Construction machine including hydraulic pump

摘要

Provided is a construction machine including an engine, a hydraulic pump with a supercharger, and a hydraulic actuator, being capable of attaining both of a quick rise of engine speed and an operation of the hydraulic actuator during the rise of the engine speed. The construction machine further includes a supercharging pressure detector to detect a supercharging pressure of the supercharger and a controller to control absorption torque of the hydraulic pump, namely, pump torque. Until engine speed of the engine reaches target engine speed, the controller calculates target pump torque from a predetermined relationship between engine no-load speed and the target pump torque, corrects the target pump torque so as to make it smaller as the detected supercharging pressure is lower, and limits actual pump torque to the corrected target pump torque, until engine speed reaches target engine speed from engine speed lower than the target engine speed.

主权项

1. A construction machine comprising:
an engine with a supercharger; a variable-displacement hydraulic pump driven by the engine; a hydraulic actuator driven by hydraulic fluid discharged from the hydraulic pump; a supercharging pressure detector adapted to detect a supercharging pressure of the supercharger; and a controller adapted to control pump torque, which is absorption torque of the hydraulic pump, the controller being adapted to perform, until engine speed of the engine has risen to reach a target engine speed from engine speed lower than the target engine speed, calculating target pump torque from a predetermined relationship between engine no-load speed set and the target pump torque, correcting the target pump torque so as to make the target pump torque be smaller as the supercharging pressure is lower, on the basis of the supercharging pressure detected by the supercharging pressure detector, and limiting actual pump torque to the corrected target pump torque.