| 摘要 |
PURPOSE: An automatic horizontality control apparatus is provided to rapidly and precisely control a hydraulic cylinder because a large flow rate control valve is used for long distance expansion and a small flow rate control valve is used for short distance expansion. CONSTITUTION: An automatic horizontality control apparatus comprises a horizontal positioning sensor(10), a hydraulic generating device, expansion units(30), and a control part. The horizontal positioning sensor measures angles inclining objects. Each expansion unit comprises a hydraulic cylinder, a passage, a displacement sensor, a large flow rate control valve, and a small flow rate control valve. The hydraulic cylinder flexibly expands with the hydraulic pressure of the hydraulic generating device. The displacement sensor measures the expansion length of the hydraulic cylinder. The large flow rate control valve is installed in a first passage to open and close the first passage in order to flexibly expand the hydraulic cylinder with the hydraulic pressure generating in the hydraulic generating device. The small flow rate control valve is installed in a second passage to open and closes the second passage in order to flexibly expand the hydraulic cylinder with the hydraulic pressure generating in the hydraulic generating device. |
