Machining working procedure to plan is to point to whole process, cannot be judged with the treatment of the property of some working procedure and some surface. Have some of fixed position datum plane for example, need to be machined very well and truly in rough machining phase even in semifinishing machining phase. Sometimes to avoid dimension catenary conversion, in finish machining phase, also can arrange the semifinishing machining of certain and less important surface. After the treatment method that determined spare parts surface and treatment phase, OK the treatment of each surface in phase of will same treatment is combined a certain number of labor situation. 1. Machine the spare parts that the method that working procedure differentiates machines on numerical control machine tool, the principle that centers by working procedure commonly differentiates working procedure, differentiating method has the following kinds: (1) by place use cutting tool differentiates with same the process that completes cutting tool serves as a working procedure, this kind differentiates the case with the more work surface that the method applies to workpiece. Machining center often uses this kind of method to finish. (2) the process that installs a frequency to differentiate to install clip to be able to be finished with the spare parts by workpiece serves as a working procedure. This kind of method agrees with the spare parts with treatment not much content, below the premise that makes sure the spare parts machines quality, outfit clip finishs entire treatment content. (3) differentiate to regard a working procedure as the process of that one part that completes in rough machining by thick finish machining, regard another working procedure as the process of that one part that completes in finish machining. This kind differentiates the method applies to a spare parts to have intensity and hardness demand, need has heat treatment or spare parts precision asks taller, need effective purify internal stress, and after the spare parts is machined, be out of shape bigger, need undertakes by phase of thick, finish machining differentiating spare parts is machined. (4) by treatment place differentiates will finish identical model the process of that one part of the face serves as a working procedure. To machining the part with much and more complex surface, should reasonable arrangement CNC Machining, heat treatment and the order that assist working procedure, solve good working procedure between join problem. 2. Machining the principle spare parts that working procedure differentiates is formed by many surfaces, these surfaces have his precision demand, there also is corresponding precision demand between each surface. To achieve the design of the spare parts precision asks, machine ordinal arrangement to should follow certain principle. (1) first thick hind the order that the treatment order of each surface does treatment according to rough machining, semifinishing machining, finish machining and light has the principle of essence of life, the purpose is the precision that raises a spare parts to machine the surface stage by stage and exterior quality. If the whole face of the spare parts all is machined by numerical control machine tool, working procedure arranges the order that presses rough machining, semifinishing machining, finish machining commonly to undertake, semifinishing machining and precision work have again after rough machining is finished entirely namely. When rough machining but fast purify is major mental allowance, again ordinal finish machining each surfaces, can improve manufacturing efficiency so, can assure the treatment precision of the spare parts and exterior surface roughness again. This method applies to the treatment surface with positional precision higher demand. This is not absolutely, be like faster to requirement of precision of a few dimension treatment face, the stiffness that considers a hardware, be out of shape reach the requirement such as dimension precision, the order that also can consider these to machine the surface to press rough machining, semifinishing machining, finish machining respectively is finished. Faster to precision requirement treatment face, between working procedure of thick, finish machining, the spare parts had better lay aside period of time, the stress of spare parts surface after coarsen is machined gets be releasinged completely, reduce the stress deformation of spare parts surface, such is helpful for that raise the treatment precision of the spare parts. (2) datum plane machines a principle first at the beginning, always use as the exterior treatment with standard precision work comes out, because locate fiducial surface is accurate, the error that hold clip is small, so the treatment process of any spare partses, always undertake rough machining and semifinishing machining to fixed position datum plane first, have precision work even when necessary, for example, axis kind the spare parts always undertakes rough machining and semifinishing machining to fixed position datum plane, have precision work again. For example axis kind the spare parts always is first machining center aperture, it is essence of life with central aperture face and fixed position aperture again department of standard treatment aperture and other surface. If datum plane of essence of life is more than, should mix according to the order of fiducial changeover the treatment that the principle that raises treatment precision stage by stage will come to plan datum plane. (3) first principle of the aperture after the face to casing kind, bracket kind, airframe kind wait for a spare parts, planar outline size is larger, stabilize quite with planar fixed position reliable, reason should machine plane first, aperture is machined after. Such, make follow-up treatment has a stable and reliable plane to regard fixed position as datum plane not only, and in level off apparently machine aperture, treatment becomes a few easier, also be helpful for raising the treatment precision of aperture. Normally, can differentiate by the treatment place of the spare parts working procedure, process simple geometrical form first commonly, complex geometrical form is processed after; Machine the place with inferior precision first, the position with higher precision is machined after; Machine plane first, aperture is machined after. (4) first inside hind outside principle to accurate sleeve, the coaxial of the circle outside its and aperture spends a requirement taller, use commonly first the round principle outside aperture hind, namely first beyond the circle regards fixed position as standard treatment aperture, again with precision taller aperture regards fixed position as the circle outside standard treatment, taller coaxial is had to spend a requirement between the circle outside can assuring so and Kong Zhi, and use clamping apparatus structure is very simple also. (5) the principle that reduces the number that change a knife is in CNC Machining, the ordinal arrangement that should enter treatment place by cutting tool as far as possible processes order, this is not affecting the premise that machines precision to fall with respect to the requirement, reduce the number that change a knife as far as possible, reduce idle stroke, save auxiliary time. After the spare parts holds clip, use as far as possible same finish cutting tool more treatment surface. After all place that when a cutting tool the likelihood that finish machines, become some of prior operation to issue working procedure as far as possible, change a knife to complete precision work again next or machine other position. To a few not significant position, use as far as possible same finish cutting tool same a labour the treatment of much talk working procedure. (6) when the outline of inside and outside that the principle of successive treatment closes partly in treatment or closes, answer to avoid the halt appearance in CNC Machining as far as possible. Below the balance position that because this one machining complex is in spare parts, cutting tool, machine tool,trends is in temporarily in machining a process, if equipment installs eduction to show phenomenon of abrupt feed idle as a result of numerical control program, because cutting power can decrease apparently, with respect to the steady state that can lose original machining complex, make cutting tool leaves nick or dent in stand point. Accordingly, feed idle appearance should avoid in outline treatment, in order to assure the treatment quality of the spare parts. CNC MillingCNC Machining