What are the common and efficient CNC thread machining methods? Thread machining is one of the important applications of CNC machining center. The machining quality and efficiency of thread will directly affect the machining quality of parts and the manufacturing efficiency of machining center. With the increasing function of CNC machining center and the improvement of cutting tools, the way of thread machining is constantly improving, and the accuracy and efficiency of thread machining are gradually increasing. In order to enable the process staff to correctly select the thread processing mode, improve the production efficiency, and prevent quality events in the processing, several commonly used thread processing modes in CNC machining centers are summarized as follows:
In NC machining, the commonly used processing methods of thread can be divided into: NC turning, NC milling, tapping and whirlwind milling.
1、 CNC lathe
It is advisable to turn metric, inch, modulus and diameter control four kinds of standard threads on CNC lathe. No matter which thread is turned, there must be a strict activity relationship between lathe spindle and cutter: that is, every revolution of spindle (i.e. one revolution of workpiece), the cutter should move an average interval of lead. If the thread is processed on the CNC lathe, it can be described as follows with a diagram
If it is to be subdivided, it can also be divided into: direct feed of radial feed; control turning method of flow feed; oblique feed method of lateral feed.
Straight forward method: applicable to small pitch, with lead less than 3mm, G32 or G92
Oblique approach: it is not easy to tie the knife, it is preferred to use G76 command without undercut
Control turning method: large profile, large pitch, lead greater than 5mm, macro program
2、 CNC milling
Thread milling, in the thread milling machine with disc milling cutter or comb milling cutter for milling. Disc milling cutter is mainly used for milling trapezoidal external thread of screw rod, worm and other workpieces. The comb milling cutter is used for milling internal and external common thread and taper thread. The length of the working part of the multi edge milling cutter is longer than the length of the thread to be processed. Therefore, the workpiece only needs to rotate 1.25 ~ 1.5 to be processed, with a high production rate. The pitch accuracy of thread milling can reach 8-9 grades, and the surface roughness is r5-0.63 μ M. This method can be used for mass production of common precision screw thread or rough machining before grinding. After the spiral slope milling of the turning tool, the screw thread is generated, which is not as ordinary as the lathe, but also has high efficiency when it is used in a unique scene.
Tapping is to use a certain torque to screw the tap into the bottom hole pre drilled on the workpiece to process the internal thread.
Threading is to cut the external thread on the bar (or tube) workpiece with a die. The machining accuracy of tapping or threading depends on the accuracy of tap or die. Although there are many ways to process internal and external threads, small-diameter internal threads can only be processed by taps. Tapping and threading can be operated by hand, or by lathe, drilling machine, tapping machine and threading machine.
4、 Whirlwind milling
CNC whirlwind milling is installed on CNC lathes and other lathes by Zhonghua broad users, which makes the processing efficiency of single head multi head, worm, screw, nut and other threaded products increase by 10-30 times, the processing accuracy increases by two poles, and the brightness reaches 0. 8um. There is no difference between the whirlwind milling and the numerical milling in the processing technology. If the blade is installed in the cutting cutter head and rotates around the cylindrical part, the thread can be cut out in one-time cutting, with high efficiency!
Focus on the operation of screws, worm and other unique scenes!
Only by accurately selecting thread processing methods and cutting tools can we effectively improve the efficiency and quality of thread processing, increase the application efficiency of CNC machining center, and reduce the processing cost. Every NC processing staff should be skilled in charge.
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