Cutting step selection and principle of shaft parts
After the parts and the turning tool are clamped, the cutting amount has been roughly selected. The next step is to turn. From which end does the drawing start turning? This is a very important job. You may have the parts and turning tools installed correctly, and the cutting amount is also good. However, if the turning step is not good, the waste will also be produced.
In order to select the turning steps of the shaft parts correctly, first understand the selection principle.
1. Parts can be used according to different quantity and precision requirements, machine tool conditions, two different machining principles can be used: process concentration and process dispersion principle.
Process concentration = After the first part is fully loaded, the second and third are...
Process dispersion = first the same surface of all parts, then the second, third ...surface of all parts.
Generally speaking, when the batch size of the parts is small, or only a few of the intermediate surfaces have higher positional accuracy requirements, and the precision of the lathe is higher, the concentration principle can also be adopted. On the contrary, the principle of process dispersion is adopted.
2. When turning parts: Generally, it is divided into three stages: roughing, semi-roughing and finishing.
3. For parts with high precision requirements, in order to eliminate internal stress, after roughing, it must be quenched and tempered. (by 1.5-2.5 mm margin)
4. If the parts are turned after grinding, rough turning, and no longer fine. There is a proper margin after roughing.
5. When turning the step shaft: Generally, it is the larger end of the turning diameter. This ensures the rigidity of the shaft during turning.
6. When grooving on the shaft, it is usually after roughing and semi-finishing, before finishing the car. If the part is steel, the precision is not high, and it can also be done after finishing the car. This depth is easy to control.
7. The thread on the shaft is usually turned after the semi-finished turning. If the shaft is not very rigid, the thread can also be placed in the final turning.