Patent ID: 9145843
Filing Date: 2015-09-29
Classification: F02D,F02P,Y02T

Abstract:
1. A spark-ignition direct injection engine, comprising: an engine body having a cylinder; a fuel injection valve for injecting fuel into the cylinder; a fuel pressure setting mechanism for setting a pressure of the fuel to be injected by the fuel injection valve; an ignition plug arranged to be oriented toward an inside of the cylinder and for igniting mixture gas within the cylinder; and a controller for operating the engine body by controlling at least the fuel injection valve, the fuel pressure setting mechanism, and the ignition plug, wherein when an operating state of the engine body is within a low engine speed range of a predetermined high engine load range, the controller sets the fuel pressure to be a high fuel pressure of 30 MPa or above by the fuel pressure setting mechanism, controls the fuel injection valve to perform the fuel injection at least in a period from a late stage of compression stroke to an early stage of expansion stroke, and controls the ignition plug after the fuel injection completes to perform a spark-ignition of the mixture gas within the cylinder, wherein when the operating state of the engine body is within a high engine speed range of the high engine load range where the engine speed is above the low engine speed range, the controller controls the fuel injection valve to perform the fuel injection at least in a period from intake stroke to a middle stage of the compression stroke, and controls the ignition plug at a predetermined timing to perform the spark-ignition of the mixture gas within the cylinder, and wherein the controller changes the ignition timing of the ignition plug according to an octane number of the fuel, a changing width of the ignition timing according to the octane number is shorter within the low engine speed range of the high engine load range than within the high engine speed range of the high engine load range.