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| Illustration 1 | g03423250 |
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One-Way / One or Two Pump - Electronic Control (1) Tool line relief valves (2) Attachment control valve (idler pump) (3) Hydraulic oil cooler (4) Boom 2 control valve (5) Stick 1 control valve (6) Attachment control valve (drive pump) (10) Boom 1 control valve (11) Stick 2 control valve (14) Left joystick (stick) (15) Right joystick (boom) (16) Main relief valve (17) Proportional reducing valve (Flow limit 2) (18) Proportional reducing valve (Flow limit 1) (19) Flow limit 1 pressure sensor (20) Flow limit 2 pressure sensor (21) Pilot pump (22) Drive pump (23) Idler pump (24) Main control valve (25) Proportional reducing valve (power shift pressure) (28) Boom DOWN control pressure sensor (29) Boom UP control pressure sensor (30) Stick OUT control pressure sensor (31) Stick IN control pressure sensor (34) Proportional reducing valve (A2 extend) (35) Proportional reducing valve (A1 extend) (36) Pilot manifold (37) Pilot relief valve (38) Hydraulic tank (39) Tool relief valve | |
One-Way / One or Two Pump with electronic control is designed to allow complete electronic control over the work tool. This hydraulic system allows the operator to control a work tool with a one-way flow system with from one pump or two pumps.
Hammer Return Filter (If Equipped)
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| Illustration 2 | g03423762 |
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One-Way / One or Two Pump - Electronic Control with Hammer Return Filter (2) Attachment control valve (idler pump) (3) Hydraulic oil cooler (6) Attachment control valve (drive pump) (17) Proportional reducing valve (Flow limit 2) (18) Proportional reducing valve (Flow limit 1) (19) Flow limit 1 pressure sensor (20) Flow limit 2 pressure sensor (21) Pilot pump (22) Drive pump (23) Idler pump (34) Proportional reducing valve (A2 extend) (35) Proportional reducing valve (A1 extend) (38) Hydraulic tank (39) Tool relief valve (40) Hammer filter (41) Accumulator | |
One-Way / One or Two Pump - Electronic Control with Hammer Return Filter allows the return oil from the work tool to return directly through a filter before returning to the hydraulic tank. Hammer return filter (40) removes moisture and contaminates from the oil. This system is commonly used with hammers.
Accumulator (41) is located between the filter and oil cooler (3) to provide back pressure to the return system
One-way flow from one pump can be achieved by selecting a work tool that requires one-way flow from one pump. The work tool can be selected through the monitor or by the work tool select switch. A typical example is a hammer that receives oil from one pump only.
When one pump flow is required to the work tool, the pump supplying the oil can be programmed through the monitor. The following situations are listed to increase controllability of the work tool.
- When the work tool with a boom and bucket operation is used most often, the idler pump is recommended as the supply pump.
- When the work tool with a stick and swing operation is used most often, the drive pump is recommended as the supply pump.
Reference: Refer to Testing and Adjusting, "Work Tool Parameter - Program" for the tool control system to change the settings for work tool operation.
Reference: Refer to Testing and Adjusting, "One-Way / One or Two Pumps - Electric Control: Default Value of Work Tool Parameters" for the Tool Control System to reference the factory settings.
| Operation Lever List | |
| Control | Extension |
| Right joystick thumb wheel | Push Forward |
| Electric foot pedal | Push Forward |
| Electric foot switch | Push ON |
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| Illustration 3 | g03423943 |
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One-Way Flow from One Pump (idler pump) (1) Tool line relief valves (2) Attachment control valve (idler pump) (3) Hydraulic oil cooler (4) Boom 2 control valve (5) Stick 1 control valve (6) Attachment control valve (drive pump) (10) Boom 1 control valve (11) Stick 2 control valve (16) Main relief valve (17) Proportional reducing valve (Flow limit 2) (18) Proportional reducing valve (Flow limit 1) (19) Flow limit 1 pressure sensor (20) Flow limit 2 pressure sensor (21) Pilot pump (22) Drive pump (23) Idler pump (24) Main control valve (25) Proportional reducing valve (power shift pressure) (34) Proportional reducing valve (A2 extend) (35) Proportional reducing valve (A1 extend) (36) Pilot manifold (37) Pilot relief valve (38) Hydraulic tank (39) Tool relief valve | |
The following description is made under the assumption that the drive pump is supplying oil to the work tool.
When the device for activation listed in Table 1 is pressed, the machine ECM sends a modulated signal to proportional reducing valve (35). Proportional reducing valve (35) allows pilot oil to flow to attachment control valve (6). Attachment control valve (6) shifts, allowing high-pressure oil from the drive pump to flow to the work tool.
When abnormally high pressure occurs in the line to the work tool, tool relief valve (39) opens at a set pressure. This opening will allow the high-pressure oil into the return system and back to the hydraulic tank.
Oil returning from the work tool flows through the oil cooler and back to the hydraulic tank.
During the operation of the work tool, the oil flow for the drive pump is controlled by flow limit valve (10) and the machine ECM. Since attachment control valve (2) does not shift, the idler pump is controlled by the negative flow control pressure.
One-way flow from two pumps can be achieved by selecting a work tool that requires one-way flow from two pumps. The work tool can be selected through the monitor or by the work tool select switch. A typical example is a hammer that receives oil from two pumps.
Reference: Refer to Testing and Adjusting, "Work Tool Parameter - Program" for the tool control system to change the settings for work tool operation.
Reference: Refer to Testing and Adjusting, "One-Way / One or Two Pumps - Electric Control: Default Value of Work Tool Parameters" for the Tool Control System to reference the factory settings.
| Operation Lever List | |
| Control | Extension |
| Right joystick thumb wheel | Push Forward |
| Electric foot pedal | Push Forward |
| Electric foot switch | Push ON |
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| Illustration 4 | g03423988 |
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One-Way Flow from Two Pumps (1) Tool line relief valves (2) Attachment control valve (idler pump) (3) Hydraulic oil cooler (4) Boom 2 control valve (5) Stick 1 control valve (6) Attachment control valve (drive pump) (10) Boom 1 control valve (11) Stick 2 control valve (14) Left joystick (stick) (15) Right joystick (boom) (16) Main relief valve (17) Proportional reducing valve (Flow limit 2) (18) Proportional reducing valve (Flow limit 1) (19) Flow limit 1 pressure sensor (20) Flow limit 2 pressure sensor (21) Pilot pump (22) Drive pump (23) Idler pump (24) Main control valve (25) Proportional reducing valve (power shift pressure) (34) Proportional reducing valve (A2 extend) (35) Proportional reducing valve (A1 extend) (36) Pilot manifold (37) Pilot relief valve (38) Hydraulic tank (39) Tool relief valve | |
When the device for activation listed in Table 2 is pressed, proportional reducing valve (34) and proportional reducing valve (35) receives a modulated signal from the machine ECM. Proportional reducing valve (34) allows pilot oil to flow to attachment control valve (2). Proportional reducing valve (35) allows pilot oil to flow to attachment control valve (6). This shifts attachment control valve (2) and attachment control valve (6), allowing high-pressure oil from the drive pump and the idler pump to combine and flow to the work tool.
When abnormally high pressure occurs in the line to the work tool, tool relief valve (39) opens at a set pressure. This opening will allow the high-pressure oil into the return system and back to the hydraulic tank.
Oil returning from the work tool flows through the oil cooler and back to the hydraulic tank.
During the operation of the work tool, the oil flow for both pumps is controlled by flow limit valve (17), flow limit valve (18), and the machine ECM.