ISSN: 2354-0575 ,^=" •f" [SI i \ '^ / '•'^^^ NGHIEN ctru ANH Hl/OfNG CUA CAC T H N G SO C N G NGHE DEN DO NHAM BE MAT KHI GIA CONG TRiN MAY PHAY CNC THEO PHl/ONG PHAP THIET KETHlTC NGHIEM RESEARCH THE EFFECTS OF TECHNOLOGICAL PARAMETERS TO SURFACE ROUGHNESS IN PROCESSING THE CNC MILLING MACHINE BY DESIGN OF EXPERIMENTS METHOD Nguyen Trgng Hiing', Pham Vdn Tiian^ Truang Dgi hoc Suphgm Ky thugt Hung Yen Trudng Cao ddng nghe Co gi&i vd Thuy lgi Tomtit: Bdi bdo ndy trinh bdy phuang phdp nghiin ciru dnh huong eua ede yiu td cdng nghi din dp nhdm be mat gia cdng tren mdy phay CNC theo phuong phdp thiet ke thue nghiem (DOE), ldm gidm sd lugng thuc nghiem, tgo sdn phdm chdt lugng eao vai ehi phi thdp cho cdc nhd sdn xudt Ket qud nghien ciru cho quan he giira dd nhdm be mat vdi cdc thdng sd cdng ngh4 gdm van tdc edt, lugng chgy dao, chiiu sdu cat vd xdc dinh duge thdng sd cdng nghi tdi uu cue bp (trong phgm vi khdo sdt) cd dp nhdm be mat nhd nhdt gia cdng tren mdy phay CNC Do dd, ndng cao chdt lugng be mat vd ndng sudt gia cdng Ti^ khda: Anh hu&ng yiu td cdng nghi Do nhdm bi mat gia cdng, Thiit ki thuc nghiim Ma trgn tritrc giao Vdn lde cat Lupng chgy dao vd Chiiu sdu cat Mdy phay CNC Md dau Viec nghien cuu anh huflng eac thflng sfl cflng nghe den dp nham be mat gia cong tren may phay CNC, theo phuang phap thilt kl thue nghiem (DOE) sir dyng ma tran true giao cap I, dl dam bao nham bl mat nhfl nhat (dp bdng cap nhdt) va xdy dyng mfli quan he giua dp nham bl mat vdi cac thflng sfl cflng nghe gom van tflc cat, lugng chay dao va chieu sau eat, dieu kiln san xuat hang loat theo phuang phap dilu chinh san tren may phay CNC Do dfl, nang cao chdt lugng lam vile cua cac chi tilt may, dac biet la eae ehi tiit may tham gia vao mfli lap ghep va nang suit gia eflng Theo phuang phap nay, hien dang dugc ling dyng nghien ciru d nude ngoai va hien cae eflng trinh chua nghiin cim mgt cdch ddy du ve van de ITnh vyc che tao may (vi dy, moi chi dimg lai d vile su dung phuang phap hfli quy ham so rati, hoac nghiin ciiu dnh huong theo timg biln riing re va chua xet din cac he so tuang tac) Qua nghien eiiu nit nhiing vdn de cd tinh quy luat, kilm ehiing tren thyc te Tir d6, xay dung thu vien che dfl cflng nghe gia eflng cho qua h'inh san xuat tuang tu, giiip cho nguoi thao tac dl dang ling dyng, nham tfli uu cac thflng sfl cflng nghe pham vi khao sat Cu sd phu-ong phdp nghien cihi theo thiet ke thuc nghif m (DOE) Phuong phap quy hoach thyc nghiem la rapt nhirng phuong phap diiit ki thye nghiera {DOE) dang dugc img dyng linh vyc ehi tao may [2] 12 Khoa hgc & Cong nghe - So 3/2014 Phuong trinh hfli quy {md hinh todn hpc) nhan dupe bang phuang phap quy hoaeh thyc nghiem cfl the dung de xae dinh eac thflng sfl dau vao toi uu mudn dat thflng sfl ddu eye tri (\dn nhdt hodc nhd nhdt) 2.1 Phuwng phap quy hoach su di^ng ma triin true giao Theo phuong phap nay, cap ciia ma tran true giao phy thudc vao bae eua biln sfl khao sat, nfl co dang cap I bien so la bac nhat va cap bien sfl Idbeichai - Mien bien thien: Z"'" < Zj < Zj""" - Tdm quy hoaeh: Zj" = 0.5(Z,'™ + Z,'™) - Phuang phdp phan tich hfli quy: Cac phuang phdp phan tieh hfli quy gflm cfl Phuong phdp binh phuong nhd nhdt: Hdi quy tuyin tinh mdt biin; Hdi quyparabol; Hoi quy hdm sd mu vd Hdi quy nhiiu bien Chd y rdng, su dgng hdm nhiku biin tdng qudt vd cho ket qud v&i dp chinh xac cao han Khi tiln hanh quy hoach sd dyng ma tran tryc giao cipl vdi ba thdng sfl nghien cdu, ham hfli quy nhilu bien cfl dang nhu sau: y = fio + h\X\ + b2X2 + &3X3 + 612X13:2 + + 1)23X2X3 + 6133:13:3 + bi23 X{.X2.Xi Trong dfl: x^- Biln khao sat bae dj,-He sfl hfli qui Journal of Science and Technolosv ISSN: 2354-0575 b^ - H I sfl tuyin tinh 6,.' 6, ( - H I sfl tuong tdc cap vd tuong tdc ba - Thgc hien N = 2*^ thi nghigm, roi tmh toan cac h | sfl hfli quy b bing phuong phap binh phuong nhfl nhat - Kiim djnh sy cfl y nghia cua cac he sfl hoi quy b theo tieu ehuan Student, bang each thyc hien cac thi nghiem tai tam quy hoach hoac su dyng cac thi nghiem song song, lap lai Loai bo ede he sfl b khong CO nghia, tinh toan I91 eac b va kiem dinh lai cho tdi chi cdn cac b co nghia - Kiem djtih sy cfl nghia cua phuang trinh hfli quy voi chudn Fisher 2.2 Thm: nghidm y i u to toan phan N = l"" - Phuong phdp tfl chue thi nghiem tryc giao cap I: + Sfl thi n g h i | m can thye hien: N = 2'' + Muc ea ban {tdm phucmg dn): ^j Trong do: ^mex _ ^Q ^ ^^ ^^f, ij.g|, (miic eao), ^min ^ 2y — /I: Mue dudi (muc thap); ^, = —^—^—-—: Khoang biin thiin theo true Z - Biin khflng thii nguyen x^: Ma hod duae thyc hien nhd vile chgn tam Z° ciia miin nghien ciiu lam gflc he true tga dfl ' Xdy dung bai toan nghien cuu va thuc nghiem 3.1 Bai todn nghiin cuu Nghien cim anh budng cua chi dfl cflng nghe den nham be mat cua loat ehi tiit gia cong thu tren may phay CNC thay dfli che dp cflng nghe: Van tflc cat V (vg/ph), Lugng chay dao S (mra/vg) va Chilu sau cat ((mm) 3.2 Lua chgn gid tri cdc thdng s^ cong nghe Vi|c lya chpn cae thflng sfl cflng nghe phy thupc vao phuang phap gia cong, thiet bj, dung cy cat, vat lieu lam dao, vat lieu duoc gia cong va efl thi dupe tra cuu tu tdi lieu [5], [6] Dieu kien thuc nghiem • - Su dung mdy phay true CA'C - DMC635V Hang DECKEL MAHO Cflng Hoa Lien Bang Ddc che t^o, he dieu hanh FANUC32i - Dao phay mat diu SESCO R220.43-005A, lam bang hgp kim, sfl rang z = - Vat lieu phfli' thep cacbon C45 - Chi tiit gia cong cfl dang be mat phang (hinh I) Tu cac tai lieu [5], [6], [7] va [8], voi myc dich nham b i mat ciia mau thu nghiera nhfl {do bdng cao) thyc nghiera d day lya ehgn cac thong so eflng nghe gflra van toc cat (V), lugng chay dao (S) va chiiu sau cit (t) theo eac so lieu bang Bang Thong s6 cdng nghf zr-z' _zr'Z° ~ Trong do: - HI so thuy phuong trinh hdi qui 5j - Sai lech binh phuong trung binh ciia he sfly y = I , , ,k Al _Zl-yZl - Xdy dung ma tran thue nghiera: + Sfl thi nghiem xac dinb theo eflng thirc N = 2'', c5t Xg lufln bdng + Lap eho timg y i u tfl anh hudng va lan lugt hi JT; dinjc^; + Dua cac thi nghiem d tara vao raa tran I Muc cao Muc trung binh Muc thap V (m/min) S (mm/vong) t (mm) 81 0.45 1,0 71 0.3 0,6 61 0.15 0.2 2.3 "i nghia cua h i so b phirong trinh hoi Tinh y nghia ciia eac he so b dugc kilm dinh theo chuin Student (t) xac djnh nhu sau: '' M 5., Khoa hpc & Cong ngh? - S6 3/2014 Hinh Bi mat mdu sau phay tinh Journal of Science and Technology 13 ISSN: 2354-0575 - Khodng bien thiin: Xi=lOra/ph;AJ =0.15 mm/vong;/I; = 3.3 Thiet ke thuc nghiem 3.3.1 Thiit ke thuc nghiim nghiin cuu anh hudng eiia thong so cong nghe den dg nhdm be mat a Phuong phdp td chuc thuc nghiem true giao cdp I - Sd thuc nghiem: mm - Cdc biin Ichdng thu nguyin: + Bien khflng thd nguyen v | n toc: ij™ — 1; i j " " =— ; Xj" = + Biln khflng thd nguyen lupng chay dao x^"" = I ; Xj~° = 1; xf -0 Sfl yiu tfl anh hudng den dp ehinh xac kich thudc gflm yeu tfl la van tflc eat, ehieu sau cat va b Ma trgn thuc nghif m luang chay dao Tir phuang trinh hfli quy lya ebon: k=3 - Chpn hara hfli quy cap I tuyen tinh cfl dang: So thyc nghiem tai tam: N^ = y - 6o + bixi + 623:2 + ^3X3 + 612X1X2 + Suy ra, tflng sfl cugc thyc nghiim: NE = N , + N , , - + = + 623X2X3 + &13X! 3:3 + 6123 Xl X2.3:3 - Mirc CO bdn • Trong do: u day chon: 6g - h | sfl hfli qui V^^^ = 6! m/ph; S^^^ = 0,15 mm/vong; t^^^ b - h i sfl tuyen tinh 0,2 mm.'"' b^.' 6,, - he so tuong tac cap va tuong tac ba Suy ra, ma tran thi nghiem vdi k = vd F ^ = 81 m/ph; 5"^^ = 0,45 mm/vong; t^ = thue nghiera tai tam phuang dn vdi cac thong sfl ddu 1,0 mm vao {V S t) va cac bien raa hfla l a ^ ^ X^ X.^ vaX^ Suy ra: Vj = 71 m/ph; ^ j = 0.3 mm/vong; dupe chi dan tren bang t, - 0.6 mm TT X, X, X, X, x,.x x,.x, x,.x, x,.x,.x, ! 10 11 12 -1 -1 -1 0 0 0 0 0 0 0 0 0 Trong do: X^ - biln ao dupe dua thera vao ma tran; X^ - bien ma hoa img vdi van tflc cat, X.^ - biln ma boa img vdi lugng chay dao X.^ ' biln ma boa img vdi chieu sau cat -1 -1 -1 -1 0 0 -1 0 0 V 61 81 61 81 61 81 61 81 71 71 71 71 S 0.15 0.15 45 0.45 0.15 0.15 0.45 0.45 0.3 0.3 0.3 0.3 t 0.2 0.2 0.2 02 1.0 1.0 1.0 1.0 1.0 0.6 0.6 0.6 + Dp phan giai 0,000I25pm 3.3.2 Lua chgn phuong phap va thiet bj - Phuang phap do: nham b i mat theo phucmg phdp dau dfl - Thiet bl (hinh 2): + May nham be mat Mitutoyo SJ-4Q0, cfl bfl phan ghi kit qua ciia Hang Mitutoyo (Nhat Hinh Do nhdm mdu trin mdy Mitutoyo 14 Khoa hoc & Cong nghe - So 3/2014 SJ-400 Journal of Science and Technology ISSN: 2354-0575 - Ket qua gia tri nhdm 12 mau doi vdi mfli phuang an ciia 12 cuflc thi nghiem theo ma tran thyc nghiem duge chi ddn trin bdng TT Gia In (Cupc Gia tri nhlim Gia hi Giatn Ihi nghiem) (nm) Gia tri Gia hi Giatn Giam mau mlu mlu y,! y,4 (nm) y.s (nm) (nm) (nm) (nm) (nm) (nm) (nm) y,2 y.6 y, y,7 y,» 10 11 12 y.io y.ii y,i2 Gia tri trung binh (nm) (nm) (nm) nham (nm) 0,156 0,342 0,145 0,136 0,198 0,341 0,159 0,169 0,259 0,170 0,142 0,130 0,195 0,184 0,168 0,166 0,168 0,170 0,168 0,169 0,168 0,169 0,169 0,170 0,170 0,169 0,192 0,193 0,197 0,193 0,216 0,192 0,237 0,227 0,229 0,228 0,230 0,238 0,214 0,204 0,187 0,195 0,160 0,231 0,203 0,194 0,156 0,159 0,147 0,169 0,144 0,179 0,318 0,202 0,299 0,195 0,435 0,591 0,289 0,574 0,427 0,389 0,478 0,570 0,397 0,210 0,223 0,232 0,418 0,345 0,397 0,593 0,364 0,296 0,386 0,346 0,171 0,3317 0,338 0,344 0,511 0,555 0,552 0,579 0,752 0,850 0,920 0,464 0,437 0,606 0,575 0,134 0,268 0,294 0,281 0,537 0,542 0,537 0,530 0.524 0.626 0,631 0,623 0,460 0,297 0,198 0,240 0,292 0,195 0,305 0,495 0,429 0,457 0,359 0,259 0,392 0,3265 10 0,223 0,270 0,393 0,211 0,189 0,164 0,340 0,340 0,340 0,449 0,545 0,235 0,308 11 0,242 0,234 0,235 0,273 0,275 0,274 0,255 0,314 0,222 0,486 0,322 0,500 0,302 12 0,242 0,225 0,263 0,272 0,273 0,303 0,322 0,257 0,262 0,316 0,312 0,318 0,280 3.3.3 X u ly va kiem tra s6 lilu thuc nghifm - Vdi ham hfli quy cap I tuyen tinh da chpn CO dang: y = 6o + 6i Xl + 62X2 + 63X3 + 612X1X2 + + 623X2X3 + 613XL X3 + 6123 Xl.X2.Xi Suy ra, dang eua phuang trinh hfli quy can phuong trinh hfli qui theo phuang an thyc nghiem tai tam va y nghia cua cac he sfl b dugc kiem dinh theo chudn Student (t) Suy ra, cdc he sfl by by by by b efl y nghia vd deu dugc giii lai phuong trinh hoi quy Do dfl, Phuong trinh hfli quy cfl dang nhu sau: Y = 0,3114 - 0,0201 Xl + 0,0279 ;i"2 + tim: r - , ) + i Z , + X + 63 X^ + bn.Xi.X2 + ba X2.X3 + bu Xl X3 + 6123 • ^i + X2.X3 - Theo phuang phap binh phuang nhfl nhat, cac he sfl b phuong trinh hfli quy cua quy hoach tryc giao cdp I tuang img vdi k = yeu td anh huflng ed gia tri nhu sau: 60=0,3114 61—0,0201 bi = 0,0279 63-0,1111 612—0,0048 623 = 0,0231 613 = - , ,6123 = - , 0 Sau kilm tra y nghia cua eac he b K h o a hoc & Cong nghe - So 3/2014 + 0, n i l X3 - 0,0048 X1.X2 + 0,0231 X2 Xz + -0,01.Xi.X3-0,0034.Xi.X2 ^3 - Kiem tra sy tuong thich cua phuang trinh hfli quy vdi thyc nghiem theo bang gia tn gidi ban cua chi tiiu Fissher F Ft, Si 0,003440 ^0.180 Sih F(0,95)(f,,f,) = F(0,05)(6,3) - 5,3! F < F^^, phuang trinh hdi quy tim dugc la tuong thich vdi thyc nghiem vdi mdc y nghia 95% - Kiim tra su dflng nhdt eua eac phuong sai theo bang gia tn gidi han ciia chi tieu Cochoren Gtn = Zs,-: 0,, = 0,547 Suy ra, G,^ < G^ J o u r n a l of Science and Technology 15 ISSN: 2354-0575 3.3.4 Do thi thuc nghiim Trin hinh 3a, ede diem ma gia tri nham eiia Su dyng phdn mera Microsoft Excel - 2007 mdu thu dng vdi 12 phucmg an cflng nghe phy thuflc di tinh toan va phdn mem Tableeurve 3D V4.0.0 vao gia tri cua V \k S theo ma tran thyc nghi?m di ve biiu dfl quan he gma eac thflng so cflng nghe (bang 2) va gid tri ciia no tuong dng vdi cot gid tri din nham bi mat gia eflng tren may phay CNC trung binh cua nham bang va qua co nhan xet cu the ve mfli quan he todn Trin hinh 3b, ede dilm gia tri nhdm eiia mau hoc cua nfl Chu y rang, phan mem Tableeurve 3D thu nhd (ddng 2, 4, va - bang 3) phu thuoc vao V4.0.0.1 chi biiu dien dugc quan he giiia ba thong Kva / hrong ung voi bon phuang an cong nghe 2,4, sfl I va bang Do do, anh huflng cua cdc thflng sfl cflng Trin hinh 3c, cae dilm gid tri nham cua mdu nghe bao gflm van toc cat V, lugng chay dao S vd thli nho (dong 2, 4, va - bang 3) phu thugc vao chilu sau cat f den nham be mat ehi tilt gia cflng S vd t tuong img voi bon phuang an eong nghe 2,4, trinraayphay CA'C se dugc bieu tren cac hinh (3a, va bang b va c) - Anh hudng eiia van tflc cat va lugng chay dao den nhdm be m§t: %^ O.J ^.opW Hinh 3a Anh huang ciia Vvd S den nhdm be mat tuong ung voi 12 cugc thu nghiem - Anh huong cua van tflc eat va ehieu sau eat din nham be mat: Hinh 3b Anh hu&ng eiia Vvd I din nhdm be mat tucmg ting vdi 12 eudc thu nghiim Khoa hoc & Cong nghe - S6 3/2014 Journal of Science and Technolosy ISSN: 2354-0575 - Anh hudng cua lugng chay dao vd chiiu sdu edt din nhdm bi mat: Hinh 3c Anh huang ciia Svd t din nhdm bi mat luang img vai 12 cupc thic nghiem Kit qua thuc nghidm vd danh gid ket qua nghiin cuu Tu kit qua nghien euu thay rdng, che cflng nghe tdi tm cue bg {trong phgm vi khdo sdt) efl dfl nham be mat nhfl nhat {dp bdng cao nhdt) cae thflng sfl cong nghe dugc lya chgn: - Van tdc cat: V = 81 (m/phut); lugng ehay dao: S ^ 0,15 mm/vong (hinh 3a) - Van toe eat: V = 81 (m/phiit); chilu sau cat: t = 0,3 mm (hinh 3b) - Lugng chay dao: S = 0,15 mm/vong; chieu sdu cat: t = 0,3 mm (hinh 3c) Do dfl, theo phuang phap thiet ke thue nghiem {DOE) sit dung ham hfli quy nhieu biin, phuong trinh boi quy thu dugc cfl eae he sfl tuong tac cap va tuong tac ba ke den anh hudng ciia eae thflng sfl cflng nghe den nham be mat cht tiit gia cflng Day la dilm mfli va khac biet so vdi cdc cflng trinh nghien cim da cflng bo d va ngoai nudc Bfl thflng sfl cflng nghe tfli uu eye bg (trong phgm vi khdo sdt), nham bl mat cfl gia tri nhfl nhat {do bdng cao nhdt) nhu sau: V ^ 81 (m/phut); S = 0.15 mm/vong, t = 0.3 mm Tai lieu tham khao [I] Tran Van Dich, Nghien ciru dp chinh xdc gia cdng bdng thuc nghiem, NXB Khoa hgc va ky thuat, Ha Noi 2003 [2] Nguyen Trgng Himg, Thiit ki thuc nghiem chi tgo mdy, Truong Dai hgc Su pham ky thudt Hung Yen, Hung Yin 2013 [3] Pham Van Tudn, Nghien ciru dnh hu&ng cua che edng nghe den nhdm be mdt gia cdng trin mdy phay CNC, Luan van Thac sy ky thu|t, Truong Dai hgc Su pham ky thuat Hung Yen, Hung Yin 2013 [4] Ninh Due Tfln, Nguyin Trgng Hiing, iCyf/iuarifo Tdp I Dung sai lap ghep vd Tieu ehudn hda, NXB Giao due Viet Nam, Ha Npi, 2006 [5] Nguyin Ddc Lfle va cae tae gia, Sd tay Cdng nghe che tgo mdy, NXB KHKT, Ha Ndi 2000 [6] NTU, Tra ciru chi cat, Khoa Co khi, Truflng Dai hoc Nha Trang [7] LulzimBalal.AfrimGjelajI, Avdyl Bunjaku2 and AvdiSalihul,5«r/acei?o«gArt^sso/Matena; Processing during Milling Process, Joumal of Mechanics Engineering and Automation (2012) 601-605 [8] Nitin Agarwal, Surface Roughness Modeling with Machining Parameters (Speed, Feed & Depth of Cut) in CNC Milling, MIT IntemationalJoiunal of Mechanical Engineering, Vol 2, No lU, Jan 2012, pp (55-61) Khoa hoc & Cong nche - So 3/2014 Journal of Science and Technology 17 ISSN: 2354-0575 Abstract: This article presents a research method the effects of the technological parameters to surface roughness in processing the CNC milling machine by design of experiments (DOE) method, which reduces the number of experiments, produces high quality products with low cost for manufacturers Results of research for the relations between the surface roughness and technological parameters including cutting speed, feed intake ranging, depth of cut and determine the local optimum technological parameters (within the survey) with minimum surface roughness when processing on CNC milling machines Therefore, the the quality of surface and productivity in processing are improved Keywords: Effect factors of technology Surface roughness Design of experiments (DOE) Orthogonal array Cutting velocity Flow range and Depth of cut, CNC milling machine Nguoi phan biln: GS.TSKH Bdnh Tien Long 18 Khoa hoc & Cong nghe - S6 3/2014 Journal of Science and Technology ... qua gia tri nhdm 12 mau doi vdi mfli phuang an ciia 12 cuflc thi nghiem theo ma tran thyc nghiem duge chi ddn trin bdng TT Gia In (Cupc Gia tri nhlim Gia hi Giatn Ihi nghiem) (nm) Gia tri Gia. .. dng vdi cot gid tri din nham bi mat gia eflng tren may phay CNC trung binh cua nham bang va qua co nhan xet cu the ve mfli quan he todn Trin hinh 3b, ede dilm gia tri nhdm eiia mau hoc cua nfl... cuu Nghien cim anh budng cua chi dfl cflng nghe den nham be mat cua loat ehi tiit gia cong thu tren may phay CNC thay dfli che dp cflng nghe: Van tflc cat V (vg/ph), Lugng chay dao S (mra/vg)