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:
May. 15, 1990
Filed:
Oct. 05, 1988
Wallace R Wade, Farmington Hills, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
An exhaust gas recirculation (EGR) system and construction is provided in which an EGR flow valve and an air flow valve are mounted on a common shaft or, alternatively, interconnected by stepper motors or electric motors to ensure equal response times for the flow of EGR gases and air flow into the engine combustion chamber. In one embodiment, a secondary EGR valve is provided in the EGR passage to bleed the exhaust back pressures to approximately atmospheric level to equal that of the air being inducted past a main air throttle valve. Finally, an EGR control system is provided for calculating the EGR flow rate as to be able to set the spark timing of the engine according to previously determined mapping data that provides values required for best fuel economy at any EGR rate.