Engine control device

An engine control device that controls an engine in which, as flow paths for an engine coolant that returns from an outlet of a water jacket to an inlet of the water jacket, a radiator water passage provided through a radiator, a temperature raising water passage provided with a temperature raising heat exchanger for raising a temperature of another fluid with heat of the engine coolant, and a bypass water passage through which the engine coolant flows while the engine coolant bypasses the radiator and the temperature raising heat exchanger are provided in parallel, and a thermostat configured to open and close the radiator water passage and a switching valve configured to switch between a state in which flow of the engine coolant from the temperature raising water passage into the water jacket is not allowed and a state in which the flow of the engine coolant from the temperature raising water passage into the water jacket is allowed are provided in a cooling system, the engine control device comprising:

• a calculation processing device;
• and
• a storage device, wherein:
• the storage device is configured to store a normal time map and a transition time map as maps that use, as input, an outlet water temperature that is a temperature of the engine coolant flowing out of the water jacket and output a value that is used for calculating an engine operation amount;
• the calculation processing device is configured to calculate, during a transition period that is a period until a difference between a temperature of the engine coolant flowing out of the temperature raising heat exchanger and the outlet water temperature decreases below a predetermined value after the switching valve switches from the state in which the flow of the engine coolant from the temperature raising water passage into the water jacket is not allowed to the state in which the flow of the engine coolant from the temperature raising water passage into the water jacket is allowed, the engine operation amount using the transition time map, and calculate, during a period other than the transition period, the engine operation amount using the normal time map;
• and
• the normal time map and the transition time map are configured such that the outlet water temperature when the normal time map and the transition time map output the same value is lower on the transition time map than on the normal time map.