Eight technological advances of the hottest modern

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From the 1980s to the beginning of this century, the technology of domestic and foreign construction machinery products has moved from a mature period to a modern period. With a new technological revolution, the comprehensive technical level of construction machinery products has jumped to a new level. Electronic technology, microcomputer, sensor container bottom plate testing machine is mainly used for static bending strength, elastic modulus, bonding strength, mechanical property tester of impregnation and stripping performance of plywood and bamboo bottom plates used for container support goods. The integration of electrohydraulic servo and control system has transformed the traditional construction machinery products, and computer-aided design, auxiliary manufacturing and auxiliary management have equipped the construction machinery manufacturing industry, It network technology is also equipped with the sales and information transmission system of construction machinery, so that people can see a new construction machinery industry. New construction machinery products are unparalleled in many aspects such as work efficiency, operation quality, environmental protection, operation performance and automation, and are moving towards further intellectualization and roboticization

1. Innovation of operation principle: new method of earth breaking and high-frequency vibration

with the continuous development of scientific and technological research level, the operation theory of construction machinery is also constantly innovated. The operation principle of construction machinery includes cutting, crushing and backfilling of earthwork, screening, mixing and heating of geotechnical materials, paving, leveling and compaction of mixtures, etc. These operating principles were originally based on bionics and Newtonian mechanics, and the development of modern science has laid the foundation for the innovation of operating principles of construction machinery. For example, the application of mechanical vibration, pulse, jet, photoelectric effect and thermophysics has created conditions for engineering machinery to save resources, improve construction quality, improve production efficiency, work reliability, driving comfort and automation

excavators, bulldozers, loaders and other earthwork machinery cut and break the soil. Now there are bucket free milling method, high-frequency vibration method, liquid air jet method and microporous soil breaking method. The bucket and scarifier modified with the new earth breaking operation principle can excavate high-strength rock and soil, which can generally reduce the unit earthwork cost and improve the production efficiency, and can replace the drilling blasting method when excavating near the building

vibratory roller is the most powerful explanation for using mechanical vibration to achieve the operation effect of "vibrating the ground but not people". The application of high-frequency vibration compaction technology is an important scientific research achievement of modern dynamics in construction machinery. The theory of vibration and vibration isolation are applied to the vibratory roller at the same time. Since the 1990s, there have been directional vibration compaction methods of horizontal vibration (oscillation) and vertical vibration, as well as vibration compaction principles such as stepless amplitude modulation vibration and chaotic vibration different from simple harmonic vibration, and a corresponding series of vibratory rollers have been formed. The impact roller breaks the original traditional cylindrical roller structure, and uses a polygonal roller with edges to impact the ground in order of times per second. This kind of violent impact has the propagation characteristics of seismic waves, and its compaction depth increases with the number of rolling passes, and the compaction degree at 5m depth can reach 90% - 92%. The impact roller has the comprehensive effects of static pressure impact, vibration compaction and kneading, and is suitable for the compaction of large-scale filling, collapsed soil and dry sand filling projects

the leveling working device of asphalt concrete paver is a typical example of the innovation of the working principle of construction machinery. The comfort plate uses diesel, liquefied gas or electric heating and 72HZ frequency modulation vibration, and uses infrared, laser or ultrasonic leveling, which is the application of multidisciplinary high-tech. The leveling technology can also be applied to the grader as the fine leveling of the ground or slope

frequency modulated mechanical vibration is also commonly used in rock drilling, stone crushing and screening, pile sinking and pulling and other engineering construction. The burners of diesel, heavy oil and pulverized coal can be used for the drying of stones. The principles of thermophysics are fully used in the process of asphalt barrel removal, heating and asphalt mixture mixing and insulation. The emulsification and modification of asphalt are the specific applications of some chemical and physical reactions

2. Innovation of transmission mode: popularize hydraulic and electrical transmission

hydraulic transmission was applied to road rollers in the 1960s, and it has been popularized and popularized in only more than ten years. Now the road roller's walking, vibration, steering and braking systems have achieved full hydraulic transmission. The hydraulic transmission greatly simplifies the design of the transmission and control system of the roller. The hydraulic transmission is stable, the operation is convenient and labor-saving, and it is easy to realize stepless speed regulation and automatic control, which improves the production efficiency and compaction quality of the roller on the whole. Now there are few mechanically driven rollers in the foreign market

hydrostatic transmission technology began to be applied to bulldozers in the 1970s, and soon spread to some small and medium-sized bulldozers and loaders. John Deere company of the United States, caterpillar company, Liebherr company of Germany and Komatsu Manufacturing Institute of Japan all produce and sell full hydraulic bulldozers and loaders. The hydrostatic transmission does not use the hydraulic torque converter, but also omits the separator, service brake and some mechanical transmission mechanisms. It can use the safety valve to realize overload protection of the mechanical and hydraulic system, and give full play to the maximum indexing force with a small indexing power. The remaining power can be used for the auxiliary operation of the machine

Demark company and Liebherr company in Germany took the lead in developing full hydraulic excavators in 1954 and 1955 respectively, but hydrostatic transmission was widely promoted and applied in excavators in the 1970s. Since the beginning of the second process after the 1980s, excavators from large to small are gradually realizing the full hydraulics of driving travel, rotation and excavators. Excavators on the international market have all eliminated various mechanical transmission mechanisms

pavement machinery with a relatively late birth history is dominated by full hydraulic transmission, such as pavers, stabilized soil mixers, pavement milling machines, etc. the stability of hydraulic transmission helps to improve the pavement quality. In rock drilling jumbo and rock drill, hydraulic transmission has replaced the previous pneumatic, and modern wheeled cranes and piling machinery are also developing in the direction of full hydraulics

although the application of electric power in industrial production has a long history, it is rarely used in mobile machinery. First of all, the energy capacity of the motor is small. Compared with the hydraulic motor with the same power, the weight and volume of a motor are many times larger, which brings great difficulties to the spatial layout of the machine. In addition, the efficiency of electric drive is lower than that of express packaging, and the overall safety and stability of FMCG packaging is low, while the consumption of non-ferrous metals is large. However, the electric drive can well realize stepless speed regulation, electric braking and power diversion. The electric drive is more convenient with a minimum of 3 items and is easy to be used on large mining cars, large excavators and large loaders

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