Pneumatic transmission and control technology, abbreviated as pneumatic, is a technology that uses compressed air as the working medium to transmit energy and signals, and realizes various production processes and automatic control. It is an important component of the discipline of fluid transmission and control. In recent decades, pneumatic transmission technology has been widely applied in the automation and labor-saving of industrial industries, playing an extremely important role in promoting the development of automation.

Pneumatic has many advantages in practical applications. 1. Easy to use

As a working medium, air can be found everywhere and comes from a convenient source. After use, it can be directly discharged into the atmosphere without polluting the environment, and there is little or no need to install return air pipelines.

2. Convenient system assembly

The use of quick connectors allows for easy piping, making system assembly, maintenance, and component replacement relatively simple.

3. Good speed

The action is quick and responsive, and can achieve the required pressure and speed in a relatively short period of time. Under certain overload conditions, the system can also ensure safe operation and is less prone to overheating.

4. Safe and reliable

Compressed air will not explode or catch fire, and expensive explosion-proof facilities are not required for use in flammable and explosive places. It can be safely and reliably applied in harsh environments such as flammable, explosive, dusty, radiation, strong magnetism, vibration, and impact.

5. Convenient storage

The air pressure has a high self-sustaining ability, and compressed air can be stored in storage tanks for easy access. Even if the compressor stops running and the air valve closes, the pneumatic system can still maintain a stable pressure. Therefore, continuous operation of the compressor is not required.

6. Can be transmitted over long distances

Due to the low viscosity and flow resistance of air, the pressure loss along the air flow in pipelines is small, which is conducive to centralized supply of media and long-distance transportation. Air, regardless of its distance, is easily transported by pipelines.

7. Overload protection

Pneumatic mechanisms and working components can be overloaded and stop moving, so there is no risk of overload.

8. Cleaning

Basically pollution-free, it is extremely important for occasions that require high purification and pollution-free, such as food, printing, wood, and textile industries. Pneumatic has unique adaptability and is superior to hydraulic, electronic, and electrical control.

The classification of pneumatic components - cylinders. As one of the pneumatic components, there are many classification methods for cylinders. According to the way compressed air exerts force on the piston, it can be divided into single acting cylinder and double acting cylinder; According to the structural characteristics of cylinders, they can be divided into piston type, plunger type, and diaphragm type. According to the functions of cylinders, they can be divided into dozens of types, including ordinary cylinders, thin film cylinders, impact cylinders, gas-liquid damping cylinders, gas-liquid boosting cylinders, digital cylinders, servo cylinders, buffer cylinders, swing cylinders, heat-resistant cylinders, corrosion-resistant cylinders, low friction cylinders, high-speed cylinders, linear drive single element cylinders, modular drive installation cylinders, and pneumatic robotic arm cylinders. Here, the 100 Weier Education editor will introduce single acting cylinders and double acting cylinders in conjunction with the 100 Weier Education "Pneumatic Technology" course and its three-dimensional interactive resources.

A double acting cylinder is generally composed of parts such as a cylinder barrel, front cylinder head, rear cylinder head, piston, piston rod, seal, and fastener. The cylinder barrel is fastened and locked with four screws between the front and rear cylinder heads. There is a piston connected to the piston rod in the cylinder, which is equipped with a piston sealing ring. To prevent air leakage and external dust intrusion, the front cylinder head is equipped with piston rod sealing rings and dust sealing rings. This double acting cylinder is divided into two chambers by the piston: a rod chamber (referred to as the head chamber or front chamber) and a rodless chamber (referred to as the tail chamber or rear chamber). A chamber with a piston rod is called a rod chamber, and a chamber without a piston rod is called a rodless chamber.

When compressed air is input from the air port at the end of the rodless chamber, if the force of the air pressure acting on the left end face of the piston overcomes various reaction forces such as frictional force and load, then when the piston moves forward, the air in the rodless chamber is discharged through the air port at that end, causing the piston rod to extend. Similarly, when compressed air is input into the end port of the rod cavity, the piston rod retracts to its initial position. By alternating intake and exhaust between rodless and rod-shaped chambers, the piston rod extends and retracts, and the cylinder achieves reciprocating linear motion.

A cylinder without a buffer device on the cylinder head is called an unbuffered cylinder, while a cylinder with a buffer device on the cylinder head is called a buffer cylinder. The buffer device consists of a buffer throttle valve, a buffer plunger, and a buffer sealing ring. When the cylinder stroke approaches the end, the buffering device can prevent the phenomenon of high-speed piston hitting the cylinder head from occurring.

A single acting cylinder injects compressed air into the air port at one end of the cylinder head to extend (or retract) the piston rod, while the other end relies on spring force, self weight, or other external forces to restore the piston rod to its initial position. A single acting cylinder only requires compressed air in the direction of action, so it can save half of the compressed air. Mainly used in operations such as clamping, material returning, blocking, pressing, lifting, and feeding.

According to the position of the reset spring, the working cylinders are divided into pre retracted cylinders and pre extended cylinders. When the spring is installed in the rod chamber, the initial position of the cylinder piston rod is in the retracted position due to the force of the spring, and we call this type of cylinder a pre retracted monocycle

Using a cylinder; When the spring is installed in the rodless chamber, the cylinder with the initial position of the piston rod in the extended position is called a pre extended cylinder.

This type of cylinder is equipped with a reset spring on the piston rod side and a breathing port is opened on the front cylinder head. In addition, its structure is basically the same as that of a double acting cylinder. The cylinder barrel and front and rear cylinder heads are fixed by rolling riveting. The stroke of a single acting cylinder is affected by the length of the internal return spring, and its stroke length is generally within 100mm.