Thread whirl milling is a high-speed milling threading device or a dedicated high-efficiency threading machine for general lathes or Swiss lathes.
A thread-forming method for milling threads from a workpiece using a carbide forming knives mounted on a high-speed rotary cutter.
Due to its high milling speed (speed up to 400m/min), the machining efficiency is fast and compressed air is used for chip cooling.
The cutting is like a whirlwind during the machining process, hence get the name – whirl milling.
Whirl milling enables dry cutting, heavy-duty cutting, difficult-to-machine materials and ultra-high-speed cutting with low power consumption.
The surface roughness can reach Ra 0.8 μm.
The spindle speed of the machine tool is slow when the cyclone is milled, so the machine tool has high motion precision and good dynamic stability, and is an advanced thread processing method.
Whirl milling working principle
Whirl milling requires to finish the following five machining movements during the machining process:
- The cutter head drives the carbide forming knife to rotate at high speed (main motion)
- The machine tool spindle drives the workpiece to rotate slowly (assisted movement)
- Whirl milling moves along the workpiece axis according to the workpiece pitch or lead (feed motion)
- Whirl milling radial motion (cutting motion)
- Whirl milling has a degree of freedom in the adjustment of the helix angle within a certain range of angles. (rotary motion)
Whirl milling classification and application
The cutting form of whirl milling is divided into:
- Inner cutting
- Outter cutting
Whirl milling can be used to machine threads, bone screws, lead screws, worms, and screw parts etc.
Advantages of whirlwind milling threads
Compared to other general thread machining methods, whirl milling threads have the following advantages:
- High processing efficiency, which can be increased by more than 10 times compared with traditional processing efficiency;
- Due to the forming process, the product is formed by one knife, and the eccentric cutting does not need to retract the knife, and the precision is high;
- The whirl milling modified by the lathe does not change the structure of the lathe, the spiral angle is adjustable, and the installation is convenient; the cost of investing in special equipment is saved;
- The surface roughness can reach Ra0.8μm, the processing accuracy is improved by 2 level;
- The axial feed of the lathe is slow, easy to operate, and the professional skills of the workers can be reduced;