The digitlization of impeller advocates model and integral treatment
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source:LENA CNC Machining
Impeller is the crucial part of engine, its design and production demand are quite high, raw material is aluminium alloy (heat treatment) undertakes after hot die forging, but its structure is complex, design development cycle is long, its quality affects the performance of air motive force of engine and mechanical efficiency directly. UG is software of unifinication of CAE of ／ of CAD ／ CAM, its powerful function offerred very good substance to build model and capacity of numerical control process designing, the whole process that examines to manage with product data even. The CNC Machining that gives complex curved surface brought very big convenience. Assured to machine precision and treatment efficiency. The modelling of accurate geometry substance of 1 foreword impeller is the necessary premise that impeller machines, rise as what ask to engine function, the appearance of rotor more hasten is complex, the three-dimensional CAD model that studies integral rotor is more and more important. Of rotor lamina data get basically have two kinds of methods, one kind is get several fortified point to next Cheng through going against, one kind is to pass manage fall computation to get several fortified point. The geometrical dimension that converse project is a prototype adopts all sorts of measurement technique (be like: 3 coordinate measure machine, laser to dog appearance, 3 coordinate survey first class) change into file of a data, of the CAD model that builds this part afresh next. Rebuild the process of the spare parts is: Through each sectional inside model value drop uses curve of I second batten to undertake interpolation is calculated, enter Hang Guangshun to handle next. When more to inflection point curve undertakes light is arranged, can use the smallest energy method. The standard that arranges solely is when maintaining only model the inflection point that has the law, the inflection point with purify redundant other, to curvature of blade profile line metabolic ratio did not make a provision. This kind of method can reduce the cycle that designs a part, but the spare parts performance that adds Jrm not can prep above is archetypal. Theoretical consideration is full the blade profile data of the lamina that comes out according to hydromechanical principle computation. After the model of 2 lamina builds the data file that founded UG support, open UG system, build a new Part document, enter the state that build a model. 2. 1 lamina, of batten curve found choose an order from inside menu column, the system shoots a dialog box, the batten in selected curve, guide the Dat format file that already made, the batten curve that the system will close according to data scale. If pursue 1. 2. 2 lamina are founded hypostaticly choose to insert the option of network curved surface in the command from inside menu column. The system will shoot a dialog box, choose the batten curve that already built to string together respectively, the attention unifies initiative element. If pursue 2: The lamina that the graph strings together to contain batten curve is hypostatic, if the blade entity that after concealing batten curve to string together, creates pursues 3, 2. 2. 1 establish hub (of 1) scale hub sectional in the draft below the means that build a model, of scale hub sectional. Build rotor line. (2) builds hub swing tower to choose an order in menu column, the choice makes over a week of circumgyrate of sectional retrace runner shaft together, build hub swing tower, if pursue 4 hub. 2. 2. If the 2 rotor that build other lamina to go individual lamina to load into individual lamina to hub hind pursue 5. Because blade is circumferential all of cloth, choose an order from inside menu column so, the choice wants duplicate lamina, in numerical value of ginseng of the input in text casing 360 ／ N(n is blade several) , successive and duplicate N-1 second, finished N so blade on hub distributing equably, if pursue 6 hub and lamina. If pursue 7 rotor are hypostatic. 2. 3 Baconian summary this chapter is the function of modelling of free curved surface that is based on UG, the three-dimensional substance that undertakes rotor builds a model. Undertake the data document with original lamina handling first, build the batten curve of blade face, tectonic lamina space face, more accurate report gives the curved surface appearance of blade, be helpful for the effective treatment of blade. The treatment of integral treatment impeller of 3 impeller ought to use 5 coordinate numerical control to add a center to finish 111. 5 coordinate are to point to 2 rotational reference axis increase on foundation of 3 translation reference axis (A, b or A, c or B, c) and 5 axes are OK linkage. Because have 2 axis of rotation, bring about 5 coordinate machine tool to rod of a lot of kinds of movement deploys program. Module is machined mediumly in UG software after building a model to finish, the numerical control that machine tool of numerical control of OK and automatic generation can accept adds T to dictate. Traditional impeller treatment method is blade and outline introduce different semifinished product, after adding T figuration respectively, solder blade to go up in outline. This method not only take time is arduous, and all sorts of function of impeller assure hard. UG system contains the 5 axes machine tool of 3 kinds of types oneself, this paper chooses among them circumgyrate ／ to swing model the machine tool undertakes fictitious emulation treatment explains, placing a runner shaft coming back is B axis, revolving stage runner shaft coming back is C axis. Through machine tool navigation implement transfer into machine tool component and cutting tool component, impeller spare parts is put in can undertake machining emulation above revolving stage. Impeller adds T with machine tool of 5 coordinate numerical control, because the twist of blade is very big, flow path is narrower, cutting tool is reached on blade want inside flow path reasonable swing, ability prevents impeller to be cut too, get the Dao Wen that arranges solely. From the graph the three-dimensional model of 6 impeller can see, when the lamina that add man weighs suddenly underside, cutting tool axis must swing between lamina of two photographs adjacent, cannot touch with blade photograph, that is to say, blade is the attrib border condition that flow path machines. Way of iteration of axis of a kind of cutting tool offerred in UG axis of one interpolation cutting tool (Interpolated M Axis) , the feature that this kind of means can assign through be in defines vector direction to control cutting tool axis, produce the vane wheel that gives complete high quality thereby. According to blade face feature, depend on cutting tool and the means of music surface contact to classify, lamina of treatment of milling of 5 coordinate numerical control face can be divided for mill of side edge of " line contact "() with " of " point contact means of two kinds of figuration. But to side edge mill the whole side of cutting tool and blade photograph are contacted, the spring back impact when be being machined to thin lamina is big. So side mill machines this kinds of lamina is approximate treatment method only. To point contact, this kind of method has a few inevitable drawback: To curving the lamina with fiercer degree, because blade is empty a distance is closer, in machining a process avoid very hard with the interference between photograph adjacent lamina; But " of " dot treatment should compare " line to machine " the spring back that machining generation of Bao Xie a short while is small, when reason is adding T edge round part, those who use is means of " of " dot treatment. Machining means in the integral treatment of impeller so is to use " to nod treatment " and " line to machine " photograph union. Practice of 4 last words makes clear, use technology of CAD ／ CAM, use machine tool of 5 coordinate numerical control, the three-dimensional substance that undertakes rotor in the light of the structural characteristic of impeller spare parts builds a model, be helpful for more the intuitionistic to designs workpiece observation of figure, reduced actual production to process medium waste greatly, cut the design is periodic, reduced manufacturing cost. CNC Milling