Exhaust gas control apparatus for internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsNobusuke Kabashima, Toshihiro Mori
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Abstract
An exhaust gas control apparatus includes a NOx storage-reduction catalyst, and an injector capable of supplying a reducing agent containing hydrocarbon and carbon monoxide to the NOx storage-reduction catalyst and adjusting a CO ratio that is a ratio of carbon monoxide to hydrocarbon supplied to the NOx storage-reduction catalyst. The exhaust gas control apparatus controls the injector such that the CO ratio becomes lower when the NOx removal treatment is started than when the NOx removal treatment is ended.
Claims7
An exhaust gas control apparatus for an internal combustion engine, the exhaust gas control apparatus comprising:
- a NOx storage-reduction catalyst;
- a reducing agent supplying-and-adjusting device configured to supply a reducing agent containing hydrocarbon and carbon monoxide to the NOx storage-reduction catalyst and adjust a CO ratio that is a ratio of the carbon monoxide to the hydrocarbon supplied to the NOx storage-reduction catalyst;
- and
- an electronic control unit configured to control the reducing agent supplying-and-adjusting device, wherein:
- when a predetermined removal treatment execution condition is satisfied, the electronic control unit is configured to control the reducing agent supplying-and-adjusting device to supply the reducing agent to the NOx storage-reduction catalyst and to perform NOx removal treatment in which NOx stored in the NOx storage-reduction catalyst is removed;
- and
- the electronic control unit is configured to control the reducing agent supplying-and-adjusting device, during the NOx removal treatment, such that the CO ratio becomes lower when the NOx removal treatment is started than when the NOx removal treatment is ended.
Dependencies are inferred from the claim text.