METHOD FOR CENTERING METALLIC MOLD

PURPOSE:To enhance the transverse misalignment accuracy and parallelism of a metallic mold consisting of an upper mold and lower mold by forming the plane parts provided to the outside circumferential side faces of the metallic mold flush with the same plane. CONSTITUTION:The plane parts 15a, 15b and 17a, 17b which are the two reference planes for centering are notched and formed simultaneously in the molding of the outside circumferential side faces of the upper mold 15 and the lower mold 17 and a lens forming part. The upper mold 15 and lower mold 17 having the plane parts 15a, 15b and 17a, 17b are imposed on a V-shaped base plate 31 of a mold mounting jig 30 imposed on a stationary surface A. The plane parts 15a, 15b and 17a, 17b of the upper mold 15 and lower mold 17 are positioned in the die clamped state to the V-shaped reference planes 31a, 31b formed on the inside surface of the base plate 31. The circumference of the upper mold 15 and lower mold 17 is gripped by a V-shaped retaining member 32 hinged to one end of the base plate 31 and after the free end 32a thereof is fastened to the other end of the base plate 31 by a lock bolt 33, the molds 15 and 17 are clamped by a tap bolt 34 held at the peak part 32a of the member 32. The plane parts 15a, 15b and 17a, 17b are pressed and fixed to the reference planes 31a, 31b of the base plate 31 by a push bar 35 which is projected when the bolt 34 is tightened.