| 摘要 |
The member support (30) of a friction stir spot welding device has: a backing piece (31) having a bearing surface (33) that contacts a member (10) being welded; and a supporting body (35) that supports the backing piece (31) such that the backing piece tilts in a slaved tracking manner in response to the tilting of the member (10) being welded, which is in contact with the bearing surface. With the backing piece (31), the amount of change (´) in the position of the bearing surface on the line extension of the central axis of rotation, when the bearing surface is in the reference state perpendicular to the central axis of rotation (Ac) of a rotary tool (20) and when the bearing surface tilts in a slaved tracking manner in response to the tilting of the member being welded, is equal to or less than a predetermined dimension (ds) with which the shoulder part (25) of the rotary tool is embed-ded with respect to the part being welded. |
