Double pipe and coupling structure for the pipe

摘要

When the common part of the outer pipe and the inner pipe is worked with the pressing-type punching-out work for connecting with the inner pipe, there occurs no possibility that any disadvantage caused by the punched-out debris is generated.;An inner pipe is arranged at the inside of an outer pipe. Each part of the outer pipe and the inner pipe is partially made common and integrally formed to each other. The inner pipe has the side walls extending from a common part of the outer pipe and the inner pipe to the diametral direction of the outer pipe in parallel and the recess wall facing the common part of the outer pipe and the inner pipe at a deep end of the side walls is not expanded more than the space between the side walls.

主权项

1. A double pipe in which an inner pipe is arranged inside an outer pipe
a portion of the outer pipe and a portion of the inner pipe partially made common and integrally formed with each other, the inner pipe having parallel side walls spaced apart a selected distance from one another and extending from the common part of the outer pipe and the inner pipe in a diametral direction of the outer pipe, and a recess wall at an interior end of the side walls, the recess wall facing the common part of the outer pipe and the inner pipe, the recess wall not expanded more than the distance between the parallel side walls.