| 摘要 |
PURPOSE:To prevent accidental fire at the sparking plug in such a way that an expansion chamber which is capable of receiving heat is installed at the backside of a fuel suction valve to feed high pressure gaseous fuel, and cooling due to adiabatic expansion of the gaseous fuel is eliminated. CONSTITUTION:An air intake valve 22, a fuel suction valve 24 and an exhaust valve 26 are provided on a cylinder head 16. And an expansion chamber 46a having an enlarged volume is formed at the end of a fuel path 46 situated at the back of the fuel suction valve 24 located in the cylinder head 16. High pressure gaseous fuel which is fed from a gaseous fuel tank 51 through fuel path 46 arrives at the expansion chamber 46a, at the time of low load, such as during idling, flow velocity of fuel exceeds sound velocity, it makes adiabatic expansion, and its temperature is lowered, but this temperature drop is eliminated by heat which is received from the inner wall surface of the cylinder head 16. |
