TH73522B - Resistance spot welding method - Google Patents

Abstract

What is presented as Resistance spot welding method to connect parts. To be welded, which is a large number of overlapping sheet metal, including dividing the current pattern into two or more two stages for welding; Before the actual welding Do the retention test welds, for each piece as a target value, the time variation of The instantaneous amount of heat that is generated per unit volume and the amount of cumulative heat that is generated Up per unit volume Calculated from the electrical properties Between electrodes when creating a suitable nugget area by passing current with constant current control; And later do the actual welding Start welding by using Graph of time variation of the instantaneous amount of heat, which Is generated per unit volume obtained by standard test welding, and when the The time of the instantaneous amount of heat generated, deviates during any step from the time variation curves by one difference, is adjusted to control the passing amount. Current to compensate for the difference between the remaining welding time in the above step. So that the cumulative volume of heat generated in welding actually matches the amount of cumulative heat that is A pre-determined test weld, where two or more steps for the welding process include the process of maintaining the current path between the sheet metal directly below the electrode and the subsequent stages of the welding process. Create a welding area with a defined diameter and a welding interval time is provided during these steps, so this method provides a good weld melt area without splashing. ) Even within welding conditions Any special type:

Claims (2)

1. Resistance spot welding method to connect parts to be welded by squeezing and pressing parts. Between the pair of electrodes and the passage of electricity, that piece is a large number of overlaid metal plates. Which is a composite method: splitting the current pattern into two or more than two stages for welding; Before the actual welding The storage test is performed for each piece as a target value, the time variation in the instantaneous amount of heat generated per unit volume and the cumulative heat generated per unit volume. Calculated from the electrical properties Between electrodes When creating a suitable nugget area by passing current with constant current control; And later do the actual welding Start welding by using Graph of time variation of the quantity The instantaneous heat is generated per unit volume obtained by the test weld as a standard, and when the time variation of the transient amount of heat generated deviates during any step from the time variation curve. By one difference, the control was made to Control the current throughput to compensate for the difference between the remaining welding time. At such a step so that the cumulative heat volume which is actually generated in the welding actually matches the volume Accumulated heat generated that is predetermined in a test weld where two or more steps are required for the weld. Included Stages of treatment The current path between the metal plates is directly below the electrode and the later stages of its formation. A weld welding zone with a defined diameter and a welding interval time is provided during the treatment process. The current path between the metal plates is directly under the electrode and Later stages of creation Welding melting area with a defined diameter 2. Method for claim 1, where the cooling time of the welding is one or more cycles and ten or more cycles.