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:
Apr. 26, 2005
Filed:
Feb. 27, 2002
Yoichi Iihoshi, Tsuchiura, JP;
Minoru Ohsuga, Hitachinaka, JP;
Yutaka Takaku, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an internal combustion engine diagnosis apparatus comprising a cleanup catalyst arranged on an exhaust pipe of an internal combustion engine and an HC adsorption catalyst arranged downstream of and in parallel to the cleanup catalyst, degradation and failure of the HC adsorption catalyst is accurately diagnosed. The internal combustion engine diagnosis apparatus comprising the cleanup catalyst arranged in the exhaust pipe of the internal combustion engine; and the HC adsorption catalyst arranged in parallel to and downstream of the cleanup catalyst, during high temperature period the HC adsorption catalyst desorbing and cleaning up HC desorbed during low temperature period, wherein degradation of the HC adsorption catalyst is diagnosed based on a gradient of temperature of the HC adsorption catalyst during a period when temperature of the HC adsorption catalyst is within a range of 50° C. to 250° C.