Industrial production developed earlier used excavator, France, Germany, the United States, Russia, Japan is fighting a single bucket capacity 3.5-40m3 a major producer of hydraulic excavators, 80 years from the 20th century began producing large used excavator. For example, the United States mullion company’s capacity 50-150m3 peel bucket excavator, bucket capacity of 132m3 walking Dragline; BE ( – Erie) produced by the walking-style bucket capacity of 168.2m3 Mining Draglines , bucket capacity of 107m3 of stripping excavators, etc., is the world’s largest excavator.

From the late 20th century, the international excavator production to large-scale, micro-oriented, multi-functional specialization and automation direction.

1) The development of used excavator is  more varieties, multi-functional, high quality and efficient. To meet the municipal needs of building construction and farmland abroad fighting capacity of 0.25m3 developed the following mini-excavator, bucket capacity of the smallest only 0.01m3. In addition, the number of most of the medium and small excavators tend to more than one machine can be equipped with multiple working equipment – except shovel, backhoe fitted with a crane, grab, flat slope of the Big Dipper, loading compartments harrow teeth, broken cones, twist drill, electromagnetic chuck, vibrators, bulldozing plate, impact shovel, container fork, high-altitude operation rack, hinged tray and pull shovel so as to meet all construction needs. At the same time, the development of special uses special excavators, such as low specific pressure, low voice sound underwater and amphibious excavator so special.

2) the rapid development of used excavator, continuous improvement and innovation controlling method, the excavator from simple levers to control the development of hydraulic control, pneumatic control, hydraulic servo control and electrical control, radio remote control, computer integrated process control. In hazardous areas or underwater operations using radio control, use of computer controlled laser guidance receivers and combined to achieve a fully automated manipulation excavator operations. All this, all hydraulic excavators of its foundation and create a good premise.

3) to adopt new technologies, new techniques, new structure, speed up the standardization, serialization, universal speed of development. For example, the German company Atlas excavators fitted with new engine speed adjustment device so that excavator according to the most appropriate pace of its operational requirements to work; U.S.company’s new C Series LS-5800 type hydraulic excavator installed automatic control hydraulic system, can automatically adjust the flow, avoid the waste of drive power. Also installed CAPS (computer-aided power system), increase the operating power excavator, hydraulic system to better play the function; Japan’s Sumitomo FJ series produced five new models of excavators equipped with hydraulic circuit connected to computer-aided power control system, using precision control mode selection system, to reduce fuel, engine power and hydraulic power consumption, and the Director of the parts of life; Germany Aojia Kai (O & K) produced excavator pump regulation system has the convergence properties to pump a maximum of efficiency; Japanese steel company in the New God’s 904,905,907,909 Xing intelligent type hydraulic excavator control system adopted even in the absence nigger a practiced driver also do the complex operation Caozuo; Germany Lieb Haier has developed ECO (electronic control operation) of the control device can be adjusted according to operational requirements of the operating performance of excavator to obtain a high efficiency, low fuel consumption results; the United States Jimmy Carter Le Pitt B system in the new excavator on the latest 3114T diesel engine and the torque load sensing pressure system, the power mode selector, to further improve operational efficiency and stability of the excavator. Daewoo DH280 Excavator Company adopted the EPOS — electronic power optimization system, according to engine load changes, automatically adjusting pump power absorbed, so always keep the engine speed near rated speed, that is always full power engine operation, then it will make full use of engine power, improve operational efficiency excavator, but also to prevent the engine stalling due to overload.

4) Update design theory, improve reliability, extend service life. United States, Britain, Japan and other countries promote the use of finite life design theory as an alternative to the traditional theory of the infinite life design and methods, and fatigue damage accumulation theory, fracture mechanics, finite element method, optimal design, electronic computer-controlled electro-hydraulic servo fatigue test technique, fatigue analysis methods of advanced technology in the strength of used excavator, the promotion of the product quality and competitiveness of high efficiency. Dynamic strength of the United States to an examination of dynamic design analysis method, and the creation of forecasts and updates of product failure theory. Hydraulic excavator in Japan has developed the strength component assessment procedures, developed a treatment system reliability accommodation. In the basic theory under the guidance of a large number of tests by means of shortening the new product development cycle, accelerating the process of upgrading the hydraulic excavator, and improve its reliability and durability. For example, hydraulic excavators operating rate of 85% -95%, more than 10,000 hours life.

5) enhancing the driver’s labor protection, improve driver working conditions. Hydraulic excavator with a falling object protective structure and the cab rollover protection structure, the flexibility of installing adjustable seat, with sound measures to reduce noise.

6) to further improve the hydraulic system. Small and medium sized hydraulic excavator hydraulic system changes to a clear trend variable system. Because the variable system in the pump working process, the pressure decreases and increases traffic to Lian, to maintain a constant power hydraulic pump, which pumps equipped with variable hydraulic excavators can regularly make full use of the maximum pump power. When the external resistance increases, a decrease of flow rate (lower rate), so digging force growth rate increases exponentially; by three-loop hydraulic system. Produce three independent effects of each other not a work of movement. To achieve power and back to match the mechanical relay. The third pump connected in other sports on to become an independent open-loop fast into the second movement. In addition, the hydraulic excavator widely used in, for electronic technology, control technology application and promotion of the excavator to create the conditions.

7) The rapid expansion of electronic and automation technology in the excavator. 20th century 70s, to save energy consumption and reduce environmental pollution, so easy to operate excavators and security operations, reduce excavator accent and improve driver working conditions, gradually digging on the use of electronic and automatic control technology. With the excavator’s work efficiency, energy saving, easy operation, safe and comfortable, durable and reliable performance requirements such as the improvement of mechanical and electrical integration prompted the excavator, and it has been a qualitative leap in various properties. 80 years of the 20th century, to microelectronics technology as the core technology, particularly computers, microprocessors, sensors and instrumentation in the excavator, to promote the electronic control technology in the excavator on the application and promotion, and has become the used  excavator important symbol of modernization, the existing excavator advanced with automatic idle speed and throttle the engine control system, power optimization system, the mode of control systems, monitoring systems, electronic control system.