Working principle of piston solenoid valve, advantages and control methods of piston solenoid valve

Working principle of piston solenoid valve Piston solenoid valve is a switching fluid control component that relies on the electromagnetic coil to generate electromagnetic force to drive the valve. It is one of the actuators commonly used in pipeline control processes. According to the principle, they are divided into three categories: direct-acting type, step-by-step direct-acting type, and pilot type. The piston solenoid valve is a step-action direct pilot solenoid valve. According to the different open and closed states when the power is cut off, it is mainly divided into normally closed solenoid valves and normally open solenoid valves. The working principle of the piston type normally closed solenoid valve. After the coil is energized, the armature first drives the valve plug of the auxiliary valve to lift under the action of the electromagnetic force. The fluid on the main valve cup flows through the auxiliary valve, reducing the force acting on the main valve. When the pressure on the main valve cup is reduced to a certain value, the armature drives the main valve cup and uses the pressure difference to open the main valve cup and allow the medium to flow. After the coil is powered off, the electromagnetic force disappears and the armature falls back due to its own weight. At the same time, relying on the medium pressure, the main and auxiliary valves can be tightly closed. The working principle of the piston type normally open solenoid valve. After the coil is energized, due to the suction effect, the moving iron core moves down, pressing down the valve plug of the auxiliary valve, closing the auxiliary valve, and the pressure in the main valve cup rises. When the pressure rises When it reaches a certain value, the upper and lower pressure differences of the main valve cup are the same. Due to the action of electromagnetic force, the moving iron core loses its position under the main valve cup, compresses the main valve seat, and the valve closes. When the coil is powered off, the electromagnetic attraction is zero, the auxiliary valve plug and iron core are lifted upward due to the action of the spring, the auxiliary valve opens, and the fluid on the main valve cup flows through the auxiliary valve, reducing the force acting on the main valve. When the pressure on the valve cup is reduced to a certain value, the pressure difference is used to push up the main valve cup, and the main valve opens and the medium flows. Piston solenoid valve control method Normally closed: When the coil is energized, the solenoid core is attracted, the pressure relief hole is opened, the main piston medium pressure pushes, the main valve port is opened, and the medium flows. When the coil is powered off, the main valve is closed and the medium is cut off. Normally open: When the coil is energized, the electromagnet core is attracted, the pressure relief hole is closed, the main piston is pushed by the medium pressure, the main valve is closed, and the medium is cut off. When the coil is powered off, the main valve opens and the medium flows. 1. The pilot-operated piston solenoid valve requires that the medium passing through the solenoid valve must have pressure. If there is no pressure, this type of valve is not suitable. Our solenoid valve here must ensure that the medium has normal pressure in order to work properly. 2. There are two sources of force for opening the main piston of the pilot piston solenoid valve. One is the magnetic force generated after power is applied, and the other is the pressure push of the medium. These two forces must exist at the same time to ensure the normal operation of the pilot piston solenoid valve. Advantages of piston solenoid valve: 1. The solenoid valve core is made of stainless steel and has a piston structure, which has strong resistance to action fatigue. 2. The design structure of the piston ring is more scientific. It is made of special materials and will not be stuck by impurities in the medium. It has high action sealing performance and long service life. 3. The metal piston and the metal valve cavity do not produce direct friction and will not be stuck. The installation direction of the valve body is unlimited. 4. Customized coil, the coil is not easy to burn out. 5. Reasonable sealing materials and structures provide better sealing performance. 6. After restarting after a long-term stop, the action will be equally sensitive. 7. The interface size is usually national or international standards, and customers can customize special interfaces.