| 摘要 |
<p>A leveling system for vehicles has one pressure regulating valve for controlling each work cylinder disposed between the vehicle body and a wheel support, the work cylinder having a hydraulically controlled main valve and an electromagnetically controlled pilot valve. To avoid uncontrolled motion of the vehicle body upon start-up, the pilot valve has a valve piston controlled by an electromagnet and acted upon in the valve closing direction by pressure in the control chamber of the main valve, which chamber communicates with a fluid source via a throttle, and in the valve opening direction by the pressure in the work cylinder. The valve piston has a valve seat, cooperating with a fixed valve member. The valve inlet of the pilot valve communicates with the control chamber, and its valve outlet communicates with a fluid tank. The main valve has three valve positions. One valve connection for the work cylinder is blocked or selectively communicates with the other valve connections for the fluid source and the fluid tank, respectively. A blockable valve device precedes the valve connection for the fluid tank. Both the fluid source and the fluid tank are assigned one further valve device each.</p> |
