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. 18, 1994
Filed:
Dec. 01, 1993
Masayoshi Yamanaka, Wako, JP;
Hiroshi Maruyama, Wako, JP;
Takeshi Suzuki, Wako, JP;
Kazutomo Sawamura, Wako, JP;
Shigetaka Kuroda, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An evaporative fuel-processing system for an internal combustion engine includes an evaporative emission control system having a canister, a first passage connecting between the canister and a fuel tank, a second passage connecting between the canister and the intake system of the engine, and a purge control valve arranged across the second passage, a drain shut valve for opening and closing an inlet port of the canister, and pressure sensors for detecting pressure within the evaporative emission control system. The evaporative emission control system is negatively pressurized by introducing negative pressure from the intake system into the evaporative emission control system by opening the purge control valve and closing the drain shut valve, to thereby bring the evaporative emission control system into a predetermined negatively pressurized state, and then closing the purge control valve to complete the negative pressurization. Presence/absence of a leak from the system is detected based on a rate of decrease in negative pressure within the evaporative emission control system after the closing of the purge control valve. The leak detection is started when the pressure within the evaporative emission control system becomes substantially equal throughout the system after the completion of the negative pressurization.