METHOD FOR WORKING DIAPHRAGM OF OIL PRESSURE CIRCUIT BY LASER BEAM

PURPOSE:To work so as to make a smooth projecting shape and to simultaneously harden the work surface by subjecting to piercing the diaphragm used for an oil pressure circuit by adjusting the focus point of a laser beam. CONSTITUTION:The through hole 2 of a diaphragm part is made by using a carbon steel plate 1 and specifying the energy density of a laser beam with adjusting the focus position thereof. Both sides of the plate is worked so that the surface part is made a smooth projection 3 to form a hardened layer 4 over the whole surface on the work cutting part. Owing to the hardening by laser beam having a self-cooling action the need for the coolant of a water, oil, etc., is eliminated and a heat treatment can be performed in the atm. Moreover the heating is local, so the deformation due to the thermal strain and a quenching crack are less.