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:
Dec. 13, 2011
Filed:
Apr. 09, 2008
Shinichiro Kawakita, Oobu, JP;
Keiji Ohshima, Gamagoori, JP;
Yoshiaki Nishijima, Toyokawa, JP;
Nippon Soken, Inc., Nishio, JP;
Denso Corporation, Kariya, JP;
Abstract
An exhaust emission control device has an additive valve and a control unit to decrease nitrogen oxides contained in an exhaust gas by means of a reducing agent. The control unit sets a valve opening period of time and a valve closing period of time alternately elapsing in a repetition cycle. The control unit controls the valve to discharge the agent into the exhaust gas during each valve opening period and to stop discharging the agent during each valve closing period. The control unit sets the valve opening period to be shortened as a flow rate of the exhaust gas is lowered, so that a penetration force of the reducing agent is appropriately set. The control unit sets the repetition cycle at a value depending on the flow rate of the nitrogen oxides to sufficiently deoxidize the nitrogen oxides by means of the agent.