Ford Motor Company Limited

Michael J Esper

Stanley R Merchant

Wells L Green

Russell J Haeberle

Tseng-Ying Tien

Charles M Wells

Henry L Stadler

Donald J Romine

Brian G Winegar

A planar magnetic transducer uses thin film technology to form a coil on a ceramic substrate. A relatively powerful magnet is positioned adjacent the substrate so a changing magnetic reluctance adjacent to the coil can be detected by a voltage change at the coil.

Planar coil magnetic transducer

An improved sensor having a ceramic element that undergoes a change in an electrical characteristic in response to a change in the partial pressure of oxygen in a mixture of gases to which the ceramic element is exposed. Sensors of this type are used to detect the air/fuel ratio of mixtures supplied to internal combustion engines. Prior art sensors are characterized by little change in their respective electrical characteristics at low operating temperatures. A charge transfer material, platinum or platinum/rhodium is applied to the ceramic element to facilitate or make possible the electron transfers required for sensor operation at low temperatures. Platinum/rhodium alloy is the currently preferred charge transfer material. This alloy, which preferably is 90% platinum and 10% rhodium, reduces the minimum temperature of operation for the sensor as taught herein, and it also substantially eliminates vaporization loss of the charge transfer material.

Exhaust gas sensor having porous, metal-impregnated ceramic element

A stoichiometric air/fuel ratio exhaust gas sensor construction particularly useful with variable resistance partial pressure of oxygen responsive sensor material is disclosed. A generally cylindrical mounting body, formed of corrosion resistant material, is arranged for receipt within the exhaust system of an internal combustion engine and is provided with a two-part ceramic insert member for support of a wafer of variable resistance sensor material. The ceramic insert member is comprised of a first portion having a slotted tip for receipt and support of the wafer of partial pressure of oxygen responsive ceramic sensor material. The ceramic insert member is arranged to position the wafer within a perforated shield member at a remote free end of the cylindrical housing body. The wafer includes a pair of extending high temperature resistant electrical conductors which are received within bores provided therefor in the ceramic insert member. The extending leads are electrically connected, proximate to the interface of the two-part ceramic insert member, to a pair of relatively flexible, electrically low resistance, high temperature resistant extending lead wires which are received within the second portion of the ceramic insert member.

Stoichiometric air/fuel ratio exhaust gas sensor

A gas sensor, and its method of manufacture, particularly useful as an exhaust gas sensor for an internal combustion engine air/fuel ratio system, is disclosed. The sensor is comprised of a sintered ceramic body of transition metal oxide, such as titania, and includes a pair of spacedapart electrodes. As the partial pressure of oxygen in the gas being sensed varies in response to variations in the inlet air/fuel mixture ratio, the resistance of the ceramic material varies. The active portion of the sensor body is a substantially uniform body of porous ceramic material having a density of less than about 85% of theoretical density and a modulus of rupture in excess of 11,000 psi. The sensor is fabricated from a very pure transition metal oxide powder having a very fine and highly uniform particle size. The transitional metal oxide is selected so that the operating temperature of the resulting device is less than about 75% and preferably less than about 50% of the melting temperature of the metal oxide.

Growing community of inventors

Redford Township, MI, United States of America

Michael J Esper