Thread milling methods and advantages of CNC machine tools

1. Thread milling, as a method of machining threads using CNC machine tools, first became popular in Europe and the United States. With the development of China’s CNC machine tools, it has gradually been accepted and loved by Chinese customers. Thread milling is to complete the thread milling work by means of the three-axis linkage function of the CNC machining center machine tool and the G02 or G03 spiral interpolation command.
Second, the advantages of thread milling processing methods.
1. Since the current manufacturing material of thread milling cutter is hard alloy, the processing linear speed can reach 80-200m/min, while the processing linear speed of high-speed steel wire cone is only 10-30m/min, so thread milling cutter is suitable for high-speed cutting. The surface finish of machined threads is also greatly improved. The thread machining of high-hardness materials and high-temperature alloy materials, such as titanium alloy and nickel-based alloys, has always been a relatively difficult problem, mainly because the tool life is short when high-speed steel wire tapers are used to process the threads of these materials, and carbide thread milling is used. Tool-to-hard material thread machining is an ideal solution. The machining hardness is HRC58-62. For thread processing of high-temperature alloy materials, thread milling cutters also show very excellent processing performance and a long life beyond expectations. For threaded holes with the same pitch and different diameters, multiple tools are needed to process the tapped holes, but if a thread milling cutter is used, one tool can be used. After the tap is worn and the thread size is smaller than the tolerance, it cannot be used and can only be scrapped; and when the thread milling cutter is worn and the thread hole size is smaller than the tolerance, the necessary tool radius compensation adjustment can be carried out through the CNC system, and then continue Process a thread of qualified size.
2. Similarly, in order to obtain high-precision threaded holes, it is much easier to use thread milling cutters to adjust the tool radius than to produce high-precision taps. For small-diameter thread processing, especially in the thread processing of high-hardness and high-temperature materials, the tap sometimes breaks, blocking the threaded hole, or even scrapping the part; using thread milling cutters, because the tool diameter is smaller than the processed hole, even if it is broken Will not block the threaded holes, it is very easy to take out, and will not cause the parts to be scrapped;
3. With thread milling, compared with taps, the cutting force of the tool is greatly reduced. This is particularly important for large-diameter thread processing, which solves the problem of too much load on the machine tool to drive the taps for normal processing. The machine-clamp blade type thread milling cutter came out ten years ago, and people have also realized that the use of thread milling cutters can greatly reduce the processing cost compared with the use of taps when processing threaded holes above M20 on the machining center.
4. In recent years, the design and production technology of solid carbide thread milling cutters have gradually matured, and a series of products with a complete range of sizes have been developed. We can see the development trend of thread milling cutters from the series of thread milling cutters developed by Israel VARGUS, a world-renowned supplier of carbide thread cutter solutions in recent years. Millipro series of cutters cover M1.6×0.35 to M4; Helicool series cover M5~M19; MITM multi-blade, high-efficiency machine clamp thread milling cutter series cover the size range of M19~M60; Shellmill series multi-tooth installation, disc milling The thread milling cutter covers the machining of large diameter threads from M60 to M300 and even larger sizes. In order to help users use thread milling solutions and make their application easier and more convenient, Vargos has also developed the TMGen software system, which has a Chinese culture, which can help users automatically select tools and automatically compile corresponding thread milling CNC programs . For small-diameter thread processing applications, an aerospace company needs to machine 50 M1.6×0.35 threaded blind holes on an aluminum part. The customer’s problem is: due to the blind holes, chip removal is difficult, and it is easy to break when using taps. ; Since tapping is the last process, if the part is scrapped, all the processing time spent on the part will be lost. Finally, the customer selects a thread milling cutter for processing M1.6×0.35 threads, linear speed Vc=25m/min, speed S=4900r/min (machine tool limit), feed per revolution fz=0.05mm/r, actual processing time For 4 seconds/thread, all 50 workpieces are completed with one tool.
5. For a cutter body manufacturer, since the cutter body hardness is generally HRC44, it is difficult to process the small diameter threaded hole of the compression blade with a high-speed steel wire taper, the tool life is short, and it is easy to break. For M4×0.7 thread processing, The customer chooses solid carbide thread milling cutter, Vc=60m/min, Fz=0.03mm/r, processing time 11 seconds per thread, tool life of 832 threads, and thread finish is very good.
6. For the processing of medium-diameter threads, there are three threaded holes of M12×0.5, M6×0.5, M7×0.5 in different sizes and the same pitch on the aluminum parts to be processed by an enterprise. Previously, three types of taps were required to complete Processing. Now use thread milling cutter, cutting conditions: Vc=100m/min, S=8000r/min, fz=0.04mm/r, the time for processing a thread is 4 seconds, 3 seconds, 3 seconds, one tool can be processed 9000 threads, after finishing the whole batch of parts processing, the tool is not damaged.
7. In the processing industries of large-scale power generation and metallurgical equipment, as well as the processing industries of pumps and valves, thread milling cutters have solved the problem of processing large-diameter threads and become ideal processing tools with high efficiency and low cost. For example, a valve parts processing enterprise needs to process 2″×11BSP-30 threads, the material is cast steel, and hopes to improve the processing efficiency. By selecting multiple chip flutes, multi-blade machine clamp thread milling cutters, Vc=80m/ With the cutting parameters of min, S=850r/min, fz=0.07mm/r, the machining time is 2min/thread and the blade life is 620 pieces, which effectively improves the machining efficiency of large-diameter threads.
8. As an advanced tool that has developed rapidly in recent years, thread milling cutters are becoming more and more widely accepted by enterprises, and they have shown excellent processing performance. They have become a key tool for enterprises to reduce thread processing costs, improve efficiency, and solve thread processing problems. A powerful weapon.