The expansion of the application of pneumatic technology is a sign of the development of the pneumatic industry. The application of pneumatic components is mainly in two aspects: maintenance and matching. In the past, the sales of domestic pneumatic components were used for maintenance, and the sales share of the main supporting components increased year by year. The application of domestic pneumatic components ranges from metallurgical equipment worth tens of millions of yuan to chairs worth only one to two hundred yuan. Railway switch switches, locomotive wheel and rail lubrication, train brakes, street sweeping, lifting equipment in special workshops, military command vehicles, etc. all use specially developed domestic pneumatic components. This shows that pneumatic technology has "penetrated" into all walks of life and is expanding day by day.
Although my country's pneumatic industry has reached a certain scale and technical level, it is far behind the international advanced level. The output value of pneumatic products in my country only accounts for 1.3% of the world's total output value, which is only 1/21 of the United States, 1/15 of Japan, and 1/8 of Germany. This is not commensurate with a country with a population of more than 1 billion. In terms of varieties, a Japanese company has 6,500 varieties, and our country only has 1/5 of them. The gap between product performance and quality level is also very large.
As pneumatic technology is increasingly used in equipment for automatic assembly and automatic processing of small and special items in various industries, the performance of the original traditional pneumatic components is constantly improving, and new products that meet market requirements are being developed one after another. The variety of pneumatic components is increasing day by day, and its development trends mainly include the following aspects:
Smaller size, lighter weight, lower power consumption. In the manufacturing industries of electronic components, pharmaceuticals, etc., due to the small size of the processed parts, it is bound to limit the size of pneumatic components. Miniaturization and lightness are the first of pneumatic components A development direction. Foreign countries have developed an ultra-small solenoid valve the size of a thumb with an effective cross-sectional area of 0.2mm2. It is more ideal to be able to develop components with small dimensions and large flow rates. For this reason, the flow rate of the valve of the same size has been increased by 2 to 3.3 times. There is a series of small solenoid valves whose body width is only 10mm, and the effective area can reach 5mm2; the width is 15mm, and the effective area can reach 10mm2.
The power consumption of foreign solenoid valves has reached 0.5W, and will be further reduced to adapt to the combination with microelectronics.
Most of the air source treatment assemblies at home and abroad adopt the building block structure, which is not only compact in size, but also convenient for combination and maintenance.
The positioning accuracy of the actuator is improved, the rigidity is increased, the piston rod does not rotate, and it is more convenient to use. In order to improve the positioning accuracy of the cylinder, the application of the cylinder with the brake mechanism and the servo system is more and more common. The cylinder with servo system can still obtain a positioning accuracy of ±0.1mm even if the air supply pressure and the negative load change.
At international exhibitions, there are many cylinders with various special-shaped cross-section cylinders and piston rods. Since the piston rod does not rotate, this type of cylinder can maintain a certain accuracy without additional guides when applied to the host. In addition, many cylinders and cylinder sliding components with various guide mechanisms have been developed, such as cylinders with two guide rods, double-piston rods and double-cylinder cylinders.
The shape of the cylinder barrel is not limited to a round shape, but a square shape, a rice-shaped shape or other shapes. Guide grooves, installation grooves for sensors and switches, etc. are opened on the profile, making it easier for users to install and use.
Multifunctional and compound. In order to facilitate users and meet the needs of the market, various small pneumatic systems composed of multiple pneumatic components and equipped with control devices have been developed. For example, the component used to move small items is composed of two cylinders with guides according to the X axis and Z axis. This component can move 3kg heavy objects, is equipped with solenoid valve, program controller, compact structure, small space occupation, and adjustable stroke. Another example is a loading and unloading module. There are seven modules with different functions, which can complete the loading and unloading operations on a precision assembly line. Different modules can be combined arbitrarily according to the content of the job. There is also a manipulator which is a combination of a swing cylinder and a chuck that has a small shape and can change the swing angle. There are several types of chucks for the chuck.
Combined with electronic technology, a large number of sensors are used, and pneumatic components are intelligent. Cylinders with switches have been widely used in China. The switch volume will be smaller and higher performance. It can be embedded in the cylinder body; some also have a two-color display to show the position error , Make the system more reliable. Using sensors instead of flow meters and pressure gauges can automatically control the flow and pressure of compressed air, which can save energy and ensure the normal operation of the device. Pneumatic servo positioning systems have already entered the market. The system uses a three-position five-way pneumatic servo valve to compare the predetermined positioning target with the detection data of the position sensor, and implement negative feedback control. When the maximum speed of the cylinder reaches 2m/s and the stroke is 300mm, the positioning accuracy of the system is ±0.1mm. Japan successfully trial-produced a new type of intelligent solenoid valve, which is equipped with a logic circuit with a sensor, which is the product of the combination of pneumatic components and optoelectronic technology. It can directly receive the signal from the sensor. When the signal meets the specified conditions, it can complete the action by itself without going through the external controller to achieve the control purpose. It has been applied to the conveyor belt of objects, which can identify the size of the objects to be transported, so that large pieces can be sent directly and small pieces can be diverted.
Higher safety and reliability. From the international standards of pneumatic technology, the standards not only put forward interchangeability requirements, but also emphasize safety.
Many applications of pneumatic components, such as steel rolling mills, textile assembly lines, etc., cannot be interrupted due to quality problems of pneumatic components during working hours, otherwise huge losses will be caused. Therefore, the reliability of pneumatic components is very important. There are a lot of pneumatic components used in marine ships, but there are not many pneumatic component factories that can enter this field. The reason is that their reliability requirements for pneumatic components are particularly high, and they must pass the relevant international machinery certification.
To develop towards high speed, high frequency, high response and long life. In order to improve the production efficiency of production equipment, it is imperative to increase the working speed of the actuator. The working speed of cylinders in our country is generally below 0.5m/s. According to the prediction of Japanese experts, the working speed of most cylinders will increase to 1~2m/s after five years, and some require up to 5m/s. The increase in the working speed of the cylinder requires not only the quality of the cylinder, but also the corresponding improvement in the structure, such as the configuration of hydraulic shock absorbers to increase the cushioning effect. The response time of the solenoid valve will be less than 10ms, and the service life will be increased to more than 50 million times. There is a gap-sealed valve in the United States. Since the valve core is suspended in the valve body and does not touch each other, it has a lifespan of up to 200 million times without lubrication.