Title:
EXHAUST EMISSION CONTROL DEVICE FOR ENGINE
Document Type and Number:
Japanese Patent JP2018021497
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To increase an H constituent supplied to an NOx catalyst by executing NOx reduction control for making an air-fuel ratio rich and thus facilitate an increase in the amount of NHto be generated from the NOx catalyst so as to supply the relatively large amount of NHfrom the NOx catalyst to an SCR catalyst.SOLUTION: An exhaust emission control device for an engine includes: an NOx catalyst 45; an SCR catalyst 47; an urea injection valve 51; and NOx reduction control means for setting an air-fuel ratio to a first target air-fuel ratio enabling reduction of NOx occluded in the NOx catalyst and executing NOx reduction control. When a determination that urea injection from the urea injection valve 51 is not being performed normally is made, the NOx reduction control means executes NHsupply NOx reduction control for supplying NHfrom the NOx catalyst 45 to the SCR catalyst 47 by executing air-fuel ratio rich NOx reduction control for making the air-fuel ratio of exhaust gas rich until the air-fuel ratio of the exhaust gas reaches a second target air-fuel ratio richer than the first target air-fuel ratio.SELECTED DRAWING: Figure 12
Inventors:
KANNO MASANOBU
YAMAGUCHI YOSHIMASA
TETSUNO MASAYUKI
YAMAGUCHI YOSHIMASA
TETSUNO MASAYUKI
Application Number:
JP2016152481A
Publication Date:
February 08, 2018
Filing Date:
August 03, 2016
Export Citation:
Assignee:
MAZDA MOTOR
International Classes:
F01N3/08; B01D53/94; F01N3/20; F01N3/24; F01N3/28; F02D41/04; F02D41/38; F02D45/00
Domestic Patent References:
| JP2012127295A | 2012-07-05 | |||
| JP2010112345A | 2010-05-20 | |||
| JP2000265828A | 2000-09-26 | |||
| JP2008506881A | 2008-03-06 |
Foreign References:
| WO2011042997A1 | 2011-04-14 | |||
| WO2015004779A1 | 2015-01-15 | |||
| WO2014115303A1 | 2014-07-31 | |||
| WO2017038194A1 | 2017-03-09 |
Attorney, Agent or Firm:
Takaki Nishijima
Minoru Nakamura
Fumiaki Otsuka
Disciple Maru Ken
Ryo Ishizaki
Minoru Nakamura
Fumiaki Otsuka
Disciple Maru Ken
Ryo Ishizaki