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. 13, 1993
Filed:
Jun. 16, 1992
Shinji Kojima, Himeji, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An EGR control device for an engine comprising: an exhaust gas recirculating passage for connecting an exhaust pipe to an intake pipe of an internal combustion engine; an exhaust gas recirculating valve provided at the exhaust gas recirculating passage for controlling a quantity of exhaust gas which is recirculated to intake air of an engine; an oxygen sensor provided at an intake passage on the downstream side of a junction point of the recirculated gas and the intake air for detecting an oxygen concentration of the intake air mixed with the recirculated gas; an exhaust gas recirculating valve passage area controlling means for controlling a passage area of the exhaust gas recirculating valve; a running state detecting means for detecting a running state of the engine; a calculating means for calculating a first exhaust gas recirculation ratio based on an output of the oxygen sensor and for calculating a second exhaust gas recirculation ratio corresponding to a value detected by the running state detecting means; and a feedback controlling means for performing a feedback control which increases or decreases the passage area of the exhaust gas recirculation valve so that the first exhaust gas recirculation ratio agrees with the second exhaust gas recirculation ratio.