SWITCHING VALVE, SWITCHING HYDRAULIC SYSTEM, AND CRANE

摘要

A switching valve, switching hydraulic system, and crane. The switching valve has a working oil inlet (P) and a working oil return port (T), comprising at least two sets of valve oil ports in pair. Cartridge valves in pair are provided between each set of valve oil ports in pair and the working oil inlet (P) and provided between each set of valve oil ports in pair and the working oil return port (T). The cartridge valves are controlled to be open or closed to enable the working oil inlet (P) and the working oil return port (T) to be switched between communications with the at least two sets of valve oil ports in pair. By controlling the cartridge valves to be open or closed, the switching valve enables or disables the communication between the working oil inlet (P) and the at least two sets of valve oil ports in pair and the communication between the working oil return port (T) and the at least two sets of valve oil ports in pair, stably enabling a hydraulic pump system to switch between communications with at least two closed systems, reducing the number of pumps in a hydraulic system, greatly reducing cost of a hydraulic system and total vehicle weight, and having a higher reliability.