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| Illustration 1 | g01518748 |
Implement control valve (felling head) (1) Inlet section (2) Boom control valve (3) Tilt control valve (4) Stick control valve (5) Swing control valve (6) Control valve (grapple arms) (7) Control valve (accumulator arms) (8) Control valve (tool) (9) End section | |
The track feller bunchers come in three types of arrangements: the felling head, the harvester head and the intermittent saw
Note: The control valve for the intermittent saw uses the same functions as the felling head.
Felling Head Arrangement
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| Illustration 2 | g01460778 |
Implement control valve (1) Inlet section (2) Boom control valve (3) Tilt control valve (4) Stick control valve (5) Swing control valve (6) Control valve (grapple arms) (7) Control valve (accumulator arms) (8) Control valve (tool) (9) End section | |
The implement control valve is a load sensing bank valve. The implement control valve consists of seven control valves. The control valves are the boom, the tilt, the stick, the swing, the grapple arms, the accumulator arms, and the tool.
All of the control valves are controlled by proportional solenoid valves. The proportional solenoid valves are activated by the joystick controls inside the cab. All of the control valves are actuated by pilot oil. When the operator moves a function, the pilot oil controls the movement of the closed center valve spools. The valve spools are spring centered.
All of the control valves have line relief valves except the swing control valve. The swing control valve has anticavitation valves. The line relief valves are located on the swing motor.
The following control valves have signal limiter valves:
- Tilt
- Swing
- Grapple arms
- Accumulator arms
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| Illustration 3 | g01518788 |
Top view of the implement control valve (7 bank) (10) Air purge valves (11) Signal limiter valves (12) Line relief valves (13) Proportional solenoid TILT LEFT (14) Proportional solenoid TILT RIGHT (17) Pressure differential relief valve (19) Main relief valve (P1) Inlet from pump (B1) Boom DOWN (B2) Tilt LEFT (B3) Stick IN (B4) Swing LEFT (B5) Grapple arms OPEN (B6) Accumulator arms OPEN (B7) Tool DOWN (A1) Boom UP (A2) Tilt RIGHT (A3) Stick OUT (A4) Swing RIGHT (A5) Grapple arms CLOSE (A6) Accumulator arms CLOSE (A7) Tool UP (T1) Return to hydraulic tank | |
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| Illustration 4 | g01518819 |
View A-A (P1) Inlet port from the implement pump (T1) Outlet port to the hydraulic tank (PL) Signal port to the implement pump (PS) Pilot port to the proportional solenoids | |
Pressure oil from the implement pump flows into the implement control valve through port (P1) to the inlet section of the implement control valve.
The pressure oil from the implement pump flows to the signal duplication valve, to the pressure differential relief valve and to all of the control valves.
The pressure differential relief valve increases the pressure oil from the implement pump to 4000 kPa (580 psi), when no functions are activated. The implement pump strokes to standby pressure. The pressure differential relief valve is adjustable.
As the function moves, the pressure oil and the flow that is required from the implement pump changes. A series of ball resolver valves direct the highest work port pressure to the implement pump. The required pressure is sensed in the load sensing system by the implement pump at port (PL) .
Note: A pressure tap is located at the implement pump for measuring the signal pressure.
If air enters the pilot hydraulic system, the spools may not move smoothly. The air can be removed from the system, when the engine is running, through air purge valves (10).
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| Illustration 5 | g01518833 |
View B-B (P2) Inlet port from the implement pump (T3) Port to the hydraulic tank (TP) Port to the hydraulic tank | |
Pressure oil from the implement pump flows into the implement control valve through port (P2) .
Return oil that bypasses the oil cooler flows from the implement control valve through port (T3) back to the hydraulic tank. Return pilot oil flows from the implement control valve through port (TP) to the travel control valve.
The following explanation is for the tilt function of the implement control valve. The other sections of the implement control valve operate similarly. The pressure settings of the line relief valves and the signal limiter valves are different for the other sections of the implement control valve. The line relief valves are not adjustable. The control valve spools are actuated by pilot oil from the pilot hydraulic system.
ReferenceFor more information on the pilot hydraulic system, see Systems Operation/Testing and Adjusting, "Pilot Hydraulic System".
ReferenceFor more information on the implement control valve, refer to Schematic, RENR8939.
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| Illustration 6 | g01066739 |
Partial schematic of the implement control valve (tilt section) (11) Signal limiter valves (12) Line relief valves (13) Proportional solenoid (14) Proportional solenoid (15) Orifices (16) Signal duplication valve (17) Pressure differential relief valve (18) Inlet section (19) Main relief valve (20) Pressure compensator valve (21) Orifice (22) Spool (23) Tilt control valve (24) Resolver (25) End section | |
When a circuit is deactivated the load sensing pressure on pressure differential relief valve (17) decreases. When the function is not activated, there is no load sensing pressure that is sent to the implement pump. Pressure differential relief valve (17) is opened by the pressure oil from the implement pump. Pressure differential relief valve (17) reduces the pressure oil from the implement pump at port (P1) to standby pressure. The pressure differential relief valve is adjustable.
Main relief valve (19) controls the maximum load sensing pressure in the implement control valve. The pressure setting of the main relief valve is set at 35500 kPa (5150 psi). When the load sensing pressure in the implement control valve exceeds the pressure setting of the main relief valve, the main relief valve opens. Pressure oil flows to the hydraulic oil tank.
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| Illustration 7 | g01518854 |
View C-C (10) Air purge valves (11) Signal limiter valves (12) Line relief valves (20) Pressure compensator valve (21) Orifice (22) Spool | |
HOLD Position
When the trigger switch for the tilt function is not activated, valve spool (22) is in the HOLD position. Pressure compensator valve (20) contains a load hold check valve. The check valve prevents the tilt cylinders from moving. No oil will flow to the cylinders or from the cylinders.
Line relief valves (12) protect the tilt cylinders and hydraulic oil lines from damage. When an external load acts on the machine, the oil pressure in the circuit increases. When the pressure in the circuit exceeds the relief valve pressure setting, the line relief valve opens. The oil in the circuit returns to the hydraulic oil tank. The check valves in the line relief valves prevent cavitation in the cylinders.
The signal pressure oil drains from pressure compensator valve (20). Pressure differential relief valve (17) sets the signal pressure. The signal pressure strokes the implement pump to standby pressure.
Tilt LEFT
When the operator presses the trigger switch on the left joystick UP for tilt cylinder LEFT, a signal is sent to the IQAN controller. The IQAN controller sends current to proportional solenoid (13). The pilot oil flows through proportional solenoid (13) and orifice (15) to valve spool (22). Orifice (15) prevents the valve spool from moving rapidly. The valve spool shifts.
Note: Press the trigger switch downward on the right joystick in order to activate the tilt cylinder LEFT.
The pressure oil from the implement pump flows through pressure compensator valve (20). The oil flows to the head end of the tilt cylinder. Regardless of the implement pump pressure, the pressure compensator valve maintains constant oil flow to the tilt cylinder.
Line relief valves (12) prevent cavitation. The check valve lifts up in order to allow oil from the return passage to flow into the hydraulic oil line and the tilt cylinder.
Pressure oil also flows into the circuit for the signal pressure. Signal limiter valves (11) limit the pressure in the signal circuit. The pressure setting of the signal limiter valve controls the maximum pressure signal to the implement pump. The pressure setting is adjustable.
Tilt RIGHT
When the operator presses the trigger switch on the left joystick UP for tilt cylinder RIGHT, a signal is sent to the IQAN controller. The IQAN controller sends current to proportional solenoid (14). The pilot oil flows through proportional solenoid (14) and orifice (15) to valve spool (22). Orifice (15) prevents the valve spool from moving rapidly. The valve spool shifts.
Note: Press the trigger switch upward on the right joystick in order to activate the tilt cylinder RIGHT.
The pressure oil from the implement pump flows through pressure compensator valve (20). The oil flows to the rod end of the tilt cylinder. Regardless of the implement pump pressure, pressure compensator valve (20) maintains constant oil flow to the tilt cylinder.
Line relief valves (12) prevent cavitation. The check valve lifts up in order to allow oil from the return passage to flow into the hydraulic oil line and the tilt cylinder.
Pressure oil also flows into the circuit for the signal pressure. Signal limiter valves (11) limit the pressure in the signal circuit. The pressure setting of the signal limiter valve controls the signal to the implement pump. The pressure setting is adjustable.
Signal pressure oil also flows to the pressure compensator valve. Orifice (21) limits the response of the pressure compensator to the load signal. Resolver (24) directs the highest signal pressure to the inlet section of the implement control valve.
The load sensing signal pressure flows out of port (PL) to the implement pump. The load sensing signal pressure upstrokes the implement pump.
The load sensing signal pressure forces pressure differential relief valve (17) to close.
Arrangement for the Harvester Head
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| Illustration 8 | g01461387 |
Implement control valve (7 bank) (1) Inlet section (2) Boom control valve (3) Rotator control valve (4) Stick control valve (5) Swing control valve (6) Control valve (7) Control valve (8) Control valve (9) End section | |
The implement control valve is a load sensing bank valve. The implement control valve consists of seven control valves. The control valves are the boom, the rotator, the stick, the swing and the control valves for the harvester head.
All of the control valves are controlled by proportional solenoid valves. The proportional solenoid valves are activated by the joystick controls inside the cab. All of the control valves are actuated by pilot oil. When the operator moves a function, the pilot oil controls the movement of the closed center valve spools. The valve spools are spring centered.
All of the control valves have line relief valves except the swing control valve. The line relief valves are located on the swing motor.
The following control valves have signal limiter valves:
- Swing
- Rotator
- Control valves for the harvester head
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| Illustration 9 | g01518875 |
Top view of the implement control valve (7 bank) (8) Air purge valves (9) Line relief valves (10) Proportional solenoid ROTATE COUNTERCLOCKWISE (11) Proportional solenoid ROTATE CLOCKWISE (14) Pressure differential relief valve (16) Main relief valve (P1) Inlet from pump (B1) Boom DOWN (B2) Rotator CLOCKWISE (B3) Stick IN (B4) Swing LEFT (B5) Saw (B6) Saw (B7) This port is not used. (A1) Boom UP (A2) Rotator COUNTERCLOCKWISE (A3) Stick OUT (A4) Swing RIGHT (A5) This port is not Used. (A6) Saw (A7) This port is not Used. (T1) Return to hydraulic tank | |
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| Illustration 10 | g01518881 |
View A-A (P1) Inlet from the implement pump (T1) Outlet port to the hydraulic tank (PX) Port to the load sensing valve (PL) Signal port to the implement pump (PS) Pilot port to the proportional solenoids | |
Pressure oil from the implement pump flows into the main control valve through port (P1) to the inlet section of the implement control valve.
The pressure oil from the implement pump flows to the signal duplication valve, to the pressure differential relief valve and to all of the control valves.
The pump oil flows out of port (PX) to the load sensing valve.
The pressure differential relief valve increases the pressure oil from the implement to 4000 kPa (580 psi), when no functions are activated. The implement pump strokes to standby pressure. The pressure differential relief valve is adjustable.
As the function moves, the pressure oil and the flow that is required from the implement pump changes. A series of ball resolver valves direct the highest work port pressure to the implement pump. The required pressure is sensed in the load sensing system by the implement pump at port (PL) .
Note: A pressure tap is located at the implement pump for measuring the signal pressure.
If air enters the pilot hydraulic system, the spools may not move smoothly. The air can be removed from the system, when the engine is running, through air purge valves (8).
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| Illustration 11 | g01518893 |
View B-B (P2) Inlet port from the implement pump (T3) Port to the hydraulic tank (TP) Port to the hydraulic tank (LSPB) Port to the load sensing valve | |
Pressure oil from the implement pump flows into the implement control valve through port (P2) .
Return oil that bypasses the oil cooler flows from the implement control valve through port (T3) back to the hydraulic tank. Return pilot oil flows from the implement control valve through port (TP) to the travel control valve.
Oil flows from the load sensing valve through port (LSPB) to the resolver network of the implement control valve.
The following explanation is for the function of the rotator of the implement control valve. The other sections of the implement control valve operate similarly. The pressure settings of the line relief valves and the signal limiter valves are different for the other sections of the implement control valve. The control valve spools are actuated by pilot oil from the pilot hydraulic system.
ReferenceFor more information on the pilot hydraulic system, refer to Systems Operation/Testing and Adjusting, "Pilot Hydraulic System".
ReferenceFor more information on the implement control valve, refer to Schematic, RENR8939.
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| Illustration 12 | g01086812 |
Partial schematic of the implement control valve (section on rotator) (9) Line relief valves (10) Proportional solenoid (11) Proportional solenoid (12) Orifices (13) Signal duplication valve (14) Pressure differential relief valve (15) Inlet section (16) Main relief valve (17) Pressure compensator valve (18) Orifice (19) Spool (20) Rotator control valve (21) Resolver (22) End section | |
When a function is deactivated the load sensing pressure on pressure differential relief valve (14) decreases. When the function is not activated there is no load sensing pressure that is sent to the implement pump. The implement pump will destroke. Pressure differential relief valve (14) is opened by the pressure oil from the implement pump. Pressure differential relief valve (14) reduces the pressure oil from the implement pump at port (P1) to standby pressure. The pressure differential relief valve is adjustable.
Main relief valve (16) controls the maximum load sensing pressure in the implement control valve. The pressure setting of the main relief valve is set at 35500 kPa (5150 psi). When the load sensing pressure in the implement control valve exceeds the pressure setting of the main relief valve, the main relief valve opens. Pressure oil flows to the hydraulic oil tank.
For information on the operation of the rotator control valve, refer to the tilt section in the felling head arrangement. The control valve operates in the same manner.