Engine control device and engine control method

An engine control method for controlling an engine with a turbocharger, the method comprising:

• a rotation speed increase mode execution step of executing a rotation speed increase mode which is a mode for increasing a rotation speed of the engine while operating the engine with no load;
• a high-idle mode execution step of executing a high-idle mode for operating the engine with no load, which is different from the rotation speed increase mode, when a first parameter relating to an operation state of the engine reaches a threshold value in the rotation speed increase mode;
• and
• a load application mode execution step of executing a load application mode which is a mode for applying a load to the engine, after the high-idle mode is executed,
• wherein the rotation speed increase mode includes at least one stage of fuel injection in the one combustion cycle of the engine,
• the high-idle mode includes at least two stages of fuel injection in the one combustion cycle of the engine, and
• in the high-idle mode execution step, a timing of second stage fuel injection in the one combustion cycle of the engine in the high-idle mode is retarded, relative to a timing of first stage fuel injection in the one combustion cycle of the engine in the rotation speed increase mode.

An engine control device for controlling an engine with a turbocharger, the device comprising:

• a rotation speed increase mode execution unit configured to execute a rotation speed increase mode which is a mode for increasing a rotation speed of the engine while operating the engine with no load;
• a high-idle mode execution unit configured to execute a high-idle mode for operating the engine with no load, which is different from the rotation speed increase mode, when a first parameter relating to an operation state of the engine reaches a threshold value in the rotation speed increase mode;
• and
• a load application mode execution unit configured to execute a load application mode which is a mode for applying a load to the engine, after the high-idle mode is executed,
• wherein the high-idle mode execution unit is configured to adjust a timing of fuel injection in one combustion cycle of the engine in the high-idle mode so that a second parameter relating to the operation state of the engine falls within a target range.