| 摘要 |
PURPOSE: A system for preventing the pressure overshooting of an electro-hydraulic pump in a hydraulic system is provided to set a limit pressure command into a second pressure command in case of stall, thereby controlling an electronic proportional control valve with selecting one of a first pressure command and the second pressure command as a final pressure command. CONSTITUTION: A system for preventing the pressure overshooting of an electro-hydraulic pump in a hydraulic system includes a flow rate command calculating part (23), a flow rate control part (24), a stall determining part, a flow rate pressure generating part, a gradient limiting part, a selecting part, and a minimum pressure setting part (120). The flow rate command calculating part adds a flow rate command corresponding to a required pressure and subtracts discharge flow rate from the pump in order to calculate a displacement flow rate. The flow rate control part generates a first pressure command corresponding to the displacement flow rate. The stall determining part determines stall based on the first variation rate of the flow rate command and the second variation rate of the discharge flow rate. The flow rate pressure generating part generates a working fluid pressure value corresponding to the discharge flow rate. The gradient limiting part generates a limit pressure command in order to limit the increase gradient of the working fluid pressure value. The selecting part sets the limit pressure command into a second pressure command when the stall determining part determines the stall. The minimum pressure setting part selects one of the first pressure command and the second pressure command as a final pressure command, and then controls an electronic proportional control valve. [Reference numerals] (110) Maximum pressure control part; (AA,FF) Pump discharge flow; (BB) Required pressure; (CC,GG) Flow rate; (DD) Flow rate mapping table; (EE) Pressure command; (HH) System pressure setting |
