Resistance spot welding device, combination electrode and resistance spot welding method

A kind of resistance spot welding device, it is used to carry out resistance spot welding to board group (1), the board group (1) includes multiple metal plates (2A, 2B) that stacking is got up, resistance spot welding device has a pair of of combination electrode (10,20), which is oppositely disposed in the mode between being clipped in board group (1).Each combination electrode (10,20) includes: electrode body (11,21), is rodlike, and top end face contacts with board group (1) and is pressed against board group (1)；And the rigid body (12,22) of electric conductor, there is the through hole (12b, 22b) of power supply polar body (11,21) insertion, and top end face contacts with board group (1) and is pressed against board group (1)；Elastomer (13,23), the rear end of itself and rigid body (12,22) is connected, and applies press pressure to rigid body (12,22) with the pressing to board group (1) of electrode body (11,21) and rigid body (12,22).Thereby, it is possible to improve strength of welded joint while expanding and being applicable in current range.