KNOCK PREVENTING METHOD FOR ENGINE UTILIZING TWO KINDS OF FUEL

PURPOSE:To prevent knock over the whole operating range, by sucking the mixture of gasoline and air, and by injecting light oil into a combustion chamber in the vicinity of the top dead center during compression stroke. CONSTITUTION:During suction stroke of a high compression ratio engine 1, gasoline from a fuel supply device in an intake-air pipe 3 is atomized and then fed, and the thus obtained mixture is charged into a combustion chamber, and then light oil is injected into the combustion chamber in the vicinity of the top dead center during compression stroke to autogenously ignite the mixture and oil. Further, by adjusting the supply ratio between gasoline and light oil in accordance with the operating condition of the engine, it is possible prevent knock in low, middle and high load ranges.