Fictitious treatment builds modular research

Summary: The article is aimed at fictitious of production crux technology -- the research that fictitious treatment had development. The milling when the needle machines a process, put forward a kind of process to emulate a model. This model is passed in geometry ply of cutting of instantaneous of computation of the real time in emulating is calculated cutting tool is oscillatory, emulate geometry thereby emulate organic ground union to rise with physics. Emulate the rationality that proved this model with experimental result. The further research of this method has important sense to building trends of geometry of treatment process physics to emulate a model. At present manufacturing industry is faced with 1 foreword to be challenged tremendously, at the same time economic development also raised taller requirement to manufacturing industry, the generation of fictitious production technology is to get used to this kind of challenge. It is OK to use fictitious production technology undertake assessment to the function of the product, exterior, quality in products plan phase, shorten thereby the development cycle of the product, improve manufacturing efficiency. Fictitious processing technique serves as one of keys of fictitious production technology, its study more and more be taken seriously. The key that realizes fictitious treatment is fictitious treatment builds a model, undertake the reasonable ability that build a model realize pair of treatment quality in fictitious treatment better to machining a process only forecast and control, the sense of reality that just can reflect fictitious treatment better and be enmeshed feeling. 2 fictitious treatment build a model to machine a process to build a model fictitious treatment process is have the aid of emulates a technology at virtual reality technology and computer, to the treatment of the spare parts the process undertakes all-around imitate. Milling treatment is a kind of when undertake complex part is machined important step, study milling machines a process to have the common sense that comparative. It is with milling treatment process below the exemple is right fictitious treatment is emulated build a model to undertake demonstrative. Of milling system simplify the model is shown 1 times like the graph. The system simplifies the vibration that is two mutual and perpendicular direction. Kinetic equation of the system is Mxx.

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+ Cxx.

+ Kxx=Fx(t)}myy.

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+ Cyy.

+ in Kyy=Fy(t)(1) type: Mx, cx, kx -- X, Y to X of quality, damp, stiffness, y -- it is X, Y respectively to displacement Fx(t) , fy(t) -- the cutting force that changes along with time type (1) melt into is as follows formal X.

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+ 2xnxx.

+ Wnx2x=(wnx2/kx)Fx(t)}y.

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+ 2xnyy.

+ the Xx in Wny2y=(wny2/ky)Fy(t)(2) type, wnx, kx, xy, wny, ky is X, Y respectively to structural damp is compared, natural frequency and stiffness. When begging the oscillatory displacement that sees two way, measure above all these 6 parameter, of such systems be out of shape concerned with cutting force only. The treatment method with the different computation that machines systematic cutting force the computational method of its cutting force is not same also, with respect to milling force character, cardinal principle of its calculation method is similar, it is with ball head milling cutter below the exemple is right milling force has consideration (2) seeing a picture. line of blade of cutting blade edge cent is of countless paragraphs small, each paragraphs small regard a lathe tool as, according to circle of theory of cutting of bevel angle orthogonality, graph of yuan of small cutting force DFr=tsdAcsinØcos(Ø+b-ae(3) 1 milling process simplifies the model pursues signal of knife of iron of 2 balls head is schematic in: DFr -- small yuan of cutting force Ts -- the shear strength DAc of material -- small yuan of instantaneous cutting area (cut with instantaneous thick about) Ae -- effective before horn Ø -- cut horny B -- angle of friction among them, the method that cuts horn, shear strength and angle of friction to be able to use a test establishs experience formula in the light of different material. Follow what DFr is in in this tooth move coordinate to fasten OXYZ to decompose for DFx, DFy, DFz, in changing them to coordinate of whole cutting tool to fasten OXYZ, DFi(q)=[dFX]=[cosysiny0][dFx]dFY-sinØcosØ0dFydFZ001dFz(4) type is medium: DFi(q) -- I of blade line small yuan of cutting force DFx, DFy, DFz -- DFr is in the DFX of component of force in OXYZ, DFY, DFZ -- DFr the Q of component of force in OXYZ -- blade line is in the included angle Y in OXYZ -- the corner coming back of milling cutter next can will small line of yuan of blade of force edge cutting is integral, the vector that gains strength of the cutting on whole blade line and, and all blade on-line that participate in cutting force addition, type of QjudFi(q)qjl(5) of ∫ of Fi=n ∑ J=1 is medium: Fi -- I J of vector of force of blade on-line cutting -- I the knife line segment that this cutting participates in on blade line counts Qjl -- what participate in cutting this paragraphs is small yuan Qju of integral floor level -- what participate in cutting this paragraphs is small yuan, after the blade line equation that gets a curve, through edge blade line integral can get cutting power. But paragraph of number that needs to get the blade line that participates in cutting and fluctuation are restricted, this need is emulated by geometry offer. Geometrical copy Zhong Jianmo and physical copy are compositive really by the analysis above knowable, what should realize physics to emulate is compositive, when blade of need computation cutting and workpiece intersect cut paragraph amount and cut, cut a corner. These parameter can be emulated by geometry get. The geometrical copy that processes a process is body of cutting tool scanning and workpiece demand the process that make essentially really, in geometry the workpiece in emulating uses B-rep modelling method to express. The method that this literary grace approachs with polyhedron will depict workpiece and excision material. To ball head milling cutter, the blade line equation of cutting blade is X=Rcos(an)sin(q)}Y=-(½)Rsin(2an)[cos(q)-1]Z=-R[cos2(an)cosq+sin2(an)](6) type in: X, y, z -- the coordinate R of blade line -- the radius An of ball knife -- of cutting tool effective before horny Q -- in the included angle treatment of line of cutting tool blade and reference axis, to position of interpolation of each cutting tool, line of attainable tooth blade and workpiece intersect hypostaticly paragraph, concrete move is as follows: Emulation data expresses X to mode stiffness 3 × 105N/mmY to mode stiffness 3 × 105N/mmX scans cutting tool to 800r/min of rotate speed of main shaft of natural frequency 425Hz to natural frequency 417HzY to S/mmX of · of mode damp 16N to S/mmY of · of mode damp 13N body and workpiece substance intersect, get two parts substance, already excised data system and workpiece namely. cutting blade line mixes blade to already excised data system to intersect, get blade line the line segment in already excising data system. Computation of these line segment cut horn and cut a corner, era enters type (5) seeks solution. 3 emulation experiments are aimed at above built mathematical model, to undertaking emulation with circular arc milling point-blank. Emulation data sees right table. Can get via emulating 3 ～ pursue is like a graph the oscillatory displacement graph of 4. (Result of A) solid face (B) emulation result pursues Xiang Zhen of X of 3 straight path moves displacement (result of A) solid face (method X Xiang Zhen moves 4 circular arc of graph of B) emulation result displacement pursues knowable from oscillatory displacement, when aggravate of second birth Yizhen, as the accretion of corner oscillatory displacement also increases. Because instantaneous cutting ply adds an ambassador to get dynamic cutting force to increase,this basically is, bring about oscillatory displacement to greaten thereby. Can see it is OK to emulate at the same time well imitate second birth quite brace up the case of aggravate is as good as experimental result be identical. 4 epilogue use physics and the method that geometrical photograph combines to undertake building a model, can more true the earth's surface shows whole treatment process, can think appearance of form of analysis of spare parts machining error, surface is emulated thereby, the setting of the characteristic analysis of the spare parts, parameter and optimize, treatment status is forecasted and the analysis provides a basis. CNC Milling