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. 02, 2012
Filed:
Jan. 17, 2008
Eiichi Kitazawa, Saitama, JP;
Eiichi Kitazawa, Saitama, JP;
Bosch Corporation, Tokyo, JP;
Abstract
Provided is a clogging determining device and a clogging determining method for a reducing agent injection valve, which enable clogging of the reducing agent injection valve to be determined with high precision in further consideration of the individual difference of the system. There are provided an opened-valve pressure reduction amount calculating element for calculating an opened-valve pressure reduction amount representing a pressure reduction amount in the supply passage which is reduced in a predetermined time when the pressure-feeding operation of the pump is stopped under the state that the reducing agent injection valve is set to an injection mode, a closed-valve pressure reduction amount calculating element for calculating a closed-valve pressure reduction amount representing the pressure reduction amount in the supply passage which is reduced in a predetermined time when the pressure-feeding operation of the pump is stopped under the state that the reducing agent injection valve is set to a full-close mode; and a clogging determining element for comparing the opened-valve pressure reduction amount with the closed-valve pressure reduction amount to determine clogging of the reducing agent injection valve.