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. 20, 2004
Filed:
Sep. 05, 2002
Kenji Nagasaki, Nagoya, JP;
Masao Kano, Gamagoori, JP;
Yasuo Kato, Aichi-ken, JP;
Hideki Miyahara, Aichi-ken, JP;
Tokiji Ito, Toyota, JP;
Other;
Abstract
When detection of an abnormality in a fuel vapor treating system is executed, a vapor zone including a fuel tank and a canister is sealed. The sealed vapor zone is pressurized. Whether fuel vapor is leaking from the vapor zone is determined based on the pressure in the sealed vapor zone. A canister valve selectively connects a canister with and disconnects the canister from the atmosphere. During the abnormality detecting procedure, an electronic control unit (ECU) shuts the canister valve. After the abnormality detecting procedure is ended, the ECU sends a control signal having a predetermined frequency to the canister valve, thereby gradually increasing the opening size of the canister valve. Accordingly, the pressure in the vapor zone is gradually lowered to the atmospheric pressure. This prevents fuel vapor adsorbed by the canister from being released to the atmosphere.