JPS61165281A - Spot welding device - Google Patents

Abstract

PURPOSE:To permit the spot welding of steel plates coated with a primary rust preventive paint with respect to the constitution of a spot welding device by providing local heaters adjacently to a pair of pressurizing and current conducting electrodes for welding. CONSTITUTION:The local heaters 6, 7 are provided adjacently to a pair of the pressurizing and current conducting electrodes 3, 4 for spot welding. The painted steel plates 5 are held in place between the preheaters 6 and 7 and the primary rust preventive paint at the intended welding point is burned by heating. The electrodes 3, 4 are then moved to the burned point and the steel plates 5 are spot-welded. The spot welding device having the capability of the spot welding of the painted steel plates is thus obtd.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a spot welding device.

[Conventional technology]

Conventional spot resistance welding has been applied only to locations where the metal surface of the conductor is exposed. On the other hand, the materials to be welded are sometimes coated with a primary anti-rust coating. In this case, the anti-rust coating is an insulator and cannot be welded using the usual mechanism of resistive heat generation by applying electricity.

[Problem that the invention seeks to solve]

Marine structures are generally manufactured using materials coated with a primary anti-rust coating, and spot resistance welding of these types of materials may be more advantageous than arc welding. Therefore, an object of the present invention is to provide a welding device that enables such spot resistance welding.

[Failure to solve the problem]

The present invention relates to a spot welding device characterized in that it is equipped with a local preheater adjacent to a pair of pressurizing and energizing electrodes for spot welding.

That is, the present invention is characterized by having a configuration in which not only the conventional pressurizing/current-carrying chip but also a preheating chip (for incinerating the coating film) is attached in front of it.

[For production]

The apparatus of the present invention will be explained below based on the drawings.

FIG. 1 is a schematic diagram of a spot welding device according to the present invention.
This shows the state in which the upper and lower electrodes are sandwiched between the materials to be welded. Each symbol in the figure represents the following energization.

1; Upper support arm; 2; Lower support arm; 3; Upper current-carrying electrode;
4; Lower current-carrying electrode, 5; Material to be welded, 6; Upper preheater, 7
Lower Preheater When welding progresses in the direction of the arrow in FIG. 1, the plate material is first clamped with electrodes 3.4, as in the conventional spot welding machine. In this case, the material to be welded 5 is coated with an insulator (secondary anti-corrosion paint), so in this state, the electrode 3,
Power cannot be applied between 4. Therefore, the preheater 6.7 heats a local part of the sandwiched workpiece 5 to burn out the primary antirust paint in that part. Thereafter, the electrodes 3 and 4 are moved to the burnt out location and pressurized. Here, since the already applied film has been destroyed by heat, current can be passed between the electrodes 3 and 4, and resistance welding can be performed.

Although the preheaters shown in FIG. 1 are arranged at the top and bottom, it is also possible to heat only one side depending on the thickness of the board, paint, etc.

In addition, when welding continuously at a fixed pitch, by separating the preheater and electrode by the required pitch, it is possible to bake the coating film at the next welding point before welding one point. , continuous welding becomes possible. Further, the distance between the electrode and the preheater may be slidable mechanically of the device. Furthermore, as a heating method, methods such as electric resistance heating, laser heating, and gas flame heating can be used.

〔Effect of the invention〕

Regarding spot resistance welding equipment, a local preheater is installed before welding separately from the pressurizing and energizing electrodes, and the primary rust-preventive coating, etc., which is an insulator (rust-preventing oil By burning out the dirt and grime, it becomes possible to conduct electricity, making it possible to weld materials that were previously impossible.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a spot welding apparatus according to the present invention. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] A spot welding device characterized by being equipped with a local preheater adjacent to a pair of pressurized and energized electrodes for spot welding.