In the machining center, the machining of CNC lathe generally requires the use of multiple cutters, so we need to reasonably organize the machining sequence, which is conducive to improving the machining accuracy, machining efficiency and economic benefits. When organizing the machining sequence of CNC lathe, the general process rules of "base surface first", "surface first hole second", "primary first second" and "coarse first precision" shall be followed.
The selection of positioning datum directly affects the organization of processing sequence. The surface used as positioning datum should be processed first, so as to provide a reliable positioning datum for processing other surfaces. Because the surface processed after selecting the positioning datum of this process may be the positioning datum of the next process, after the positioning datum of each processing process is determined, the general sequence of the whole process can be deduced step by step from the final finishing process.
When determining the machining sequence of CNC lathe, it is necessary to determine whether the parts should be pre processed before machining. Pre machining is often done by general machine tools. If the accuracy of the blank is high, the positioning is reliable, or the machining allowance is sufficient and even, the pre machining can be avoided, and the machining can be carried out directly on the machining center. At this time, the process differentiation of the machining center should be considered according to the accuracy of the rough benchmark, so one process or several processes can be divided to complete.
When machining parts with CNC lathe, the most difficult thing to ensure is the scale between the machining surface and the non machining surface, which is the same as that of CNC milling. Therefore, even if the right and wrong machining surface is required by the drawing, it is necessary to add appropriate allowance on the non machining surface when making the blank, so as to ensure that the dimensions between the non machining surface and the machining surface meet the requirements of the drawing when machining in the machining center.
In the same way, if there is a scale requirement between the pre-processing surface before the CNC lathe processing and the surface processed by the machining center, a certain machining allowance should also be reserved during the pre-processing. It is better to finish all processing contents including the pre-processing surface in the primary clamping of the machining center.