SEALING DEVICE FOR GAS SENSOR

PCT No. PCT/DE96/02136 Sec. 371 Date Sep. 30, 1997 Sec. 102(e) Date Sep. 30, 1997 PCT Filed Oct. 31, 1996 PCT Pub. No. WO97/28442 PCT Pub. Date Aug. 7, 1997A gas sensor including a sealing arrangement for sensing exhaust gases of internal combustion engines includes a housing for the sealing arrangement having a longitudinal bore; a planar sensor element secured in the longitudinal bore of the housing; a spring element; upper and lower molded parts that are pressed together by means of the spring element; and a sealing material comprised of a ceramic powder and disposed between the upper and lower molded parts and surrounding the sensor element in a gas-tight manner, wherein the lower molded part consists of a disk-shaped base part and a ring that rests on the disk-shaped base part so that an inside space is defined within the ring for holding the ceramic powder, wherein the upper molded part has a ring-shaped, stepped recess which is pressed into the inside space of the lower molded part, and wherein the ceramic powder in the inside space is held in a compressed state due to compressing forces exerted by the spring element. In another embodiment, the gas sensor includes first and second molded parts that are pressed together by means of the spring element; and a sealing material disposed between the first and second molded parts and surrounding the sensor element in a gas tight manner, wherein the first molded part has a cylindrical segment and a conical segment which define an inside space with the planar sensor element, wherein the conical segment has a conically sloped surface, and wherein the sealing material is contained within the inside space, wherein the second molded part has a ring-shaped, stepped recess which is pressed into the inside space along the cylindrical segment, and wherein the conically sloped surface extends at a preselected angle ( alpha ) to the longitudinal axis of the sensor element and at least one of degree of compression and plastic deformation of the sealing material is adjusted by varying the angle ( alpha ).