JPS5823494Y2 - welding machine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a resistance welding machine, and mainly relates to improvements in its electrode components.

Conventionally, the electrode components of this type of welding machine, namely the tip and the outer surface of the shank and arm, are largely uncoated.

If such an electrode comes into contact with the workpiece at a point other than the welding point, the efficiency will decrease due to short circuit.

Therefore, in some cases, there are insulating coatings, but the coating can easily peel off or wear out in a short period of time if the edges of the workpiece come into contact with it. Met.

In order to improve this point, if a thick layer is formed in consideration of the peeling and abrasion of the coating, there will be a problem in that the work will be slow and the workability will be poor.

Apart from this, even if the workpiece does not come into contact with the current-carrying part other than the welding part when the current is applied and a short circuit does not occur, depending on the workpiece, during the positioning operation of the welding part, the electrode There are cases where a specific part is repeatedly contacted, and the contact part may wear out and unexpected accidents such as cooling water leakage may occur.

Therefore, the present invention aims to provide an electrode component or a welding machine part having a relatively thin coating layer with excellent insulation properties and wear resistance, thereby obtaining a welding machine in which the above-mentioned drawbacks are improved. That is.

This invention will be explained below based on the illustrated embodiments.

Ia and 1b in the figure are opposite electrodes of the spot welding machine. In particular, the structure itself is almost the same as the conventional one, and the workpieces 2a and 2b are welded at the welding point 3a of the electrode.
, 3b, and welding can be performed by applying current.

The detailed structure of the electrodes is shown only for one electrode 1b, and is omitted because the other electrode 1a is substantially the same.

The electrode 1b consists of a tip 4 and a shank 5, and an arm 6
Is it supported by a cooling water passage inside? a and 7b are formed.

The difference from conventional welding machines is that coating layers 8, 9, and 10, whose thicknesses are exaggerated in the figure, are provided on the outer surfaces of the tip 4, shank 5, and arm 6, respectively.

The coating layers 8, 9, and 10 are sprayed with white alumina formed by plasma spraying to a thickness of 0.3 to 0.5 mm.

Since the plasma welding technique is well known, its explanation will be omitted.

The spot welding machine in which the white alumina spray coating layer is provided on the tip 4, shank 5, and arm 6 can be used, for example, when welding the workpieces 2a and 2b as shown in the figure. The effect is exerted in the areas 11 and 12 that are easily touched.

That is, the coating layers 8, 9, and 10 have excellent insulating properties and excellent wear resistance, and even though the thickness of the coating layer is thin, it maintains its insulating effect for a long period of time, and the inner side of the coating layer prevent wear of the base material.

Therefore, this spot welding machine prevents short circuits even if the workpiece comes into contact with the electrode at a part other than the welding point, and also prevents local wear in that part, making it significantly more effective than conventional spot welding machines. It has been improved.

In the above embodiments, the coating layers 8, 9, and 10 were formed by plasma spraying white alumina, but in addition to white alumina, gray alumina, alumina, etc. can also be used to obtain the same effect, and these can also be used as appropriate. It may be a composite mixed with titanium dioxide or a composite mixed with these and titanium dioxide, and in general, a similar effect can be expected if it is a ceramic.

In the above embodiment, the coating layer was formed on the arm other than the electrode, but it should be provided on the arm as necessary, and it should be provided on at least the electrode component parts and the shank. be.

As described above, according to this invention, by forming a thin insulating coating layer with excellent wear resistance on the outer surface of the electrode component, welding current can be reduced due to short circuits without deteriorating workability. It is possible to provide a welding machine that can prevent this for a long period of time, and can also prevent local wear of the electrode portion that comes into contact with the workpiece other than the welding point.

[Brief explanation of drawings]

The figure is a longitudinal sectional side view of the main parts of an embodiment of this invention. la, 1b... counter electrode, 2a, 2b...
...Workpiece, 3a, 3b... Electrode welding point,
4...Tip, 5...Shank, 6.
...Welding machine arm, 7a. 7b... Cooling water passage, 8, 9, 10...
・Covering layer.

Claims (1)

[Scope of utility model registration request] In a welding machine that applies current to a workpiece while holding it between a pair of electrodes, a coating layer is provided on the outer surface of one or both of the electrodes, and this coating layer is a layer formed by plasma spraying ceramic. A welding machine characterized by: