Patent ID: 6844525
Filing Date: 2005-01-18
Classification: F23Q

Abstract:
1. A glow plug comprising: a tubular, metallic shell having an external-thread portion formed on an outer circumferential surface of the metallic shell so as to allow the glow plug inserted into a plug-mounting hole formed in an engine head to be mounted in the engine head through screwing the external-thread portion into an internal-thread portion formed in the plug-mounting hole; a metallic, tubular member coaxially joined to the metallic shell such that the distal end of the metallic, tubular member protrudes from a distal end of the metallic shell; and a shaft-like heater fixedly provided in the metallic, tubular member such that a distal end of the heater protrudes from a distal end of the metallic, tubular member, the heater including a resistance-heating element embedded in a distal end portion of the heater and adapted to generate heat when electrically energized, wherein the metallic, tubular member comprises an annular protrusion formed on its outer circumferential surface in such a manner as to protrude radially outward and to annularly extend in a circumferential direction; and the metallic, tubular member is joined to the metallic shell while a distal end face of the metallic shell or a distally-facing end face of the metallic shell in the vicinity of the distal end of the metallic shell abuts a rearward-facing end face of the annular protrusion).