Backhoe loaders are commonly known as "busy at both ends". Because it has a unique structure, the front end is a loading device and the rear end is a digging device. In the construction site, you only need to rotate the seat once to complete the role change from loader to excavator operator. Backhoe loaders are mainly used in urban and rural road construction and maintenance, cable laying, electric power and airport engineering, municipal construction, farmland water conservancy construction, rural residential construction, mountain quarrying, and various building construction projects undertaken by various small construction teams . "Busy at both ends" is a kind of small multifunctional construction machinery, which is generally used in small projects after the completion of large projects.
First, classification of backhoe loaders
The backhoe loader is commonly known as "busy at both ends" and has both loading and backhoe functions. The backhoe loaders are classified as follows:
1.Structurally
In terms of structure, there are two types of backhoe loaders: one with side-shifting frame and the other without side-shifting frame. The biggest feature of the former is that the excavation work device can be moved sideways, which is convenient for working in special sites. It has a low center of gravity when it is transported, which is conducive to loading and transportation. Disadvantages: due to structural constraints, the outriggers are mostly straight legs, the support points are within the edge of the wheel, the distance between the two support points is small, and the stability of the whole machine is poor during excavation (especially when the excavation work device is moved to one side). The function of this type of backhoe loader focuses on loading, and it is produced more in Europe; the latter's excavation work device cannot be shifted sideways, and the entire excavation work device can be rotated 180 ° around the center of the rear of the frame through slewing bearings. The leg is a frog leg type support, and the support point can be extended behind the outside of the wheel. It has good stability during digging and is conducive to the improvement of digging ability. Because there is no side-shifting frame, the cost of the whole machine is correspondingly reduced. The disadvantage is that the bucket is suspended at the rear of the car when the bucket is retracted, and the appearance is long. When the locomotive is in the state of transportation and loading, the stability is poor, which has a certain impact on loading and transportation. The function of this model focuses on excavation and is produced in the United States. Mostly.
2.In power distribution
From the point of power distribution, the backhoe loader has two types of drive (rear-wheel) and four-wheel (all-wheel). The former cannot make full use of the attached weight, which reduces the adhesion and traction of the locomotive to the ground than the latter, but the cost is much lower than the latter.
3.On the chassis
Chassis comes up: Of the three chassis commonly used in small multi-functional construction machinery, the power of the mini excavator is mostly below 20kW, the mass of the machine is 1000-3000kg, the crawler walking mechanism is used, and the walking speed is less than 5km / h. It is mostly used in farms and gardens. Wait for small-scale earthmoving operations. Due to its small size and high cost, it is still difficult to popularize in China. The power of backhoe loaders is mostly 30-60kW, the weight is about 5000-8000kg, and the excavation capacity is strong. Type travelling mechanism, all-wheel drive, using steering drive axle or articulated steering, the vehicle speed is high, more than 20km / h, and it is widely used abroad for earthwork, earthwork, and auxiliary work on large construction sites, such as farms, infrastructure, road maintenance and so on. This model has a large shape and poor flexibility, and it is generally difficult to adapt to operations in small places.
Second, domestic status and development trend of backhoe loaders
1. Domestic technology status
At present, there are more than 10 manufacturers of backhoe loaders in China, mainly Shangong, Tobacco, Chaoyang, Liugong, Xiagong, Changlin, Beijian, Xugong, etc. At present, the annual output of this product is about 400 units. Judging from the history of the development of small-scale, multi-functional excavating and loading machines in China, China's backhoe loaders have been in a relatively backward state, and their development speed is slow. China began its own development and design in the early 1970s. First, the Beijing Construction Machinery Factory successfully developed the WZ2A and WZ2B hydraulic backhoe loaders. In 1987, the Yantai Construction Machinery Factory trial-produced the Z115WJ backhoe loader. Later, Fujian Construction Machinery Factory, Yishi, and Shandong Guangrao Hydraulic Machinery Factory successively developed WZ25, DFH-904WZ, and T55Z / w backhoe loaders. By 1992, Liuzhou Backhoe Loader Factory and Liuzhou Engineering Machinery Co., Ltd. had developed them Launched WZ30-25 and WZ25-20 backhoe loaders. Shandong Engineering Machinery Plant successfully developed WZ30-25 backhoe loader in July 2001.
The picture shows the busy equipment of Case 580L used by members of this website
The picture shows the busy equipment of Case 580L used by members of this website
The following 名媛直播 basically represent the current technical level of domestic backhoe loaders:
① WZ30-25 backhoe loader from Changlin: The engine system is Cummins turbocharged engine with a rated power of 63kN and its emissions meet European standards. The steering car (front axle) of the standard car is a non-driven swing axle, and the bearings are imported. The imported drive axle (rear axle) specially designed for backhoe loaders is selected. With maintenance-free wet brake, greatly improving the safety and reliability of driving. With differential lock, improves the traction performance of the whole vehicle. The standard car is two-wheel drive, and can be equipped with four-wheel drive according to user needs. The hydraulic system uses a high-efficiency gear single pump system, and the main components such as pumps, multi-way valves and steering gears are all selected from well-known foreign companies.
② WZ25-20 type produced by Yantai Engineering Machinery Factory: WZ25-20 type backhoe loader is mainly based on loader, with multi-purpose bucket modified at the front end and excavation device installed at the rear end. YTO's Dongfanghong 904WZ backhoe loader is based on the introduction of Italian Fiat technology to manufacture the 1F90 tractor. Supporting design of agricultural engineering machinery with multiple functions such as front loading and back digging. [!-empirenews.page--]
③WZ30-25 of Liuzhou Backhoe Loader Factory: WZ30-25 Backhoe Loader produced by Liuzhou Backhoe Loader Factory and WZ30-20 Backhoe Loader developed by Liuzhou Engineering Machinery Co., Ltd. are both digesting and absorbing CAT backhoe Based on machine technology, a new product developed in combination with China's technological characteristics. Both models use a dedicated chassis and use the same load sensing control technology as CAT. Because these two models use variable systems, the system's cleanliness and the reportability of components are high. ④Huzhou 995E series backhoe loader:
Engine: equipped with an advanced turbocharged diesel engine with a rated power of 95 horsepower and a torque of 384 Nm at a speed of 1500 rpm. The core key components are imported from world-renowned brand 名媛直播 and have higher reliability. The new appearance is beautiful and generous, and the cab has more space; the standard configuration of the 4-in-1 bucket makes the machine have more functions and uses. A variety of working accessories can be selected for more tasks; a special frame for backhoe loaders is used. The cab is independently replaceable and is connected to the frame by 5 shock absorbers. The hydraulic oil tank and fuel tank are also independently replaceable and arranged in a low position, which is conducive to reducing the center of gravity of the machine and improving stability, and is suitable for standing on the ground for fuel filling and maintenance. At the same time, they also become part of the boarding ladder, which is convenient for the operator to enter and exit.
⑤Taian Loader Factory WZ30-25: Power system: This machine uses Cummins 4BT3.9-C74 turbocharged engine, which has the characteristics of compact structure, high power, low fuel consumption, low noise, reliable work, long life and so on. Low temperature starting performance, especially suitable for northern regions.
Hydraulic system: This machine uses the original German Rexroth pump and control valve. The system adopts load sensing control technology. When the main valve spool is in the neutral position, the pressure difference signal generated by operating the valve is fed back to the variable pump, thereby automatically reducing the displacement of the pump and bringing the flow to approximately zero. At this time, the pump pressure Reach the set pressure of 22MPa to ensure the required pressure of the side-clamping cylinder. When working, the pump provides the required flow according to the opening size of the valve spool of the control valve, which avoids the traditional hydraulic system relying on the relief valve to control the overflow, which minimizes the air flow loss of the hydraulic power and the system heat.
Working device: The backhoe device has a side frame structure, which is fixed by 4 compacting cylinders and the rear frame. The backhoe device can be moved sideways along the slideway, expanding the operating range. The boom of the backhoe device adopts a large camber boom, which is helpful to reduce the lateral dimension when swinging and retracting. When walking, the backhoe device moves to the left and right ends along the slide side, the arm and bucket are retracted, and then swing back to the end of the rear frame. This greatly reduces the length and size of the entire machine during travel and transfer, improves maneuverability, enables the machine to be moved and operated in narrow places, and the distribution of the center of gravity of the whole machine is more reasonable, which is beneficial to the stability of the machine. The operation mechanism of the backhoe device is a mechanical 2-bar operation, which is flexible and convenient. The loading device adopts a Z-shaped reversing double rocker link mechanism, which has the characteristics of large unloading height, large unloading distance, large breakout force, and automatic equalization; the use of a stamped box type lifting arm reduces weight, improves rigidity and load ability. The control mechanism is a mechanical single handle.
Traveling system: The driveless front axle is adopted, and the steering cylinder is a double-piston double-acting cylinder; the rear axle is a drive axle, and a two-stage reduction transmission structure is adopted. The drive motor is installed on the main reducer housing, and it uses helical bevel gear transmission. The wheel reducer is a planetary gear transmission mechanism. The overall structure is good in rigidity and the output speed is stable. Between the main reducer and the wheel reducer, a full-floating half-shaft connection transmission is used to overcome the influence of the axle housing on the half-shaft transmission during the work deformation process. The walking system uses hydrostatic transmission. The frame adopts an overall welded structure, which has the characteristics of good rigidity and high strength. The outriggers are H-shaped straight legs connected to the frame. The drive axle is braked by hydraulic caliper and disc. Hydraulic operation has the advantages of fast and reliable braking. The parking brake is a drum-type central brake, which is mechanically operated. The backhoe end of the cab is an integrated large window inward structure, which is conducive to ventilation, wide field of vision, and convenient operation. The rear drive wheels use large-diameter low-pressure tires, which can cushion vibrations and reduce vehicle bumps during walking, improving the driver's riding comfort. Due to the late start of China's backhoe loaders, there is a considerable gap compared with foreign countries in terms of product variety, performance parameters, use reliability, and after-sales service.
2. Domestic Competitive Backhoe Loaders and Domestic Development Trends
At present, domestic backhoe loader competitors are divided into:
①Export type: For example, more than 80% of the multifunctional engineering machinery produced by Sichuan Highway Machinery Factory is exported, and the market has been very good. In addition, Guilin Forestry Machinery Factory specializes in the production of small crawler backhoe loaders, and most of the 名媛直播 are exported.
②Foreign parts, domestic assembly type: such as Shanghai's CASE 580/590 series 名媛直播. Foreign imports, domestic agency type: such as JCB's 2CX / 3CX / 4CX; VOLVO's B160 / B171; CASE's 580/590, etc. have agents at present.
(3) Domestic production enterprises: There are more than 10 domestic production enterprises whose 名媛直播 are low-grade backhoe loaders. The price is less than 380,000 yuan. Therefore, the domestic development trend of backhoe loaders is to introduce advanced foreign technology, develop high-quality, multifunctional, multi-variety, and multi-specification backhoe loader 名媛直播, strengthen the production of basic components and components, and especially improve backhoe loaders. The quality of hydraulic components can reduce the cost of backhoe loader 名媛直播 and increase the level of after-sales service of backhoe loader 名媛直播 on the premise of meeting product reliability.
3. Disparities at home and abroad and development requirements
Because of the late start of China's backhoe loaders, there is a considerable gap compared with foreign countries in terms of product varieties, performance parameters, use reliability, and after-sales service. appears in:
The main parts of domestic backhoe loaders are not as reliable as their counterparts abroad. Existing reliability problems are: diesel engines, hydraulic components, cleanliness of hydraulic systems, transmission components, electrical systems and electrical components, fastening technology and sealing technology, tires and operating devices. Backhoe loader 名媛直播 have poor performance and low reliability. In addition to some 名媛直播 imported from abroad in recent years, the performance of some domestic backhoe loaders is still at the level of the international 1990s, and the early failure rate is high, which cannot fully meet the requirements for road construction. The quality of the backhoe loader's basic parts is poor, and the quality of the supporting parts is not too hard. At present, the quality of cylinders, pumps and valves of domestic engines and hydraulic systems has become a "bottleneck" that restricts the quality of backhoe loaders. [!-empirenews.page--]
The backhoe loader has few varieties, poor completeness, and incomplete models, and some 名媛直播 do not form a series. China's backhoe loaders still have a lot of gaps in terms of varieties and models.
Existing backhoe loader 名媛直播 lack innovation and unique technology. The research and development of backhoe loaders in China lacks innovation and does not have its own unique technology. When attaching importance to technology introduction, less attention is paid to digestion, absorption, and mastery and research of key technologies. Therefore, the development of domestic backhoe loaders should develop high-quality, multi-functional, multi-variety, multi-specification series 名媛直播, and strengthen the production of basic components and parts, especially to improve the quality of hydraulic components in order to meet product reliability Under the premise, reduce product costs and improve product after-sales service levels.
Third, several problems in the development and development of backhoe loaders
According to relevant regulations, 名媛直播 manufactured outside China for special equipment sold in China must meet the requirements of laws, administrative regulations, rules, compulsory standards, and technical regulations on special equipment in China. Accept safety supervision and type test at the same time. Since backhoe loaders have not been really included in the management of special equipment, foreign backhoe loaders can be moved in and out freely, and there is no restriction or supervision in terms of technology and management. However, domestic backhoe loaders have to undergo type tests and accept some places. Supervision and inspection by the quality supervision department, the same product gets different treatment. As a production, development and manufacturing enterprise of special equipment such as backhoe loaders, it is imperative that they should make technical, product and production and management preparations in accordance with relevant requirements, and actively apply to obtain domestic production and manufacturing qualifications. And take this as a chance to increase product improvement, actively implement international standards and advanced foreign standards, and constantly improve product quality and technology to meet the needs of market internationalization.
2, Positioning of backhoe loader 名媛直播
① Positioning of backhoe loaders: For enterprises: At present, the market forecasting capacity of backhoe loaders should be strengthened, the ability to respond to the backhoe loader market should be strengthened, and the market information of backhoe loaders should be collected in time to grasp the market trends of backhoe loaders. Only in the development of new product development of backhoe loaders can enterprises take the lead in seizing the market in the fierce market competition, forever invincible, and embark on the road of sustainable development. The construction machinery manufacturers in the western developed countries have already stepped out of the blind stage. No matter what kind of product they develop, they will have a clear market positioning, produce different 名媛直播 for different consumer groups, and develop small construction machinery in developing countries such as China. , Product positioning must be accurate. Different technologies and different user groups should be used to solve the problem of accurate positioning. China should first develop small construction machinery 名媛直播 for the vast rural areas of the coastal developed areas and for the use of supporting construction projects. This is a diversified social structure with Chinese characteristics. Impact of changes in demand structure.
At present, enterprises should first find their own positions and determine which 名媛直播 to produce according to their own strengths; then they should take the pulse of the 名媛直播 and decide how to produce them. Enterprises must grasp the pulse of the quasi-market and adjust their development ideas in a timely manner. In addition, they should learn from foreign advanced experience and develop small-scale engineering machinery 名媛直播 with Chinese characteristics independently for the Chinese market. They can also conduct joint development with foreign companies. Small 名媛直播 need to highlight low cost, practicality, and a large and clear user base. While continuing to refine and do a good job of XCMG's existing leading 名媛直播, and in accordance with the requirements of market development, combined with the advantages of enterprises, develop more small construction machinery 名媛直播 that are marketable. According to the technical level of China's backhoe loaders and the current market conditions, the following aspects should be taken as the ideas for developing new 名媛直播 in the development of backhoe loaders.
1 (1) As soon as possible, digest or absorb advanced technology of backhoe loaders from abroad to improve the quality of our 名媛直播;
(2) A domestic quantitative system can be used to reduce the requirements for oil cleanliness and reduce the occurrence of failures;
3 (3) Key components of backhoe loaders, such as engines, torque converters, transmissions, rear axles, hydraulic pumps, multi-way valves, etc., should be sourced globally to improve product reliability;
4 (4) Use a dedicated integrated frame and frog leg support to improve the stability of product walking and work;
5 (5) Domestic use of a structure without steering front axle and without side shifter to improve the utilization rate of the mechanism and reduce the manufacturing cost;
(6) Supplemented with multi-functional operation tools to improve product utilization.
(7) The market price of domestic control is around RMB 450,000-600,000; the market price of foreign control is around RMB 7.5-900,000.
②Current domestic price positioning:
According to the survey, the current technical positioning of domestic production of backhoe loaders is: domestic mid-range and low-end positioning, both at 200,000 to 400,000 yuan. Lin, Beijian, and Changgong backhoe loaders all have similar prices. Domestic high-end positioning: The current domestic high-end positioning is Liuzhou Auliu Machinery Co., Ltd. HUAEACH995E, the price is 850,000 yuan.
3. It is recommended to develop other multifunctional construction machinery while developing backhoe loaders
Skid steer loader and backhoe loader with two busy ends are two typical examples of multi-purpose one. The former can complete dozens of operations such as digging, loading, bulldozing, leveling, and hoisting, and the latter has multiple functions such as digging, loading, lifting, and backfilling. They have the characteristics of both small machines and multi-functions, and are especially suitable for narrow field operations that need to complete a variety of operations but cannot accommodate multiple machines at the same time. In order to improve the utilization rate of equipment, multi-use of one machine has become a direction for the development of construction machinery. [!-empirenews.page--]
The first is to install some attachments on general equipment, which can be used for a variety of construction operations. Equipped with auxiliary tools on the hydraulic excavator, it can complete tasks such as trenching, bulldozing, stacking, loading, handling, backfilling, flat land, compaction and slope correction, and site cleaning. Caterpillar's series of bulldozers have adjustable tilt (P) blades, straight (S) blades, universal (V) blades, angled (A) blades, rippers and traction winches. For different operation methods. Volvo's loaders have 60 to 70 types of replaceable working devices, such as grapples, side dumpers, stone clamps, wood clamps, snowboards, dozers, lifting and forklifts, etc. Users include agriculture, water conservancy, forestry, transportation, construction and other departments.
When developing backhoe loaders, we should also consider the development of other multi-functional construction machinery, such as multi-functional bulldozers, multi-functional bulldozers, multi-functional tractors, multi-functional tractors, multi-functional tractors Stone shovel, multifunctional trail roller, multifunctional trencher, multifunctional pipelayer, multifunctional crane, multifunctional crusher, multifunctional crushing shear, multifunctional cold milling machine, multifunctional grab loader , Four-in-one multi-functional load bulldozer, multi-functional road breaker, milling or bucket chain trencher, multi-functional slope trimmer, multi-functional lawn mower, multi-functional aerial work vehicle, multi-functional drilling machine More than 60 independent models such as multi-functional forklifts and multi-functional compactors.
Separately developed and developed a multifunctional engineering machine with a car as the chassis, which can be replaced with about 100 kinds of working devices. In Western European countries, the Mercedes-Benz UNIMOG special chassis is mainly used. The main 名媛直播 converted are screw filling machines and sweepers, snowplows, bulldozers, loaders, cable laying machines, excavators, truck-mounted cranes in various structural forms. , Trencher, rock crusher, pile driver, grab excavator, tree planter, rotary drilling rig, aerial work trolley.
1. Management of special equipment belonging to backhoe loader
The state promulgated in 2003 in order to strengthen and standardize the management of special equipment that involves life safety and high risks, in order to meet the requirements of the internationalization of the market after China's entry into the WTO, and to rationally and legally use trade rules to protect the interests of the country and people. Implemented a series of regulations such as the "Special Equipment Safety Supervision Regulations" (Order No. 373 of the State Council), "Implementation Measures for Special Equipment Administrative Licensing (Trial)" (GuoQianGuo [2003] No. 172) and other series of regulations. At the same time, the General Administration of Quality Supervision, Inspection and Quarantine (hereinafter referred to as the General Administration of Quality Supervision, Inspection and Quarantine) formulated the "Mechanical and Electrical Engineering" based on the "Special Equipment Safety Supervision Regulations" and "Special Equipment Quality Supervision and Safety Supervision Regulations" (formerly the State Quality and Technical Supervision Bureau Order No. 13). "Special Equipment Manufacturing License Rules (Trial)" (National Quality Inspection Pan [2003] No. 174), which is used to regulate the manufacturing license of mechanical and electrical special equipment to ensure the manufacturing quality and safety technical performance of mechanical and electrical special equipment.
According to the implementation requirements of the document, some 名媛直播 that are included in the special equipment license list, such as loaders, backhoe loaders, excavators, and lifting machinery, are listed in the special equipment management before June 1, 2004. Otherwise, a corresponding manufacturing license must be obtained, otherwise Enterprises will not be allowed to produce or sell 名媛直播. At present, the most specific regulations on the types and product types of equipment contained in motor vehicles in the plant are the "Electrical Machinery Special Equipment Manufacturing License Rules (Trial)". The catalog of special equipment manufacturing licenses stipulated will currently belong to the equipment of motor vehicles in the plant. The types and corresponding equipment types are clearly defined (see the table below), which should be the basis for future management of motor vehicles in the plant.
