To provide an apparatus and a method for working very small recesses capable of regularly forming very small recesses on an inner circumferential surface with high accuracy when forming the very small recesses on the inner circumferential surface of a circular hole of a work, and capable of enhancing the productivity and reducing the manufacturing cost.
In the working apparatus for forming very small recesses on an inner circumferential surface of a cylinder bore B, a working roller 12 is rotatably mounted on a tip part of a bent arm 11 connected to a spindle 1 side and having a hinge part via a roller shaft 18, and a torsional coil spring 13A to apply the load onto the inner circumferential surface to the working roller 12 abutted on the inner circumferential surface of the cylinder bore B together with the expansion or contraction of the bent arm 11 is provided on the bent arm 11. The very small recesses can be regularly and efficiently formed with high accuracy, the productivity is enhanced, and the manufacturing cost is reduced.
NAKAYAMA TATSUOMI
OTA MINORU
