To provide an apparatus and a method for machining fine recessed portions, by which apparatus and method, fine recessed portions having a constant depth with respect to the inside peripheral surface of a cylinder bore can be formed, and its machining cost can be reduced.
The apparatus for machining fine recessed portions comprises a main spindle 3, a holder 10 which is coaxially mounted on a main spindle 2 so as to integrally rotate and axially move, a machining roller 11 having fine protrusions and recesses on its outer peripheral portion, an arm 12 which is arranged on the holder 10 and supports the machining roller 11 so as to rotate about a roller axis arranged in parallel to the main spindle 3, a compression coil spring 20 for pressing the fine protrusions and recesses of the machining roller 11 against the inside peripheral surface Ba of the cylinder bore B, its central axis being coincident with the rotation axis L of the holder 10, by applying a force in the radial direction of the machining roller 11 to the arm 12, a rotary encoder 5 for detecting the rotational speed of the main spindle 3, and a control unit 6 for controlling the radial force from the compression coil spring 20 based on the variation of the rotational speed of the main spindle 3 such that the actual pressing force during machining of the machining roller 11 becomes almost constant.
OTA MINORU
UEHARA YOSHITAKA
NAKAYAMA TATSUOMI
