Anshan Heli Laser Equipment Co., Ltd.
National Service Hotline : 400-641-6888
Address: No. 368 Qianshan Road, High-tech Zone, Anshan City
Dongguan Heli Laser Equipment Co., Ltd.
Address: No. 48 Wenxiang Road, Xiaoxiang, Wanjiang District, Dongguan City, Guangdong Province
Contact: Mr. Yang
The development of laser processing technology has driven the progress of rail passenger car manufacturing. At the same time, the requirements of high speed and light weight of rail vehicles have continuously provided new topics and research directions for laser processing technology, which has led to the improvement of product structure. The application of technology cannot have the rapid development of modern multi-variety, multi-series high-speed and urban rail passenger cars.
Laser cutting technology application in rail vehicle manufacturing 1. Laser cutting machine technology As a flexible processing technology, laser cutting machine has the advantages of high precision, high efficiency, small thermal deformation and strong adaptability. At present, domestic and foreign rail vehicle manufacturers Laser processing technology is commonly used to process metal sheets such as stainless steel, carbon steel, and aluminum alloys. The processed products mainly include the metal plate parts of the car body, bogie, and interior parts. Most of them are two-dimensional plane cutting, and the outlines and holes of the parts are processed by laser cutting to obtain higher accuracy and cutting section quality. The main equipment used in laser processing is laser cutting machines of various specifications. Each manufacturer has multiple laser cutting machines according to different production capacities. In general, carbon steel and stainless steel plates generally use CO2 laser cutting machines or solid laser cutting machines ; aluminum alloy plates use solid-state laser cutting machines ; for carbon steel plates with a thickness of 10 to 20mm, CO2 laser cutting machines are commonly used, which can achieve High cutting speed and good cross-section cutting quality.
Due to the application of laser processing technology, flexible processing has been realized, replacing a large number of stamping dies, shortening the preparation cycle for stamping production, and saving a lot of die costs. Therefore, laser cutting has become the metal sheet cutting material in rail vehicle manufacturing at home and abroad. The main means are shown in Figures 1 and 2.
There are mainly three types of indicators for evaluating the accuracy of laser cutting machines : ① Cutting section indicators: There are mainly section roughness, cutting slope, slag hanging and thermal deformation. ② Geometric tolerance index: There are hole roundness, position degree, repeat accuracy and dimensional error. ③ oxide layer and heat affected zone. Refer to national standard: GB / Z18462—2001 Laser Processing Machinery—Metal cutting performance specifications and standard inspection procedures.
There are many reasons that affect the accuracy of laser cutting in actual production, such as equipment accuracy, cutting parameters, gas purity, material type, thickness, and environmental factors. When selecting equipment, the accuracy that the equipment can achieve is measured according to the accuracy test data and curves provided by the equipment manufacturer. In general, the laser beam positioning accuracy of laser cutting is ± 0.03mm; the cutting surface roughness Ra = 12.5μm; the actual cutting error is 0.1 ~ 0.3mm.
2. Laser welding
As a high-energy beam welding method, laser welding has been widely used because of its stable quality of welding joints, fast welding speed, and small welding deformation. In terms of rail vehicles, in recent years, it has mainly been splicing welding of carbon steel and stainless steel car body steel structures. The advantages are high welding efficiency and small welding deformation, which improves the overall flatness and appearance quality of the steel structure of the vehicle. . It mainly adopts laser welding machine or welding robot. The laser generator uses CO2 laser or solid-state laser generator. The corresponding control methods and auxiliary devices are used to achieve butt welding of steel plates.
Stainless steel laser semi-penetration overlay welding technology has begun to be popularized on rail passenger car bodies, and its main purpose is to replace the resistance spot welding of rail vehicle outer plates and skeletons. Due to the traditional resistance welding process, there are unavoidable bumps on the surface solder joints. In addition, the car body of the spot welding structure has poor sealing performance, and it cannot be widely used for high-speed EMU car body products. Using semi-penetration overlay welding technology can achieve the goal of no welding deformation and discoloration on the outer surface of the lower plate after welding, and produce stainless steel car body products with beautiful appearance and no coating, and through laser welding process, the vehicle's static strength and fatigue strength The improvement, the reduction of the car body mass, and the good sealing performance make the composition of a high-speed moving car using a stainless steel car body feasible. The thin plate stainless steel body laser welding technology can be applied to the manufacturing of high-speed EMUs and urban rail cars, which greatly improves the grade of products and enhances the market competitiveness of enterprises. The market prospect is very optimistic.
Development trend of laser processing technology in rail vehicle manufacturing 1. Laser cutting technology Three-dimensional laser cutting technology has just been applied in the domestic rail vehicle manufacturing industry. It mainly performs cutting and cutting of various three-dimensional stamping parts, and is generally equipped with robots, fiber lasers, and exchange work. Table, closed-circuit real-time monitoring display, closed cutting room, dust removal and programming system. Able to realize three-dimensional cutting and hole cutting of various three-dimensional workpieces; the configured exchange table can perform workpiece exchange and cutting to improve efficiency; offline and teaching programming to improve cutting accuracy; and realize safety and environmental protection. The application of this equipment in production solves the three-dimensional cutting of various complex workpieces, replacing the backward toothless, manual plasma cutting process, which not only improves product quality, but also solves the problem of environmental pollution, as shown in Figure 7.
In addition, with the continuous development and wide application of laser cutting technology, laser processing technology will present the following development trends in rail vehicle manufacturing:
(1) The large size of laser cutting equipment for the processing of large and long pieces, especially the laser cutting after the component parts, will improve the processing capacity and quality of large workpieces.
(2) Specialization of laser cutting equipment For carbon steel, stainless steel, aluminum alloy materials, especially different thickness materials, different cutting equipment is used; for example, aluminum alloy cutting uses fiber lasers with appropriate power, which reduces the damage to the equipment and improves the quality. ; Thick carbon steel plate is cut by CO2 laser to improve speed and section quality; thin plate is cut by fiber laser with high efficiency and low cost.
(3) Further innovation and improvement of laser cutting technology With the increasing demand for laser cutting technology due to the diversification of demand, it is bound to promote the revolution of laser cutting technology, and more advanced technologies and equipment will emerge as the times require. At the same time, the wide application of laser cutting technology will also provide effective data and experience for the innovation and improvement of laser cutting technology. In short, further improvement in cutting quality will be an endless goal.
2. Laser welding
Laser-arc hybrid welding is a high-energy beam welding method developed in recent years. Laser and arc simultaneously input energy to the welding zone and act on the weld zone at the same time, giving full play to their respective advantages, forming a new efficient welding heat source. . At present, laser-arc hybrid welding technology has been applied in automobiles, ships, aerospace, petroleum pipelines, etc .; laser-MIG hybrid welding has a greater penetration depth than laser welding and arc welding, faster welding speed, and better weld formation ratio. The laser welding is good, the heat input is small, the welding input is small, the welding strength loss is small, and the joint gap is not sensitive. This technology has no practical application cases in the domestic rail vehicle industry, only relevant process test development has been carried out and certain results have been achieved
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