JPH0731905Y2 - Electrode structure of spot welding gun - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode structure for a spot welding gun. More specifically, it is designed so as not to damage the electrode holder when replacing the electrode tip.

[0002]

2. Description of the Related Art When a welding gun is inserted into a narrow space for welding, the gun arm and the work interfere in the narrow space.
In order to avoid this, it is necessary to make the height (H) of the electrode tip 43 attached to the tip of the gun arm as low as possible. Therefore, in general, for example, as shown in FIG.
An electrode in which the electrode holder 41 and the tip insertion portion 42 are integrated is used. In this case, a cooling water path 44 that penetrates the shank tip is provided inside the electrode holder. Further, as shown in FIG. 3, for example, the electrode holder 31
The electrode chip 33 in the mounting hole 34
A fitting portion 35 having a taper-shaped base is inserted into the cooling water path 36 of the electrode holder and the circumferential groove 3 provided around the base.
An electrode structure that communicates with 7 is known.

However, in all of these conventional devices, when the electrode tip is replaced, the electrode chip is removed with a great force, so that the taper surface of the fitting portion may be damaged or damaged. This causes water leakage and electric contact damage. To avoid this, the entire electrode holder is often replaced with a new one. Since the electrode tip is frequently replaced as a consumable item, there is a non-negligible problem that the expensive electrode holder must be replaced each time. For this reason, in the former case, if the hardness is to be increased only in the tip insertion portion, an expensive material such as beryllium copper is used for the entire electrode holder.

[0004]

The problem to be solved by the prior art is that in the prior art, if the fitting portion is damaged during the replacement of the electrode tip, the tip holder must be replaced not only but the electrode holder must be replaced as a whole. That is the point.

[0005]

SUMMARY OF THE INVENTION The present invention is designed so that only the tip of an electrode can be replaced without damaging the fitting part of the electrode holder. The rear portion of the shank is fitted into the through hole, and the cooling water paths of IN and OUT provided inside the electrode holder at this fitting portion communicate with the cooling water passages penetrating the inside of the shank. An electrode structure in which a cap chip is fitted in a taper-shaped chip insertion part formed in the front part, and a through hole for inserting a shank into the tip of the electrode holder of the fitting part, and an inner diameter of this through hole The outer periphery of the shank to be inserted into the shank is removably engaged with each other with a tapered wedge surface.

[0006]

1 is a cross-sectional view of an essential part of an embodiment of the device of the present invention, wherein 1 is an electrode holder attached to the gun arm of a spot welding gun, 2 is a shank inserted into the electrode holder, 3 is a cap chip that fits on the shank.

A through hole 4 having a size into which the shank 2 can be inserted is provided at the tip of the electrode holder 1, and the inner diameter of the hole is a tapered wedge surface having a gentle slope. The shank 2 is engaged with the insertion portion 7 formed on the outer periphery of the rear portion of the shank 2 and having a taper-shaped wedge surface, and a force due to the wedge action acts on the fitting surface to firmly fix the two. A drill hole 5 is formed inside the electrode holder 1 to form a cooling water path for IN and OUT. Notches a and b are provided on both sides of the shank insertion portion, and a cooling water path 6 is provided through which the inside of the shank is cut out and penetrates from the notches a and b. The cooling water flowing through the gun arm is fitted into the tip insertion portion 8 having a taper-shaped wedge surface with a high slope formed at the tip of the shank 2 and the cooling water path 6 of the shank 2 from the hole 5 inside the electrode holder.
It circulates and flows to the cap chip 3.

[0008]

As described above, according to the present invention, a through hole for inserting a shank is provided at the tip of the electrode holder of the spot welding gun, and the inner diameter of this through hole and the outer periphery of the rear part of the shank inserted therein are inclined. Since the taper-shaped wedge surface with a low end is detachably engaged, when replacing the cap tip, even if the fitting part between the shank and the cap tip is damaged, if the shank is replaced, it will be the same as before. It is not necessary to replace the entire expensive electrode holder, and the cost can be reduced by using only the shank of a hard material without making the entire electrode holder of an expensive hard material. Further, since the height (H) of the electrode can be lowered, the interference of the work can be avoided even at a narrow welding position, and the workability and versatility of the welding can be remarkably improved.

[Brief description of drawings]

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

FIG. 2 is a front view showing the structure of the shank of the present invention,
The same figure (A) is a shank front view, (B) is a right side surface, (C) is a left side surface, and (D) is d of the same figure (A).
FIG.

FIG. 3 is a cross-sectional view showing a conventional electrode structure.

FIG. 4 is a schematic view showing another conventional electrode structure.

[Explanation of symbols]

 1 Electrode holder 2 Shank 3 Cap tip (electrode tip) 4 Through hole 5 Drill hole 6 Cooling water path

Claims (1)

[Scope of utility model registration request] 1. A rear part of a shank is fitted into a through hole provided in an electrode holder of a spot welding gun, and IN and OUT cooling water paths provided inside the electrode holder at the fitting part and an inside of the shank. An electrode structure in which a cap chip is fitted in a taper-shaped tip insertion portion formed in the front portion of the shank in communication with each cooling water passage that penetrates through the tip of the electrode holder at the fitting portion. An electrode structure for a spot welding gun in which a through hole into which a shank is inserted and a rear outer periphery of the shank inserted into the inner diameter of the through hole are detachably engaged with each other with a tapered wedge surface.