Patent ID: 8502105
Filing Date: 2013-08-06
Classification: B23K,C09J,Y10T

Abstract:
1. A method of joining dissimilar metal plates of an aluminum alloy plate and a plated steel plate by means of adhesion of an adhesive and spot welding, the method comprising: a lapping step of lapping the aluminum alloy plate and the plated steel plate via the adhesive; a pre-pressuring step of clamping the aluminum alloy plate and the plated steel plate between the pair of electrodes and applying pressure therebetween; a pre-heating step of clamping both of the metal plates that have been lapped in the lapping step between a pair of electrodes for spot welding and applying pressure thereto, and applying a current between the pair of electrodes; a cooling step of pressurizing, after the pre-heating step, where both of the metal plates are pressed between the pair of electrodes at a pressing force which is higher than that at the start of the pre-heating step in a state where conduction between the electrodes is stopped, and continuing this pressurization over a predetermined cooling time; and a welding step of pressurizing, after the cooling step, where both of the metal plates are pressed between the pair of electrodes at a pressing force which is higher than that at the start of the pre-heating step, and both of the metal plates are welded by applying a current which is higher than the conduction current value in the pre-heating step between the pair of electrodes, wherein the pressing force of the electrodes is set to a first pressing force during a predetermined period from the start of the pre-heating step, the pressing force is increased to a second pressing force that is greater than the first pressing force in the middle of or at the end of the pre-heating step, and the pressurization is continued with the second pressing force until the completion of the cooling step and the welding step; and wherein the pressing force in the pre-pressurization step is set to be greater than the first pressing force.