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| Illustration 1 | g06261483 |
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Location of the speed control valve group | |
The hydraulic cylinder that operates the jaw is equipped with a speed control valve. The speed control valve is used to adjust the cylinder for use with maximum power or for use in high speed. The resistance that acts against the cylinder will determine the proper mode of operation. The speed control valve is mounted to the bottom side of the cylinder.
Closing the Jaw (High Speed Operation)
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| Illustration 2 | g06311902 |
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(AA) Cavity
(BB) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (1) Sequence valve (2) Check valve (3) Check valve (4) Intensifier valve (5) Cylinder (6) Regeneration valve (7) Intensifier valve (8) Intensifier piston group (9) Check valve (10) Check valve (11) Check valve (12) Check valve (13) Relief valve (14) Relief valve (15) Pilot valve (16) Check valve (17) Spring (18) Auxiliary control valve | |
When the hydraulic cylinder closes the jaw under no resistance, the speed control valve will shift into a high speed operation.
When the operator starts to close the jaws, auxiliary control valve (18) directs oil flow from the host machine through the speed control valve to the head end of cylinder (5). Since the hydraulic cylinder initially closes the jaw under no resistance, supply oil will flow through check valve (16) forcing regeneration valve (6) to the right. Spring (17) keeps pilot valve (15) shifted to the left. Oil pressure on the head end of cylinder (5) causes the rod to extend, which closes the jaws.
With regeneration valve (6) shifted to the right, return oil from the rod end of cylinder (5) is sent back to the head end. High-pressure oil is at both sides of the piston, but the extra surface area at the head end causes the piston to move to the right. The extra flow that is supplied to the head end causes an increase in speed. The increase in speed results in a decrease in closing time.
Simultaneously, oil flows to relief valves (13) and (14), and to intensifier valves (4) and (7). Spring force keeps the relief valves closed when the pressure is below the relief valve setting point. Since regeneration valve (6) is shifted to the right, no oil will be sent to sequence valve (1). When sequence valve (1) is not supplied with oil pressure, intensifier valves (4) and (7) will not be activated.
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| Illustration 3 | g06311971 |
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(AA) Cavity
(BB) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (1) Sequence valve (2) Check valve (3) Check valve (4) Intensifier valve (5) Cylinder (6) Regeneration valve (7) Intensifier valve (8) Intensifier piston group (9) Check valve (10) Check valve (11) Check valve (12) Check valve (13) Relief valve (14) Relief valve (15) Pilot valve (16) Check valve (17) Spring (18) Auxiliary control valve | |
When cylinder (5) closes the jaw under high resistance, the speed control valve will shift into a power operation known as "Power Mode". This mode will activate the two intensifier valves.
When the operator closes the jaw, auxiliary control valve (18) shifts to the right. When auxiliary control valve (18) is shifted to the right, flow is directed from the host machine through the speed control valve to the head end of cylinder (5). The pressure on the head end of cylinder (5) causes the cylinder rod to extend, which closes the jaws.
Simultaneously, oil flows to relief valve (14), pilot valve (15), regeneration valve (6), intensifier (4) and intensifier (7). Spring force keeps relief valve (14) closed when oil pressure is below the relief setting.
The increased resistance from crushing material with the jaws of the work tool, causes an increase in oil pressure that is sensed in the speed control valve.
This pressure increases and eventually overcomes the setting of relief valve (14). The setting of relief valve (14) is
When regeneration valve (6) moves to the left, oil is directed from the rod end of cylinder (5) back to the hydraulic tank. The direction of the oil flow to the tank causes the speed of the jaws to decrease. When regeneration valve (6) moves to the left, oil is also sent to sequence valves (1).
When maximum host machine pressure is lower then cylinder pressure, check valve (12) closes. This condition is the start of the "Boost mode". When maximum host pressure stays above cylinder pressure, boost mode will not be activated (resistance crushing material too low to increase oil pressure).
Note: When sequence valves (1) are supplied with oil, intensifier valves (4) and (7) are activated. An active intensifier is recognizable by a soft ticking sound in the background during jaw closing operation.
Closing the Jaw "Boost Mode" (Maximum Power)
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| Illustration 4 | g06311988 |
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(AA) Cavity
(BB) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (1) Sequence valve (2) Check valve (3) Check valve (4) Intensifier valve (5) Cylinder (6) Regeneration valve (7) Intensifier valve (8) Intensifier piston group (9) Check valve (10) Check valve (11) Check valve (12) Check valve (13) Relief valve (14) Relief valve (15) Pilot valve (16) Check valve (17) Spring (18) Auxiliary control valve | |
When cylinder (5) closes the jaw under high resistance, the speed control valve will shift into a maximum power operation known as "Boost Mode". This mode will activate the two intensifier valves.
When the operator closes the jaw, auxiliary control valve (18) shifts to the right. When auxiliary control valve (18) is shifted to the right, flow is directed from the host machine through the speed control valve to the head end of cylinder (5). The pressure on the head end of cylinder (5) causes the cylinder rod to extend, which closes the jaws.
Simultaneously, oil flows to relief valve (14), pilot valve (15), regeneration valve (6), intensifier (4) and intensifier (7). Spring force keeps relief valve (14) closed when oil pressure is below the relief setting.
The increased resistance from crushing material with the jaws of the work tool, causes an increase in oil pressure that is sensed in the speed control valve.
This pressure increases and eventually overcomes the setting of relief valve (14). The setting of relief valve (14) is
When regeneration valve (6) moves to the left, oil is directed from the rod end of cylinder (5) back to the hydraulic tank. The direction of the oil flow to the tank causes the speed of the jaws to decrease. When regeneration valve (6) moves to the left, oil is also sent to sequence valves (1).
When maximum host machine pressure is lower then cylinder pressure, check valve (12) closes. This condition is the start of the "Boost mode". When maximum host pressure stays above cylinder pressure, boost mode will not be activated (resistance crushing material too low to increase oil pressure).
Note: When sequence valves (1) are supplied with oil, intensifier valves (4) and (7) are activated. An active intensifier is recognizable by a soft ticking sound in the background during jaw closing operation.
When activated, the piston and valve group within the intensifier valve will shuttle back and forth. This action will provide higher pressure oil to the cylinder which is required to overcome the higher resistance of crushing material.
Note: The following describes the operation of left intensifier valve (4). The operation will be the same for right intensifier valve (7).
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| Illustration 5 | g03429191 |
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Cross section and schematic views of intensifier valve (upward movement) (A) Cavity (B) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (HD) Port (outlet) (UB1) Port (inlet) (UB2) Port (inlet) (2) Check valve (3) Check valve (8) Intensifier piston group (9) Check valve (10) Check valve (19) Passage (20) Check valve (21) Check valve | |
Supply oil is sent to intensifier valve (4) through sequence valve (1). When sequence valves (1) are shifted downward, oil travels through passage (C). Simultaneously, supply oil will flow to cavity (A) through check valve (10) and check valve (21).
As intensifier piston group (8) is forced upward by oil from passage (C) and passage (UB2), oil in cavity (B) will be forced to the head end of cylinder (5) through check valve (2). This action nearly doubles the pressure of the pump oil.
Note: The following describes the operation of left intensifier valve (4). The operation will be the same for right intensifier valve (7).
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| Illustration 6 | g03414901 |
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Cross section and schematic views of intensifier valve (switching direction) (A) Cavity (B) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (HD) Port (outlet) (UB1) Port (inlet) (UB2) Port (inlet) (2) Check valve (3) Check valve (8) Intensifier piston group (9) Check valve (10) Check valve (19) Passage (22) Passage | |
As intensifier piston group (8) reaches the upward position, pump supply oil enters passage (W) from cavity (B) through passage (22). Supply oil that enters passage (W), will shift sequence valves (1) Downward. When sequence valves (1) shift to thedownwardposition, pump oil flows to intensifier valve (4) and intensifier valve (7) through passage (D).
This action will begin the downward movement of intensifier piston group (8).
Note: The following describes the operation of left intensifier valve (4). The operation will be the same for right intensifier valve (7).
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| Illustration 7 | g03415099 |
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Cross section and schematic views of intensifier valve (downward movement) (A) Cavity (B) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (HD) Port (outlet) (UB1) Port (inlet) (UB2) Port (inlet) (2) Check valve (3) Check valve (8) Intensifier piston group (9) Check valve (10) Check valve (19) Passage (20) Check valve (21) Check valve (23) Passage | |
The cycle repeats as sequence valves (1) are shifted downward, oil from sequence valve (1) now flows to intensifier (4) through passage (D). Simultaneously, supply oil will flow to cavity (B) through check valve (9) and check valve (20).
As intensifier piston group (8) is forced downward by oil from passage (D) and passage (UB1), oil in cavity (A) will be forced to the head end of cylinder (5) through check valve (10). This action nearly doubles the pressure of the pump oil.
Intensifier piston group (8) will continue the downward movement until passage (23) is open to both cavity (A) and passage (V).
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| Illustration 8 | g06312019 |
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(AA) Cavity
(BB) Cavity (C) Passage (D) Passage (V) Passage (W) Passage (1) Sequence valve (2) Check valve (3) Check valve (4) Intensifier valve (5) Cylinder (6) Regeneration valve (7) Intensifier valve (8) Intensifier piston group (9) Check valve (10) Check valve (11) Check valve (12) Check valve (13) Relief valve (14) Relief valve (15) Pilot valve (16) Check valve (17) Spring (18) Auxiliary control valve | |
When the operator opens the jaw, auxiliary control valve (18) shifts to the left. Auxiliary valve (18) directs oil flow from the host machine through the speed control valve to the rod end of cylinder (5).
The oil flows to both sides of pilot valve (15). The pressure on the right side of pilot valve (15) with spring (17), holds the valve to the left. Oil then flows through pilot valve (15) to both sides of regeneration valve (6). The regeneration valve (6) will not shift because of the equal pressure applied to both sides. Check valve (11) keeps the supply oil from going to sequence valves (1). The oil pressure that acts on the rod side of cylinder (5) retracts the rod, which opens the jaws. Oil from the head end of cylinder (5) returns to the hydraulic tank.