Control device for compression self-ignition engine

A control device for a compression self-ignition engine including a cylinder, a piston fitted in the cylinder and having a concave cavity formed in a crown surface thereof, and an intake valve configured to open and close an intake port configured to introduce intake air into a combustion chamber defined by the cylinder and the piston, the engine being configured to execute compression self-ignition (CI) combustion in which a mixture gas of fuel and air combusts inside the combustion chamber by self-ignition, the control device comprising:

• a fuel injection system configured to inject fuel from a ceiling surface of the combustion chamber into the combustion chamber;
• and
• an injection controller configured to cause the fuel injection system to carry out a first injection to inject fuel at a first timing in a compression stroke, and a second injection to inject fuel at a second timing later than the first timing in the compression stroke, while executing the CI combustion,
• wherein the first timing is set at a timing when the fuel injected from the fuel injection system goes toward a part radially outward of the cavity, and the second timing is set at a timing when the fuel injected from the fuel injection system goes toward the cavity,
• wherein, while the engine is operated by the CI combustion under a given first condition, the injection controller causes the fuel injection system to carry out the first injection and suspend the second injection, and
• wherein, while the engine is operated by the CI combustion under a second condition in which a temperature inside the combustion chamber at a close timing of the intake valve becomes lower than the temperature under the first condition, the injection controller causes the fuel injection system to carry out at least the second injection.