| 摘要 |
PURPOSE:To enable to control the compression ratio of a gas engine in which mixture of gas fuel and combustion air is supplied to a combustion chamber via an intake valve, by controlling the timing for opening and closing the intake valve and an exhaust valve according to the engine load or the calorific value of gas fuel. CONSTITUTION:Mixture gas of gas fuel from a conduit 5 and combustion air from a passage 6 is supplied to a combustion chamber 3 of a gas engine 1 via an intake valve 7, and the mixture gas is ignited and exploded by an ignition plug 40 near the top dead point of the compression stroke of an engine. Valve bodies 22 of the intake valve 7 and an exhaust valve 8 are driven by a double acting cylinder 24, to which pressure oil is supplied from a pump 20 via a solenoid valve 25. In the above arrangement, the solenoid valve 25 is controlled by a signal from a processing circuit 29 to prevent abnormal local temperature rise near the combustion chamber and to thereby prevent knocking of the engine by increasing the overlap period, for instance, at the time of low-load operation of the engine or in case that the calorific value of gas fuel is low. |
