After the founding of New China, especially in the past 30 years, China's mechanical science and technology has developed rapidly. To the trend of large-scale, precision, automation and complete sets of mechanical products. In some respects, it has reached or surpassed the advanced level in the world. Generally speaking, at present, China's mechanical science and technology has made great achievements, and its development speed and level are unprecedented. This period is not over yet, and China's mechanical technology will develop to a higher level. As long as we can adopt correct principles and policies, make good use of the law of scientific and technological development, and be brave in innovation, China's machinery industry and machinery technology can regain their vitality and lead the development trend of the world machinery industry.
As far as small tamping machines are concerned:
Before the 1960s, there was a lack of small tamping machines in China, and the tamping of many small sites was basically done manually.
In the early 1960s, Changsha Institute of Construction Machinery cooperated with Beijing Institute of Civil Engineering and Architecture, and invented a frog rammer with China characteristics on the basis of a large number of technological innovations, and won the 1962 National Science and Technology Invention Award. Frog rammer has simple structure and convenient maintenance and use, and soon became the leading product of tamping machinery in China in the 1960 s. According to incomplete statistics, the cumulative output of frog rammers has reached more than 50,000 sets, which has played an important role in China's economic construction. After 1970s, frog rammer was gradually replaced by more advanced vibration impact rammer and vibrating plate rammer. At present, frog rammers are rare and basically eliminated.
1964, Changsha construction machinery research institute developed HB 120 internal combustion compactor, which was first produced by Shanghai construction machinery factory and later mainly produced by Tianjin Dongting construction machinery factory, with an annual output of about 200 sets. In 1980s, the quality of internal combustion compactors was greatly improved and exported to Southeast Asia and Africa. After the 1990s, the production and sales of internal combustion engines declined gradually. At present, only a few small private enterprises produce them.
1977, Changsha Construction Machinery Research Institute and Liuzhou Construction Machinery Factory developed the first domestic vibration plate rammer of HZR250 and HZR70. These two products passed the appraisal organized by the Ministry of Construction in 1979 and 1982 respectively. Subsequently, Yiwu construction machinery factory, Siping construction machinery factory, Anyang vibrator factory, Tianjin Dongting construction machinery factory and many other enterprises began to produce vibrating plate rammers. 1986, Changsha Institute of Construction Machinery developed a larger HZR450 vibrating plate rammer. Since 1990s, vibratory plate compactors have developed rapidly in China, with more and more varieties, specifications and manufacturers, and foreign vibratory plate compactors have also entered the China market.
1983, Changsha construction machinery research institute and Hubei vibrator factory jointly developed the first domestic HZR70 vibration impact rammer, which passed the appraisal organized by the Ministry of Construction in 1984 and won the third prize of scientific and technological progress in 1985. Because of its outstanding features, such as good compaction effect, high productivity, small volume and weight, portability and flexibility, the vibratory impact rammer is deeply welcomed by users and quickly popularized and used, and soon developed into dozens of enterprises such as Zijiang Machine Tool Plant, Xinxiang No.3 Machine Tool Plant and Tianjin Dongting Construction Machinery Plant. Although the development of vibratory impact rammer is later than that of vibratory plate rammer, its development speed, production and sales volume and wide application are far greater than that of vibratory plate rammer, and it has become the leading product with the largest production and sales volume among rammers in China. After 1990s, foreign vibrating plate rammers entered the China market one after another.
The successful development of vibratory impact rammer and vibratory plate rammer in China has not only provided advanced tamping machinery for the construction department in China, but also achieved good economic and social benefits, which has made the tamping machinery technology in China take a big step forward, shortened the gap with the advanced level in the world and promoted the development of tamping machinery in China.
As far as processing is concerned:
According to archaeological findings, bronze ritual vessels from the 6th century BC/KLOC-0 (Shang Dynasty) were unearthed in Pinggu, Changping and Fangshan in Beijing. During the Yongle period of the Ming Dynasty (1403 ~ 1424), Beijing manufactured the world-famous Ming Yongle bronze bell (46.5 tons), bell tower bronze bell (63 tons) and iron bell (25 tons), which were cast by furnace melting, pit molding and Fan Tao method. Before 1950s, Beijing used clay sand for manual modeling in casting. 1955, Beijing No.1 Machine Tool Plant began to adopt leaky mold modeling, double-sided model board, iron plate and standard sand box modeling. 1965, made of plastic. 1980, Beijing Institute of Mechanical and Electrical Technology and Beijing Masteel General Factory successfully developed a power frequency coreless plug-rod bottom-pouring thermal insulation pouring electric furnace. 1982, the institute and Beijing Machine Tool Foundry No.2 Factory successfully studied the tuyere oxygen blowing technology of cupola. From 1985 to 1988, the pressure casting process of floating end face sealing ring was successfully tested in Beijing Machine Tool Research Institute.
Forging 1959, Beijing Second General Machinery Factory (later renamed Beijing Heavy Machinery Factory) built a 2500-ton hydraulic press. 197 1 year, the factory produced 6000 tons of hydraulic press, which was the largest forging equipment in Beijing at that time. From 1968 to 1979, Beijing Crane Machinery Factory used 300-ton hydraulic press and 2000-ton hydraulic press to manufacture crane boom and large-scale covering parts. In 1980s, Beijing Electromechanical Research Institute and Beijing Mould Center developed a series of high-precision multi-position blanking dies, which were close to or reached the level of imported dies, and changed the situation that Beijing precision blanking dies depended on imports.
Before heat treatment 1949, Beijing has used electric furnace, molten salt furnace, thermocouple and other means to anneal, temper, quench, normalize, temper and carburize the parts. From 65438 to 0956, Beijing No.1 Machine Tool Plant began to adopt high-frequency induction quenching. 196 1 year, Beijing second machine tool plant began to adopt gas nitriding quenching. 1969, Beijing measuring tool factory began to adopt bright quenching. 1978, Beijing machine tool research institute has completed the research on the surface contact quenching technology and equipment of machine tool guide rail and the technical conditions for quenching quality inspection. During the period of 1979, the Research Institute of Railway Science cooperated with the Institute of Mechanics of Chinese Academy of Sciences to complete the research on the surface laser modification of cylinder liner of high-power diesel engine. From 65438 to 0979, Beijing Institute of Mechanical and Electrical Engineering successfully developed a kilowatt-class carbon dioxide laser, which was applied to the laser heat treatment of cylinder liners and stamp printing equipment in the early 1980s. Among them, Tsinghua University, Beijing Electromechanical Research Institute and Beijing Stamp Factory * * completed the laser strengthening research on the surface of the punch of the seven-color machine in the stamp factory. From 1984 to 1990, Beijing Heat Treatment Research Institute has successfully studied and applied new heat treatment technologies, such as vacuum heat treatment, microcomputer control technology of gas carburizing (in cooperation with Beihang University), soft nitriding of rare earth, surface strengthening of powder metallurgy products, computer-controlled carburizing with kerosene and methanol, solid boronizing, computer-aided process design and tracking control system of carburizing process. Welding and cutting were carried out in 1949, and manual operations such as gas welding, arc welding and oxyacetylene flame cutting were all carried out in Beijing. 1963, TIG welding was developed by Beijing Metal Structure Factory in cooperation with the Institute of Mechanical Science of the First Ministry of Machinery, and nitrogen plasma cutting of stainless steel was realized. 1964 the welding of pure nickel in inclined electrolyzer for nuclear industry is solved by DC tungsten argon arc welding and welding wire alloying technology. 1966, Beijing metal structure factory developed submerged arc welding to make the welding ball rotate. 1968, the factory began to use liquefied petroleum gas instead of acetylene cutting. In the early 1980s, Tsinghua University invented a new arc control method for MIG welding, and made a breakthrough in arc control technology. In the early 1980s, Beijing Urban Construction Design Institute and others completed the research and application of mobile pneumatic rail welding technology for liquefied petroleum gas. From 65438 to 0990, Beijing Metal Structure Factory began to adopt photoelectric tracking, CNC precision cutting and high-power plasma cutting technology with automatic programming of CNC tracing readings.
It can be seen that machinery in China has developed rapidly since modern times.
China is the first country in the world to develop machinery. China's mechanical engineering technology not only has a long history and brilliant achievements, China not only plays an important role in the world's material culture and social and economic development, but also makes great contributions to promoting the progress of civilization and China's traditional mechanical technology. For a long time to come. In modern times, especially from the beginning of18th century, due to the economic and social reasons in the 1940s, China's machinery industry stagnated. In 10, it was the western bourgeois political revolution and industrial revolution, and the mechanical science and technology developed rapidly, far exceeding the level of China. As a result, the gap between China's mechanical development level and that of the West has widened sharply, and by the middle of the 9th century, it was one hundred years behind the West.
After the founding of New China, especially in the past 30 years, the development of mechanical science and technology in China has accelerated. The development trend of large-scale, precision and automation of mechanical products is discussed. In some respects, it has reached or surpassed the world advanced level. Generally speaking, at present, China has made great achievements in mechanical science and technology, and its development speed and level are unprecedented. During this period, China's mechanical science and technology will develop to a higher level. As long as we can adopt correct policies and rely on good technical development and innovation, our machinery industry and machinery technology can be revitalized, thus leading the development trend of machinery industry.
Just a small stamping machine:
In the1960s, there was a shortage of small rammers with few machines in China, and the rammers in many small sites basically used manual rammers.
Early 1960s, Changsha Institute of Building Machinery, Beijing Institute of Civil Engineering and Architecture, etc. On the basis of summarizing the technological innovation achievements with China characteristics, the frog rammer was invented, and 1962 surpassed the national science and technology. Frog rammer is simple in structure and convenient to use and maintain. In 1960s, it quickly becomes the leading product of tamping machinery. According to incomplete statistics, the cumulative output of frog rammer has reached more than 50,000 sets, which has played an important role in China's economic development. Since 1970' s, frog rammer has been gradually replaced by vibration impact rammer and vibration plate rammer with more advanced performance. Now frog rammer is rarely used and basically eliminated.
1964, Changsha construction machinery research institute developed HB 120 movable-type and Shanghai movable-type track-laying machines. Later, construction machinery was mainly produced by Tianjin municipal government, and about 200 Dongting construction machinery were produced every year. In the1980s, the quality of movable-type rammers was greatly improved and exported to Southeast Asia and Africa. Since 1990s, the production and sales of internal-combustion tamping machines have gradually decreased, and they are only produced in a few small private enterprises.
1977, Changsha Construction Machinery Factory developed HZR250 and HZR70 vibrating plate compactors in Liuzhou, and these two products passed the acceptance organized by the Ministry of Construction in 1979 and 1982. Subsequently, Yiwu Construction Machinery Factory, Siping Anyang Vibrating Rod Factory, Tianjin Municipal Engineering Machinery Dongting and other enterprises began to produce vibrating plate rammers. In 1986, Changsha construction machinery has developed a larger type of HZR450 vibrating plate rammer. Since 1990s, vibratory plate compactors have developed rapidly in China, with more varieties, specifications and manufacturers, and foreign vibratory plate compactors have gradually entered the China market.
In 1983, 1984, the first HZR70 vibration impact rammer jointly developed by Changsha Construction Machinery Research Institute and Hubei Vibration, passed the construction technology progress award organized by the Ministry of Construction and won the grand prize in 1985. Because of its outstanding characteristics such as good compaction, high productivity, small volume, light weight, portability and flexibility, the vibration impact compaction effect has been favored by users and quickly popularized, and has quickly developed to dozens of factories such as Zijiang Production Plant, Xinxiang Municipal Engineering Machine Tool Plant and Tianjin Dongting Production Plant. Although the vibratory impact rammer is not as good as the vibratory plate rammer, its later development speed, production and use are more extensive than the vibratory plate rammer, and it has become the largest tamping mechanical product in China. Since 1990s, foreign vibratory plate compactors have gradually entered the China market.
The successful development of vibro-impact rammer and vibro-flat rammer in China not only provided advanced machinery for the construction sector in China and achieved good economic and social benefits, but also made China's tamping machinery technology take a big step forward, shortened the gap with the world's advanced level and promoted the development of compaction machinery.
Machining:
According to archaeological findings, the hot-working casting in Pinggu and Changping in Beijing has proved the bronze wares of Shang Dynasty in BC16th century. During the Yongle reign of the Ming Dynasty (1403- 1424), the world-famous Ming Yongle Big Three Bell (weighing 46.5 tons) and Tower Big Three Bell (weighing 63 tons) were produced in Beijing by melting iron clocks and furnaces, and the pits were made of Fan Tao model and casting method. /kloc-in the 1950s, clay sand was mainly cast by hand in Beijing. 1955, Beijing No.1 Machine Tool Plant began to adopt leaky mold molding, double-sided molding, iron plate molding and standard sand box molding. In 1965, plastic models were used. In 1980, the institute and Beijing Electric Appliance Factory successfully developed the power frequency coreless bathroom plug pole bottom injection electrical insulation casting. 1982, Beijing Foundry Institute studied the oxygen blowing technology at the tuyere of cupola. 1985- 1988, the floating end face sealing ring of Beijing Institute of Machinery passed the die pressure test casting process successfully.
1959, Beijing No.2 Forging Machinery General Factory was restructured into a 2500-ton heavy-duty hydraulic press in Beijing. 197 1 year, the factory produced 6000 tons, which was the largest forging equipment in Beijing Heidsite at that time. 1968- 1979, Beijing lifting machinery factory has 300 tons, uses 2000 tons of hydraulic press and manufactures cranes and large panels. In the1980s, Beijing Electric Appliance Research Institute developed a series of high-precision blanking dies in Beijing Die Center, which approached or reached the level of imported dies in many stages, changing the dependence of Beijing precision blanking dies on imports.
Before 1949, there was a heat treatment furnace in Beijing, which used thermocouple to carry out salt melting furnace, quenching and tempering, annealing of parts, normalizing, quenching and tempering, carburizing and so on. 1956, Beijing No.1 Machine Tool Plant began to use high-frequency quenching. 196 1 year, Beijing second machine tool plant began to use gas nitriding quenching. 1969, enterprises below Beijing Gauge began light quenching. 1978, Beijing machine tool research institute completed the contact quenching process and equipment of guide rail surface and the inspection conditions of quenching quality. 1979, china academy of railway sciences and Institute of Machinery cooperated in laser surface modification of cylinder liner of high-power diesel engine. In 1979, Beijing electric research institute developed a carbon dioxide laser, which was applied to laser processing roller and stamp printing equipment respectively in the early 1980s. Among them, Tsinghua University, Beijing Youpiao Factory and Beijing Electric Research Institute have jointly completed the research on laser surface strengthening of the seven-color machine and large empty machine in Youpiao Factory. 65 438+0984 to 1990, Beijing Institute of Vacuum Heat Treatment, Microcomputer Control Technology of Gas Carburizing (Beihang University; Aerospace and cooperation), rare earth soft nitriding, surface strengthening of powder metallurgy products, micro-computer controlled carburizing method of kerosene and methanol, computer-aided process planning and tracking control system of solid boronizing and carburizing process, and the application heat of new technologies in production. Welding and cutting in 1949, Beijing has manual operation of oxyacetylene flame such as geological drilling, electric welding and cutting. 1963, Beijing Metal Structure and the Institute of Mechanical Science of the First Ministry of Machinery jointly developed TIG welding, and realized nitrogen plasma cutting of stainless steel. In 1964, DC argon arc welding and tungsten wire alloying technology were used to solve the problem of pure nickel welding deteriorated by inclined electrolysis industry. 1966, Beijing metal structure factory developed submerged arc welding with rotating sphere. 1968, the factory began to use liquefied petroleum gas instead of acetylene cutting. 1In the early 1980s, Tsinghua University invented a new MIG welding arc control technology and made a breakthrough in arc control. As early as 1980' s, the research and application of liquefied petroleum gas mobile pneumatic rail welding technology was completed in Beijing urban construction design. 1990, Beijing metal structure factory adopts CNC precision cutting and plasma cutting with photoelectric tracking and CNC pursuit of high-input automatic programming technology.
Visible, China machinery development in modern times its rapid development.