Engine control device for hybrid construction machinery

An engine control device for hybrid construction machinery which includes an engine, an engine auxiliary motor, an energy storage device, a swing motor, and a pump operating an operator, which performs work other than a swing operation, by using driving power of the engine, the engine control device comprising:

• a first target engine rotational speed calculation unit configured to calculate a first target engine rotational speed of the engine based on a dial input value and a work mode input value which are inputted by a driver;
• a second target engine rotational speed calculation unit configured to calculate a second target rotational speed of the engine based on a target power generation amount of the engine auxiliary motor;
• a third target engine rotational speed calculation unit configured to calculate a third target engine rotational speed of the engine based on a torque of the pump;
• and
• an engine speed calculation unit configured to determine one of the first target engine rotational speed, the second target engine rotational speed and the third target engine rotational speed as a final target engine rotational speed;
• and
• wherein the engine speed calculation unit determines the first target engine rotational speed as the final target engine rotational speed when the greater one of the second target engine rotational speed and the third target engine rotational speed is greater than the first target engine rotational speed, and
• the engine speed calculation unit determines the greater one of the second target engine rotational speed and the third target engine rotational speed as the final target engine rotational speed when the greater one of the second target engine rotational speed and the third target engine rotational speed is less than the first target engine rotational speed.