Wheel Loader basic knowledge
Loaders are mainly used for shoveling, loading, unloading, transporting soil and stone materials such as scattered materials, and can also carry out a light shovel operation for rock and hard soil. If the different working equipment is changed, the work of pushing soil, lifting and loading and unloading other materials can be completed. In the highway construction, it is mainly used for the filling and digging of the subgrade engineering, the aggregate and loading of the asphalt and the cement concrete yard. Because of its advantages of fast operation speed, good maneuverability and light operation, it has developed rapidly and became the main machinery in the construction of earth and stone.
The commonly used single bucket loaders are classified according to the power of the engine, the form of transmission, the structure of the walking system and the way of loading.
a. Engine power:
(1) the power is less than 74kw as a small loader.
(2). The power in 74-147kw is a medium loader
(3) power in 147-515kw for large loader
(4). Power more than 515kw is a special large loader
b. Transmission form:
(1) hydraulic mechanical transmission, small impact and vibration, long life of transmission parts, convenient operation, automatic adjustment between vehicle speed and load, generally used in medium and large loaders.
(2) hydraulic transmission: can be stepless speed control, control between the stool, but the start-up is poor, generally only on the small loader.
Power transmission: stepless speed regulation, reliable work, simple maintenance, high cost, generally used in large loaders.
3. Walking structure:
a.Tyre type: light quality, fast speed, flexible maneuver, high efficiency, difficult to damage road surface, high ground ratio pressure, poor pass, but widely used.
b. Crawler type: small grounding ratio, good pass through, low center of gravity, good stability, strong adhesion, large traction force, big cutting force, low speed, poor flexibility, high cost, and easy to damage road surface when walking.
4. Loading and unloading methods:
a. Front unload: simple structure, reliable work, good field of vision, suitable for various operating sites, a wide range of applications;
b. rotary type: the working device is installed on the turntable with slewing 360O, the side unloading does not need to turn around, the operation efficiency is high, but the structure is complex, the quality is large, the cost is high, and the side stability is bad, so it is suitable for the less competitive field.
c. Back unloading type: front end loading, rear end unloading, high efficiency and poor safety of operation.
The development of loader technology in the international market is the United States, Japan and the European Union. The United States is the world's largest producer of loaders. Its market is mainly known for high-end products. There are more than 40 manufacturing enterprises, including Caterpillar, Clark, Dreiser, diel, Le Turle and Keith. Japan is the second largest producer of loaders, with an annual output of about 40 thousand. The main manufacturer: Komatsu, Toyo, MITSUBISHI, Caterpillar new haulage machine Kawasaki heavy industries, the ancient river etc.. The EU is the third largest group of loader production, it has Italy's ARIS, Sweden's Volvo (VME group), Germany O&K, Liebherr, delizete Mei, British JCB and other famous company. Today, the main enterprises of the three major groups have infiltrated into the Chinese loader market in stages, especially the large equipment in key domestic projects.
The development of the loader in China:
China's loader started at the end of 1960, and its development has gone through the stage of imitation in 60s, the stage of self reliance in 70s, and the stages of technology introduction, joint venture cooperation and self development after 80s.
In the early days of our first production loader is mechanical crawler loader Z1-4 type 4T (Chengdu engineering machinery factory production of 1 cubic meters) and star loader (Shanghai port machinery factory production) and later Z420, 2T hydraulic loader (Chengdu engineering machinery factory) and Z4353.5t loader (Xiamen engineering machinery factory Liuzhou engineering machinery factory production), and developed a rotary China loader Z4H2 type 2T, 180 degree rotation of the loader (Chengdu engineering machinery factory).
In the middle of 1960s, the Z435 type is the whole frame and the rear axle. After several years of efforts, based on absorption of wheeled loader when the world's most advanced technology, the successful development of the 162KW power shovel type wheel loader, setting Z450 (later ZL50), and in December 18, 1971 formally identified by experts, so the birth of our first articulated wheel the loader, thus creating the Chinese loader industry formation and development history.
The Z450 loader has the basic structure of modern wheel loaders, such as hydraulic mechanical transmission, power shift, double bridge drive, hydraulic control, articulated power steering and pneumatic push brake. It is the advanced level of the world at that time. It also basically represents the basic structure of the first generation wheel loading in China. This machine in terms of overall performance has good dynamic performance, high breakout force, the insertion force has flexible and convenient operation, high operation efficiency and a series of advantages.
In 1978, according to the requirements of the machinery department, the Institute worked out a series of Chinese wheel loaders based on the Liugong Z450. Making standard time, keep Z on behalf of the loader (loading, Zhuang Pinyin initials), replace "4" on behalf of L (Lun wheeled round, Pinyin initials), Z450 ZL50, it worked out in China to ZL wheeled Liugong ZL50 based type loader series standard this is our country carrying a major turning point in the history of the development of the machine. The standard setting out at the industry division of labor, Liugong, Xiagong manufacturing ZL40 above large and medium-sized wheeled loaders, as workers, should work the manufacturing of ZL30 in the small wheel loader, Liugong, gradually formed into four large loaders, Xiamen Engineering Enterprise and industry should work at that time.
By the end of 70s and early 80s, the loader manufacturing enterprises in China have increased to more than 20, and the loader industry in China has been initially formed. When the wheel loader has developed to the third generation, the basic structure of the wheel loader in China is still developed by the Z450 (ZL50). The change of the second generation is not very large, and the change of the third generation is slightly larger.
From the point of view of product structure, China's loader models are mainly concentrated in 3T, including 3.5t, 4T and 5T. By 2005, the market share of 3 to 5T level has reached over 97%. Especially the 5T models of the most concentrated, the market share reached 60% (mainly to seize the 4T level and the minicomputer market share); 3T products these years market share are hovering around 30%, not much change; 6T or above, especially large tonnage machine more than 8t level. Domestic products are not mature, mainly the use of imported products or joint ventures and foreign-funded enterprises.
In addition, according to the current market situation analysis, the 3 ~ 5T loader in the next few years will still be the main model of market sales as a mature product. 6 ~ 10t of domestic products only Liugong, XCMG and ha, a few enterprises have formed paper products and technologies, if these enterprises make a breakthrough in technology, cost, price and reliability, market prospects.
The main current domestic production loader enterprises Guangxi Liugong, Fujian Lonking, Fujian Liteng, Shandong, XCMG, Chang Lin, Foton heavy industry, after all enterprises to independent research and development, reform and innovation, the loader gradually became an important representative of national mechanical products, has made remarkable achievements.