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. 09, 1999
Filed:
Oct. 17, 1997
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An oxygen concentration-detecting device detects the concentration of oxygen present in exhaust gases emitted from an internal combustion engine. The device includes an oxygen sensor of a limit current type. A heater heats the oxygen sensor. A first voltage is applied to the oxygen sensor and the concentration of oxygen is detected based on a first output current from the oxygen sensor obtained when the first voltage is applied to the oxygen sensor. A second voltage is applied to the oxygen sensor at a first repetition period and the internal resistance of the oxygen sensor is detected based on a second output current from the oxygen sensor obtained when the second voltage is applied to the oxygen sensor. The oxygen sensor is heated by the heater based on the internal resistance of the oxygen sensor detected. Values of the concentration of oxygen are sampled based on the first output current from the oxygen sensor at a second repetition period shorter than the first repetition period and the sampled values of the concentration of oxygen are stored. The concentration of oxygen is estimated based on the sampled values of the concentration of oxygen stored. In another form of the invention, a predetermined repetition period (first repetition period) at which the second voltage is applied is set in dependence on operating conditions of the engine.