Operating Principle of Electrical Proportional Valve
The electrical proportional valve adjusts the cross-sectional area of the valve spool according to the magnitude of the control signal, thereby achieving the technological goal and requirement of adjusting the pressure.
The control of flow by the electrical proportional valve can be divided into two types. One is on-off control, and the other is continuous control. Different from other valves, the servo valve has greater energy loss because it requires a certain amount of flow to maintain the work of the pre-stage control oil circuit. One is on-off control: either fully open or fully closed, the flow is either the maximum or the minimum, with no intermediate state, such as ordinary direct-acting solenoid valves, electromagnetic directional valves, and electro-hydraulic directional valves.
The other is continuous control: the valve port can be opened to any opening degree as needed, thereby controlling the magnitude of the passing flow. There are such valves with manual control, such as throttle valves, and also electrically controlled ones, such as proportional valves and servo valves. The electrical proportional valve can control the gas pressure through electrical signals, enabling continuous and stepless adjustment of the gas pressure, and can realize remote control and program control. It is especially suitable for electrical proportional valves in occasions where continuous or stepless adjustment of gas pressure is required.
Its electronically controlled pressure regulating device is composed of the intake and exhaust adjustment on-off solenoid valves, pressure detection sensor, and control circuit. When there is an input signal, the intake solenoid valve opens, the exhaust solenoid valve closes, the main valve supplies gas to the pilot chamber, the main valve spool moves downwards, and the secondary pressure is output.
At the same time, the secondary pressure value is detected by the pressure sensor and fed back to the control circuit. Based on the deviation between the input signal and the output secondary pressure, the control circuit drives the intake and exhaust solenoid valves with the PWM control method to adjust the pressure in the pilot chamber until the deviation is zero, both the intake and exhaust solenoid valves are closed, and the main valve spool reaches equilibrium at a new position, thereby obtaining an output pressure proportional to the input signal.
The electrical proportional valve, which is easily and quickly selectable and included in the automation of EasyU, has developed and produced plug-in proportional valves and proportional multi-way valves fully considering the characteristics of construction machinery use, with functions such as pilot control, load sensing, and pressure compensation. Its appearance is of great significance for the overall improvement of the technical level of mobile hydraulic machinery. Especially in aspects such as electrically controlled pilot operation, wireless remote control, and wired remote control, it shows good application prospects.
As a traditional pneumatic and flow control component, the electrical proportional valve can be divided into three types: servo valve, proportional valve, and adjustment on-off solenoid valve. These valves have different characteristics when applied to the control of pressure and flow, and the pressure control accuracy and stability are also different.
And the electrical proportional valve of the on-off solenoid valve type can achieve very high control accuracy because it uses the adjustment on-off solenoid valve and PWM pulse modulation in the control.
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Shenyang HOlian Precision instrument co.,Ltd founded in 2017,is specialized production of oxygen generator accessories :Miniature solenoid valve for Portable Medical oxygen generator,4 Way 2 position Medical oxygen generator,3L to 10L Medical Oxygen Generator Solenoid Valve,pressure regulator assembly for oxygen concentrator,Pressure reducing Assembly for oxygen concentrator,Pinhole flowmeter of oxygen concentraror,Pinhole flowmeter of Medical oxygen concentrator,5L flowmeter for oxygen concentrator,Special firesafe Valve for oxygen concentrator,Firesafe Cannula Valve Oxygen Supply Tubing Connector,Oxygen primary filter,Medical Grade Filter,Check valve (material PA6),Check valve (material ABS),Oxygen generator accessories Molecular sieve tank head,Oxygen Concentrator Accessories Air Filters,Oxygen Concentrator Accessories NPT1/8-∅8 Connector,Oxygen Concentrator Accessories NPT1/8-∅10 Connector,Oxygen Concentrator Accessories 3 way Nozzle,Oxygen Concentrator Accessories 90° Nozzle,Mold manufacturing and i jection molding.