| 摘要 |
In an internal combustion engine, a hydrocarbon feed valve (15) arranged in an engine exhaust passage and an electric pump (60) for supplying hydrocarbons to the hydrocarbon feed valve (15) are provided. The injection pressure of the hydrocarbon feed valve (15) is maintained by the electric pump (60) usually at the target injection pressure (PXO). When there is a demand to stop the electric pump (60) during engine operation, the electric pump (60) is stopped. In this way, even when the electric pump (60) is stopped, the amount of hydrocarbons which is required for preventing clogging in the state where the electric pump (60) is stopped is intermittently injected until the injection pressure of the hydrocarbon feed valve (15) falls below a predetermined allowable injection pressure (PXA) which is lower compared with the target injection pressure (PXO). |
