| 摘要 |
This invention relates to a cylinder for die casting, which has a dual construction consisting of an inner ceramic cylinder member and an outer metal cylinder member, and which is characterized in that, in order to prevent the bending of the cylinder and the breakage of the inner cylinder member which are ascribed to a difference in the coefficient of thermal expansion between the inner and outer cylinder members, a plurality of bores (24) are formed in a boundary surface between the inner and outer cylinder members (22), (21), whereby the heat insulating characteristics of the cylinder are improved. When the bores are provided in the shape of grooves in the inner surface of the outer cylinder member or the outer surface of the inner cylinder member, the ratio of the width a of each groove to the distance b between two adjacent grooves is set in the range of 1:1-6:1. This enables better heat insulating characteristics to be obtained. |
