Vacuum solenoid valve working principle diagram, vacuum solenoid valve structure and common problems

Vacuum solenoid valve working principle diagram Vacuum solenoid valve controls opening and closing through AC or DC power supply. It can use the electromagnetic principle to realize vacuum treatment of pipelines. It is mainly used in vacuum pipelines or linkage control systems with vacuum pumps. It is directly operated by an electromagnet, controls the opening and closing of the valve, opens the atmosphere, and is used to fill the vacuum container with atmosphere, thereby achieving automatic control or remote control. At the same time, electromagnetic control can have a greater impact on the entire working status of the pipeline system, and the use of solenoid valves can also effectively avoid the impact of other irrelevant factors on the pipeline, thereby making correct decisions on the working status of the pipeline system. Adjustment. When the vacuum solenoid valve is installed on a mechanical vacuum pump, the valve and the pump are connected to the same power supply, and the opening and stopping of the pump directly controls the opening and closing of the valve. When the pump stops working or the power supply is suddenly interrupted, the valve can automatically close the vacuum system and fill the pump cavity with atmospheric air through the air inlet of the pump to prevent the backflow of pump oil from contaminating the vacuum system. 1. In the non-energized state (shown in the left picture above): Under the action of rubber membrane I and vacuum pressure, the armature moves upward to a high position, and rubber membrane II is pushed downward by needle 1. At this time, the controlled The object (EGR valve vacuum chamber) is connected to the atmosphere, and the air flow direction is as shown by the green line in the left picture. The vacuum path is blocked, and the controlled object (EGR valve) does not act (EGR valve is closed). 2. In the energized state (shown in the right picture of the above figure): Under the action of the magnetic field force, the armature moves downward to the low position, and the rubber membrane II is pulled downward by the armature. At this time, the controlled object (EGR valve vacuum chamber) and The vacuum source (vacuum pump) is connected, the air flow direction is as shown by the green line in the picture on the right, the air path is blocked, the vacuum path is opened, and the controlled object (EGR valve) starts to act (EGR valve opens). 3. When the operating frequency of the vacuum solenoid valve is 300 Hz, F on the armature of the solenoid valve must move 300 times per second, that is, the air flow in the vacuum path is interrupted 300 times per second. Structural features of the vacuum solenoid valve 1. Since the operating pressure of the vacuum solenoid valve is in a vacuum state, it cannot be started with pressure. Therefore, only direct-acting solenoid valves can be used, while ordinary solenoid valves use pilot-operated solenoid valves when there is a pressure difference. Valve;2. The vacuum solenoid valve has very high leakage requirements, so the sealing method cannot use gap sealing, and the high degree of sealing of the connection should be ensured. 3. The air flow sequence of the vacuum solenoid valve is reverse flow state. 4. The valve body is generally made of stainless steel, but there is no requirement for the valve body material of ordinary solenoid valves. Common problems and solutions for vacuum solenoid valves 1. Airflow noise From the above working principle, it can be seen that when the state (vacuum degree) of the controlled object (EGR valve vacuum chamber) needs to change greatly, then the instantaneous entry through the air filter The amount of air is large, and air flow noise will be generated during the air entry process. Therefore, this noise is an inherent characteristic of the operation of this type of vacuum solenoid valve and cannot be eliminated. However, if the processing accuracy of the moving parts is high and the assembly accuracy is improved, the air flow will Noise can be reduced. 2. The moving part (armature) is stuck ①. The armature is stuck at the upper end: When the armature is stuck at the upper end, the vacuum chamber of the EGR valve is not connected to the vacuum source (vacuum pump). As shown in the left picture above, the EGR valve is normally closed. EGR valve is not working. ②. The armature is stuck at the lower end: When the armature is stuck at the lower end, the vacuum chamber of the EGR valve is directly connected to the vacuum source (vacuum pump) but not to the atmosphere. As shown in the right picture above, the EGR valve is always open. This will cause the engine to emit black smoke. The above is the working principle diagram of the vacuum solenoid valve, the structure of the vacuum solenoid valve and the introduction of common problems. If you want to know more relevant information, please log in to Sunway Pneumatic www.diancifa.cc to view.