Un laser
new energy car welding
With the rise of green development philosophies, new energy vehicles are breaking the pollution and energy waste problems of traditional gasoline vehicles. This article examines the current development status of new energy vehicles, and the new welding technologies and applications under intelligent manufacturing requirements. The goal is to establish a foundation for future new energy vehicle production and application.
Keywords: intelligent manufacturing, new energy vehicles, welding technology, laser welding
Introduction
Most countries still rely heavily on oil consumption for economic and social development. However, oil is a non-renewable resource with very limited reserves. Continued usage at this rate will be fatal to global economic growth, posing even greater challenges. China became the world’s second largest new car consumer market after Japan in 2006, second only to the United States. Since the new century, people have gradually realized the importance of green development and the severity of the energy problem. Energy-related issues have also been included in China’s energy security policy.
New Energy Vehicles and Welding Technologies
New Energy Vehicle Basics
Traditional gasoline vehicles powered by oil not only cause serious energy shortages due to consumption, but also adversely affect global environmental deterioration and greenhouse gas emissions. Currently, many pollutants in the air come from car exhausts, such as carbon monoxide, 80% from car exhaust; nitrogen oxides 40%; and 20% to 30% of particulate matter pollution in cities comes from car exhaust. Environmental issues in turn pose serious threats to human health and life, and have attracted the attention of the state. In recent years, new energy-related technologies have gradually matured, and electric vehicles and cars based on new energy sources have also come onto the market, with very significant environmental benefits. Against the background of increasing attention to environmental issues in the future, new energy vehicles will also become a development trend in the future.
The 2010 Shanghai World Expo put forward the goal of green and environmentally friendly development. China’s 13th Five-Year Plan also incorporates the concept of green development into emerging development concepts, paying more attention to the harmonious coexistence of man and nature. The development of new energy has also laid the foundation for the development of new energy vehicles. Different countries have large differences in the technological development path of new energy vehicles. Currently, electric vehicle technology is the mainstream technology in new energy vehicle technologies. Electric vehicle technologies can be divided into lead-acid batteries, hybrid power and pure electric vehicle technologies.
Although electric vehicle technology has gradually matured, there are still some problems, such as manufacturing costs and cruising range still differ from traditional fuel vehicles. Due to differences in batteries themselves, there are problems in terms of volume, weight, power, cost and charging time, which have also become bottlenecks for further development of electric vehicles in today’s society. These problems can be summarized as: very limited cruising range; relatively short battery life; expensive battery costs; and issues with charging stations and charging times that cannot be effectively resolved in a short time.
Welding Technology
Laser Welding Technology
The welding technology most widely used in new energy vehicles currently is laser welding. This new welding technology has also been successfully applied in powder metallurgy, biomedical, electronic packaging, automotive and aerospace. For new energy vehicles, one of the core components is the motor.
The requirements for motors are also very high in the specific manufacturing process of new energy vehicles. Especially in the welding process of prototypes, higher strength and higher precision are required, with less thermal impact. However, the welding operation space angle is very limited during welding, which would be hindered. Compared with traditional welding methods, laser welding has significant advantages in application in new energy vehicles, and will also become an inevitable development trend in the future.
Advantages of Laser Welding Technology in New Energy Vehicles
The application of laser welding technology requires the use of a high energy density laser beam as a heat source, which is a high precision welding method with high efficiency. Compared with traditional welding technologies, the application advantages of laser welding technology in new energy vehicles are mainly reflected in the following aspects:
First, heat input can be minimized, which will continue to reduce the range of the heat-affected zone, resulting in the lowest incidence of adverse effects caused by thermal conduction.
Second, no electrodes are required during laser welding, so there is no need to consider electrode damage or contamination issues. Because remote welding is different from general contact welding methods, it can also reduce wear and deformation effects on fixtures.
Third, laser beams have advantages in focusing and alignment, guided by optical instruments. In the specific welding process, it only needs to be placed at an appropriate distance from the workpiece. At the same time, during the guiding process, it only needs to be between obstacles or around fixtures of the workpiece, with less spatial constraints.
Fourth, in a relatively closed space, that is, an internal gas environment or a vacuum environment, the laser beam can be focused within a very small area, so small area components can be welded. The range of materials that can be laser welded is extensive, and even welding of different types of heterogeneous materials can be achieved.
Fifth, laser welding can easily become high-speed welding, and computer or digital control can be realized. When welding some thin wire materials, there will be no back melting effect as in arc welding, nor will there be effects caused by the magnetic field, so that more precise alignment of the parts to be welded can be achieved during welding.
Sixth, welding of two materials with different properties can be achieved, such as two metals with different resistances.
Seventh, X-ray protection is not required during actual welding, nor is a vacuum environment.
Eighth, if perforated welding is used during laser welding, the depth-to-width ratio of the weld can exceed 12:1.
Ninth, the laser beam can be transmitted to different workstations at the same time by converting the device.
The use of laser welding in the manufacturing of new energy vehicles can significantly increase its social and economic benefits, while improving the quality of welded joints and significantly improving stability, reducing accidents and losses caused by joint problems, and lowering costs from another perspective. In addition, the application of laser welding technology in the manufacturing of new energy vehicles will also solve the environmental pollution problems of traditional welding technologies, electromagnetic radiation and other issues, with significant social benefits.
Application of Laser Welding Technology in New Energy Vehicle Manufacturing
Welding Rotor and Stator Stampings
Various processing technologies such as bonding, welding, caulking and riveting are used in the specific welding process. Among these processes, the welding process is a lower cost and higher quality method. Welded parts require silicon steel sheets as the raw material for the stator core, and after related processes such as cutting and punching, they are firmly stacked and pressed, and then welded at a certain distance on the outer wall of the stator to melt the silicon steel sheet surface to form a new whole. In the process of welding the stator of the motor, the technology has also progressed from strip electrode arc welding and carbon dioxide gas shielded welding to the current laser welding. From the perspective of weld process, laser welding is more ideal, because the initial two welding methods have shortcomings in splashing and poor forming. The material for stacking motor stator sheets is usually selected from hot rolled or cold rolled silicon steel sheets with good weldability. If laser welding is used, it will help improve productivity while improving production safety conditions, reducing the adverse damage caused by undesirable oxides to the human body. In addition, by using a computer to control the output of the laser beam, the stator can meet the requirements of the weld seam, and can be completed in one or two welds, saving time and greatly reducing variability.
Welding Rotor Shaft Collar and Rotor Shaft
When welding these two components, the welding method used is generally tungsten argon arc welding and carbon dioxide gas welding, but welding will produce greater variability, and the area affected by heat is also greater. The heat waves generated during welding also affect the magnetic steel in the motor body. If laser welding is used, it will increase density, concentrate energy, accelerate speed, improve efficiency, reduce deformation, and reduce heat effects. The effect is more obvious.
Welding Clutch and Rotor Shaft
When welding these two parts, it is necessary to ensure that the fusion depth of the weld exceeds 4mm. Tungsten argon arc welding and carbon dioxide gas welding can achieve the required weld seam, but the variability is large. Other methods will have an adverse effect on the accuracy of the workpiece, so small power laser welding can be used to improve the welding and assembly accuracy of parts and better control the organizational properties of the weld area.
Welding Sealed Aluminum Alloy Casing
The connection between the motor body and the aluminum alloy casing is usually bolted or riveted to reinforce and seal. However, the traditional sealing method will gradually weaken due to aging of the gasket, adversely affecting the overall performance of the motor. If seamless welding is used instead of traditional welding during welding, the weight of the motor body is reduced, the production cycle is shortened, and the sealing performance of the motor is improved. For other materials, the weldability of aluminum alloy itself is poor, so laser welding technology or tungsten argon arc welding technology is required.
Conclusion
The emergence and application of new energy vehicles is in line with the current concept of green development. However, their production and promotion are also restricted by many factors. Welding technology is an important part of electric motor manufacturing for new energy vehicles, and the choice and application of welding technology will affect the final welding effect. This article mainly explains the advantages of laser welding technology, such as meeting the welding needs of different materials, and utilizing the advantages of the laser itself to achieve 360 degree dead angle-free welding, which is impossible with traditional welding technologies. It also analyzes the specific applications of laser welding technology in new energy vehicles, and points out that it will bring better social and economic benefits. In the future application of new energy vehicles, welding technology will also achieve new developments and updates to ensure the quality of new energy vehicles.