Industrial robot

Abstract

An industrial robot 10 comprises an arm 2 which includes a proximal portion rotatably supported on a horizontal rotation shaft of a frame 1 in a cantilever state, a cylindrical case portion formed from the proximal portion side to a distal end of the arm to have an opening portion on the proximal portion side, and an arm distal end portion. The industrial robot also comprises a balancer device which includes a rod 3b , and a cylinder 3a in which the rod 3b is reciprocated. An engagement portion at a distal end of the rod, and a rear end 5 of the cylinder are rotatably supported between a pair of first support portions c of the frame, and between a pair of second support portions b inside the cylindrical case portion, respectively, so that the cylindrical case portion and the balancer device do not interfere with each other in an extent of rotation of the arm.

Description

technical field [0001] The present invention relates to an industrial robot having a balancing device for reducing the load on a motor and a reducer acting on a drive arm. Background technique [0002] In order to maintain the mass of the arm and the mass of the end effector attached to the tip of the robot using only the power of the motor, a large-capacity motor and a reducer are required. In particular, the moment load due to gravity increases as the shaft goes toward the root, so there is a problem that a large-capacity motor and a reducer are required. [0003] Therefore, in Patent Document 1, it is disclosed that a spring-type balancer is attached to the side of the arm, and one end is supported above the arm rotation shaft and the other end is supported on the arm side. In addition, Patent Document 2's Figure 4 , Figure 5 discloses a spring-type balancing device installed behind the arm. In addition, Patent Document 3 discloses a balance device formed of a hydrauli...

AI Technical Summary

Problems solved by technology

[0004] However, in the devices of Patent Documents 1 and 2, in order to obtain a large generating force, there is a problem that the spring-loaded housing becomes thicker and longer, and there is a problem that if the balance device is installed on the side of the arm, the width of the robot will be reduced. If the size becomes larger, if the balance device is installed behind the arm, the rotation interference radius at the rear of the robot will become larger

In addition, there is a problem that not only a plurality of springs are used, but also many parts are used, so not only the weight of the balancer is increased, but also it takes time to assemble, and the cost increases

[0015] However, the device of Patent Document 6 has a problem in that the balance device is arranged between the pair of arm bodies, so that it interferes with the arm rotation axis and can only rotate forward.

Therefore, it is only necessary to set the cantilever as in Patent Document 1, but at this time, the strength of the arm is lowered.

In addition, there is a problem that since the tip of the rod is arranged below the frame, it also interferes with the frame

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