In the early days of the founding of New China, the production history of excavators in China began with the mapping and imitation of mechanical single bucket excavators in the 1930s and 40s of the former Soviet Union, such as W50 1. W502.W 1。 W 1002。 Due to the need of national economic construction at that time, more than ten excavator manufacturers were established successively. From 65438 to 0967, China independently developed hydraulic excavators. The products successfully developed in the early stage mainly include WYl00 from Shanghai Construction Machinery Factory, W4-60 from Guiyang Mining Machinery Factory and WY60 excavators from Hefei Mining Machinery Factory. Followed by the Yangtze River excavator factory WYl60 excavator and Hangzhou heavy machinery factory WY250 excavator. They have taken an extremely important step for the formation and development of the hydraulic excavator industry in China.
By the end of 1980s, there were more than 30 excavator manufacturers in China, producing more than 40 models. Small and medium-sized hydraulic excavators have formed a series, with bucket capacity of 0. 1 ~ 2.5 m3 and 12, with more than 20 models. They also produce 0.5 ~ 4.3 m3, 10 m3 and 12 m3 mechanical transmission single bucket excavators, 1 m3 tunnel excavators and 4 m3 long arm excavators for large mines. 1000m3 /h bulldozer, etc. , and developed a marine hydraulic excavator with bucket capacity of 0.25m3, bucket capacity of 0.4m3, 0.6m3 and 0.8m &; Sup3 amphibious excavator, etc. But generally speaking, the production batch of excavators in China is small and scattered, and the production technology and product quality are far behind the international advanced level.
Since the reform and opening up, we have actively introduced, digested and absorbed foreign advanced technology, which has promoted the development of excavator industry in China. Among them, Guiyang Mining Machinery Factory, Shanghai Construction Machinery Factory, Hefei Mining Machinery Factory and Changjiang Excavator Factory introduced A9 12 manufacturing technology respectively. R9 12。 R942。 A922。 R922。 R962。 R972。 Liebherr's R982 hydraulic excavator. In the following years, Hangzhou Heavy Machinery Factory imported the production technology of H55 and H85 hydraulic excavators from German Demag Company, and Beijing Construction Machinery Factory imported the manufacturing technology of German oga Cai(0 &:K)RH6 and MH6 hydraulic excavators. At the same time, Shandong Bulldozer General Factory (whose excavator production base was renamed as Shanzaiji Co., Ltd., including Qiangdahe brand), Yellow River Construction Machinery Factory, Jiangxi Changlin Machinery Factory and Shandong Linyi Construction Machinery Factory have jointly introduced PC 100 and PC 120. PC200，PC220。 PC300 and PC400 hydraulic systems produced by Komatsu, Japan. After several years of digestion, absorption and transplantation of imported technology, these factories have improved the performance index of domestic hydraulic excavators to the international level in the 1980 s, and the output has also increased year by year. Due to the increasing and diversified domestic demand for hydraulic excavators, the product structure adjustment of large and medium-sized state-owned enterprises has affected some other machinery manufacturers to join the hydraulic excavator industry.
Insiders pointed out that China single bucket hydraulic excavator should develop in the direction of full hydraulic pressure; The bucket capacity should be controlled at 0.1-15m & sup3; ; However, for large-scale multi-bucket excavators, mechanical type is still the main one because of the high requirements of manufacturing and assembly accuracy of hydraulic components and poor maintenance conditions on the construction site. In order to realize the automation of hydraulic excavator operation, it is necessary to study and apply electro-hydraulic control technology.
develop
China began to develop excavator products in the late 1960s. After just over 40 years, especially over 30 years of reform and opening up, China's excavator manufacturing industry has developed rapidly. According to the data of National Bureau of Statistics, in 20 10, there were 252 excavator manufacturing enterprises above designated size in China, with sales of1697.85 billion yuan, product sales profit of 25.367 billion yuan, and total profit of 2 1406 billion yuan, with a year-on-year increase of over 80%.
China's excavator market is growing at an average rate of 30%, becoming one of the largest markets in the world. Judging from the development situation, China is at the peak of infrastructure construction in road traffic, energy and water conservancy and urban construction, and the market demand for excavators is increasing year by year. In 20 10, the actual cumulative sales of excavators in China exceeded165,000, up 74.5% year-on-year.
At the end of 20 10, major domestic enterprises have expanded the production capacity of excavators, and other enterprises have also opened up excavator models in an attempt to drive the profit growth of enterprises through the rapid growth of excavator market. In fact, there are both risk factors and income considerations. Because bank credit did not actively promote the construction of affordable housing, the sales of construction machinery market shrank indirectly in the second quarter of 201/kloc-0. 20 1 1 May, domestic sales of excavators 13956, down 12.4% year-on-year, and now it is down in the first month of that month; During the period of1-May, the cumulative sales volume was 1 15589 units, up by 38. 1% year-on-year, and down by 12 percentage points compared with the period of1-April.
The data shows that from 20 1 1 to May, the market share of domestic brands has further increased to 37%. Sany Heavy Industry, which ranks first in domestic excavator production capacity, has reached the scale of annual production and sales of tens of thousands of excavators, and the production capacity of the top four in the industry has reached the level of more than 4,000 excavators/year. The capacity expansion speed of other enterprises is also quite strong. In the next stage, domestic brand excavators may occupy the market share of imported machines and second-hand phones.
According to the data disclosed by construction machinery online, as of September 20 14, the sales volume of mini excavators under 6 tons was 1006, of which the market share of foreign brands was 55.0% and that of domestic brands was 45.0%. In addition, the sales volume of excavators over 6 tons is 3 139, the market share of foreign brands is 6 1.0%, and the market share of domestic brands is only 39.0%. According to the data of Sany Heavy Industry, the domestic market share of the company's excavators reached 1 1.56%, 15.8% and 13.7% in 20 13 years respectively. In the first half of this year, its market share once again exceeded 15%. The insiders believe that the company won the first place this year, and there is no suspense in achieving the "four-year sales champion".
On the whole, the number of excavators in China is low, but the product price is high. Sales methods are mainly financial leasing or bank mortgage. Once the credit is relaxed, the sales of excavators will be the best products. It can be predicted that in 20 1 1-20 13 years, with the economic recovery of China and the acceleration of real estate and urbanization construction, the sales of excavators of various tonnage will continue to increase. After deducting the uncertainties, each tonnage excavator will exceed 60 1-20 13.
With the intensification of competition in excavator manufacturing industry, mergers, acquisitions, integration and capital operation among large excavator manufacturing enterprises are becoming more and more frequent. Excellent domestic excavator manufacturers pay more and more attention to the research of the industry market, especially the in-depth study of the industry development environment and product buyers. Because of this, a large number of domestic excellent excavator brands have risen rapidly, and gradually become the leader in the excavator manufacturing industry in China and even the world! It has been more than 130 years since the first manual excavator came out. During this period, it has experienced a gradual development process from a semi-rotary excavator driven by steam to a fully rotary excavator driven by electric power and internal combustion engine, as well as a fully automatic hydraulic excavator with electromechanical and hydraulic integration technology.
Excavators were produced earlier in industrialized countries. France, Germany, the United States, Russia and Japan are the main producers of 3.5-40 m3 single bucket hydraulic excavators, and super-large excavators have been produced since 1980s. For example, the stripping excavator with bucket capacity of 50- 150 m3 and the walking shovel excavator with bucket capacity of 132 m3 produced by Marion Company in the United States; B-E (Sai Bu Lu Si-Yili) Co., Ltd. produces a walking shovel excavator with a bucket capacity of 168.2 m3 and a stripping excavator with a bucket capacity of 107 m3, which is the largest excavator in the world at present.
Since the late 20th century, the international excavator production has developed towards large-scale, miniaturization, multifunction, specialization and automation.
1) Develop multi-variety, multi-functional, high-quality and efficient excavators. In order to meet the needs of municipal construction and farmland construction, foreign countries have developed mini excavators with bucket capacity below 0.25 m3, and the minimum bucket capacity is only 0.0 1 m3. In addition, the largest number of small and medium-sized excavators often have multiple functions. They are equipped with a variety of working devices-in addition to front shovels and backhoes, they are also equipped with cranes, grab buckets, flat slope buckets, loading buckets, harrows, crushing cones, twist drills, electromagnetic suction cups, vibrators, bulldozers, impact shovels, pallet forks, aerial work stands, reamers and shovels. Meet the requirements. At the same time, develop special-purpose excavators with low specific pressure, low noise, underwater special excavators and amphibious excavators.
2) Rapid development of fully hydraulic excavators, continuous improvement and innovation of control methods, so that excavators develop from simple lever control to hydraulic control, pneumatic control, hydraulic servo control and electrical control, radio remote control and computer integrated program control. When working in dangerous areas or underwater, radio control, electronic computer control receiver and laser guidance are combined to realize the complete automation of excavator operation control. All these have laid a foundation and created a good premise for the full hydraulic excavator.
3) Attach importance to the adoption of new technologies, new processes and new structures, and accelerate the development of standardization, serialization and generalization. For example, the excavator produced by Atlas Company in Germany is equipped with a new engine speed regulating device, which makes the excavator work at the speed most suitable for its operation requirements; The new C-series LS-5800 hydraulic excavator of Lincoln-Burt Company in the United States is equipped with a fully automatic hydraulic control system, which can automatically adjust the flow and avoid the waste of driving force. CAPS (Computer Aided Power System) is also installed to improve the working power of the excavator and give full play to the function of the hydraulic system. Five new models of FJ series excavators produced by Sumitomo Corporation of Japan are all equipped with computer-aided power control system connected with hydraulic circuit, and adopt fine control mode selection system to reduce the consumption of fuel, engine power and hydraulic power and prolong the service life of parts. Germany oga kai(o & amp；; K) The oil pump regulating system of the excavator produced by our company has confluence characteristics, which makes the oil pump have the maximum working efficiency; Intelligent control system is adopted in the new 904.905.907.909 hydraulic excavator of Japan Kobelco, and even inexperienced drivers can perform complex operations. Liebherr Company in Germany has developed an ECO (Electronic Control Operation) control device, which can adjust the working performance of excavators according to the working requirements, achieving high efficiency and low fuel consumption. The latest 3 1 14T diesel engine, torque load sensing pressure system, power mode selector, etc. It has been adopted by Caterpillar's new B-system excavator, which further improves the working efficiency and stability of the excavator. Korea Doosan Construction Machinery Company adopted EPOS- electronic power optimization system on DH280 excavator. It automatically adjusts the power absorbed by the hydraulic pump according to the change of engine load, so that the engine speed is always near the rated speed, that is, the engine is always running at full power, which not only makes full use of the engine power, improves the working efficiency of the excavator, but also prevents the engine from stalling due to overload.
4) Update design theory to improve reliability and prolong service life. The United States, Britain, Japan and other countries promoted the finite life design theory to replace the traditional infinite life design theory and method, and applied advanced technologies such as fatigue damage accumulation theory, fracture mechanics, finite element method, optimal design, electro-hydraulic servo fatigue test technology controlled by computer and fatigue strength analysis method to the strength research of hydraulic excavators, which promoted the quality, efficiency and competitiveness of products. The United States put forward a dynamic design analysis method to evaluate dynamic strength, and established a theory to predict product failure and renewal. Japan has made a strength evaluation plan for hydraulic excavator parts and developed a reliability information processing system. Under the guidance of the above basic theory, with a lot of experiments, the research cycle of new products has been shortened, the upgrading process of hydraulic excavators has been accelerated, and its reliability and durability have been improved. For example, the operating rate of hydraulic excavators reaches 85% ~ 95%, and the service life exceeds 6,543.8+0,000 hours.
5) Strengthen the labor protection of drivers and improve their working conditions. The hydraulic excavator adopts the cab with falling object protection structure and tipping protection structure, installs adjustable elastic seats, and adopts sound insulation measures to reduce noise interference.
6) Further improve the hydraulic system. The hydraulic system of small and medium-sized hydraulic excavators has an obvious trend of changing to variable system. Because the variable system is compensated by increasing the flow rate when the pressure drops during the operation of the oil pump, the power of the hydraulic pump remains unchanged, that is, the hydraulic excavator equipped with the variable pump can always make full use of the maximum power of the oil pump. When the external resistance increases, the flow decreases (the speed decreases), which doubles the excavation force; Three-loop hydraulic system is adopted. Produce three independent working movements that do not affect each other. And the power matching with the slewing mechanism is realized. Turn on the third pump in other working movements, which becomes the second independent rapid movement in the open loop. In addition, the wide application of hydraulic technology in excavators has created conditions for the application and popularization of electronic technology and automatic control technology in excavators.
7) Rapidly expand the application of electronics and automation technology in excavators. In 1970s, in order to save energy consumption, reduce environmental pollution, make the operation of excavators light and safe, reduce the noise of excavators and improve the working conditions of drivers, electronic and automatic control technologies were gradually applied to excavation. With the improvement of working efficiency, energy saving, environmental protection, operability, safety, comfort, reliability and durability of excavators, the application of mechatronics in excavators has been promoted, and its performance has made a qualitative leap. In 1980s, high-tech with microelectronics as the core, especially the application of microcomputers, microprocessors, sensors and detection instruments in excavators, promoted the application and popularization of electronic control technology in excavators, and has become an important symbol of excavator modernization, that is, advanced excavators are equipped with electronic control systems such as engine automatic idling and throttle control system, power optimization system, working mode control system and monitoring system.
8) Pay more attention to environmental protection. Caterpillar, Komatsu and other manufacturers have introduced excavators that meet the three-level emission requirements.