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| Illustration 1 | g00794957 |
Schematic of Dual Tilt Control Valve in Dual Tilt position (1) Line from the bulldozer tilt control valve (2) Dual tilt cylinder (left) (3) Dual tilt cylinder (right) (4) Passage to tank for solenoid valve (5) Passage for pilot oil to the solenoid valve (6) Switch handle (7) Solenoid valve (8) Coil for tip operation of the cylinders (9) Coil for single tilt operation of the cylinders (10) Passage for pilot oil (11) Passage for pilot oil (12) Chamber for pilot oil (13) Chamber for pump oil from the bulldozer tilt control valve (14) Port to head end of right dual tilt cylinder (15) Port to rod end of right dual tilt cylinder (16) Chamber for pump oil from the bulldozer tilt control valve (17) Chamber for pilot oil (18) Stem in dual tilt control valve (19) Port to rod end of left dual tilt cylinder (20) Line from the bulldozer tilt control valve (21) Dual tilt control valve | |
Dual tilt control valve (21) is an attachment. The valve gives the hydraulic circuit for the tilt cylinder three different types of operation: DUAL TILT, SINGLE TILT and TIP. The control valve is installed in the radiator guard. The valve is activated by pilot oil pressure from the pilot control lever for the bulldozer. Solenoid valve (7) directs the pilot oil to the ends of stem (18). Switch handle (6) controls the operation of the solenoid valve with a toggle switch for SINGLE TILT operation and a trigger switch for TIP operation.
Dual Tilt Operation
When solenoid valve (7) is not energized by switch handle (6), dual tilt control valve (21) is in the DUAL TILT position. Tilt cylinders (2) and (3) will move in opposite directions.
When the bulldozer control lever is moved to the TILT RIGHT position, pump oil from the bulldozer tilt control valve is sent through line (1) to the head end of dual tilt cylinder (2). As cylinder (2) extends, oil from the rod end flows to port (19) of the dual tilt control valve. The oil then flows around stem (18) through port (15) to the rod end of dual tilt cylinder (3). As cylinder (3) retracts, oil from the head end of the cylinder flows to port (14) of the dual tilt control valve. The oil then flows around stem (18) to chamber (13). Then, the oil flows to the tank through line (20) and through the bulldozer tilt control valve. The action of the two dual tilt cylinders causes the bulldozer to tilt to the right. When the control lever is released, oil is blocked to the cylinders and the bulldozer will stay tilted to the right until the control lever is moved again.
To tilt the bulldozer to the left, the bulldozer control lever is moved to the TILT LEFT position. Pump oil from the bulldozer tilt control valve is sent through line (20) to chambers (13) and (16). Since oil to chamber (16) is stopped, the oil flows to chamber (13) and around stem (18) to port (14). Oil then flows to the head end of dual tilt cylinder (3). As the cylinder extends, oil from the rod end of cylinder (3) flows to port (15). Oil at port (15) flows around stem (18) to port (19). Then, the oil flows to the rod end of dual tilt cylinder (2). As the cylinder retracts, oil from the head end of cylinder (2) flows to the tank through line (1) and the bulldozer tilt control valve. The action of the two dual tilt cylinders causes the bulldozer to tilt to the left. When the control lever is released, oil is blocked to the cylinders and the bulldozer will stay tilted to the left until the control lever is moved again.
Single Tilt Operation
When the toggle switch on switch handle (6) is moved to the ON position, coil (9) is energized. Pilot oil from the implement control valve in passage (5) flows through the solenoid valve to passage (11). Oil through passage (11) flows to chamber (12). The oil moves stem (18) downward to the SINGLE TILT position. The stem blocks oil in dual tilt cylinder (3), and the stem allows the cylinder to act as a brace. Dual tilt cylinder (2) now acts as a single tilt cylinder.
When the bulldozer control lever is moved to the TILT RIGHT position, pump oil from the bulldozer tilt control valve is sent through line (1) to the head end of dual tilt cylinder (2). As cylinder (2) extends, oil from the rod end flows to port (19) of the dual tilt control valve. The oil then flows around stem (18) to chamber (13). Then, the oil flows back to the tank through line (20) and the bulldozer tilt control valve. The action of cylinder (2) causes the bulldozer to tilt to the right. When the control lever is released, oil is blocked to cylinder (2) and the bulldozer will stay tilted to the right until the control lever is moved again.
To tilt the bulldozer to the left, the bulldozer control lever is moved to the TILT LEFT position. Pump oil from the bulldozer tilt control valve is sent through line (20) to chambers (13) and (16). Since oil to chamber (16) is stopped, the oil flows to chamber (13) and around stem (18) to port (19). Oil then flows to the rod end of dual tilt cylinder (2). As cylinder (2) retracts, oil from the head end flows to the tank through line (1) and the bulldozer tilt control valve. The action of cylinder (2) causes the bulldozer to tilt left. When the control lever is released, oil is blocked to cylinder (2) and the bulldozer will stay tilted to the left until the control lever is moved again.
Tip Operation
When the trigger lever on switch handle (6) is held backward, and the toggle switch is in the OFF position, coil (8) is energized. If the toggle switch on switch handle (6) is in the ON position and the trigger lever is pulled, coil (8) will be energized and coil (9) will be de-energized. The tip operation of the bulldozer has priority over either the dual tilt function or the single tilt function. When coil (8) is energized, pilot oil from the implement control valve in passage (5) flows through the solenoid valve to passage (10). Oil flows through passage (10) to chamber (17) and the oil moves stem (18) upward to the TIP position. Oil in chamber (12) flows through passage (11) to the solenoid valve. Then, the oil flows to the tank through passage (4). When dual tilt control valve (21) is in the TIP position, the dual tilt cylinders move in the same direction in order to tip the bulldozer forward or backward.
In order to move the bulldozer forward, the bulldozer control lever is moved to the right or TIP FORWARD position. Pump oil from the bulldozer tilt control valve is sent through line (1) to the head end of dual tilt cylinder (2). As the cylinder extends, the oil from the rod end of cylinder (2) flows to port (19) of dual tilt control valve (21). Then, the oil flows around stem (18) to port (14). Then, the oil flows to the head end of dual tilt cylinder (3). As cylinder (3) extends, rod end oil from the cylinder flows to port (15) and into chamber (16) of the control valve. Then, the oil flows to the tank through line (20) and the bulldozer tilt control valve. The action of the cylinders causes the bulldozer to tip forward. When the control lever is released, the bulldozer will stay tipped forward until the trigger lever is held and the control lever is moved again.
When the trigger lever is held and the bulldozer control lever is moved to the left or TIP BACK position, pump oil from the bulldozer control valve is sent through line (20). The oil flows to chambers (13) and (16). Since oil to chamber (13) is stopped, the oil flows to chamber (16) and around stem (18) to port (15). Oil then flows to the rod end of dual tilt cylinder (3). As cylinder (3) retracts, head end oil from the cylinder flows to port (14). The oil then flows around stem (18) to port (19) and onto the rod end of dual tilt cylinder (2). As the cylinder retracts, head end oil from cylinder (2) flows to the tank through line (1) and the bulldozer tilt control valve. The action of the cylinders causes the bulldozer to tip backward. When the control lever is released, the bulldozer will stay tipped backward until the trigger lever is held and the control lever is moved again.