Manufacturing method for double tube having a hole formed therein, and mold for implementation thereof

Abstract

To provide manufacturing method for a double tube having a hole formed therein and a mold for implementing such method, which reduce the time required for manufacturing, do not leave shavings in the gap between the outer tube and the inner tube, and offer highly accurate hole positioning. The manufacturing method for a double tube having a hole formed therein pertaining to the present invention uses a mold in which a punch is located in at least one of the split mold halves that form the outer circumferential surface, an indentation is formed by drawing the punch into the mold, and fluid pressure is applied between the outer tube and the inner tube of the double tube located within the mold to form a hole in the circumferential wall of the outer tube via such indentation. Furthermore, the punch is placed in the mold in a watertight fashion.

Dependencies are inferred from the claim text.