Excavator hydraulic pump solenoid valve proportional solenoid valve TM68401

Characteristics of proportional solenoid valves

1) It can realize the stepless adjustment of pressure and speed, and avoid the impact phenomenon when the normally open switch valve is reversed.

2) Remote control and program control can be realized.

3) Compared with intermittent control, the system is simplified and the components are greatly reduced.

4) Compared with the hydraulic proportional valve, it is small in size, light in weight, simple in structure and low in cost, but its response speed is much slower than the hydraulic system, and it is also sensitive to load changes.

5) Low power, low heat, low noise.

6) There will be no fire and no environmental pollution. It is less affected by temperature changes.

Principle of proportional solenoid valve

It is based on the principle of the solenoid switch valve: when the power is cut off, the spring presses the iron core directly against the seat, closing the valve. When the coil is energized, the resulting electromagnetic force 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 on-off valve: the spring force and the electromagnetic force are balanced 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 opening of the valve, and the opening of the valve (flow rate) and the coil current (control signal) have an ideal linear relationship. Direct acting proportional solenoid valves flow under the seat. The medium flows under the valve seat, and its direction of force is the same as the electromagnetic force, but the opposite of the spring force. Therefore, it is necessary to set the sum of the small flow values corresponding to the operating range (coil current) in the operating state. When the power is off, the Drake liquid proportional solenoid valve is closed (normally closed).