The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 06, 2001
Filed:
Jan. 25, 1999
Akio Mizutani, Nagoya, JP;
Teppei Okawa, Kounan, JP;
Hiroshi Kubota, Wako, JP;
Seiichi Hosogai, Wako, JP;
Hiroyuki Fujita, Wako, JP;
NGK Spark Plug Co., Ltd., Tokyo, JP;
Abstract
An oxygen sensor is disposed behind an exhaust gas purifying catalyst for an internal combustion engine and which suppresses the influence of unburnt hydrocarbon on the output voltage. A sensor element,is provided with a detection electrode,on the outer face of a zirconia ceramic body,, a reference electrode,on the inner face of the ceramic body,and a spinel protective layer,on the outer surface of the detection electrode,. The tip end of the sensor element,is covered with a protective cover,which is provided with an outer partition wall,having through holes,and an inner partition wall,having through holes,. In a case where the pressure difference between the inside and outside of the protective cover,is &Dgr;P(atm) when the atmospheric air with a volume flow rate Q(L/min) is passed into the protective cover,from the outside, the ratio &Dgr;P/Q,is 3.2×10,(atm·min,·L,). When the surface temperature of the sensor element,is changed in a range of sensor active temperature, the reversing time is substantially constant. Therefore, the catalyst deterioration can be detected by the oxygen sensor with high accuracy.