Electrode device

Abstract

The present invention relates to a water-cooled resistance-welding electrode device that is capable of stably cooling an electrode by constantly circulating cooling water to the vicinity of an electrode tip in an efficient manner. The present invention provides an electrode device having a structure in which a cooling pipe 11 is inserted into the interior of a device body 1 from a bottom side thereof, and cooling water jetted from a tip opening 11a of the cooling pipe 11 cools a cap tip 10 covering a tip of a shank 8, wherein the cooling pipe 11 is attached so that the cooling pipe 11 can freely be moved with respect to the axial direction of the device body 1 and so that the cooling pipe 11 can freely be secured at an arbitrary position. As a result, it is possible to always position the tip opening 11a of the cooling pipe 11 in the vicinity of the cap tip 10 even if the length of the shank 8 is changed, it is possible to reliably cool the cap tip 10, and it is possible to stably maintain the shape of the electrode tip for a long period of time.

Description

technical field [0001] The present invention relates to an electrode device for resistance welding having a structure cooled by cooling water. Background technique [0002] The main cause of poor welding in resistance spot welding is the decrease in current density due to wear and expansion of the tip of the electrode tip. That is, the main reason is that due to the wear and expansion of the tip tip, the area in close contact with the workpiece increases, the current spreads, and the current density per unit area decreases, so the resistance heating value decreases, resulting in poor welding. [0003] As is well known, Joule's heat, which is the basis of resistance welding, is proportional to the square of the current as shown by the calorific value Q=current×current×resistance×conduction time. Here, if the diameter of the tip of the electrode is increased by 10%, the area becomes 1.21 times, and the current density becomes about 80%. According to the above calculation form...

AI Technical Summary

Problems solved by technology

[0009] Regarding the structure described in Patent Document 1, there is a problem that if the length of the handle 52 is different, the distance of the gap between the front end of the cooling pipe 54 and the inner surface of the top cap 53 will be different. The distance between the front end of 54 and the inner surface of the top cap 53 increases, so the cooling performance decreases. In the field operation, there are many types of welding objects, and the conversion process becomes routine. At this time, the handle 52 and the The replacement of the cooling tube 54 on the inner surface of the electrode formed by the top cap 53 becomes cumbersome. Therefore, it is impossible to change the length every time the conversion process is performed. Even if the electrode length is increased due to the conversion process, only the electrode Replacement, so that the cooling water cannot be efficiently circulated near the tip of the electrode, causing the shape of the tip of the electrode to wear and expand earlier than expected, resulting in unexpected welding failures

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