| 摘要 |
<p> An electrohydraulic conversion valve (3a) such as a cylinder controlling control valve (3) is connected to the output side of a controller (23) for performing a control computing based on an operation electric signal from an electric joystick (12a) or the like. A control valve return pressure (PT) and a load sensing pressure (PL) are detected by first and second pressure detectors (18), (19) and the start of a hydraulic cylinder (7) is detected by a rise of the pressure difference (ΔP) between these pressures. The controller (23) is provided with a function generator (14a) having a standard function (F) for setting the relation between an operation electric signal and an instruction value to the electrohydraulic conversion valve (3a) and the like and with a calibration computing unit (20) for modifying the standard function (F). The calibration computing unit (20) computes a deviation (ΔS) between an instruction value set by the standard function (F) at the start of the cylinder and an instruction value stored at the actual start of the cylinder and adds the deviation to the standard function (F).</p> |
