In today's sedan manufacturing industry, the development cycle of new products is constantly shortening, and the cost is also constantly decreasing. Data shows that ten years ago, there was a demand for sedan products with a four-year development cycle; It only takes two years to complete today. In addition to the leading new product development methods, virtual production, synchronous engineering and other advanced development skills adopted by car manufacturers, it is important to benefit from the efforts of equipment suppliers who provide production equipment for car manufacturing, especially those who supply various CNC lathes. These CNC lathes allow car manufacturers to supply products that meet market demand at the fastest speed.


Classification and Characteristics of CNC Lathe Processing


There are many types of CNC lathe machining; In terms of major categories, there are specialized CNC lathes for processing and general CNC lathes for processing; In terms of processing varieties, there are CNC lathes for processing shells, CNC milling machines and machining centers, CNC lathes for processing shafts, turning centers, cam CNC grinders, etc; In terms of control requirements for CNC lathe machining, there are single axis CNC sand belt polishing machines, five linkage CNC gear cutting machines, and CNC rolling cutters; From the complexity of control, there are simple CNC and multi-channel CNC; In terms of driving methods, there are stepper motors, DC servo motors, AC synchronous servo motors, AC asynchronous servo motors, and linear motors; In terms of spindle drive methods, there are DC spindle motors, AC spindle motors, and AC spindle motors; From the perspective of position feedback methods, there are fully closed-loop feedback, semi closed-loop feedback, open-loop control, and so on.


Good flexibility in CNC lathe machining High adjustment and high processing accuracy have long been the focus of car manufacturers, and they began to enter the field of car parts production in the 1960s. Due to its high cost, poor system functionality and efficiency, it has not been widely used. In the 1990s, with the intensification of market competition; Multi variety production maximizes the satisfaction of diverse market demands, until it meets the needs of every CNC lathe processing user, becoming the goal pursued by car manufacturers. Flexible production units with CNC machine tools as the main body are widely used. There are two key development directions for CNC machine tools today:


High speed CNC lathe machining achieves high efficiency with high speed. The current international level is spindle speed ≤ 25000rpm, acceleration and deceleration ≤ 2.5g, and fast movement ≤ 160m/min. To achieve this new level, the drive, mechanical transmission, mechanical structure, and cutting tools of CNC machine tools need to be greatly improved. The spindle of the machine tool must use an electric spindle, and the main bearing is generally made of ceramic bearings. The difficulty lies in cooling and lubrication, and the service life is generally 20000 hours. The drive is generally driven by a linear motor with a linear guide rail (or a static pressure guide rail), with a speed of 90m/min. The 1g machine tool is also driven by a double servo motor with a large pitch double ball screw pre tensioning scheme. The mechanical structure generally adopts a frame box structure. The cutting tool is made of high hardness and high heat resistance, and the handle is made of HSK.


To solve the contradiction between flexibility and high efficiency, specialized CNC lathes or specialized machine tools can be used for specialized machining. At present, the production of European and American cars mostly adopts agile production systems composed of high-speed machining centers, which can produce 100% flexible mixed flow multi variety products. This system consists of multiple flexible machining units called island type, each island is composed of multiple similar machine tools and machine arms connecting the machine tools, and information exchange is carried out between the machine tools and the pallet with electronic storage. It is worth noting that these equipment suppliers not only possess proprietary skills in equipment manufacturing, but also attach great importance to the development of car manufacturing processes. They are able to provide turnkey projects to users and have their own system development capabilities. The reliability index of the machine tool is extremely leading, with a single machine operating rate of over 98%. By adopting this production system, the industrial launch cycle of new products by car manufacturers is greatly shortened.


After more than 20 years of reform and opening up, the use of CNC lathes in the production of car parts in China has become increasingly widespread. But most of them are imported machine tools from Europe, the United States, and Japan. The characteristics of European, American, and Japanese machine tools are: good reliability and low failure rate; The design of human-machine interface emphasizes humanization; Equipped with active measurement and compensation system; Can supply processing units with automatic loading and unloading devices; Modular design of machine tools. Although there are many domestic CNC machine tool manufacturers, in terms of variety, there are still many low-level general-purpose CNC lathes. For multi axis CNC machining centers suitable for large quantities of car engines, transmissions, and chassis main components, there are few varieties and most of them have not undergone large-scale production tests.