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:
Mar. 22, 1994
Filed:
Dec. 29, 1992
Takayuki Otsuka, Susono, JP;
Kouichi Osawa, Susono, JP;
Tatsumasa Sugiyama, Kariya, JP;
Katsuhiko Teraoka, Aichi, JP;
Nobuyuki Kobayashi, Toyota, JP;
Koji Okawa, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
A malfunction detecting apparatus for an evaporated fuel purge system includes a first control valve for controlling a flow of fuel vapor in a purge passage between a canister and an intake passage, a second control valve for controlling a flow of air from the atmosphere to the canister via an air inlet opening of the canister, a first control part for turning OFF the second control valve and for turning ON the first control valve during a first time period, so as to subject the purge passage, the canister, and a vapor passage to a negative pressure of the intake passage during the first time period, and a first discriminator for detecting whether or not a malfunction has occurred in the system, in accordance with a pressure change rate derived from pressures of the system sensed at a start of the first time period and at an end thereof. The apparatus further includes a second control part for detecting whether or not a pressure of the system reaches a prescribed negative pressure after it is detected that no malfunction has occurred in the system, and for turning OFF the first and second control valves during a second time period after the prescribed negative pressure is reached, and a second discriminator for detecting whether or not a malfunction has occurred in the system, in accordance with a pressure change rate derived from pressures of the system sensed at a start of the second time period and at an end thereof.