Complex model the CNC Machining of the face

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1. Complex model the main treatment method of the face is complex model the child that the face makes medium occurrence in tool and mould is production of rate of big batch environs. The forging die that uses in auto industry and die appear to basically be made with manual means before in numerical control machine tool. To 70 time later, numerical control machine tool is made in tool and mould in received wide application, complex model the basic outline of the face is machined with milling normally, make at first all round numerical control machine tool is 3 axes linkage. After entering 80 age, the milling machine of 5 axes linkage is in complex model wide application received in face treatment, the workpiece outline after milling has been close to the final figure of workpiece very, but last finishing working procedure still is operated for handiwork. 80 time evening, work up of technology of high speed cutting is mature, its application in industrial production from etc of machine tool, cutting tool relevant technology respect got be perfectinged ceaselessly. As a result of high speed cutting can twice land raises feed rate, make reduce feed span to become a possibility below the case that dropping manufacturing efficiency so, it is the figure that raises workpiece thereby precision and reduce a list and surface roughness offerred premise condition. Current, the workpiece majority that high speed milling has machined already needed the working procedure of last manual treatment no longer, and can throw directly use. Material of new-style cutting tool is like alumina base the ceaseless development that pottery and porcelain, nitrogen changes silicon radical pottery and porcelain, cermet, hard alloy to exceed good plated film especially, make stiff dough milling becomes a possibility. Of the mould model the face can be in figuration of the milling after quenching, can avoid to quench again after milling and be caused thereby be out of shape. Simplified to machine a process already so, can raise workpiece precision again. Additional, forging to make medium application in the mould as nicety, the mould semifinished product after forge is hit has had his basic form, the photograph when the mental allowance of place remnant and milling of whole semifinished product is compared already negligible, below this kind of circumstance, outside dividing milling, still can undertake machining through efficient grinding. Compare with photograph of stiff dough milling, efficient grinding not only the appearance precision that can improve work, and the exterior surface roughness that can improve work. The method of efficient grinding is very much, use normally have grinding of high speed of spherical emery wheel and small diameter the arenaceous belt of belt annulus grinding. 2. Complex model the technology of face CNC Machining is crucial 1.

5 axes are muti_function the common three-dimensional and free curved surface in machining center tool and mould is normally on the machining center of 5 axes through traffic undertake cutting. Because the material of workpiece is alloy steel or tool steel mostly, the structure of the machine tool and numerical control system must consider to machine the requirement of the productivity in the process and workpiece precision, undertake for the basis with this proper layout is mixed optimize. Be in to assure a machine tool cutting does not happen when all sorts of mould material too big be out of shape, when layout of affirmatory machine tool, machine tool stiffness should be put in the first place. Larger 5 shafts machining center, use structure of dragon door type likely, a few in machining center also uses the 5 rods of small size sometimes pillar type construction. Since entering 90 age, complex model face aborning undertakes machining with the means of high speed cutting entirely almost. The purpose is to improve manufacturing efficiency, reduce the cost of the product, the appearance precision that improves work at the same time and reduce exterior surface roughness. To satisfy the need of high speed cutting, the main shaft of the machine tool uses electric main shaft without an other place almost. What place of basis of main shaft rotate speed uses cutting tool diameter is different undertake infinitely variable speeds, rotate speed limits from minutely thousands of turn to tens of thousands of turn. The drive system of slip also is different from groovy machining center when high speed cutting, commonly used system has deputy drive of nut of high speed guide screw and drive of linear electric machinery, the oldest feed rate can achieve above of 100m ／ Min. Machining complex model when the face, the numerical control system of the machine tool also must satisfy a few special requirements. For instance, complex model the CNC Machining order of the face is average generate on software of CAD ／ CAM, model the program of the face often needs to count byte (Byte) store space, deliver numerical control program to had been impossible with floppy disk. So numerical control system must have the function with net of couplet of all of other computer science department, so that receive numerical control order from CAD ／ CAM directly. In addition, numerical control system still must use advanced control technology, the look up before asking to have above all (LookAhead) function. That is to say, before the machine tool machines some contrail, data system undertakes be analyticed beforehand to wanting the curved surface of treatment, of the curvature that nods each according to curved surface and dot of each photograph adjacent join relation, adjust the feed rate of the machine tool appropriately, so that highest productivity is achieved below the premise that assures workpiece precision. Process the dynamic error in the process to decrease, of error of new-style data system servo corrective the differential of scale of series connection type that collects in order to to go to no longer is integral (PID) adjuster, use however have compensatory conditioning by the condition parameter such as the position and speed implement, it is OK to use this kind of regulator error of comb-out drive lag, those who because clearance or attrition are caused,compensate is nonlinear error, the certain vibration of OK even and quits machine tool, achieve thereby increase workpiece appearance precision and the demand that reduce exterior surface roughness. 2.

System of cutting tool of cutting tool system is being machined complex model the opposite when the face produces efficiency and treatment quality to have conclusive effect. When choosing cutting tool system, must above all from be machined appearance of year of spare parts geometry set out, reasonable the sort that uses cutting tool. Be like the work that the graph shows 1 times, the geometrical appearance difference of each place is very big. If use ball head milling cutter to undertake machining only, must choose the ball head milling cutter with very small diameter, improve treatment efficiency very hard so. Additional, the circular arc radius of certain place is very small, although use very small ball head,milling cutter also cannot be machined. Accordingly, considering manufacturing efficiency and workpiece appearance the requirement of two respects, machining complex model the milling cutter that other type must provide on the machining center of 5 axes linkage of the face, if carry milling cutter and 3 blade milling cutter,wait. Graph 2 be a few choose milling cutter type. Want dimension to allow only, no matter be the cutting tool of which kinds of appearance, cutting blade appropriate uses machine clip but dislocation mill razor blade. Such cutting tool can have a variety of combination as a result of bit and cutter hub, and bit and cutter hub can have production in different company, can form so large-scale specialization production, be helpful for improving the quality of cutting tool already, be helpful for reducing the manufacturing cost of cutting tool again. At present on the market but dislocation razor blade, use the hard alloy bit of CVD plated film mostly. Fight abrasiveness to achieve taller bogus, but dislocation razor blade all is used multilayer plated film. Than knowing to use Al2O3 can increase the chemical stability of bit. Use TiN and TiCN to be able to enhance the wearability of bit. To enhance the sharp rate of bit, plated film is generated besides method of CVD of usable low temperature outside, still can arise with PVD method. Some treatment are very strict to the requirement of bit, bit should have sharp cutting blade already, in order to reduce the surface roughness of finish machining surface, want to have extremely tall wearability again, in order to assure the appearance precision of workpiece. Below condition of this kind of sex, must use the combination of a variety of plated film. Some razor blade use the no risk at all on the process to ensure, plated film number of plies can amount to 100. 3.

Closely related speed of the optimizes cutting tool life of process and feed, cutting and cutting deepness. Optimal cutting dosage often a very little scope, want to undertake deciding according to particular cutting tool and workpiece material circumstance. In addition, cutting strategy if: Take the program of cutter track diameter, arrow of law of curved surface of cutting tool axes (the magic art that curved surface chooses in this to direction) or edge curved surface cuts arrow (the tangent way that curved surface chooses in this) different kind, also be treatment complex model a of the face decisive factor. It is affected not only by the exterior surface roughness of treatment workpiece, also affect the appearance of workpiece and dimension precision. Graph 3 it is the different cutting strategy that when machining curved surface of form of a column, uses. Cutting undertakes in circumferential direction, cutting tool contrail should undertake interpolation of two axes linkage. When direction of the generatrix that use an edge undertakes cutting, cutting tool needs monaxial interpolation only. Additional, different cutting method, of cutting tool wear away the difference is very big, the cutting tool when suitable mill wears away apparent under go against mill, when milling of move back and forth wear away to be more than one-way milling far. Machine the stability of the process to rise, when optimizing cutting strategy, what must assure cutting is successional, reduce knife motion and idle stroke as far as possible at the same time, so that shorten cutting time. Thick mill steel when, must assure to arrange mill continuously, reduce edge to estimate fluctuant peak value in the cutting in cutting process as far as possible. When processing the work that the graph shows 4 times, if use the travel that graph 5a place shows to cut orbit partition,machine; The motion of cutting tool is very unreasonable, cutting condition very not ideal, handling time needs 33min, workpiece surface surface roughness is 6 ～ 9 μ M. If converts the group that graph 5b place shows cuts orbit partition to undertake machining, handling time needs 27min about, the surface roughness of workpiece also can fall to 2 ～ 4 μ M. CNC Milling CNC Machining