterweight, or may be a counterweight of a different mass. However, in this embodiment, the mass of the second weight 25 is fixed as an explanation of a configuration that makes it possible to adjust the weight compensation force of the supported body 50 without changing the mass of the second weight 25, and does not limit the means of replacing the weight, increasing or decreasing the amount of liquid or powder in the weight, or adding or removing multiple weights at the position of the second weight 25.

[0018] (Support arm configuration) The support arm 30 is rotatably connected to the first arm 10 at the second end 12. The support arm 30 is basically shaped to extend from the first support end 31 to the second support end 32 in a straight line along a third imaginary center line C3 connecting the first support end 31 and the second support end 32. The third imaginary center line C3 is an imaginary line connecting the second end 12 and the center of gravity of the supported object 50, and is a line that intersects with the first imaginary center line C1 and is parallel to the second imaginary center line C2. The support arm 30 is disposed so that the first support end 31 overlaps with the second end 12, and is rotatably connected to the first arm 10 around the second axis line O2. The second axis line O2 is an imaginary line that passes through the second end 12 and is perpendicular to the first imaginary center line C1 and the third imaginary center line C3. The second axis line O2 extends parallel to the first axis line O1 at the second end 12. The support arm 30 is basically linear and extends along the third imaginary center line C3, but is not necessarily limited to being linear, as long as it can support the supported object 50 so that its center of gravity is on the third imaginary center line C3. The support arm 30 may be bent or curved between the first support end 31 and the second support end 32. The support arm 30 extends in a direction opposite to the direction in which the second arm 20 extends, among directions intersecting the extending direction of the first arm 10. In other words, the direction in which the support arm 30 extends from the first support end 31 connected to the second end 12 of the first arm 10 to the second support end 32 is opposite to the direction in which the second arm 20 extends from the base end 22, which is rotatably supported by the support point 13, to the tip 21. The support arm 30 is capable of supporting the supported object 50 at the second support end 32.

[0019] (Configuration of the Supported Body) The supported object 50 is attached to the support arm 30 in a detachable state. The supported object 50 is an object that is moved while being lifted by the weight compensation device 1 against the gravity downward in the vertical direction Dv, and is any heavy object. For example, the supported object 50 can be a heavy object (e.g., heavy tools) used by workers in a factory or the like. The supported object 50 may be disposed so as to overlap with the third imaginary center line C3 at a position away from the first support end 31. Therefore, the supported object 50 is disposed between the first support end 31 and the second support end 32, or at a position overlapping with the second support end 32. In this embodiment, the supported object 50 is detachable from the second support end 32.

[0020] (Structure of interlocking mechanism) The interlocking mechanism 60 has a function of interlocking the operation of the support arm 30 and the second arm 20 so that they are always parallel to each other. That is, the second arm 20 rotates around the base end 22 while being supported by the support point 13 in response to the rotation of the support arm 30 around the support first end 31 connected to the second end 12 of the first arm 10, and the third imaginary center line C3 and the second imaginary center line C2 are always parallel to each other. Since this interlocking mechanism has a function of restricting the mutual operation so that the third imaginary center line C3 and the second imaginary center line C2 are always parallel to each other, when the second arm 20 rotates, the support arm 30 also rotates following it. The interlocking mechanism 60 of this embodiment has a first sprocket 61, a second sprocket 62, a chain 63, and a chain adjustment mechanism 64.

[0021] The first sprocket 61 is a gear having a disk shape for transmitting rotation around the second axis O2, which is the central axis of the first sprocket 61, to the chain 63 and transmitting the rotation of the chain 63 to the central axis. The first sprocket 61 is connected to the first support end 31 of the support arm 30 and is constrained so as to be synchronized with the rotation of the support arm 30. The constraining method may be, but is not limited to, a method using a key and a key groove, a method using a spline, a method using a bolt, welding, or the like. The first sprocket 61 is rotatably connected to the first arm 10. The first sprocket 61 converts the weight of the supported body 50 supported by the support arm 30 into torque around the second axis O2 through a bending moment generated inside the support arm 30, converts it into tension of the chain 63, and transmits the load. The first sprocket 61 is basically in the shape of a perfect circle, but a sprocket whose pitch diameter changes depending on the phase may be used.

[0022] The second sprocket 62 is a gear having a disk shape for transmitting rotation around the first axis O1, which is the central axis of the second sprocket 62, to the chain 63 and transmitting rotation by the chain 63 to the central axis of the second sprocket 62. The second sprocket 62 is connected to the base end 22 of the second arm 20 and is constrained so as to be synchronized with the rotation of the second arm 20. The constraining method may be, but is not limited to, a method using a key and a key groove, a method using a spline, a method using a bolt, welding, or the like. The base end 22 coincides with the support point 13 that supports the second arm 20 so as to be rotatable around the first axis O1. In other words, the second sprocket 62 is disposed at a position separated from the first sprocket 61. The second sprocket 62 is rotatable independently of the first arm 10. The second sprocket 62 converts the weight of the second weight 25 supported by the second arm 20 into torque around the first axis O1 through a bending moment generated inside the second arm 20, converts it into tension of the chain 63, and transmits the load. In this embodiment, the second sprocket 62 is basically circular, and its pitch diameter is basically configured to be equal to the pitch diameter of the first sprocket 61. However, a sprocket whose pitch diameter changes depending on the phase may also be used. In that case, it is preferable to use sprockets with the same configuration (same size and same shape) for the first sprocket 61 and the second sprocket 62, for example.

[0023] The chain 63 engages with teeth on the outer periphery of the first sprocket 61 and the second sprocket 62. The chain 63 is formed in a ring shape, with the first sprocket 61 and the second sprocket 62 disposed on the inside.

[0024] The chain adjustment mechanism 64 is disposed on the path of the chain 63. The chain adjustment mechanism 64 is configured to be capable of adjusting the tension of the chain 63 (capable of adjusting the relative phase between the first sprocket 61 and the second sprocket 62). In other words, the chain adjustment mechanism 64 has a function of being capable of adjusting the parallelism between the third imaginary center line C3 of the support arm 30 and the second imaginary center line C2 of the second arm 20. As the chain adjustment mechanism 64, for example, a turnbuckle, a chain tensioner, or the like can be used.

[0025] (Configuration of the first position adjustment unit) The first position adjustment unit 70 is capable of adjusting the distance between the support point 13 on the first virtual center line C1 and the first weight 15. The first position adjustment unit 70 of this embodiment is capable of adjusting the length of the first arm 10 between the support point 13 and the first end 11. The first position adjustment unit 70 adjusts the position of the first weight 15 manually, semi-automatically, or automatically according to the mass of the supported object 50. In the case of manual adjustment, specifically, the mass of the supported object 50 is measured by any method, and according to the size, the user of the weight compensation device 1 releases the fixing of the first position adjustment unit 70, changes the length, and fixes it again. The fixing method of the first position adjustment unit 70 may be, but is not limited to, a lock pin, a screw, a catch clip, or the like. In the case of semi-automatic adjustment, specifically, the mass of the supported object 50 is measured by any method, the user of the weight compensation device 1 manually inputs the mass of the supported object 50 as a numerical value into the weight compensation device 1, and the first position adjustment unit 70 automatically adjusts the distance between the support point 13 of the first arm 10 and the first weight 15 using an actuator according to the numerical value of the inputted mass of the supported object 50 (the mass of the supported object 50 acquired by the user). Examples of the actuator by which the first position adjustment unit 70 adjusts the distance between the support point 13 and the first weight 15 include a ball screw, a wire chain, a hydraulic cylinder, a linear motor, and a link mechanism. The first position adjustment unit 70 of this embodiment adjusts the length of the first arm 10 by expanding and contracting between the support point 13 and the first end 11 of the first arm 10. The first position adjustment unit 70 is disposed on the first arm 10 between the support point 13 and the first end 11. In the case of automatic adjustment, the weight compensation device 1 directly detects the mass of the supported object 50, and the user does not have to input the numerical value of the mass of the supported object 50, which is performed in the case of semi-automatic adjustment. Instead, the first position adjustment unit 70 automatically adjusts the distance between the support point 13 and the first weight 15 using the value of the mass of the supported object 50 obtained by direct measurement (the detected mass of the supported object 50) in the same manner as in the semi-automatic adjustment. However, in any of the manual, semi-automatic, and automatic adjustment methods, the purpose is to adjust the distance between the support point 13 and the first weight 15, so a configuration in which only the first weight 15 moves on the first arm 10 without changing the distance between the support point 13 and the first end 11 may also be used.

[0026] (Configuration of the second position adjustment unit) The second position adjustment unit 80 is capable of adjusting the distance between the support point 13 on the second virtual center line C2 and the second weight 25. The second position adjustment unit 80 of this embodiment is capable of adjusting the length of the second arm 20 between the support point 13 and the tip 21. The second position adjustment unit 80 adjusts the position of the second weight 25 manually, semi-automatically, or automatically according to the mass of the supported object 50. In the case of manual adjustment, specifically, the mass of the supported object 50 is measured by any method, and according to the size, the user of the weight compensation device 1 releases the fixing of the second position adjustment unit 80, changes the length, and fixes it again. The fixing method of the second position adjustment unit 80 may be, but is not limited to, a lock pin, a screw, a catch clip, or the like. In the case of semi-automatic adjustment, specifically, the mass of the supported object 50 is measured by any method, the user of the weight compensation device 1 manually inputs the mass of the supported object 50 as a numerical value into the weight compensation device 1, and the second position adjustment unit 80 automatically adjusts the distance between the support point 13 of the second arm 20 and the second weight 25 using an actuator according to the numerical value of the inputted mass of the supported object 50 (the mass of the supported object 50 acquired by the user). Examples of the actuator by which the second position adjustment unit 80 adjusts the distance between the support point 13 and the second weight 25 include a ball screw, a wire chain, a hydraulic cylinder, a linear motor, and a link mechanism. The second position adjustment unit 80 of this embodiment adjusts the length of the second arm 20 by expanding and contracting between the base end 22 and the tip 21 of the second arm 20. The second position adjustment unit 80 is disposed on the second arm 20 between the support point 13 and the tip 21. In the case of automatic adjustment, the weight compensation device 1 directly detects the mass of the supported object 50, and the user does not have to input the numerical value of the mass of the supported object 50, which is performed in the case of semi-automatic adjustment. Using the value of the mass of the supported object 50 obtained by direct measurement (the detected mass of the supported object 50), the second position adjustment unit 80 automatically adjusts the distance between the support point 13 and the second weight 25 using the same method as in the semi-automatic case. However, in any of the manual, semi-automatic, and automatic adjustment methods, the purpose is to adjust the distance between the support point 13 and the second weight 25, so a configuration in which only the second weight 25 moves on the second arm 20 without changing the distance between the support point 13 and the tip 21 may also be used.The second position adjustment unit 80 basically moves simultaneously with the first position adjustment unit 70 in accordance with the mass of the supported body 50. As a result, the first position adjustment unit 70 and the second position adjustment unit 80 simultaneously adjust the positions of the first weight 15 and the second weight 25. However, the adjustment of the positions of the first weight 15 and the second weight 25 is not limited to being performed simultaneously.

[0027] Here, in the weight compensation device 1 of this embodiment, each member is preferably configured so as to satisfy the following two formulas. L1 M = La Ma (Eq. 1) L2 M = Lb Mb (Eq. 2)

[0028] L1 is the distance between the support point 13 and the second end 12 of the first arm 10. L2 is the distance between the first support end 31 and the second support end 32 of the support arm 30. M is the mass of the (first) supported object 50 . La is the distance from the support point 13 to the center of gravity of the first weight 15 when the first arm 10 is fully extended. Lb is the distance from the support point 13 to the center of gravity of the second weight 25 when the second arm 20 is fully extended. Ma is the mass of the first weight 15 . Mb is the mass of the second weight 25.

[0029] Furthermore, after the mass of the supported body 50 to be lifted becomes lighter and the positions of the first weight 15 and the second weight 25 are adjusted by the first position adjustment unit 70 and the second position adjustment unit 80, it is preferable that each component of the weight compensation device 1 of this embodiment is configured so as to further satisfy the following two formulas. La' = M' / M La (Equation 3) Lb' = M' / M Lb (Equation 4)

[0030] La′ is the distance between the center of gravity of the first weight 15 after the movement (the position of the first end portion 11 in this embodiment) and the support point 13. Lb' is the distance between the center of gravity position of second weight 25 after movement (the position of tip 21 in this embodiment) and support point 13. Therefore, Lb' is the length of second arm 20 after adjustment. M' is the mass of the (second) supported object 50 which is smaller than the mass M of the (first) supported object.

[0031] Next, a case where the weight compensation device 1 according to this embodiment lifts the supported object 50 upward in the vertical direction Dv will be described. In the weight compensation device 1, the supported object 50 is attached to the second support end 32 of the support arm 30. At this time, the supported object 50 can be moved to an arbitrary position by rotating the first arm 10 around the first axis O1 at the support point 13 and rotating the support arm 30 around the second axis O2 at the support first end 31. At this time, the second arm 20 is maintained in a state always parallel to the support arm 30 by the interlocking mechanism 60. As a result, the composite center of gravity of the supported object 50, the first weight 15, and the second weight 25 always coincides with the support point 13, and the weight of the supported object 50 is compensated regardless of the position of the supported object 50, and the supported object 50 can be stably supported. When the mass of supported object 50 changes, as shown in Equations 3 and 4, the distance from support point 13 to the center of gravity of first weight 15 and the distance from support point 13 to the center of gravity of second weight 25 are changed to make the composite center of gravity of supported object 50, first weight 15, and second weight 25 coincide with support point 13. This compensates for the weight of supported object 50 regardless of the mass of supported object 50, making it possible to stably support supported object 50.

[0032] (Action and effect) In the weight compensation device 1 of the first embodiment described above, the position of the first weight 15 and the position of the second weight 25 relative to the support point 13 can be adjusted by the first position adjustment unit 70 and the second position adjustment unit 80. Therefore, even if the supported object 50 to be lifted changes and the mass of the supported object 50 changes, it is possible to adjust the weight compensation force for compensating for the weight of the supported object 50 simply by adjusting the positions of the first weight 15 and the second weight 25. Therefore, it is possible to adjust the weight compensation force for supported objects 50 of different masses without preparing multiple counterweights other than the first weight 15 and the second weight 25 as spares for adjustment.

[0033] Moreover, the positions of the first weight 15 and the second weight 25 are simultaneously adjusted by the first position adjustment unit 70 and the second position adjustment unit 80 in accordance with the mass of the supported object 50. As a result, stable adjustment of the weight compensation force in accordance with the mass of the supported object 50 is possible.

[0034] Furthermore, the first weight 15 is disposed on a first imaginary center line C1 relative to the support point 13. The second weight 25 is disposed on a second imaginary center line C2 relative to the support point 13. Therefore, even if the first arm 10 or the second arm 20 is rotated about the support point 13 in order to move the supported object 50, the first weight 15 and the second weight 25 each move in an orbit of a constant radius so as to form a spherical surface centered on the support point 13. Therefore, covers can be easily installed on the first weight 15 and the second weight 25 to protect surrounding workers and objects.

[0035] Second Embodiment Next, a second embodiment of the weight compensation device according to the present disclosure will be described. In the weight compensation device described below, components common to the first embodiment will be denoted by the same reference numerals in the drawings, and descriptions thereof will be omitted.

[0036] 2, in the weight compensation device of the second embodiment, the structure around the support arm is different from that of the first embodiment.

[0037] (Configuration of support arm adjustment part) The support arm adjustment unit 90 is capable of adjusting the distance of the supported body 50 from the second end 12 that exists on the third imaginary center line C3. The support arm adjustment unit 90 is capable of adjusting the position of the second support end 32 to which the supported body 50 is attached, on the third imaginary center line C3, with respect to the first support end 31 that is disposed at a position overlapping with the second end 12. The support arm adjustment unit 90 is capable of adjusting the distance between the second end 12 and the supported body 50 on the third imaginary center line C3 and the position of the second support end 32 to which the supported body 50 is attached, on the third imaginary center line C3. two Virtual center line C 2 The support arm adjustment unit 90 adjusts the length of the support arm 30A in conjunction with the second position adjustment unit 80 so that the ratio of the distance between the support point 13 and the second weight 25 on the third imaginary center line C2 to the distance between the second support end 32 and the first support end 31 on the third imaginary center line C3 is constant. The support arm adjustment unit 90 of this embodiment is capable of adjusting the length of the support arm 30A so as to change the distance between the first support end 31 and the second support end 32 on the third imaginary center line C3. The support arm adjustment unit 90 adjusts the length of the support arm 30A in a linear manner in conjunction with the second position adjustment unit 80 so that the ratio of the distance between the support point 13 and the second weight 25 on the second imaginary center line C2 to the distance between the second support end 32 and the first support end 31 on the third imaginary center line C3 is always maintained constant between the initial state (before adjustment) and after adjustment. Specifically, so that the ratio of the length of support arm 30A to the length of second arm 20 before adjustment and the ratio of the length of support arm 30A to the length of second arm 20 after adjustment are always the same, the distance from base end 22, which is in the same position as support point 13, to tip end 21 and the distance from first support end 31 to second support end 32 are extended and retracted in tandem to adjust the length of second arm 20 and the length of support arm 30A simultaneously.

[0038] More specifically, the support arm adjustment unit 90 is an actuator that automatically adjusts the length of the support arm 30A in conjunction with the movement of the second position adjustment unit 80. Examples of the actuator include a structure that can linearly change the distance between the first support end 31 and the supported object 50 on the third imaginary center line C3, such as a ball screw, a wire, a chain, a hydraulic cylinder, or a linear motor. The support arm adjustment unit 90 is disposed on the support arm 30A between the first support end 31 and the second support end 32. The support arm adjustment unit 90 extends and contracts in conjunction with the second position adjustment unit 80.

[0039] Here, in the weight compensation device 1A of the second embodiment after the position of the supported object 50 is adjusted by the support arm adjustment unit 90, each member is preferably configured so as to satisfy the following formula. Lb'=M / Mb L2' (Equation 5)

[0040] L2' is the distance between the center of gravity position of the supported object 50 after movement (the position of the second support end 32 in this embodiment) and the first support end 31. Therefore, L2' is the length of the support arm 30A after adjustment. The second position adjustment unit 80 and the support arm adjustment unit 90 may each be driven and controlled to satisfy Equation 5 by an actuator using an external power source, but a mechanism for linking them using a wire or a double-acting hydraulic cylinder without using an external power source may also be used. When a wire is used, a transmission is applied in the transmission path to realize Equation 5, and when a double-acting hydraulic cylinder is used, Equation 5 is realized by appropriately setting the ratio of the cylinder bore.

[0041] (Action and effect) In the weight compensation device 1A of the second embodiment, the second position adjustment unit 80 and the support arm adjustment unit 90 work together so that the ratio between the length of the second arm 20 and the length of the support arm 30A after the distance between the support point 13 and the second weight 25 on the second virtual center line C2 and the distance between the second end 12 and the center of gravity of the supported object 50 on the third virtual center line C3 are adjusted by the second position adjustment unit 80 and the support arm adjustment unit 90 remains constant from the initial state. Since the ratio between the length of the second arm 20 and the length of the support arm 30A remains constant from the initial state, even if the distance between the first support end 31 and the supported object 50 on the third virtual center line C3 is changed, the composite center of gravity of the supported object 50, the first weight 15, and the second weight 25 always coincides with the support point 13, and the weight compensation force for compensating for the weight of the supported object 50 can be maintained regardless of the position of the supported object 50. Therefore, even in a linearly narrow space such as a narrow section, it is possible to easily lift supported object 50, which is a heavy object, while adjusting the position of supported object 50 by linearly extending and contracting motion of support arm 30A. In this way, it is possible to accommodate spatial constraints in which weight compensation device 1A is used.

[0042] In other words, by adjusting the length of the support arm 30A using the support arm adjustment unit 90, the distance between the first support end 31 and the supported object 50 on the third imaginary center line C3 is changed linearly, and a structure for linearly adjusting the position of the supported object 50 can be easily formed while minimizing space.

[0043] <Third embodiment> Next, a third embodiment of the weight compensation device according to the present disclosure will be described. In the weight compensation device described below, components common to the first and second embodiments will be denoted by the same reference numerals in the drawings and descriptions thereof will be omitted.

[0044] 3, in the weight compensation device of the third embodiment, the structure around the support arm is different from that of the first and second embodiments.

[0045] The first support arm 36 is connected to the second end 12 of the first arm 10 at a first support end 31B which is one end. The first support arm 36 is connected to the second support arm 37 at a first rotating end 361 which is the other end. The first support arm 36 extends in a straight line from the first support end 31B to the first rotating end 361. The first support arm 36 is disposed such that the first support end 31B overlaps with the second end 12, and is connected to the first arm 10 so as to be rotatable about a second axis O2 with respect to the first support end 31B as the center.

[0046] The second support arm 37 has a second rotating end 371, which is one end, rotatably connected to the first rotating end 361. The second rotating end 371 of the second support arm 37 is connected to rotate coaxially with the first rotating end 361 of the first support arm 36. The second support arm 37 is capable of supporting the supported object 50 at the other end, which is the second support end 32B.

[0047] The support arm adjustment unit 90B of the third embodiment is capable of adjusting the angle of the second support arm 37 relative to the first support arm 36. The support arm adjustment unit 90B of the third embodiment is capable of rotating the second support arm 37 relative to the first support arm 36 so as to change the distance between the first support end 31B and the second support end 32B on the third imaginary center line C3. That is, the support arm adjustment unit 90B rotatably connects the second rotation end 371 to the first rotation end 361. The second position adjustment unit 80 and the support arm adjustment unit 90B work together to expand and contract the distance between the support point 13 and the center of gravity of the second weight 25 on the second imaginary center line C2 and the distance between the second support end 32B and the first support end 31B on the third imaginary center line C3, and rotate the second rotation end 371 relative to the first rotation end 361 so that the ratio of the distance between the support point 13 and the center of gravity of the second weight 25 on the second imaginary center line C2 to the distance between the support second end 32B and the support first end 31B on the third imaginary center line C3 is constant. That is, the support arm adjustment unit 90B rotates the second support arm 37 relative to the first support arm 36 so that the second support end 32B to which the supported object 50 is attached is always positioned on the third imaginary center line C3. At that time, the first support arm 36 is not always positioned on the third imaginary center line C3, but rotates about the second axis O2 relative to the first arm 10 together with the rotation of the second support arm 37. The second position adjustment unit 80 and the support arm adjustment unit 90B move the first support arm 36 and the second support arm 37 in cooperation with each other so that the ratio between the distance between the support point 13 and the second weight 25 on the second imaginary center line C2 and the distance between the first support end 31B and the second support end 32B on the third imaginary center line C3 is maintained constant between the initial state (before adjustment) and after adjustment. Specifically, the second position adjustment unit 80 and the support arm adjustment unit 90B work in conjunction to expand or contract the distance between the support point 13 and the center of gravity of the second weight 25 and rotate the second support arm 37 relative to the first support arm 36 so that the ratio of the distance between the first support end 31B and the second support end 32B on the third imaginary center line C3 to the length of the second arm 20 before adjustment is the same as the ratio of the distance between the first support end 31B and the second support end 32B on the third imaginary center line C3 to the length of the second arm 20 after adjustment.

[0048] (Action and effect) In the weight compensation device 1B of the third embodiment, the second position adjustment unit 80 and the support arm adjustment unit 90B are linked so that the ratio between the length of the second arm 20 after the distance between the support point 13 and the second weight 25 on the second virtual center line C2 and the distance between the second end 12 and the center of gravity of the supported object 50 on the third virtual center line C3 is adjusted by the second position adjustment unit 80 and the support arm adjustment unit 90B and the distance between the first support end 31B and the second support end 32B on the third virtual center line C3 is constant. Since the ratio between the length of the second arm 20 and the distance between the first support end 31B and the second support end 32B on the third virtual center line C3 is constant from the initial state, even if the distance between the first support end 31B and the supported object 50 on the third virtual center line C3 is changed, the composite center of gravity of the supported object 50, the first weight 15, and the second weight 25 always coincides with the support point 13, and the weight compensation force for compensating for the weight of the supported object 50 can be maintained regardless of the position of the supported object 50. Therefore, in the second embodiment, the function achieved by the linear extension and contraction of the support arm 30A is achieved in the third embodiment by the support arm 30B, which is composed of the first support arm 36, the second support arm 37, and a support arm adjustment part 90B that performs the joint bending function, and the function of varying the distance between the first support end 31B and the second support end 32B on the third imaginary center line C3 is achieved by the multi-joint structure.

[0049] In addition, the second support arm 37 is rotated relative to the first support arm 36 by the support arm adjustment unit 90B. This linearly changes the distance between the first support end portion 31B and the supported object 50 on the third imaginary center line C3 while avoiding placement of movable parts on the third imaginary center line C3. Therefore, it is possible to easily form a structure that linearly adjusts the position of the supported object 50 while suppressing interference of parts on the third imaginary center line C3.

[0050] <Fourth embodiment> Next, a fourth embodiment of the weight compensation device according to the present disclosure will be described. In the weight compensation device described below, components common to the first to third embodiments will be denoted by the same reference numerals in the drawings and will not be described.

[0051] 4, in the weight compensation device of the fourth embodiment, the structure around the first arm is different from that of the first to third embodiments. The weight compensation device 1C of the fourth embodiment further includes a first arm adjustment unit 40 on the first arm 10C.

[0052] (Configuration of the first arm adjustment unit) The first arm adjustment unit 40 is capable of adjusting the position of the second end 12 relative to the support point 13. The first arm adjustment unit 40 is capable of adjusting the position of the second end 12 on the first virtual center line C1 relative to the support point 13. The first arm adjustment unit 40 adjusts the ratio of the distance between the support point 13 and the first weight 15 to the distance between the support point 13 and the second end 12 to be constant. The first arm adjustment unit 40 of this embodiment is capable of adjusting the length of the first arm 10C so as to change the distance between the second end 12 and the support point 13 on the first virtual center line C1. The first arm adjustment unit 40 linearly adjusts the length of the first arm 10C so that the ratio of the distance between the support point 13 and the second end 12 on the first virtual center line C1 to the distance between the support point 13 and the first end 11 on the first virtual center line C1 is maintained constant between the initial state (before adjustment) and after adjustment. Specifically, the first arm adjustment unit 40 adjusts the length of the first arm 10C by extending or retracting the second end 12 relative to the support point 13 so that the ratio of the distance between the support point 13 and the first end 11 to the distance between the support point 13 and the second end 12 before adjustment by the first position adjustment unit 70 is the same as the ratio of the distance between the support point 13 and the second end 12 to the distance between the support point 13 and the first end 11 after adjustment by the first position adjustment unit 70.

[0053] More specifically, the first arm adjustment unit 40 is an actuator that automatically adjusts the length of the first arm 10C in conjunction with the movement of the first position adjustment unit 70. Examples of the actuator include a structure that can linearly change the distance between the support point 13 and the second end 12 on the first virtual center line C1, such as a ball screw, a wire chain, a hydraulic cylinder, and a linear motor. The first arm adjustment unit 40 is disposed on the first arm 10C between the support point 13 and the second end 12. The first arm adjustment unit 40 basically moves simultaneously with the first position adjustment unit 70. However, the adjustment of the distance between the support point 13 and the second end 12 and the adjustment of the distance between the support point 13 and the center of gravity of the first weight 15 are not limited to being performed simultaneously.

[0054] Here, in the weight compensation device 1C of the fourth embodiment after the position of the second end 12 is adjusted by the first arm adjustment unit 40, each member is preferably configured so as to satisfy the following formula. La' = M / Ma L1' (Eq. 6)

[0055] L1' is the distance between the support point 13 and the second end 12 after the movement.

[0056] (Action and effect) In the weight compensation device 1C of the fourth embodiment, the first position adjustment unit 70 and the first arm adjustment unit 40 are interlocked so that the ratio of the distance between the support point 13 and the first weight 15 and the distance between the support point 13 and the second end 12 remains constant from the initial state after the distance between the support point 13 and the first weight 15 on the first virtual center line C1 and the distance between the support point 13 and the second end 12 on the first virtual center line C1 are adjusted by the first position adjustment unit 70 and the first arm adjustment unit 40. Since the ratio of the distance between the support point 13 and the first weight 15 and the distance between the support point 13 and the second end 12 remains constant from the initial state, even if the distance between the support point 13 and the second end 12 on the first virtual center line C1 is changed, the composite center of gravity of the supported object 50, the first weight 15, and the second weight 25 always coincides with the supporting point 13, and the weight compensation force for compensating for the weight of the supported object 50 can be maintained regardless of the position of the supported object 50. Therefore, the height of the weight compensation device 1C as a whole can be adjusted, and even in a narrow space where the height is limited, it is possible to lift supported object 50, which is a heavy object, while adjusting the position of supported object 50. In this way, it is possible to accommodate spatial restrictions in which weight compensation device 1C is used.

[0057] In other words, by adjusting the length of the first arm 10C using the first arm adjustment unit 40, the distance between the support point 13 and the second end 12 on the first imaginary center line C1 is changed linearly, and a structure can be easily formed in a space-saving manner in which the positions of the second end 12 to which the support arm 30 is connected and the supported object 50 are linearly adjusted.

[0058] (Other embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included.

[0059] In addition, the interlocking mechanism 60 is not limited to the structure of this embodiment as long as it can interlock the support arms 30, 30A, and 30B and the second arm 20 so that they are parallel to each other. For example, the interlocking mechanism 60 may be a structure using a pulley or a wire, a structure using a push rod, a structure using a hydraulic system, or a structure using a drive shaft. In addition, in order to improve the operability and stability of each arm, a configuration using a spring, a damper, a brake, or the like may be used. In this case, the buffer mechanism such as a spring, a damper, or a brake may be arranged at the support point 13 to stabilize the operation of the first arms 10 and 10C and the second arm 20, or may be arranged at the support point 13 to stabilize the operation of the first arms 10 and 10C and the support arms 30, 30A, and 30B at the second end 12.

[0060] Furthermore, the first position adjustment unit 70 is not limited to a structure capable of adjusting the length of the first arm 10, 10C, such as a structure that expands and contracts between the support point 13 and the first end 11 of the first arm 10, 10C. In other words, the first position adjustment unit 70 may have a structure capable of adjusting the position of the support point 13 and the first weight 15. For example, the first position adjustment unit 70 may be a rail-like member arranged on the first arm 10, 10C to allow the first weight 15 to move. Furthermore, the first position adjustment unit 70 may have a structure in which overlapping cylindrical members expand and contract. Furthermore, the first position adjustment unit 70 may have a structure in which the first arm 10, 10C is provided with a rail-like member arranged on the first arm 10, 10C to allow the first weight 15 to move. joint may be arranged in a link structure.

[0061] Furthermore, the first position adjustment unit 70 is not limited to a structure in which the position of the first weight 15 with respect to the supporting point 13 is automatically adjusted. In other words, the first position adjustment unit 70 may be a structure in which the position of the first weight 15 with respect to the supporting point 13 can be manually adjusted.

[0062] The second position adjustment unit 80 is not limited to a structure capable of adjusting the length of the second arm 20, such as a structure that expands and contracts between the base end 22 and the tip 21 of the second arm 20. In other words, the second position adjustment unit 80 may have a structure capable of adjusting the positions of the support point 13 and the second weight 25. For example, the second position adjustment unit 80 may be a rail-like member arranged on the second arm 20 to allow the second weight 25 to move. The second position adjustment unit 80 may also have a structure in which a cylindrical member expands and contracts. The second position adjustment unit 80 may have a structure in which the second weight 25 is movable between the support point 13 and the tip 21. joint may be arranged in a link structure.

[0063] Furthermore, the second position adjustment unit 80 is not limited to a structure in which the position of the second weight 25 with respect to the support point 13 is automatically adjusted. In other words, the second position adjustment unit 80 may be a structure in which the position of the second weight 25 with respect to the support point 13 can be manually adjusted.

[0064] Furthermore, the support arm adjustment unit 90 is not limited to a structure in which the position of the supported object 50 relative to the second end 12 is automatically adjusted. In other words, the support arm adjustment unit 90 may be a structure in which the position of the supported object 50 relative to the second end 12 can be manually adjusted.

[0065] Furthermore, the first arm adjustment unit 40 is not limited to a structure capable of adjusting the length of the first arm 10C, such as a structure that expands and contracts between the support point 13 and the second end 12 of the first arm 10C. In other words, the first arm adjustment unit 40 may have a structure capable of adjusting the positions of the support point 13 and the second weight 25. For example, the first arm adjustment unit 40 may have a structure using a wire and a pulley, a rack and pinion structure, or a structure using a hydraulic cylinder.

[0066] Furthermore, the first arm adjustment unit 40 is not limited to a structure in which the position of the second end 12 relative to the support point 13 is automatically adjusted. In other words, the first arm adjustment unit 40 may be a structure in which the position of the second end 12 relative to the support point 13 can be manually adjusted.

[0067] <Additional Notes> The weight compensation device described in the embodiment can be understood, for example, as follows.

[0068] (1) The weight compensation device according to the first aspect includes a first arm 10 having a first end 11 and a second end 12, and a support point 13 between the first end 11 and the second end 12 that is rotatably supported, and a support 13 extending from the support point 13 to the first end 11. cormorant a first weight 15 supported by the first arm 10 at a position spaced apart in the extending direction of the first arm 10 as shown in FIG. 1; a second arm 20 supported at the supporting point 13 so as to be rotatable independently of the first arm 10 and extending from the supporting point 13 in a direction intersecting the extending direction of the first arm 10; a second weight 25 supported by the second arm 20 at a position spaced apart from the supporting point 13 in the extending direction of the second arm 20; a support arm 30 rotatably connected to the first arm 10 at the second end 12, extending in a direction parallel to and opposite to the extending direction of the second arm 20 and capable of supporting a supported body 50; and the support arm 30 and the second arm 20 are interlocked in operation so as to be always parallel to each other. The device is equipped with an interlocking mechanism 60, a first position adjustment unit 70 capable of adjusting the distance between the support point 13 and the first weight 15 on a virtual line connecting the second end 12, the support point 13, and the first end 11, and a second position adjustment unit 80 capable of adjusting the distance between the support point 13 and the second weight 25 on a virtual line extending from the support point 13 in the extension direction of the second arm 20, wherein the second arm 20 is rotatable independently with respect to the first arm 10 around a first axis O1 passing through the support point 13, and the support arm 30 is rotatable with respect to the first arm 10 around a second axis O2 passing through the second end 12 on the first arm 10 and extending parallel to the first axis O1.

[0069] In this weight compensation device, the position of the first weight 15 and the position of the second weight 25 relative to the support point 13 can be adjusted by the first position adjustment unit 70 and the second position adjustment unit 80. Therefore, even if the supported object 50 to be lifted changes and the mass of the supported object 50 changes, the weight compensation force for compensating for the weight of the supported object 50 can be adjusted simply by adjusting the positions of the first weight 15 and the second weight 25. Therefore, the weight compensation force can be adjusted according to the mass of different supported objects 50 without having to prepare multiple extra counterweights as spares for adjustment other than the first weight 15 and the second weight 25.

[0070] (2) A weight compensation device of a second aspect is a weight compensation device of (1), wherein the first position adjustment unit 70 and the second position adjustment unit 80 may simultaneously adjust the position of the first weight 15 and the position of the second weight 25 in accordance with the mass of the supported body 50.

[0071] Thereby, the positions of the first weight 15 and the second weight 25 are simultaneously adjusted by the first position adjustment unit 70 and the second position adjustment unit 80 in accordance with the mass of the supported object 50. As a result, stable adjustment of the weight compensation force in accordance with the mass of the supported object 50 becomes possible.

[0072] (3) A weight compensation device of the third aspect is a weight compensation device of (1) or (2), and may further include a support arm adjustment unit 90 capable of adjusting the position of the supported object 50 relative to the second end 12 so that the ratio of the distance between the second end 12 and the supported object 50 on a virtual line connecting the second end 12 and the supported object 50 and the distance between the support point 13 and the second weight 25 on a virtual line connecting the support point 13 and the second weight 25 is constant.

[0073] As a result, the ratio of the distance between the second end 12 and the supported object 50 and the distance between the support point 13 and the second weight 25 remains constant from the initial state, so that even if the position of the supported object 50 relative to the second end 12 is changed, the composite center of gravity of the supported object 50, the first weight 15, and the second weight 25 always coincides with the support point 13, and the weight compensation force for compensating for the weight of the supported object 50 can be maintained regardless of the position of the supported object 50. Therefore, even in a linearly narrow space such as a narrow section, it is possible to lift the supported object 50, which is a heavy object, while adjusting the position of the supported object 50 by a linear extension and contraction action. In this way, it is possible to respond to the spatial constraints in which the weight compensation device is used.

[0074] (4) A weight compensation device according to a fourth aspect is a weight compensation device of (3), wherein the support arm adjustment unit 90 may be capable of bending the support arm 30 to adjust the distance between the second end 12 and the supported object 50.

[0075] This allows the position of supported body 50 to be changed linearly with respect to second end portion 12. Therefore, a structure for linearly adjusting the position of supported body 50 can be realized with a simple structure that uses a joint structure.

[0076] (5) A weight compensation device according to a fifth aspect is the weight compensation device of (3), wherein the support arm 30 has a first support arm 36 having one end connected to the first arm 10 at the second end 12, and a second support arm 37 having one end rotatably connected to the other end of the first support arm 36 and capable of supporting the supported body 50 at the other end, and the support arm adjustment unit 90 may be capable of adjusting the angle of the second support arm 37 relative to the first support arm 36.

[0077] This avoids placing movable parts on the imaginary line connecting the second end 12 and the supported object 50, and changes the position of the supported object 50 linearly relative to the second end 12. Therefore, it is possible to easily form a structure that suppresses interference between parts on the imaginary line connecting the second end 12 and the supported object 50, and adjusts the position of the supported object 50 linearly.

[0078] (6) A weight compensation device of the sixth aspect may be any one of the weight compensation devices of (1) to (5), and may further include a first arm adjustment unit 40 capable of adjusting the position of the second end 12 relative to the support point 13 so that the ratio between the distance between the support point 13 and the first weight 15 on a virtual line connecting the support point 13 and the first weight 15 and the distance between the support point 13 and the second end 12 on a virtual line connecting the support point 13 and the second end 12 is constant.

[0079] As a result, the ratio of the distance between the support point 13 and the first end 11 and the distance between the support point 13 and the second end 12 remains constant from the initial state, so that even if the position of the second end 12 relative to the support point 13 is changed, the composite center of gravity of the supported object 50, the first weight 15, and the second weight 25 always coincides with the support point 13, and the weight compensation force for compensating for the weight of the supported object 50 can be maintained regardless of the position of the supported object 50. As a result, the height of the weight compensation device as a whole can be adjusted, and even in a narrow space such as a narrow section, it is possible to lift the supported object 50, which is a heavy object, while adjusting the position of the supported object 50. In this way, it is possible to accommodate the spatial constraints in which the weight compensation device is used.

[0080] (7) A weight compensation device according to a seventh aspect is the weight compensation device of (6), wherein the first arm adjustment unit 40 is capable of adjusting the length of the first arm 10.

[0081] This changes the distance between supporting point 13 and second end 12 on a virtual line that linearly connects first end 11 and second end 12. Therefore, a structure that linearly adjusts the positions of second end 12 to which supporting arm 30 is connected and supported object 50 can be easily formed while minimizing space.

[0082] (8) A weight compensation device according to an eighth aspect is any one of the weight compensation devices (1) to (7), and the first position adjustment unit 70 and the second position adjustment unit 80 may detect the mass of the supported object 50 supported by the support arms 30, 30A, 30B, and automatically adjust the position of the first weight 15 and the position of the second weight 25 according to the detected mass of the supported object 50.

[0083] (9) A weight compensation device according to a ninth aspect is any one of the weight compensation devices (1) to (7), and the first position adjustment unit 70 and the second position adjustment unit 80 may automatically adjust the position of the first weight 15 and the position of the second weight 25 in accordance with the mass of the supported body 50 obtained by the user. [Explanation of symbols]

[0084] 1, 1A, 1B, 1C Self-weight compensation device 10, 10C First arm 11 First end 12 Second end 13 Support points O1 First axis C1 First virtual center line 15 First Weight 20 Second Arm 21 Tip 22 Proximal end C2 Second virtual center line 25 Second Weight 30, 30A, 30B Support arms 31, 31B Support first end 32, 32B Support second end O2 2nd axis C3 Third virtual center line 50 Supported object 60 Interlocking mechanism 61 First sprocket 62 Second sprocket 63 Chain 64 Chain adjustment mechanism 70 First position adjustment section 80 Second position adjustment section 90, 90B Support arm adjustment part 36 First support arm 361 First rotating end 37 Second support arm 371 Second rotating end 40 First arm adjustment part Dv Vertical direction

Claims

1. a first arm having a first end and a second end, the first arm being rotatably supported at a support point between the first end and the second end; a first weight supported by the first arm at a position spaced apart in an extension direction of the first arm from the support point toward the first end; a second arm supported at the support point so as to be rotatable independently of the first arm and extending from the support point in a direction intersecting an extension direction of the first arm; a second weight supported by the second arm at a position spaced from the support point in an extension direction of the second arm; a support arm rotatably connected to the first arm at the second end and extending in a direction parallel to and opposite to the direction in which the second arm extends, the support arm being capable of supporting a supported object; an interlocking mechanism that interlocks the operations of the support arm and the second arm so that they are always parallel to each other; a first position adjustment unit capable of adjusting a position of the first weight relative to the support point so as to change a distance between the support point and the first weight on a virtual line connecting the second end, the support point, and the first end; a second position adjustment unit capable of adjusting a position of the second weight relative to the support point so as to change a distance between the support point and the second weight on a virtual straight line extending from the support point in an extension direction of the second arm, the second arm is rotatable independently of the first arm about a first axis passing through the support point, A weight compensation device wherein the support arm is rotatable relative to the first arm about a second axis that passes through the second end on the first arm and extends parallel to the first axis.

2. The weight compensation device according to claim 1 , wherein the first position adjustment unit and the second position adjustment unit simultaneously adjust the position of the first weight and the position of the second weight in accordance with a mass of the supported object.

3. The weight compensation device described in claim 1 or 2, further comprising a support arm adjustment unit capable of adjusting the position of the supported object relative to the second end so that the ratio of the distance between the second end and the supported object on a virtual line connecting the second end and the supported object to the distance between the support point and the second weight on a virtual line connecting the support point and the second weight is constant.

4. The weight compensation device according to claim 3 , wherein the support arm adjustment portion is capable of adjusting a distance between the second end portion and the supported object by bending the support arm.

5. The support arm includes: a first support arm having one end connected to the first arm at the second end; a second support arm having one end rotatably connected to the other end of the first support arm and capable of supporting the supported object at the other end, The weight compensation device according to claim 3 , wherein the support arm adjustment portion is capable of adjusting an angle of the second support arm relative to the first support arm.

6. The weight compensation device according to any one of claims 1 to 5, further comprising a first arm adjustment unit capable of adjusting the position of the second end relative to the support point so that a ratio between a distance between the support point and the first weight on a virtual line connecting the support point and the first weight and a distance between the support point and the second end on a virtual line connecting the support point and the second end is constant.

7. The weight compensation device according to claim 6 , wherein the first arm adjustment portion is capable of adjusting a length of the first arm.

8. The weight compensation device described in any one of claims 1 to 7, wherein the first position adjustment unit and the second position adjustment unit detect the mass of the supported object supported by the support arm, and automatically adjust the position of the first weight and the position of the second weight according to the detected mass of the supported object.

9. The weight compensation device according to any one of claims 1 to 7, wherein the first position adjustment unit and the second position adjustment unit automatically adjust the position of the first weight and the position of the second weight according to the mass of the supported object obtained by a user.

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