Thread milling cutter numerical control technology

966Hits2014-04-17 08:26:58　Source:korloy

With the popularity of CNC machine tools, thread milling technology application in mechanical manufacturing industry more and more.Thread milling is through the three axes linkage numerical control machine tool, use thread milling cutter for milling spiral interpolation and form thread, cutting tool in the horizontal plane circular motion for one week, each term in a vertical plane linear movement a pitch.Thread milling processing with high efficiency, high quality and good cutting tool good commonality, the processing safety, and many other advantages.Currently used many, many different kinds of thread milling cutter, the paper from the application characteristics, tool structure, processing technology, such as make some analysis of several common thread milling cutter is introduced.

1 Common clip-on thread cutter

Machine clamp type thread cutter is commonly used in the thread milling and cheap tool, its structure is similar to PuTongJi clamp cutter, the reusable of tool holder and easy to replace the blade.For processing taper thread, also can use a special tool rod machining taper thread and blade, this with multiple thread cutting teeth on the blade, cutting tool along the spiral machining can be a week out of the multiple thread tooth, such as with a five 2 mm thread cutting gear milling cutter, along the spiral machining can be a week out of the five thread depth of thread of 10 mm.In order to further improve the efficiency of processing, can choose machine clamp type thread cutter blade.By increasing the number of cutting edges, can significantly improve the feed rate, but the distribution on the circumference of each blade between the radial and axial positioning error will affect the thread machining accuracy.Such as for multipoint machine thread milling cutter machining precision is not satisfied, can also try to only a blade for processing.When choosing machine clamp type thread cutter, should be processed according to the factors such as the diameter of the thread, depth and workpiece material, as far as possible with larger diameter cutter bar (rigid) in order to improve the cutting tool and the appropriate blade material.Machine clamp type thread cutter's machining depth is determined by the effective of the cutting depth.Due to the blade length less than the effective cutting depth of tool holder, so when processing thread depth is greater than the length of the blade need stratification for processing.

2 Common integral thread milling cutter

Integral thread milling cutters are made of solid carbide materials, some are adopted coating.Integral thread cutter with compact structure, is suitable for machining medium and small diameter of screw thread;There are also the integral thread milling cutter used for machining taper thread.Such cutting tools with good rigidity, especially the integral thread milling cutters with spiral slot, when processing high hardness materials can effectively reduce the cutting load, improve processing efficiency.Integral thread cutter tooth on the cutting edge is full thread, along the spiral machining a week can complete the whole thread, without layered like machine clamp type cutter machining, so the machining efficiency is higher, but the price is relatively expensive.

3 integral thread milling cutter with chamfering function

With the function of chamfering of the structure of the whole thread cutter is similar to common whole thread cutter, but in the cutting edge of the roots (or end) has dedicated chamfering edge, but at the same time of processing thread processing thread end chamfering.Machining chamfering has three ways, when the cutter diameter is large enough, can be directly used chamfering edge economic Angle of comparison, this method is limited to machining internal thread orifice chamfering.When the cutter diameter is small, can use chamfer edge machining chamfering by circular motion.But in the use of cutting blade root ministry chamfer edge chamfering processing, pay attention to the cutting tool thread cutting section and should have a certain gap between, to avoid interference phenomenon.Such as processing thread depth is less than the effective length of cutting, cutting tool, cutting tool will not be able to achieve the function chamfering, therefore when selecting cutting tools shall guarantee that the cutting length and the effective depth of thread match each other.

4 Thread drill milling cutter

Thread made from solid carbide drill milling cutters, is a kind of medium and small diameter internal thread efficient tool.Screw drill milling cutter can be a complete drill tap, orifice chamfering and the internal thread processing, reduced the number of tool use.But this defect is poor universality of cutting tool, the price is more expensive.The tool by the head of the drilling parts, in the middle of the thread milling and cutting chamfer edges of blade root of three parts.Drilling section diameter is the bottom diameter cutter can processing thread.Restricted by drilling section diameter, a screw drill milling cutter can only process one kind of specifications of the internal thread.When choosing screw drill milling cutter, not only should consider to be processing thread hole size, should also pay attention to the effective processing cutting tool length and the matching of the depth of the hole processed, otherwise cannot achieve chamfering function.

5 Thread screw drill milling cutter

Spiral drill milling cutter is also a kind of thread used for internal thread efficient processing of solid carbide cutting tools, can also processing out of the bottom hole and the thread at a time.The tool end like vertical milling cutter cutting edges.The screw helix Angle is not big, so tools for helical motion processing thread, end cutting edge removal of workpiece material processing out of the bottom hole first, then by cutting tool at the back of the processing thread.Some threaded screw drill milling cutter with a chamfer edge, can process the orifice chamfering at the same time.The cutting tool machining efficiency is very high, and versatility is better than screw drill milling cutter, the cutting tool machining internal thread diameter in the range of D ~ 2 D for the blade diameter (D).

6 Milling thread cutting tools

Milling depth of thread cutting tool is a single tooth cutter.Common thread have multiple thread teeth on the cutter blade, cutting tool and the workpiece contact area is large, the cutting force is large, and the internal thread machining cutter diameter of thread must be smaller than the aperture.Because of the influence of blade diameter is restricted, the cutting tool rigidity, and thread milling cutters for unilateral force, thread milling deep easy appear to knife phenomenon, affecting thread machining precision, so the general thread cutter effective cutting depth of about 2 times the diameter of the blade.While using single tooth deep thread milling cutter can better overcome the above shortcomings.Due to reduced the cutting force, can significantly improve the thread processing depth, cutter effective cutting depth can be up to 3 ~ 4 times the diameter of the blade.

7 Thread milling cutting tool system

Versatility and efficiency is a prominent contradiction of thread milling cutters, some of which has the function of composite cutting tools (such as screw drill milling cutter) but poor generality, high grinding efficiency and general efficiency good tool is not high.To solve this problem, a lot of cutting tool manufacturers developed a modular system thread milling tools.The cutting tool system generally consists of the handle, dimpling chamfering and general thread cutter blade, can choose according to processing requirements of different types of dimpling chamfering edge and screw thread milling cutter.The cutting tool system generality, and high machining efficiency, but the tooling cost is higher.
Briefly introduces several commonly used above the functions and features of thread milling tools.When milling thread, cooling is also vital, recommend the use of machine tools and cutting tools with inner cooling functions.Because in cutting tools high speed rotates, centrifugal force under the action of the external coolant is not easy to enter.Internal cooling way besides can be a good tool for cooling, what is more important in the blind hole thread machining high pressure coolant helps chip removal, especially when processing small diameter of inside thread hole need high pressure cooling, to ensure smooth chip removal.In addition, still should consider when choosing thread milling tools specific processing requirements, such as the production batch number, screw hole, workpiece materials, thread accuracy, size, and many other factors, the reasonable selection tool.