Excavator solenoid valve set 423-4562 proportional solenoid valve

Electromagnetic proportional valve working principle and detection:

Valve control of flow can be divided into two types:
One is switch control: either fully open or fully closed, the flow rate is either large or small, there is no intermediate state, such as ordinary electromagnetic through valves, electromagnetic reversing valves, electro-hydraulic reversing valves.
The other is continuous control: the valve port can be opened according to the need of any degree of opening, thereby controlling the size of the flow through, such valves have manual control, such as throttle valves, but also electronically controlled, such as proportional valves, servo valves.
So the purpose of using proportional valve or servo valve is: to achieve the flow control by electronic control (of course, after structural changes can also achieve pressure control, etc.), since it is throttling control, there must be energy loss, servo valve and other valves are different, its energy loss is greater, because it needs a certain flow to maintain the work of the pre-stage control oil circuit.

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. coil
When electricity is applied, 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 plunger stroke and valve opening, and the valve opening (flow) and the coil current (control signal) 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.