Friction stir welding method and friction stir welding device

The problem addressed by the present invention is to efficiently and securely bond workpieces to each other by friction stir welding while suppressing labor and man-hours. In order to solve the problem, a friction stir welding method includes a fixing step, a temporary welding step (S2), and a main welding step. In the fixing step, the workpieces (W1, W2) are pressed and fixed to the receiving table by a plurality of spring pins (10) separated from each other. In the temporary bonding step (S2), the workpieces (W1, W2) are spot-bonded to each other by friction stir welding at locations different from the spring pin (10). In the main bonding step, the spot-bonded workpieces (W1, W2) are linearly bonded to each other by friction stir welding. 本发明要解决的问题是，在抑制劳动和工时的同时，高效且牢固地将工件彼此摩擦搅拌接合。为了解决上述问题，一种摩擦搅拌接合方法具有以下所示的固定工序、临时接合工序(S2)及正式接合工序。在固定工序中，利用互相分离的多个弹簧销(10)，将工件(W1,W2)按压并固定在承接台上。在临时接合工序(S2)中，在与弹簧销(10)不同的部位，借由摩擦搅拌接合将工件(W1,W2)彼此点接合。在正式接合工序中，借由摩擦搅拌接合将经点接合的工件(W1,W2)彼此线接合。