DRILLING OF FIXED HOLE OR VALVE HOLE IN DISH OR RIM OF WHEEL FOR AUTOMOBILE

摘要

PURPOSE: To form countersunk portions of comparatively large diameters on both the surfaces of a wheel without performing refastening of the wheel by revolving a mounting part by a prescribed angle with the axial line of the wheel as a center, punching a second through hole by a tool and countersinking this second through hole. CONSTITUTION: A tool 160 is retracted outward in a radial direction and an axial direction, a mounting part is revolved by an angleαwith an axial line perpendicular to an axial line of a wheel as a center and a second through hole having the smallest diameter in a hole each time is punched. Next, the second through hole on a first surface 135 having a first section 140 of a larger diameter D1 is countersunk.