ANH Hl/dNG CUA CHE DO SUfA D A DEN TOPOGRAPHY BE MAT DA MAI
INFLUENCE OF WHEEL CORRECTION MODE ON THETOPOGRAPHY SURFACE OF GRINDING VI/HEEL
Nguyen Van Thien, Nguyen Huy Ninh
Tom tSt
Topography be mat cua da mai la thdng sd dac tnmg cho cau tnichinh hoc cua be mat da mai. Nd anh hudng dfn iupng bdc kim loai, do nham be mat gia cdng, ldc mai, rung dong va tudi ben cda da. Topography phu thuoc vao dp hat, cau tnic da mai, cdng nghe che tao da mai va che dp cdng nghe khi sda da. Noi dung bai bdo nghien cihi cac thong so inh hudng den Topography be mat cda da mai td do dua ra nhflng quyet dmh cong nghf hpp ly 1^ rit can thiet
Td khoa: Topography, tudi ben, Idong bdc, dp nham, Ide mai, sda da, mng dpng.
Abstract
The grinding wheel surface topography is a parameter that characterizes the geometry of the grinding wheel surface. It affects the amount of metal removal volume, suriaeemughness,grindingforee, vibration and wheel redress life cycle. Topography depends on the grain structure of wheel, wheels manufacturing technology and correction mode of wheel. The study of the parameters affecting the surface of the grinding wheel Topographies in order to make a decision technology is essential.The paper presents the effect of correction mode to the surface Topographies of the grinding wheel.
Keywords: Topography, Wheel redress life cycle, removal volume. Surface Roughness, Grinding Force, Wheel Correction, Vibration,
ThS. Nguyen VanThien
KhoaCaktii,TnJdngOaihocCongnghiepHaNpt TS. Nguyen Huy Hmh -Tnidng Dal hoc Bach khoa Ha Npi Email: [email protected])m
1.0ATVANDE
Qua trinh mai duac thiic hien bang cac laoi cat phan bd ngau nhien tren be mat lam viec cua da mai, tao thanh Topography cua da. Do tac dgng cua cac lac cat, rung dong va nhiet do phat sinh trong qua trinh cat, moi mot luoi cat tren be mat cua da mai dan dan bi mon, bj cun. Mat khac, cac phoi mai sau khi bi tach ra mot phan bam dinh len be mat da lam thay ddi dieu kien cat, giam kha nang cat got cua da.
Ngaynhanbai: 05/01/2014 Ngaydiapnhandang: 18/3/2014
Sau mgt thdi gian lam viec, da khong dam bao kha nang cat da dinh, ngUdi ta phai sCfa lai be mat lam viec cua nd.
Dudi tac dong cua dung cu silTa da (mui kim cuong) cac hat mai bi vo va hinh thanh cac luoi cat sac mdi, mot so hat mai nam d vi tri khong thuan loi co the bi tach ra khoi chat ket dinh, cac hat mai mdi xuat hien tao thanh cac ludi cat mdi. NhQng hien tifdng nay tao nen Topography ban dau cua be mat lam viec cua da mai, anh hadng den dong
ldc hgc trong qua trinh mai va kh^
nang cat cua da mai, quyet dinh tuoi ben cua da va chat Iddng be m^t chi tiet mai. Do do viec nghien CLTU cac dac trdng cua Topography da mai va dieu kien hinh thanh chiing la mgt nhi^m vu quan trong. Bai bao nay nhom tac gia nghien cdu ^nh hddng cua che do cong nghe sda da den Topography cCia be mat da mai.
2. ccr S 6 LV THUYiT v l QUA TRiNH M 6 N D A M A I V A PHl/CtNG PHAPTOPOGRAPHY
2.1. Mon da mai
Mon da mai la mgt qua trinh rat phdc tap. Qua trinh mon da la tong hop cua nhieu qua trinh mon khac nhau xiy ra tai vung cat. Cac nghien cdu da dua ra cd che mon va anh hddng cOa cac yeu to khac nhau den mon da gom: da mai va cac dac tinh cCia nd, phoi, che do mai, tddi nguoi va nhieu yeu to khac Viec nghien cdu cd che mon da la cfl
* Um(mm)
Kphdl) o f ; ~ ""*•
- ^ X o L ^ C i ^ T .
Kmh 1. Mdi quan he gifla Iddng mon da vdi thili gian cat
OA: giai doan mon ban daujAB: giai doan mdn k dmh; BC giai dogn mon kbocliet
1 4 TapdiiKHOAHOC&CONG NGHE. So 2 1 . 2 0 1 4
SCIENCETECHNOlOGYl
sd hdp ly de xac djnh tuoi ben cua da.
Dien bien qua tnnh mdn da mai tdong t d nhd cac qua trinh mon cua dung cu c^t khac bao gom 3 giai doan (hinh 1), - Giai doan 1 la giai dogn mdn ban ddu: Thdi gian mon ban dau T^ nho nhdng do mon ban dau U^ Idn. Nguyen nhan la sau khi sda da mgt so hat mai cd vj tri khong thuan Igi cho qua trtnh cat hoac cac hat mai lien ket khong chat che vdi nhau. Cac hat nay lien tuc bj tach ra khoi chat ket dinh.
- Giai dogn 2 Id giai dogn mon on dinh: Thdi gian lam viec cua da dUdc tinh trong giai doan nay. Do mdn cua da trong giai doan nay phu thugc chu yeu vao dac tinh cua tai trgng co nhiet.
- Giai dogn 3 Id giai doan mdn khdc lietDa mai bj vd manh Idn, khi xuat hien cd the kem theo chay mai hoac vet gan, khi do can phai tien hanh sda da,
Cd the nhin thay tong quat cd 3 co che mon chu yeu: Cun tu hat mai, vd hat mai va tach rdi hat mai, phoi lap vao cho trong gida cac hat mai. Tuy thugc vao dieu kien mai co the xay ra cac dang mdn sau (hinh 2):
- Hat mai nam d vi tri khdng thuan loi tren be mat da hoac ddoc gid khdng chat bdi chat ket dinh, dddi tac dung cua ldc cat chung bj tach ra khdi be mat da. Nd cd the xay ra theo be mat lien ket (gay cau lien ket) khi sda da hoac do hat mai bj pha huy ve the tfch.
- Cac canh va dinh cua nhdng hat mai nhd ra nhieu nhat mgt phan bi vd vun vang ra khdi hat mai, mgt phan bi mon va bi li do ma sat vdi be mat chi tiet gia cong. Tren be mat hat mai xuat hien cac dien tfch phang do bj mdn gay khd khan cho hat mai an sau vao be mat gia cdng.
- i^at mai bj vd meinh Idn.
- Hat mai bi vd thanh nhieu m^nh nho, tao thanh nhieu Iddi cat sac hon.
- Phoi cat ra cung vdi manh vun hat mai va chat lien ket bi mon roi vao cac 16 hong cua da va bit kin chung lam mat cac gdc c^t cua hat mai, khi do khS
nang luan ehuyen phoi lam giam tinh c^t ggt.
- Kim loai gia cong do ngdng ket hoac do tac dyng hoa hgc vdi vat lieu hat mai bj dinh vao cac dinh hoac tren be mat cac hat mai.
- Khi cac hat mai bj vd va bi roi ra, khi dd be mat lam viec da mai se hinh thanh cac Iddi cat mdi, de lg ra cac Idp hat mai mdi, sd khoi phuc kha nang cat nay ddoc gpi la tinh t y mai sac cua da mai.
Cac dang mdn tren xuat hien dong thdi trong qua trinh mai, tuy nhien tuy thugc vao dieu kien gia cong cu the ma mgt dang mon nao do the hien rd nhat.
^ r - :
Hinh 2. Cac dang mdn cua da mai a) hot mai bi ciin, b) hat mai bi va tilng manh nhd; (j hat mdi bi va manh Idn; d) hat mai bi trdc; e) hat mdi bi mdt goc cdt; g) hat mai bi che lop bdi phoi vd cdc tap (hdt
2.2. Sdra da mai
Viec sda da khi mai nhiim muc dich tao bien dang ciia da mai, khdi phuc lai do chinh xac ve hinh dang hinh hoc cua da mai sau moi chu ky lam viec cua da, Tao ra Topography hgp ly cda da nham
KtioangcJchiCr<
(Jen be rn9i da n\
nang cao tinh cat, tuoi ben cua da mai va md rong kha nang cdng nghe cua da mai, gop phan nang cao do chfnh xac va chat Idgng be mat gia cdng.
Qua trinh sda da gdm hai giai doan:
Tao bien dang va lam s^c, -Tao bien dang da la lam cho da mai cd mgt bien dang chinh xac phu hdp bien dang cua chi tiet can gia cdng.
- Lam s^c la qua trinh tao kha nang cat cho da mai bang each ha thap do cao Clia chat ket dinh tren chieu cao bien dang da de tao ra cac ranh thoat phoi va lam cac hat mai (Iddi cat) nhd cao khdi chat ket dfnh tao ra cac ludi cat tren hat mai.
2.3. Phirong phap do Topography Tap hgp cac loi ldm cCia mgt be mat da mai duoc xac dinh trong khong gian ba chieu vdi nhdng dac trdng cy the cua no thi dugc goi la Topography cua da mai, De danh gia Topography cua da mai, ngudi ta da dda ra cac thdng so mo ta dac diem chfnh, nhdng net dac trdng cua Topography be mat da nhd: Can bae hai cua sai lech trung binh binh phuong (5 ), chieu cao nhap nho trung binh cua be mat (S^), do lech phan bo chieu cao be mat (S^J...
Topography ludn bien doi trong qua trinh mai. Sd bien doi cua Topography phy thugc vao do hat, cau true da mai, cdng nghe che tao da mai, vat lieu da mai, dang Topography khdi thuy dat ddgc sau khi sda da, t i i trong ca nhiet
Oen laser birdrc song lien tyc
Cam bien laser tam giac
o*>
?
J 0 n ^
- 1 / X , ^ ^ Cam bien v|
f \ ^ m \ ~
T ,^u kmh i X \ tri (PSD)
..'-'''
< •
o / / / ,
Gia (5& cam bien tuin vj Iri Hinh 3, Nguyen ly do Topography da mai sill dung cam bien laser
Ban m^v chuven ddng hai pht/ang dong dong CO birdc
So21.2014•TapdiiKHOAHOC&CONGNGHE'i:
tac ddng tren hat da mai, tren chat ket dinh va phy thuoc vao vat lieu gia cdng, che do cong nghe khi mai cung nhu dgng luc hgc qua trinh mai, tinh trang dinh bam phoi tren be mat da mai... Topography anh hddng trdc tiep va quyet dinh den kha nang cat, lUc cat, rung ddng trong qua trinh mai, do mdn da, tuoi ben cua da va chat Idgng be mat chi tiet gia cdng,
Trong qua trinh mai viec xac dinh duoc Topography cua be mat da mai cd the giup cho nha cdng nghe nghien cdu dddc anh hddng cua che do cdng nghe sda da den Topography, tCr dd, quyet dinh ddgc thdi gian sda da va che do sda da (chieu sau va bddc tien) phu hgp. Trong ngi dung bai bao nay nhdm tac gia sd dung phUdng phap do trdc tiep bang cam bien laser dUdc thdc hien theo nguyen ly nhu hinh 3.
3. TRANG THIET Bj TH[ NGHl|M
• Thiet bj do Topography: Sd dyng dau do laser ZX-LD30V, bd Ampliphier ZX-LDAl 1 cua hang OMRON (hinh4) cd cac thong so: khoang each cam nhan cua dau do 30 ± 2 mm; tan so do 150ps;
do phan giai 0,25 pm.
- Phan mem do: Smartmonitor.ver 2.0 - Nguyen ly do: Nhu hinh 5, vdi cac ehuyen ddng:
+ Chuyen ddng quay da mai: Sd dung ddng ccj servo ma hieu: SGMAH- 02AAA21, cdng suat 0,2 kW, toe do toi da 3000 v/p. Bd dieu khien Servopack SGDP-02AP. Tan so lay mau t = 10ms, bddcdoS^^^lOOnm.
+ Chuyen dpng doc true da cua dau do: Sd dung dong ca servo ma hieu: DCM50202-02-1000MS12, cdng suat 0,08 kW, tdc do toi da 2000 v/p. Bd dieu khien MODEL: DC5810. Bddc do S^ - 50pm. Thiet bi thi nghiem tren may nhd hinh 6.
- Phan mem xd ly: MatLab, MFC
• May: Thi nghiem tren may mai dung ey: ATC-40M Dai Loan, cdng suat N = 1,1 kW, tdc dp n^^ = 3400v/ph,
. Da mai: WA60.150xl3x31,75 cua
Hinh 5 So do nguyen ly do Topography be mat da mai
^iffra
Dai Loan.
• Dung cu siia da: Oau sda da kim cdong loai 1 hat cd kich thude: 8,5x40
4. TIEN HANH THI NGHIDM VA XlT Vi 50 Lifu
Tien hanh thi nghiem vdi che do sda da S^^, t^j thay doi tai 6 diem thi nghiem, Sau khi sda da tien hanh do Topography be mat da mai. Ket qua do thu ddgc qua phan mem Smart Monitor la bang dd lieu excel dddi dang file exeei.esv.
Tren ccJ sd cua phan mem MatLab va
Bang 1, Ket qua thi nghiem do Topography be mat da mai WA60.150x13x31,75
Hinh 6. Thlet bi thi ngtiiem do Topography be mat da mai
STI 1 2 3 4 5 6
Bien ma hoa X, -1 1 -1 1 0 0
Xi -1 -1 1 1 0 0
Bien thifc nghiem S,.(m/ph)
0,5 1,5 0,5 1,S 0,87 0,87
t5d(mm}
0,01 0,01 0,03 0,03 0,02 0,02
Thong so S, 0,575 0,591 0,712 0,721 0,65 0,658
dac trung Topography
s,
0,123 0.131 0,133 0,135 0,124 0,124
Si -0,434 -0,457 -0,4!1 -0,393 -0,349 1 -0,342
1 6 TapdiiKHOAHOC&CONGNGHE. S o 2 1 . 2 0 1 4
SCIENCETECHNOlOGYl
CHUONG TRINH DO TOPOGRAPHV BE MAT DA MAI Ta CO [X).[B] = [Y] ^ [X]'.(XJ.[B1 [xr.[Y].Dat[M] = [X]'.tX]
Suy ra nghiem cua he la [B]=[IV1]' M'.CYl
- Xac dinh phadng trinh S^:
-0,693 -4,605 ^
V d i m a t r a n [X] =
Hinh 7. Ket qua tinh toan cac thong sd dac tri/ngTopography be mat da mai bang phan mem l^atLab (S^^
^0,5m/ph,t^-0,01mm)
< l %
0,405 0,693 0,405 -0.139 -0.139 0,553"
0,526 0,340 0,327 0.431 0.419
-4,605 -3,507 - 3,507 -3.912 -3.912
giai he ta CO nghiem [B] =
Thay vao phirong trinh doi ta CO;
^ S , = e»-='5«.s^"'".t„"-"' - Xac dinh phJcrng trinh 1 -0,693 1
Hinh 8 Ket qua xay dung be mat 30 cua Topography da mai (S ^ -0 5m/ph t ^ = 0 Olmml ctJ sd ly thuyet cija ngon ngO lap trinh S^, S,^, S^^ phu thuoc vao che do sCra C " nhom tac gia xay dijng phan mem da S^,^ t^^ d u doan moi quan he dang iVlFC de xi:r ly so lieu do, tinh toan cac ham mu: f(S^a,tJ = k.S^,j'.t^^ Logarit co thong so dac trUng cCia Topography va so e hai ve cua phuong trinh ta duoc:
xay dung be mat 3D, ket qua tren bang ln(f(S^,t J)=ln(k)+a.ln(S J+b.ln(t J . 1 va hinh 7,8. Bat y = ln(f(S„,t J ) , b, = ln(k), b, = a,
TCf ket quS tren, ta xay dUng ham b, = b, x, = ln(sJ, Xj = l n ( t J
cacthongsddactrUngchoTopography Suyra:y=b„-i-b,.x,-i-b^Xj (1) Vdi ma tran [X] -
m^
0,405 1 -0,693 1 0,405 1 -0.139 1 -0.139 -2,096"
-2,033 -2,017 -2,002 -2.087 -2.087 giai he ta CO nghiem [61 - Thay vao phuong trinh doi ta Co:
, S = g-l,8B3B 5 0,0352 ^ 0,0
5 . " " " . t . > "
0,3156 0,0172 0,1862 (1) va bien
•2=1,3711.
-4,605 -4,605 -3,507 -3,507 -3.912 -3.912
-1,8838 0,0352 0,0412 (1) va bien ' " = 0,152.
So 2 1 . 2 0 1 4 •TapdiiKHOAHOC&CONG NGHE 1 7
- Xac dinh phuang trinh S
V&i ma tran [X] =
[Y] =
^ •
1 -0,693 -4,605 1 0,405 -4,605 1 -0,693 -3,507 1 0,405 -3,507 1 -0.139 -3.912 1 -0.139 -3.912
-0,835"
-0,783 -0,732 -0,934 -1.053 -1.073
giai he ta CO nghiem [8] =
Thay vao p h i ong trir h ( -1,148 -0,0696 -0,059 ) va b en doi ta co:
-^S^ = e-'•'^^S^/•''^^^t,;''•°" - 0,3173.
TCf bang 1 va hinh 9 ta thay, l<hi tang che do cong nghe sCfa da (S^^,tJ cac thong so chieu cao nhap nho trung btnh be mat (S), can bae hai cCia sai lech trung binh binh phUdng be mat (S ) tang, vdi thong so do lech chieu cao be mat {SJ ty le nghich vdi chieu sau va budc tien doc sira da. Cac ket qua nay cd the giai thfch nguyen nhan do cac hat mai (ludi cat) phan bo ngau nhien tren be mat da, khi sifa da mot so hat mai d vi tri khong thuan Ipi bj bong troc ra khdi be mat da, khi chieu sau sCra cang Idn, so luong hat mai bi bong tach cang nhieu lam tang chieu cao nhap nho trung binh be mat, khi do nhieu hat mat mdi nho len tren be mat da mai tao ra cac ludi cSt mdi.
5 . KET L U A N
N g h i e n cCfu cac t h d n g s o a n h h U d n g d e n T o p o g r a p h y b e m a t c u a d a m a i la c a n t h i e t . Cac k e t q u a t h u dUOc c d y nghTa ly l u a n va t h u c t i ^ n t r o n g v i e c n g h i e n CLTU, d a n h g i a T o p o g r a p h y b e m a t c u a d a m a i D u a v a o cac b i e u t h i J c q u a n h e giCfa cac t h o n g so d a c t r U n g
Hinh 9.06 tiii quan iie che do sita 6t {S^/J vdi cac thong so Sac tritng cua Topography (S^ S^, S^) Si mJi WA60.!50xl3x31,75
[4]. Li/u Van Nhang, Ky thjat mai kim loai, NX8 Khoa hoc va ky thuat, Ha Noi (2003).
[5]. Nguyen Doan Y, 6iao trinh Quy hoach thuc nghiem, NXB Khoa hoc va Ky thuat. Ha Npi [2O00).
[6]. Nguyen Huy i^inh, Nguyen Van Thi^n, Phuong phap do Topography be mat cja da m^i bang cam bien laser. Tap chi KH&CN trirclng DH Cong nghiep Ha NOI (2013).
[7]. J.A Badger, A.A. Torrance, "A comparison of two models to predict grinding forces from wheel surface topography" (40), Machine tools and Manufacture, pp.1099-1120, (2000).
[8], Tran Minh Diic, Nghien ciiu anh hudng ci)a cac thong so cong nghe khi sii^a da den tuoi ben oia da mai khi mai tron ngoai, LATS ma soO2O109(2002), [91- S.Malkin, Grinding Technology Theory and Applications of Machining With Abrasives, University of Massachusetts (2000).
[10], H. Ramasawmy, L. Blunt, 3D surface topography assessment of the effect of different, Mechanical and Production Engmeering Department Faculty of Engineering, University of Mauritius, ffeduit, Mauritius (2001).
[11]. G. Vikram, N. Ramesh 6abu, Modelling and analysis of abrasive waterjet cut surface Topography, Manufacturing Engineering Section, Department of Mechanical Engmeering, Indian Institute of Technology Madras, Chennai. 600 036, India (2002).
[12]. H. Utsunomiya, MP.F. Sutcliffe, U Sherdiff, PS. Bate, D.B. Miller, Three-dimensional topography of the matt surface in aluminiJin pJ rolling, Department of Engineering, Umversit^
Cambridge, Trumpington Street, CambridgeCB2l UK (2004),
[13] D.A. Doman*, A. Warkentin. R. Bauai|
survey of recent grinding wheel topography modefci Department of Mechanical Engineering, Daihou*
University, 1360 Bamngton Street, Halifax (N;^
Scotia), B3M3K5 Canada (2005) c h o T o p o g r a p h y c u a b e m a t d a v d i c h e
d o c d n g n g h e sifa d a , t a c d t h e t a o ra d u g c T o p o g r a p h y k h d i t h u y m o t e a c h h d p i y l a m t a n g k h a n a n g c a t g o t c u a d a , k e o d a i t u o i b e n c u a d a m a i , g i a m t i e u h a o d a m a i k h i s C f a d a . . . t C f d d , g i u p c h o v i e c n g h i e n c t f u p h u o n g p h a p d ^ m b a o c h a t l U d n g b e m a t , n a n g s u a t v a h i e u q u a g i a c d n g t r o n g q u a t r i n h m a i , T r o n g k h u o n k h o b a i b a o n a y , c h u n g t o i c h i d e c a p d e n a n h h u d n g c u a c h e d p c d n g n g h e sCfa d a de'n T o p o g r a p h y b e m a t d a v a d U a ra dUOc b i e u t h i f c q u a n h e giCra c h i i n g . Cac v a n d e n g h i e n c d u , p h a n t i c h a n h h u d n g c u a c h e d o c a t d e n T o p o g r a p h y v a a n h h u d n g c u a T o p o g r a p h y d e n n h a m b e m a t c h i t i e t g i a c d n g c u n g d a n g d u a c n g h i e n cijru.
Phan bien khoa hoc: TS. Tran BiJt Quy
TAI LIEU THAM KHAO
[1], Tran Van Dich, Cong nghe the tao may, NXB Khoa hgcva ky thuat. Ha Noi (2006).
[2j. BanhTien Long, Nguyen ly gia cong vat lieu, NXB Khoa hocva ky thuat, Ha Noi (2001).
[3], Pham Thi Ngoc Yen, Co sd MatLab va ling dung, NXB Khoa hocva ky thuat. Ha Ngi (2009).
18'TapchiKH0AH(3C&C0NGI^GHE. S o 2 1 . 2 0 1 4
