Exhaust purification system

Patent metadata

Field	Value
Publication number	US-10337433-B2
Application number	US-201515510660-A
Country	US
Kind code	B2
Filing date	Sep 11, 2015
Priority date	Sep 12, 2014
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

An exhaust purification system includes: an NOx reduction type catalyst, which is provided in an exhaust passage; an intake air amount sensor, which detects an intake air amount of the internal combustion engine; and a controller, which executes a regeneration treatment that recovers an NOx purification capacity of the NOx reduction type catalyst by switching an exhaust air fuel ratio from a lean state to a rich state by using: an air-system control to reduce the intake air amount; and an injection-system control to increase a fuel injection amount, wherein, in response to a detection value of the intake air amount sensor, the controller changes at least one of a fuel injection timing and the fuel injection amount in the internal combustion engine, in at least one period of switching of: a period of starting the regeneration treatment; and a period of ending the regeneration treatment.

First claim

The invention claimed is:

1. An exhaust purification system comprising:
an NOx reduction type catalyst, which is provided in an exhaust passage of an internal combustion engine, reduces and purifies NOx in an exhaust gas;
an intake air amount sensor, which detects an intake air amount of the internal combustion engine; and
a controller, which executes a regeneration treatment that recovers an NOx purification capacity of the NOx reduction type catalyst by switching an exhaust air fuel ratio from a lean state to a rich state by using:
an air-system control to reduce the intake air amount; and an injection-system control to increase a fuel injection amount, which are used in combination,
wherein, in response to a detection value of the intake air amount sensor, the controller executes a control to change at least one of a fuel injection timing and the fuel injection amount in the internal combustion engine, in at least one period of switching of a period of switching from the lean state to the rich state for starting the regeneration treatment; and a period of switching from the rich state to the lean state for ending the regeneration treatment, and
where the detection value of the intake air amount sensor does not change by a predetermined value or more continuously during a predetermined time, the controller terminates the control to change the at least one of the fuel injection timing and the fuel injection amount in the internal combustion engine.

2. The exhaust purification system according to claim 1 ,
wherein, in the period of switching from the lean state to the rich state for starting the regeneration treatment, the controller: calculates an intake air amount change amount from when the regeneration treatment is started until a current time based on the intake air amount detected by the intake air amount sensor; advances the fuel injection timing of the internal combustion engine in response to the intake air amount change amount; and increases the fuel injection amount of the internal combustion engine in response to the intake air amount change amount.

3. The exhaust purification system according to claim 1 ,
wherein, in the period of switching the rich state to the lean state for ending the regeneration treatment, the controller: calculates an intake air amount change amount from when the regeneration treatment is started until a current time based on the intake air amount detected by the intake air amount sensor; retards the fuel injection timing of the internal combustion engine in response to the intake air amount change amount, and reduces the fuel injection amount of the internal combustion engine in response to the intake air amount change amount.

Assignees

• Isuzu Motors Ltd

Inventors

• Nishito Masaaki
• Nakada Teruo
• Sakamoto Takayuki
• Nagaoka Daiji
• Gabe Masashi

Classifications

• F01N3/0814

  combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts · CPC title

• F02D41/025

  by changing the composition of the exhaust gas, e.g. for exothermic reaction on exhaust gas treating apparatus · CPC title

• F02D41/028

  Desulfurisation of NOx traps or adsorbent · CPC title

• F02D41/1454

  the characteristics being an oxygen content or concentration or the air-fuel ratio · CPC title

• F01N3/0842

  Nitrogen oxides · CPC title