Patent ID: 6671942
Filing Date: 2004-01-06
Classification: G01N,Y10S,Y10T

Abstract:
A method for manufacturing a gas sensor having a tubular housing and a sensing element disposed in said housing, comprising:a step of inserting said sensing element into said tubular housing from a rear end toward a front end of said housing, said sensing element having a flange portion protruding radially outward from an outer surface thereof, and said housing having an inner cylindrical stepped portion protruding radially inward from an inner cylindrical surface thereof; a step of placing said flange portion of said sensing element on said inner cylindrical stepped portion of said housing; a step of inserting a hardened powder ring into an annular end space defined between the inner cylindrical surface of said housing and the outer surface of said sensing element, said hardened powder ring being a hardened block of inorganic powder configured into a ring shape; a step of pressing said hardened powder ring toward the front end of said housing by a tubular pushing member and crushing said hardened powder ring into inorganic powder by said tubular pushing member so that said annular end space is stuffed by the inorganic powder; wherein the following relationship is satisfied 0.275 mm&lE;rpâˆ’Re&lE;0.375 mm, and0.15 mm&lE;rhâˆ’Rp&lE;0.25 mm, where rp represents an inner radius of said pushing member, Rp represents an outer radius of said pushing member, rh represents an inner radius of said housing, and R&thgr; represents an outer radius of said sensing element at a portion substantially defining said annular end space.