How to divide nc machine tool processing process and processing route

　　In the CNC machine tool, especially in the machining center processing parts, the process is very complex, many parts only need to be installed in a card can complete the whole process. But the rough processing of parts, especially the processing of the datum and positioning surface of the blank parts of the forging, should be completed on the ordinary machine tool, and then be processed on the CNC machine tool. This can play the characteristics of CNC machine tools, maintain the accuracy of CNC machine tools, prolong the service life of CNC machine tools, reduce the cost of CNC machine tools. After rough machining or semi-finishing parts are inserted into the CNC machine tool, the CNC machine tool carries out semi-finishing and finishing step by step in accordance with the specified process.

　　Selection of workpiece for machining

　　Different types of parts should be processed on different types of CNC machine tools. CNC lathes are suitable for complex shaft parts and mold cavity formed by complex curve rotation. CNC vertical boring and milling machine and vertical machining center for processing box, box cover, plane CAM, sample, complex shape plane or three-dimensional parts, as well as mold inside and outside the cavity. CNC horizontal boring and milling machine and horizontal machining center for processing all kinds of complicated curves, surfaces, impeller, mold, etc. In short, different types of parts to choose different CNC machine tools for processing.

　　1, in the NUMERICAL control machine tool processing parts of the process division method:

　　(1) The tool concentration sequencing method is divided by the tool process, with the same knife to complete all parts can be completed. Then use the second knife and the third knife to finish where they can finish. This can reduce the number of tool changes, compression of air travel time, reduce unnecessary positioning errors.

　　(2) rough, finishing sorting method for a single part to rough processing, semi-finishing, and then finishing. For a batch of parts, first all rough machining, semi-finishing, and then finishing. Between coarse and finishing processing, an interval of time, in order to make the deformation of parts after rough processing is fully restored, and then finishing, in order to improve the machining accuracy of parts.

　　(3) according to the processing parts of the order method, the first processing plane, positioning surface, after the processing hole; Process simple geometric shapes first, and then process complex geometric shapes; Machining the parts with lower accuracy first, and then machining the parts with higher accuracy requirements.

　　In short, in the CNC machine tool processing parts, the division of the processing process according to the specific situation of the parts of the specific analysis. Many processes are arranged in an integrated manner according to the above sequential method.

　　2, the workpiece card loading method

　　In the CNC machine tool processing parts, because the process is concentrated, often is in a card to complete the whole process. Therefore, the positioning and clamping methods of parts should be fully paid attention to the following problems:

　　① Try to use combined fixture. When the bulk of the workpiece is large and the workpiece precision is higher, special fixture can be designed.

　　(2) Parts positioning, clamping parts should be considered not to interfere with the parts of the processing, tool replacement and important parts of the measurement, especially to pay attention to the occurrence of tool and workpiece, tool and fixture collision phenomenon.

　　(3) the clamping force should strive to pass (or close to) the main support point or in the triangle formed by the support point; Should strive to close to the cutting part, and in a good place of rigidity. Try not to be processed above the aperture, to reduce parts deformation.

　　(4) parts of the card, positioning to take into account the consistency of repeated installation, to reduce the knife time, improve the consistency of the processing of the same batch of parts. Generally, the same batch of parts adopt the same positioning datum and the same clamping method.

　　3, the determination of processing route

　　Machining path is the path and direction of tool motion in the process of exponential control machine tool. It is very important to determine the machining route of each process, because it affects the machining accuracy and surface roughness of parts. The determination of the processing route should consider the following points:

　　① Try to reduce the time of cutting in and out and other auxiliary time.

　　(2) When milling the contour of parts, we should try to use the smooth milling processing mode to reduce the vibration of machine tools and improve the surface roughness and machining accuracy of parts.

　　(3) Choose reasonable position of cutting and cutting back, and try to avoid stopping in the middle of normal cutting and feeding along the contour of parts. The position of the forward and backward knife should be selected in the unimportant position.

　　(4) The processing route is generally processed outside the contour, and then processed inside the contour.