Denso Corporation

Nippondenso Co., Ltd.

Hiroshi Sugino

Namitsugu Fujii

Hiromi Sano

Yasumichi Hotta

Masatoshi Suzuki

Hirokazu Yamada

Masahiro Shibata

Syuichi Nakano

Masato Ozawa

Tooru Katafuchi

Tadashi Tsuruta

A gas sensor element is inserted into a housing having a base end and is fixed with respect to the housing. Terminal electrodes are provided on the base end of the sensor element. An atmosphere-side cover including an insulator with terminal accommodation holes is provided on the base end of the housing. The insulator also has an element accommodation hole (communicating with the terminal accommodation holes) in which the base end of the sensor element is placed. The insulator has ribs forming inner surfaces defining the element accommodation hole. The rib thickness is smaller than that of the sensor element base end. Metal terminals are at least partially placed in respective terminal accommodation holes and have connecting portions with leads for external electrical connection. The ribs are located between the metal terminals to form spaces between the metal terminals. As the sensor element base end is placed in the element accommodation hole, terminal electrodes on the base end come into contact with the metal terminals and thereby electrically connected with the leads.

Gas sensor having pre-stressed terminal for contact with inserted sensor element

An oxygen sensor element is provided which may be used in an oxygen sensor designed to measure the concentration of oxygen contained in exhaust gasses of an automotive internal combustion engine. The gas sensor element includes a solid electrolyte body, a target gas electrode, a reference gas electrode, and a catalytic layer formed over the target gas electrode. The catalytic layer is made of heat resisting ceramic grains which hold thereon catalytic metal grains whose average grain size is 0.3 to 2.0 &mgr;m, a weight of catalytic metal grains per unit area of the catalytic layer, as defined by projecting the target gas electrode on a plane, is 10 to 200 &mgr;g/cm . This facilitates the reaction of exhaust gasses such as H , NOx, and HC with O over the target gas electrode, thus resulting in improved accuracy of a sensor output over a wide temperature range.

Oxygen sensor element

An oxygen concentration detector includes a one-end closed cylindrical oxygen sensing element having an inside electrode, outside electrode provided on the inner side and outer side respectively, an electrode protecting layer made up of ceramics porous member provided further outside the outside electrode, and a trap layer 1 of ceramics porous member having a surface roughness of 20 to 100 .mu.m measured according to a 10 point mean roughness measurement and provided outside the electrode protecting layer is employed. By dipping the to-be-detected gas side surface of an oxygen sensing element into a slurry with coarse heat-resisting metal oxide particles, 2 to 50 .mu.m in average grain size, dispersed, depositing the slurry on the surface of a protective layer of an oxygen sensor element, thereafter drying and baking the deposit, a porous poisonous substance trap layer, 10 to 500 .mu.m thick, is formed. The dipping is performed after a previous degassing and strong stirring of said slurry and the stop of stirring.

Oxygen concentration detector

A ceramic heater which can be produced easily, induces no increase of production cost and can restrict the resistance change of a heating body due to migration. According to the present invention, a gap is formed between a ceramic sintered body and a heating body. Thus, migration in which cations are seized within the gap is caused so as to impede the cations from entering into the heating body. This makes it difficult for the cations to migrate and the volume in which the heating body is expanded is secured by the gap 13.

Ceramic heater

Growing community of inventors

Aichi-ken, Japan

Hiroshi Sugino