Compulsive air-cooling lower electrode specially used for resistance projection welding of annular nut

Abstract

The invention discloses a compulsive air-cooling lower electrode specially used for resistance projection welding of an annular nut, which comprises three parts consisting of a lower body of a lower electrode holder, an upper body of the lower electrode holder, and an electrode cap. The lower body of the lower electrode holder adopts a combined cooling way of water cooling and compulsive air-cooling; and the upper body of the lower electrode holder and the electrode cap adopt the compulsive air-cooling. The way of compulsive air-cooling through compressed air is adopted to prevent splashes in the nut from damaging threads during welding, improve the service life of the electrode, and reduce the adherence of the splashes. A locating pin is automatically reset through the pressure generated by the compressed air and a spring. A conical locating pin is adopted to improve the locating precision of the nut, and improve the generality of the locating pin when nuts of different diameters are welded. The compulsive air-cooling lower electrode specially used for the resistance projection welding of the annular nut has a simple structure, is convenient to operate, is easy to obtain stable welding quality during welding, and has more ideal engineering practicability.

Description

technical field [0001] The invention belongs to the welding technical field of automobile manufacturing, and relates to a special lower electrode used in the resistance projection welding process of a large ring nut and a metal plate (coated steel plate or carbon steel plate). Background technique [0002] A large number of nuts of various sizes are used in the manufacture of automobile bodies, and a considerable part of them requires welding to connect the nuts with the sheet metal. The welding process adopted not only requires the welded joint to have sufficient torsional strength, but also requires ensuring that the threaded hole and the light hole of the metal plate have a certain coaxiality. This has greater difficulty in actual welding, especially for the welding of large nuts. At present, the resistance projection welding process is mostly used to weld such nuts, which belongs to multi-point projection welding at local positions, and the electrodes are generally in t...

AI Technical Summary

Problems solved by technology

[0003] (1) The positioning accuracy of the coaxiality of the nut and the light hole of the metal plate is poor;

[0004] (2) The versatility is poor, and the nuts of different specifications need to replace the electrodes, which affects the production efficiency;

[0005] (3) Most of the positioning pins are fixed. During welding, under the impact of the upper electrode, the inner thread of the nut and the positioning pin may be damaged, which will affect the positioning accuracy and welding quality;

[0006] (4) The cooling water of the lower electrode is connected to the positioning pin. When the electrode is used for a long time and the seal between the electrode and the positioning pin is poor, it is easy to cause water leakage at the positioning pin;

[0007] (5) The spatter during welding is easy to stick to the internal thread of the nut, causing thread damage and affecting the assembly quality

In addition, splashes may also cause the positioning pin and the nut to stick together, damaging the positioning pin and the nut

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