| 摘要 |
A friction stir spot welding method using a cylindrical pin member configured to rotate about an axis and be advanceable and retractable in the axial direction, and a tubular shoulder member configured to surround the pin member, rotate coaxially with the pin member, and be advanceable and retractable in the axial direction in a state where the pin member and the shoulder member are advanceable and retractable, to weld an object to be welded having a front surface facing the pin member and the shoulder member by partial stirring, the method comprising: controlling advancement and retraction of the pin member and the shoulder member, an absolute value of a tool average position Tx is defined by: Ap.cndot.Pp + As.cndot.Ps = Tx, where Ap is a cross-section area of a front end surface of the pin member, As is a cross-section area of a front end surface of the shoulder member, Pp is an insertion depth of the pin member inserted from a front surface of the object to be welded, and Ps is an insertion depth of the shoulder member inserted from the front surface of the object to be welded, Pp and Ps represent insertion depths defined from a insertion depth reference point; and adjusting at least one of Pp and Ps such that Tx becomes substantially zero. |
