On October 9, 2017, the manufacturing and painting construction of the first car body of Metro Line 4 was completed. This is another very important node in the construction of Changsha Metro Line 4, marking that line 4 has fully entered the vehicle manufacturing stage.
Higher localization level of key train systems
This time, a number of new technologies have been applied to the train of line 4, which is more energy-saving, safer and has a higher level of localization. Key train systems, such as bogie, train control system and traction system, are independently developed by CRRC Zhuzhou Electric Locomotive Co., Ltd. and CRRC Zhuzhou Electric Locomotive Research Institute Co., Ltd.
Car body and painting effect
Friction stir welding and other new welding processes are adopted for car body
The car body is the main structure of the vehicle, which is composed of large section hollow extruded aluminum alloy profiles. On one train, there are 72 kinds of aluminum alloy profiles with different sections, the thinnest part is 2mm, and the thickest part is only 17mm. There are 38 types of welding seams in the whole car body of the train. In order to ensure the strength and safety of the car body, all the long welding seams are completed by the robot, and the welding accuracy is generally less than 1 mm, which is only equivalent to the thickness of the nail piece. Among them, the side wall of car body adopts a new welding process friction stir welding, which uses the heat generated by the mutual movement and friction between the welding head and the welding point to make the welding point reach the thermoplastic state, so as to complete the welding. Because there is no spark during welding, compared with the traditional welding process, it has the advantages of high precision, safety, no pollution, no dust, no radiation and so on.
Metallic paint, frequency conversion air conditioning and LCU technology are adopted for the first time
The trains of Changsha Metro Line 4 are the same as those of metro lines 1 and 2 in operation. They are B-type trains with 6-car formation, 4 motor trains and 2 trailers, and the maximum running speed is 80km / h. At the same time, the car body of line 4 is coated with metallic paint for the first time, which makes the appearance of the train more beautiful, has the unique flash effect and metallic luster of metallic paint, and has better anti-corrosion protection effect on the surface of car body structure. The train circuit adopts the contactless logic control (LCU), which is the first time used in Changsha Metro train. The frequency conversion air conditioning unit is also used in the train air conditioning, which improves the energy saving efficiency and ride comfort of the train.
At present, the first train of line 4 is under assembly. With the orderly development of vehicle manufacturing, the trains of line 4 will be transported to Changsha in the first half of 2018 to meet the general public.