The most commonly used machining method in high-speed cutting is high-speed milling. Using high-speed milling molds to replace EDM molds has the following advantages.
(1) Good processing quality
When machining molds with traditional EDM methods, the physical-mechanical properties of the surface of the workpiece material will be damaged during the local high-temperature discharge ablation process on the surface of the workpiece, and micro-cracks will often be generated on the surface of the cavity, which makes it difficult to ensure the quality of the workpiece . Tapered roller bearing is a kind of rolling bearing, and it is one of the parts widely used in modern machinery. It relies on the rolling contact between the main components to support the rotating parts. Roller bearings are now mostly standardized. Roller bearings have the advantages of small starting torque, high rotation accuracy, and convenient selection. High-speed milling processes parts at a cutting speed about 10 times higher than the conventional milling speed. The blank is cut away from the workpiece before it can be fully deformed, and the residual stress on the surface of the workpiece is very small. At the same time, the spindle speed of the machine tool during high-speed milling is extremely high (8000r/min～100000r/min), the excitation frequency of the "machine tool-fixture-workpiece-tool" process system is much higher than its natural frequency range, and the parts processing process is smooth Shock. Therefore, the machining accuracy of the parts is high, and the surface quality is good. After high-speed milling, the surface quality of the mold cavity can reach the level of grinding, so the subsequent grinding process can be omitted.
(2) High production efficiency
Since EDM is "micro-cutting" by electric discharge ablation, the machining process is very slow. At the same time, the surface roughness of the mold cavity does not meet the requirements of the mold. Often time-consuming manual grinding is required after EDM And polishing molds, so the production efficiency of this process is extremely low. In the machining center or high-speed milling machine, the efficiency of the machining process itself is several times higher than that of EDM. At the same time, the roughing and finishing of the cavity and the machining of other parts of the mold can be completed in one clamping of the workpiece, which is the realization of the so-called "one-time" technology. In addition, this technology does not require electrodes and subsequent manual grinding and polishing, and it is easy to automate the processing process. Therefore, the application of high-speed processing technology has greatly increased the speed of mold development.
(3) Ability to process hard parts and thin-walled parts with complex shapes
According to the high-speed cutting mechanism, the cutting force is greatly reduced during high-speed milling, and the cutting process becomes easier. The lubrication of single-row tapered roller bearings is of great significance to the bearing. The lubricant in the bearing can not only reduce friction resistance, but also play a role in heat dissipation, reducing contact stress, absorbing vibration, and preventing corrosion. Tapered roller bearings rely on the rolling contact between the main parts to support the rotating parts. Different roller bearings can withstand different radial and axial forces. When choosing roller bearings, the choice should be made according to specific working conditions. High-speed cutting can process hardened steel with a material hardness of 60HRC or more without cutting fluid, which is the so-called hard cutting and dry cutting. What is more prominent is that the transverse cutting force is very small in high-speed milling, which is extremely beneficial for processing some thin ribs and thin walls in complex mold cavities. Of course, high-speed milling of molds also has certain limitations. When the hardness of the workpiece material is greater than 60HRC, and it has a narrow and deep cavity, and the chamfer and fillet are very small, high-speed milling is very difficult, and the organic combination of high-speed milling and EDM can achieve better Economic effect.