INJECTION COMPRESSION MOLDING DIE ASSEMBLY

摘要

PURPOSE:To make it possible to obtain excellent lens face accuracy by a structure wherein the side faces of each cavity are made of heat insulating materials interposed between core blocks and retainer plates, each of which holds the core block, and further cooling holes are axially, symmetrically provided equidistantly from the optical lens faces in both the core blocks. CONSTITUTION:A fixed mold 8A, in which a fixed mold core block 20 is provided through a fixed mold bushing 19 made of heat insulating material in a fixed frame 18, and a movable mold 9A, in which a core block 11A for compression is slidably provided through a movable mold bushing 22 made of heat insulating material in a movable frame, are provided opposite to each other. Cooling holes 25 and 26, the diameters of which are equal to each other and which respectively are located equidistantly from the lens faces which oppose to the respective cooling holes, are provided on the center axis 1a of a cavity 1 formed by the fixed mold core block 20 and the compression type core block 11A. As a result, the temperature distribution of the resin in the cavity 1 can be made axially symmetrical and the molding shrinkages of the resins at the lens faces can be equalized and the molding excellent in axial symmetricalness and face accuracy can be realized.