Operation Valve for Transmission Gearbox 4644159347 4wg180 /200 6wg180 /200 

Electro-hydraulic proportional valve is a kind of hydraulic component between on-off hydraulic valve and servo valve. Compared with electro-hydraulic servo valve, its advantages are low price and strong anti-pollution ability. Except that it is not as good as the servo valve in terms of control accuracy and response speed, its performance and control level in other aspects are equivalent to that of the servo valve, and its dynamic and static performance is sufficient to meet the requirements of most industrial applications

1. Command components
It is a component that generates and inputs a given control signal. It can also be called a programmer or input circuit. In the presence of a feedback signal, it gives a control signal of the same form and magnitude as the feedback signal. It can also be a signal generating device or a program controller. The command signal can be set manually or programmed. The most common is the manual preset setting, and the program strobe is used during operation.
2. Compare components
Its function is to compare the given input with the feedback signal and obtain the deviation signal as the input of the electronic controller. The signals to be compared must be of the same type, and the input of the proportional electronic controller is an electrical quantity, so the feedback quantity should also be converted into the same type of electrical quantity. If you encounter different types of quantities for comparison, you must perform signal type conversion before the comparison, such as A/D or D/A conversion, or electromechanical conversion.
3. Electric controller
The electronic controller is usually called a proportional amplifier. Because the electromagnet contained in the proportional valve requires a large control current (0～800mA) and the deviation control current is small, it is not enough to drive the electromagnet to work. Therefore, power amplification of the control signal is required. Moreover, the type or shape of the deviation signal may not necessarily meet the requirements of high-performance control. The function of the electronic controller is to process, reshape and amplify the input signal to meet the control requirements of the electro-mechanical conversion device.
4. Proportional valve
The inside of the proportional valve can be divided into two parts, namely the electro-mechanical converter and the hydraulic amplifier element, and may also have the detection feedback element in the valve. Electro-mechanical converter, which is the interface component of electro-hydraulic. It converts the amplified electrical signal into a force or displacement proportional to its electrical quantity. This output force or displacement changes the control hydraulic resistance of the hydraulic amplifier stage, and the small electrical control signal is amplified enough to drive the system load through hydraulic amplification. This is the power amplification part of the entire system.
5. Hydraulic actuator
Usually refers to hydraulic or hydraulic motor, it is the output device of the system, used to drive the load.
6. Detection feedback components
For valve ring control, a detection feedback element needs to be added. It detects the actual value of the controlled quantity or intermediate variable and obtains the feedback signal of the system. The detection elements include displacement sensors, tachogenerators, etc. The detection element is often a signal converter (for example-electricity, machine-liquid conversion) to meet the requirements of comparison. The detection element is divided into inner ring and outer ring. The inner ring detection element is usually included in the proportional valve to improve the dynamic and static characteristics of the proportional valve. The outer loop detection element directly detects the output of the input method, which is used to improve the performance and control accuracy of the entire system.

The main advantages of electro-hydraulic proportional control are:
1. Convenient operation and easy to realize remote control;
2. High degree of automation, easy to realize programming control;
3. Stable work and high control accuracy;
4. The structure is simple, the components used are small, and it is not sensitive to pollution;
5. The energy saving effect of the system is good.
The main disadvantages of electro-hydraulic proportional control are higher cost and more complicated technology.