Hydraulic and pneumatic technology trends of social demand will always be the driving force to promote technological development, reduce energy consumption, improve efficiency, meet environmental requirements, mechatronics, high reliability of hydraulic pneumatic technology continue to eternal goal, but also hydraulic and pneumatic products compete in the market are the key to victory. In order to meet these goals and to meet the needs of users, the development of modern hydraulic and pneumatic products showed the following main trends.
Hydraulic products technology trends
As the hydraulic technology is widely applied to high-tech achievements, such as automatic control technology, computer technology, microelectronics, friction and wear technology , reliability, technology and new processes and new materials, the traditional techniques with new development, but also to the quality of hydraulic systems and components, there is a certain level of improvement. Nevertheless, to the twenty-first century hydraulic technology can not have amazing technological breakthroughs, it should mainly rely on existing technology to improve and expand, expanding its application areas in order to meet future requirements. And foreign experts, the main trend is expected to focus on the following aspects:
1. Reduce energy consumption, make use of energy
hydraulic technology in the mechanical energy is converted into pressure energy and anti-conversion areas, has made great progress, but there has been energy loss, mainly reflected in the system volume losses and mechanical losses on. If all of the pressure energy can be fully utilized, the energy conversion efficiency of the process would be significantly improved. In order to reduce the loss of pressure energy, the following questions must be addressed:
¢Ù components and systems to reduce internal pressure loss, to reduce power losses. Mainly in the improvement of the internal flow channel component pressure loss, the use of integrated circuits and casting flow channel, pipeline losses can be reduced while also reducing leakage losses.
¢Ú reduce or eliminate system throttling losses, minimizing non-security needs of overflow traffic, avoid using throttle system to regulate the flow and pressure.
¢Û hydrostatic technology, new sealing materials reduce friction losses.
¢Ü development of small, lightweight, composite, extensive development of three diameter, 4-way solenoid valve diameter and low power solenoid valve.
¢Ý improve the hydraulic system performance with load-sensing system, secondary-conditioning systems and the use of accumulator circuits.
Komatsu, Hitachi, Kawasaki, Germany Rexroth, Linde, USA Eiton-Vickers', Parker are using load-sensing system, which can save power 20-30%.
¢Þ for the timely maintenance of the hydraulic system to prevent contamination of the system affect the life and reliability of the need to develop new pollution detection method for online measurement of pollution, to promptly adjust, not lag, so the treatment is not timely and cause losses.
2. Proactive maintenance
hydraulic system maintenance from the past simple failure overhaul, the development of fault prediction that found fault symptom, the pre-maintenance, removal of hidden faults, avoid equipment fatal accidents development.
To implement proactive maintenance techniques must be strengthened hydraulic system fault diagnosis methods of research, currently, with experienced maintenance technicians sense Palace and experience, through seeing, hearing, touch, test Failure to find such judgments are not suitable for modern industry to large-scale, continuous development and modernization of direction, so that the hydraulic system fault diagnosis must modernize, strengthen expert system to summarize the knowledge of experts, establish a complete, expert knowledge with learning function library and use the computer based on the input of the phenomenon and the knowledge base of knowledge, with the inference engine reasoning method exists, leads to calculate the causes, improve maintenance programs and preventive measures. To further lead to the hydraulic system fault diagnosis expert system generic software tools for different hydraulic systems simply modify and change in a small number of rules.
In addition, the hydraulic system should be developed from the compensation system, including self-adjusting, self-lubricating, self-correction, before a failure occurs, compensation into the city, which is the hydraulic industry efforts.
3. Machine electronics and mechatronics
hydraulic drive technology combine to make the traditional hydraulic transmission and control technology to increase the co- dynamic, expanding the application fields. Mechanical and electrical integration can improve operational reliability, the hydraulic system is flexible, intelligent, low efficiency of the hydraulic system change, oil spills, and poor maintenance shortcomings, give full play to contribute to large hydraulic transmission, coherence, fast response, etc., which Major developments are as follows:
(1) the application of electro-hydraulic servo proportional technology will continue to expand. Hydraulic system will be the last on-oE electric hydraulic system and open-loop proportional control system closed loop proportional servo steering system, to adapt to these developments, pressure, flow, location, temperature, velocity, acceleration sensors should be standardized. Computer interface should also achieve unity and compatibility.
(2) develop and direct interface to the computer consumes 5mA these solenoid valves, as well as for high-frequency pulse-width modulation system solenoid valve (less than 3mS) and so on.
(3) hydraulic system flow, pressure, temperature, oil pollution and other values will achieve automatic measurement and diagnosis, reduce the price of the computer, monitoring system, including centralized monitoring and automatic control system will be developed.
(4) computer simulation standardization, especially for precision, "advanced" system is also this request.
(5) directly controlled by the electronic components will be widely used, such as electronic direct control of the hydraulic pump, using a common control mechanism is the future of issues need to be explored, hydraulic products Mechatronics status and development.
hydraulic components will be high-performance, high-quality, high reliability, the system sets direction; towards low power, low noise, vibration, and no leakage pollution control, the application of water-based media, such as the direction of development to adapt to environmental requirements; develop highly integrated high power density, intelligence, mechatronics as well as light and small miniature hydraulic components; actively adopt new technology, new materials and electronics, sensors and other high-tech .
Fluid coupling to high-power and high-speed integrated hydraulic transmission system development, developing water medium speed fluid coupling and to the development of automotive applications, developing liquid force reducer, improve product reliability and mean time between failures; torque converter to develop high-power products, improve parts of the manufacturing process technology, improve reliability, promote computer-aided technology, developed torque converter and supporting the use of technology power shift transmission; viscous clutch governor should improve product quality, the formation of bulk to the high-power and high-speed direction.
products to small size, light weight, low power consumption, the combination of integrated direction, to many kinds of actuators, compact structure, high positioning accuracy Direction development; pneumatic components and electronic technology, the intelligent direction; component performance to high-speed, high-frequency, high-response, high life, high temperature, high pressure direction, generally with no oil lubrication, the application of new technology, new technology and new materials.
1, using high pressure of hydraulic components, continuous working pressure up to 40Mpa, instantaneous maximum pressure reached 48Mpa;
(1) regulation and control forms;
(2 ) to further improve regulation performance, improve powertrain efficiency;
(3) development and mechanical, hydraulic, hybrid electric drive portfolio adjustment gear;
(4) development of energy-saving, energy storage function Efficient system;
(5) to further reduce noise;
(6) Application of screw-in hydraulic cartridge valve technology, compact structure, reduce oil spills.
2, load sensing control technology in international development trends:
(a) the development of system optimization matching technology;
(2) to further improve the system dynamic characteristics, making it both energy efficient, but also more rapid response characteristics;
(3) further mechatronics, developing electro-hydraulic load adjust sensing system;
(4) development of threaded cartridge valve technology to reduce system leakage, meet the special requirements of mobile machinery.
Country in combine harvesters, tractors, forklifts and other mainframe products, has been the application of hydrostatic drive technology development work, but because of the corresponding hydraulic components is not complete, quality tests, System design is unreasonable and other reasons, are unable to commercialization; currently running machinery in the hydrostatic transmission device mainly rely on imports, the application of the load sensing technology, due to the domestic development of the load-sensing hydraulic steering gear, multi-channel valves, load sensing priority valve and variable pump and other key components, so existing domestic pump control and load sensing valve control system products, loaders, forklifts, plastic injection machines and die casting machines are applied, and nearly one thousand units of production capacity. Because of the technology still lacks a comprehensive, in-depth theoretical analysis and experimental research, optimal matching system lacks rationality poor and other reasons, often fail to achieve energy savings and long development cycle and are affected in the host Application. These all need to be improved as soon as possible, as soon as possible so that more domestic hydrostatic transmission and load-sensing adjustment device, operating machinery, etc. to meet our development needs of the host product.
4, the main research contents and objectives
(1) research and development with a hydrostatic transmission axis type axial piston pumps and motors through technology ;
(2) research and development of high-pressure through-shaft axial piston pump with load sensing control technology;
(3) research and development of the overall load sensing with high pressure and chip multi-valve technology ;
(4) research hydrostatic transmission and load-sensing control system parameter matching, dynamic characteristics and testing techniques.
Hydraulic (including hydraulic, the same below), pneumatic seals, is all kinds of modern machinery and equipment, power, transmission and control of critical infrastructure components. They directly determines the performance of the host, the level of quality and reliability. Since the founding of the host compared with all kinds of machinery industry, the industry started late, its development has been severely affected and restricted the host's level of modernization. This aroused national leadership and higher authorities attention in recent years as a key state support of the industry, in the planning, foreign capital, technology and research and development and other aspects of key support. Currently hydraulic, pneumatic and sealing industry is listed as machinery industry revitalization and development of the four priorities.
Goal: strive to "fifteen" at the end, so that research and development of the key components, systems and devices, basically reached the international level the early nineties, tools, equipment must production capacity, to supporting the domestic load sensing hydrostatic transmission and gear adjustment host product commercialization, and lay a solid technical foundation.
(Two) servo proportional technology
servo proportional technology is a kind of tiny electrical signals will be converted to a large proportion of the hydraulic power output of the electro-hydraulic conversion technologies.
Foreign servo technology research began in the 1940s into the 1970s a wide range of industrial applications, has formed a complete product variety, size range, and has a mature product, in order to further expand the application, while maintaining the original basic performance and technical indicators premise toward simplifying the structure, improve reliability and reduce manufacturing costs in the direction of electro-hydraulic proportional servo technology is based on technology for the user to reduce the control characteristics of the hydraulic servo valve can be simplified and developed. Later, proportional solenoid technology development, but also in three categories based on the development of hydraulic valve proportional valve. Dominated by the electro-hydraulic servo proportional component which consists of servo proportional control system, with fast response, power ratio (power to weight ratio) large, high degree of automation and control significant features, so the large inertia, requiring fast response, automatic controlled machine tools, metallurgy, mining, petrochemical, electricity, shipbuilding, military, construction, lifting, transportation and other mainframe products have broad application prospects, are these hosts important a means of control.
Selected on the basis
In industrialized countries, the servo valve, electro-hydraulic proportional valve, and equipped with a dedicated electronic controller and the corresponding hydraulic components, integrated portfolio current proportional servo control system of mutual support development, has been integrated to form hydraulic engineering technology, its application and development is considered to be a measure of a country's industrial level and the development of modern industry established an important symbol of jade, hydraulic engineering industry has a new hot technology and growth. Also a large number of hosts in our product development, require the application of the technology, so as to promote its hydraulic industrial development of key technologies.
Domestic and overseas trends
In recent years, the proportion of servo technology, reflected in a higher concentration of the main basis of their relevant the improvement and development of components, including:
(1) electro-hydraulic servo valve toward simplify the structure and reduce manufacturing costs, improve anti-pollution capability and high reliability direction, research and development High-power magnet linear force motor, forming a new direct drive servo valve product line;
(2) electro-hydraulic proportional valve to the universal, modular, group fully, integrated direction, in order to achieve economies of scale production and lower manufacturing costs;
(3) towards the electronic controller ASIC direction, miniaturization, combination, and to achieve high reliability purposes.
(4) Current servo proportional basis of these major components technologies converge more closely to each other, and the other components increasing the degree of commonality.
Of servo technology began in the 1960s and 1970s with the practical application of products, the current annual production capacity of about 2,000 units; electro-hydraulic proportional technology to the mid-seventies began to develop, the existing dozens of varieties and specifications of products, formed with an annual output capacity of about 5,000. Overall, the proportion of electro-hydraulic servo technology and a larger gap than the international level, the main problems: the lack of leading products, existing product model specifications messy, incomplete varieties and specifications, and the lack of adequate industrial pilot studies, performance levels low quality of instability, poor reliability, and the existence of secondary problems such fittings are hampered further expand the application of this technology, and to improve urgently.
Main research content and objectives
(1) research and development of direct-drive servo valve technology;
(2) Research and development threaded cartridge electro-hydraulic proportional valve technology;
(3) research and development of three types of valve electro-hydraulic proportional valve technology;
(4) the proportion of electro-hydraulic servo technology infrastructure between components parts, components common, combination, integrated, modular technology.
Goal: strive to "fifteen" at the end, research and development of technology, the main basis of electro-hydraulic servo proportional component products, basically complete varieties and specifications for products supporting the host country to meet the rate of 90% products reached the international level of the early nineties, and the formation of production capacity.
(Three) and modular pneumatic intelligent application of technology integration
pneumatic smart , and modular integrated application technology, refers to the province in the development of wiring, low-power miniature solenoid valve series, based on the pneumatic technology and computer technology, information technology, combine to form intelligent pneumatic system, and further integration, modular, can be formed through a combination of space, the provincial wiring, pressure loss, high efficiency, fast response, good reliability, ease of maintenance of gas-electric integration of intelligent health products. Abroad, has been more widely used in industrial automation, automation products to meet each host supporting the development needs, has a broad development prospects.
Selected on the basis
China, with the development of industry, especially machine tools, automobiles, metallurgy, petrochemical and other industrial equipment, greatly improved the level of automation , as well as food, packaging, microelectronics, biotechnology, pharmaceutical, textile and other industries to develop. Required for a variety of efficient, versatile, automated equipment and automated production lines, there is a pressing need to complete such a gas-electric integration products. Therefore, intelligent and integrated modular pneumatic technology development and application, not only is the development of an international pneumatic technology trend, but also China pneumatic industry must accelerate the development of a tracking direction, should focus on the development as the key technology, increasing its research and development efforts.
abroad, pneumatic intelligent and integrated modular technology developed very rapidly, there are a large number of wide range, fairly numerous varieties pneumatic components, to achieve miniaturization, combined, integrated and modular, they have a compact structure (such as miniature solenoid valve minimum width only 10mm), low power (most of the control power 1-2W, the minimum 0.35- 0.5W), fast response (response time of 10-25ms), oil-free, long life (50 million -1 billion times) and other features that can be easily composed valve and computer peripheral equipment and technology used in pneumatic systems, that the formation of intelligent pneumatic systems and products.
Our country on the basis of the introduction of technology, has developed a low-power (control power 1.4-1.8W), does not supply a small electric control valve of new products, and the use of multi- core plug, junction boxes, etc., according to need any installation from 2-10 Union, composed of the valve island, the main performance basically reached the level of similar products in the nineties.
Main research content and objectives
(1) serial-parallel conversion technology research;
(2 ) CPU software development and research;
(3) ¦Õ1 ~ 3 diameter pneumatic components series design and development research;
(4) miniature low-power integrated module design technology;
(5) miniature low power pneumatic solenoid valve manufacturing technology research.
Goal: strive to "fifteen" at the end, be able to grasp pneumatic intelligence and integrated modular technology, the development of a number of micro and small, low-power, combined, integrated gas-electric integration components and systems, so that domestic and imported equipment maintenance for the host gas electrical integration component products, full support to meet the rate of 80%.
(Four) hydraulic system contamination control and sealing technology
pollution control hydraulic system mainly refers to oil purification, to prevent the ingress of contaminants hydraulic systems and manufacturing processes to improve Parts cleanliness of a technology. Sealing technology mainly refers to the hydraulic system to prevent leaks and to prevent the ingress of contamination of a technology.
Hydraulic and pneumatic sealing technology and pollution control systems, direct impact on product quality and reliability, but also affect the performance of products, further supporting host devices are precision, performance, quality and level plays a key role. According to relevant statistics show that 70% of the hydraulic system failure is due to pollution caused by unreliable and seals. Therefore, hydraulic and pneumatic products only to improve the design, improve the precision, it can not fundamentally solve the problem, must be accompanied by strict and effective pollution control and reliable seal can be effective in order to fully reflect the product design and processing brings advanced .
Selected on the basis
hydraulic and pneumatic products pollution control and sealing technology research, on the one hand, hydraulic and pneumatic products solve our country's dirty, drain and action is not reliability issues such as import substitution to improve domestic component matching rate to meet the economic development needs of various industrial sectors of great significance; the other hand, the technological research have great technical difficulty, it relates to the design, manufacture, use , testing, cleaning devices and other aspects, must address all aspects of the different characteristics and adopt scientific methods and effective management purification methods, and have a really good job in order to completely solve the problem. Therefore, the need to address the current technology as the key technology.
Trends at home and abroad in advanced industrial countries
of hydraulic and pneumatic products pollution control and sealing technology are paying special attention, because it directly affects the product performance, quality and level of product whether the market big problem. The basic situation is that the current induction:
(1) implement pollution control products in each product component manufacturing processes, product assembly, product testing and packaging, there are rigorous quantitative indicators table card product cleanliness situation, there is a strict anti-rust and other measures to ensure product storage and transportation of cleanliness;
(2) formulate appropriate standards and norms for the implementation of relevant personnel in accordance with, and discipline;
(3) hydraulic and pneumatic products for users in the use of a clear cleanliness requirements, and related accessories to ensure cleanliness for users to choose;
(4) the product of the pollution control into everyday the scope of work, ready to solve problems;
(5) special attention for the product in seal technology research, in order to ensure a reliable seal products;
(6) In order to meet the host product pressure, high speed, high or low temperatures supporting the development of seals for the needs of the forward foreign portfolio expanded rubber, rubber composite sealing applications; research non-contact controllable diaphragm seal; exploring the application of new flexible graphite sealing materials.
Our country, for hydraulic and pneumatic products, pollution control and sealing technology is also very seriously, but so far the research on the technology, implementation and results achieved, compared with the advanced industrial countries, still There are many gaps, increase research efforts need to continue to point to an area, targeted to make better grades.
4. Research studies content and objectives
(1) research and development of high- Performance parts cleaning equipment technology;
(2) research and development of high precision pollutant carrying capacity of filtration products technology;
(3) research and development of new gas purifying device technology;
(4) of hydraulic and pneumatic components and systems manufacturing process pollution control technology;
(5) of large-scale, high-speed, composition and polymer materials, rubber sealing products, development, testing and evaluation of technical life;
(6) of the mechanical power station sealing structure, special processing, as well as materials and matching technology;
(7) of various parameters, high performance, high reliability, large flexible graphite seal development and testing technology.
Goal: strive to "fifteen" at the end, the manufacturing process for hydraulic and pneumatic products pollution control, pollution control and the application process during the test factory pollution control, cleanliness problem solving products (Governance dirty) so cleanliness is not high because the product caused by the product quality and reliability issues been resolved, the products meet the relevant national standards cleanliness requirements; for hydraulic and pneumatic products and systems, from seals, joints and screw-in cartridge product structure, etc. basically solved leakage problem (governance leakage); pair of seals, and strive to 60% of the products reached the international level of the early nineties.
(3) of hydraulic and pneumatic usual standard library and establish specific parameters of the gallery.
Goal: In China Hydraulics Pneumatics computer application technology on an ongoing basis, will promote China's rapid development of new products of hydraulic and pneumatic adjustment of product structure. Strive to "fifteen" at the end, so that our hydraulic and pneumatic components and products of different specifications, on an ongoing basis to more than double.
Achievements in recent years
hydraulic, pneumatic and sealing industry has formed a relatively complete, a considerable competitive strength, begun production scale industrial system. According to statistics, more than 400 major companies, including 35 key enterprises, the output value and yield more than 65% of the total industry. 1998 National hydraulic industry output value of 2.8 billion yuan (235 million yuan including hydraulic), yield 4.5 million (including hydraulic 62,000 / set); pneumatic industry output value of 600 million yuan, yield more than 300 million pieces. Mechanical system seals 892 million yuan output value. By 1996 the international industry statistics, hydraulic industry output value accounted for sixth in the world. Pneumatic industry output value accounted for tenth in the world.
Since reform and opening, the rapid development of hydraulic and pneumatic sealing industry, has introduced more than 60 foreign advanced technology, in which more than 40 items of hydraulic, pneumatic 5, digestion and absorption and transformation, is have mass production, and become the industry's leading products. In recent years, the industry has increased the intensity of technological transformation, from 1991 to 1998, national, local and corporate self-financing total investment of about 20 billion yuan, of which more than 1.6 billion yuan hydraulic. Through technological innovation and technical research, a number of major companies to further improve the level of technology, process equipment have been greatly improved, in order to form a starting point, specialization, mass production and lay a good foundation. In recent years, a variety of ownership in the country under the principle of common development, the rapid rise of small and medium enterprises of different ownership, showing the vitality. As the country further expand opening up, the rapid development of foreign-funded enterprises, in order to raise the level of industry and plays an important role in expanding exports. At present, China has and the United States, Japan, Germany and other countries of the famous manufacturers to establish a piston pump / motor, planetary gear, steering, hydraulic control valves, hydraulic systems, hydrostatic transmission, hydraulic parts casting, pneumatic control valve, cylinder , air handling components, mechanical seals, rubber seals and other plastic products production joint venture or wholly-owned enterprises, more than 50 foreign investment more than 500 million U.S. dollars. P>