Future trends in the development of electromechanical products such as valves
With the continuous improvement of production automation, the application of pneumatic technology has rapidly expanded, and the variety and specifications of pneumatic products have continued to increase. The performance and quality have continued to increase, and the market sales value has grown steadily. The development trend of pneumatic products is mainly in the following aspects:
First, miniaturization and integration
The limited space requires the size of the aerodynamic components to be as small as possible, and miniaturization is the main trend. Now the minimum cylinder bore diameter is only f2.5, and the switch is formulated; the solenoid valve width is only 10mm, the effective cross-sectional area is 5mm2; the pressure reducing valve of interface f4 has also been developed. According to the survey, the demand for miniaturized components is doubled approximately every five years.
The integration of gas valves not only integrates several valves, but also the reliability of maintenance and work.
Second, composition, intelligence
The simplest combination of components is a valved, switched cylinder. In material handling, a combination of cylinders, swing cylinders, pneumatic chucks, and vacuum chucks has been used; there is also a combination of moving small items that combine two cylinders with guides in X and Y axes, respectively Made of, also equipped with solenoid valve, program controller, compact structure, small footprint, adjustable stroke.
In order to make the positioning of the cylinder more accurate, sensors, proportional valves, etc. are used to achieve feedback control, positioning accuracy of 0.01mm.
In terms of cylinder precision, 0.3mm/s low-speed cylinders and 0.01N micro-load cylinders have also been developed. In the air source treatment, a filter with a filtration accuracy of 0.01 mm, a filtration efficiency of 99.9999%, and a pressure reducing valve with a sensitivity of 0.001 MPa have been developed.
Fourth, high speed
In order to increase productivity, the pace of automation is accelerating, and high speed is an inevitable trend.
At present, the cylinder piston speed range is 50-750mm/s. The piston speed of the cylinder is required to increase to 5m/s and up to 10m/s. According to the survey, five years later, at a speed of 2-5 m/s, the demand for cylinders will increase by 2.5 times, and the demand for cylinders above 5 m/s will increase by three times. Corresponding to this, the response speed of the valve will be accelerated, requiring the current 1/100 second to be increased to 1/1000 second.
Fifth, no oil, tasteless, sterilized
Humans are increasingly demanding of the environment, so non-oil-lubricated pneumatic components will be popularized. There are also some special industries such as food, beverages, pharmaceuticals, electronics, etc. The requirements for air are more stringent, and in addition to no oil, odorless, sterile, etc. are required, and such filters with special requirements will be continuously developed.
Sixth, high life, high reliability and self-diagnosis function
50 million life-span valves and 3000 km cylinders have been commercialized, but there is a high-frequency valve life expectancy of more than 100 million times, preferably 200 million times, on textile machinery. This requirement, the existing elastic sealing valve is difficult to achieve, which makes the gap sealing element regained importance. U.S. Numatics has an air valve that uses a gap seal. After venting, the valve core is suspended in the valve body to form a frictionless motion. It also has a self-dust control function, and the valve life can exceed 200 million times. Although it is an old product, it is worth learning from. Pneumatic components are mostly used in automatic production lines. Failure of components often affects the operation of the entire line. Sudden stopping of the production line causes serious losses. For this reason, high requirements are placed on the operational reliability of pneumatic components. The pneumatic components requested by a certain chemical fiber company in Jiangsu are absolutely reliable within the set life, and they can be replaced when they expire. Here, the balance of life of various types of components has also been proposed, namely the so-called equal-life design. Sometimes, in order to ensure reliable work, the life index has to be sacrificed. Therefore, the self-diagnostic function of the pneumatic system is mentioned on the agenda, and components and systems for self-diagnosis functions such as additional predictive life are being developed. With the multifunctionalization of mechanical devices, the number of wiring increases, which not only increases the workload of installation and maintenance, but also prone to failures and affects the reliability of work. Therefore, the improvement of the wiring system is also for pneumatic components and system designers. Pay attention.
Seven, energy saving, low power consumption
Energy conservation is a permanent issue for enterprises and will be stipulated in the establishment of the ISO14000 environmental protection system standard.
The low power consumption of pneumatic components is not only for energy saving, but more importantly it can be combined with microelectronics technology. The 0.5W power solenoid valve has long been commercialized, and 0.4W and 0.3W air valves have also been developed and can be directly controlled by the PC.
Eight, mechanical and electrical integration
In order to accurately achieve preset control objectives (such as switching, speed, output force, position, etc.), a closed loop feedback control method should be used. The conversion between gas and electrical signals becomes the key to achieving closed-loop control, and the proportional control valve can be the interface for this conversion. The development of various types of proportional control valves and electro-pneumatic proportional/servo systems for a considerable period of time in the future, and their performance, reliability, and low price are major issues in the development of pneumatic technologies.
There are already many examples of proportional/servo system applications, such as precise positioning of cylinders; suspension systems for vehicles to achieve good vibration damping performance; automatic tilting of the device when the cable car turns; robots that serve the patient. How to make the above examples more practical and economical needs further improvement.
Nine, meet the special requirements of certain industries
In the fierce market competition, the development of dedicated pneumatic components for the specific requirements of certain industries is an important aspect of market development, and all plants are very concerned. Recent developments in the domestic pneumatic industry such as aluminum cylinders (high temperature, self-locking), special cylinders for railways (seismic, high reliability), rail valves for lubrication (low temperature resistance, self-filtering capability), environmentally-friendly automotive gas systems ( Multi-media, excellent performance, etc.
Ten, application of new technologies, new processes, new materials
Techniques such as profile extrusion, casting impregnation and module assembly have been widely used in China more than ten years ago; new die-casting technologies (hydraulic core-pulling, vacuum die-casting, etc.) and deburring (explosives, electrolysis, etc.) are already in use in China. Progressive promotion; piezoelectric technology, bus technology, new soft magnetic materials, diafiltration membranes, etc. are being applied; superfinishing and nanotechnology will also be transplanted.
The scientific and technical personnel in the pneumatics industry are particularly concerned about the new developments in the development of seals. Once the seals of new structures and new materials emerge, they will be adopted.
The implementation of standards, especially ISO international standards, is a principle that companies must follow. It has two aspects to be done: The first is that pneumatic products should implement current standards related to aerodynamics, such as terms, technical parameters, test methods, installation dimensions, and safety indicators. The second is that enterprises must establish a guarantee system as stipulated by the standards, and there are three: quality (ISO9000), environmental protection (ISO14000) and safety (ISO18000). Standards are constantly being added and revised, and companies and their products will continue to develop and update accordingly. Only in this way can pneumatic technology be promoted to develop steadily.
From the recent promulgation of ISO international standards for pneumatics, the safety requirements for pneumatic components and systems are very strict. ISO4414 pneumatics classifies the hazardous elements into 14 categories, mainly including mechanical strength, electrical appliances, noise, and control failures. ISO International also promulgated the ISO18000 standard, requiring companies to establish a security guarantee system and put safety issues on a particularly important agenda. For this reason, product development and system design that actually consider safety indicators are also the general trend in the development of pneumatic technologies. For domestic companies, since past industry standards have neglected safety issues, it is necessary to reassess and correct products that have already been put on the market.
Commonly used metal materials in foreign brands comparison table