Engine control device

An engine control device comprising:

• a required torque acquiring part that acquires a required torque for an engine having a plurality of cylinders connected to an exhaust pipe which is provided with a catalyst for purifying exhaust gas when a temperature of the catalyst reaches an activation temperature;
• a compression release cylinder selecting part that selects, from the plurality of cylinders, one or more compression release cylinders for opening an exhaust valve without causing fuel to be injected during a compression process, depending on magnitude of the required torque;
• an exhaust valve control part that opens an exhaust valve of the compression release cylinder during a compression process of the compression release cylinder;
• a fuel injection amount determining part that determines an amount of fuel to be injected into an operating cylinder, which is a cylinder other than the compression release cylinder among the plurality of cylinders, where fuel is caused to be injected, according to a load torque generated by opening the exhaust valve and the required torque;
• and
• an injection control part that controls a fuel injector that injects fuel into each cylinder to inject fuel, according to the amount of fuel injection determined by the fuel injection amount determining part, into the operating cylinder.