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| Illustration 1 | g06012833 |
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Partial hydraulic schematic (swing boom RIGHT) (1) Swing boom cylinder (2) Main control valve (3) Relief valves (4) Swing boom control valve (5) Hydraulic pump (6) Hydraulic tank (15) HPU changeover valve | |
The swing boom is used to dig in locations that prevent the upper structure from swinging. The swing boom function is controlled manually, by a foot pedal.
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| Illustration 2 | g02470257 |
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Swing boom hydraulic system (swing RIGHT) (1) Swing boom cylinder (2) Main control valve (8) Swing boom bracket | |
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| Illustration 3 | g02470638 |
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Location of swing boom foot pedal (8) | |
Supply oil is routed from hydraulic pump (5) to main control valve (2). The supply oil flows through swing boom control valve (4). Pump oil then flows to the rod end of swing boom cylinder (1). This action causes the cylinder rod to retract. The retracting of the cylinder rod causes the boom to swing right.
Return oil from the head end of swing boom cylinder (1) flows to the return hydraulic system and hydraulic tank (6).
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| Illustration 4 | g02471296 |
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Control valve (swing boom RIGHT) (9) Cylinder port A (10) Cylinder port B (11) Return passage (12) Spool (13) Center bypass passage (14) Parallel feeder passage | |
Spool (12) has a mechanical linkage which actuates the valve. When the linkage is pressed, spool (12) shifts upward. The pump oil then flows to cylinder port A (9). The oil flows through lines to the rod end of the boom swing cylinder to retract the cylinder rod. Return oil in cylinder port B (10) flows through the spool to return passage (11). The oil then returns to the tank.
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| Illustration 5 | g02472196 |
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Control valve (swing boom LEFT) (9) Cylinder port A (10) Cylinder port B (11) Return passage (12) Spool (13) Center bypass passage (14) Parallel feeder passage | |
Spool (12) has a mechanical linkage which actuates the valve. When the linkage is pressed, spool (12) shifts downward. The pump oil then flows to cylinder port B (10). The oil flows through lines to the head end of the boom swing cylinder to extend the cylinder rod. Return oil in cylinder port A (9) flows through the spool to return passage (11). The oil then returns to the tank.