Technical for CNC lathe processing parts

What is lathe processing?
That is, on the lathe, the shape and size of the blank are changed by the rotary motion of the workpiece and the linear or curved motion of the tool, and processed to meet the requirements of the drawing parts.

Turning is a method of cutting the workpiece by using the rotation of the part relative to the tool on the lathe. The cutting function of turning is mainly provided by the workpiece rather than the tool. Turning is the most basic and common cutting method, and it occupies a very important position in production. Turning is suitable for machining revolving surfaces, and most workpieces with revolving surfaces can be processed by turning methods. Such as inner and outer cylindrical surface, inner and outer conical surface, end surface, groove, thread and rotary forming surface, etc., the tools used are mainly turning tools.

Among all kinds of metal cutting machine tools, lathes are the most widely used, accounting for about 50% of the total number of machine tools. The lathe can not only use turning tools to turn the workpiece, but also use drills, reamers, taps and knurling tools for drilling, reaming, tapping and knurling operations. According to different process characteristics, layout forms and structural characteristics, lathes can be divided into: Horizontal lathes, floor lathes, vertical lathes, turret lathes and profiling lathes, etc., most of which are horizontal lathes.

CNC lathe processing can process various types of materials. There are: 316, 304 stainless steel, carbon steel, tool steel, alloy steel, alloy aluminum, magnesium alloy, zinc alloy, titanium alloy, copper, iron, plastic, acrylic, POM, UHWM and other raw materials. It can process parts with complex structures.

Precautions for CNC lathe processing
The processing technology of CNC lathe is similar to that of ordinary lathe. However, because the CNC lathe is a one-time clamping, continuous and automatic processing to complete all turning processes. Therefore, the following aspects should be paid attention to:

1. Reasonable choice of cutting amount:
For high-efficiency metal cutting processing, the processed material, cutting tools, and cutting conditions are the three major elements. These determine the processing time, tool life and processing quality. The economical and effective machining method must be the reasonable choice of cutting conditions.
Three elements of cutting conditions: Cutting speed, feed rate and depth of cut directly cause tool damage. With the increase of cutting speed, the temperature of the tool tip will rise, which will cause mechanical, chemical and thermal wear. Cutting speed increased by 20%, tool life will be reduced by 1/2. The relationship between the feed condition and the wear on the back of the tool occurs in a very small range. However, the feed rate is large, the cutting temperature rises, and the tool wear is large. It has less influence on the tool than cutting speed. While the impact of the cutting depth of the tool is not as cutting speed and feed large. However, when cutting at a small depth of cut, the material being cut produces a hardened layer, which will also affect the life of the tool.

The user should choose the cutting speed to be used according to the processed material, hardness, cutting state, material type, feed rate, and depth of cut. The most suitable processing conditions are selected on the basis of these factors. Regular, stable wear and longevity are the ideal conditions. However, in actual operations, the choice of tool life is related to tool wear, dimensional changes to be processed, surface quality, cutting noise, and processing heat. When determining the processing conditions, it is necessary to conduct research according to the actual situation. For difficult-to-machine materials such as stainless steel, heat-resistant alloys, titanium alloys, and magnesium alloys, coolants or turning blades with good rigidity can be used.

2. Choose a tool reasonably:
(1) When rough turning, choose a tool with high strength and good durability to meet the requirements of large turning depth and large feed when rough turning.
(2) When finishing turning, choose tools with high precision and good durability. To ensure the requirements of machining accuracy.
(3) In order to reduce the time of tool change and facilitate tool setting, machine clamp tools and machine clamp turning blades should be used as much as possible.

3. Reasonable selection of fixtures:
(1) Try to use general fixtures to clamp the workpiece and avoid using special fixtures;
(2) The positioning datums of the parts coincide to reduce positioning errors.

4. Determine the processing route: The processing route is the movement track and direction of the tool relative to the part during the processing of the index-controlled machine tool.
(1) It should be able to guarantee the processing accuracy and surface roughness requirements;
(2) The processing route should be shortened as much as possible to reduce the tool idle travel time.