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. 23, 1997
Filed:
Mar. 18, 1996
Susumu Shinohara, Toyota, JP;
Shinsuke Kiyomiya, Seto, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
In an evaporative emission control system, a canister adsorbs fuel vapor sent from a fuel tank of an engine. The canister is connected to an intake air passage through a purge gas passage and a purge control valve. A control circuit employs a pressure sensor to detect the pressure of the canister when the purge control valve is closed and when the pressure of the canister is stabilized. The control circuit carries out a failure diagnosis based on this pressure. Namely, when the pressure of the canister after it is stabilized deviates from the atmospheric pressure by more than a predetermined reference value, the control circuit determines that the canister has failed, i.e., the canister has a leak. Since the diagnosis can be carried out before starting the engine, the diagnosis can be correctly carried out without affecting the operation of the engine.