To provide a device for forming minute recessed parts which can form minute recessed parts on the circumferential face of a workpiece with high precision and cuts down processing costs.
The device for forming minute recessed parts is equipped with a pair of forming rollers 13A and 13B which are different in diameter, a roller supporting member 12 on which both forming rollers 13A and 13B are placed coaxially in parallel, and a tool holder 10 which holds the roller supporting member 12 via a pivot shaft 11 so as to freely oscillate. The tool holder 10 is placed such that both forming rollers 13A and 13B stand in line in the direction of the center line of the inner circumferential face Ba. The minute recessed part forming device is also equipped with a compression coil spring 16 which presses both forming rollers 13A and 13B against the inner circumferential face Ba, and a main shaft 3 which rotates a cylinder bore CB and the tool holder 10 relatively round the center line of the inner circumferential face Ba so as to rotate the form rollers 13A and 13B along the inner circumferential face Ba, whereby the form rollers 13A and 13B are designed to be pressed against the inner circumferential face Ba at a given angle of inclination at all times.
OTA MINORU
UEHARA YOSHITAKA
