Patent ID: 7543448

Claim:
A control system for a hydraulic construction machine comprising: a prime mover; at least one variable displacement hydraulic pump driven by said prime mover; at least one hydraulic actuator driven by a hydraulic fluid from said hydraulic pump; input means for commanding a reference target revolution speed of said prime mover; revolution speed control means for controlling a revolution speed of said prime mover; and operation command means for commanding operation of said hydraulic actuator, wherein said control system comprises: target revolution speed setting means for setting a target revolution speed of said revolution speed control means based on the reference target revolution speed; operation detecting means for detecting a command input from said operation command means; and load pressure detecting means for detecting a load pressure of said hydraulic pump, and wherein said target revolution speed setting means comprises; a first modifying section for changing the target revolution speed depending on the command input from said operation command means, which is detected by said operation detecting means; and a second modifying section for modifying change of the target revolution speed, which is given by said first modifying section, depending on the load pressure detected by said load pressure detecting means.