| 摘要 |
An exhaust purification system is provided that can decrease the load acting on a device treating PM, even when switched to stoich operation. The exhaust purification system includes: a PM treatment device, a three-way purification catalyst, an LAF sensor, and an ECU (3) that performs feedback control so that an LAF sensor output (Vex) becomes a target value (Vop) determined so that the three-way purification reaction is optimized during stoich operation. The ECU (3) includes a fuel controller (32) that determines a fuel injection amount (Gfuel) so that a state in which an air/fuel ratio of the air/fuel mixture is leaner than stoich and a state richer than stoich are alternately realized by modulating a fuel correction amount (dGfuel) determined so as to cause the LAF sensor output (Vex) to converge to the target value (Vop) by employing a predetermined modulation algorithm. |
