Features of electrical proportional valves, what is proportional valves

1) The pressure and speed can be adjusted infinitely, and the impact phenomenon of the constant on/off valve is avoided.

2) It can realize remote control and program control.

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

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

5) The use of power is small, the heat is less, and the noise is low.

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

If it is domestic, it is recommended that the NNT electric proportional valve, which optimizes and improves the sensitivity, is compact and lightweight, and can realize continuous and stepless regulation of air pressure, and can realize remote control and program control.

Introduction to Electrical Proportional Valves:

The NNT electrical proportional valve adjusts the cross-sectional area of the valve core according to the size of the control signal. So as to achieve the process objectives and requirements of adjusting the pressure magnitude. The control of the flow rate by the electrical proportional valve can be divided into two types.

One is on-off control, the other is continuous control, servo valve is different from other valves, its energy loss is greater, because it requires a certain flow rate to maintain the work of the pre-stage control oil circuit. One is switch control: either fully open or fully closed, the flow rate is either maximum or small, and there is no intermediate state, such as ordinary solenoid straight-through valves, solenoid reversing valves, and electro-hydraulic reversing valves.

The other is continuous control: the valve port can be opened any opening according to the need, so as to control the size of the flow rate, this kind of valve has manual control, such as throttle valve, and also has electronic control, such as proportional valve, servo valve. The electric proportional valve controls the air pressure through the electrical signal, which can realize the continuous and stepless adjustment of the air pressure, and can realize remote control and program control.

Advantages of electrical proportional valves:

1) Electrical proportional mode, to achieve stepless control of outlet pressure.

2) It can realize remote control and program control.

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

4) Compared with hydraulic proportional valves, it is small in size, light in weight, compact in structure, lightweight and low in cost, but the response speed is much slower than that of hydraulic system, and it is also more sensitive to load changes.

5) Low power consumption: less than 4W (communication form).

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

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The proportional valve is a new type of hydraulic control device.

The proportional valve is to replace the original control part with a proportional solenoid on the ordinary pressure valve, flow valve and directional valve, and control the pressure, flow or direction of the oil flow continuously and proportionally according to the input electrical signal.

Proportional valves are generally pressure-compensated, and the output pressure and flow can be unaffected by load changes. The proportional valve is developed by some original electro-hydraulic servo valve manufacturers on the basis of electro-hydraulic servo valve and reducing the design and manufacturing accuracy.

How proportional valves work::

When the command signal is amplified by the proportional amplifier, and the proportional output current is given to the proportional solenoid of the proportional valve, the proportional solenoid outputs the force and moves the position of the valve core proportionally, the flow of the liquid flow can be proportionally controlled and the direction of the liquid flow can be changed, so as to realize the position or speed control of the actuator.

In some applications that require high position or speed accuracy, a closed-loop control system can also be formed by detecting the displacement or speed of the actuator.

The proportional valve is composed of two parts: a DC proportional solenoid and a hydraulic valve. The core of proportional valve to achieve continuous control is the use of proportional solenoids, there are many types of proportional solenoids, but the working principle is basically the same, they are all developed according to the control needs of proportional valves.

How to adjust the pressure of the electric proportional valve; 1. First of all, the pressure, the flow value reaches the maximum to see if the pressure gauge has no action and whether there is a bottom pressure, if there is a pressure valve, please adjust the pressure valve, and then adjust the flow value to 0 to start any action whether there is action, if there is no action to adjust the flow valve. The above conditions must be the minimum current of 200mA and the maximum current of the pressure flow rate, and then adjust the total pressure valve pressure value to kilograms. The valve's control of the flow can be divided into two types:

One is switch control: either fully open or fully closed, the flow is either maximum or small, and there is no intermediate state, such as ordinary solenoid straight-through valves, electromagnetic reversing valves, and electro-hydraulic reversing valves. The other is continuous control:

The valve port can be opened according to the needs of any rotten reed opening, so as to control the size of the flow rate of the hungry belt, this kind of valve has manual control, such as throttle valve, there are also electronic control, such as proportional valve, servo valve.

First, the characteristics of the two are different:

1. The characteristics of proportional valves: the electrical signal is easy to transmit, and the long-distance control can be easily realized; It can continuously control the pressure and flow rate of the hydraulic system according to the ratio bucket, realize the control of the position, speed and force of the actuator, and can reduce the impact when the pressure is transformed; The number of components is reduced and the oil circuit is simplified.

2. The characteristics of ordinary valves (i.e., ordinary hydraulic valves) are: flexible action, reliable action, small impact and vibration during work, low noise, and long service life; When the fluid passes through the hydraulic valve, the pressure loss is small; When the valve port is closed, the sealing performance is good, the internal leakage is small, and there is no external leakage; The controlled parameters (pressure or flow rate) are stable and vary little when subjected to external disturbances.

Second, the use of the two is different:

1. The use of proportional valve: proportional valve is composed of two parts: DC proportional solenoid and hydraulic valve, the core of proportional valve to achieve continuous control is the use of proportional solenoid, there are many kinds of proportional solenoids, but the working principle is basically the same, they are developed according to the control needs of proportional valves.

2. The use of ordinary valve pins: controlled by the pressure oil of the pressure distribution valve, it is usually used in combination with the electromagnetic pressure distribution valve, which can be used to remotely control the on-off of the oil, gas and water pipeline system of the hydropower station. It is often used in clamping, control, lubrication and other oil circuits.

Third, the classification of the two is different:

1. Classification of proportional valves:

1) Solenoid proportional valve: Solenoid refers to the proportional valve that uses the proportional electromagnet as an electrical mechanical conversion element, and the proportional solenoid converts the input current signal into force, displacement mechanical signal output and then controls the pressure, flow and direction and other parameters.

2) electric proportional valve: electric type refers to the use of DC servo electric potato ruler motor as an electrical mechanical conversion element of the proportional valve, DC servo motor will input electrical signal into rotary motion speed, and then through the screw nut, rack and pinion or gear cam and other deceleration devices and conversion mechanisms, output force and displacement, further control hydraulic parameters.

3) Electro-hydraulic proportional valve: Electro-hydraulic refers to the proportional valve with the structure of torque motor and nozzle baffle as the pilot control level. Input different electrical signals to the torque motor, and output displacement or angular displacement through the baffle connected with it (sometimes the armature of the torque motor is the baffle), change the distance between the baffle and the nozzle, change the oil flow resistance of the nozzle, and then control the transmission parameters.

2. Classification of ordinary valves:

1) Classified according to control method: manual, electronically controlled, and hydraulic-controlled.

2) Classification by function: flow valve (throttle valve, speed control valve, diversion collector valve), pressure valve (relief valve, pressure reducing valve, sequential valve, relief valve), directional valve (electromagnetic reversing valve, manual reversing valve, check valve, hydraulic control check valve).

3) According to the installation method: plate valve, pipe valve, superimposed valve, threaded cartridge valve, cover valve.

4) According to the operation mode: manual valve, motorized valve, electric valve, hydraulic valve, electro-hydraulic valve, etc.

What is the specific content of the principle and classification of proportional valves, and the following Zhongda Consulting will answer for you.

Proportional control valves are mainly used for openloopcontrol. The output of the proportional control valve is proportional to the input signal, and the magnetic force generated by the solenoid coil in the proportional control valve is proportional to the current.

In the traditional type of hydraulic control valve, only the hydraulic pressure can be controlled at a fixed value, for example: the pressure valve actuates at a certain set pressure, the flow valve keeps passing through the set flow rate, and the directional valve switches the direction of the liquid flow. As a result, the functionality of the system composed of these control valves is somewhat limited, and with the advancement of technology, many hydraulic systems require the flow and pressure to change continuously or proportionally with the change of the input signal of the control valve.

Although the hydraulic servo system can meet its requirements, and the accuracy is very high and closed, but for most of the industry, they do not require the system to have such a high quality, but hope to ensure a certain control performance under the condition of low cost, reliable work, simple maintenance, so the proportional control valve is developed in this context.

Proportional control valves can be divided into three categories: pressure control valves, flow control valves and directional control valves.

Pressure control valve: The manual adjustment device that replaces the guided relief valve with a proportional solenoid valve becomes a guided proportional relief valve, and its output hydraulic pressure is continuously or proportionally controlled by the input signal.

Flow control valve: The manual adjustment device of the throttle valve or the speed control valve is replaced by a proportional solenoid valve, and the throttle opening of the throttle valve or the speed control valve is controlled by an input signal, and the output flow rate can be controlled continuously or proportionally. Therefore, the opening of the throttle can be determined by the voltage of the input signal.

Directional control valve: the proportional solenoid valve replaces the general solenoid valve of the directional valve to form a direct-acting proportional directional valve, the sliding shaft can not only be transposed, but also the transposition of the stroke can be continuously or proportionally branched and changed, so that the oil area between the connecting oil ports can also be continuously or proportionally changed, so the proportional directional control valve can not only control the direction of movement of the actuator, but also control its speed.

The electropneumatic proportional control valve uses an electric proportional signal to manipulate the packing box to keep the flow or pressure at a set level, so it is an important component to control the flow or pressure system, which effectively ensures the adjustable flow and pressure of the intermediate link, so as to ensure the stability of the flow of the whole system. Electropneumatic proportional control valve adjustment is a more detailed work, in order to ensure the quality of adjustment, some basic operating procedures are required, the following is an introduction to the adjustment method of the electropneumatic proportional control valve: 1

Preparation: first prepare the control instruments and accessories for grinding branches and bends according to the relevant specifications, and then calibrate the range of measurement signals and output signals of each part of the instrument and controller of the system according to the maintenance requirements, and the correlation between the pressure and flow rate to ensure the measurement accuracy 2Control Adjustments:

According to the parameters displayed by the measuring instrument, open the positioning knob of the regulating valve, determine the positioning angle of the valve, make the regulating system accurately control the flow or pressure of the medium, open the process knob of the regulating valve at the same time, adjust to the expected flow or pressure according to the actual needs, and close the regulating process knob 3 when the set flow rate is reachedInstallation: After installing the control valve, first debug and check whether there are obvious changes, such as blind and boring fruit can not meet the actual work requirements, it should be modified in time until the requirements are met4

Finishing touches: check the reliability of the system equipment, ensure the normal operation of the system, check whether the matching and wiring of the individual components are correct, ensure the integrity of the connected sensors and transmitted signals.