COMPONENT OPERTATION / Control Valve Flow Rate Control Operation 1. Pilot pressure from solenoid valve unit (SF) shifts the switch valve in boom flow rate control valve. 2. As pressure oil from pump 1 acts on the piston through switch valve, the piston moves downward (upward in the circuit diagram). 3. Therefore, back pressure in the poppet increases and the force to close the poppet valve appears. 4. Consequently, the poppet restricts flow rate to the boom 1 spool and pressure oil is supplied to other actuators which load pressure is higher at.
Boom Cylinder To Regenerative Circuit in Boom 2 Spool Poppet Pressure Oil from Pilot Pump Switch Valve Pressure Oil from Solenoid Valve Unit (SF) Pressure Oil from Pump 1 (Parallel Circuit) T450-03-03-047 T3-3-38