| 摘要 |
A directional-control valve is typically comprised of a valve spool that slides linearly within a valve body. The valve body typically includes five internal ports, which are covered or exposed as the spool slides within the body. The typical five-internal-port architecture precludes certain combinations of port connectivity when the spool is in the center position. For example, when the spool is in the center position, providing connectivity between the actuator ports, while simultaneously providing fluid isolation of the supply and exhaust ports, is not directly achievable with a standard five-port architecture. This application describes three embodiments that enable the aforementioned port connectivity when the spool is in the center position. |
| 主权项 |
1. A directional-control valve comprising a valve spool within a valve body, wherein:
the valve spool is configured to move within the valve body between a first position, a second position and a third position; the third valve spool position lies between the first and the second valve spool positions; and wherein the valve body comprises:
five external ports arranged between a first end of the valve body and a second end of the valve body, comprising a first exhaust port, a first actuator port, an inlet port, a second actuator port, and a second exhaust port; andseven internal ports arranged between a first end of the valve body and a second end of the valve body, wherein the seven internal ports are in fluid communication with the five external ports in the following order along the valve body: the first exhaust port, the first actuator port, the inlet port, the second actuator port, the second exhaust port, the second actuator port and the first actuator port. |
