Spare parts of large sculpture curved surface technology of CNC Machining of 5 axes linkage

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One, preface is in machining industry, the treatment of spare parts of large sculpture curved surface, use a convention more " sand mold casts → handiwork shovel to grind → stereo example to check " technique treatment, because stereo example production precision is inferior and influence of its geometry metabolic, make the treatment precision of spare parts of this kinds of curved surface rises hard. Be in as technology of contemporary numerical control of machining industry gain ground increasingly, brought revolutionary progress to machining industry stage by stage, and the development as computer technology, make CAD/CAM technology had great progress, appeared milling machine of boring of numerical control of 5 axes linkage and a few outstanding CAD/CAM software, among them SDRC/CAMAND software is compared in respect of process designing of CNC Machining of 5 axes linkage agile. Author basis produces medium practice situation actually in my company, the technology of CNC Machining of 5 axes linkage of spare parts of curved surface of essentials introduction sculpture. Be opposite at present the treatment of spare parts of large sculpture curved surface, undertake in order to adopt way of line of parameter of curved surface of edge of milling cutter of big diameter face machining is optimal treatment means, means of this kind of treatment has treatment precision and treatment efficiency are tall, quality of spare parts surface is better and position of cutting tool cutting is excellent characteristic. 2, the three-dimensional model technology of sculpture curved surface is opposite to finish the CNC Machining process designing of curved surface, need to give the three-dimensional model of curved surface in the modelling on the computer above all. The design data of sculpture curved surface is described with latticedot matrix data normally, and the origin of data of curved surface lattice basically has two kinds of kind: One kind is to adopt design measure, by design personnel basis the design of the product is academic, get data of this kind of lattice through computation, its often have the rule to give out by certain regulation again, three-dimensional model is relatively easy; Another kind is the wooden model prototype that designs by hand through be opposite or objective, use three-dimensional measuring instrument implement measure the data nodding the cloud that gets curved surface, this class number distributings according to latticedot matrix without exact pattern, curved surface is three-dimensional modelling is opposite more difficult. So, according to curved surface the different situation of primitive data lattice, the three-dimensional model of sculpture curved surface can distribute the curved surface model of the curved surface modelling that is regular lattice and irregular lattice. 1. The curved surface of sculpture of lattice of three-dimensional model regulation of curved surface of regular lattice sculpture is to point to data of curved surface lattice to give out strictly according to definite pattern. Normally, cent of lattice of curved surface data is a certain number of data of node of parameter batten line, three-dimensional model uses modelling of NURBS curved surface to finish place to need sculpture curved surface. The modelling move in SDRC/CAMAND software is described below. (1) sculpture curved surface primitive lattice data is used " Pointset " the function makes bit of part (Pointset) , the attention should make independent point part according to every parameter batten, the parameter batten that what the graph shows 1 times is one sculpture curved surface chooses volume figure. Graph market of 1 batten spot pursues (2) use " B-Spline " function, the choice is used " Thru Points " and " Non-uniform " parameter, each batten that chooses a correspondence directly next orders part, generate tectonic curved surface all parameter batten, what the graph shows 2 times is the parameter batten graph of one sculpture curved surface. Graph 2 parameter batten pursues (3) use " Modeling " " Surface " function, carry out " Lofted Surface " child function, after choosing every batten curve by certain order, click affirm, generate this sculpture curved surface. What the graph shows 3 times is the sculpture curved surface that uses this method to generate three-dimensional computer model. Graph model of curved surface of sculpture of 3 regular lattice 2. The three-dimensional model of curved surface of sculpture of the data that nod the cloud nods data of cloud curved surface is to show data of curved surface lattice is not accurately give out according to definite pattern, after cannot generating a batten curve first, give somebody a new lease on life curved surface will get model of better curved surface of this kind of sculpture. Because this is used only " curved surface of modelling of the data that nod the cloud " function, and still do not have similar function in CAMAND, i-DEAS of our have the aid of is medium in practice " Fit Points To Surface " function, create dot cloud curved surface, it is CAMAND file format in the changeover in I-DEAS software next, use a model as numerical control process designing with its. The graph instructs the computer of the data that nod the cloud that is one sculpture curved surface 4 times three-dimensional model attempt. 3, the design of craft of CNC Machining of large sculpture curved surface is made in actual production in, the CNC Machining of 5 axes linkage that should implement parts of pair of large sculpture curved surface, the outfit clip that should solve curved surface part above all seeks square record, how does the consideration define work at 0 o'clock, to the knife dot, treatment uses cutting tool plan and detailed treatment order to wait. 1. The outfit clip of CNC Machining of large sculpture curved surface searchs principle to spare parts of curved surface of general and large sculpture, its install clip to search to having certain law but abide, pass an analysis so, large sculpture curved surface can be divided it is two kinds big, its install clip to search the principle is as follows. If there is planar, round cylinder on spare parts of sculpture curved surface,wait for diagnostic datum plane, use this to wait for diagnostic face planarly to search as outfit clip fiducial, can simplify so search process, raise outfit clip to look for forward efficiency, make sure curved surface searchs precision. If sculpture curved surface is comprised by sculpture curved surface entirely, what did not decide is fiducial, so general be cast on curved surface spare parts or solder on search plane piece, annul Kong Huo is fiducial annul etc auxiliary search fiducial, those who use large curved surface is three-dimensional measure technical measure, and benefit maneuver considers machine software comfortable to match a technology to get semifinished product surplus distributing circumstance, will coach of spare parts of sculpture curved surface search. Of course, these two kinds of means are with what decide part of large sculpture curved surface above all is fiducial, after that CNC Machining program in order to search fiducial undertake machining is guiding ideology. Nowadays, some manufacturer also have kind of another kind of craft. Decide fiducial large sculpture curved surface to notting have, its immediate freedom is placed go up in machine tool workbench, distributing by certain reseau to curved surface after outfit clip is reliable undertake measuring a place, occupy the number that measure a place reconditioning next, find out curved surface to concern in the position of free space, ensure the mental allowance of curved surface, adjusting treatment coordinate is, have transition to CNC Machining program, return a machine tool to complete the treatment of pair of this spare partses again finally. Means of this kind of craft, what the biggest advantage depends on need not deciding is fiducial into luggage clip searchs, spare parts freedom is placed. But from on the other hand for, means of this kind of craft, increased a machine tool to machine auxiliary time, the data of processing is more, also brought difficulty to manufacturing organization. 2. The CNC Machining cutting tool of spare parts of large sculpture curved surface chooses the CNC Machining of 5 axes linkage to spare parts of large sculpture curved surface to use cutting tool, it is beautiful in order to use treatment of milling cutter of big diameter face. At present famouser tool manufacturer has Sandvik, Ingersoll, Kennametal, Seco to wait, among them the milling cutter of face of round razor blade of CoroMill 200 series of Sandvik, suit the semifinishing machining of spare parts of sculpture curved surface and finish machining particularly; The 220/221 series cutting tool of Kennametal company is had impulse withstand as good as tigidity wait for an advantage, suit rough machining fast engorge knife measures treatment, what the graph shows 5 times is the cutting tool picture of Sandvik and Kennametal company. The diameter that chooses cutting tool should decide according to the curvature size of spare parts of sculpture curved surface, the principle is the radius of the smallest curvature that cutting tool radius should be less than sunken curved surface of sculpture curved surface, but also should not be too small, will make machine loss of efficiency otherwise. Part of too large to curvature radius change sculpture curved surface, also can differentiate whole spare parts into different area, choose the cutting tool of different diameter, in order to improve treatment efficiency. 4, knife of 5 axes CNC Machining the knife of CNC Machining of 5 axes linkage of computation and spare parts of emulation sculpture curved surface computational means has INTERP in CAMAND software (interpolation) , NORMAL (law to) , TILT (tilt) with TANGTO (tangential) etc a variety of, but to spare parts of large sculpture curved surface, the most commonly used is with TILT means is machined, the cutting tool axis when means of this kind of treatment is machined and arrow of law of cutting dot curved surface become certain around dip (Lead/Lag Angle) or list horn (Right/Left Angle) , what the graph shows 6 times is sketch map of TILT means cutter shaft. 1. Knife of CNC Machining of 5 axes linkage computation is in CAMAND software, machine spare parts of sculpture curved surface with TILT means, its knife computational process: Choose above all " Numerical Control " " Flowline Surfaces " function, "Flowline Surfaces " the treatment of parameter line direction that means of this kind of treatment is edge curved surface actually; Next set knife name (usable " New " or " Rename " function) , choose treatment to coordinate is fastened and have knife place, the cutting tool parameter with corresponding reintroduce (parameter of size of shape of blade of length of cutting tool diameter, cutting tool, cutting, cutting) , set parameter of knife of good pass in and out, after choice interference checks curved surface and set parameter, click a knife again computational function, the choice machines curved surface and definition cutting direction and cutter shaft control means TILT fashion, general setting adds pitch part, namely pitch of edge cutting direction a 2 ~ the angle of 10 ° ; The 5 axes linkage that achieves this curved surface finally machines a knife computation. The graph shows the 5 axes that are one sculpture curved surface 7 times to machine a knife. Graph the 5 axes of curved surface of 7 some sculpture machine a knife 2. Cutting is emulated and the machine tool is emulated to spare parts of large sculpture curved surface, because semifinished product cost is high, and the safety for machine tool, cutting tool and tool, in knife of CNC Machining of 5 axes linkage after computation is finished, must undertake cutting is emulated emulate with the machine tool, check a knife validity, the machine program that end up with can be used at actual production to make. In CAMAND software, a simple cutting examination and machine tool are emulated, can satisfy common emulation requirement. If need to emulate a tool accurately, should use the Vericut software of more professional CGTech corporation. This software not only can undertake cutting is emulated emulate with the machine tool, and still have can optimize a knife the characteristic such as orbit. Describe the emulation in CAMAND software simply only here. To 5 axes knife cutting is emulated, can be checked and amend cutting tool advanced foreword 5 axes knife in computation cut a phenomenon too. General, above all be machined face apply colours to a drawing is chromatic, use next " Simulation " the function is right knife the interference case that progressively imitate examines cutting tool, if had had,be cut and collision happening, must recount or modification knife. Emulate to the machine tool, we basically check NC milling head (large milling machine of boring of door of 5 axes dragon is means of milling head of two axes NC more) the interference circumstance with workpiece, clamping apparatus, accordingly, can build the three-dimensional model of NC milling head according to appearance of milling head of NC of actual machine tool and dimension, use next " Simulation " the function undertakes plus NC milling head the machine tool is emulated, can examine the interference case of milling head giving NC, cutting tool and clamping apparatus, workpiece. If the graph is shown 8 times,the machine tool emulates a picture. 5, 5 axes knife the 5 axes linkage that postposition processing is achieving curved surface machines a knife after computation, after still needing to pass, buy processing technology finishs the Dao Weiwen intermediate changeover becomes program of code of G of level-headed of numerical control machine tool. The Dao Weiwen in CAMAND it is with point of a knife dot coordinate and cutter shaft vector give out, so postposition processing must become knife digit according to changeover value of coordinate of X, Y, Z, B, C. The numerical control system according to specific machine tool and machine tool parameter (be like journey of each reference axis, speed of the biggest feed, rotate speed) design postposition processor, the postposition in the Main NC that uses CAMAND next handles a function, it is digit of 5 axes knife according to changeover the G code program with executable system of machine tool numerical control. 6, the processing technique of 5 axes linkage of spare parts of large sculpture curved surface can solve the last word effectively the contradiction between precision of treatment of this kind of spare parts and treatment efficiency, this kind of technology involves the computer to assist modelling of three-dimensional curved surface, the much discipline such as CAM and machining engineering technology is integrated technology. In the treatment of 5 axes linkage that the technical positive result that the author gets research uses blade of runner of large hydraulic turbine actually, obtained very good technology economic benefits, enhanced competition ability of my company market greatly. CNC Milling CNC Machining