JPH05200690A - Compression spring type balancer for robot - Google Patents

Abstract

PURPOSE:To make a center shaft easy to mode up and down concentrically with a vertical cylinder, and less in wear of this center shaft, consequently make it so as to be excellent in maintainability. CONSTITUTION:An I member 09 installed on a top plate 010 of a vertical cylinder 08 is pivoted to an upper end of a rocker member of a robot and a end I member 016 installed in the lower end of a center shaft 013 inserted into a center hole of a bottom plate 01 2 of the vertical cylinder 08 is pivoted to an upper end of the support member of the robot. In addition, the center shaft 013 is made so as to be energized upward by dint of a compression spring 017 elastically installed concentrically in space between the upper end of the center shaft 013 and the bottom plate 012 of the vertical cylinder 08. In addition, this balancer is provided with a bushing 1, where the center shaft 013 erected on the bottom plate 012 of the vertical cylinder 08 is inserted through and also the compression spring 017 is externally inserted, and a self-aligning bearing 4 inserted in an interval between the upper end of the center shaft 013 and a spring upper end seat plate 7 inserted into an upper part of the center shaft 013.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression spring type balancer for robots.

[0002]

2. Description of the Related Art Conventionally, as an articulated robot, for example, as shown in the perspective view of FIG. 2, the robot is pivotally mounted on a base 01 and reciprocally about a vertical axis ZZ, that is, in the direction of arrow z. A rotating horizontal turntable 02 and a horizontal axis X-
A support member 03 that pivotally supports X, a lower end portion pivotally mounted on a horizontal axis XX, and a swinging member 04 that reciprocally rotates around the horizontal axis X-X, that is, in the direction of arrow x, and a right end portion on this upper end portion. An operating arm 06 pivotally attached to a provided horizontal axis Y-Y, which reciprocally rotates around this, that is, in the direction of arrow y, and a grip base 05 is connected to the left end, and a lower end to a support member 03.
Of the compression spring type balancer 07 which is pivotally attached to the upper end of the rocking member 04 and is pivotally attached to the upper part of the swinging member 04. In this type of robot, the balancer 07 is provided to balance the weight of the swinging member 04 when reciprocally rotating around the horizontal axis XX and reduce the torque fluctuation of the swinging member 04. .. As shown in the vertical sectional view of FIG. 3, this is a top plate 010 fixed to the upper end of a vertical cylinder 08 and having an upper end eye member 09 projecting therefrom, and a shaft insertion hole 011 fixed to the lower end of the vertical cylinder 08. Bottom plate 012
A spring upper end seat 014, which is screwed onto the upper end of the central shaft 013 inserted therein and has a diameter slightly smaller than the inner diameter of the vertical cylinder 08, and a diameter slightly smaller than the inner diameter of the vertical cylinder 08, which is attached to this upper surface with screws. A shock-absorbing ring 015 made of tetrafluoroethylene resin having a diameter slightly larger than that of the spring upper end seat 014, and a lower end eye member 016 screwed to the lower end of the central shaft 013 via a screw portion.
And the upper end is housed in the vertical cylinder 08 and the upper end of the spring is seated 0
The coil type compression spring 017 is in pressure contact with the lower surface of 14 and has its lower end in pressure contact with the upper surface of the bottom plate 012. In this type of balancer 07, the spring upper end seat 014 axially moves inside the vertical cylinder 08 via the central axis 013, so that the compression spring 017 expands and contracts to balance the weight of the joint. At that time, since the spring upper end seat 014 contacts the top plate 010 and the vertical cylinder 08 via the buffer ring 015, no impact noise is generated and abrasion can be prevented. Moreover, since the spring upper end seat 014 is always held coaxially with the vertical cylinder 08, when the compression spring 017 is compressed,
This does not curve in a bow and its side does not come into contact with the side wall of the vertical cylinder 08.

However, in such a structure, the central shaft 013 and the shaft insertion hole 011 of the bottom plate 012, the buffer ring 015 and the vertical cylinder 08 are arranged so that the central shaft 013 moves up and down coaxially with the vertical cylinder 08. Since the inner surface and the inner surface are slid with respect to each other, when the soft buffer ring 015 is worn or deformed, the central axis 013 is inclined and the wear may increase.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances, and the center axis is easily moved up and down coaxially with the vertical cylinder, and the center axis is less worn. An object of the present invention is to provide a compression spring type balancer for a robot having excellent maintainability.

[0005]

To this end, the present invention provides
The upper end eye member protruding from the top plate of the vertical cylinder is pivotally attached to the upper end of the swing member of the robot, and the lower end eye member protruding from the lower end of the central axis inserted into the center hole of the bottom plate of the vertical cylinder is The central axis of the robot is pivotally attached to the upper end of the supporting member, and the central shaft is moved upward by a compression spring coaxially mounted in the vertical cylinder between the upper end of the central shaft and the bottom plate of the vertical cylinder. In a compression spring type balancer for a robot that is biased to, a bearing tube on which the central shaft is inserted and which is erected on the bottom plate of the vertical cylinder and the compression spring is externally inserted,
It is characterized by comprising a self-aligning bearing inserted between an upper end portion of the central shaft and a spring upper end seat inserted in an upper portion of the central shaft.

[0006]

According to this structure, the following actions are performed. (1) Since a bearing cylinder is provided upright on the bottom plate of the vertical cylinder and through which the central shaft is inserted and the compression spring is externally inserted, it is possible to prevent the central shaft from coming off from the axis of the vertical cylinder as much as possible. Reduce the wear of the central shaft. (2) Since the self-aligning bearing is inserted between the upper end portion of the central shaft and the spring upper end seat plate inserted in the upper portion of the central shaft, the resultant compression force of the compression spring is the axial line of the central shaft. When a bending moment is applied to the upper end seat plate, the upper end seat plate is slightly tilted to eliminate the bending moment, and no radial load is generated on the upper end bearing and the lower end bearing of the bearing cylinder. Reduces wear on the central shaft. (3) With the structure of (2) above, the axial torsional moment when the compression spring receives an axial load can be eliminated, and the load on the central axis is reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The same reference numerals as those in FIGS. 2 to 3 denote the same members as those in the drawings, and in the longitudinal sectional view of FIG. It is coaxially and integrally erected on the bottom plate 012 and has a central axis of 0.
13 is inserted, and the lower part of the compression spring 017 is a bearing tube to be externally inserted, and the upper end bearing 2 and the lower end bearing 3 are fitted to the upper end and the lower end, respectively. Reference numeral 4 denotes a self-aligning bearing fixed to the upper end of the central shaft 013 via a grooved nut 5 and a split pin 6, and a spherical roller bearing is used in this embodiment. 7 is a compression spring 01 whose lower end is supported on the bottom plate 012.
7 is a spring upper end plate for mounting the upper end of 7 on the self-aligning bearing 4 with an initial compression force.

In such a structure, as shown in the figure, the swinging frame 04 (FIG. 2) of the robot swings,
As the rotational moment increases, the length between the upper eye member 09 and the lower eye member 016 of the balancer increases, so that the compression spring 017 is compressed and its spring force increases to increase the increased rotational moment. It works in the direction of reducing.

According to the structure of this embodiment, the following effects can be obtained. (1) Since a bearing cylinder is provided upright on the bottom plate of the vertical cylinder and through which the central shaft is inserted and the compression spring is externally inserted, it is possible to prevent the central shaft from coming off from the axis of the vertical cylinder as much as possible. It is possible to reduce the wear of the central shaft and thus improve the maintainability of the balancer. (2) Since the self-aligning bearing is inserted between the upper end of the central shaft and the spring upper end seating plate inserted in the upper part of the central shaft, the resultant compression force of the compression spring is the axial line of the central shaft. When a bending moment is applied to the upper end seat plate, the upper end seat plate is slightly tilted to eliminate the bending moment, and no radial load is generated on the upper end bearing and the lower end bearing of the bearing cylinder. The wear of the central shaft can be reduced and thus the maintainability of the balancer can be improved. (3) Also, with the structure of (2) above, it is possible to eliminate the axial torsion moment when the compression spring receives an axial load, reduce the load on the central axis, and therefore,
It is possible to improve the maintainability of the balancer.

[0010]

In summary, according to the present invention, the upper end eye member projectingly provided on the top plate of the vertical cylinder is pivotally attached to the upper end of the rocking member of the robot and is inserted through the center hole of the bottom plate of the vertical cylinder. A lower end eye member protruding from the lower end of the shaft is pivotally attached to the upper end of the supporting member of the robot, and coaxially between the upper end of the central shaft and the bottom plate of the vertical cylinder in the vertical cylinder. In a compression spring type balancer for a robot in which the central axis is biased upward by an elastic compression spring, the central axis is inserted while the central axis is inserted while the compression spring is installed outside on the bottom plate of the vertical cylinder. By including a bearing tube to be inserted, and a self-aligning bearing inserted between the upper end of the central shaft and the spring upper end seat inserted in the upper part of the central shaft,
The present invention is extremely useful industrially because the central axis of the robot is easy to move up and down coaxially with the vertical cylinder, and the central axis is less worn. Therefore, the compression spring type balancer for robot having excellent maintainability is obtained. ..

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a known articulated robot.

FIG. 3 is a vertical sectional view showing the compression spring type balancer of FIG.

[Explanation of symbols]

 1 bearing cylinder 2 upper end bearing 3 lower end bearing 4 self-aligning bearing 5 grooved nut 6 split pin 7 spring upper end seat plate 08 vertical cylinder 09 upper end eye member 010 top plate 012 bottom plate 013 center shaft 016 lower end eye member 017 compression spring

Claims (1)

[Claims] 1. An upper end eye member projecting from a top plate of a vertical cylinder is pivotally attached to an upper end of a rocking member of a robot, and is projected from a lower end of a central shaft inserted into a central hole of a bottom plate of the vertical cylinder. A lower eye member is pivotally attached to the upper end of the support member of the robot, and a compression spring coaxially mounted in the vertical cylinder between the upper end of the central axis and the bottom plate of the vertical cylinder. In a compression spring type balancer for a robot configured to urge the central axis upward, a bearing tube which is erected on the bottom plate of the vertical cylinder and through which the central axis is inserted and the compression spring is externally inserted, A compression spring type balancer for a robot, comprising: a self-aligning bearing inserted between an upper end of the central shaft and a spring upper end seat inserted in the upper part of the central shaft.