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The development of piston ring technology comes from two aspects: First, the development of the whole machine promotes the progress of piston ring technology. The level of independent research and development of the whole machine will be improved, and the piston ring technology will also be improved. Second, the piston ring enterprises take the route of high-end technology and actively promote the application of new technologies on the whole machine. Domestic piston ring enterprises basically rely on the introduction of foreign technology to improve their technical level. The technical development trend of the piston ring industry in recent years is the material steel, the thinning of the piston ring and the high-end surface treatment. Since the piston ring is both a key component of the engine and one of the most demanding friction parts in the engine, the piston ring is required to have high resistance to fusion wear. Finding new materials and new surface treatments has become the main technical focus for the piston ring industry to meet future market demands. Steel materialization and thin piston ring are the development trend of piston ring technology The piston rings of conventional automotive diesel engines generally use ductile iron and alloy cast iron, and the piston rings of gasoline engines are generally made of steel. As the vehicle engine develops toward high reinforcement, high output power, and light weight, the piston ring becomes thinner and the weight becomes lighter, which requires the piston ring to have high strength (thermal fatigue strength), and the material for the piston ring of the vehicle engine. There has been great development: ordinary gray cast iron - high alloy cast iron - ductile iron - steel. In recent years, steel piston rings, which used to be used in gasoline engines, have been gradually introduced into the diesel engine field, and some diesel engines have begun to adopt steel oil rings. Compared with the cast iron ring, the steel piston ring does not require a casting process, is light in weight, and has a simple processing method. Domestic mainstream manufacturers have invested in the research and development and production of new steel rings. The proportion of steel rings used in the automotive diesel industry is also high. Another trend in the development of piston ring technology is that the height of the piston ring becomes smaller, that is, it is thinner. When the height of the piston ring becomes smaller, the tightness between the piston ring and the cylinder liner is enhanced, and the probability of oil entering the combustion chamber is reduced, so that the pollution pollution can be reduced. At present, it is gradually promoted and applied in the field of vehicle diesel engines and gasoline engines. High-end surface treatment technology is another trend in the development of piston ring technology Vehicle engines (especially diesel engines) are developing towards high mechanical loads and high heat loads, and the durability requirements of high-output engines are also greatly improved. At the same time, regulations such as low fuel consumption and low exhaust emissions required for environmental protection are coming. The more strict. In view of these circumstances, the wear resistance of the piston ring, the performance of the pull-resistant cylinder, and the sliding characteristics that do not cause too much wear on the cylinder liner are required. The working conditions of the piston ring are high temperature and high pressure, which are extremely demanding. At the moment of explosion of the engine combustion chamber, the gas temperature can reach 2000 °C ~ 2500 °C, and the reciprocating piston speed and load are very large, which poses a great challenge to the surface treatment process of the piston ring. In general, the surface treatment processes for ductile iron and alloy cast iron piston ring piston rings include phosphating, oxidation, and chrome plating. Among them, chrome plating is the process adopted by most domestic manufacturers. However, the chrome plating process has serious environmental pollution, low production efficiency, high scrap rate and production cost of the piston ring, especially the heavy treatment of heavy metals in the waste liquid is difficult. The chrome plating process is gradually reduced abroad, and a large number of new processes of spraying molybdenum, nitriding and spraying ceramics are adopted to reduce environmental pollution, improve production efficiency and use of high-grade piston rings. The steel ring is mostly made of nitriding, molybdenum spraying and PVD. It is more advanced and widely used in the piston ring industry in developed countries, especially in Japan. With the advancement of the domestic engine industry, China's piston ring industry surface treatment process has also been greatly developed, nitriding, molybdenum spray, end flash plating (new technology for piston ring side reinforcement), composite plating (chromium ceramic, CCC), physics Advanced processes such as vapor deposition (PVD), ultra-high speed oxygen flame spraying (HVOF), and chromium diamond composite plating (GDC) are beginning to be applied. Since each process requires a new production line, it has high requirements for technology, production and capital strength. At present, only the two-ring piston ring and Anqing Dibergs have the above-mentioned advanced technology production lines. Piston ring technology needs further development Domestic piston ring enterprises still have a certain gap with foreign countries in technology research and development, which is manifested in four aspects: First, in terms of materials and surface treatment, domestic enterprises are in the initial stage of innovation or basically have no ability to innovate. Yizheng Shuanghuan has passed many years. The research and development of the composite electroplating technology (CCC) with independent intellectual property rights, obtained the national invention patent, and formed the industrial production, the pace of innovation in the industry is at the forefront; the second is in the product bench verification, like the Yizheng double ring even With the gantry laboratory, but it has just started very soon; the third is the lack of product design experience of domestic enterprises, and has only begun to accumulate various data in recent years; the fourth is that the domestic process level is greatly affected by equipment, and it is difficult to ensure the production capacity of complex products. . Fourth, the main competitive landscape of the piston ring industry Host market - double heroes 1, the car diesel engine market - double male hegemony Yizheng Shuanghuan Piston Ring Co., Ltd., Anqing Dibergs Piston Ring Co., Ltd.; Standby to enter the diesel engine host market: Changsha Zhengyuan Piston Ring Co., Ltd., Fujian Huaying Auto Parts Group, Nanjing Feiyan Piston Ring Co., Ltd.; 2, the car gasoline engine market - private enterprises dominate Fujian East Asia Piston Ring Co., Ltd., Anqing Dibergs Piston Ring Co., Ltd., Yizheng Shuanghuan Piston Ring Co., Ltd., Fujian Autopath Piston Ring Co., Ltd.; Maintenance market - the competition 1. Vehicle diesel engine: Yizheng Shuanghuan Piston Ring Co., Ltd., Anqing Dibergs Piston Ring Co., Ltd., Changsha Zhengyuan Piston Ring Co., Ltd., Fujian Huaying Auto Parts Group, Nanjing Feiyan Piston Ring Co., Ltd., Shijiazhuang Jingang [Review Picture Forum] internal combustion engine accessories; 2. Gasoline engine for vehicles: Fujian East Asia Piston Ring Co., Ltd., Anqing Dibergs Piston Ring Co., Ltd., Yizheng Shuanghuan Piston Ring Co., Ltd., Fujian Autopath Piston Ring Co., Ltd., Xiamen Riken Piston Ring Co., Ltd.; 5. Why do many piston ring small factories have room for survival? The piston ring industry has been scattered for a long time and its technical level is low. Recently, many people in the industry have called for the piston ring industry to be integrated only to survive. It is believed that piston ring manufacturers will be less and less like foreign countries. But that is not the case. According to industry experts, the number of piston ring enterprises has not increased as the number of foreign countries has decreased year by year. The market development has not been standardized, but has become more disorderly. China's parts and components industry is becoming more and more complicated. The main reason is that the diversification of products determines that the number of Chinese component companies will not decrease for a considerable period of time. According to some statistics, there are more than 50 piston ring related enterprises in the surrounding areas of Yizheng Shuanghuan. The facts show that many well-known parts and components companies have survived for a long time. According to statistics, China produces more than 40 million engines every year, including the supply of nearly 10 million cars, commercial vehicles, and more than 30 million motorcycles, agricultural vehicles, construction machinery, marine engines and so on. If the piston ring manufacturers are unable to supply cars and commercial vehicles, they can supply other 30 million locomotives, or they can supply a large number of repair markets. With the continuous development of China's national economy and the rapid growth of the automobile industry, the demand for the piston ring market will continue to expand. This also determines that the number of piston ring manufacturers will not decrease but will increase. As the vehicle market expands, the piston ring market capacity will continue to expand, and the variety and quantity of products will increase. It is understood that the protection of local protectionism, the state-owned enterprise system and the huge zero-relationship system in order to maintain the growth of local fiscal revenues have led to insufficient competition, which makes products with low technical level and poor competitiveness exist for a certain period of time, thus low. Enterprises such as inferior and inferior products can survive. However, with the passage of time, China's piston ring manufacturers will follow the international development law, showing a decreasing trend.

PR Newswire, the US Federal-Mogul Group announced on March 1 that it will invest in a joint venture in Changsha to produce a large-bore piston ring. Federal-Mogul Zhengsheng (Changsha) Piston Ring Co., Ltd. for commercial shipping, railways, energy and Off-highway industrial engines provide high-tech piston rings. The new project will become the second large bore piston ring production plant to be invested in China, further perfecting the two-cycle and four-stroke piston ring product portfolio, thereby consolidating its leading position in the industrial piston ring business in China and Asia. The completion of the transaction depends on the usual conditions, including the legal approval of the joint venture. [We expect that with the increase in the industrial engine upgrade in China, the market prospects of high-tech and world-class high-piston piston rings will further increase." Weng Weibo, vice president of Federal-Mogul (China) Co., Ltd., stated that [this investment is a Federal-Mogul company. Another important step in improving the local operations of its globally renowned brand Goetze and DAROS piston bore rings." The new joint venture factory is located in the Changsha Economic and Technological Development Zone and occupies an area of 25,000 square meters. The new production plant will soon be put into operation. The joint venture is controlled by Federal-Mogul, while the Chinese partner invests in shares with its Changsha Zhengsheng Piston Ring Co., Ltd. and will continue to support customer maintenance and customer development. After joint venture with Changsha Zhengsheng Piston Ring Co., Ltd., Federal-Mogul plans to further upgrade and renovate the existing production lines and technology. At the same time, it will introduce a four-stroke production line including ceramic chrome-plated surface treatment to produce low-emission, high-life, high-quality industrial piston ring products. The piston ring is a critical component of large-diameter industrial engines and is a guarantee for smooth and efficient operation under severe operating conditions. The Federal-Mogul Group has world-leading technology for the development and production of large bore piston rings, providing products and services to industrial engine customers worldwide, including Germany's MAN and MTU Group, Finland's Wartsila, Korea's Doosan, Japan's Mitsubishi, and US Caterpillar. And other famous industrial engine manufacturers. [Following the completion of this joint venture, Federal-Mogul will continue to expand the business of the middle and high-end customers in Asia on the basis of continuing to serve the original customers of Changsha Zhengsheng Piston Ring Co., Ltd.," Mr. Weng added. [The joint venture helps us enter the emerging markets. At the same time, it also provides regional customers with better products and services."

The piston ring is one of the most important parts in the internal combustion engine. It plays the role of support, sealing, guiding and heat transfer in the internal combustion engine. Its free-form profile and its machining accuracy directly affect the engine's power, fuel consumption, noise and Service life. For decades, high-efficiency, high-precision piston ring processing equipment has been the goal of people's pursuit, and introduced a variety of machine tools and equipment with different structures and characteristics. This paper will analyze the requirements of the piston ring inner and outer circular cutting machining equipment from the piston ring free state contour line. According to the characteristics and existing deficiencies of the existing piston ring processing equipment, a piston ring numerical control lathe is being developed by the author. Structural plan. 1 Piston ring free profile processing characteristics Analysis of the piston ring free state profile curve determines its performance after loading into the engine cylinder, affecting the circumferential radial pressure distribution, sealing and service life. The free-state profile of the piston ring is closely related to its radial pressure distribution. The design of the piston ring is firstly selected according to its working conditions: the appropriate radial pressure distribution formula, and then the corresponding free state is calculated by mathematical and mechanical methods. The profile line, and then use a variety of special equipment to machine the required inner and outer contour lines. At present, there are ten formulas for the radial pressure distribution of piston rings commonly used in China: there are many kinds, such as the Genzbull format w, Arnold, long-gang, x-type, constant-pressure and so on. The same type of piston ring is calculated by different pressure distribution formulas, and free-form lines of different shapes can be obtained. Although the difference is not very large, only in the range of lmm, the piston ring free-form line is extremely sensitive to its working pressure distribution. Therefore, in order to obtain the ideal piston ring pressure distribution, it is necessary to machine a precise contour curve of the free state of the piston ring. Regardless of the pressure distribution formula used, the resulting piston ring is free: division. Research direction: Numerical control technology, mechatronics technology, won the third prize of the provincial scientific and technological progress 2, the city's second prize for scientific and technological progress. E-mai: cimsyzu.edu.cn: The shapes are similar. It is a typical piston ring medium-diameter free-form curve, which is symmetrically distributed with respect to the opening, and its maximum median diameter is generally at 11 120°, and the opening width is generally performed on the piston ring at a uniform rotational speed n (r/min). For cutting, the radial cutting speed and acceleration of the piston ring can be calculated as follows: the free-form line of a typical piston ring of the double-ring piston ring company and its analyzed velocity curve and acceleration curve. As can be seen from the figure, when the workpiece rotation speed is n=180r/rain, the maximum acceleration can be calculated from equation (2) to be 14.66m/s2. This requires the piston ring processing equipment to have high feed acceleration and fast system. The frequency response function, which is difficult to satisfy for the usual CNC systems and servo motors. 2 Piston ring inner and outer circular cutting processing equipment At present, the domestic piston ring inner and outer circular free line processing is dominant in the mainstream is the pl which is realized by the mold, which uses the master control tool to make the radial displacement to process the required piston. Ring shape inside and outside the circle, this equipment structure Xiao line motor L! ! J1 spindle system? Jf servo motor-*1z axis high efficiency high precision piston ring CNC machining machine structure scheme The encoder is simple, the price is moderate, the work is reliable However, the mold manufacturing cycle li, j processing precision is low. Can not be timely and flexible according to piston ring model and parameter requirements! It is difficult to meet changing market demands by changing the model. In the Song Dynasty in the 1990s, the National University of Defense Technology developed a numerically controlled profiled piston ring lathe 1MI using a stepper motor and a sinusoidal feed mechanism. It can process various piston ring pressure distribution curves and improve the piston ring: processing efficiency. The production cycle of the live cold ring is greatly shortened. The machine and milling compound vertical full CNC piston ring machine of a Japanese machine tool has also been applied in a few piston ring production enterprises: but the cutting process of the equipment is still based on imitation. The working principle of the shape requires a sinusoidal cam machine to drive the cutting tool to complete the feed motion, so there is still a problem of wear and replacement of the cam. The stepping motor has a low response frequency and cannot meet the requirements of high-speed machining. In Japan, a machine tool company introduced a vertical and full CNC piston ring machine in the 1990s. The right half is the turning part. The left part is the milling part, the turning part and the milling part each have 4R servo feed motor, and one R automatic detection motor, which consists of 9 servo motors. The whole machine has a complicated structure and is expensive, up to more than 600,000 US dollars. For most of the piston ring manufacturers, its expensive price is unbearable. 3 High-efficiency and high-precision piston ring internal and external machining strategy From the current analysis of the existing equipment in the piston ring internal and external circular machining, the trend of piston ring cutting is CNC machining, relying on the model to obtain the free-curve shape of the piston ring is difficult to adapt to today's ever-changing market requirements. The biggest problem facing the piston ring CNC machining comes from two aspects: ~ is the CNC system that needs high-speed processing function Second, there must be a tool feed drive mechanism that meets the requirements of acceleration characteristics. With the development of microelectronics cooking, in recent years, the numerical control system The calculation speed: the degree is greatly improved. The high-speed CNC system of 32-bit or even 64-bit chips has been widely used in industrial applications. The motion controller based on digital signal processor (DSP) has also gradually matured, thus meeting the requirements of piston ring processing. The high-speed CNC system has a large selection space: for the drive, if it is still through the combination of the traditional i servo motor and a ball screw, it is difficult to meet the high acceleration requirement 'soft master' working principle, the ball screw The acceleration is usually only 0.50.6g, even if the large lead ball screw can only reach about lg. In recent years, linear motors have developed rapidly and are gradually applied in various industrial fields. Linear servo motors can directly provide linear motion without Any mechanical connection, no backlash, fast moving speed (up to 58m/s), high acceleration (510f and fast response capability), ideal for piston ring machining feed drive system: Yangzhou University Electromechanical Research Institute and Yizheng Shuanghuan Piston Ring Co., Ltd. is cooperating to develop a new type of high-efficiency and high-precision piston ring CNC machining machine for this machine The structural scheme adopts an ordinary AC servo motor and a linear servo motor to control the axial feed and the radial feed motion of the piston ring machining, the angle information collected by the spindle rotary encoder and the diameter of the linear motor Coordinating the displacement to the displacement, constructing a "soft master" through the high-performance CNC system, which replaces the normal hard master to complete the machining of the piston ring free profile: for the working principle of this "soft master": The piston ring machining machine solution constructed by linear servo motor and high-performance numerical control can solve the high-speed response and high acceleration characteristics required for free-form line processing of piston rings, and has the characteristics of high response frequency and fast product modification. Is a development direction of today's piston ring machine tools.

Due to the development of high-intensity, high-output, and light-weight automotive engines, piston rings have become thinner and lighter in weight, requiring piston rings with high strength (thermal fatigue strength). In recent years, steel piston rings used in gasoline engines in the past have been gradually introduced into the diesel engine field. Some diesel engines have begun to use steel oil rings. As the height of the piston ring becomes smaller (thinner), the tightness between the piston ring and the cylinder liner is enhanced, which reduces the chance of the oil entering the combustion chamber and further reduces the emission pollution. At present, thin piston rings have been gradually applied in the fields of vehicle diesel engines and gasoline engines. Vehicle engines (especially diesel engines) are evolving toward high mechanical loads, high heat loads, low fuel consumption, and low exhaust emissions. They place higher demands on the piston rings: wear resistance, pull cylinder performance, and cylinder resistance. The sleeve will not cause too much abrasive sliding properties, which in turn will promote the popularization of advanced surface treatment technology in the field of piston rings. For example, in the developed countries, especially the piston ring industry in Japan, the steel ring of the developed countries has now adopted a large number of advanced nitriding, molybdenum spray, and PVD processes.

Recently, Yizheng Shuanghuan Co., Ltd. cooperated with a domestic university to develop a piston pressure distribution characteristic curve tester. Recently, the first instrument was put into use at the company. The instrument adopts a unique pressure detection system. The pressure is installed during the measurement. The measured piston ring pressure distribution data is exactly the same as when the piston ring is installed. The instrument operates at a constant temperature and the measurement process is fully automated. The control completely eliminates the influence of environmental factors and human factors on the measurement results; the instrument also has extremely high repetition measurement accuracy. At present, the company is the only piston ring manufacturer in China that has piston ring pressure distribution characteristic detection technology.