International Industrial Informatics and Computer Engineering Conference (IIICEC 2015)

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1 Interntionl Industril Informtis nd Computer Engineering Conferene (IIICEC 5) Simultion Implementtion nd Applition Reserh of High Speed Milling Regenertion ype Chtter Bsed on MALAB Yun Lingling, Mei Wentob, Zheng Yongfeng injin Bohi Votionl ehnil College, injin, Chin Keywords: Chtter stbility domin; Mhining proess simultion; Milling Abstrt. Considering the defiieny in milling proess prmeters seletion in the domesti. Bsed on the modeling of dynmi milling fore nd the lulte of htter stbility limits. Relizing high speed milling regenertion type htter simultion lgorithm with Mtlb development tools. hrough the modl hmmer experiment, Obtining the frequeny response funtion to simulte the htter stbility domin grphis of the whole proessing system whih n be used s n instrution guide for the seletion of milling proess prmeters. he vlidtion nd ury of the simultion lgorithm ws verified by experiments nd used in ftory with n exellent pplition effet. Introdution At present, the hrdwre ondition nd prodution performne of high preision nd high speed is provided by dvned high speed milling mhining enter of domesti nd foreign in theory, but these devies filed to ply mximum proessing pity, the reson is tht the relevnt problems of mehnil vibrtion in tul prodution Mhining proess. he prodution prties show tht the slight htter leds to the qulity deline of the mhined surfe, reduing the prodution effiieny, Bering overlod nd shortening the life of min shft. Hevy htter leds to serious brekge of the utter nd dmge of work piee nd spindle. herefore, the reserh of uses, rules nd suppression methods in high speed milling htter n effetively void the instbility used by vibrtion[-6]. this pper estblishes regenertive type stbility domin simultion flow hrt of high speed milling nd through the Mtlb simultion lgorithm for the nlysis [7-9]. Seleting the stbility prmeters in order to void htter, the simultion method hs been pplied in the ftory nd obtined the good pplition effet. Chtter heory of High Speed Milling he Dynmi Model of Milling Fore In High Speed Milling. he stti milling fore model without onsidering the effet of dynmi hrteristi prmeters in high speed milling, the utting thikness of milling proess ws simply onsidered nonliner reltionship between feed rte nd the instntneous ngle, ignoring the influene of vibrtion in milling proess. herefore, when the milling prmeters hnge or workpiee vibrtion, the stti milling fore model n not desript bout the true milling proess, dynmis modeling hs beome n inevitble trend. he most ritil for the dynmis modeling is the dynmi utting thikness model, shown in Figure, expressed s: hd (f j ) = f t sin f j + (u j u j ) (u jw u jw ) he milling dynmi system is simplified s Spring dmping mss model in vibrtion mehnis, onsidering the influene of the previous utter tooth left by orrugted surfe, Instntneous rigid fore model is used in utting tool, the influene of stti deformtion fore is negleted. he Dynmi milling fore is obtined by umulting lgorithm. In the time domin model, milling fore model for differentil forms expressed s follows: 5. he uthors - Published by Atlntis Press 3

2 = p t () { F( t) } K [ A( t)] { ( t) } In the formul A() is periodi funtion of ω=nω, =π/ω. his formul is deomposed ording to Fourier series will simplify the lultion mode. Budk nd Altints[, ] hve been proved the effet of periodi funtion hrmonis on foresting preision n be negleted in prtil pplition. So fter the time-vrying system is trnsformed by Fourier series, only the first term is reserved. he formul is s follows: φex N xy [ A()] = [ A( φ)] dφ = φ φst p p yx (3) he simplified milling fore oeffiient introdues into dynmi milling fore formul, further simplified s: { F( t) } = K [ A ]{ ( t) } p t (4) Fig. Shemti digrm of the dynmi utting thikness he Chtter Stbility Domin Algorithm. In the milling htter stbility nlysis, Only onsidering the effets of dynmi milling fore produed by the dynmi displement of the tool nd workpiee; he stti prt of the milling thikness is negleted.he min reson for the utting depth nd utting diretion hnges is the periodi hnge of dynmi milling fore oeffiient mtrix. hen the frequeny response funtion of the tool nd the workpiee is expressed s the following form: G G x( s) ( s) = = F ( s) k x y( s) ( s) = = F ( s) k y x ( s y ( s ωnx + ζω s + ω ) ω ny nx + ζω s + ω ) ny nx ny (5) In the frequeny domin nlysis, the vibrtion vetor eqution desribed by hrmoni funtion, nd the eqution is trnsformed into frequeny domin eqution, the trnsformtion regenertion displement eqution s follows: t { r( )} { r )} = [ e ] e [ G( )] { } { ( )} = F (6) 33

3 he eqution 4 is substituted into the frequeny domin dynmi milling fore model of 6, Dynmi milling fore onsidered the regenertive vibrtion is shown s follows: { F} e t t = pkt( e )[ A ][ G( )]{ ( t)}{ F} e (7) In the htter frequeny, the mthemtil formul is estblished on the flutter stbility nlysis of losed loop feedbk dynmi milling system. lso lled the hrteristi eqution, the Relted eqution nd solution As follows: N det[ I] pkt ( e ) [ G )] = p Λ = ( ± 4 ) (8) (9) Among: = G = G ) G ) + G )( ) ) xy yx () Aording to Euler's formul, onsidering the tul prodution nd proessing xil bk enggement is rel, Clulting system n stedy utting under the htter frequeny w nd the ritil ondition of the xil bk enggement plurl form is expressed s follows: plim p Λ = [ NK t R ( osω ) + Λ osω I sinω Λ + i I ( osω ) + Λ osω R sinω ] () In the tul prodution of milling p must be rel, herefore imginry prt of type must be zero. hen simplified Limit formul of xil bk enggement n be obtined s follows. p lim p Λ R[ + κ ] = NK t () Under the utter tooth utting yle of is known, We n solve the spindle speed relte to ritil xil bk enggement, expression is s follows: = ( ξ + kπ ) n = ω 6 N, n 6 N[(k + ) π tn = ( Λ I / Λ R ) ] (3) In the formul, K represents lef number of the flutter stbility nlysis grphs. After the bove nlysis, the ultimte expression of high speed milling htter stbility ws obtined, Proessing system dynmis prmeters re obtined by using experimentl modl nlysis method (Hmmering experiment), ht is FRFs of the tip or the workpiee mhining prts. Simultion Progrm Design. Bsed on the bove theoretil nlysis, he simultion progrm ws developed bsed on softwre MALAB7., the simultion interfe is designed bsed on MALABGUIDE integrted environment (Grphil User Interfe development environment) ACCESS Dtbse nd Visio Bsi.he simultion results re output in the form of grphi nd dt files. he progrm blok digrm of the whole is shown in Figure, the simultion results of flutter stbility region is shown in figure 3. With the similr foreign softwre suh s CUPRO ontrst, wo simultion results re bsilly the sme, but fster simultion speed. 34

4 Experimentl verifition In order to verify the vlidity nd ury of htter stbility domin simultion lgorithm, utting experiment ws rried out in the FIDIA D38 high speed mhining enter. he mximum speed of mhine tool is 3r/min. ool used by the experiment is the whole hrd lloy utter of Sndvik, Prmeters: dimeter of mm, teeth, 3 spirl ngle, instll overhng length is 7mm. he workpiee mteril is luminum lloy AL, speimen size is (mm). Hmmer test ws onduted bsed on the "mhine - tool" system. he X, Y diretion of the FRFs is obtined. Compred with the tool, the box workpiee is onsidered rigid body nd it n be negleted when the simultion. Fig.3 is the htter stbility lobes digrm of domin simultion. Vlidtion experiments were performed in 6 seleted points from the digrm ( sid flutter, sid the stble utting zones). ble is the proessing prmeters used in the experiment nd verifition results. Fig.3 nd tble shows, flutter does not pper when the,, 3 points utting prmeters were used. While flutter ppered when the 4, 5, 6 points utting prmeters were used. his is fully onsistent with the flutter stbility domin simultion results. herefore the flutter stbility domin simultion lgorithm is proved to be effetive nd ury. strt Input the tool geometry, utting fore oeffiient, FRF proessing system, utting prmeters nd simultion prmeters K= he elertion of FRF is onverted into the displement lultion of FRF: xy yx ω = ω min ω = ω min he spindle speed nd the ritil xil depth of ut orresponding Adjent to the htter frequeny re liner interpoltion. he minimum ritil xil eh speed utting depth is preserved. Clult the FRF vlue Clulte the Eigenvlue of hrteristi eqution Clultes the eigenvlues orresponding to the spindle speed, xil depth of ut nd the hrmoni speed limit ω = ω + ω = ω mx No ω = ω + Yes K=K+ N K=Lef Number Output: he htter stbility of grphis nd Dt files ω = ω mx No End Yes Fig. he htter stbility lobes digrm 35

5 Applition nlysis Fig.3 he simultion results he front of the milling htter stbility domin simultion method hs been pplied nd good results were obtined in lrge stte-owned enterprise. Now in the enterprise bkbone mhining enter FIDIA D58 is tken s the exmple to illustrte. he mximum speed of FIDIA D58 is 4r/min, the utting prmeters of previously used fr less thn this vlue (empirilly seleted). Dynmi prmeter test nd flutter stbility domin simultion is rried on severl tools, through the simultion experiment utting prmeters re optimized seletion. he utting prmeters nd the mteril removl rte omprison before nd fter optimiztion is shown in ble. Apprently, ording to the simultion results of htter stbility lobes Cutting prmeters re hoose more resonble, the proessing effiieny is higher. ble he flutter stbility domin verifition (ll slot milling, feed per tooth for.mm) Number Spindle Speed (r/min) he Critil ut depth(mm) Cutting Voie Norml Srem Norml Srem Norml Noise Workpiee surfe topogrphy he tool prmeters Φmm/ooth Φmm/ooth Φ5m/ooth Φ5mm/4ooth Conlusions nd disussions Conlusion Stble Flutter Stble Flutter Stble Flutter ble he optimiztion of utting prmeters tble before nd fter Spindle speed Rdil utting depth Axil utting depth he mteril removl rte (r/min) (mm) (mm) (m 3 /min) In this pper in order to solve the problem tht selets the prmeters existing CNC milling 36

6 proess, bsed on Clultion nd nlysis of the dynmi milling fore modeling nd flutter stbility region, king Mtlb s the development tool,estblishing the regenertion Chtter milling simultion lgorithm. he priniple nd steps of the lgorithm re presented in detil. he flutter stbility domin grphis of the whole mhining system ws given out, Beuse of these theories nd lgorithms, the seletion nd optimiztion of milling prmeters is provided theoretil bsis. he simultion lgorithm is proved to be effiient nd urte by utting experiment, nd in the plnt prtil pplition reflet its prtil vlue. Referenes [] J Grdisek, M Klvem nd K Weinert : Int J Mh ools Mnuf Vol. 4-44(4), p.44 [] S Rthev, S Liu nd W Hung, et l: Mter proess ehnol Vol (4), p.53 [3] S H Ryu, C N Chu: Int J Mh ools Mnuf Vol (4), p.44 [4] B A Msrdelli, S S Prk nd Freiheit : Journl of Mnufturing Siene nd Engineering Vol.-(8), p.3 [5] Z Lei, Z Li: Interntionl Journl of Mhine ools&mnufture Vol. 5-35(4), p.44 [6] Z Z Li, Z.H Zhng nd L Zheng: Interntionl Journl of Advned Mnufturing ehnology Vol (4), p.4 [7] U Brvo, O Altuzrr : Interntionl Journl of Mhine ools&mnufture Vol (5), p.45 [8] V Ggnol, B C Bouzgrrou : Interntionl Journl of Mhine ools&mnufture Vol (7), p.47 [9] E Ozlu, E Budk : Journl of Mnufturing Siene nd Engineering Vol, 76-73(7), p.9 [] Y Altints, E Shmoto nd P Lee, et l: Journl of Mnufturing Siene nd Engineering Vol (999), p. [] E Budk, Y Altints nd E.J.A Armrego : rnstions of the ASME Journl of Mnufturing Siene nd Engineering Vol. 6-4(996), p. 8 37