| 摘要 |
PURPOSE:To prevent the abrupt operation of a hydraulic cylinder in advance caused by its load by a method wherein a relation of actual value signal fed from a load sensor is continuously monitered and an electrical output signal is generated when the actual value is decreased by a value lower than the stored value. CONSTITUTION:When an operating device is stopped while a load F is carried by it, a memory instruction signal input unit 18 is operated to feed a memory instruction signal into an input port 21, resulting in that subsequently a calculater 17 moniters continuously the memorized value and an actual value from a load sensor 16 fed to the input port 21 through A/D converter 19 and then if the actual value is decreased by a value more than the specified value in respect to the memorized value, an electrical signal is outputted from its output port 25. An electrical output signal from the calculation unit 17 closes a relay switch 27, opens a solenoid valve 28 and then a hydraulic oil is supplied to an operating oil chamber 5 for carrying the load in the hydraulic cylinder 1. |
