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:
Sep. 14, 1999
Filed:
Dec. 01, 1997
Yukio Yoshioka, Toyota, JP;
Zenichiro Mashiki, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A method and an apparatus for generating vacuum pressure in an engine is disclosed. The engine includes an intake path, combustion chambers and an exhaust path. Airflow in the intake path is controlled by a throttle valve. An exhaust gas recirculation (EGR) passage deflects a part of flow of the exhaust gas to the intake path from the exhaust path. An EGR valve regulates the flow of exhaust gas passing through the EGR passage. A brake booster is connected to the intake path and increases braking force of the vehicle. A pressure sensor detects the pressure in the booster. A central processing unit determines whether the detected pressure is higher than a predetermined value. The throttle valve is in a relatively open position when the engine performs stratified charge combustion. The throttle valve decreases the pressure in the intake path when the throttle valve restricts flow. The CPU controls the throttle valve to decrease the pressure in the intake path when the booster pressure is higher than the predetermined value and actuates the EGR valve to decrease the gas flow in the EGR passage. This results in better brake and engine performance.