Patent ID: 8231143
Filing Date: 2012-07-31
Classification: B60H,F16L

Abstract:
1. A double pipe connection structure, comprising: a double pipe including an inner pipe, an outer pipe and a supporting rib, the inner pipe and the outer pipe being coaxially arranged and the supporting rib being integrally formed in the double pipe in an axial direction, such that the supporting rib connects the inner pipe to the outer pipe; an inner pipe side O-ring; an outer pipe side O-ring; and a joint member including: wherein a pressure in the first-pressure connecting hole is lower than a pressure in the second-pressure connecting hole, wherein the first hole and the second hole are bored within the joint member so as to be aligned in the axial direction, wherein an end of the inner pipe extends beyond a corresponding end of the outer pipe and the end of the inner pipe is hermetically sealed in the second hole by the inner pipe side O-ring disposed between an inner periphery of the second hole and an outer periphery of the inner pipe, wherein the corresponding end of the outer pipe includes an end portion having an outer pipe expanded part, the outer pipe expanded part of the outer pipe having an outer diameter that is larger than an outer diameter of a portion of the outer pipe adjacent to the end portion of the outer pipe, wherein the outer pipe expanded part of the outer pipe is hermetically sealed in the first hole by the outer pipe side O-ring disposed between an inner periphery of the first hole and an outer periphery of the outer pipe, wherein the supporting rib of the double pipe is detached from the outer pipe at the outer pipe expanded part of the outer pipe and the supporting rib remains connected to the inner pipe at the outer pipe expanded part of the outer pipe, wherein the outer pipe expanded part of the outer pipe includes a bead part projecting from the outer pipe expanded part in a radial direction, wherein the joint member includes a stepped part with which the bead part engages as the outer pipe expanded part of the outer pipe is inserted into the first hole, so as to control an amount of insertion of the outer pipe expanded part into the first hole, and wherein the joint member includes a collar part which is caulked onto the bead part of the outer pipe expanded part, such that the collar part combines the outer pipe with the joint member.