Precision and surface quality of main parts during finishing

Manufacturers of CNC vertical machining centers talk about the process of dividing parts according to the machining accuracy, rigidity and deformation of the parts in the CNC part machining center. The processes should be divided according to the rough and finishing, that is, the roughing is completed first After that, semi-finishing and finishing are performed. For a certain processing surface, it should be completed in the order of rough machining-semi-finishing-finishing.

        During rough machining, the performance of the machine tool and the cutting performance of the tool should be fully exerted under the conditions allowed by the processing quality, tool durability and rigidity of the machine tool-fixture-tool-workpiece system, and a larger number of cutting times should be used to obtain Machining conditions where the remaining amount of each part before finishing is as uniform as possible. The precision and surface quality of the main parts during the finishing process, so the final contour of the part should usually be continuously finished by the next knife during the finishing process. For processing quality, in general, it is advisable to leave a finishing allowance of 0.2-0.6mm. Between roughing and finishing, a period of time is needed to fully restore the deformation of the parts after roughing, and then finish machining. To improve the machining accuracy of parts.

Generally on CNC machine tools, especially on machining centers, parts and procedures can be concentrated to a large extent, that is, parts should complete most or all of the processes that can be processed by this CNC machine tool in one clamping. Concentrated procedures can reduce the number of machine tools and the number of workpiece clamping times, reduce unnecessary positioning errors, and increase productivity. For the processing of the hole system with high coaxiality requirements, after one installation, all the processing of the coaxial hole system should be completed by sequential continuous tool change, and then holes in other locations should be processed to eliminate the effect of repeated positioning errors. Improve the coaxiality of the hole system.

        According to the distance between the processing part and the tool setting point, in general, the part close to the tool setting point is processed first, and the part far from the tool setting point is processed later to shorten the tool moving distance and reduce the idle travel time. For turning, near-to-far is also beneficial to maintain the rigidity of the blank or semi-finished product and improve its cutting conditions. For parts that have both a milling plane and a boring hole, it can be performed in the order of milling the plane first and then boring. Because the cutting force is large when milling the surface, the parts are prone to deformation. Milling the surface first and then boring to restore it for a period of time, and then boring after it recovers the deformation, is conducive to the accuracy of the hole processing. Plane, the hole will produce burrs, flashes, and affect the assembly of the hole.