Patent ID: 6550309
Filing Date: 2003-04-22
Classification: G01N

Abstract:
A gas sensor, comprising, in combination:an outer housing; a metallic shell joined to said outer housing, said metallic shell defining a through passageway having an inner surface and an annular cutout extending circumferentially about said through passageway and axially along a portion of said through passageway; a sensor element disposed inside said through passageway of said metallic shell and adapted to detect a component of a measurement gas; a sealing material layer mainly made of glass and disposed between said inner surface of said metallic shell adjacent said annular cutout and an outer surface of said sensor element; a first cushion layer disposed in contact with said inner surface of said metallic shell and an end surface of said sealing material layer located on a front-end side with respect to an axial direction of said sensor element, said first cushion layer being formed of a mixture containing filler particles which are superior in heat resistance to glass contained in said sealing material layer, and binder particles which are superior in heat resistance to glass contained in said sealing material layer and are lower in softening temperature than said filler particles; and a second cushion layer disposed in contact with said inner surface of said metallic shell and an end surface of said sealing material layer located on a rear-end side with respect to the axial direction of said sensor element, said second cushion layer being formed of a mixture containing filler particles and a binder containing glass whose softening temperature is slightly lower than that of the glass contained in said sealing material layer.