CNC Machining Parts:What are the Requirements for Precision CNC Machining Parts?

First of all, we must know what is a precision CNC machining part? It is actually a kind of machining, but it is more precise and requires higher production machinery and technology. With the development of industrialization, there are more and more classifications of CNC machining parts, more and more directions, and higher and higher CNC machining technology.

Therefore, the integration of precision CNC machining will become higher and higher in the future. It is no longer a simple CNC machining process. The combination of information technology and high-tech has played a better role, especially the digitization of CNC machining has made its development a qualitative leap, and it will become an important science in the development of the service industry in the future.

For precision CNC machining parts, the machining is very strict. There are specific requirements for size and accuracy, such as 1 mm plus or minus microns. If the size is too large, it will be scrapped. At this time, it is equivalent to remachining, which is time-consuming and laborious, and sometimes even the entire CNC machining material is scrapped. This has caused an increase in cost, and at the same time, these CNC machined parts are definitely unusable.

Precision CNC machining parts have strict requirements based on the size requirements, such as the diameter of the cylinder, and the positive and negative errors are within the specified requirements. There are also provisions for negative errors, such as online cylinders (take the simplest basic part as an example). If the diameter is too large and exceeds the error tolerance, it will not be inserted. If the actual diameter is too small, if it exceeds the lower limit of the allowable negative error, it will cause the insertion to be too loose and cause unsafe problems.

These are unqualified CNC machining parts, or the length of the cylinder is too long or too short, which exceeds the allowable error range. They are all unqualified CNC machined parts. They must be discarded or re-CNC processed. This will inevitably increase costs.

The requirement of precision CNC machining parts is actually the most important dimensional problem. Must be handled strictly in accordance with the attached drawings. As long as the CNC machining size is within the allowable error range, the actual CNC machining size will definitely not be exactly the same as the theoretical size of the drawing. Therefore, the requirements of precision CNC machining parts are strictly in accordance with the theoretical dimensions.

1. CNC machining principle error CNC machining error caused by approximate CNC machining motion or approximate tool contour. Because of the error in CNC machining principle, it is called CNC machining principle error. As long as the principle error is within the allowable range, this method is still feasible.

2. CNC machining machine tool geometric errors, manufacturing errors, installation errors, wear during use, etc. directly affect the CNC machining accuracy of the workpiece. Including the rotation of the spindle of the CNC machining machine tool, the linear motion of the machine tool guide rail and the error of the machine tool transmission chain.

3. Tool manufacturing errors, wear manufacturing errors, installation errors, wear, etc. in the CNC machining process will affect the CNC machining accuracy of the parts. During the cutting process, the cutting edge, cutting surface, parts and chips generate strong friction, which leads to tool wear. When the tool wear reaches a certain value, the surface roughness of the CNC machined parts increases, and the color and shape of the chips change, accompanied by vibration. Tool wear will directly affect cutting productivity, CNC machining quality and cost.

4. Fixture error CNC machining fixture error includes positioning error, clamping error, fixture installation error and tool setting error. These errors are mainly related to the accuracy of fixture manufacturing and assembly. The accuracy of CNC machining is not perfect. As long as the error is controlled within a certain range, it will not have much impact. Tool manufacturing error and wear.

5. Positioning error mainly includes reference error and positioner manufacturing error. When CNC machining parts on a machine tool, several geometric elements on the parts must be selected as the positioning reference for CNC machining. If you use the selected positioning datum and design datum (the datum is used to determine the surface size and position on the CNC machining part drawing). If misalignment occurs, a reference misalignment error will occur.

The positioning surface of the workpiece and the positioning element of the fixture together constitute a positioning pair. The positioning position is not accurate, and the large displacement of the CNC machined parts caused by the matching gap between the positioning pairs is called positioning. error. Inaccurate errors in positioning and CNC machining can only occur when the adjustment method is used, and will not occur during the trial cutting process.

6. Adjust the error. In each CNC machining process, the CNC machining system always adjusts in one way or another. Since the adjustment cannot be accurate, an adjustment error will occur. In the numerical control machining system, by adjusting the machine tool, cutting tool, fixture or workpiece, the mutual positioning accuracy of the numerical control machining part and the cutting tool on the machine tool is ensured. When the original accuracy of machine tools, tools, fixtures and CNC machining parts does not consider dynamic factors to meet the requirements of CNC machining, the adjustment error plays a decisive role in the CNC machining error.

7. The measurement error during or after the CNC machining parts is directly affected by the measurement method, gauge accuracy, CNC machining parts and subjective and objective factors.