The thread milling method itself has certain natural advantages. Since the current thread milling cutter is made of cemented carbide, the processing line speed can reach 80-200m/min, and the processing speed of the high-speed steel taper is only 10~30m/min. Therefore, the thread milling cutter is suitable for high-speed cutting and processing thread. The surface finish is also greatly improved. Threading of high-hardness materials and high-temperature alloy materials, such as titanium alloys and nickel-based alloys, has always been a difficult problem, mainly because high-speed steel wire cones have a shorter tool life when machining the above-mentioned material threads, and use hard alloy thread milling. Knife-to-hard material threading is an ideal solution. The machinable hardness is HRC 58-62. For threading of superalloy materials, thread milling cutters also exhibit excellent processing performance and an unexpectedly long life. For threaded holes of the same pitch and different diameters, it takes a lot of tools to complete the tapping, but if you use a thread milling cutter, you can use a tool. After the tap wear and the thread size of the thread are less than the tolerance, it can not be used continuously, and can only be scrapped; when the thread milling cutter is worn and the threaded hole size is smaller than the tolerance, the necessary tool radius compensation adjustment can be performed by the numerical control system to continue. Threads of acceptable size are machined. Similarly, in order to obtain high-precision threaded holes, it is much easier to use a thread milling cutter to adjust the tool radius than to produce high-precision taps. For small-diameter threading, especially for threading of high-hardness materials and high-temperature materials, the taps sometimes break, block the threaded holes, and even scrap the parts; thread milling cutters, because the tool diameter is smaller than the machined hole, even if it is broken It does not block the threaded hole, it is very easy to take out, and it will not cause the parts to be scrapped. Compared with the tap, the cutting force of the tool is greatly reduced compared with the tap. This is especially important for large-diameter thread machining, which solves the problem that the machine load is too large. The problem of normal processing of the tap cannot be driven.
The machine-clamp blade thread milling cutter was introduced ten years ago. It is also recognized that the machining of threaded holes of M20 or more on the machining center can greatly reduce the processing cost by using a thread milling cutter compared with the tap. However, in recent years, the design and production technology of the whole solid carbide thread milling cutter has gradually matured, and a series of products with a complete range of sizes have been developed.
We have seen the development trend of thread milling cutters from the series of thread milling cutters developed by Israel VARGUS, a world-famous carbide thread cutter solution supplier, in recent years. The Millipro series covers M1.6×0.35 to M4; the Helicool series covers M5～M19; MITM multi-blade, high-efficiency machine-clamp thread milling cutter covers M19～M60 size range; Shell mill series multi-tooth installation, disc milling Thread milling cutters cover large diameter threading from M60 to M300 and even larger. To help users use thread milling solutions to make their application easier and more convenient, Vargas has also developed the TM Gen software system, which has been cultured to help users automatically select tools and automatically program the corresponding thread milling CNC. program.
For small-diameter threading applications, an aerospace company needs to machine 50 M1.6×0.35 threaded blind holes on an aluminum part. The problem encountered by the customer is: because it is a blind hole, it is difficult to remove the chips, and it is easy to break when using tap processing. Since tapping is the last process, such as scrapping parts, the large amount of processing time spent on the part will be lost. Finally, the customer chooses a thread milling cutter with M1.6×0.35 thread, the line speed Vc=25m/min, the speed S=4900r/min (machine limit), the feed per revolution fz=0.05mm/r, the actual machining time For 4 seconds/thread, all 50 workpieces were completed with one tool.
For a knife body manufacturer, the hardness of the cutter body is generally HRC44. For the small-diameter threaded hole of the compacting blade, it is difficult to process the high-speed steel wire cone, the tool life is short, and it is easy to break. For the M4×0.7 thread processing, the customer chooses Solid carbide thread milling cutter, Vc=60m/min, Fz=0.03mm/r, machining time 11 seconds/thread, tool life up to 832 threads, thread finish is very good.
For medium-diameter thread processing, there are three different sizes and the same pitch thread holes on the aluminum parts to be machined by a certain company. Previously, three taps were required to complete the machining. Now use thread milling cutter, cutting conditions: Vc = 100m / min, S = 8000r / min, fz = 0.04mm / r, processing a thread for 4 seconds, 3 seconds, 3 seconds, a tool can be processed 9000 threads, the tool has not been damaged after the entire batch has been machined.
In large-scale power generation, metallurgical equipment processing industry, pump and valve processing industry, thread milling cutter solves the problem of large-diameter thread processing and becomes an ideal machining tool with high efficiency and low cost. For example, a valve parts processing enterprise needs to process 2"×11BSP-30 thread, the material is cast steel, and hope to improve the processing efficiency. By using multiple chip flutes and multi-blade clip type thread milling cutter, adopt Vc=80m/ The cutting parameters of min, S=850r/min and fz=0.07mm/r realize the machining time of 2min/thread and the blade life is 620, which effectively improves the machining efficiency of large diameter thread.
As an advanced tool developed rapidly in recent years, thread milling cutter is more and more widely accepted by enterprises and exhibits excellent processing performance. It has become a powerful weapon for enterprises to reduce the cost of thread processing, improve efficiency and solve the problem of thread processing. .
As a method of machining thread by CNC machine tools, thread milling is first popular in Europe and America. With the development of CNC machine tools in China, it has gradually gained acceptance and love from customers in China. Thread milling is accomplished by means of the three-axis linkage function of the CNC machining center machine and the G02 or G03 helical interpolation command.