Resistance spot welding device and resistance spot welding method

Abstract

The object of the present invention is to obtain a suitable diameter nugget where no spatter occurs. The present invention relates to a resistance spot welding device that joins specified materials to be welded together, wherein the device is configured with a storage unit, an adaptive control unit, and a pressure control unit, and the storage unit will The time change of the instantaneous heat release per unit volume and the cumulative heat release per unit volume during the test welding are stored as the target value, and the time change of the instantaneous heat release per unit volume during the actual welding is stored as the target value. In the case of a time-varying curve, the adaptive control unit controls the current value or voltage value during energization so that the difference is compensated for during the remaining energization time so that the accumulated heat release per unit volume in actual welding and the target value are stored. The accumulative heat release per unit volume is the same; the pressurization control part controls the pressurization of the material to be welded.

Description

technical field [0001] The invention relates to a resistance spot welding device capable of forming a suitable nugget through an adaptive control welding technique. [0002] Moreover, this invention also relates to the resistance spot welding method which performs welding using the said resistance spot welding apparatus. Background technique [0003] In general, resistance spot welding, which is a type of lap resistance welding, is used to join stacked steel plates. [0004] This welding method is a method of clamping two or more superimposed steel plates with a pair of electrodes from above and below, and while applying pressure, pass a high welding current between the upper and lower electrodes for a short time to join; A dot-shaped weld is obtained by resistive heat generation caused by flowing a high welding current. This point-shaped welded portion is called a nugget, and is a portion where the two steel sheets melt and solidify at the contact point of the steel sheet...

AI Technical Summary

Problems solved by technology

[0022] However, in the resistance spot welding performed by the control device of the resistance welding machine described in Patent Document 1 and the welding condition control method of the resistance welding machine described in Patent Document 2, the temperature of the nugget is estimated based on a heat conduction model (heat conduction simulation) or the like, Therefore, complicated calculation processing is required, so that there is a problem that not only the configuration of the welding control device becomes complicated, but also the welding control device itself becomes expensive.

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