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(11) | EP 2 589 769 A8 |
| (12) | CORRECTED EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
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| (54) | EXHAUST GAS PURIFICATION SYSTEM FOR INTERNAL COMBUSTION ENGINE |
| (57) An exhaust purification system of an internal combustion engine is provided with
an exhaust purification catalyst which removes NOx and a post treatment device. The exhaust purification catalyst has the property of
reducing NOx if making the concentration of hydrocarbons vibrate by within a predetermined range
of amplitude and within a predetermined range of period and furthermore has the function
of oxidizing hydrocarbons. The exhaust purification system feeds hydrocarbons to the
exhaust purification catalyst and raises the temperature of the post treatment device
as temperature elevation control. The exhaust purification catalyst has a high purification
rate range where the NOx purification rate becomes higher than a predetermined rate. In the temperature elevation
control, the total feed amount of hydrocarbons is set and the feed period of hydrocarbons
is set in the high purification rate range in a region at the end at the short side
of feed period of hydrocarbons.
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