|
(11) | EP 2 623 738 A8 |
| (12) | CORRECTED EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
|
|
|
|
||||||||||||||||
| (54) | EXHAUST PURIFICATION DEVICE FOR INTERNAL COMBUSTION ENGINE |
| (57) An exhaust purification system of an internal combustion engine provided with an
exhaust purification catalyst which reacts NOX and hydrocarbons. The exhaust purification catalyst includes an upstream side catalyst
and a downstream side catalyst. The upstream side catalyst has an oxidation ability,
while the downstream side catalyst carries precious metal catalyst particles on the
exhaust flow surface and is formed with basic exhaust flow surface parts. The exhaust
purification catalyst can make the concentration of hydrocarbons vibrate by within
a predetermined range of amplitude and by within a predetermined range of period so
as to partially oxidize the hydrocarbons or produce reducing intermediates at the
upstream side catalyst. When the temperature of the upstream side catalyst is less
than a first judgment temperature and the temperature of the downstream side catalyst
is higher than a second judgment temperature, the temperature of the upstream side
catalyst is made to rise.
|