Loader details daquan

Loader is a kind of earthwork machinery, which is widely used in highway, railway, construction, hydropower, port, mine and other construction projects. Mainly used for bulk materials such as shovel, sand, lime and coal. , but also light shovel light mining materials and hard soil. Replacing different auxiliary working devices can also be used for bulldozing, lifting and loading and unloading wood and other materials.

In road construction, especially in high-grade highway construction, loaders are used for filling and excavation of subgrade engineering, aggregate and loading of asphalt mixture and cement concrete yard. In addition, it can also carry out operations such as bulldozing, leveling and towing other machinery. Loader has become one of the main types of earthwork construction in engineering construction because of its advantages of fast working speed, high efficiency, good maneuverability and easy operation.

Chinese name: loader mbth: date of invention of loader: 1929 Power: engine application scope: main functions of engineering construction: loading and unloading forklift industry: development history of construction machinery, main components, working devices, development trend, classification, use, selection principle, sales demand, daily maintenance, running-in period, use and maintenance, operation procedures and development history of China loaders. It is particularly commendable and proud that the annual production and sales of loaders have exceeded 6.5438+0.6 million units. In today's China market with numerous international brands, domestic brand loaders still occupy the vast majority of the market. 1978, the annual output of loaders in China was only 13 15, and the cumulative output was only 9454. In 2007, the sales volume exceeded 1 60,000, and the export volume alone exceeded110,000, exceeding the historical cumulative output before the reform and opening up. Similarly, in 1978, the annual output of bulldozers in China was only 1909, and the cumulative output was 1 1923. At that time, imports were relatively large. By 1980, the cumulative import volume reached 3333 units, especially in the late 1980s, accounting for nearly 30% of the market. In 2007, the sales volume of bulldozers exceeded 7390, which not only occupied most of the domestic market, but also exported in large quantities. In 2007 alone, the export volume reached 2,065, exceeding the total output of bulldozers in China from 65,438 to 0,978. Industry Development After nearly 50 years' development, especially the ultra-high-speed development in recent 10 years, the technical quality of China loader industry has been greatly improved, and the gap with the world advanced level is getting smaller and smaller. 20 1 1 year, the loader industry in China sold a total of 192 100 sets, up 14.4438+0% year-on-year. Among them, the domestic market sold loaders 17327 1, with a year-on-year increase of10.80%; A total of 18829 loaders were exported, up 72.25% year-on-year, and the growth rate of export was much higher than that of domestic sales. 20 1 1 In the first three quarters, there was a great demand for loaders in East China and North China, in which the sales of loaders in East China accounted for 2 1.7% of the national sales and that in North China accounted for 19.0%. In terms of products, in the first three quarters of 20 1 1, 5T products had the largest market share, accounting for 66.78%, which was 2.88 percentage points lower than that of 20 10, followed by 3T products with a market share of 22.57%, which was 2 percentage points higher than that of 20 10. According to statistics, during the "Twelfth Five-Year Plan" period, China's fixed assets investment in the whole society will still maintain a relatively high growth rate, with a growth rate of around 20%. The state will further intensify the construction of affordable housing, water conservancy projects, marine construction projects, railways, highways, urban public transportation and infrastructure, electric power, gas transmission projects and electric power transmission projects. It is estimated that by 20 15, the sales volume of loader industry in China will reach 300,000 units, of which 40,000 units will be exported. The loader industry in China has a bright future. China modern wheel loader started from Z435 in the mid-1960s. The machine is an integral frame, and the rear axle rotates. After several years' efforts, on the basis of absorbing the most advanced wheel loader technology in the world at that time, a shovel-connected wheel loader with the power of 162KW was successfully developed, which was finally finalized as Z450 (later ZL50) and officially passed the expert appraisal in February1971kloc-0/8. In this way, the first articulated wheel loader in China was born, thus creating the history of the formation and development of the loader industry in China. Z450 loader has the basic structure of modern wheel loader, such as hydraulic mechanical transmission, power shift, dual-shaft drive, hydraulic control, articulated power steering, pneumatic afterburner braking, etc. , is the advanced level of the world at that time. It also basically represents the basic structure of the first generation wheel loader in China. The machine has a series of advantages in overall performance, such as good power, strong digging force, flexibility, light operation and high work efficiency. During the period of 1978, Tiangong Institute formulated a series of standards for wheel loaders in China based on Liugong Z450 according to the requirements of the Ministry of Machinery. When making standards, Z stands for loader, L stands for wheel instead of "4", and Z450 is changed to ZL50. Therefore, based on Liugong ZL50, a series of China ZL wheel loader standards have been formulated, which is a major turning point in the history of loader development in China. After the standard was formulated, according to the division of labor at that time, Liugong and Xiagong manufactured large and medium-sized wheel loaders above ZL40, and Chenggong and Gong Yi manufactured small and medium-sized wheel loaders below ZL30, which gradually formed the four backbone enterprises of loaders at that time. By the end of 1970s and 1980s, the number of loader manufacturers in China had increased to more than 20, initially forming the loader industry in China. China wheel loader has developed to the third generation, but the most basic structure is still evolved from Z450(ZL50). The second generation has not changed much, and the third generation has not changed much. In 200 1 year, the total sales volume of loaders in the whole industry in China has exceeded 30,000, ranking in the forefront of the world loader market. Therefore, China has become a big producer and exporter of loaders in the world. In 2006, the total sales volume of China loader industry was 129793, and in 2005 it was 1 12527, with a year-on-year increase of 15.3% and a net increase of 17266, which exceeded the level of China loader industry before the Eighth Five-Year Plan. In 20071-1/month, the cumulative sales volume of 26 major enterprises of loaders was 143794, an increase of 34397 vehicles over the same period last year (109397 vehicles), with an increase of 31. The cumulative export volume was 8,606 sets, accounting for 6.0% of the cumulative sales volume, an increase of 5,372 sets over the previous year (3,234 sets), with an increase of 166. 1%. In 2008, the growth momentum of China loader industry continued unabated. From June to July, the cumulative sales volume of loaders nationwide was 120449, a year-on-year increase of 30.5%. With the development of loader industry in China, some problems are increasingly exposed. In particular, the entry threshold of the industry is extremely low, vicious price competition leads to low profitability of enterprises, lack of marketing concepts, difficulties in market expansion, poor product quality and reliability, and aging product and organizational structure, which restricts the further development and quality improvement of the industry. Therefore, China loader enterprises must seize the new development situation, embody the differentiation strategy and cost leadership strategy in product research and development, continue to strengthen the construction of scientific research and development system with national technology centers, universities and research institutes as the main body, build value chain marketing, strengthen brand building and enhance brand value. Only in this way can they be invincible in the new situation. The main components include engine, torque converter, gearbox and front and rear drive axles, which are referred to as four parts: 1. Engine two. There are three pumps on the torque converter, namely the working pump (supplying lifting and tipping pressure oil) and the steering pump (supplying steering pressure oil). Variable speed pump is also called walking pump (supplying pressure oil for torque converter and gearbox), and some models are also equipped with pilot pump (supplying pilot pressure oil for control valve). Working pump, multi-way valve, lifting cylinder and tipping cylinder. 4. Traveling oil circuit: gearbox oil pan, traveling pump and gearbox clutch. 5. Drive: transmission shaft, main differential and wheel side reducer. 6. Steering oil circuit: oil tank, steering pump, flow stabilizing valve (or priority valve) steering cylinder. 7. The gearbox is integrated (planetary) and split. The working device of loader consists of bucket 1, boom 2, connecting rod 3, rocker arm 4, bucket cylinder 5 and boom cylinder 6. The whole working device is hinged on the frame 7. The bucket is hinged with the bucket cylinder through a connecting rod and a rocker arm for loading and unloading materials. The boom is hinged with the frame and boom cylinder to lift the bucket. The overturning of the bucket and the lifting of the boom are controlled by hydraulic pressure. When the loader is working, the working device should be able to ensure that: when the bucket cylinder is locked and the boom cylinder rises or falls, the linkage mechanism makes the bucket translate up and down or nearly translate to prevent the bucket from tilting and material scattering; When the boom is in any position and the bucket rotates around the hinge point of the boom for unloading, the inclination angle of the bucket is not less than 45, and the bucket can be leveled automatically when the boom descends after unloading. There are seven structural types of loader working devices at home and abroad, which are divided into three bars, four bars, five bars, six bars and eight bars according to the number of linkage mechanisms. According to whether the input and output rods turn in the same direction, they can be divided into forward and reverse linkage mechanisms. The bucket structure of loaders used in earthwork is usually welded with low-carbon, wear-resistant and high-strength steel plates, with wear-resistant medium-manganese alloy steel as the cutting edge and high-strength and wear-resistant steel as the side cutting edge and reinforcing corner plate. There are four shapes of bucket cutters. The selection of tooth profile should consider factors such as insertion resistance, wear resistance and easy replacement. Tooth shapes are divided into sharp teeth and blunt teeth. Most tire loaders use sharp teeth, while crawler loaders use blunt teeth. The number of bucket teeth depends on the bucket width, and the bucket tooth spacing is generally 150-300mm. The structure of bucket teeth can be divided into two types: integral and split. Small and medium-sized loaders mostly adopt integral type, while large loaders often adopt split type because of poor working conditions and serious wear of bucket teeth. Split bucket teeth are divided into two parts: basic tooth 2 and tooth tip 1, and only the tooth tip needs to be replaced after wear. The development trend of domestic wheel loaders is shifting from low level, low quality and low price to high level, high quality, medium price and economy. In the transition from imitation to independent development, major manufacturers have continuously invested in technology, adopted different technical routes, and made innovations in key components and systems, thus getting rid of the current situation that product designs are similar and have no own characteristics and advantages, emerging from the vicious circle of low-level disorderly competition and becoming the leader of loader industry. (1) The development of large and small wheel loaders is limited by objective conditions and total market demand. The most competitive medium-sized loaders will be updated faster and faster. (2) According to the actual situation of each manufacturer, redesign the overall design, optimize various performance indexes, strengthen the strength and stiffness of structural parts, and greatly improve the reliability of the whole machine. (3) Refine the system structure. Such as vibration reduction of power system, structural optimization of heat dissipation system, performance index optimization of working device, dust prevention of hinge point, industrial modeling design, etc. (4) Using electronic technology and load sensing technology to realize the automatic gear shifting of gearbox and the application of hydraulic variable system, so as to improve efficiency, save energy and reduce the operating cost of loader. (5) Improve safety and comfort. The cab is gradually equipped with fops & amp； ROPS function, the environment in the cab will be close to the direction of the car, and the steering wheel, seat and joystick can be adjusted to make the operator work in place. (6) Reduce noise and emissions and strengthen environmental protection indicators. With the enhancement of people's awareness of environmental protection, it is urgent to reduce the noise and emissions of loaders. Many big cities have formulated motor vehicle noise and emission standards. If the construction machinery does not meet the emission standards, it will be restricted to be sold in this area. (7) Widely adopt new materials, new processes and new technologies, especially the integration technology of machinery, electricity and liquid to improve the service life and reliability of products. (8) Simplify maintenance as much as possible, minimize maintenance times and time, increase maintenance space, widely adopt electronic monitoring and monitoring technology, further improve the fault diagnosis system, and provide drivers with ways to eliminate problems. Commonly used single bucket loaders are classified according to engine power, transmission form, walking system structure and loading mode. 1, engine power: ① power less than 74kw is a small loader. ② The power of medium loader is 74 ~147 kW; ③ The power of the large loader is147 ~ 515kW; (4) the power of the super-large loader is greater than 515kw; 2. Transmission form: ① Hydraulic-mechanical transmission, with small impact vibration, long transmission life, convenient operation, automatic adjustment of vehicle speed and external load, generally used in medium and large loaders. ② Hydraulic transmission: stepless speed regulation, simple operation, but poor starting performance, generally only used on small loaders; ③ Electric drive: stepless speed regulation, reliable operation, simple maintenance and high cost, generally used for large loaders. 3. Walking structure: ① Tire type: light weight, high speed, flexibility, high efficiency, difficult to damage the road surface, large grounding pressure, poor passability, but widely used; ② Crawler type: small grounding specific pressure, good passability, low center of gravity, good stability, strong adhesion, large traction, large specific cutting force, low speed, relatively poor flexibility, high cost, and easy to damage the road surface when walking. 4. Loading and unloading mode: ① Front-loading type: simple structure, reliable operation and good vision, suitable for various workplaces and widely used; (2) Rotary type: the working device is installed on a turntable that can rotate 360 degrees, so it is not necessary to turn around and unload sideways, which has high working efficiency, but it has complex structure, large mass, high cost and poor lateral stability, and is suitable for smaller sites. ③ Rear unloading type: front loading and rear unloading, with high working efficiency and poor working safety. Purpose Loaders are mainly used for shoveling, loading, unloading, earth moving, stone moving and other bulk materials, and can also shovel and dig rocks and hard soil lightly. If you change different working devices, you can also complete the work of bulldozing, lifting and loading and unloading other materials. In highway construction, it is mainly used for the filling and excavation of subgrade engineering, the loading of aggregate and asphalt and cement concrete yards. Because it has the advantages of fast working speed, good maneuverability and easy operation, it has developed rapidly and become the main machinery in earthwork construction. Selection principle 1. Model selection: it is mainly selected and determined according to the operation occasion and purpose. Generally, operations are carried out in quarries and soft bases, and tire loaders are often used in conjunction with snow chains; 2. Power selection: diesel engines are generally used in construction machinery, and special plateau diesel engines should be used when working in special areas, such as places above 3000m above sea level; 3. Selection of transmission type: Hydromechanical transmission is generally selected. Among them, the key component is the choice of torque converter form. Most loaders produced in China use double turbines and single-stage two-phase hydraulic torque converters. 4. When selecting a loader, the braking performance of the loader should be fully considered, including multiple in-service braking, parking braking and emergency braking. There are three kinds of brakes: hoof type, clamp type and wet multi-disc. The driving mechanism of brake generally adopts afterburner, and its power source is compressed air, gas cap oil and hydraulic pressure. Air-top oil braking system is commonly used. In order to improve driving safety, double-loop braking system is generally adopted. Sales Demand In 20 13 years, the loader market was relatively depressed, and the production and sales volume declined to varying degrees year-on-year. The data shows that the total sales volume of loaders in the first quarter was 4 1486, down 19.0% year-on-year. Among them, the sales volume in February was low, which not only decreased by 54. 1% year-on-year, but also decreased by 6. 1% quarter-on-quarter. Sales rebounded sharply in March, down 6.6% year-on-year and up 20 1.2% quarter-on-quarter. It can be seen that the future of the loader market will also be expected. In April, loaders also achieved positive growth year-on-year. In May, the sales volume of loaders reached 19045 units, up 14% year-on-year, higher than 4% in April. 32% of the domestic market demand for loaders comes from mining, 33% from infrastructure construction, 14% from water conservancy construction and 8% from real estate. The development of these industries largely depends on the domestic investment level in fixed assets. In the first half of 20 13, China's fixed assets investment (excluding farmers)18131800 million yuan, and the cumulative growth rate of fixed assets investment was 20. 1%, continuing the steady growth trend. In the second half of the year, there will be no major changes in the internal and external factors that determine the investment trend. Therefore, the central government will continue to strengthen the regulation and control of investment, while maintaining the investment growth rate of about 20%, the investment structure will be further optimized. We predict that the infrastructure investment will go smoothly in the second half of 20 13, and the mining industry will get out of the downturn under the control of * * * and enterprises. During the Twelfth Five-Year Plan period, the state will invest/kloc-0.8 trillion yuan in water conservancy, and the real estate industry will gradually get out of the current chaotic situation under the coordination of * * * and real estate developers. Therefore, under the joint action of many factors, the loader industry will gradually pick up the construction machinery industry under the appropriate control of the enterprise itself. After the daily maintenance loader leaves the factory, it is generally stipulated that there is a running-in period of about 60 hours (some are called running-in period), which is stipulated according to the technical characteristics of the loader at the initial stage of use. Running-in period is an important link to ensure the normal operation of loader, reduce failure rate and prolong service life. Some users ignore the special technical requirements of the new machine's running-in period because they lack the common sense of loader use or because the construction period is tight or they want to get benefits as soon as possible. Some users even think that the manufacturer has a warranty anyway, and the broken machine is repaired by the manufacturer, so the machine is overloaded for a long time during the running-in period, which leads to frequent early failures of the machine, which not only affects the normal use of the machine, shortens the service life of the machine, but also affects the project progress because of the damage of the machine. Therefore, we should pay full attention to the use and maintenance of loaders during the running-in period. Due to the influence of processing, assembly and adjustment of new machine parts, the friction surface is rough, the contact area of the mating surface is small, and the surface stress is uneven. During the operation of the machine, the concave and convex parts on the surface of the parts are embedded in friction with each other, and the worn metal chips continue to participate in friction as abrasives, further accelerating the wear of the mating surfaces of the parts. Therefore, parts (especially mating surfaces) are easy to wear during the running-in period and wear quickly. At this time, if the work is overloaded, it may lead to damage and early failure of parts. Poor lubrication It is difficult to ensure the uniformity of the fit clearance because of the small fit clearance of newly assembled parts and assembly, and it is difficult for lubricating oil (grease) to form a uniform oil film on the friction surface to prevent wear. Thereby reducing the lubrication efficiency and leading to early abnormal wear of components. In severe cases, it will cause scratches or bite marks on the friction surface with precision, which will lead to failure. There is a deviation between the geometric shape and the fitting size of the loose newly machined and assembled parts. At the initial stage of use, due to the impact, vibration and other alternating loads, as well as the influence of heating, deformation and other factors, the wear is rapid, and it is easy to loosen the originally fastened parts. Leakage phenomenon Due to the influence of looseness and vibration of machine parts on the heating of the machine, the sealing surface and pipe joint of the machine will leak, and some defects such as casting and machining are difficult to find during assembly and debugging, but due to vibration and impact during operation, such defects are exposed, showing oil (water) leakage, so leakage is easy to occur during the running-in period. Operation errors are mostly due to ignorance of the structure and performance of the machine (especially for new operators), which is easy to cause failures and even mechanical accidents. Use and Maintenance As construction machinery is a special kind of vehicle, operators should receive training and guidance from the manufacturer, fully understand the structure and performance of the machine, and gain some operation and maintenance experience before operating the machine. The operation and maintenance manual provided by the manufacturer is the necessary information for the operator to operate the equipment. Before operating the machine, please read the operation and maintenance manual and operate and maintain it as required. Pay attention to the workload during the running-in period. Half of the working load during the running-in period should not exceed 60% of the rated working load, and appropriate working load should be arranged to prevent the machine from overheating due to long-term continuous operation. Pay attention to observe the instructions of various instruments frequently, stop and eliminate any abnormality in time, and stop the operation before the cause is found out and the fault is not eliminated. Pay attention to regularly check the level and quality of lubricating oil, hydraulic oil, coolant, brake fluid and fuel (water), and pay attention to check the tightness of the whole machine. During the inspection, it is found that there is too much oil and water shortage, so the reasons should be analyzed. At the same time, the lubrication of all lubricating points should be strengthened. It is recommended to add grease to each shift of lubricating points during running-in period (except for special requirements). Keep the machine clean, adjust and tighten loose parts in time to prevent parts from being worn or lost due to looseness. At the end of the running-in period, the machine shall be subject to compulsory maintenance, inspection and adjustment, and the oil shall be changed. In short, the requirements for the use and maintenance of loaders during the running-in period can be summarized as: strengthening training, reducing load, paying attention to inspection and strengthening lubrication. As long as the loader is maintained as required during the running-in period, the occurrence of early failures will be reduced, the service life will be prolonged and the work efficiency will be improved. The new machine didn't bring you more benefits. Operating rules 1) Before driving and operation, the operator should be familiar with the performance, structure, technical maintenance and operation methods of the loader and operate according to the rules. 2) No passengers are allowed except in the cab. 3) When discharging into the car, the bucket must be lifted to a height that will not touch the trunk baffle to prevent the bucket from touching the trunk, and it is forbidden to cross the bucket from the top of the cab. 4) Use automatic deceleration when going downhill, and don't step on the clutch pedal to prevent the car from slipping when power is cut off. 5) The loader should stop immediately after wading. If it is found that the brake fails due to flooding, it should be braked continuously, and the moisture in the brake pad should be removed by heating to make the brake return to normal as soon as possible. 6) When the loader is working, no one is allowed to stand in front, and the bucket is not allowed to be manned while driving. 7) When working, it is forbidden to stand under the shovel arm, and irrelevant personnel and other machinery are forbidden to work and pass here. 8) It is forbidden to use high-grade operation. 9) When the operator leaves the driving position, the bucket must be grounded, the engine must be turned off and the power supply must be cut off.