| 摘要 |
A hydraulic control valve for a construction machine is provided. The hydraulic control valve includes a boom spool slidingly coupled into a valve block to be shifted to control the hydraulic fluid supplied from a first hydraulic pump and a second hydraulic pump to the actuator and provided with an internal path, a supply path of the first hydraulic pump and a supply path of the second hydraulic pump which are formed to be vertically symmetrical about the boom spool, check valves elastically supported to open and close the supply path of the first hydraulic pump and the supply path of the second hydraulic pump, respectively, bridge paths formed to be horizontally and vertically symmetrical with respect to a path formed on a sliding surface of the valve block to supply the hydraulic fluid, cylinder paths supplying the hydraulic fluid from the first hydraulic pump to the actuator. |
| 主权项 |
1. A hydraulic control valve for controlling hydraulic fluid supplied to an actuator in a construction machine, the hydraulic control valve comprising:
a mono type valve block; a boom spool for actuating a boom, the boom spool slidably coupled to the mono type valve block and configured to be shifted to control the hydraulic fluid supplied from a first hydraulic pump and a second hydraulic pump to the actuator, and comprising an internal path disposed in an axis direction thereof; wherein the hydraulic pump comprises a first supply path, and the second hydraulic pump comprises a second supply path, and wherein the first supply path and the second supply path are vertically symmetrical with respect to each other about an axis of the boom spool; first check valves elastically supported, and configured to open or close each of the supply path and the second supply path; bridge paths disposed to be horizontally and vertically symmetrical with respect to each other about a path disposed on a sliding surface of the mono type valve block, in which the boom spool is shifted, to supply the hydraulic fluid from the first supply path and the second supply path to the actuator; cylinder paths configured to supply the hydraulic fluid from the first hydraulic pump to the actuator when the boom spool is shifted to a first side to make the cylinder paths communicate with the bridge paths; a connection path configured to supply the hydraulic fluid from the second hydraulic pump to the internal path of the boom spool when the boom spool is shifted to the first side to make the connection path communicate with the bridge path; and a spool land of the boom spool, the spool land configured to clog the bridge paths so that, when the boom spool is shifted for lowering the boom, the hydraulic fluid of the second hydraulic pump is not supplied to the actuator of the boom, wherein, only when the boom spool is shifted for lifting up the actuator of the boom, the hydraulic fluids from the first and second hydraulic pumps are in a confluent state via the bridge paths. |
