Seal for a sensor element of a gas sensor

US5795454A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl-Hermann Friese · Leonberg, DE
• Helmut Weyl
• Romuald Fries · Rutesheim, DE
• Hans-Martin Wiedenmann · Stuttgart, DE
• Anton Hans · Ludwigsburg, DE

Key dates

• Filing date: Dec 4, 1995
• Grant date: Aug 18, 1998
• Expiry date: Dec 4, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S277/943
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A seal for a sensor element of a gas sensor for determining the oxygen content in gases including exhaust gases of an internal combustion engine, which seal seals the sensor element in a longitudinal bore of a housing, the seal including a sealing stack which is positioned within the longitudinal bore of the housing and around the sensor element in use and which is comprised of two sealing bodies and an additional seal positioned between the two sealing bodies. The two sealing bodies are comprised of a pre-sintered ceramic material. The additional seal is comprised of a pre-pressed powder material and has a porosity which is lower than that of the two sealing bodies. The two sealing bodies and the additional seal are compressed together within the longitudinal bore in use, whereby at least the additional seal is deformed so that the sensor element is sealed in a gap-free manner within the longitudinal bore. The pre-pressed powder material of the additional seal may consist essentially of a ductile metal, which may be one of nickel or copper, or graphite which may be fiber-reinforced.