Ceramic conduit assembly with metal outer tube

摘要

A ceramic conduit with a metal outer tube is joined to bonding rings through insert members between end surfaces of the rings and annular bonding surfaces, with the annular bonding surface being not parallel to the axis of the conduit and the insert member being bonded to the ring and conduit. The rings are joined to the outer tube through welds between forward ends of annular protrusions provided in end surfaces which are the reverse surfaces of the surface bonded with the insert members and the forward ends of annular protrusions provided in axial end surfaces of the outer tube. The inner periphery of the outer tube is fitted on the outer periphery of the conduit with a small gap therebetween. The rings are bonded to the conduit with the insert members by being pressed against the conduit in the axial direction of the conduit and only a small quantity of heat is transmitted from the welds to other portions. The outer tube is joined to the rings through portions having a low rigidity to achieve a highly reliable metal and ceramic bonding is achieved and the bonded surfaces are not deteriorated by the welding nor is the outer tube deformed by the welding heat, and an external load is not substantially transmitted to the bonded surfaces.