| 摘要 |
PURPOSE:To enhance controlling precision of the temp. of the whole die by providing an unevenness on the inner wall surface of a water pipe and increasing the surface area of the inner wall surface. CONSTITUTION:The unevennesses of the inner wall surface of a water pipe are constituted of four pieces of grooves 10 formed parallel to the vortex shape of the water pipe 2 and therefore fluidity of a medium for controlling the temp. especially is not lowered. For example, in the case of molding a base plate for an optical disk of 13cm, the water pipe 2 having about 5-10mm breadth is ordinarily adopted. Depth of the groove 10 may be regulated to about 0.1-2.0mm preferably about 1.0-2.0mm. Further breadth of the groove 10 may be regulated to about 0.5-3.0mm preferably about 0.5-1.0mm. In such a way, an injection-molding die for the base plate of the optical disk is provided with the unevenness for controlling the temp. on the inner wall surface of the water pipe and the surface area of the inner wall surface is increased and therefore controlling precision of the temp. of the die is excellent. |
