Under normal circumstances, the production of a mechanical part, from the blank to the finished product, must be processed by some (one or more) processing methods (such as stamping, welding, cutting, grinding, special processing or turning, milling, Drilling, boring, tooth machining, etc.) multi-process (such as turning outer circle, turning end face, turning groove, turning inner circle, turning thread, turning cone surface, etc.) in turning. Since different process methods have different processing principles and characteristics, and different processing procedures have different processing purposes and requirements, they are implemented with different processing equipment. Therefore, in traditional manufacturing, the manufacture of a part is often Need to have a variety of different processing equipment to complete. This not only increases the number of equipment and the floor space of the production plant, thereby increasing the investment of the enterprise, but also affects the processing because the workpiece needs to wait, transfer, check and reposition and clamp between the process and process equipment during the production process. Accuracy also increases a lot of non-processing time. Some experts have analyzed that this part of non-processing time will account for about 70% to 95% of the total production cycle of parts, thus greatly restricting the improvement of production efficiency.
In order to improve production efficiency and reduce non-processing time, people have long ago concentrated some processing procedures with similar or similar processing principles and requirements, and even different technological processes to one or a few pieces of equipment. This idea of compound machining of parts after one clamping, combined machining machine tools and multi-tool semi-automatic hexagonal (turret) lathes that appeared in the process of mechanical automation production, are its initial manifestations. Because the combined machine tool is based on some general components (such as power head, sliding table, base column, rotary table, etc.) etc.) specially designed fixtures, multi-axle boxes and some tools are assembled, which can complete all or most of the workpieces for a specific workpiece, such as automobile engine casing, box cover or gearbox body, etc. Processing procedures, including plane milling, drilling, boring, reaming, tapping, etc.; while the multi-tool semi-automatic turret lathe, according to the process requirements of the workpiece to be processed, installs the required cutting tools on its turret tool post. , that is, it is possible to process all or most of the processes of a specific shaft or disc or kit in one clamping, such as turning inner and outer cylindrical surfaces, end faces, grooves, chamfering, machining internal and external threads, etc. Therefore, both the combination machine tool and the multi-tool semi-automatic turret lathe embody the concept of centralized processing for compound machining, which greatly reduces non-machining time, thereby significantly improving productivity. However, these machine tools belong to the category of rigid automation. When the processing object is changed, the equipment must also be replaced or reconfigured, which requires a large amount of time and capital investment, so it is only suitable for medium and large-scale production of a single variety of parts. , not suitable for single and small batch production of multi-variety parts.
With the emergence of CNC machine tools and the increasing development and performance improvement of CNC technology (including CNC servo systems, functional components and programming, software, etc.), the flexible automation capabilities of CNC machine tools have been greatly enhanced. The market demand for multi-variety and small batch production is increasing, which provides a broad world for the development of CNC machine tool processing complex. In fact, shortly after the advent of CNC machine tools, the first boring and milling machining center appeared in 1958, and compound machining has become one of the important technical development directions of CNC machine tools. CNC composite processing machine tools to meet the needs of today's market for efficient and low-cost production of multi-variety and small-batch parts.