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:
Apr. 11, 1989
Filed:
Oct. 10, 1986
Yoshihisa Kawamura, Yokosuka, JP;
Nissan Motor Company, Limited, Yokohama, JP;
Abstract
An apparatus for monitoring cylinder combustion in an internal combustion engine having at least one cylinder to control the engine by employing a pressure sensor sensitive to combustion pressure in the cylinder for producing a sensor signal indicative of a sensed cylinder combustion pressure level. From the sensor signal, there are extracted a knock signal in a predetermined high frequency range and a cylinder combustion pressure signal in a predetermined low frequency range. The apparatus includes an electrical circuit which provides a first indication in response to an abnormal condition of the high frequency knock signal and a second indication in response to an abnormal condition of the low frequency cylinder combustion pressure signal. The circuit provides a failure indication of the sensor signal being unreliable for use in controlling the engine in the presence of the first and/or second indications. The engine is controlled independently of the sensor signal upon occurrence of the failure indication.