Spot welding method

Abstract

A spot welding method including: a main energization step of energizing a pair of opposing electrodes in pressure contact with both outer surfaces of a set of sheets where multiple sheet materials are stacked, thereby to cause melting between facing surfaces of the sheet materials; and a pressing variation step of, prior to the main energization step, causing a pulsation of pressing force applied to the set of sheets from the electrodes. A resin material such as an adhesive or a sealant may be interposed between the facing surfaces of at least a pair of the sheet materials. The period of the pulsation is 0.01 to 0.7 seconds. The amplitude of the pulsation is 10% to 90% with respect to a reference value of the pressing force. The set of sheets may include a first and a second steel sheet, and an aluminum alloy sheet that are stacked in order.

Dependencies are inferred from the claim text.