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:
Jun. 28, 1988
Filed:
Sep. 28, 1987
Abstract
An air-fuel ratio control system for internal combustion engines has an air-fuel ratio sensor mounted in an exhaust pipe of an internal combustion engine and is adapted to produce an output indicative of the air-fuel ratio of a mixture supplied to the engine, on the basis of the composition of exhaust gases in the exhaust pipe. The air-fuel ratio sensor is provided with an electric heater for heating the air-fuel ratio sensor. The system further has a temperature sensor for sensing the temperature of the internal combustion engine or the ambient air temperature, and an engine operation sensor adapted to sense whether the engine has been stopped, through detection of the state of the ignition switch. When the engine operation sensor has sensed that the internal combustion engine has been stopped while the temperature sensed by the temperature sensor is below a predetermined level, the electric heater is supplied with power for a predetermined time after the stop of the engine so as to evaporate any water content clinging to the air-fuel ratio sensor.