JPH10225891A - Balancer mechanism for industrial robot, and installation and adjusting method for its balancer mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balancer mechanism for an industrial robot which can be easily installed on a robot main body without receiving spring force of a coil spring. SOLUTION: A balancer mechanism for an industrial robot comprises a hollow spring case 4 having an installation member 9 supported on an upper end surface 4b to be rotatable with an upper part of an arm 5, a stopper inserting through hole 8' in part of a cylindrical surface, and a lower end surface 4a detachable to the cylindrical surface, a rod 3 having a step 8b protruded in an outer circumferential direction at one end, a connection member 2 supported at the other end to be rotatable with a support point on a rotation base 1, and composed to be inserted to the lower end surface 4a of the spring case 4, a compression plate 7 having a through hole for the rod 3 to be inserted at a center part of a disc, and composed to be movable between the rod step part 3b and the lower end surface 4a of the spring case 4, and a coil spring 6 disposed between the compression plate 7 and the lower end surface 4a of the spring case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balancer mechanism for an articulated industrial robot, and more particularly to a balancer mechanism that can be easily mounted and adjusted on a robot body, a method for mounting the balancer mechanism on a robot body, and a method for mounting the same. Related to the adjustment method after mounting.

[0002]

2. Description of the Related Art As shown in FIG.
A multi-joint type industrial robot in which the arm 13 can be tilted back and forth (left and right in the position shown in the drawing) with respect to 1 is provided with a spring mechanism in order to balance gravity when the arm 13 is tilted. In some cases, a built-in balancer mechanism (spring case 12) is attached to both side surfaces of the arm 13. By compensating for the gravitational torque by the balancer mechanism, the capacity of the actuator is reduced, and as a result, the size, weight, and cost of the actuator are reduced.

[0003] The configuration of a conventional balancer mechanism is disclosed in, for example, Japanese Utility Model Publication No. 7-18547, but is rotatably supported on an upper portion of an arm 13 as shown in FIG. It has a spring case 12, a knuckle 14 rotatably supported on the swivel base 11, and a step (or plate) 15b which is fastened at one end to the knuckle 14 by a screw and protrudes in the outer peripheral direction at the other end. The rod 15 and the coil spring 16 arranged in the spring case 12 such that the biasing range is regulated by the step 15b of the rod.

In order to protect the bearings of the balancer mechanism and the support of the revolving base 11 and the balancer mechanism and the support of the arm 13, the upper end surface 12 b of the spring case and the rod are not affected by any tilting posture of the arm 13. The rod 15 needs to be supported on the turning base 11 so that a gap is formed between the step 15b. For example, in FIG. 7 of JP-A-6-170780, by adjusting the amount of screwing of the rod 15 and the knuckle 14 as shown in FIG. The distance up to 15b, that is, the rod length was adjusted.

A method of attaching the above-mentioned conventional balancer mechanism to the robot body will be described with reference to FIG. First, the bottom face 1
In a state where the spring case main body 12 excluding 2a, the lower end surface 12a of the spring case, the rod 15, and the coil spring 16 are detached from the robot main body, the step portion 15b of the rod 15 is moved to the upper end surface 12b of the spring case. Side, and inserted into the spring case 12 so that the coil spring 16 has one end abutting on the step 15b of the rod.
2, and in a state where the lower end surface 12 a of the spring case is in contact with the other end of the coil spring 16, a force is applied to the lower end surface 12 a in a direction to compress the coil spring 16, and the lower end surface 12 a When they come into contact with the coil spring main body 12, they are connected to each other. Thereafter, the upper end surface 12 b of the spring case is rotatably supported on the upper part of the arm 13. When compressing the coil spring 16, a compression device (not shown) suitable for this operation is used.

Next, the knuckle 14 is screwed into the end of the rod 15 to some extent, and the knuckle 14 is
Support on top. At this point, the state shown in FIG. 5B is reached. In this state, the upper end surface 12b of the spring case is in contact with the step 15b of the rod. Finally, rod 15
5B is rotated as indicated by the arrow in FIG. 5B to adjust the amount of screwing of the rod 15 into the knuckle 14, and as shown in FIG. There is a gap between the rod 12b and the step 15b of the rod. Further, when the spring length is determined by the posture of the arm 13, it is necessary to adjust the screwing amount of the rod 15 into the knuckle 14 again to set the spring length, that is, the rod length.

[0007]

As described above, in the prior art balancer mechanism, the amount of screwing of the rod 15 into the knuckle 14 is required when the balancer mechanism is mounted on the robot body or when the rod length is set after mounting. Had to be adjusted. Adjustment of this screwing amount is rod 1
5 has to be rotated or a nut (not shown) interposed between the connecting portion of the rod 15 and the knuckle 14 has to be rotated. Performing the operation on the rod 15 is a heavy burden on the worker. By the way, regarding the connection between the rod 15 and the knuckle 14, a structure in which the rod 15 is slidably attached to the knuckle 14 is conceivable, but it is easy to slide the rod with the spring force by human power. However, after all, the rod 15 itself or the nut is rotated by using a wrench or a hand tool having a function similar thereto to adjust the rod length by applying the screwing structure as in the above-mentioned prior art. There was only.

The present invention has been made to solve the above-mentioned problems of the prior art, and has a balancer mechanism of an industrial robot which can be easily attached to a robot body without receiving the spring force of a coil spring. It is another object of the present invention to provide a method of attaching the balancer mechanism to the robot body and a method of adjusting the balancer mechanism after attaching the balancer mechanism to the robot body.

[0009]

According to the present invention, in order to achieve the above object, a stroke range in which a spring force is not applied to a rod is provided, and the rod can be slid freely within this stroke range. Adjustment of the rod length after attachment to the robot body and attachment of the balancer mechanism to the robot body is performed within the stroke range of the rod.

That is, according to the first aspect of the present invention, one end is rotatably supported by a fulcrum on the revolving base, and the other end is rotatably supported on an upper part of the arm which is tiltably supported on the revolving base. A balancer mechanism for an industrial robot having a coil spring adapted to have a mounting tool adapted to be rotatably supported on an upper end of an arm and a through hole for inserting a stopper in a part of a cylindrical surface. And a hollow spring case having a lower end surface detachably attached to the cylindrical surface, a stepped portion protruding in the outer peripheral direction at one end, and a fulcrum on the revolving base at the other end. A rod having a connector adapted to be movably supported and inserted through the lower end surface of the spring case, and a through hole for inserting the rod into a disk-shaped central portion; Having a compression plate movable between the rod step and the lower end surface of the spring case, and a coil spring disposed between the compression plate and the lower end surface of the spring case. The feature is a balancer mechanism for an industrial robot.

In order to explain the operation relating to the configuration of the first aspect, the configuration of the third aspect which defines the method of mounting the balancer mechanism to the robot body according to the first aspect is described below. That is, in the invention according to claim 3,
2. A method for mounting a balancer mechanism having the configuration according to claim 1 on an industrial robot main body, wherein each of a spring case main body excluding a lower end surface, a lower end surface of the spring case, a rod, a compression plate, and a coil spring is an industrial robot main body. Insert the stopper into the through hole for inserting the stopper, insert the rod into the spring case so that the step is on the upper end side of the spring case, and insert the compression plate through the rod. Then, insert the coil spring into the spring case so that one end of the coil spring comes into contact with the compression plate, and contact the lower end surface of the spring case with the other end of the coil spring. In this state, a force is applied to the lower end face in the direction to compress the coil spring, and the lower end face When they come into contact with the main body of the spring, they are joined together, and then the upper end of the spring case is rotatably supported on the upper part of the arm, whereby the operating range is regulated by the upper end of the spring case and the stopper. Characterized in that a rod operable without receiving a coil spring force between the compression plate and the compression plate is rotatably supported on a fulcrum on a revolving base. And

A difference between the balancer mechanism according to the first aspect and the conventional one is that a compression plate movable between the rod step and the lower end surface of the spring case is provided. The point is that a coil spring is arranged between the lower end surface of the spring case and a through hole for inserting a stopper in a part of the cylindrical surface of the spring case. The stopper inserted into the stopper insertion through-hole regulates the operation range of the compression plate, but does not restrict the operation of the rod, so that when the balancer mechanism is attached to the robot body, According to the mounting method of the third aspect, the operation range of both the compression plate and the coil spring abutting on the compression plate is restricted by the stopper inserted into the through hole for inserting the stopper. The rod which can operate without receiving a coil spring force between the compression plate and the compression plate whose operation range is restricted by the stopper can be easily supported on a fulcrum on the turning base. To remove the stopper after the balancer mechanism has been attached to the robot body, see FIG.
As shown in (1), the arm 5 is tilted until the compression plate 7 pushed by the step of the rod 3 moves to the turning base side from the position of the stopper insertion through hole 8 '. When it is no longer receiving the coil spring force, it may be removed.

[0013] In the balancer mechanism according to the first aspect and the method of mounting the balancer mechanism according to the third aspect, as described in the second aspect, the rod with respect to the fulcrum on the turning base is attached to the balancer mechanism. A rod length adjusting means for adjusting the length of the rod is provided, and when the balancer mechanism is attached to the robot body, the rod is rotatably supported by a fulcrum on the turning base as described in claim 4. After that, the length of the rod based on the fulcrum on the turning base is adjusted by the rod length adjusting means. As the rod length adjusting means, a screwing mechanism as in the related art is also conceivable. However, by adopting the structure described in claim 1, a compression plate whose operating range is regulated by the upper end surface of the spring case and the stopper is provided. Since the rod can be operated without receiving the coil spring force, it is not necessary to limit to the screwing mechanism provided to cope with the coil spring force. Only by using a mechanism that slidably attaches to a connecting tool such as a knuckle that is connected to the rod, the operator can easily hold the part of the rod by hand and slide it to set the rod length to a predetermined length. Can be adjusted to length.

According to a second aspect of the present invention, a method of adjusting the rod length of the balancer mechanism having the rod length adjusting means according to the second aspect of the present invention after the robot body is attached (in a state where the stopper is already removed) is as described in the fifth aspect. The arm is tilted until the compression plate is positioned on the lower end side of the spring case with respect to the stopper insertion through hole, and the stopper is inserted into the stopper insertion through hole. With respect to a rod which can operate without receiving a coil spring force between the compression plate and the restricted compression plate, the length of the rod with respect to a fulcrum on the turning base, that is, the rod length is adjusted. Thus, if it becomes necessary to change the restoring force of the balancer mechanism during use of the robot, the rod length can be easily changed by the above-described adjustment method.

The configuration and operation of each claim of the present invention have been described above. Here, the configuration of each claim will be supplementarily described. Regarding the position of the stopper insertion through hole provided on the cylindrical surface of the spring case in the longitudinal direction of the spring case, it is better to install it near the lower end surface of the spring case so that the coil spring force of the rod is not affected. However, as shown in FIG. 4, as shown in FIG.
At least, the position of the stopper insertion through hole should be closer to the upper end surface of the spring case than the position of the compression plate when the arm is most inclined, that is, when the coil spring is most compressed. The shape of the stopper is not limited as long as the compression plate receiving the coil spring force can be stably pressed. The stopper satisfies the condition that the operation range of the compression plate is restricted but the operation of the rod is not restricted. It must be structured.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is an overall view of an industrial robot having a vertical articulated structure to which the balancer mechanism of the present invention is applied.
(B) The figure is a left side view. A lower arm 5 having a link mechanism that can be tilted back and forth with respect to the turning base 1 is connected to a turning base 1 that can turn with respect to the base. An upper arm 10 capable of tilting up and down with respect to the arm 5 is connected. On both sides of the lower arm 5, in order to balance gravity when the lower arm 5 tilts,
A balancer mechanism (spring case 4) incorporating a spring mechanism is attached. In addition, the detailed description of the wrist mechanism, the drive shaft motor, and the like provided at the tip of the upper arm 10 is omitted because they are not directly related to the gist of the present invention.

FIGS. 1A and 1B are vertical sectional views showing the internal structure of the balancer mechanism. FIG. 1A shows a state where the stopper 8 is inserted, and FIG. 1B shows a state where the stopper 8 is not inserted. ing. The spring case 4 having a hollow structure has a mounting member 9 rotatably supported on the upper part of the arm 5 on an upper end surface 4b and a through hole 8 'for inserting a stopper in a part of the cylindrical surface. The lower end surface 4a is detachable from the cylindrical surface. The rod 3 inserted into the lower end surface 4a of the spring case 4 has a stepped portion 3b protruding in the outer peripheral direction at one end thereof, and rotatably supports the fulcrum on the revolving base at the other end. It has a connecting tool 2 which is set in a predetermined manner. The compression plate 7 has a through hole for inserting the rod 3 in the center of the disk, and is movable between the rod step 3b and the lower end surface 4a of the spring case. The coil spring 6 is disposed between the compression plate 7 and the lower end surface 4a of the spring case.

The lower end surface 4a of the spring case and the cylindrical surface may be screwed or bolted as long as the structure is detachable. Further, the stopper 8 inserted into the stopper insertion through hole 8 'can stably hold down the compression plate 7 to which the coil spring force is applied, and regulates the operation of the compression plate 7. As long as the operation 3 is not restricted, its structure may be arbitrary. Naturally, it is assumed that the shape of the stopper insertion through hole 8 'matches the structure of the stopper. Regarding the position of the stopper insertion through hole 8 'in the longitudinal direction of the spring case, it is preferable to install the stopper hole near the lower end side of the spring case since the operating range in which the coil spring force of the rod is not received is widened. . Specifically, the adjustment range of the length up to the step portion 3b, that is, the rod length, based on the fulcrum on the turning base is expanded, and the arm 5 is tilted as shown in FIG. The balancer mechanism can be attached even in this state. However, as shown in FIG. 4, the position of the through hole for inserting the stopper is smaller than the position of the compression plate in the state where the arm is most tilted, that is, the state where the coil spring is most compressed, so that there is no bearing when the stopper is inserted and removed. It is necessary to install so that it is on the upper end side of the case.

The method of attaching the balancer mechanism to the industrial robot body will be described. The spring case body 4 excluding the lower end face 4a, the lower end face 4a of the spring case,
With each of the rod 3, the compression plate 7, and the coil spring 6 removed from the industrial robot main body,. Insert the stopper 8 into the stopper insertion through hole 8 '. . The rod 3 is inserted into the spring case 4 so that the step 3b is on the upper end surface 4b side of the spring case 4. . The compression plate 7 is inserted into the rod 3 and disposed in the spring case 4 so as to be in contact with the stopper 8. . The coil spring 6 is inserted into the spring case 4 such that one end of the coil spring 6 contacts the compression plate 7. . With the lower end surface 4a of the spring case in contact with the other end of the coil spring 6, a force is applied to the lower end surface 4a in a direction to compress the coil spring 6, and the lower end surface 4a
When they come into contact with the main body of the spring case 4, the two are connected. Although it depends on what is used, a force of several tens of kilograms is required to compress the coil spring 6, so a dedicated compressor (not shown) is used for compressing the coil spring 6.

[0020] An attachment 9 on the upper end surface of the spring case is rotatably supported on the upper part of the arm 5. . The rod 3 operable without receiving a coil spring force between the upper end surface 4b of the spring case and the compression plate 7 whose operation range is regulated by the stopper 8.
Is rotatably supported on a fulcrum on the turning base. FIG.
As shown in (a), the rod 3 applies a coil spring force between the upper end surface 4b of the spring case and the compression plate 7 while the end on the turning base side is not connected to a fulcrum on the turning base. The rod can be operated without receiving it, and the weight of the rod itself is about several kg. Therefore, the operator slides the rod 3 within the above range while grasping the portion of the rod 3 close to the turning base side by hand. And can easily be supported on a fulcrum on the swivel base. . When the stopper is removed after the balancer mechanism has been attached to the robot body, as shown in FIG. 4, the compression plate 7 pushed by the step of the rod 3 is closer to the turning base than the position of the stopper insertion through hole 8 '. The arm 5 is tilted until the stopper 8 moves to the position shown in FIG. As described above, as shown in FIG. 1B, the spring force is generated in the entire stroke of the balancer mechanism.

In the above-mentioned balancer mechanism and its mounting method, the balancer mechanism is provided with a rod length adjusting means for adjusting the length of the rod based on the fulcrum on the turning base, that is, the rod length adjusting means. When the mechanism is attached to the robot main body, the rod 3 may be rotatably supported on a fulcrum on the turning base, and then the rod length may be adjusted by the rod length adjusting means. As the rod length adjusting means, the end of the rod 3 is slidably attached to a connecting tool 2 such as a knuckle connected to a fulcrum on the turning base, and the rod 3 is connected by fastening with a fixing tool such as a bolt. A simple mechanism such as fixing to 2 is sufficient.

In actual use of the robot, it may be necessary to change the restoring force of the balancer mechanism. In this case, a method of replacing the coil spring 6 with one having a different coil spring force or a method of replacing the rod 3 with one having a different length can be considered. In both methods, the balancer mechanism is disassembled once and the coil spring or the coil spring is replaced. After replacing the rod with a predetermined one, it is necessary to restore the rod again, and this operation requires a considerable number of steps. Therefore, as described above, when it is necessary to provide the balancer mechanism with the rod length adjusting means and change the restoring force of the balancer mechanism, the compression plate 7 is inserted with the stopper while the balancer mechanism is attached to the robot body. The arm 5 is tilted until it is positioned closer to the lower end surface 4a of the spring case than the through hole 8 'for the stopper, and the stopper 8 is inserted into the through hole 8' for inserting the stopper. The rod length is adjusted for the rod 3 that can operate without receiving a coil spring force between the compression plate 7 and the compression plate 7 whose operation range is restricted.

Finally, a method of removing the balancer mechanism from the robot body will be described. The compression plate 7 is located at the lower end face 4 of the spring case more than the stopper insertion through hole 8 ′.
The arm 5 is tilted until it is located on the side a, and the stopper 8 is inserted into the through hole 8 'for inserting the stopper.
1A, the coil spring force is not applied to the rod 3 as shown in FIG. 1 (a). In this state, the balancer mechanism is removed from the robot body in the reverse procedure of the mounting. What should I do?

[0024]

According to the balancer mechanism of the industrial robot according to the first aspect and the method of mounting the balancer mechanism according to the third aspect, the compression made movable between the rod step and the lower end surface of the spring case is achieved. A plate is provided, a coil spring is disposed between the compression plate and the lower end surface of the spring case, and a through hole for inserting a stopper is provided in a part of the cylindrical surface of the spring case. The operating range of both the compression plate and the coil spring that comes into contact with the compression plate is restricted by the stopper inserted into the compression plate. Therefore, the rod can operate without receiving the coil spring force between the upper end surface of the spring case and the compression plate whose operating range is regulated by the stopper, and the connection between the rod and the turning base is screwed as in the prior art. Is no longer necessary, and the balancer mechanism can be easily supported on a fulcrum on the turning base.

According to the balancer mechanism of the industrial robot according to the second aspect and the method of mounting the balancer mechanism according to the fourth aspect, the balancer mechanism according to the first and third aspects, wherein the balancer mechanism is based on a fulcrum on a turning base. A rod length adjusting means for adjusting the length of the rod, that is, the rod length, is provided,
When the balancer mechanism is mounted on the robot body, the rod is rotatably supported on a fulcrum on the turning base, and then the rod length is adjusted by the rod length adjusting means.
Therefore, the operator only holds the rod part by hand, with a mechanism that slidably attaches the end of the rod to a connecting tool such as a knuckle connected to a fulcrum on the turning base.
By sliding this, the rod length can be easily adjusted to a predetermined length.

According to a fifth aspect of the present invention, in the balancer mechanism having the rod length adjusting means according to the second aspect, the compression plate is located closer to the lower end surface of the spring case than the stopper insertion through hole. Tilt the arm until it is positioned and insert the stopper into the through hole for inserting the stopper, so that it can operate without receiving the coil spring force between the upper end surface of the spring case and the compression plate whose operating range is regulated by the stopper The rod length was adjusted for the rod that became. Therefore, even if it is necessary to change the restoring force of the balancer mechanism during use of the robot, it is possible to respond only by changing the rod length without replacing the rod or the coil spring.

As described above, according to the balancer mechanism of the industrial robot according to the present invention, and the method of mounting and adjusting the balancer mechanism, the man-hour for mounting the balancer mechanism on the robot body is reduced, and the burden on the worker when mounting is reduced. This has led to a reduction in work efficiency, and the work efficiency during robot assembly has been improved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing an internal structure of a balancer mechanism according to an embodiment of the present invention, and FIG.
(B) shows a state in which the stopper 8 is not inserted.

FIGS. 2A and 2B are overall views of an industrial robot having a vertical articulated structure to which a balancer mechanism according to an embodiment of the present invention is applied, wherein FIG. 2A is a front view, and FIG. FIG.

FIG. 3 is a vertical sectional view showing a state where an arm 5 of the balancer mechanism according to the embodiment of the present invention is tilted.

FIG. 4 illustrates a balancer mechanism according to an embodiment of the present invention.
FIG. 9 is a diagram showing a state in which a stopper 8 is attached to and detached from a stopper insertion through hole 8 ′.

FIG. 5 is a vertical cross-sectional view showing the internal structure of a balancer mechanism in the prior art; FIG. 5A is an overall view of an industrial robot having a vertical articulated structure; FIG. (C) shows the state immediately after the screwing adjustment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Swivel base 2 Connecting tool (knuckle) 3 Rod 3b Step part of rod 4 Spring case 4a Lower end surface of spring case 4b Upper end surface of spring case 5 Arm 6 Coil spring 7 Compression plate 8 Stopper 8 'Through hole for stopper insertion 9 Mounting Ingredient

Claims (5)

[Claims] 1. A coil spring having one end rotatably supported on a fulcrum on a turning base and the other end rotatably supported on an upper portion of an arm supported on the turning base so as to be tiltable. An industrial robot having a balancer mechanism, comprising: an upper end face having a fixture rotatably supported on an upper part of the arm; a cylindrical part having a through hole for inserting a stopper; and a lower end face. Has a hollow spring case detachably attached to the cylindrical surface, and has a stepped portion protruding in the outer peripheral direction at one end and rotatably supports the fulcrum on the turning base at the other end. A rod adapted to be inserted through the lower end surface of the spring case, and a through-hole for inserting the rod into a disk-shaped central portion; A compression plate movable between a step portion and a lower end surface of the spring case; and a coil spring disposed between the compression plate and a lower end surface of the spring case. Balancer mechanism for industrial robots. 2. A balancer mechanism for an industrial robot according to claim 1, further comprising a rod length adjusting means for adjusting a length of the rod with reference to a fulcrum on the turning base. . 3. An upper end surface is rotatably supported on an upper portion of an arm tiltably supported on a revolving base, and has a through hole for inserting a stopper in a part of a cylindrical surface, and a lower end surface is a cylindrical surface. And a hollow spring case detachably attached to the main body, a stepped portion protruding in the outer peripheral direction at one end, and the other end rotatably supported by a fulcrum on the turning base. A rod having a connector, and being inserted through the lower end surface of the spring case, and a through hole for inserting the rod in a disk-shaped central portion, wherein the rod stepped portion and the spring An industrial robot having a balancer mechanism including a compression plate movable between a lower end surface of a case and a coil spring disposed between the compression plate and a lower end surface of the spring case. In the method of attaching to the body, in the state where each of the spring case main body excluding the lower end surface, the lower end surface of the spring case, the rod, the compression plate, and the coil spring is detached from the industrial robot main body, Insert a stopper into the through hole, insert the rod into the spring case such that the stepped portion is on the upper end surface side of the spring case, and insert the compression plate through the rod so as to contact the stopper. The coil spring was disposed in the spring case, and the coil spring was inserted into the spring case such that one end thereof was in contact with the compression plate, and a lower end surface of the spring case was contacted with another end of the coil spring. In this state, a force is applied to the lower end face in the direction to compress the coil spring, When the spring case is brought into contact with the spring case body, the two are joined. Thereafter, the upper end surface of the spring case is rotatably supported on the upper part of the arm. Wherein the rod operable without receiving a coil spring force is rotatably supported on a fulcrum on the revolving base. 4. The method according to claim 1, wherein the rod is rotatably supported on a fulcrum on the turning base, and then the length of the rod with respect to the fulcrum on the turning base is adjusted. A method for mounting a balancer mechanism for an industrial robot according to claim 3. 5. An upper end surface is rotatably supported on an upper portion of an arm supported on a revolving base so as to be tiltable, and has a through hole for inserting a stopper in a part of a cylindrical surface, and a lower end surface is a cylindrical surface. And a hollow spring case detachably attached to the main body, a stepped portion protruding in the outer peripheral direction at one end, and the other end rotatably supported by a fulcrum on the turning base. A rod having a connector, and being inserted through the lower end surface of the spring case, and a through hole for inserting the rod in a disk-shaped central portion, wherein the rod stepped portion and the spring A compression plate movable between the lower end surface of the case, a coil spring disposed between the compression plate and the lower end surface of the spring case, and a fulcrum on the revolving base. A method for adjusting a balancer mechanism of an industrial robot, comprising: a rod length adjusting means for adjusting a length of a rod; wherein the balancer mechanism is attached to an industrial robot main body; The arm is tilted until it is positioned on the lower end surface side of the spring case with respect to the stopper insertion through hole, and a stopper is inserted into the stopper insertion through hole, whereby the upper end surface of the spring case and the compression plate Wherein the length of the rod, which is operable without receiving a coil spring force between the rod and the fulcrum on the turning base, is adjusted. How to adjust the mechanism.