Improve mold processing capability and deepen the performance of CNC machining equipment

Assistant General Manager and Technical Director of FAW Mould Manufacturing Co., Ltd.   Li Yue

At present, the gap between the main domestic automotive mold companies and the international level in the main processing hardware is rapidly shrinking, mainly reflected in the recent years, domestic automotive mold companies purchase a large number of advanced CNC equipment, including three-axis to five-axis high-speed machining machines, The large-scale gantry CNC machining center, advanced large-scale measuring and debugging equipment and multi-axis CNC laser cutting machine have greatly improved the level and capability of domestic enterprises to produce automobile panel moulds, and even some enterprises have reached the world advanced synchronization level.
In the aspect of CNC machining, taking FAW Mould Co., for example, most of the advanced processing equipment for automotive molds is imported from abroad. For example, two gantry-type high-speed five-axis linkage machining centers imported from Italy RAMBAUDI and JOBS have a working surface of 2500mm*5000mm and a maximum spindle speed of 20,500 rpm. Powerful milling and high-speed milling can be used to quickly change the spindle head. More than ten large-scale SNK CNC milling and machining clusters introduced by the machine are equipped with a tool magazine. According to the function distribution, high-speed milling head, powerful milling head, universal swing angle milling head, 30° swing angle milling head, 90° side shaft milling head, etc. The functions of automatic head change and automatic tool change can be realized through the control of the machining program, and some molds have completely realized the unattended automatic CNC machining. For large molds, whether it is the mold three-dimensional surface, the mold structure table, or even the drilling and tapping, all adopt programmed CNC machining. At the same time, it is equipped with more than ten small CNC machining centers, mainly used for processing small parts. These advanced CNC machining equipments have much room for improvement in terms of functional applications and processing efficiency:
1. Development and application of advanced functions of advanced numerical control equipment

We have five-axis linkage CNC equipment for more than ten years, but rarely use five-axis linkage for CNC machining. On the one hand, there are fewer mold parts that can be processed by five-axis linkage CNC machining; in addition, due to the characteristics of single-piece production of the mold, five-axis linkage requires high processing safety, and five-axis programming is relatively difficult; more importantly, five-axis linkage programming Little experience, lack of skilled technicians for five-axis linkage programming. Many advanced mold companies in foreign countries use flat-bottom knife five-axis linkage processing such as top-cover molds, CNC finishing efficiency can be increased several times or more; all-aluminum CUBBING inspection tools use a large number of five-axis linkage processing methods to ensure the accuracy of parts. Corresponding to the high-speed machining development such as NURBS processing mode, although the machine tool has corresponding functions, it has almost never been applied due to the lack of corresponding post-processing programming means.
2. Multi-variety numerical control system exists at the same time, affecting processing efficiency

We have applied CNC machining technology for more than 20 years, and these CNC machine tools are also the current scale of multi-batch procurement. Its CNC core control system is also diverse. Just like our company has control systems such as FANUC, FIDIA, and Siemens, even the same FANUC system has multiple versions. This on the one hand increases the difficulty of processing management, affects the efficiency of programming, and at the same time affects the processing quality due to the inconsistent code. For example, circular interpolation, fixed cycle, etc., which are often used in numerical control, have different codes for various control systems. Many manufacturers' countermeasures are either outputting multiple versions of the same program or completely canceling circular interpolation. The instruction is replaced by linear interpolation, which seriously affects the processing efficiency and processing quality.
There are also a wide variety of inspection equipment configurations. We have a number of large gantry three-coordinate measuring machines (COORD3), Norwegian Maidoono laser pointers, portable articulated arm measuring machines, ATOS white light scanners, etc. Different manufacturing stages and even different parts of stamping parts have their own characteristics. For example, the three coordinates of Longmen are suitable for detecting the characteristics of holes and faces with high precision requirements. The white light scanner is suitable for detecting three-dimensional profiles. The laser pen is suitable for the adjustment and detection of workpieces at the same time. The use of these devices often needs to be combined and complementary. It should be noted that since the large stamping die has a weight of nearly 20 tons, pay attention to the rigidity of the table when selecting the CMM, especially to avoid the use of the movable table.
"If you want to do something good, you must first sharpen your tools." In short, based on the characteristics of sophisticated, complex and single-piece production of large-scale automotive molds, the manufacture of such molds is bound to use a large number of advanced processing and measuring equipment. The introduction of these devices must also promote changes and upgrades in the series of manufacturing processes and manufacturing processes. By optimizing the processing route, we will conduct in-depth research on many issues affecting mold processing efficiency and processing quality, and continuously improve our mold manufacturing level.