CNC lathe turning trapezoidal thread
Turning trapezoidal thread and the method of turning the triangle thread is generally similar, but because of the darker teeth, CNC lathe factory thread cutting tool radial cutting force larger, so the greater turning pitch trapezoidal thread t more use of roughing knife And finishing tools were roughing and finishing.
Trapezoidal thread with low-speed cutting and high-speed cutting two ways.
(1) low-speed cutting trapezoidal thread trapezoidal thread on the accuracy of the higher requirements, and in the repair or single-piece production, often using low-speed cutting method.
When cutting thread trapezoidal thread less than 4mm, the general can only use a turning tool, the use of straight-forward method and a small amount of left and right feed, and then finishing the turning tool in the roughing after finishing.
When the turning thread larger trapezoidal thread, in order to avoid the three cutting edges while involved in cutting and vibration, should be rough with the turning tool, using the left and right way to feed the knife way to rent a car. CNC lathe plant to ensure the height of the tooth, and then use the fine-turning tool straight finishing method for precision forming; when the pitch is great, then with a radial rake angle of zero, , Using the method of getting around the knife fine trapezoidal thread.
(2) High-speed cutting trapezoidal thread Turning rigidity, precision less demanding trapezoidal thread, carbide thread turning tools can be used for high-speed cutting.
When cutting with this type of turning tool, it is unsafe to operate because the three cutting edges are involved in the cutting at the same time and the ribbon-shaped chips will flow out.
To this end, CNC lathe factory can be used thread lathe. This thread turning tool in the front of the two symmetrical arc grinding, so that the radial rake angle y. Increase. CNC lathe two arc also rake face was 3. ~ 5. Roof structure.
This type of turning tool reduces the cutting force and increases the strength of turning tools, thereby reducing the cutting vibration. CNC lathe at the same time the formation of spherical chip, so that chip-free smooth.
(3) turning trapezoidal thread operation points
1) Calculate the width of the socket, that is, trapezoidal thread turning tool tip width. According to Table 7-5w = 0.366P-0.536a thread roughing tool nose width should be less than a, to the fine car left a margin.
2) Calculate the height of the tooth type, that is, the amount of back teeth to eat the tooth ^, according to Table 7-5 ^ = 0. 5P 十 Ⅱ Under normal circumstances, in the roughing, which should reach the desired amount of back to eat knife to ensure that the thread Trail size, finishing, only fine car teeth on both sides.
3) When trapezoidal thread finishing, the turning tool must always be sharp, the cutting speed% (5 m / min, and sufficient cutting fluid.)
4) 茌 low-speed finishing thread, the best use of flexible Arbor, to prevent cutting vibration or Zabao phenomenon.
5) CNC lathe factory trapezoidal thread commonly used copper alloy and cast iron and other brittle metals, relatively easy processing. CNC lathe trapezoidal thread lathe cutter bar should be limited diameter conditions, try to increase the cross-section and shorten the length of the general selection of integral high-speed steel, in order to improve the strength and rigidity of the turning tool.
6) After the trapezoidal thread car is good, use a fine file or grinding stone trim to remove the sharp corners or burrs on the thread form.