Control Device and Working Machine

摘要

A control device for suppressing engine load fluctuation according to main pump circuit conditions, wherein an assist torque calculation task includes a target engine torque calculation task separating smooth torque components from main pump load torque and setting a minimum value of either smooth torque component or engine setting torque as target engine torque, and a subtractor calculating target assist torque based on a difference between the main pump load torque and the target engine torque, the assist torque calculation task controlling a capacity of an assist pump based on the target assist torque and controlling switching between an assist mode and a charge mode.

主权项

1. A control device comprising:
a main pump driven by an engine and supplying hydraulic oil to a hydraulic circuit; a variable capacity assist pump coupled to an engine or a main pump and having both functions of a pump and a motor; an accumulator provided to be capable of communicating with the assist pump, and accumulating hydraulic energy; accelerator means for inputting engine setting torque; engine actual torque acquiring means for detecting or calculating engine actual torque; engine control means for controlling the engine actual torque; and assist pump control means for controlling a capacity of the assist pump and switching between an assist mode for assisting the engine with the motor function of the assist pump and a charge mode for accumulating pressure in the accumulator with the pump function of the assist pump, wherein the assist pump control means includes:
main pump load torque calculating means for calculating main pump load torque applied to the main pump;engine target torque calculating means for separating a smooth torque component from the main pump load torque and setting, as engine target torque, a minimum of the smooth torque component and the engine setting torque;assist target torque calculating means for calculating assist target torque from a difference between the main pump load torque and the engine target torque; anda function for controlling the capacity of the assist pump and controlling the switching of the assist mode and the charge mode on the basis of the assist target torque.