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. 05, 1998
Filed:
Apr. 24, 1997
Takashi Isobe, Wako, JP;
Takushi Toda, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An evaporative fuel-processing system for an internal combustion engine is comprised of an evaporative emission control system including a canister, a charging passage extending between the canister and the fuel tank, a purging passage extending between the canister and the intake system of the engine, a purge control valve, and a vent shut valve. A pressure sensor detects the pressure within the evaporative emission control system. The interior of the evaporative emission control system is negatively pressurized into a predetermined negatively pressurized state, by opening the purge control valve and closing the vent shut valve. Then, the purge control valve is closed, and leakage from the evaporative emission control system is checked based on the rate of decrease in negative pressure within the evaporative emission control system over a first predetermined time period. An amount of evaporative fuel supplied from the canister to the engine is detected, and when the detected amount of evaporative fuel exceeds a predetermined amount, the abnormality determination of the evaporative emission control system is terminated. The predetermined amount is changed in a direction of mitigating conditions for the abnormality determination over a second predetermined time period after starting of the engine in a cold state.