Enabling the Removal Device for the Counterweight
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| Illustration 1 | g02177727 |
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Upper left side of pump compartment (toggle switch, lever, and ball valves) (A) CLOSED position (B) OPEN position (4) Lever (5) Ball valve (6) Ball valve (10) Solenoid valve (25) Toggle switch | |
The hydraulic activation control lever must be in the LOCKED position in order to activate the counterweight removal circuit. Ball valves (5) and (6) must be in the OPEN position. The counterweight removal circuit is enabled by toggle switch (25).
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| Illustration 2 | g03409216 |
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Counterweight LOWER operation (1) Pilot line (2) Relief valve (3) Control valve (4) Lever (5) Ball valve (6) Ball valve (7) Counterweight lifting cylinder (8) Valve (9) Valve (10) Solenoid valve (11) Check valve (12) Boom II control valve (13) Check valve (14) Ball resolver valve (15) Pilot line (16) Main control valve (17) Return line (18) Line (pump oil delivery) (19) Pilot manifold (20) Hydraulic tank (21) Pilot oil supply line (22) Pilot pump (23) Drive pump (24) Idler pump | |
Toggle switch (25) energizes solenoid valve (10). Solenoid valve (10) shifts valve (9). Oil from idler pump (24) flows through line (18) and through valve (9) to control valve (3).
Pilot oil also flows through pilot line (15) to ball resolver valve (14). From ball resolver valve (14) the pilot oil flows to boom II control valve (12). Boom II control valve (12) shifts UPWARD. Negative flow control pressure to idler pump (24) is now blocked. This action causes idler pump (24) to upstroke.
Reference: For more information concerting negative flow control operation, refer to Systems Operation, "Negative Flow Control System".
When lever (4) is pulled DOWN, control valve (3) shifts for the counterweight LOWER operation. Pump oil flows through check valve (13) and control valve (3) to rod end of lift cylinder (7). Oil flows through ball valve (6) to open valve (8). Oil drains from the head end of lift cylinder (7) and flows through valve (8), ball valve (5), and control valve (3). The oil flows through control valve (3) and line (17) to hydraulic tank (20). The counterweight is lowered.
The pressure for the counterweight removal circuit is regulated by relief valve (2).
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| Illustration 3 | g03409439 |
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Counterweight RAISE operation (1) Pilot line (2) Relief valve (3) Control valve (4) Lever (5) Ball valve (6) Ball valve (7) Counterweight lifting cylinder (8) Valve (9) Valve (10) Solenoid valve (11) Check valve (12) Boom II control valve (13) Check valve (14) Ball resolver valve (15) Pilot line (16) Main control valve (17) Return line (18) Line (pump oil delivery) (19) Pilot manifold (20) Hydraulic tank (21) Pilot oil supply line (22) Pilot pump (23) Drive pump (24) Idler pump | |
Toggle switch (25) energizes solenoid valve (10). Solenoid valve (10) shifts valve (9). Oil from idler pump (24) flows through line (18) and through valve (9) to control valve (3).
Pilot oil also flows through pilot line (15) to ball resolver valve (14). From ball resolver valve (14) the pilot oil flows to boom II control valve (12). Boom II control valve (12) shifts UPWARD. The negative flow control pressure to idler pump (24) is now blocked. This action causes idler pump (24) to upstroke.
Reference: For more information concerting negative flow control operation, refer to Systems Operation, "Negative Flow Control System".
When lever (4) is pulled UP, control valve (3) shifts for the counterweight RAISE operation. Pump oil flows through check valve (13), control valve (3), and ball valve (5) to valve (8). Oil pressure opens check valve (11) in valve (8) and flows to the head end of lift cylinder (7). Oil drains from the rod end of lift cylinder (7) and flows through valve (3) and line (17) to hydraulic tank (20). The counterweight is raised.
The pressure for the counterweight removal circuit is regulated by relief valve (2).