52
TRENCHING VALVE
DESCRIPTION
The trenching valve is specially designed to convert the Kanga Loader together with the trencher
attachment into a high performance trenching machine. The valve provides load sensing to ensure
the trencher travel speed stays balanced to the trencher cutting speed regardless
of the ground conditions.
The trencher valve assembly comprises a group of cartridges forming a complex circuit. Servicing
and repair to the trencher valve is usually restricted to cartridge element replacement.
CIRCUIT DESCRIPTION
When starting the trenching chain (Aux. Lever down) oil is flowing to VLV A port of the trencher valve.
Priority oil flows through the flow control valve (1) and pressure compensator (2) to VLV B port and
back to the main control valve for use by the drive motors. Trenching travel speed is adjusted by
the flow control valve (1) with speed being constant regardless of trenching and travel loads. Once
the priority flow requirements are satisfied excess flow is permitted to flow through the pressure
compensator (2) to the A port and to the trencher motor.
NOTE:
If the flow control valve (1) is fully closed all flow is directed to the trencher motor and no oil
can flow to the drive motors; no regulating occurs.
Return oil from the trencher motor flows through the C port and the over centre valve (3) to the Tank
(T) port.
In the event of excessively hard trenching with the drive motor driving against the trenching chain
the drive circuit pressure will rise above the setting of the sequence valve (4) and it oil will get
diverted to the tank. In this condition a constant load is held against the trenching chain by the drive
motors. When reversing the trencher chain (Aux. Lever up) eg. to clear the chain from rocks or wood,
oil flow is directed to port VLV B. System pressure will rise to the setting of the sequence valve (4)
and then flow will get diverted to port C and therefore reversing the trencher motor.
NOTE:
If the flow control valve (1) is fully closed all flow is directed to the trencher motor and no oil
can flow to the drive motors; no regulating occurs.
Return oil from the trencher motor flows through the C port and the over centre valve (3) to the Tank
(T) port.
Sequence Valve (4)
Pressure Compensator (2)
Flow Control (1)
Overcentre Valve (3)
Summary of Contents for 8D Series
Page 1: ...8D SERIES OPERATOR S MANUAL WWW KANGALOADER COM 1300 4 KANGA PM 000130 ...
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Page 69: ...69 DIMENSIONS 8 SERIES ...
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