摘要 |
PURPOSE:To realize secure ignition, and further to enable the addition of water necessary for reducing NOx by providing a plurality of water injection passages, and also by providing the communicating places where the respective water injection passages are communicated with an oil passage, in different positions. CONSTITUTION:When the amount of injection is small, only the first injection port of a solenoid valve 31a is opened to inject water into a needle valve sack part 8. When the amount of injection is a little increased, only a solenoid valve 31b is operated. When the amount of injection is further increased, only a solenoid valve 31c is operated. The selection of operation of the respective solenoid valves 31a to 31c and the setting of operating periods are controlled by a computer 34 to an optimum. Thus, secure ignition can be realized, and also the addition of water necessary for reducing NOx can be enabled. |