Patent ID: 7041938
Filing Date: 2006-05-09
Classification: F23Q,Y10T

Abstract:
1. A glow plug comprising: a cylindrical sheath tube closed at its front end and opened at its base end; a cylindrical metal shell covering the side of said base end of said sheath tube with the side of said front end projecting therefrom; a coil including a front end portion and a base end portion, arranged in said sheath tube along an axis thereof, and connected at said front end portion to said front end of said sheath tube; a lead member connected with said base end portion of said coil and extending toward the side of said base end of said sheath tube; and insulating powder packed in said sheath tube, wherein a front end side portion of said coil farther than a foremost end of said lead member has a coil length L not larger than 15 mm in an axial direction from said front end of said sheath tube, a sheath front end portion of said sheath tube enclosing said front end side portion of said coil has an outer diameter not larger than 4.4 mm, wherein a distance from an end point of an axial front end side of a fixed portion where said sheath tube is fixed directly or indirectly through another member on said metal shell, to said foremost end of said lead member, is not smaller than 5 mm toward said axial front end side, and wherein said lead member has a solid rod shape having an outer diameter not smaller than 1.5 mm.