JPS6321980Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a mounting device for a resistance type welding gun in an industrial robot.

Conventionally, devices of this kind are known in which a welding gun is mounted on a robot arm or other movable member via a mounting bracket, with a welding gun supported by a shaft at the root. In order to avoid this, it is conceivable that the welding gun is activated before the movable member has sufficiently stopped at a predetermined welding point, and in this case, the welding gun is subjected to an impact force on its root shaft support. This tends to cause uneven wear, which in turn tends to cause misalignment of the welding points or misalignment of the electrode mating surfaces, which is undesirable.

The purpose of the present invention is to obtain a device free of such inconveniences, and a welding gun 3 is pivotally supported on a robot arm or other movable member 1 via a mounting bracket 2 by a shaft 4 at its root. In this type, an elastic member 6 such as hard rubber is interposed between the outer periphery of the shaft 4 and the corresponding bearing hole 5 on the bracket 2 side.

In the illustrated example, the movable member 1 consists of a robot arm, the distal end of which is provided with the mounting bracket 2 via a welding transformer 1a, and the welding gun 3 has an upper fixed gun arm 3a and a lower movable gun arm. The gun arm 3b is pivotally supported at the tip of the bracket 2 at the root shaft 4 described above. In the drawing, 3c is an operating cylinder 3d for opening and closing the movable gun arm 3b, and 3d is a secondary conductor connecting each gun arm 3a, 3b to the transformer 1a.

As clearly shown in FIG. 2, the shaft 4 is inserted at both ends thereof into a pair of left and right bearing holes 5, 5 formed on the side of the bracket 2, and is supported by each bearing hole 5. The above-mentioned elastic member 6 made of hard rubber or the like is interposed between the inside and the outer periphery of the shaft 4. Each elastic member 6 is provided with metal collars 6a, 6a on its inner and outer peripheries.

To explain its operation, consider, for example, the case where the welding gun 3 is activated before the movable member 1 has sufficiently stopped at a predetermined welding point. Although some buffering is applied, the buffering is absorbed by the elastic member 6 on the outer periphery of the shaft 4, thereby preventing uneven wear that tends to occur on the shaft support.

In this way, according to the present invention, a hard rubber or other elastic member 6 is interposed between the shaft 4 and the bearing hole 5 on the outer periphery of the shaft support at the root of the welding gun 3. The impact acting on the shaft support is absorbed by the elastic member 6, thereby eliminating uneven wear that tends to occur on the shaft support, eliminating misalignment of welding points due to uneven wear, and facilitating subsequent work. In addition, it has advantages such as being reliable, having a simple structure, and being inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a side view of an example of the present device, and FIG. 2 is a cross-sectional view taken along the line -2. 1...Moving member, 2...Mounting bracket, 3...
...Welding gun, 4...Shaft, 5...Bearing hole, 6...Elastic member.

Claims (1)

[Scope of utility model registration request] In a type in which a welding gun 3 is rotatably supported by a shaft 4 at the root of a robot arm or other movable member 1 via a mounting bracket 2, a corresponding bearing on the side of the bracket 2 is attached to the outer periphery of the shaft 4. A welding gun mounting device comprising a hard rubber or other elastic member 6 interposed between the hole 5 and the hole 5.