Patent ID: 7290695

Claim:
A friction stir welding apparatus configured to spot weld an object, comprising: a base fixed at a predetermined position; a tool holding jig to which a welding tool is mounted, said tool holding jig being installed on said base rotatably about a reference axis and movably along said reference axis; tool rotation driving means for rotating said tool holding jig about said reference axis; tool movement driving means for moving said tool holding jig along said reference axis; positioning means, which is installed on said base, for positioning an object to be welded with respect to said reference axis; and holding means for holding said object to be welded with respect to said base, said positioning means positioning the holding means, wherein said holding means has a backing member for supporting a part of said object located on said reference axis from a side opposite to said welding tool, and the backing member and the tool holding jig remain axially aligned throughout a spot welding process; and an operation pedal which outputs a welding start instruction from an operator.