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:
Feb. 25, 2020
Filed:
May. 07, 2019
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Yoshinori Hibino, Nagoya, JP;
Kentaro Mori, Nagoya, JP;
NGK SPARK PLUG CO., LTD., Aichi, JP;
Abstract
A purification control device () controls a urea water injector () for supplying urea as a reducing agent to an SCR catalyst (). The purification control device () sets a pre-deterioration maximum occlusion amount based on the SCR catalyst temperature, and estimates the concentration of ammonia discharged from the SCR catalyst (), as an estimated ammonia concentration, based on upstream NOx concentration information, downstream NOx concentration information, urea injection amount information, the pre-deterioration maximum occlusion amount, and ammonia occlusion amount information. The purification control device () acquires downstream ammonia concentration information. When the downstream ammonia concentration is greater than the estimated ammonia concentration, the purification control device () decreases the supply amount of urea from the urea water injector ().