The computer emulates the technical application in grinding temperature field

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Summary: The computer that built grinding temperature field emulates a system, those who realized pair of grinding temperature field forecast reach optimize. Use this to emulate a system to be mixed to dry type wet grinding temperature field undertook emulation and reach three-dimensional isotherm pursues, be opposite to study each machine parameter the influence of grinding temperature field provided academic basis. 1 foreword grinding is the accurate treatment method with a kind of wide application. In the research that machines to grinding, because the understanding to machining mechanism is limited, because this is right,grinding adjusts majority actually of treatment process is to rely on trial and error procedure (the much experience knowledge that accumulates by handlers place namely) will undertake, analyse a model about grinding temperature especially, obtain through only factor more. As computer function rise increasingly, the emulation technology application in industry is wider and wider, to grinding academic research brought new thinking, make we overcome the limitation of traditional research technique likely, study the change of temperature of the grinding in grinding process deep, the model of theory of grinding temperature field that builds a system. The performance that emulate even if forecasts a product to fall in real environment below imitate environment and feature (trends and static) , it was included from build a model, bring to bear on load and tie go to those who forecast a product to fall in true condition to answer wait for a series of measure. Pass the observation of pair of emulation experiment processes and estimation, the emulation that gets system be emulationed outputs parameter and main character, will estimate and conclude from this the true parameter of effective system and real property. Computer of emulation technology have the aid of, the change of all sorts of grinding temperature field that can get differring inputting parameter falling in complex grinding treatment process, machined mechanism to create a condition to study grinding deep thereby. The 2 mathematical models that build grinding temperature field are used finite yuan of maths model that the law builds grinding temperature field. Because field of whole grinding temperature satisfies law of conversation of energy, so the heat of grinding temperature field conducts equation to be: PCq-(kxq)-(kyq)-(kzq)-rQ=0txxyyzz(is inside W) among them W is whole region, it is comprised by 3 kinds of attrib border conditions, namely: Q=q(L, t)(is on L1 border) Kxqnx+kyqny+kzq Nz=qxyz(is on G2 border) Kxqnx+kyqny+kzq Nz=a(qa -q)xyz(is on G3 border) according to limited unit the disperse of the law changes a principle, differentiate workpiece into finite unit, what increase the hot load in grinding process on border is unit, it is disperse of integral temperature load namely as equivalent as real load node load, those who take the place of to be able to get grinding temperature field into 3 kinds of afore-mentioned attrib border conditions is finite yuan of model. The function of the W of territory of airspace of since of field function temperature of grinding temperature field, it is the function of time-domain T. In emulation model, use the method of circular iteration, it is the disperse of to load process of hot load finite a cutty process (the) that thinks in single course time-domain and dimensional territory are coupling. Grind in order to work for exemple, in cutty time to load of area of immanent some grinding secures thermal current, falling for a short while paragraph inside move to secure heat source to another area to load, and last time the initiative condition that the computation of earning regards this second analysis as as a result, inside time of this one cutty, think field function temperature and time and space are concerned, but both not coupling, the mathematical model that the method that can use partial disperse so reachs place shows grinding temperature field as follows: In type: R -- material density C -- T of material specific heat -- time Kx, ky, kz -- material edge X, y, the heat of Z direction conducts coefficient Q -- on G1 border give temperature, q=q(G, t) Q -- on G2 border give heat flow, q=q(G, t) A -- Qa of coefficient of convection heat exchange -- fall in natural convection condition, for outside ambient temperature; Forcing convection condition to fall, for the adiabatic wall temperature of attrib border layer. Qa=qa(l, the type on T) mixes time-domain of dimensional territory slant differential equation problem is N in the disperse inside dimensional territory the initial value problem that node divides equation for the Chang Wei of temperature Q(t) . Seek solution this N linear Chang Wei divides equation, get node temperature embattle, can reach the temperature of whole workpiece distributings. This formula is applied to dry grind and wet grinding two kinds of circumstances. The emulation process of field of 3 grinding temperature and result are with field of planar grinding temperature exemple, build the emulation model of grinding temperature field. If the graph is shown 1 times, hypothesis grinding contacts arc area to be ABBA, ≈ of L of length of face heat source (Dsap)½ and parallel moves at workpiece direction. Graph sketch map of heat source of face of 1 workpiece face pursues the emulation process sketch map of field of 3 grinding temperature pursues the sketch map of 2 grinding temperature field that do work of the TC4 when grinding pursue different deepness place works below 4 surfaces layer grind and wet grinding is emulated with test result input each grinding quite treatment, the operation that carries emulation model reachs the three-dimensional isotherm of grinding temperature field pursues finally. Will output the change of temperature field quite through changing the size of each parameter, can know the parameter change effect to temperature field clearly. It is in order to do work of alloy of titanium of TC4 of material of type grinding difficult treatment exemple, grinding dosage is as follows: Ns= 143r/min of emery wheel rotate speed, ds=245 of emery wheel diameter.

2mm, vs=18 of emery wheel speed.

46m/ S, workpiece speed Vw=14m/min=23.

33cm/s, grinding deepness Ap=0.

01mm, infeed grinding. L=170mm of B=10mm of test specimen width, length. Average and tangential grinding force Ft=66.

001N. The temperature field sketch map of this workpiece is shown 2 times like the graph. Same, in to load can get after the attrib border condition of convection heat exchange wet the sketch map of grinding temperature field, course and photograph of actual measurement temperature are compared, the error is in 10% less than. Graph the 3 emulation process sketch map that are grinding temperature field, the plan differs below the 4 facing that it is a watch deepness place is dry grind and wet grinding is emulated with test result quite. By the graph 4 can see, below same grinding condition, dry grind the highest temperature with wet grinding to differ very big (be in commonly 200 ~ between 300 ℃ ) , especially gradient of temperature of workpiece surface layer is bigger, dry when grinding cause burn extremely easily, and the temperature when wet grinding far the burn temperature under workpiece. Apply emulation model earning to analyse result and actual measurement value to differ not quite, the error is in 10% less than (result of emulation analysis earnings makes an appointment with tall 10%) than actual measurement value. Because measure itself of lukewarm test specimen to have an error,this is, and actual measurement temperature is to be apart from the temperature value that certain deepness leaves workpiece surface layer, so result of emulation analysis earnings approachs work more actual temperature value. 4 conclusion are in the research of grinding temperature field, applied computer emulation technology reachs integral grinding temperature distributings well and truly graph, decreased to use the error that test instrument place brings thereby, earning isotherm pursues more handy and intuitionistic. In the meantime, as a result of the complexity of grinding temperature field, introduce emulation model more analyse the effect of different treatment parameter to temperature of grinding arc area easily, discover the metabolic law of grinding temperature field thereby. Applied emulation technology still can be opposite grinding temperature field undertakes optimizing: Below the condition that machines parameter in the change, make the temperature of grinding temperature field changes incline to at reasonable, reduce the generation of grinding burn thereby. The computer of grinding temperature field emulates a technology to apply to all sorts of current and popular efficient grinding technologies not only, the emulation that also is grinding whole process at the same time laid very good foundation. CNC Milling