^ANH HUONG CUA CHE DO CAT DEN TOPOGRAPHY BE MAT DA MAI
THE EFFECT OF CUTTING PARAMETERS ON TOPOGRAPHY OF GRINDING WHEEL SURFACE
ThS. Nguyen Van Thien', TS. Nguyen Huy N i n h \ GS,TS. Trin Van Dich- 'Trudng Dai hpe Cdng nghiep Ha Ndi
-Trudng Dai hpe Bach klioa Ha Ndi
TOM TAT
Bdi bdo ndy frinh 6ay nghien ciru dnh huang ciia chi do cdt din Topography bi mat da mat khi mdi phdng. Noi dung cua bdi cung trinh bdy phuang phdp nghiin cini bdng thuc nghiem vd xu ly sd lieu de dua ra mdi quan he giita chi do cat vai mdt sd thdng sd dgc trung ciia Topography. Tit dd lam ca sa cho viec nghien ciru vi Topography be mat cua dd mdi vd dnh huang ciia nd din nhdm bi mat chi tiit gia cdng.
Til' khoa: Topography; Chi do cdt; Chieu cao nhap nhd trung binh be mat dd 3D; Mdi phdng.
ABSTRACT
This paper studies the influence of cutting parameters on the topography of the grinding wheel surface. In the present study, experimental and data processing methods were applied, thus investigating the relationship between cutting parameters and parameters characterizing the topography of the grinding wheel surface. The results of this study may serve as a basis for researches on the effects of the topography of the grinding wheel surface on the surface roughness of processed parts.
Keywords.- Topography; Cutting parameters; 3D Surface Roughness Medium height; Flat Grind.
1. DAT VAN D E ^^ niat cao va gia cdng dugc eac loai vat lieu cd Mai la mdt phuong phap gia eong cd vi tri rit ^o tinh eao. Qua trmh mai dupe thuc hien bing quan trpng trong gia cdng co khi, nd tao ra dupe so lupng Idn cac hat mai (luoi cit) tren b l mat cac chi tilt may cd dp chinh xae eao, chat lugng lam viec cua da mai tao thanh Topography ciia "^
TAP CHi CO KHi VIET NAM, S6 3 nam 2014 www.cokhivietnam.vn
da. Dudi tac ddng cua eae lire cat mdi mdt ludi cat tren be mat cita da mai dan dan bi ciin tii, bi vd manh va trdc hat, hmh thanh cae ludi cat sac mdi, ngoai ra eac hdc nhd tren be mat bi lap mdt phan bdi phoi mai. Nhiing hien tugng nay din den thay ddi Topography cua be mat lam viec eua da mai tuc la thay ddi kha nang cat trong qua trinh mai, lam anh hudng den tudi ben eiia da va chat lugng be mat chi tiet mai. Do dd, viec nghien cuu cac yeu td anh hudng den Topography be mat ciia da mai de gdp phan nang cao tudi ben cua da va chat lupng be mat cac san pham co khi la van de can thiet. Trong ndi dung bai bao, nhdm tac gia da trinh bay nghien euu anh hudng cua che dp cat (V j^ - tdc dp phdi (m/ph), t - chieu sau cat (mm/
htk)) den chieu cao nhap nho trung binh be mat da mai (S^) khi mai phang v$t lieu thep C45 bang da maiWA60.150xl3x31,75.
2. TRANG THET BI VA PHlJONG PHAP TIEN HANH THI NGHIEM
2.1. Trang thiet bj thi nghiem, hinh 2.1
* Thiet bi do Topography: Su dung diu do laser ZX-LD30V, bp Ampliphier ZX-LDAl 1 eua hang OMRON, cd cac thdng sd: Khoang each cam nhan ciia dau do 30 ± 2 mm; Dp phan giai 0,25 pm[6].
- Phan mem do: Smartmonitor.ver2.0.
- Phan mem xu ly: Matlab.
* May: Thi nghiem tren may mai dung cu:
ATC-40M Dai Loan, Cdng suit N - 1.1 Kw, tdc ddnj^=3400v/ph.
*f)a mai: WA60.150x13x31,75 cua Dai Loan.
* Dung cu su-a da: Dau sua da kim cuang loai 1 hat ed kich thudc: 8.5x40.
^ Vat lieu gia cong: Thep C45.
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Hinh 2 1: Anh chup thiet bj thi nghiem vdphdi tren mdy.
2.2. Phuong phap tien hanh thi nghiem Tien hanh thi nghiem do Topography be m|t da bang phuang phap do true tiep sir dung dau do laser vdi che dp cat (V ^, t) thay ddi tai 6 diSm thi nghiem theo eae budc sau: [2], [5], [9].
Budc 1: Sira da vdi che dp sua da (S^^ = Im/
ph; t^j = 0.01mm), tien hanh do Topography khoi thuy bl mat da mai. [5], [6], [8].
Budc 2: Tien hanh mai phang thep C45, sau thdi gian mai 1 phiit tien hanh do Topography be mat da. Trong qua trinh mai cu sau 5 phiit do lai Topography be mat da cho den thdi gian mai 30 phut thuc hien sura da.
Budc 3: Ket qua do thu dupe qua phan mem Smart Monitor la bang dii lieu excel dudi dang file excel.CSV. Tren ea sd ciia phin mim Matlab nhdm xay dung chuang trinh de xir ly sd lieu do, tinh toan cae thdng sd dae trung eiia Topography va xay dung bl mat 3D. [4], [6].
2014
3. KET QUA THI NGHIEM VA XC LY SO LIEU
Bdng 3.1: Ket qud thi nghiem do Topography be mat dd mdi WA60.150x13x31,75
TT
1 2 3 4 5 6
Bien ma hoa X, -1 1 -1 1 0 0
X, -1 -1 1 1 0 0
Bien thirc nghiem
(m/ph) 4 8 4 8 6 6
t ( m m / htk) 0.01 O.OI 0.03 0.03 0.02 0.02
Chieu cao nhap nho trung binh be mat da S^ (mm) theo thai gian mai T (phut) Khoi
thuy 0.658 0.641 0.657 0.641 0.649 0.649
1 0.619 0.708 0.751 0.876 0.781 0.755
5 0.610 0.687 0.715 0.827 0.770 0.736
10 0.609 0.678 0.682 0.745 0.712 0.675
15 0.629 0.655 0.706 0.760 0.670 0.664
20 0.615 0.677 0.698 0.874 0.719 0.709
25 0.645 0.695 0.759 0.892 0.736 0.731
30 0.636 0.669 0.771 0.853 0.757 0.758 Tir ket qua tren bang 3.1, xay dimg ham chieu cao nhap nho trung binh be mat da S^ (thong so dac trung cho Topography) phu thuoc vao che do cat (V ^, t), du doan moi quan he dang ham mir: f(Vp^,t) = k.V ^M''. Tuyin tinh hoa phuong trinh phi tuyen bang each logarit co so e 2 ve cua phirong trinh ta dugc:
Ln(f(V„K,t))=to(k)+a.to(V^J+b.ln(t).
Dat y=hi(f(V_,,t)), b„=hi(k), b =a, b,=b, x =ln(V^^), x,=ln(t) Suyra:y=bj+b,.X|+b,.x, (1)
Ta CO [X].[B]=[Y] -> [X]'-.[X].[B]= [X]l[Y]. Dat [M] = [X]l[X]
suy ra nghiem cua he la : [B]=[M]-i. [X]l[Y].
* Xac dinh phtrong trinh S^tal thoi dilm mai 1 phiit:
Bdng 3.2; Sd lieu xu ly kit qud do tai thai diem t = I phut
TT 1 2 3 4 5 6
Bien ma hoa X, -1 I -1 1 0 0
X, -1 -1 1 1 0 0
Bien thirc nghiem V„,(m/ph)
4 8 4 8 6 6
t (mm/htk) 0.01 0.01 0.03 0.03 0.02 0.02
S^
0.619 0.708 0.751 0.876 0.781 0.755
L n ( V , ) 1.386 2.079 1.386 2.079 1.792 1.792
Ln(t) -4.605 -4.605 -3.507 -3.507 -3.912 -3.912
Ln(S_) -0.480 -0.345 -0.286 -0.132 -0.247 -0.281 TAP CHI CO KHi VIET NAM, Sd 3 nam 2014
www.cokhivietnam.vn
Vai ma tran [^] =
1 1.386 -4.605 1 2.079 -4.605 , 1.386 -3 507 1 2.079 -3.507 1 1.792 -3.912 1 1 792 -3.912
; [1-] = -0.480 - 0 345 -0.286 -0.132 - 0.247 -0.281
Giai he ta cd nghiem [B] -
Thay vao phuong trinh (1) va bien ddi ta cd:
^ S = e""^"*^ V "^"^^ t" '^'''' - 1 088 V "^"^^.t" "^''''
* Danh gia do tin cay cua ham hdi quy thwc nghiem:
- Md hinh toan hpc: [7] ^ i Ta cd dp tin cay ciia ham phi tuyen:'" = ——^—
0.0845 0.2097 0.1864
Trong dd: ' ' • > " = ^ T X ' ' n: Sd thi nghiem;
7Z.v->,r
Gia tri ciia cac thi nghiem;
Gia tri ham hdi quy thuc nghiem, Gia tri trung binh cua cac thi nghiem.
Suy ra:
i<> -yy-
Ap dung danh gia dp tm cay eua phuong trinh tren ta ed bang sd lieu tinh toan nhu bang 3.3.
Bdng 3.3: Gid tri tinh todn cua cdc biin hdi quy thuc nghiem
TT
1 2 3 4 5 6
X,
1 + 1
•1 + 1
0 0
X, -1 -1 +1 +1 0 0
V , ( m / p h ) 4 8 4 8 6 6
t (mm/htk)
0.01 0.01 0.03 0.03 0.02 0.02 Tong
Trung binh
T 0.619 0.708 0.751 0.876 0.781 0.755 4.490 0.748
T, 0.6168 0.7133 0.7570 0.8754 0.7642 0.7642
( T - T ) ' 0.016727 0.001627 7.11E-06 0.016299 0.001067 4.44E-05 0.035771
( T - T , ) ' 4.8IE-06 2.82E-05 3.58E-05 3.49E-07 0.000283 8.4E-05 0.000436
TAP CHi CO KHi VIET NAM, S6 3 nam 2014 www.cokhivietnam.vn
Thay gia tri tinh toan trong bang (3.3) vao phuang trinh ta co:
0.035771-0.000436 „ „„
r = = 0.98 0.035771
-D6thihmh3.1.
chieu cao nhdp nhd trung binh be mat dd mdi WA60.150x13x31,75 (SJ tgi thai diim mdi 1 phut.
* Tu-OTig tu* ta xac dinh phirtmg trinh S^tai thM diem mai 5 phut den 30 phut nhy sau:
- Thai diSm mai 5 phut: S^= e-»»='«.V^^»"".
t» '<•" = 0.9775.V ° "".t°"", do tin cay r = 0.95.
- Thai diSm mai 10 phiit: S_= e-"™.V^,""".
(0095= 0.7786.V »-i«'.t»°", do tin cay r = 0.93.
ph . . . .
- Thai di6m mai 15 phiit: S^= e-o°»'.¥/«'''.
(0 113 = 0 937 V »-°"'.t»'", d6tincayr=0.84.
ph ' -
- Thai diSm mai 20 phut: S,= e-»°'».V/^^".
t° " " = 0 939 V "•2-" t° '^'\ do tin cay r = 0.92.
• p h ' •
- Thai diSm mai 25 phiit: S,= e» '".V^^""".
,0.1804 = 1 145V "'"-t"""", do tin cay r = 0.91.
• p h ' •
- Thdi dilm mai 30 phiit: S^= e'-^^lV/ ""^
(0.1994 = 1 35 V "-'""' t"''^^^ do tin eay r - 0.99.
ph
Theo kit qua thi nghiem tren bang 3.1, dd thi hinh 3.1 va ham quan he giua chi dp eat vdi thdng sd dae trung Topography tai cae thdi diem TAP
mai, ta thay eac ham quan he nay dang ham sd mil nhu du doan vdi dp tin eay cao. Che dp cat (V |^,t) ed quan he ti le thuan vdi chieu cao nhap nhd trung binh be mat da mai (S^); trong dd, chieu sau cat (t) cd anh hudng nhieu ban tde dp phdi (V 1^). Cae ket qua thi nghiem trong bang 3.1 cho thay, giai doan dau da mdn nhanh (tai thdi diem mai 1 phut, chieu eao nhap nhd trung binh be mat da mai tang), nguyen nhan la sau khi sira da cac hat mai (ludi cat) phan bd ngau nhien tren be mat da, khi tien hanh mai (thdi diem mai 1 phut dau) mpt sd hat mai d vi tri khdng thuan Ipi hi bong trdc ra khdi be mat da dan den lam tang chieu cao nhap nhd trung binh be mat da (S^). Giai doan mai tiep theo, da mdn dn dinh (thdi diem mai 5 phut, 10 phiit chieu cao nhap nhd trung binh be mat da mai giam). Dae biet, d mdt sd cap che dp cat ta thay chieu eao nhap nhd trung binh be mat da cd xu hudng tang tai eae thdi diem mai 15 phiit hoac 20 phiit, nguyen nhan la trong giai doan nay khi ap lue mai cang tang, sd lugng hat mai bi bde tach ra khdi be mat da cang nhieu khi dd nhieu hat mai mdi nhd len tren be mat da mai tao ra cae ludi eat mdi, lam tang chieu eao nhap nhd trung binh be mat (hien tupTig tu mai sac cua da, tai thdi diem 15 phiit ham sd mii cd dp tin eay la thap nhat). Den mdt giai doan nao do (thdi diem mai 30 phiit), neu tilp tue mai thi be mat da bi trdc vd theo timg manh nhd, khi do ehieu eao nhap nhd trung binh lai cd xu hudng tang (giai doan mdn pha buy eiia da) ta phai tien hanh sira da.
4. KET LUAN
Nghien cuu anh hudng ciia ehi dp e5t (V ^, t) den Topography be mat cua da mai la cin thilt.
Cac ket qua thu dupe trong bai bao cd y nghia ly luan va thue tien trong viec nghien cim, danh gia Topography be mat cua da mai. Dua vao cac «=
CHi CO KHi VIET NAM, S6 3 nam 2014 f j ^ www.cokhivietnam.vn • • •
bieu thiic quan he giiia che do cat voi thong so nang suat gia cong trong qua trinh mai. Cac v5ii dac tnmg cho Topography ciia be mat da, ta co de nghien ciiu, phan tich anh huang tong hopt^
the nghien ciru duac su thay doi ciia Topography che dp mai - Topography ciia da - do nham be mjl bg mat da mai, tim ra che dp mai hop ly, gop chi ti8t gia cdng dang duac tiep tuc nghien clhi phan lam tang kha nang cat got cua da, keo dai se cho thay ro nguyen nhan true tiep (sir thay d6i moi ben ciia da mai... Tir do giiip cho viec nghien Topography) va nguyen nhan sau sa (chi dp c5t) ciiu phuang phap dam bao chat luong be mat va anh hirong den dp nham be mat khi mai.'l*
Ngay nhan bai: 24/02/2014 Ngay phan bien: 15/3/2014
Tai lieu tham khao:
[ 1 ]. Nguyin Dac LOG (2000), Cong nghe che tgo mdy theo huang img dung tin hoc, NXB. Khoa hpc va ICy thual [2]. Tran Van Dich (2006), Cdng nghe chi tgo mdy. NXB. Khoa hpc va Ky thuat. Ha Npi.
[3]. Banh Ti6n Long (2001), Nguyen ly gia cdng vdt lieu, NXB. Khoa hpc va Ky thuat. Ha Npi.
[4]. Pham Thj Ngpc Yen (2009), Ca sa Matlab vd img dung, NXB. Khoa hpc va Ky thuat. Ha Npi.
[5]. Nguyin Dac Lpc... (2006), S6 tay cdng nghi chi tgo mdy tap 2, NXB. Khoa hpc va Ky thuat. Ha Noi.
[6]. Nguyin Huy Nmh, Nguyin Van Thien (2013), Phuang phdp do Topography bi mat ciia dd mai bhngcm bien laser. Tap chi KH&CN Trirang Dai hpc Cong nghiep Ha Npi.
[7]. Nguyin Doan Y (2000), Giao trinh Quy hogch thuc nghiem, NXB. Khoa hpc va Ky thuat - Ha Npi.
[8]. Tran Minh Diic (2002), Nghien cim dnh hudng cug cdc thong so cong nghe khi sira dd din tuii bin ciia da mdi khi mdi Iron ngoai, LATS ma so 020109.
[9]. Ngo Cucmg (2009), Nghien cim lua chon che do cdt vd cdc biin phdp cong nghe di ndng cao hieu quit Jtilih te - ky thudt khi mai thep khong gi 3X13 bdng dd mai Hdi Duong, Bao cao dl tai nghien cim khoa hpc dp Bo GD&DT
[10]. S.Malkin (2000), Grinding Technology Theory and Applications of Machining With Abrasives, UnivetsilJ' of Massachusetts.
[11]. D.A. Doman*, A. Warkentin, R. Bauer (2005), A survey of recent grinding wheel topography models.
Department of Mechanical Engineering, Dalhousie University, 1360 Barrington Street, Halifax (Nova Scotia), B3M 3K5 Canada.
[12]. H. Ramasawmy, L. Blunt (2001), 3D surface topography assessment of the effect of different, Mechmial and Production Engineering Department, Faculty of Engineering, University of Mauritius, Reduit. Mauritius.
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