Programming processing of ordinary thread:
In the current CNC lathe, thread cutting generally has three machining methods: G32 direct cutting method, G92 direct cutting method and G76 oblique cutting method, because of the different cutting methods, programming methods are different, resulting in different machining errors. We should carefully analyze the operation and use, and strive to produce parts with high precision.
1, G32 direct cutting method, because both sides of the edge work at the same time, the cutting force is larger, and the row cutting is difficult, so in the cutting, the two cutting edges are easy to wear. When cutting the thread with larger pitch, because the cutting depth is larger, the blade wear is faster, resulting in the error of the thread diameter; But its processing precision is higher, so it is generally used for small pitch thread processing. Because its cutting tool moving cutting by programming to complete, so the processing program is longer; Because the blade is easy to wear, it is necessary to measure frequently in the processing.
2. G92 direct cutting method simplifies programming and improves efficiency compared with G32 instruction.
3, G76 oblique cutting method, because of the single edge processing, processing blade is easy to damage and wear, so that the processing thread surface is not straight, the knife sharp Angle changes, resulting in poor dental accuracy. However, because it is single-edge operation, the tool load is small, chip removal is easy, and the cutting depth is decreasing. Therefore, this machining method is generally suitable for large pitch thread machining.
Because this machining method is easy to remove chips, the blade machining condition is better, in the case of thread accuracy is not high, this machining method is more convenient. When the thread is processed with high precision, it can be finished with two knives. First, the rough turning is made by G76 machining method, and then the fine turning is made by G32 machining method. But we should pay attention to the starting point of the tool to be accurate, otherwise it is easy to mess up, resulting in scrap parts.
4, after the completion of the thread processing can be judged by observing the thread type of the thread quality to take timely measures, when the top of the thread is not pointed, increasing the amount of knife will make the thread large diameter increase, increase a large amount depending on the material plasticity, when the top of the tooth has been sharpened, increasing the amount of knife cut is proportional to the size of the decrease, according to this feature to treat the correct amount of thread cut, to prevent scrap.
