Numerical control machine tool machines Duan Jian of complex space curved surface to change a method

Summary: Brief narrated pair of conic curved surface to undertake machining a process, cut the account that the phenomenon produces too through analysing spherical milling cutter, use manual process designing (the means) that parameter changes process designing, implementation machines dimensional curved surface on bed of pillow of numerical control of 3 axes linkage. Make in machinery in getting a town, curved surface treatment is all the time relatively difficult, develop as the product, design branch uses curved surface structure increasing. It is important that because this is aimed at curved surface,treatment undertakes technology research is with pressing job. Use treatment of 5 axes linkage to ask to process designing software not just taller, and very tall also to the requirement of the machine tool. Such meetings make the manufacturing cost of the product substantially rise, the article carries parts of pair of some curved surface (the effective treatment research of 1) seeing a picture, put forward a kind to apply to machine tool of 5 axes linkage not just, and the treatment method that can suit equipment of ordinary numerical control. Graph 11 part drawing the surface on this spare parts is Z= ± (X2+Y2)½k is in one of curved surface, in going up, face of parallel Yu Qu divides the plane end its bus, and bus is umbriferous on this plane to curved surface two end are equidistant. Tradition of analysis of 2 treatment craft machines craft to analyse a tradition to machine swing tower spare parts to be on lathe undertake machining, although this kind of method needs very complex tool clamping apparatus, but its treatment precision is taller, but this treatment method is affected by spare parts dimension bigger, the graph shows a part 1 times, the circumgyrate radius of the spare parts is bigger, needs lathe size range of pipe bent is bigger. Because my unit does not have the lathe of this kind of model, accordingly this spare parts cannot use turning to machine. When the curved surface that if the spare parts of place treatment is,rotates by other curve (be like: The) such as hyperbola, parabola, need uses numerical control lathe to undertake process designing is machined. Effective treatment craft (bed of numerical control acute is machined) general and complex curved surface paragraph treatment needs to use machining center of 5 axes linkage, at the same time in the 5 axes in treatment interpolation finishs curved surface; Also can use machine tool of 3 axes linkage to machine a curve to plan to add up to the method of curved surface, namely cutting tool finishs many curve in treatment, choose the span between the curve to make its plan to synthesize the curved surface that needs for place appropriately. (This kind of method has certain limitation) . Craft of 3 kinds of treatment is opposite subordinate list to machine CNC Milling of machining center of 5 axes linkage to machine craft 1) to machine precision than analysing numerical control lathe inferior 5) of cost of 4) of manual process designing of 3) of limitation of diameter of taller 2) treatment suits 1) of swing tower spare parts to machine precision only dimension of taller 2) spare parts restricts 3) special process designing, complex curved surface paragraph treatment needs to use treatment of machining center of 5 axes linkage, the axes of special and spherical milling cutter when treatment must be mixed from beginning to end the law of curved surface to coincide; The treatment means that also can use a curve to plan to combine curved surface undertakes, add man-hour to use special and spherical milling cutter, the curvilinear coincide that and the ideal center line of milling cutter is mixed from beginning to end decomposes. Put in the following problem in be machined actually. The software of treatment difficult problem that basically exists in craft course uses machine tool of 5 axes linkage to undertake machining, need to build model of spare parts space through special plot software above all, process source code of knife course file through generating next, use postposition to handle software program to change source code of knife course file the machine tool code that can identify for machine tool place finally, reach this order input again undertake machining in the machine tool. But because can change those who be program of 5 axes linkage hind in processing software is relatively sophisticated, my unit still cannot complete the development of this software at present, because this cannot use this kind of programming method. Use the precision that its machine manual process designing to basically depend on the amount that treatment site selects in unit area. The process designing method that uses curve of 3 axes linkage to plan to combine curved surface completes the treatment of this spare parts. This method needs to use manual process designing, because this needs much manual consideration, reasonable choose the measure that inserts a dot to assure to machine precision. Because many insertion is chosen to nod in this curved surface, because this uses manual process designing so often unwarrantable calculative accuracy. Appear easily mistake, cannot undertake the program checks the work at the same time, because computational amount is very large, process designing time is accordingly longer, the production of unwarrantable product is periodic. Using this kinds of method is cutting tool axis ideal is an axes, because this has produced an error when craft is designed, need designs an error to undertake early days is analysed to the craft of this technique. Design the rationality of technique in order to ensure, can make sure in machining a process actually product precision asks what make. Its treatment precision basically depends on besides technology design error choose the width between the curve. The hardware choice in the cutting tool in treatment is one of main factors that affect spare parts precision, cutting tool diameter is lesser and OK reduce an error, but wear away in treatment very serious, also cannot make sure the precision of the product asks. Software of means of settlement (parameter changes process designing) because at present I can not use software of 5 axes linkage,undertake process designing is machined. Can use a curve to plan to combine curved surface technique through computation only, below the circumstance that can assure product precision, according to curved surface equation 1, according to blueprint the requirement chooses the treatment interval of axis of Y, Z, use at the same time change parameter of data of axis of X, Y, Z and ask to input its according to process designing of DMU 50V machine tool to the program in, can make treatment software so. Z= ± (the A in X2+Y2)½ctga(1) type is conic half cone angle. Through studying to the treatment of this type spare parts, the author thinks to go up to also can use a curve to plan to add up to the treatment method of curved surface in common CNC Milling, method of its process designing can use advanced language to change parameter of curved surface equation the course that organize a person in, through the program automatic computation generates the coordinate that needs axis of X, Y, Z to nod, using section of handiwork general program ordinal input undertakes machining to the machine tool. Hardware is in process of treatment of this spare parts, used the method of milling of many cutting tool actually, use a diameter namely the spherical milling cutter of bigger Ø16 undertakes rough machining, the spherical milling cutter that uses Ø12 next undertakes semifinishing machining, the curved surface part of the spare parts of finish machining of spherical milling cutter of final use Ø8. Graph the sum of errors that the problem that 2 figures appear in 34 effective treatment and analysis of error of means of settlement machine medium error actually to basically include to machine a process to arise designs the error that has arisen in the process in craft. Because effective treatment process is medium matter of machining complex error is very complex (be like: Quantity of cutting tool, cutting, be out of shape, the) such as production error of machine tool vibration, machine tool, and with craft design error has nothing to do, here does not do an analysis. Because this needs pair of technology only,design error undertakes an analysis. Spare parts craft designs an error to basically come from two respects, the first main field that is technology design error, if pursue 2, the cutting tool in the process is machined to be able to have arisen to cut a phenomenon in circular arc direction in the spare parts, when using this kind of craft to machine a method, be inevitable, its error can use formulary 2(this formula to apply to outcurve face) computation. Through craft design error formula can see, choose when cutting tool diameter relatively Xiaoshi can reduce craft to design an error greatly; And the another because all alone,is a spare parts central part A that reduces an error, bring about machining complex to design greatly too when A angle when the error is bigger, can divide curved surface into a few curved surface paragraph, use circumgyrate tool to hold clip, ordinal treatment each curved surface paragraph, of such treatment by each curved surface whole curved surface of Duan Liancheng can be gotten very tall precision asks. Incurvate face formula can use formula 3 computation. In =R+r-[R2+r2-2Rrcos(180-a)]½(2)=[R2-r2+2Rrcos(180-a)]½+r-R(3) type: The central included angle that the radius A that the curvature radius R that R is treatment dot is spherical milling cutter is treatment dot another error is cutting tool be in what arise along X axis cutting, because cutting tool axis is mixed when the level is mobile,this is X axis produces an included angle, bring about the cutting tool in machining a process to be able to have had cut a phenomenon, this kind of error is OK reductive, if its error pursues 3. Use formula 4 computation, can provide a diameter through reducing a knife. As to the graph 3 in the influence of B horn can be passed reasonable in treatment use tool to install clip to be reduced effectively, of course right now curved surface equation 1 also will change. Because be in,when machining other curved surface X axis direction can have arisen to cut a phenomenon from beginning to end accordingly logical choice rotates the main factor that angle becomes influence craft to design precision. In =r-rcosb(4) type: R is the included angle that the radius B of spherical milling cutter when treatment is dot of the cutting in machining a process and horizontal analyse discovery through designing an error to machining complex, a few when affect spare parts precision main because the home is included angle of axis of part of center of cutting tool diameter, curved surface, X. Carry reasonable option these conditions, can use manual process designing to get relatively the product of high accuracy. Computational discovery is passed when cutting method and parameter choice are machining this spare parts, because select a site more, carry out a program to often need 24 hours by normal treatment, and used the time that holds clip to finish to mill of essence of life from thick mill to achieve 48 hours, because this is in treatment,use the method with thick apart finish machining. Choose when thick mill insert bit of less program, measure as a result of cutting at the same time bigger, choose machine tool rotate speed so inferior, feed is slower; The precision that assures a spare parts is when mill of essence of life, insert a dot more, choose machine tool rotate speed consequently taller, feed is faster. Although this is me,as a result unit first time machines 5 treatment craft the spare parts of curved surface structure, but machine this spare parts through using this kind of method, get eligible product, in explaining this kind of craft designs a method to be machined in a few curved surface, be feasible, but because be in,technique had produced an error in design process, want to undertake an analysis to the machining error of the product above all so, ensure the ability when contented design asks is used. It is at the same time when spare parts demand is higher cannot use this kind of technique 6 suitable scope machine a method this kind to apply to treatment of swing tower curved surface not just, and apply to other airspace curved surface, but method of this kind of treatment also has certain limitation: Above all, the dimension precision of the spare parts and form tolerancepublic errand demand is not high; Next each bits of curvature of spare parts curved surface is worth cannot too big; Because use,choose the method of treatment surely finally, the conference in machining a process has appeared to cut a phenomenon, because this needs consideration,the biggest error is worth, in order to make sure blueprint asks, can use all sorts of tool clamping apparatus of course (be like: Clamping apparatus of all-purpose dividing head, tool) cooperate to use, make curved surface is decomposed for curved surface paragraph the treatment that photograph join can complete whole curved surface. If use,change of course the precision that cutting dot undertakes machining a spare parts will have bigger rise. If pursue,2 medium A can rotate the spare parts relatively an angle chooses the way with minor error can, of course the equation of the spare parts also needs to undertake accordingly gyral. CNC Milling