Coupling structure of coupling and manhole for the inside sub- tube and coupling for manhole internal corresponding closed die forging sub- tube

摘要

PPROBLEM TO BE SOLVED: To use an inner auxiliary pipe joint in common for plural kinds of upstream side main pipes regardless of a difference in a diameter and a construction material of the upstream side main pipes without damaging the inner auxiliary pipe joint and an inner auxiliary pipe by earthquake motion. PSOLUTION: An outlet side end part 12a of the upstream side main pipes 12 is connected to a manhole side wall 16a via a flexible joint 28, and the inner auxiliary pipe joint 18 is installed on an inside surface of the manhole side wall 16a. An inflow port 38a of the inner auxiliary pipe joint 18 is formed in the size of slipping out to the outside by separating annular clearance 48 from the outlet side end part 12a of the upstream side main pipes 12. Thus, when vibration and force are applied to the upstream side main pipes 12 and a manhole 16 by the earthquake motion, since relative displacement of the upstream side main pipes 12 and the manhole 16 is absorbed by the flexible joint 28, the relative displacement can be prevented from being transmitted to the inner auxiliary pipe joint 18 and the inner auxiliary pipe 20. PCOPYRIGHT: (C)2004,JPO