| 摘要 |
<p>There is provided an autonomous inverter-driven hydraulic unit in which a command pressure and command flow rate do not need to be inputted from outside and a pressure and flow rate can be autonomously be controlled without requiring any input signal wire. A target horsepower calculation unit 25 of a controller 11 judges which of regions a, b, c a point (present pressure, present flow rate) representing a present operating state belongs to and calculates a target horsepower represented by a point on a target pressure-flow rate characteristic line based on the present pressure and present flow rate. A comparison unit 28 calculates a deviation of this target horsepower and a present horsepower received from a present horsepower calculation unit 26, inputs a control signal representing this deviation to the inverter 3 and controls a rotational number of a variable-speed motor 2 so that the present horsepower coincides with the target horsepower. Thus, autonomous control is performed so that the present pressure and present flow rate are located on the target pressure-flow rate characteristic line. Therefore, no input signal wire is required and surrounding wiring is simplified. <IMAGE></p> |
