JPH09248679A - Grinding device for electrode tip in resistance welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a horizontal twisting load and to grind both electrode tips simultaneously by positioning back to back two rotary blades with a half side knife and rotating each blade inversely to each other at the same time. SOLUTION: With a power transmission mechanism incorporated, in which rotary blades 9, 10 with a half side knife are placed back to back and in which the blades are simultaneously rotated inversely to each other, the device is capable of reducing grinding time by grinding both electrode tips 6, 7 at the same time with a spot welding gun closed, and also capable of offsetting a horizontal twisting load on the robot arm mechanism holding the gun arm and the gun. This device, compared with conventional systems of grinding electrode tips one side at a time, further reduces the twisting load on the gun and the robot arm, making the load nearly zero theoretically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode tip polishing apparatus for polishing and shaping the tip of an electrode tip of a resistance spot welding machine.

[0002]

2. Description of the Related Art In a conventional electrode tip polishing apparatus, as shown in FIG. 2, an air or electric motor M supported by a mount 1 and a spur gear 3 of one double-edged rotary blade 2 and the output of the motor are usually used. A single double-edged rotary blade 2 is rotated in one direction as shown by arrow A through a power transmission mechanism in which a spur gear 5 of a shaft 4 is meshed, and a robot or the like uses an electrode tip 6 of the spot welding gun 6 or an electrode. The tip 7 was pressed from above and below, and the tip portion of the electrode tip, which had worn out and had an enlarged tip diameter, was shaped.

[0003]

When one double-edged rotary blade 2 polishes the electrode tip 6 and the electrode tip 7 at the same time, a force acts to rotate both electrode tips, and the tip of the electrode tip is rough or vertical. If it is not pressed against the blade, the blade of the double-edged blade is not sharp, or if the blade bites into the electrode tip, a large lateral torsional load is applied to the gun arm that supports the electrode tip and the robot arm that holds it.

Although one rotary blade usually has blades on both sides, when the spot welding gun is closed and both electrode tips are polished at the same time, the rotary blade contacts the electrode tip and the gun arm or robot arm holding the electrode tip during polishing. Since the torsional load is large, it is necessary to increase the strength of the gun arm especially in the lateral direction, and it is necessary to use a highly rigid robot for holding the gun. Even in that case, the mechanical parts of the gun and robot arm subject to a large torsional load are liable to rattle, which may shorten the service life.

Therefore, in order to reduce this torsional load, the electrode tips are usually polished one by one. In this case, although the torsional load applied to the spot welding gun and the robot arm can be halved, the polishing time is doubled and the production There was a problem of inhibiting sex.

[0006]

The present invention has been made to solve the above problems, and in an electrode tip polishing apparatus for polishing and shaping the electrode tip end of a resistance spot welding machine, the electrode tips on both sides are Provided is a pair of rotating blades for polishing, and simultaneously rotating both rotating blades in opposite directions to polish both electrode tips at the same time, to provide an electrode tip polishing apparatus for a resistance welding machine.

Since two rotary blades each having a single-sided blade are installed back to back and a power transmission mechanism for simultaneously rotating the rotary blades in opposite directions is incorporated, the spot welding gun is closed. Thus, it is possible to simultaneously polish both electrode tips to shorten the polishing time and cancel the torsional load applied to the arm mechanism such as the robot holding the gun arm and the spot welding gun. This reduces the torsional load applied to the gun and robot arm more than when polishing the electrode tips one by one as in the past, and in principle can approach zero.

Thus, it is possible to use a gun or robot having a lower rigidity while reducing the polishing time of the conventional electrode tip by half, and to extend the service life because the torsional load applied to those mechanical parts is extremely small. You can

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the principle of the electrode tip polishing apparatus of the present invention is that an air or electric motor M is supported on a gantry 1, and a main bevel gear 8 is attached to an output shaft 4 of the air or electric motor M. This main bevel gear 8
And a pair of single-edged rotary blades 9 having a single-sided blade, a driven gear 11 and a driven gear 12 respectively installed on the single-edged rotary blade 10, mesh with each other, and one side of each driven gear 11, 12 is It is supported by meshing with a driven bevel gear 13 which is rotatably supported on the side opposite to the bevel gear 8.

When the output shaft 4 of the electric motor M is rotated, the main bevel gear 8 causes the driven gears 11 and 12 of the single-edged rotary blade 9 and the single-edged rotary blade 10 to rotate in the directions indicated by arrow A and arrow B, respectively. A robot or the like presses the electrode tips 6 and 7 of the welding gun from above and below to enter the dressing. During this time, the electrode tips 6 pressed from above and below due to the reverse rotation of the single-edged rotating blades.
And, the dressing of the tip portion of the electrode tip having the enlarged tip diameter is performed in a short time while the lateral torsional load on the electrode tip 7 is offset.

[0011]

As described above, according to the apparatus of the present invention, two rotary blades each having a single-sided blade are installed back to back, and a power transmission mechanism for simultaneously rotating the rotary blades in opposite directions is incorporated. Therefore, when polishing both electrode tips at the same time with the resistance spot welding machine and spot welding gun closed, it is possible to cancel the twisting load applied to the lateral mechanism on the arm mechanism such as the robot, and to reduce the polishing time. It is possible to shorten the use of guns and robots with low rigidity and extend their life.

[Brief description of drawings]

FIG. 1 is a principle view showing an embodiment of the device of the present invention.

FIG. 2 is a principle diagram showing an embodiment of a conventional device.

[Explanation of symbols]

 1 ... ・ Mounting stand 6 ・ ・ ・ Electrode tip 7 ・ ・ ・ ・ ・ ・ Electrode tip 8 ・ ・ ・ ・ Main driven gear 9 ・ ・ ・ ・ Single-edged rotating blade 10 ・ ・ ・ ・ ・ ・ Single-edged rotating blade 11 ・ ・ ・Gears 12 ··· Driven gears 13 ··· Driven bevel gears

Claims (1)

[Claims] 1. An electrode tip polishing apparatus for polishing and shaping the tip of an electrode tip of a resistance spot welding gun, in which a pair of rotating blades for polishing the electrode tips on both sides and the blades are simultaneously rotated in opposite directions. An electrode tip polishing machine for a resistance welding machine, which is capable of polishing both electrode tips at the same time.