China Automotive Network Truck Crane Columns Listed by China Ministry of Industry and Information Technology Automobile Cranes Automobiles Announcement All 4 Categories 40 Manufacturers 35 Truck Crane Brands 1258 Truck Cranes Product Information, Latest Truck Crane Announcements, Environmental Notices, Fuel Bulletins, Free Announcements, pictures, news and information on the most timely prices of truck crane quotes.
Introduction
Development history China's automobile cranes were born in the 10th century of the last century. After nearly 30 years of development, there have been three major technological improvements during the period, including the introduction of Soviet technology in the 1970s and the introduction of Japanese technology in the 1980s. The introduction of German technology. But overall, China's auto-crane industry has always taken the path of independent innovation and has its own clear development lines. Especially in recent years, China's auto crane industry has made considerable progress, even though compared with foreign countries. There is a certain gap, but this gap is gradually narrowing. Moreover, the performance of China's current car-type cranes with medium and small tonnages is already intact and can meet the requirements of actual production. In the near future, China's auto crane industry will certainly develop into a mature industry with stable development and high degree of marketization. Many experts believe that the rapid development of the market is a favorable technological innovation basis and environment for various manufacturers of China's auto crane industry. In recent years, apart from a joint venture between a smaller company and a Japanese crane brand manufacturer, the rest of the Chinese auto crane industry has been following the advanced international standards and has always insisted on its own path of technological innovation. There has been no overall introduction of foreign technologies. This approach also makes the Chinese auto-crane industry reach and close to the international advanced level, and has obvious Chinese characteristics in product technology. China's auto cranes have made extensive use of PLC programmable integrated control technology. Hydraulic valve blocks, hydraulic motors, oil pumps and other control and actuator components with bus interfaces have become more mature. Hydraulic and electrical appliances have achieved close integration. Can realize the adjustment of control performance through the software, greatly simplify the control system, reduce hydraulic components, improve the stability of the system, have the ability that realizes automatic diagnosis of trouble, long-range control. At present, China's new generation of mobile crane products, the operation mode of lifting operations, the application of pilot proportional control over a large area, has good fine-tuning performance and fine control performance, small operating force, and is not easy to fatigue. Through the pilot proportional handle, the stepless speed regulation of multi-load conveying is realized, which effectively prevents the secondary slippage during the lifting operation, and greatly improves the safety, reliability and working efficiency of the lifting operation. Some large-scale automobile cranes also use the telescopic technology of single-cylinder plugs on the telescopic arm. Through the action of hydraulic pins, a single hydraulic cylinder can complete multi-section arm motion and achieve various degrees of control and automatic expansion. It has changed the previous way that no oil tanks and internal rope rows can be used, making the cranes relatively lighter and expanding the space for cranes to develop at higher working heights. In the process of moving to the international market, the rapid improvement of the quality of China's auto crane industry in recent years has also been highly recognized by the international (3) advocacy. Due to the standard of product use, the professional quality of users is higher and the quality feedback ratio of export products is higher. In the past, there has been a noticeable reduction in product response. This laid a good foundation for the development of China's auto crane industry. [1] Truck Crane Features 1. Luxurious full cab and cab with modern streamlined style; 2. Large power, low fuel consumption, noise in line with national standards; 3. Take the platform for full coverage, easy to work and repair in the car; 4. Outrigger system adopts double-sided operation, convenient and practical; 6. Each performance index of the product basically reaches the performance index of more than 50 tons of products in many fields; the working principle is that there is a rotating reel under the inside of the lifting arm and the wire rope is wound on it. The wire rope passes through the pulley on the top of the next arm and it will A boom lifts out, and so on. When retracted, the drum is retracted to retrieve the wire rope and the boom is retracted under its own weight. This rotating drum is driven by a hydraulic motor so you can see the two tubings, but do not use them as cylinders. In addition, there are some truck cranes equipped with piston-type cylinders inside the telescopic arms, but this type of application is rare. Because the multi-stage piston type cylinder is expensive, and the boom will flex when loaded, it will greatly affect the life of the cylinder.
Automobile Crane Design Outsourcing Definition Automobile Crane Design Outsourcing Service: Refers to the enterprise customer hires a professional car crane design service provider, provides enterprise customers with a full range of CMD technical services, to enhance the company's technological superiority and reduce development cost behavior. Classification Development Design: Apply mature design experience or have feasible new technologies to design a new type of truck crane, mainly including functional design and mechanism design. Upgraded design: According to the use of experience and technological development, the existing truck crane design is upgraded and upgraded to improve performance, reduce manufacturing costs or reduce operating costs. Derivative design: In order to adapt to new requirements, some existing cranes are modified or added or deleted to develop derivative products that are different from the standard ones. Serialized design: Using a truck crane as a parent, a series of products with the same shape and function but different power, tonnage, and size are designed. Development Process 1. Develop requirements analysis. According to factors such as function, performance and operating environment, together with the customer to develop a detailed user requirements specification, and then determine the development goals. Second, the initial design. According to the demand analysis, the formulation of the plan, including the setting of functions and parameters, basic calculations, drawing of the preliminary three-dimensional total, etc., will be carried out with the customer for preliminary examination. Third, detailed program design. Hear the opinions of the first instance and implement the plan design. Modify the generalized three-dimensional model, draw three-dimensional parts, and perform finite element analysis and dynamic simulation on the structural components. Then perform a second review with the customer. Fourth, final program determination and drawing. Listen to the opinions of the second instance and modify the design of the plan. Drawing plans (such as parts drawings, assembly drawings and general assembly drawings, painting drawings, etc.), list of parts, list of wearing parts. 5. Make all technical documents, including publicity and technical samples, and product manuals.
Types and Structures Types of Truck Cranes There are many types of truck cranes, and their classification methods are also different. They mainly include: Classified by weight: light truck cranes (up to 5 tons lifting capacity), medium-sized truck cranes (lifting weight 5-15 tons), heavy-duty truck cranes (lifting weight 5-50 tons), heavy-duty truck cranes (lifting weight More than 50 tons). In recent years, due to usage requirements, there has been a trend of increase in weight, such as the production of 50 to 100 tons of large truck cranes. According to the type of legs: frog legs, x-type legs, h-type legs. The span of the frog legs is smaller than the 0? It is only suitable for cranes with smaller tonnage; the x-type legs are easy to generate slip and rarely used; the h-type legs can realize larger spans, and the stability of the whole machine is obvious. Because of its superiority, China's current production of hydraulic truck cranes often use h-type legs. According to the transmission of the transmission points: mechanical transmission, electric transmission, hydraulic transmission three categories. According to the lifting device in the level of the scope of rotation (that is, the scope of rotation of the turntable) points: full-rotary crane (rotary table can be rotated 360 °) and non-full-rotation crane (rotary table rotation angle is less than 270 °). According to the structure of the boom: folding boom, telescopic boom and truss crane crane truck. Basic Structure of Truck Cranes Truck cranes mainly consist of lifting, luffing, slewing, lifting booms and car chassis. Due to the development of hydraulic technology, electronics industry, high-strength steel and automotive industry, the development of truck cranes has been promoted. The mechanical transmission-type truck cranes that are heavy and have long working hours have been replaced by hydraulic truck cranes. The hydraulic system of the hydraulic truck crane adopts the hydraulic pump, the quantitative or variable motor to realize the hoisting rotation, the amplitude variation, the boom extension and the extension and extension of the crane and can be operated independently or in combination. The motor is protected from overheating and has safety devices that prevent erroneous operation. Large-tonnage hydraulic truck cranes use multiple gear pumps, which can also accelerate the above-mentioned actions. In the hydraulic system, there are automatic overload safety valves, buffer valves and hydraulic locks to prevent accidents caused by overloading or stalling of cranes and sudden rupture of oil pipes. The truck crane is equipped with an amplitude indicator and a height limiter to prevent overloading or over-extension. The reel and the pulley are provided with a device for preventing rope skipping. Lifting displays are required for cranes below 16t, torque limiters for cranes over 16t and 16t, and alarm devices. The boom of a hydraulic truck crane consists of multi-arm sections that can be designed according to the different requirements for lift height. One type of telescopic boom is sequential telescoping, and the other is synchronous telescoping. Large-tonnage cranes mostly use synchronous expansion to increase lifting capacity. The extension and contraction of each arm section is controlled by the hydraulic pressure and it can flex freely. In cranes with jibs, the jibs are generally placed laterally or below the main boom when the vehicle is in a running state. The turret is mainly used for arranging a lifting mechanism, a slewing mechanism, a boom and a lower fulcrum and an operating device of a luffing cylinder. For medium and large tonnage cranes, some of them also place engines on the turntable. Between the turntable and the base frame is a slewing bearing that can withstand vertical load, horizontal load and overturning moment. In order to prevent slipping of the turntable during driving, a turntable locking device is provided. The rotary mechanism is driven by a metered motor. The output gear of the slewing gear meshes with the slewing gear. The crane turret rotates 360° around the center of rotation. The luffing boom can be controlled by single or double hydraulic cylinders through oil control. The crane is configured to drive the reel through a speed reducer with an oil control variable or a dosing motor. Due to the use of hydraulic torque converters, the movement of the various mechanisms of the crane can be infinitely variable, allowing the load to be decelerated by the power control at the inching speed. In order to prevent overwinding, a three-ring wire rope protection device and alarm device are provided. The medium and large tonnage truck cranes can be equipped with auxiliary lifting mechanisms according to market demand for double hook operation.
Fitting construction and operation method A crane is a crane that mounts a part of a lifting operation on a general purpose or special purpose vehicle chassis and has the driving performance of a truck. In order to meet the driving requirements under harsh conditions, a mobile crane with off-road performance was derived. The truck crane has the following advantages: (1) Freedom of movement, with its lifting capacity and dimensions allowable, it can assume most of the lifting work in the entire factory or in the freight yard. (2) In addition to its use as a crane, it can be equipped with various shovel grabs, trenchers and shovels for other work on the boom. (3) Fixed structures such as overhead rails are not required, so infrastructure investment, production costs, or maintenance costs can be reduced. (4) It has its own independent power unit and does not need to be equipped with feeder cables or contact conductive devices. (5) It can place the load on the ground, under the ground or higher than the crane of a car. Due to these advantages, truck cranes are widely used in transportation, construction, mining, and road construction projects to load and unload large-scale parts, packages, bulk goods, and building components. In particular, truck cranes are widely used when the goods are scattered, the amount of goods to be sent or received is small, or the amount of installation work is small, and special lifting equipment should not be used. Larger lifting and transportation tasks can be accomplished on very small floors and spaces. It has the advantages of maneuverability, flexibility, long range, high lifting weight, and high speed. The truck cranes have implemented the export product quality licensing system, and products that have not obtained and quality licenses are not allowed to export.
Safety lock and speed limit analysis 1, after the brake lock The clearance between the valve core and the valve body of the truck crane directional valve is often sealed with a gap. Under the double action of its own gravity and lifting load, the high pressure fluid often passes through the directional valve spool and the valve body. The small gap is leaking slowly and cannot be effectively locked on the hydraulic cylinders or hydraulic motors of the respective institutions. Therefore, the fall of the hoisting weight, the shrinkage of the boom, the increase in the amplitude, and the sinking of the legs can easily occur. The normal work will result in the occurrence of serious accidents such as vehicle overturning and casualties. There are at least the following four security measures to eliminate hidden dangers. (1) In-line hydraulic lock in the return road The reverse oil circuit of the pilot-operated check valve may only be connected after its control oil input a certain pressure oil. It is a switching element that enables on-off control of the oil circuit. It is also commonly referred to as a hydraulic lock. The hydraulic lock is connected in series in the return line of the hydraulic cylinder (hydraulic motor), and its control oil line is connected with the oil inlet of the hydraulic cylinder (hydraulic motor), so that the return oil line can be in the braking state. Due to the non-pressure oil action of the control oil circuit, the hydraulic cylinder (hydraulic motor) is locked. The locking effect of the hydraulic lock depends on the shape of the valve plug and the structure of the valve. If the valve plug adopts the ball valve type or the slide valve type, the leakage will still be unavoidable, that is, the oil may leak through the gap generated by the valve core or the gap between the valve core and the valve body. Therefore, the hydraulic lock valve core used in the truck crane should use the core with good sealing performance, even if it is used for a long time, it can guarantee the oil leakage. According to the working condition of the truck crane, the IY-F high pressure hydraulic lock with unloading spool should be selected. For the leg oil circuit, there are two locking requirements for support locking and suspension locking. According to different oil passages, each leg can use a one-way hydraulic control check valve, a one-way hydraulic lock that can only act as a one-way lock, or a bi-directional hydraulic pressure that is formed by two hydraulically-controlled check valves that are cross-connected. lock. The latter scheme is generally used. Each leg lock must be set independently. (2) Series balance valve in the return line The balance valve is essentially a combination valve consisting of a one-way valve and an externally controlled internal-discharge type sequence valve. Its installation position and locking principle in an automobile crane are the same as that of a hydraulic lock, ie, it is installed in a return oil circuit. Shut off the oil circuit after braking. If there are no other special requirements for the oil circuit, hydraulic locks with relatively low prices should be used as far as possible. (3) Improve the tightness of hydraulic components The installation of hydraulic locks or counterbalance valves in the oil circuit does not necessarily ensure that the mechanism can be locked after braking, and the tightness of the hydraulic cylinder (hydraulic motor) is also a key factor that restricts the locking effect. There are two types of leaks in the hydraulic components: internal leakage and external leakage. Leakage in the hydraulic cylinder is not easy to detect, and it will cause the legs to retract, the arm to expand and contract, and the amplitude 3 mechanism can not lock and sink. Therefore, to improve the sealing effect of the hydraulic cylinder, the key is to solve the internal leakage problem that occurs inside. In general, the amount of oil leakage inside the hydraulic cylinder of a truck crane should be strictly limited. During the safety inspection, the piston's moving distance under the specified rated pressure shall not exceed 0.5 min within 10 min. Exceeding this value indicates that the sealing performance is not good. Replace the new Y-ring in time. (4) Lifting hydraulic motor external brake It is difficult for the hydraulic cylinder and the hydraulic motor to cause internal leakage for a long period of time. The leakage of the seal after the seal is worn is unknowingly produced. In this way, if the lock is tight, only one method of installing the brake can be used, and it can only be applied to a hydraulic motor that lifts and lowers the hoist. Others, such as boom extension and contraction, and amplitude change, cannot be used. The brake acting on the lifting mechanism is actually a small single-acting single-acting hydraulic cylinder. The brake is normally closed and the braking force depends on the spring force in the cylinder. In order to obtain the desired locking effect, it is of course desirable that the greater the spring force, the better. However, if the excessive spring force increases the energy consumption of the brake release, the external brake is an auxiliary measure of the locking scheme. 2, speed limit in sports Due to the long crane lift, boom telescoping, and jib boom lengthening, the acceleration due to gravity in the mechanism or load down process is also a prominent issue. The speed limit of truck cranes usually adopts the following two methods. (1) Series balance valve in return oil circuit The balance valve not only locks but also limits the speed. When the mechanism or load falls, the sequence valve in the balance valve can balance the action of the valve core to maintain the return flow of the hydraulic cylinder (hydraulic motor) in a stable state, so that the hydraulic cylinder (hydraulic motor) maintains an even speed motion. In order to obtain a uniform rate of descent, two points must be taken into account when designing the system: First, instead of balancing the valve, it is not possible to use a common one-way valve in combination with an externally controlled internal leakage sequence valve in order to save costs. This is because the balance valve is a combination of a one-way valve and an externally controlled internal leakage sequence valve, but its sequential valve has increased the double-layer spring, damper orifice, etc. to damp the valve core; the second is the control of the balance valve. The throttle valve must be connected in series in the oil circuit to make the spool of the sequence valve act “hysteresis†without changing its speed due to minor changes in the external pressure. In rate-limiting schemes, the use of balancing valves is the best and is the preferred method. (2) Speed ​​limit with manual reversing valve Among all the reversing valves, only the manual reversing valve can commutate at the same time, and the size of the opening of the control valve can be combined with the effect of the limited speed and throttling. Therefore, when the downward acceleration phenomenon occurs in the crane mechanism or the load of the truck, it can be solved by reducing the opening degree of the valve opening by the driver by reducing the pulling degree of the manual reversing valve handle. Of course, due to the shaking of the driver's hand, the speed limiting effect of the manual directional valve is not ideal, but because the loading and unloading speed of the truck crane is often constantly adjusted according to the specific conditions of the construction site, the movement of the mechanism is often not continuous. Intermittent operation, so a skilled driver can still receive a certain speed limit effect when manipulating manual reversing valve. In short, for the crane crane lifting, boom telescopic, boom boom amplitude 3 mechanism both lock and speed requirements, should use a balanced valve that can meet both the locking and speed limit requirements, and then mechanical braking .
Inspection items and performance indicators (1) The minimum dimensions of the strength, stiffness, stability, and structural parts of a crane in a corrosive working environment, and the anti-overturning stability shall comply with gb3811-83 "Crane Design Code". (2) The basic parameters of the truck crane shall comply with the provisions of jb/t1375-92 "Basic parameters of truck cranes and wheel cranes". (3) The safety performance of a truck crane shall comply with the provisions of gb6067-85 "Safety Regulations for Hoisting Machinery". (4) The design of the structure, mechanism, and electrical of the crane is carried out in accordance with gb3811-83 "Crane Design Code". (5) The stability of the crane crane shall comply with the provisions of gb6068.3-85 "Determining the Stability of the Test Regulations for Truck Cranes and Tire Cranes". (6) The rated lifting capacity table, the requirements and representation method of lifting height curve and performance parameter label shall comply with the provisions of jb4031-85 "Truck and Tire Crane Label". (7) The installation and commissioning of the crane safety device shall be carried out in accordance with the provisions of zbj80002-86 Safety Regulations for Truck Cranes and Tire Cranes. (8) The performance indicators of truck cranes shall comply with the requirements of zbj80003-87 "Technical Requirements for Truck Cranes and Tire Cranes". (9) Inspection methods for truck cranes: Press jb/sq1-87 "Product Quality Classification of Truck Cranes and Tire Cranes", jb4030.3-85 "Test Specification for Truck Cranes and Wheel Cranes", gb6068.1-85 "Cranes and Tire crane test specification general requirements, gb6068.2-85 "car crane and tire crane test specification test" and other standards. Product type test according to jb4030.1-85 "Operational Reliability Test for Truck Cranes and Tire Cranes", jb4030.2-85 "Testing Reliability of Truck Cranes and Tire Cranes", gb6068.4-85 "Motor Cranes" Tire crane test specification structure test "and other standards.
Safe operation of the crane is prohibited in front of the operation, that is, the center of gravity of the hook must not exceed the connection between the center of rotation and the center line of the front leg (left and right) when lifting. In the event that the lifting weight indicator device is faulty and cannot be used, the lifting capacity shall be determined according to the provisions of the lifting performance table, and the operation behavior of the crane must be regulated to ensure safety. When lifting heavy objects, it is not allowed to drop the arm; when the arm must be thrown down, the heavy objects should be put down to raise the operation again; when the arm falls, the throttle should be small, and when the arm is lifted, the throttle should be large; the rotation motion should be steady, and no sudden stop is allowed; before the operation It is necessary to carefully inspect and prohibit the use of unqualified steel wire ropes and lifting chains; when lifting heavy objects, it is not allowed to drop the arm; when the arm must be dropped, the heavy objects should be put down and raised again; the throttle should be small when the arm falls.
Packing, storage, transportation and ordering items The truck cranes are generally packed in bare containers, but they are painted with anti-rust oil to prevent rusting during storage and transportation. The relevant boring heads and markings are all hung on or printed on the surface of the truck cranes. Iron plate. When exporting truck cranes sign a specific export contract, the contents shall include: product type, quantity, technical specifications, special use requirements, packaging and transportation conditions, delivery date, payment methods, quality assurance, claims and arbitration and other terms.
Development Trends of Truck Cranes Domestic Development Trends The production enterprises of China's auto cranes need to do many things in order to survive and develop in this field. Due to the increase in market demand, they also require continuous innovation by manufacturers to ensure the performance of cranes. On the basis of it, we must continue to develop new products with larger tonnages to meet the needs of the market. Only in this way can we obtain nutrients and vitality from the market so that we can survive, develop in survival, and grow in development. The main trends should be the following: Expand product variety Within the enterprise, a comprehensive product research and development system should be established to enable serialization of products and complete varieties. A complete series of large, medium and small scales should be formed, and the number of products should be increased so that the scale of production can be continuously expanded. Increase lifting torque At present, most of the auto cranes produced in China are small and medium tonnage cranes with a capacity of 50 tons or less. With the development of society, the demand for large and flexible mobile cranes is increasing. This is the nutrient for the development of automobile cranes. So increasing the moment is imminent. Increase crane function With the rapid development of the national economy, users have more and more requirements for the use of truck cranes. They hope to be able to use more than one vehicle. They are not only used when carrying heavy objects, but also meet the needs of different environments and types of work. These are all future developments Find the direction. Make your own brand At present, China's auto crane production companies lack their own professional researchers and development teams, but instead imitate others' lives. The finished product has no development direction and competitiveness. The globalization of the economy in the future and a series of problems caused by this will transfer the competitive means from the traditional product and price levels to the brand competition. Therefore, major auto-manufacturing companies should strive to build their own brands so that they can grow and develop. Create self-occupied space to occupy the market China's major automobile crane manufacturing enterprises must continue to innovate, boldly carry out reforms that run urgently and intelligently, face the market, and structure Optimization, personnel restructuring, introduction of equipment, hard technical research and development, and occupying the market under the premise of continuous self-improvement. Foreign Development Trends Design, Manufacturing Computerization, Automation In recent years, with the widespread use of electronic computers, many foreign crane manufacturers have increased from the application of a crane aided design system (CAD) to the application of a computer for the design of crane modules. The modular design of the crane module is not only a reform of the design method, but also will affect the technology, production and management level of the entire crane industry. The replacement of old products will speed up the development of new products. For the improvement of the crane, only a few modules need to be changed; the design of a new crane requires only new and different modules to be combined, which improves the degree of generalization and enables the single-piece and small-volume products to be converted into relatively bulk module productions. Less modular forms, combined into different specifications of the crane, to meet market demand and enhance competitiveness. Innovation and Application of Crane Control Elements The positioning accuracy of the crane is an important requirement for the crane. Most of the cranes are equipped with corner encoders, gear chains, laser heads and steel plate holes. The positioning accuracy is usually ±3mm. Accuracy above 1mm requires additional positioning systems. Improvements in hoisting speeds and brakes for cranes are based on the use of low-speed crane hooks for precise positioning and the crane's braking system is also micro-processed for control and monitoring. The remote control system is used for automobile cranes and other mobile cranes. The system includes a controller on the controller and a receiver mounted on the crane. The controller has an electromagnetic radiation generator, a receiver and a crane. The transmission of the operating mechanism of the transmission is connected. The use of a remote controller not only saves manpower, increases work efficiency, but also improves the operator's working conditions. The distance detection anti-collision device of the crane adopts a radio signal anti-collision device. The anti-collision system is composed of a three-phase system and is used to monitor the distance of the front end of the crane. Generally, a warning signal is issued first, and then the vehicle speed is reduced to 50%. Finally, the motor power is cut off and the cart is braked.
The application of new materials and new processes Due to the application of new technologies in steel industry, the quality of steel products can be improved. When designing the strength of crane girders, higher allowable stresses can be used instead of higher safety factors in order to reduce the crane material. The amount of use reduces the weight and price of the equipment. The manufacture of components such as Wanda slewing bearings for cranes also benefits from the continuous production of new materials, making the cranes more light and better. In terms of machining, a large number of precision castings with less cutting are used, in particular aluminum alloy castings, processing equipment used in a large number of high-precision, high-efficiency machining centers, numerical control automatic machine tools, etc., and the quality is ensured, and labor productivity is reduced, and the productivity is lowered. The cost, at the same time, uses machinery instead of manual operations such as welding manipulators and manipulators in mechanical lines. The future development of foreign cranes is toward professionalization, standardization, and serialization. Only in this way can the fastest variety of products be manufactured and assembled. [2]
Introduction
The truck crane is a kind of crane mounted on the chassis of a common car or on the chassis of a special automobile. The driving cab is set separately from the crane control room. The advantage of this kind of crane is good mobility and rapid transfer. The disadvantage is that it is necessary to support the legs during work, and it is not suitable for driving, nor is it suitable for working on soft or muddy grounds. The performance of the chassis of the truck crane is the same as that of the truck with the same total weight of the entire vehicle. It meets the technical requirements of road vehicles and can therefore be used on all types of highways. Such cranes are generally equipped with two control rooms for getting in and out of the car, and the outriggers must be kept stable during operation. The range of lifting weight is large, ranging from 8 tons to 1000 tons. The number of axles on the chassis can range from 2 to 10. It is the largest output and most widely used type of crane.
Development history China's automobile cranes were born in the 10th century of the last century. After nearly 30 years of development, there have been three major technological improvements during the period, including the introduction of Soviet technology in the 1970s and the introduction of Japanese technology in the 1980s. The introduction of German technology. But overall, China's auto-crane industry has always taken the path of independent innovation and has its own clear development lines. Especially in recent years, China's auto crane industry has made considerable progress, even though compared with foreign countries. There is a certain gap, but this gap is gradually narrowing. Moreover, the performance of China's current car-type cranes with medium and small tonnages is already intact and can meet the requirements of actual production. In the near future, China's auto crane industry will certainly develop into a mature industry with stable development and high degree of marketization. Many experts believe that the rapid development of the market is a favorable technological innovation basis and environment for various manufacturers of China's auto crane industry. In recent years, apart from a joint venture between a smaller company and a Japanese crane brand manufacturer, the rest of the Chinese auto crane industry has been following the advanced international standards and has always insisted on its own path of technological innovation. There has been no overall introduction of foreign technologies. This approach also makes the Chinese auto-crane industry reach and close to the international advanced level, and has obvious Chinese characteristics in product technology. China's auto cranes have made extensive use of PLC programmable integrated control technology. Hydraulic valve blocks, hydraulic motors, oil pumps and other control and actuator components with bus interfaces have become more mature. Hydraulic and electrical appliances have achieved close integration. Can realize the adjustment of control performance through the software, greatly simplify the control system, reduce hydraulic components, improve the stability of the system, have the ability that realizes automatic diagnosis of trouble, long-range control. At present, China's new generation of mobile crane products, the operation mode of lifting operations, the application of pilot proportional control over a large area, has good fine-tuning performance and fine control performance, small operating force, and is not easy to fatigue. Through the pilot proportional handle, the stepless speed regulation of multi-load conveying is realized, which effectively prevents the secondary slippage during the lifting operation, and greatly improves the safety, reliability and working efficiency of the lifting operation. Some large-scale automobile cranes also use the telescopic technology of single-cylinder plugs on the telescopic arm. Through the action of hydraulic pins, a single hydraulic cylinder can complete multi-section arm motion and achieve various degrees of control and automatic expansion. It has changed the previous way that no oil tanks and internal rope rows can be used, making the cranes relatively lighter and expanding the space for cranes to develop at higher working heights. In the process of moving to the international market, the rapid improvement of the quality of China's auto crane industry in recent years has also been highly recognized by the international (3) advocacy. Due to the standard of product use, the professional quality of users is higher and the quality feedback ratio of export products is higher. In the past, there has been a noticeable reduction in product response. This laid a good foundation for the development of China's auto crane industry. [1] Truck Crane Features 1. Luxurious full cab and cab with modern streamlined style; 2. Large power, low fuel consumption, noise in line with national standards; 3. Take the platform for full coverage, easy to work and repair in the car; 4. Outrigger system adopts double-sided operation, convenient and practical; 6. Each performance index of the product basically reaches the performance index of more than 50 tons of products in many fields; the working principle is that there is a rotating reel under the inside of the lifting arm and the wire rope is wound on it. The wire rope passes through the pulley on the top of the next arm and it will A boom lifts out, and so on. When retracted, the drum is retracted to retrieve the wire rope and the boom is retracted under its own weight. This rotating drum is driven by a hydraulic motor so you can see the two tubings, but do not use them as cylinders. In addition, there are some truck cranes equipped with piston-type cylinders inside the telescopic arms, but this type of application is rare. Because the multi-stage piston type cylinder is expensive, and the boom will flex when loaded, it will greatly affect the life of the cylinder.
Automobile Crane Design Outsourcing Definition Automobile Crane Design Outsourcing Service: Refers to the enterprise customer hires a professional car crane design service provider, provides enterprise customers with a full range of CMD technical services, to enhance the company's technological superiority and reduce development cost behavior. Classification Development Design: Apply mature design experience or have feasible new technologies to design a new type of truck crane, mainly including functional design and mechanism design. Upgraded design: According to the use of experience and technological development, the existing truck crane design is upgraded and upgraded to improve performance, reduce manufacturing costs or reduce operating costs. Derivative design: In order to adapt to new requirements, some existing cranes are modified or added or deleted to develop derivative products that are different from the standard ones. Serialized design: Using a truck crane as a parent, a series of products with the same shape and function but different power, tonnage, and size are designed. Development Process 1. Develop requirements analysis. According to factors such as function, performance and operating environment, together with the customer to develop a detailed user requirements specification, and then determine the development goals. Second, the initial design. According to the demand analysis, the formulation of the plan, including the setting of functions and parameters, basic calculations, drawing of the preliminary three-dimensional total, etc., will be carried out with the customer for preliminary examination. Third, detailed program design. Hear the opinions of the first instance and implement the plan design. Modify the generalized three-dimensional model, draw three-dimensional parts, and perform finite element analysis and dynamic simulation on the structural components. Then perform a second review with the customer. Fourth, final program determination and drawing. Listen to the opinions of the second instance and modify the design of the plan. Drawing plans (such as parts drawings, assembly drawings and general assembly drawings, painting drawings, etc.), list of parts, list of wearing parts. 5. Make all technical documents, including publicity and technical samples, and product manuals.
Types and Structures Types of Truck Cranes There are many types of truck cranes, and their classification methods are also different. They mainly include: Classified by weight: light truck cranes (up to 5 tons lifting capacity), medium-sized truck cranes (lifting weight 5-15 tons), heavy-duty truck cranes (lifting weight 5-50 tons), heavy-duty truck cranes (lifting weight More than 50 tons). In recent years, due to usage requirements, there has been a trend of increase in weight, such as the production of 50 to 100 tons of large truck cranes. According to the type of legs: frog legs, x-type legs, h-type legs. The span of the frog legs is smaller than the 0? It is only suitable for cranes with smaller tonnage; the x-type legs are easy to generate slip and rarely used; the h-type legs can realize larger spans, and the stability of the whole machine is obvious. Because of its superiority, China's current production of hydraulic truck cranes often use h-type legs. According to the transmission of the transmission points: mechanical transmission, electric transmission, hydraulic transmission three categories. According to the lifting device in the level of the scope of rotation (that is, the scope of rotation of the turntable) points: full-rotary crane (rotary table can be rotated 360 °) and non-full-rotation crane (rotary table rotation angle is less than 270 °). According to the structure of the boom: folding boom, telescopic boom and truss crane crane truck. Basic Structure of Truck Cranes Truck cranes mainly consist of lifting, luffing, slewing, lifting booms and car chassis. Due to the development of hydraulic technology, electronics industry, high-strength steel and automotive industry, the development of truck cranes has been promoted. The mechanical transmission-type truck cranes that are heavy and have long working hours have been replaced by hydraulic truck cranes. The hydraulic system of the hydraulic truck crane adopts the hydraulic pump, the quantitative or variable motor to realize the hoisting rotation, the amplitude variation, the boom extension and the extension and extension of the crane and can be operated independently or in combination. The motor is protected from overheating and has safety devices that prevent erroneous operation. Large-tonnage hydraulic truck cranes use multiple gear pumps, which can also accelerate the above-mentioned actions. In the hydraulic system, there are automatic overload safety valves, buffer valves and hydraulic locks to prevent accidents caused by overloading or stalling of cranes and sudden rupture of oil pipes. The truck crane is equipped with an amplitude indicator and a height limiter to prevent overloading or over-extension. The reel and the pulley are provided with a device for preventing rope skipping. Lifting displays are required for cranes below 16t, torque limiters for cranes over 16t and 16t, and alarm devices. The boom of a hydraulic truck crane consists of multi-arm sections that can be designed according to the different requirements for lift height. One type of telescopic boom is sequential telescoping, and the other is synchronous telescoping. Large-tonnage cranes mostly use synchronous expansion to increase lifting capacity. The extension and contraction of each arm section is controlled by the hydraulic pressure and it can flex freely. In cranes with jibs, the jibs are generally placed laterally or below the main boom when the vehicle is in a running state. The turret is mainly used for arranging a lifting mechanism, a slewing mechanism, a boom and a lower fulcrum and an operating device of a luffing cylinder. For medium and large tonnage cranes, some of them also place engines on the turntable. Between the turntable and the base frame is a slewing bearing that can withstand vertical load, horizontal load and overturning moment. In order to prevent slipping of the turntable during driving, a turntable locking device is provided. The rotary mechanism is driven by a metered motor. The output gear of the slewing gear meshes with the slewing gear. The crane turret rotates 360° around the center of rotation. The luffing boom can be controlled by single or double hydraulic cylinders through oil control. The crane is configured to drive the reel through a speed reducer with an oil control variable or a dosing motor. Due to the use of hydraulic torque converters, the movement of the various mechanisms of the crane can be infinitely variable, allowing the load to be decelerated by the power control at the inching speed. In order to prevent overwinding, a three-ring wire rope protection device and alarm device are provided. The medium and large tonnage truck cranes can be equipped with auxiliary lifting mechanisms according to market demand for double hook operation.
Fitting construction and operation method A crane is a crane that mounts a part of a lifting operation on a general purpose or special purpose vehicle chassis and has the driving performance of a truck. In order to meet the driving requirements under harsh conditions, a mobile crane with off-road performance was derived. The truck crane has the following advantages: (1) Freedom of movement, with its lifting capacity and dimensions allowable, it can assume most of the lifting work in the entire factory or in the freight yard. (2) In addition to its use as a crane, it can be equipped with various shovel grabs, trenchers and shovels for other work on the boom. (3) Fixed structures such as overhead rails are not required, so infrastructure investment, production costs, or maintenance costs can be reduced. (4) It has its own independent power unit and does not need to be equipped with feeder cables or contact conductive devices. (5) It can place the load on the ground, under the ground or higher than the crane of a car. Due to these advantages, truck cranes are widely used in transportation, construction, mining, and road construction projects to load and unload large-scale parts, packages, bulk goods, and building components. In particular, truck cranes are widely used when the goods are scattered, the amount of goods to be sent or received is small, or the amount of installation work is small, and special lifting equipment should not be used. Larger lifting and transportation tasks can be accomplished on very small floors and spaces. It has the advantages of maneuverability, flexibility, long range, high lifting weight, and high speed. The truck cranes have implemented the export product quality licensing system, and products that have not obtained and quality licenses are not allowed to export.
Safety lock and speed limit analysis 1, after the brake lock The clearance between the valve core and the valve body of the truck crane directional valve is often sealed with a gap. Under the double action of its own gravity and lifting load, the high pressure fluid often passes through the directional valve spool and the valve body. The small gap is leaking slowly and cannot be effectively locked on the hydraulic cylinders or hydraulic motors of the respective institutions. Therefore, the fall of the hoisting weight, the shrinkage of the boom, the increase in the amplitude, and the sinking of the legs can easily occur. The normal work will result in the occurrence of serious accidents such as vehicle overturning and casualties. There are at least the following four security measures to eliminate hidden dangers. (1) In-line hydraulic lock in the return road The reverse oil circuit of the pilot-operated check valve may only be connected after its control oil input a certain pressure oil. It is a switching element that enables on-off control of the oil circuit. It is also commonly referred to as a hydraulic lock. The hydraulic lock is connected in series in the return line of the hydraulic cylinder (hydraulic motor), and its control oil line is connected with the oil inlet of the hydraulic cylinder (hydraulic motor), so that the return oil line can be in the braking state. Due to the non-pressure oil action of the control oil circuit, the hydraulic cylinder (hydraulic motor) is locked. The locking effect of the hydraulic lock depends on the shape of the valve plug and the structure of the valve. If the valve plug adopts the ball valve type or the slide valve type, the leakage will still be unavoidable, that is, the oil may leak through the gap generated by the valve core or the gap between the valve core and the valve body. Therefore, the hydraulic lock valve core used in the truck crane should use the core with good sealing performance, even if it is used for a long time, it can guarantee the oil leakage. According to the working condition of the truck crane, the IY-F high pressure hydraulic lock with unloading spool should be selected. For the leg oil circuit, there are two locking requirements for support locking and suspension locking. According to different oil passages, each leg can use a one-way hydraulic control check valve, a one-way hydraulic lock that can only act as a one-way lock, or a bi-directional hydraulic pressure that is formed by two hydraulically-controlled check valves that are cross-connected. lock. The latter scheme is generally used. Each leg lock must be set independently. (2) Series balance valve in the return line The balance valve is essentially a combination valve consisting of a one-way valve and an externally controlled internal-discharge type sequence valve. Its installation position and locking principle in an automobile crane are the same as that of a hydraulic lock, ie, it is installed in a return oil circuit. Shut off the oil circuit after braking. If there are no other special requirements for the oil circuit, hydraulic locks with relatively low prices should be used as far as possible. (3) Improve the tightness of hydraulic components The installation of hydraulic locks or counterbalance valves in the oil circuit does not necessarily ensure that the mechanism can be locked after braking, and the tightness of the hydraulic cylinder (hydraulic motor) is also a key factor that restricts the locking effect. There are two types of leaks in the hydraulic components: internal leakage and external leakage. Leakage in the hydraulic cylinder is not easy to detect, and it will cause the legs to retract, the arm to expand and contract, and the amplitude 3 mechanism can not lock and sink. Therefore, to improve the sealing effect of the hydraulic cylinder, the key is to solve the internal leakage problem that occurs inside. In general, the amount of oil leakage inside the hydraulic cylinder of a truck crane should be strictly limited. During the safety inspection, the piston's moving distance under the specified rated pressure shall not exceed 0.5 min within 10 min. Exceeding this value indicates that the sealing performance is not good. Replace the new Y-ring in time. (4) Lifting hydraulic motor external brake It is difficult for the hydraulic cylinder and the hydraulic motor to cause internal leakage for a long period of time. The leakage of the seal after the seal is worn is unknowingly produced. In this way, if the lock is tight, only one method of installing the brake can be used, and it can only be applied to a hydraulic motor that lifts and lowers the hoist. Others, such as boom extension and contraction, and amplitude change, cannot be used. The brake acting on the lifting mechanism is actually a small single-acting single-acting hydraulic cylinder. The brake is normally closed and the braking force depends on the spring force in the cylinder. In order to obtain the desired locking effect, it is of course desirable that the greater the spring force, the better. However, if the excessive spring force increases the energy consumption of the brake release, the external brake is an auxiliary measure of the locking scheme. 2, speed limit in sports Due to the long crane lift, boom telescoping, and jib boom lengthening, the acceleration due to gravity in the mechanism or load down process is also a prominent issue. The speed limit of truck cranes usually adopts the following two methods. (1) Series balance valve in return oil circuit The balance valve not only locks but also limits the speed. When the mechanism or load falls, the sequence valve in the balance valve can balance the action of the valve core to maintain the return flow of the hydraulic cylinder (hydraulic motor) in a stable state, so that the hydraulic cylinder (hydraulic motor) maintains an even speed motion. In order to obtain a uniform rate of descent, two points must be taken into account when designing the system: First, instead of balancing the valve, it is not possible to use a common one-way valve in combination with an externally controlled internal leakage sequence valve in order to save costs. This is because the balance valve is a combination of a one-way valve and an externally controlled internal leakage sequence valve, but its sequential valve has increased the double-layer spring, damper orifice, etc. to damp the valve core; the second is the control of the balance valve. The throttle valve must be connected in series in the oil circuit to make the spool of the sequence valve act “hysteresis†without changing its speed due to minor changes in the external pressure. In rate-limiting schemes, the use of balancing valves is the best and is the preferred method. (2) Speed ​​limit with manual reversing valve Among all the reversing valves, only the manual reversing valve can commutate at the same time, and the size of the opening of the control valve can be combined with the effect of the limited speed and throttling. Therefore, when the downward acceleration phenomenon occurs in the crane mechanism or the load of the truck, it can be solved by reducing the opening degree of the valve opening by the driver by reducing the pulling degree of the manual reversing valve handle. Of course, due to the shaking of the driver's hand, the speed limiting effect of the manual directional valve is not ideal, but because the loading and unloading speed of the truck crane is often constantly adjusted according to the specific conditions of the construction site, the movement of the mechanism is often not continuous. Intermittent operation, so a skilled driver can still receive a certain speed limit effect when manipulating manual reversing valve. In short, for the crane crane lifting, boom telescopic, boom boom amplitude 3 mechanism both lock and speed requirements, should use a balanced valve that can meet both the locking and speed limit requirements, and then mechanical braking .
Inspection items and performance indicators (1) The minimum dimensions of the strength, stiffness, stability, and structural parts of a crane in a corrosive working environment, and the anti-overturning stability shall comply with gb3811-83 "Crane Design Code". (2) The basic parameters of the truck crane shall comply with the provisions of jb/t1375-92 "Basic parameters of truck cranes and wheel cranes". (3) The safety performance of a truck crane shall comply with the provisions of gb6067-85 "Safety Regulations for Hoisting Machinery". (4) The design of the structure, mechanism, and electrical of the crane is carried out in accordance with gb3811-83 "Crane Design Code". (5) The stability of the crane crane shall comply with the provisions of gb6068.3-85 "Determining the Stability of the Test Regulations for Truck Cranes and Tire Cranes". (6) The rated lifting capacity table, the requirements and representation method of lifting height curve and performance parameter label shall comply with the provisions of jb4031-85 "Truck and Tire Crane Label". (7) The installation and commissioning of the crane safety device shall be carried out in accordance with the provisions of zbj80002-86 Safety Regulations for Truck Cranes and Tire Cranes. (8) The performance indicators of truck cranes shall comply with the requirements of zbj80003-87 "Technical Requirements for Truck Cranes and Tire Cranes". (9) Inspection methods for truck cranes: Press jb/sq1-87 "Product Quality Classification of Truck Cranes and Tire Cranes", jb4030.3-85 "Test Specification for Truck Cranes and Wheel Cranes", gb6068.1-85 "Cranes and Tire crane test specification general requirements, gb6068.2-85 "car crane and tire crane test specification test" and other standards. Product type test according to jb4030.1-85 "Operational Reliability Test for Truck Cranes and Tire Cranes", jb4030.2-85 "Testing Reliability of Truck Cranes and Tire Cranes", gb6068.4-85 "Motor Cranes" Tire crane test specification structure test "and other standards.
Safe operation of the crane is prohibited in front of the operation, that is, the center of gravity of the hook must not exceed the connection between the center of rotation and the center line of the front leg (left and right) when lifting. In the event that the lifting weight indicator device is faulty and cannot be used, the lifting capacity shall be determined according to the provisions of the lifting performance table, and the operation behavior of the crane must be regulated to ensure safety. When lifting heavy objects, it is not allowed to drop the arm; when the arm must be thrown down, the heavy objects should be put down to raise the operation again; when the arm falls, the throttle should be small, and when the arm is lifted, the throttle should be large; the rotation motion should be steady, and no sudden stop is allowed; before the operation It is necessary to carefully inspect and prohibit the use of unqualified steel wire ropes and lifting chains; when lifting heavy objects, it is not allowed to drop the arm; when the arm must be dropped, the heavy objects should be put down and raised again; the throttle should be small when the arm falls.
Packing, storage, transportation and ordering items The truck cranes are generally packed in bare containers, but they are painted with anti-rust oil to prevent rusting during storage and transportation. The relevant boring heads and markings are all hung on or printed on the surface of the truck cranes. Iron plate. When exporting truck cranes sign a specific export contract, the contents shall include: product type, quantity, technical specifications, special use requirements, packaging and transportation conditions, delivery date, payment methods, quality assurance, claims and arbitration and other terms.
Development Trends of Truck Cranes Domestic Development Trends The production enterprises of China's auto cranes need to do many things in order to survive and develop in this field. Due to the increase in market demand, they also require continuous innovation by manufacturers to ensure the performance of cranes. On the basis of it, we must continue to develop new products with larger tonnages to meet the needs of the market. Only in this way can we obtain nutrients and vitality from the market so that we can survive, develop in survival, and grow in development. The main trends should be the following: Expand product variety Within the enterprise, a comprehensive product research and development system should be established to enable serialization of products and complete varieties. A complete series of large, medium and small scales should be formed, and the number of products should be increased so that the scale of production can be continuously expanded. Increase lifting torque At present, most of the auto cranes produced in China are small and medium tonnage cranes with a capacity of 50 tons or less. With the development of society, the demand for large and flexible mobile cranes is increasing. This is the nutrient for the development of automobile cranes. So increasing the moment is imminent. Increase crane function With the rapid development of the national economy, users have more and more requirements for the use of truck cranes. They hope to be able to use more than one vehicle. They are not only used when carrying heavy objects, but also meet the needs of different environments and types of work. These are all future developments Find the direction. Make your own brand At present, China's auto crane production companies lack their own professional researchers and development teams, but instead imitate others' lives. The finished product has no development direction and competitiveness. The globalization of the economy in the future and a series of problems caused by this will transfer the competitive means from the traditional product and price levels to the brand competition. Therefore, major auto-manufacturing companies should strive to build their own brands so that they can grow and develop. Create self-occupied space to occupy the market China's major automobile crane manufacturing enterprises must continue to innovate, boldly carry out reforms that run urgently and intelligently, face the market, and structure Optimization, personnel restructuring, introduction of equipment, hard technical research and development, and occupying the market under the premise of continuous self-improvement. Foreign Development Trends Design, Manufacturing Computerization, Automation In recent years, with the widespread use of electronic computers, many foreign crane manufacturers have increased from the application of a crane aided design system (CAD) to the application of a computer for the design of crane modules. The modular design of the crane module is not only a reform of the design method, but also will affect the technology, production and management level of the entire crane industry. The replacement of old products will speed up the development of new products. For the improvement of the crane, only a few modules need to be changed; the design of a new crane requires only new and different modules to be combined, which improves the degree of generalization and enables the single-piece and small-volume products to be converted into relatively bulk module productions. Less modular forms, combined into different specifications of the crane, to meet market demand and enhance competitiveness. Innovation and Application of Crane Control Elements The positioning accuracy of the crane is an important requirement for the crane. Most of the cranes are equipped with corner encoders, gear chains, laser heads and steel plate holes. The positioning accuracy is usually ±3mm. Accuracy above 1mm requires additional positioning systems. Improvements in hoisting speeds and brakes for cranes are based on the use of low-speed crane hooks for precise positioning and the crane's braking system is also micro-processed for control and monitoring. The remote control system is used for automobile cranes and other mobile cranes. The system includes a controller on the controller and a receiver mounted on the crane. The controller has an electromagnetic radiation generator, a receiver and a crane. The transmission of the operating mechanism of the transmission is connected. The use of a remote controller not only saves manpower, increases work efficiency, but also improves the operator's working conditions. The distance detection anti-collision device of the crane adopts a radio signal anti-collision device. The anti-collision system is composed of a three-phase system and is used to monitor the distance of the front end of the crane. Generally, a warning signal is issued first, and then the vehicle speed is reduced to 50%. Finally, the motor power is cut off and the cart is braked.
The application of new materials and new processes Due to the application of new technologies in steel industry, the quality of steel products can be improved. When designing the strength of crane girders, higher allowable stresses can be used instead of higher safety factors in order to reduce the crane material. The amount of use reduces the weight and price of the equipment. The manufacture of components such as Wanda slewing bearings for cranes also benefits from the continuous production of new materials, making the cranes more light and better. In terms of machining, a large number of precision castings with less cutting are used, in particular aluminum alloy castings, processing equipment used in a large number of high-precision, high-efficiency machining centers, numerical control automatic machine tools, etc., and the quality is ensured, and labor productivity is reduced, and the productivity is lowered. The cost, at the same time, uses machinery instead of manual operations such as welding manipulators and manipulators in mechanical lines. The future development of foreign cranes is toward professionalization, standardization, and serialization. Only in this way can the fastest variety of products be manufactured and assembled. [2]
compression fittings 's ring has double anneal,It is much better for seal.compression fittings,Connex compression fittings,Plumbing compression fittings
compression fittings,Connex compression fittings,Plumbing compression fittings
Taizhou Runde Company , https://www.smartfittings.com