Mold and machine tools are two closely related industri […]
Mold and machine tools are two closely related industries. Therefore, the continuous innovation of mold technology promotes the continuous improvement of the machine tool industry. With the acceleration of the upgrading of consumer products, the mold technology is constantly innovating and developing, and the requirements for the accuracy of the produced products are becoming more and more stringent, and higher and higher requirements are put forward for the production efficiency and quality of the mold. The shortcomings of spark machining molds such as low production efficiency and unstable quality are gradually exposed. In order to realize the high-speed machining of the mold cavity and its related parts, three major requirements are put forward for the machine tool.
In order to realize high-speed machining of mold cavity and related parts, the machine tool needs to have the following characteristics:
1. As the mold is developing towards large-scale, molds of several tons to dozens of tons are very common, so the machine tool table must be able to bear heavy weight, which requires the equipment to have the characteristics of large load-bearing and high rigidity, and it must have enough Large table size and working stroke are compatible with it. In addition, the strength and hardness of the mold material are very high, and the mold cavity is often processed with a small-diameter end mill with a large elongation, so chattering is prone to occur during the processing process. In order to ensure the machining accuracy and surface quality of parts, high-speed machine tools used for mold manufacturing must have high dynamic and static stiffness to improve the positioning accuracy, tracking accuracy and vibration resistance of the machine tool.
2. High-speed and high-power high-speed machining is the development direction. High-speed milling has shown great advantages in mold processing. In order to adapt to the processing of the mold cavity surface, the radius of the tool should be smaller than the minimum circumferential radius of the cavity surface to avoid "interference" between the tool and the workpiece during the processing. Due to the small diameter of the tool, the spindle speed is required to be very high. The spindle speed of foreign high-speed machining machine tools has reached 40,000 to 100,000 r/min, and the rapid feed rate can reach 30,000 to 60,000 r/min. The roughing and finishing of cavity and other parts of mold parts are often completed in one clamping of the workpiece, so the spindle power must be large. The spindle power of medium-sized mold milling machines and machining centers is often 10-40kW, and some are even higher.
3. Multi-axis linkage and good deep cavity comprehensive cutting ability. Most mold cavities are composed of complicated spatial six-curved surfaces and grooves, and many molds have deep cavities. In order to achieve high-precision, high-speed and high-stability machining of 3D surfaces, the machine tool needs multi-axis linkage and has a good comprehensive cutting ability for deep holes. A five-axis linkage machining center can be used. In addition to the linear motion of the three coordinates, there are also two feed motions of the rotating coordinates. The milling head or worktable can continuously rotate and feed in multi-axis linkage, which is suitable for processing mold parts with complex cavity surfaces.
It can be said that compound processing is one of the development directions of mold processing. Although the machining center has been able to combine many machining processes on one machine tool, it still cannot fully adapt to mold processing. It combines machining with electrical, chemical, ultrasonic and other different principles of processing methods, and has more than two process characteristics. The composite processing will have broad prospects in the future mold manufacturing.