Technology and tooling of CNC turning

Technology and tooling of CNC Turning

The processing technology of CNC lathes is similar to that of ordinary lathes, but since CNC lathes are clamped once, all automatic turning processes are completed automatically, so the following aspects should be noted.

1. Reasonable choice of cutting amount

For high-efficiency metal cutting, the material to be processed, cutting tools, and cutting conditions are the three major elements. These determine the processing time, tool life and processing quality. The cost-effective processing method must be a reasonable choice of cutting conditions.
Three elements of cutting conditions: cutting speed, feed rate and cutting depth directly cause tool damage. As the cutting speed increases, the tool tip temperature will rise, and mechanical, chemical, and thermal wear will occur. Cutting speed increased by 20%, tool life will be reduced by 1/2.

The relationship between the feed conditions and the wear on the back of the tool occurs within a very small range. However, the feed rate is large, the cutting temperature rises, and the rear wear is large. It has less influence on the tool than the cutting speed. Although the depth of cut has no effect on the cutting tool and the feed rate is large, when cutting at a small depth of cut, the hardened layer of the material being cut will also affect the life of the tool.
The user should select the cutting speed to be used according to the processed material, hardness, cutting status, material type, feed amount, cutting depth, etc.

The selection of the most suitable processing conditions is selected on the basis of these factors. Regular and stable wear and tear to reach the life is the ideal condition.
However, in actual operations, the choice of tool life is related to tool wear, dimensional changes to be processed, surface quality, cutting noise, processing heat, etc. When determining the processing conditions, it is necessary to study according to the actual situation. For hard-to-machine materials such as stainless steel and heat-resistant alloys, coolant or rigid blades can be used.

2. Reasonable selection of tools (1) When rough turning, choose a tool with high strength and good durability, so as to meet the requirements of large back eating amount and large feed during rough turning.
(2) When finishing, choose a tool with high accuracy and good durability to ensure the accuracy of processing.
(3) In order to reduce the tool change time and facilitate tool setting, the machine clamp knife and machine clamp blade should be used as much as possible.

3. Reasonable choice of fixtures (1) Try to use general fixtures to clamp the workpiece, avoid using special fixtures;
(2) The positioning benchmarks of the parts overlap to reduce positioning errors.

4. Determine the processing route

The processing route is the movement path 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 empty travel time.

5. The relationship between processing route and processing allowance

At present, under the condition that the CNC lathes have not yet reached the universal use, the excess balance on the blanks, especially those containing forged and cast hard skin layers, should be arranged on ordinary lathes for processing. If you must use a CNC lathe for processing, you need to pay attention to the flexible arrangement of the program.
6. The main point of the fixture installation is that the connection between the hydraulic chuck and the hydraulic clamping cylinder is realized by the * tie rod. The main points of the hydraulic chuck clamping are as follows: first, remove the nut on the hydraulic cylinder with the carrying hand, remove the pull tube, and remove Pull out, and then remove the chuck fixing screw with a hand to remove the chuck.