Multi way valve consists of two sets of valve blocks
Slewing, standby, stick and left travel reversing valves are in one valve group and supplied by one pump (PL is the oil inlet); The boom, bucket and right travel reversing valve are in a valve group and supplied with oil by a pump (PR is the oil inlet).
Each directional valve is controlled by pilot control oil.
Features of the multi-channel valve:
The boom rises and converges, and the upper and lower stick converges (when the boom does not rise); The boom and stick circuits are respectively provided with holding valves to prevent natural sliding; The boom lowering circuit is equipped with a regenerative oil makeup circuit (return oil back pressure valve + oil makeup check valve), and the stick lowering circuit is equipped with a regenerative oil makeup circuit (return oil throttle valve + oil makeup check valve) to maintain the boom and stick lowering continuity.
A negative flow control valve is installed on the middle return oil passage of each of the two valve groups. When each spool of the multi-channel valve is in the middle or slightly opened, the boom is lowered, or the bucket excavation is blocked, the pressure signal generated by the negative flow control valve is sent to the main pump, so as to automatically reduce the displacement of the main pump.
The main oil inlets PR and P1 of the multi-way valve are connected to the connection ports FR and F1 of the negative flow control of the pump and the connection port r of the oil return tank; Connecting ports al1 and BL1 with each hydraulic action element And AR1, BR1; And the pilot control oil connection interfaces al1 and BL1 of each valve And AR1, br, And oil return ports DR1, DR2 And pilot control oil to each valve stem. In order to reduce the pipeline, reduce the fluid resistance and facilitate the connection of the whole oil circuit, some components belonging to the oil circuit of each hydraulic element are also integrated on the valve.
For example: safety valve, overload valve, boom and stick hold valve, regeneration makeup valve, etc.
The multi-channel valve is only equipped with one main safety valve (Z valve, 32Mpa) to control the maximum working pressure of boom, bucket, stick and travel; The maximum working pressure of slewing (27.5mpa) is controlled by two buffer valves of slewing motor.
The boom reversing valve, bucket reversing valve and stick reversing valve are connected in parallel with a pair of overload valves (36Mpa), and the standby control valve is connected in parallel with a pair of safety valves (20MPa).
