It has been more than 130 years since the first manual excavator came out. During this period, it has experienced the gradual transition from steam-driven semi-rotary excavators to electric-driven and internal-combustion-engine-driven full-rotation excavators, and fully automatic hydraulic excavators using electromechanical-hydraulic integration technology. development process.

The production of excavators in industrially developed countries was earlier. France, Germany, the United States, Russia, and Japan are the main producers of single-bucket hydraulic excavators with a bucket capacity of 3.5-40m³. They have been producing extra-large excavators since the 1980s. For example, the stripping excavator with a bucket capacity of 50-150m³ produced by the American Marion Company, a walking dragline excavator with a bucket capacity of 132m³; Dragline excavators and excavators with a bucket capacity of 107m³ are currently the largest excavators in the world.

Since the late 20th century, the international production of excavators has developed in the direction of large-scale, miniaturized, multi-functional, specialization and automation.

1. Develop multi-variety, multi-functional, high-quality and high-efficiency excavators. In order to meet the needs of municipal construction and farmland construction, micro excavators with bucket capacity below 0.25m³ have been developed abroad, and the smallest bucket capacity is only 0.01m³. In addition, the largest number of medium and small excavators tend to be multi-functional in one machine, and are equipped with a variety of working devices - in addition to front shovel and backhoe, they are also equipped with hoisting, grab bucket, grader bucket, loading bucket, rake Tooth, crushing cone, twist drill, electromagnetic suction cup, vibrator, bulldozer, impact shovel, container fork, aerial work frame, reel and dragline, etc., to meet the needs of various constructions. At the same time, develop special excavators for special purposes, such as low specific pressure, low noise, underwater special and amphibious excavators.

2. The rapid development of full hydraulic excavators, continuous improvement and innovation of control methods, makes excavators develop from simple lever manipulation to hydraulic manipulation, pneumatic manipulation, hydraulic servo manipulation and electrical control, radio remote control, and electronic computer integrated program control. In dangerous areas or underwater operations, radio control is used, and the combination of electronic computer control receivers and laser guidance can fully automate the operation of excavators. All of this, the fully hydraulic excavator has laid the foundation and created a good premise.

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 the German Atlas Company is equipped with a new engine speed adjustment device, which enables the excavator to work at the speed most suitable for its operation requirements; the new C series LS-5800 hydraulic excavator of Lincoln-Belt Company of the United States The machine is equipped with a fully automatic control hydraulic system, which can automatically adjust the flow and avoid the waste of driving power. CAPS (Computer Aided Power System) is also installed to improve the working power of the excavator and better exert the function of the hydraulic system; five new models of FJ series excavators produced by Sumitomo Corporation of Japan are equipped with computer-aided power systems connected to the hydraulic circuit. The power control system uses the precise control mode selection system to reduce the consumption of fuel, engine power and hydraulic power, and prolong the service life of the parts; the oil pump adjustment system of the excavator produced by O&K Company in Germany has the characteristics of confluence , so that the oil pump has the maximum working efficiency; Japan's Kobelco Company adopts an intelligent control system on the new 904.905.907.909 hydraulic excavator, so that even inexperienced drivers can perform complex operations; German Liebherr Company developed The ECO (Electronic Control Operation) operating device can adjust the performance of the excavator according to the operation requirements, achieving high efficiency and low fuel consumption; Caterpillar of the United States adopts the latest 3114T diesel engine and torque on the new B system excavator. Load sensing pressure system, power mode selector, etc., further improve the working efficiency and stability of the excavator. Doosan Construction Machinery Co., Ltd. of South Korea adopts EPOS-electronic power optimization system on the DH280 excavator, which automatically adjusts the power absorbed by the hydraulic pump according to the change of the engine load, so that the engine speed is always kept near the rated speed, that is, the engine always runs at full speed. Power operation, which not only makes full use of the power of the engine, improves the working efficiency of the excavator, but also prevents the engine from stalling due to overload.

4. Update design theory, improve reliability and prolong service life. The United States, Britain, Japan and other countries promote the use of finite life design theory to replace the traditional infinite life design theory and method, and integrate fatigue damage accumulation theory, fracture mechanics, finite element method, optimization design, and electronic computer-controlled electro-hydraulic servo fatigue. Advanced technologies such as test technology and fatigue strength analysis method are applied to the strength research of hydraulic excavators, which promotes the high quality, high efficiency and competitiveness of the products. The United States proposed a dynamic design analysis method to assess dynamic strength, and created a theory for predicting product failure and renewal. Japan has formulated the strength evaluation procedure of hydraulic excavator components, and developed the reliability information processing system. Under the guidance of the above basic theory, with the help of a large number of experiments, the research cycle of new products has been shortened, the process of upgrading hydraulic excavators has been accelerated, and its reliability and durability have been improved. For example, the operation rate of hydraulic excavators reaches 85% to 95%, and the service life exceeds 10,000 hours.

5. Strengthen labor protection for drivers and improve their working conditions. The hydraulic excavator adopts a cab with a falling object protection structure and a tipping protection structure, installs an adjustable elastic seat, and uses sound insulation measures to reduce noise interference.

6. Further improvements to the hydraulic system. The hydraulic system of medium and small hydraulic excavators has an obvious trend of changing to a variable system. Because the variable system uses the increased flow to compensate when the pressure decreases during the working process of the oil pump, so that the power of the hydraulic pump remains constant, that is, the hydraulic excavator equipped with the variable pump can regularly make full use of the maximum power of the oil pump. When the external resistance increases, the flow is reduced (speed is reduced), so that the digging force is doubled; a three-circuit hydraulic system is used. Generates three independent work movements that do not affect each other. To achieve power matching with the slewing mechanism. Turning the third pump on on the other working motion becomes the second independent rapid motion of the open circuit. In addition, hydraulic technology is widely used in excavators, creating conditions for the application and promotion of electronic technology and automatic control technology in excavators.

7. Rapidly expand the application of electronic and automation technology in excavators. In the 1970s, in order to save energy consumption and 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 technology was gradually applied in excavation. With the improvement of performance requirements for excavators in terms of work efficiency, energy saving and environmental protection, easy operation, safety and comfort, reliability and durability, the application of electromechanical-hydraulic integration in excavators has been promoted, and its various performances have made a qualitative leap. . In the 1980s, high-tech centered on microelectronics technology, especially the application of microcomputers, microprocessors, sensors and testing instruments on excavators, promoted the application and promotion of electronic control technology on excavators, and has become an excavator. An important symbol of modernization, that is, the advanced excavation is equipped with electronic control systems such as engine automatic idle speed and throttle control system, power optimization system, working mode control system, and monitoring system.