To provide an apparatus for working fine recessed parts with which the fine recessed parts are formed with regular arrangement in the arrangement in a direction along the axial line of circular surface to be worked and the fine recessed parts having the desired shape are highly accurately formed by eliminating the effect caused by a spring-back of a material.
The apparatus for working fine recessed parts is provided with: a form-roller 11 having projecting part 11a for forming the fine recessed part; an arm 12 for supporting the form-roller 11 freely rotatably with a rotating-shaft 14 crossing the inner circumferential surface Ba at the right angle; a tool holder 10; a helical compression spring 18 for press-contacting the form-roller 11 with the inner circumferential surface Ba; and a table 4 for shifting a cylinder block CB; wherein the projecting part of the form-roller has the shape assuming the spring-back rate of the material of the cylinder block CB and thus; the fine recessed parts P are formed with the regulating arrangement and the effect caused by the spring-back is eliminated.
OTA MINORU
UEHARA YOSHITAKA
