Patent ID: 9695770
Date: 2017-07-04
CPC Classifications: F02D,F02P,Y02T

Claim:
1. A control device of a spark-ignition engine, comprising: a main body of the engine having a cylinder; a fuel injection valve for injecting fuel supplied into the cylinder; an ignition plug for igniting mixture gas within the cylinder; and a controller for operating the engine by controlling at least the fuel injection valve and the ignition plug, wherein according to an operating state of the engine, the controller switches an ignition mode between a compression-ignition mode in which compression-ignition combustion is performed by causing the mixture gas to self-ignite and combust, and a spark-ignition mode in which spark-ignition combustion is performed by igniting the mixture gas with the ignition plug to combust the mixture gas; wherein the controller switches the ignition mode from the spark-ignition mode to the compression-ignition mode by performing a transition mode in which compression-ignition combustion is performed to forcibly decrease a temperature inside the cylinder; and wherein the controller decreases the temperature inside the cylinder and performs the compression-ignition combustion by injecting the fuel with the fuel injection valve from an intake stroke to an early stage of compression stroke in the compression-ignition mode, and at least after a middle stage of the compression stroke in the transition mode.