What are the characteristics of CNC turning process?

Turning is one of the most basic and most commonly used cutting methods. For most workpieces with revolving surfaces, it can be processed by turning, such as inner and outer cylindrical surfaces, inner and outer tapered surfaces, end surfaces, grooves, threads, and rotary forming surfaces. Ordinary lathes include horizontal lathes, floor lathes, vertical lathes, turret lathes and profiling lathes, among which horizontal lathes are the main ones.

With the development of modern technology, there are more and more high-strength and high-hardness engineering materials. Traditional turning technology has been unable to meet or realize the processing requirements of certain high-strength and high-hardness materials, while modern hard turning technology Make it possible and obtain significant benefits in production.

1. Introduction to the characteristics of turning

(1) High turning efficiency.Turning efficiency is higher than grinding. Turning uses a large cutting depth and high workpiece speed, and its removal rate is usually several times that of grinding. The lathe can complete the processing of various surfaces in one clamping process, while the grinding requires multiple installations, so the auxiliary time for processing is short, and the position accuracy of each processing surface is high.

(2) The cost of equipment investment is low. Under the same productivity, the investment of a lathe is obviously better than that of a grinder, and the cost of its auxiliary system is also low. In small batch production, turning does not require special equipment, while the processing of large quantities of high-precision parts requires CNC machine tools with high rigidity, positioning accuracy and repeat positioning accuracy.

(3) The lathe suitable for small batch flexible production is a flexible processing method with a wide range of processing. The lathe is easy to operate and the turning fixture is fast. Compared with grinding, hard turning is more suitable for the requirements of flexible production.

(4) Hard turning can obtain better overall machining accuracy.The machined surface is of good quality and the machined roundness is accurate. It can ensure a high position accuracy on the machined surface. There will be no burns and cracks during the cutting process. Most of the heat generated during the machining process is taken away by the cutting oil.

2. Turning tool materials and their selection.

(1) Coated carbide tools.

Coated cemented carbide tools is to coat one or more layers of coatings with good wear resistance on the toughened cemented carbide tools. The coating usually has the following two functions: On the one hand, the thermal conductivity of the coating is far It is lower than the tool matrix and workpiece material, thereby weakening the thermal effect of the tool matrix; on the other hand, it can effectively improve the cutting friction and adhesion, and reduce the generation of cutting heat.

(2) Ceramic tool

It has the characteristics of high hardness, high strength, abrasion resistance, good chemical stability, good adhesion resistance, low friction coefficient and low price. In normal use, the durability is extremely high, and the speed is several times higher than that of cemented carbide. It is especially suitable for the processing, finishing and high-speed processing of high-hardness materials.

(3) Cubic boron nitride tool

The hardness and wear resistance of cubic boron nitride is second only to diamond, and it has excellent high temperature hardness. Compared with ceramic tools, its heat resistance and chemical stability are slightly worse, but its impact strength and crush resistance are better. It is widely used Compared with carbide tools, the cutting speed of hardened steel, pearlite gray cast iron, chilled cast iron, high temperature alloy, etc. can be increased by orders of magnitude.