CONTROLLING SYSTEM OF HYDRAULIC ARCHITECTURAL MACHINERY

A control system for a hydraulic excavator having a prime mover, revolution number control device for the prime mover, at least one variable displacement hydraulic pump driven by the prime mover, displacement volume control device for the pump, actuators driven by pressurized fluid discharged from the pump and working elements driven by the respective actuators. The control system includes maximum revolution number altering device for the prime mover associated with the revolution number control device, maximum displacement volume altering device for the pump associated with the displacement volume control devices, devices for sensing the operation condition of the actuators, devices for selecting an operation mode for each working element and control devices. The maximum revolution number altering device provides at least one maximum revolution number of the prime mover and the maximum displacement volume altering device provides at least one maximum displacement volume so that maximum revolution numbers of the prime mover and maximum displacement volumes are arranged in a plurality of combinations. The plurality of combinations are set in association with the operation condition of the actuators and the selection of the operation mode. The control means selects a combination of the maximum revolution number of the prime mover and the maximum displacement volume of the pumps on basis of output signals of the sensors and selection devices and drives the maximum revolution number altering device and the maximum displacement volume altering device to set the maximum revolution number of the prime mover and the maximum displacement volume of the hydraulic pump.