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:
Oct. 25, 1994
Filed:
Oct. 15, 1993
Hisashi Iida, Aichi, JP;
Yasuo Tagawa, Kariya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
An apparatus for controlling pressures within a fuel tank is provided in a purge pipe connected between the fuel tank and a canister. In an operating condition of an engine, a diaphragm in a control valve provided in a purge pipe between the fuel tank and the canister is moved upward by an intake negative pressure to decrease a set load of a spring, and in a stopped condition of the engine, the diaphragm moves downward to increase the set load of the spring. As a result, in the operating condition of the engine, a valve member is opened when a pressure within the fuel tank exceeds a lower predetermined level. In the stopped condition of the engine, the valve member is opened when a pressure within the fuel tank exceeds a higher predetermined level. Therefore, even when a leakage accident occurs in the operating condition of the engine, evaporated fuel is prevented as much as possible from being discharged in a large amount into the atmosphere. In the stopped condition of the engine, an amount of evaporated fuel produced within the fuel tank can be reduced, so that a canister can be of a compact size.