Patent ID: 6183210
Filing Date: 2001-02-06
Classification: E02F,F04B

Abstract:
A torque control system for a hydraulic pump in a hydraulic construction machine comprising a prime mover, a variable displacement hydraulic pump driven by said prime mover, input means for instructing a target revolution speed of said prime mover, first detecting means for detecting an actual revolution speed of said prime mover, and speed sensing control means between the target revolution speed and the actual revolution speed and controlling a maximum suction torque of said hydraulic pump such that the maximum suction torque decreases as the calculated deviation increases, wherein:said torque control system includes second detecting means for detecting status variables relating to the environment of said prime mover, andtorque modifying means for, in accordance with values detected by said second detecting means, modifying the maximum suction torque of said hydraulic pump to be controlled by said speed sensing control means (70e-70h, 70j, 70k, 32, 22A, 22B) such that the maximum suction torque corresponds to a change in the output power of said prime mover.