AUXILIARY DEVICE FOR PROCESSING OF WORKPIECE AND USAGE THEREOF

PROBLEM TO BE SOLVED: To provide an auxiliary device for processing of a workpiece, which can prevent a chattering phenomenon in processing of a workpiece which is relatively long and thin.SOLUTION: There is provided an auxiliary device 3 for processing, which is set in a thin workpiece 1, which is in a corrugated shape and has connected cavities, and used when processing an outer peripheral surface 1f of the workpiece 1. Auxiliary units 3A, 3B, 3C, and 3D comprise: base materials 5 arranged in a longer direction of the workpiece 1; bolts 6 stood on the base materials 5 and having screw parts 6a formed at shaft parts; diameter increase members 7 on which the screw parts 6a of the bolts 6 are threadably mounted, and move up and down as the bolts 6 are rotated; a pair of press members 9, 9 which abut on the diameter increase members 7, and swing in a short direction of the workpiece 1 with a pair of pins 8, 8 provided to the base materials 5 as axes as the diameter increase members 7 move up and down; and springs 10 which press those press members 9, 9 against the side of the diameter increase members 7. The auxiliary units 3A, 3B, 3C, and 3D are set successively in the workpiece 1.