Hybrid construction machine

摘要

A hybrid construction machine according to the present invention includes a controller for controlling an engine with a droop characteristic. The controller includes: a target engine output calculation unit (2-4) that calculates a target output of the engine; a target speed setting unit (2-7) that sets a target speed command of a motor-generator; a target droop calculation unit (2-8) that obtains an intersection point of a constant output line with the target output value of the engine and a constant speed line with the target speed command of the motor-generator on a speed-torque characteristic diagram, and determines a governor characteristic of the engine so that the governor characteristic passes through the intersection point; a governor characteristic changing unit (2-10) that changes the governor characteristic of the engine; and a motor-generator control unit (2-9) that controls the motor-generator in accordance with the target speed command value.

主权项

1. A hybrid construction machine comprising:
an engine; a hydraulic pump that is driven by the engine; a hydraulic working portion that is driven by pressure oil discharged from the hydraulic pump; a motor-generator that performs power transfer between the engine and the motor-generator; an electric storage device that supplies electric power to the motor-generator; and a controller that controls the engine with a governor characteristic having a predetermined inclination, the inclination representing a relationship between load and speed such that engine speed decreases with increasing load, the controller including:
a target engine output calculation unit that calculates a target output of the engine;a target speed setting unit that sets a target speed command of the motor-generator;a target droop calculation unit that obtains an intersection point of a constant output line with the target output value of the engine as calculated by the target engine output calculation unit and a constant speed line with the target speed command of the motor-generator on a speed-torque characteristic diagram, and determines a governor characteristic of the engine so that the governor characteristic passes through the intersection point on the speed-torque characteristic diagram;a governor characteristic changing unit that changes the governor characteristic of the engine in accordance with the governor characteristic obtained by the target droop calculation unit; anda motor-generator control unit that controls the motor-generator in accordance with the target speed command value set by the target speed setting unit.