Machine tool manufacturing industry and rail transit facilities seek common development

China's rail transit began with the first major acceleration in the late 1990s after the reform and opening up, and by the eighth acceleration in 2011, China's rail transit experienced a rapid development. Taking Shanghai to Nanjing as an example, it takes 4 to 5 hours before the speed increase. The fastest time is only 1 hour, and the speed has exceeded 350 kilometers per hour. It takes only 5 hours from Shanghai to Beijing. And these high-speed realizations are inseparable from advanced manufacturing technologies and equipment.

Luo Baihui said that the main parts involved in rail transit machining, which are relatively difficult to machine, are bogies for bogies and hollow axle bushes. The other key components are diesel engines. The main components of locomotive diesel engine are complex in structure, high in manufacturing precision, tolerance in shape and position, and high in surface roughness (the accuracy index is mostly in the range of 5 to 7 and the roughness Ra is about 0.4), and requires good interchangeability, such as the body and the crankshaft. The main purpose of the connecting rod and cylinder head is to ensure that the locomotive has good reliability, high durability and high safety factor in high-speed operation.

In terms of diesel engine key components, the relative dimensional accuracy of many components is in the μm class, which was previously unimaginable and cannot be achieved at all.

“Mechanical machining is made up of basic machining methods such as car, milling, planing, boring, drilling, and grinding.” Luo Baihui believes that in the past, different processing processes for different products and the same product, people used a large number of traditional processing functions in a single structure. General equipment such as lathes, milling machines, planers, boring machines, drilling machines, grinding machines, etc., along with the development of technology, the proportion of these common equipment has dropped significantly, and instead it is a single-axis and two-axis linkage-based CNC lathe, Vertical and horizontal machining center CNC machining machine.

With the development of random bed accessories and in-depth research on related technologies, today's CNC machine tools have been dominated by flexible, compound, multi-axis linkage, high precision, and high speed. Such as multi-axis milling and milling center, boring and milling center, follow-type grinder and so on. The performance of the machine tool also features high-speed, high-efficiency machining and intelligence along with the development of tool materials and manufacturing technology, computer software technology, precision measurement technology, and rapid servo drag technology. In addition, in order to meet the user's demand for product production, various types of machine tools with mixed functions and mashup technologies are also produced. Such as: laser and milling (DMG) knead together; milling and grinding (Wollenberg) knead together and so on. Taking the crankshaft as an example, a turning and milling center has replaced machining functions such as car, milling, drilling, expanding, and reaming that could be achieved by 6-7 machines in the past, including all machining of the crankshaft, connecting rod neck, and crank. ,Flange hole processing, keyway processing, thread hole processing, main oil hole and oblique oil hole processing, etc., reduce the number of clamping, improve product accuracy, and at the same time greatly reduce the preparation of trial equipment for new products, machine tools The processing flexibility is greatly enhanced; similarly, a crankshaft follower grinder replaces the original ordinary large-scale cylindrical grinder and the connecting rod-neck crankshaft grinder. One device has the effect of two grinders, and the floor space is only one. grinder.

In addition, CNC online measurement also solves the measurement problems in previous machining. MarpossFENAR-L online diameter measuring device can control the precision of online product processing in real time and set the automatic alarm beyond.

At present, Chinese companies, after introducing advanced machine tools and tools, combine the special products of rail transit with a long process of digestion, absorption and consolidation. Especially for process programming, operators, and even production management personnel, there is a gradual process from unfamiliarity to preliminary grasp to ease of application. Therefore, how to be a good company's technologist to help companies put their equipment and tools into use as quickly as possible and generate benefits quickly - this, in turn, sets a good image for their products. This is a new topic for equipment manufacturers. At the same time, how to quickly master advanced equipment technologies is also a lasting issue faced by Chinese and corporate customers.

The future development of rail transit manufacturing will continue to grow with the development of random bed manufacturing; it will continue to evolve with the different needs of all industries. Green and diversified (to meet the requirements of different users), low noise, low pollution, low fuel consumption, low emissions (to meet Tier IV emission requirements) and high reliability are also targets for the design and manufacture of diesel locomotives. CSR Qishuyan Locomotive Co., Ltd. plans to continue efforts in this direction through international cooperation.