| abstract |
Post injection is stopped when fuel for preventing clogging of a nozzle opening is injected. In an internal combustion engine, a hydrocarbon supply valve (15), an exhaust purification catalyst (13), and a particulate filter (14) are arranged in an engine exhaust passage. When post-injection (PI) is performed to raise the temperature of the exhaust purification catalyst (13) or the particulate filter (14), the hydrocarbon feed valve (15) to the hydrocarbon feed valve (15) nozzle opening When the fuel for preventing clogging is injected, the post injection (PI) injection amount is reduced or the post injection (PI) is stopped. [Selection] Figure 12 |