Patent ID: 7534332
Filing Date: 2009-05-19
Classification: G01N,Y10T

Abstract:
1. A process for manufacturing a gas sensor, the gas sensor including: a gas detecting element extending in an axial direction of said gas sensor in which a leading end side of said gas detecting element is to be exposed to a gas to be measured; a cylindrical metal shell housing said gas detecting element such that said gas detecting element protrudes from a leading end side of said metal shell; a cylindrical protector covering an outer circumference of a leading end portion of said metal shell and covering said leading end side of said gas detecting element; a fitting portion which comprises a portion of said leading end portion of said metal shell and a portion of said protector fitted on each other; a space-forming portion which comprises a portion of said leading end portion of said metal shell and a portion of said protector overlapping each other through an annular space; and a weld portion welding said protector to said metal shell through said annular space, wherein the annular space has a width in a radial direction of 0.03 mm or more, the process comprising: applying a lubricant to an outer circumference of said leading end portion of said metal shell; assembling said metal shell having said lubricant applied thereto and said protector, so that a fitting portion, in which said leading end portion of said metal shell and said protector fit on each other, and a space-forming portion, in which said leading end portion of said metal shell and said protector overlap each other through an annular space, are formed along said axial direction; and welding said metal shell and said protector by forming a welded portion extending from an outer circumference of said protector through said annular space.