Load sensing system, working machine comprising the system, and method for controlling a hydraulic function

摘要

A load sensing system includes a first assembly of actuators for controlling a first hydraulic function, a pump adapted to supply the actuators with pressurized hydraulic fluid, an electrically controlled valve adapted to control the output pressure of the pump via a hydraulic signal, a first pressure sensor for detecting a load pressure of the first actuator assembly, and a control unit adapted to receive a signal with information about the load pressure detected by the first pressure sensor and to generate a control signal, corresponding to the detected load pressure, to the electrically controlled valve.

主权项

1. Load sensing system comprising
a first assembly of actuators for controlling a first hydraulic function, a pump adapted to supply the actuators with pressurized hydraulic fluid, an electrically controlled valve adapted to control the output pressure of the pump via a hydraulic signal, a first pressure sensor for detecting a load pressure of the first actuator assembly, and a control unit adapted to receive a signal with information about the load pressure detected by the first pressure sensor and to generate a control signal, corresponding to the detected load pressure, to the electrically controlled valve, wherein the control unit is adapted to determine the desired pump pressure so that a differential pressure between the detected load pressure and the pump pressure is varied based upon different operating conditions, wherein the electrically controlled pump control valve is adapted to assume such a position that the hydraulic signal to the pump generates a substantially constant pump pressure when the input signal to the valve from the control unit drops out, and wherein the constant pump pressure constitutes a maximum pressure.