Excavator accessories 702-75-04600 hydraulic valve travel relief valve

Working principle of proportional solenoid valve
It is based on the principle of the solenoid on-off valve: when the power is off, the spring presses the core directly against the seat, causing the valve to close. When the coil is energized, the electromagnetic force generated overcomes the spring force and lifts the core, thus opening the valve. The proportional solenoid valve makes some changes to the structure of the solenoid valve: it creates a balance between the spring force and the electromagnetic force under any coil current. The size of the coil current or the size of the electromagnetic force will affect the stroke of the plunger and the valve opening, and the valve opening (flow) and the coil current (control letter)
Is an ideal linear relationship.
Direct acting proportional solenoid valve flows under the seat. The medium flows in from under the seat, and the direction of the force is the same as the electromagnetic force, and the opposite of the spring force. Therefore, it is necessary to set the maximum and minimum flow values corresponding to the operating range (coil current) in the operating state. The proportional solenoid valve of the Drey fluid is closed (NC, normally closed type) when the power is off.