Common problems and solutions of nc machining
CNC machine tools can be logically processed with a control code or other symbols of the instructions specified by the program to control the movement of machine tools, according to the shape and size requirements of the drawings, automatically make parts, so as to achieve a high degree of automation and compound centralized machine tools. The emergence of numerical control machine tools has solved the problem of complex, precise, small batch and multi-variety parts processing. But in the process of easy to appear tool wear, machining allowance is too large and so on. The following is a brief introduction of common problems and solutions of CNC machine tool processing:
1. processing flat, not only
In the CNC machine parts processing, finishing is an important process for the surface, but also often to do the process, the surface quality requirements are higher. But in the actual processing, sometimes will get uneven and not only plane, do not meet the requirements.
The main reason for this problem is that in the finishing process, the feed speed is too fast, and the vibration caused by the rapid movement of the tool is easy to leave uneven path to the machining surface. In addition, there is a problem in the opposite finishing, sometimes there will be a certain difference between the two adjacent tool path tool marks, is the direction of the cutting tool is not consistent, to avoid this problem, should use the full shun milling processing.
2. the finishing side of the knife mark is too obvious
In the workpiece processing of CNC machine tools, almost every workpiece will require fine milling side, and a lot of time will appear fine milling side of the knife mark is too obvious problem, this is absolutely not allowed to appear, will seriously affect the appearance of the workpiece.
The main cause of this problem is the improper selection of advance and retreat position and parameters, as well as the cutting in depth stratification. There are many kinds of machining software, and different machining software provides the milling method will also have differences, but will provide the depth selection of the under knife and in and out of the knife parameter selection. In order to avoid the above problems, we can make relevant adjustments in three aspects. The first is the selection of the feed point to be correct, should be selected in the most edge, not in the middle of the place, the point can no longer be the same side; The second is if must again in the middle of the knife, in advance and retreat of the knife, increase an overlap; The 3rd it is when undertaking flank finishing, had better use whole cut deep processing.
3. precision milling tool marks
In the ordinary processing and high-speed processing, need to carry out tool replacement, and if in the process of changing the knife operation do not pay attention to the parameters of the relevant adjustment, there will be obvious traces, serious impact on the appearance of the workpiece.
In the bottom or side of the fine milling, knife mark is a common phenomenon, many times people will think that this is unavoidable error, in fact, this is completely avoidable.In the processing of the workpiece, the precision machining of the concave corner needs to be replaced with a small tool, because the force in the processing process and swing, it will be in the corner is very easy to produce the trace of the knife.
4. after finishing surface or side to leave burr or batch front
Modern workpiece processing for the surface requirements are increasingly high, for the emergence of burr or batch edge is not acceptable, and if the file to correct the workpiece will affect the accuracy of the workpiece and size, etc. But in the actual production, there will still be a lot of burr and batch front.
And to solve this problem, the use of the tool must be very careful to use a special tool, to ensure sharp cutting. In addition, also want to do a good job in the planning of the knife road, increase the second finishing knife road, is the first processing surface, and then processing the side, and then processing the surface, so you can ensure that there is no burr and batch front, can not be polished workpiece is very useful.
5. for the special shape of the workpiece finishing
For some workpieces of special shape, the software usually has fitting error, sometimes if the error of calculation is too large, it will cause the deformation of the workpiece, affecting the appearance. To solve this problem, it is necessary to start from the software, the error of a reasonable control, neither affect the speed of calculation, nor cause deformation of the workpiece.
6. Serious tool wear causes errors
Tool precision directly affects the quality of the workpiece, and in the process of machining tool wear too fast will cause the deviation of the workpiece size. The causes of rapid tool wear include its own material, workpiece material, cutting process parameters, cutting oil properties and so on.
