A Brief Discussion on Precautions for CNC Lathe Processing Technology
1. Reasonably choose cutting parameters
For efficient metal cutting, the material being machined, cutting tools, and cutting conditions are the three major elements. These determine the processing time, tool life, and processing quality. The economically effective processing method must be a reasonable choice of cutting conditions.
The three elements of cutting conditions: cutting speed, feed rate, and cutting depth directly cause tool damage. With the increase of cutting speed, the temperature of the cutting edge will rise, resulting in mechanical, chemical, and thermal wear. Increasing cutting speed by 20% will reduce tool life by half.
The relationship between feed conditions and tool wear occurs within a very small range. But with a large feed rate, the cutting temperature rises, and there is significant wear later on. It has less impact on the cutting tool than the cutting speed. Although the impact of cutting depth on cutting tools is not as significant as cutting speed and feed rate, in micro depth cutting, the material being cut produces a hardened layer, which also affects the tool's lifespan.
Users need to choose the cutting speed based on the material being processed, hardness, cutting state, material type, feed rate, cutting depth, etc. As shown in the table below:
The selection of suitable processing conditions is based on these factors. Regular and stable wear and tear to achieve lifespan is the ideal condition.
However, in practical operations, the choice of tool life is related to tool wear, changes in machined dimensions, surface quality, cutting noise, machining heat, and other factors. When determining the processing conditions, it is necessary to conduct research based on the actual situation. For difficult to machine materials such as stainless steel and heat-resistant alloys, coolants or blades with good rigidity can be used.
2. Reasonably choose cutting tools
1) When rough cutting, it is necessary to choose cutting tools with high strength and good durability to meet the requirements of large back cutting and large feed rate during rough cutting.
2) When precision machining, it is necessary to choose tools with high precision and good durability to ensure the required machining accuracy.
3) To reduce tool changing time and facilitate tool alignment, machine clamped knives and machine clamped blades should be used as much as possible.
3. Reasonably choose fixtures
1) Try to use universal fixtures to clamp workpieces and avoid using specialized fixtures;
2) Align the positioning benchmarks of the parts to reduce positioning errors.
4. Determine the processing route
The machining route refers to the motion trajectory and direction of the tool relative to the part during the CNC lathe machining process.
1) Should be able to ensure machining accuracy and surface roughness requirements;
2) Efforts should be made to shorten the machining route and reduce the tool idle time.
5. The relationship between machining route and machining allowance
At present, in the absence of widespread use of CNC lathes, excessive allowance on the blank, especially the allowance containing forged or cast hard skin layers, should generally be arranged for processing on ordinary lathes. When using a CNC lathe for machining, attention should be paid to the flexible arrangement of the program.
6. Key points for fixture installation
At present, the connection between the hydraulic chuck and the hydraulic clamping cylinder is achieved by a pull rod, as shown in Figure 1. The key points for clamping the hydraulic chuck are as follows: first, use a handle to remove the nut on the hydraulic cylinder, remove the pull tube, and extract it from the rear end of the spindle. Then, use a handle to remove the chuck fixing screw to remove the chuck.
The smoothing edge on a cutting tool refers to a small section of the blade that is ground parallel to the tip of the tool in the direction of the secondary angle behind the cutting edge. It is mainly used for a second cutting after the cutting edge is cut, which is equivalent to removing burrs and other scars during the precision machining process. The purpose is to improve the surface roughness of the workpiece and is commonly used on precision machining tools.
The process of CNC lathe machining is similar to that of ordinary lathes, but due to the fact that CNC lathes are one-time clamping and continuous automatic machining completes all turning processes, the following aspects should be noted.
1. Reasonably choose cutting parameters
For efficient metal cutting, the material being machined, cutting tools, and cutting conditions are the three major elements. These determine the processing time, tool life, and processing quality. The economically effective processing method must be a reasonable choice of cutting conditions.
The three elements of cutting conditions: cutting speed, feed rate, and cutting depth directly cause tool damage. With the increase of cutting speed, the temperature of the cutting edge will rise, resulting in mechanical, chemical, and thermal wear. Increasing cutting speed by 20% will reduce tool life by half.
The relationship between feed conditions and tool wear occurs within a very small range. But with a large feed rate, the cutting temperature rises, and there is significant wear later on. It has less impact on the cutting tool than the cutting speed. Although the impact of cutting depth on cutting tools is not as significant as cutting speed and feed rate, in micro depth cutting, the material being cut produces a layer, which also affects the tool's lifespan.
Users need to choose the cutting speed based on the material being processed, hardness, cutting state, material type, feed rate, cutting depth, etc. As shown in the table below:
The selection of suitable processing conditions is based on these factors. Regular and stable wear and tear to achieve lifespan is the ideal condition.
