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(11) | EP 2 891 786 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | EXHAUST PURIFICATION SYSTEM FOR INTERNAL COMBUSTION ENGINE |
| (57) Opportunity for execution of rich control is secured whereby NOx can be removed well. An NOx storage catalyst (14) is arranged in an engine exhaust passage. When it is judged
that rich control execution conditions stand, rich control is executed in order to
release NOx or SOx from the NOx storage catalyst. When it is judged that the rich control execution conditions do
not stand, the gear position where the rich control execution conditions would stand
when assuming the gear position of a transmission (25) were changed under a constant
engine output is found as a target gear position. An indicator (27) is used to display
an indication that the gear position should be changed to the target gear position
to a vehicle operator. When the vehicle operator changes the gear position to the
target gear position and it is thereby judged that the rich control execution conditions
stand, rich control is executed.
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