Detailed explanation of the function and structure principle of automobile pneumatic butterfly valve
In the automobile suspension, the pneumatic butterfly valve is always used in conjunction with the spring. When we press down a corner of the body, it is the spring that tightens in practice, and the corresponding swing arm swings. When the vehicle is released, the body will bounce back under the spring force. At this time, the pneumatic butterfly valve plays a damping role on the spring bounce, that is, it tends to be stable after bounce. If there is no pneumatic butterfly valve, the spring will be tightened again after rebounding, which means that the body tends to be stable after repeated rebounds. So the pneumatic butterfly valve is used to damp and shock the spring of the automobile suspension when it rebounds.
The hydraulic pneumatic butterfly valve for automobiles is filled with special oil for pneumatic butterfly valve. The internal part is composed of two cylinders: storage cylinder and working cylinder. The piston divides the working cylinder into upper chamber and lower chamber. A stretching valve and a flow valve are arranged on the piston to control the movement of oil between the upper cavity and the lower cavity; The tightening valve and compensation valve between the lower chamber of the working cylinder and the oil storage cylinder are used for the movement of oil between the lower chamber and the oil storage cylinder.
When the pneumatic butterfly valve is tightened, the piston goes down, the volume of the upper chamber increases, and the volume of the lower chamber decreases. The flow valve opens, and the oil in the lower chamber enters the upper chamber through the flow valve; At the same time, a part of the oil flows into the oil storage cylinder by turning over the tightening valve. The throttling effect of these two valves on the oil makes the pneumatic butterfly valve have a damping effect during the contraction movement.
When the pneumatic butterfly valve is extended, the piston goes up, the volume of the upper chamber decreases and the volume of the lower chamber increases, the stretching valve opens, and the oil in the upper chamber enters the lower chamber through the stretching valve; At the same time, a part of the oil turns over for compensation and enters the lower chamber from the oil storage cylinder. The throttling effect of these two valves on the oil makes the pneumatic butterfly valve have a damping effect when it stretches.
Since the spring force of the stretching valve is greater than that of the flow valve, and the flow area of the valve hole of the stretching valve is smaller than that of the flow valve, the damping force generated by the stretching stroke of the shock absorber is greater than the damping force generated by the tightening stroke, reaching the request of rapidly reducing the spring shock.

Guidance for selection of stainless steel pneumatic butterfly valve
Guide for selection of stainless steel pneumatic butterfly valve. Most consumer enterprises of stainless steel pneumatic butterfly valves analyze the causes of the failure of the bellows compensator contraction joint, and find that the failure during operation is mainly manifested in two ways: corrosion leakage and instability deformation, of which corrosion failure is the majority. From the dissection of corrosion failure bellows, it is found that corrosion failure is usually divided into pitting corrosion perforation and stress corrosion cracking, of which chloride ion stress corrosion cracking accounts for about 95% of the total corrosion failure. Therefore, correct selection of bellows manufacturing data and structure, reasonable design of waveform parameters and fatigue life, assurance of device quality and other measures can greatly improve the safety and reliability of bellows compensator contraction joints.
In design, the stability of stainless steel pneumatic butterfly valve should be considered to prevent the instability of bellows. The material shows that the compensation amount of bellows depends on its fatigue life. The higher the fatigue life, the smaller the single wave compensation amount of bellows. In order to reduce the cost and improve the single wave compensation, the lower the allowable fatigue life, the greater the longitudinal bending stress of the bellows caused by displacement, and the higher the comprehensive stress, which greatly reduces the stability of the bellows. When the allowable service life of the bellows design is low, not only the meridian comprehensive stress is high, but also the circumferential stress is relatively high, which makes the bellows enter plastic deformation quickly, leading to the instability of the bellows and causing failure.
The stainless steel pneumatic butterfly valve is widely used in many industries. In addition to considering good compensation ability, reliability is the key to the bellows compensator contraction joint. However, the reliability is guaranteed through multiple links such as design and manufacturing, and the neglect of any link will lead to the reduction of the life of the compensator and even failure.
In addition to design, the data selection of stainless steel pneumatic butterfly valve is also quite critical. For the selection of materials used for bellows, in addition to the working medium, working temperature and external environment, the possibility of stress corrosion, the impact of water treatment agent and pipeline cleaning agent on the data, etc. should also be considered, and on this basis, the welding and forming of bellows data, as well as the performance cost ratio of the data should be separated, so as to select the applicable bellows manufacturing data that meet the working conditions.