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:
Nov. 27, 2001
Filed:
May. 23, 2000
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A hydrocarbon adsorption apparatus is provided in an exhaust passage of an internal combustion engine. The hydrocarbon adsorption apparatus is equipped with a main passage, a switching valve for opening and closing the main passage, and a bypass passage for bypassing the main passage. The switching valve is coupled to a diaphragm of a diaphragm mechanism. A variable chamber in the diaphragm mechanism is connected to an intake manifold through a negative pressure feed line and a vacuum switching valve. When the vacuum switching valve is turned on, a negative pressure is supplied to the variable pressure chamber so that the diaphragm is deflected. In response to the deflection of the diaphragm, the switching valve is closed. The state of the switching valve is judged based on a tendency of changes in pressure of the negative pressure feed line when the vacuum switching valve is turned on.