GLASS-DOOR 5327731 - Caterpillar

Illustration 1 g01530960
(1) Hydraulic pedal
(2) Line relief valve for the work tool
(3) Proportional solenoid valve for negative flow control
(4) Implement/swing pressure switch
(5) Line for the work tool (Return)
(6) Line for the work tool (Supply)
(7) Main control valve
(8) Attachment control valve
(9) Pilot manifold
(10) Hydraulic tank
(11) Drive pump
(12) Pilot pump The default parameter values for "System 1" are for one-way hydraulic oil flow from one main pump. Refer to Testing and Adjusting, "System 1: Default Value of Work Tool Parameters" for the Tool Control System.The flow to the work tool can be set by using the monitor or ET.The work tool is operated by right foot pedal (1).
Illustration 2 g01243522
Right Foot pedal for the work tool
Pilot pump (12) supplies oil to pilot manifold (9). When the hydraulic activation lever is moved to the UNLOCK position, pilot oil flows from pilot manifold (9) to right foot pedal (1). When right foot pedal (1) is depressed to the FORWARD position, pilot oil flows to the top of attachment control valve (8). The pilot oil shifts the attachment control valve to the DOWNWARD position. This allows oil from drive pump (11) to flow through the valve. The pump oil flows through the supply line for the work tool (6) to the work tool. The working pressure for the work tool is controlled by relief valve (2). Return oil flows through the return line for the work tool (5) and back to hydraulic tank (10).During the operation of the work tool, implement/swing pressure switch (9) senses pilot pressure.Implement/swing pressure switch (4) signals the machine electronic control module. The machine ECM sends a signal to the proportional solenoid valve for negative flow control (3). Negative flow control pressure in the center bypass passage is blocked when the attachment control valve shifts DOWNWARD. The machine ECM calculates the minimum negative flow control pressure that will be supplied to the pump regulator. When the work tool is activated, proportional solenoid valve (3) receives a signal from the machine ECM. The signal is a result of the calculation. Pilot oil is directed from the proportional solenoid valve (3) through the lines for negative flow control to the pump regulator. The negative flow control pressure positions the swashplate in the pump to the correct angle in order to provide the desired oil flow to the work tool.