1、 l :2000-08-16; :2000-12-04 “ :S S / “ (98J18.2.2.HK0118) c :http:/ c I | : 1000-6893(2001)05-0424-05C , q e F Z E , | A( t bt ? v 1 , 100083)APPROACHES TOIMPROVE THE PROCESS QUALITYOF THIN-WALLED WORKPIECE IN NCMACHININGZHENG Lian-yu, WANG Shu-chun(Schoolof MechanicalEngineering andAutomation, Beij
2、ing Universityof Aeronautics andAstronautics, Beijing100083, China)K 1 : 4 Y V e F - _ ( + _ _ )s h l q M e ! 9 V S T ,| q j 8 , E L = F ,y ,Y V K s _ M 4 bi N ,G Q | a a C Z a 4 ,h l h “ F M ,r “ S b C g Y V _ r b1 o M : ; e F ; C , q ; M ; _ m s | :V260 D S M :AAbstract: Thispaper proposesa proced
3、ure diagram for NC planning/programming to analyzeanddecreasede-formation through preventive simulation, whichviewsthe workpiece asanelastic body withdeformation, es-tablishes the mechanical and technological model involving the real process constraints(such as locating andsupporting) andloads(cutti
4、ng, clamping and supporting forces), and checks the micro-errors(deformation)through the FEA(Finite Element Analysis) of the workpiece. In order to decrease deformation, this paperpresents four different improvement approaches or techniques. By consequently utilizing all these four ap-proaches accor
5、ding to the process quality cost trends, the optimization process environment which leads tohigher machining quality can begradually achievedprior to actualmachining. Finally, thispaper describesanexperimental study about an aerospace thin-walledframe to validatethe proposeddiagram andfour approach-
6、es.Key words: process quality; numericalcontrol; thin-walledworkpiece; deformation; spring-back; simulation e F V V s 3 : ! 9 , q I (F - ); L F S e (F );_ ) (F )bF “ d s , F M a q a a a s M , A Y F b C, q ,l 5 M e b “ - 1 L 2 $ | n , L H _ aF m u a9 F M , b3 , e F , - ! 9 I F ( / ) 1 o , 1 n CAE _ /
7、 , E F V “ d + + + ,V 7 Z b e F _ + _ _ 1b - | q a a 5 “ d 1 j 8 , I n “ d M ,Y V _ a V M 4 ,/ X b7 _ | q a j 8 , E ,y ,YV K s _ M 4 b N j1j6, M , “ - v K M ( )s e 1,3,4, jq 8 , nullap, i E I n M r , yM d (ap, i)M M d M ,V 7 3 M by N , M l,M r V 9 , b M v,M r A I n , ? s b(5) Pi(i= 1,2,l,n), b426 t
8、b 22 2. 3C Z T (1) , M F| M Ub C Z M 1 # 2 Z :C “ a ( C ) vl; ( ) “ a vlb B y M q M M ,y N C Z n :(1) M C ( ) “ | “ C ( ) s C ( ),E M Vv,h lC M i P q M ( b(2) M C ( ) | C T z V ,| T V b(3) M C ( )vl C a “ f / , V ? l C , 1 ? q C V b2. 4 q T (1) V , q s M f / , F M ,Y V M q K | M Ub 8 n q 9 F j F ,V
9、7 9 F q ,h l q M b H , V B Z E , m 1 U ? p , 5 Z E bm 6 , q mFig.6Smaple workpiece3 L m 6 f / ? g , q , LF6R, jv,C (2j3mm), v C M , q b F 9 8 :5 = 8 ,5 jb q ,F H + Y M , s a aC # C y Y ,y N 1 Q Q k M a a , , O F , b , q ! 9 _ k ,4 F B Q , 4 V Z E r b g / F ( ) b3. 1 k H q/ 486mm,C 3+ 0.3mm, 0. 2mmb
10、YCM-90HVA U S e 5 ,C Z j(N H j F , ) , = 8 j C bF Z T E (Trajectory Milling), null 20mm o h , n = 500r/min, M d ap =1mm, M d z ae = 50mm, S f =100mm/minb q Pro/Engineer“ CAD/CAM q ( m 1)b3. 2 k V T 4 M , ( ! 11 e P1,P2,lP11b I , C (P6),y N ) K ,F M K vb ! 9 1 p , _ “ S K vM V 0.3mmb_ k Z n V 1bZ 1 1
11、00mm/min, ! M “ 0.5( ), W j C ,C 400N, q M ( 9 F F )b M d T 7, 3.1 9 Md 291Nb H q y ,9 C K vM 0.708mm, v0. 3mmb , V e ) K vM (n m 7)b N , / V bV 1_ k Z Table 1Process alternatives for simulation Z | f /(mmcmin- 1) CZ q null, nullj /) ,x/N /H , j/(mmmm)K vM /mm1 100, - 2,400 0 0.7082 100/60/100 - 2,4
12、00 0 0.5373 100/60/100 0.5,0.2 2,400 0 0.3374 100/60/100 - 5,400 0 0.4715 100/60/100 - 5,400 2,2030 0.157(1) e F m 7, n 5 E , Z 2,| S Z 100(P1jP3),60(P3jP9)/100(P9jP11),H | P3 P9, M 1 o u (P3jP9) h l427 5 :C , q e F Z Em 7 1 V # TFig.7The first improvement processand results60mm/min, H q M ,9 M , C
13、K vM 0.537mm, q 24.2%b , B h lM , ( E n 2. 2 ), Z 3(null=0. 5, null= 0.2), T (2)9 e b x z _ M y _ M 1 l,y N V x z _ , y _ M , T m 7,K vM 0. 337mm, ? 1 p b(2) (1) M 1 , $ , ,7 C Z q , G Q Z 2,4 5b m 8,Z 2 T , B h lM , Z 4, q C Z , | W 2 j C 6 j C ,C M b , 9 M (m 8Z 4), C K vM 0.471mm, q 12.3%b7m 8 2
14、V # TFig.8The second improvement process andresults e P2 P3 ) # P9 P10) M 9 F , y ) “ 2j C ,C M 1 vbN H ,M r “ S ,y N B Z 5, q , q 9F F , j20mm30mm, Hq M , 9 M (m 8 Z 5), C K vM 0. 157mm, ? 1 p b m 8 V A , q ( 9 )r T K z , q r 66.6%b4 (1)C , q e F 1 o 5 F M e , F - V _ / e , h l h “ 1 M b(2) e V S T
15、 ? p ,8 a aC Z q Z E , V h lF M , b(3) q _ , ? .d F G a o Z , L =F H Z , ? r h F L Q ,vvh , / b I D1Suh S H, Cho J H, Hascoet JY. Incorporation of tool de-flection in tool path computation: simulation and analysisJ. Journal of Manufacturing Systems, 1996, 15(3):190- 199. 2Schulz H, Bimschas K. Optim
16、ization of precision machin-ing by simulation of the cutting processJ. Annals of theCIRP, 1993,42(1):55- 58.3Mounayri H E, Spence A D, Elbestawi M A. Milling pro-cess simulation- a generic solid modeller based paradigm J. ASME Journal of Manufacturing Science and Engi-neering, 1998,120(5):213- 221.4
17、Leu M C, Lu F, Blackmore D. Simulation of NC machin-ing with cutter deflection by modelling deformedswept vol-umesJ. Annals of the CIRP, 1998,47(1):441- 446.5Lim E M, Menq Chia-Hsiang. Integratedplanning for pre-cision machining of complex surfaces - part I:cutting pathandfeedrate optimizationJ. Int
18、 J Mach Tools Manufact,1997,37(1):61- 75.6Tsai J S, Liao C L. Finite-element modeling of static sur-face errors in the peripheral milling of thin-walled work-pieces J. J of Materials Processing Technology, 1999,94:235- 246.7f 2 3 . F ! 9 m M. :t b ,1987.471- 475.T e : n ut b v 2001 M 2 (3 I : )428 t b 22
