| 摘要 |
PROBLEM TO BE SOLVED: To enable arbitrary selection from gas operation and diesel operation, to reduce NOx even in diesel operation, to enable a change and adjustment of a compression ratio according to an operation state in gas operation, and to execute operations having superior combustion efficiency in the whole load area with a rapid start. SOLUTION: This engine is provided with precombustion chamber units 15, each having a precombustion chamber 24a and a solenoid fuel injection valve (liquid fuel injection valve) 14. A compression ratio control valve 13 has an opening/closing control valve B for opening and closing a communication passage A for communicating a main combustion chamber 4 with an intake port. In the gas operation, a valve opening period of the opening/closing control valve B is controlled, according to the operation state, a part of mixture inside the main combustion chamber 4 is let out to control the compression ratio, and fuel gas is ignited and burnt by liquid fuel of a pilot amount from the solenoid fuel injection valves 14. In the diesel operation, the opening/closing control valve B is closed, and the liquid fuel injected from the solenoid fuel injection valves 14 at a high compression ratio is burnt based on a precombustion method. |
