Nghiên cứu ảnh hưởng hình học dụng cụ cắt PCBN khi tiện cứng thép 2311 qua tôi đến độ nhám bề mặt

Lai Anh T u i n ' 'Trutog Cao dtog Giao thing Vfa tai III 'Trung tim Ky thuit Tilu chuto Do lutog chit lUpng Ding Nai 'Hpc vita Ky thuit Quto sfl TOM TAT Bdi bdo trinh bdy kit qud nghiin

NGHIEN Ciru ANH HU'DNG HJNH HOC DUNG CU CAT PCBN KHI TIEN CLTNG THEP 2311 QUA TOI

DlN DO NHAM B^ MAT \\

RESEARCH O N EFFECT O F PCBN GEOMETRY INSERT O N T H E SURFACE ROUGHNESS I N RIGID T U R N I N G C N C FOR 2311 STEEL ALLOY AFTER »•

H A R D E N I N G

KS Hoang Bi Khoa', ThS Dmh Hiiu Cuong', TS Lai Anh T u i n '

'Trutog Cao dtog Giao thing Vfa tai III 'Trung tim Ky thuit Tilu chuto Do lutog chit lUpng Ding Nai

'Hpc vita Ky thuit Quto sfl

TOM TAT

Bdi bdo trinh bdy kit qud nghiin cdu dnh hUdng cda hinh hoc dung cu cdt PCBN din dd nhdm

bi m^t khi tiln dng thip hdp kim 2311 qua tdi tren mdy CNC Cdc thdng sSdnh hudng din dd nhim

bi mat dUdc nghien cdu trong bdi bdo Id gdc nghieng chinh ciia dao, gdc cat trUdc ciia dao, bdn klnli

mm dao Cdc tdc gid dd sit dung phUdng phdp quy hoach thiic nghiim trUcgiao cdp 2 detim ra phUdng trinh cho quan hi cda 3 thdng so trin vdi dd nhdm be mat, cung nhU dimg phdn mim Matlab di tim m: cue tri tdi Uu cho dd nhdm be mat Kit qud nghiin ciiu Id cdc do thi dnh hudng cua cdc thdng si hinh hgc cua dung cdt den nhdm bi mat chi tiit gia cdng

Tfl khoi: PCBN: Matlab: Thip 2311; CNC; Tiin cilng

ABSTRACT

This paper presents results of research on effect of PCBN geometry insert on the surface roughness,

m ngid turning CNC for 2311 steel alloy after hardening Plane approach angle, rake angle, tod nose radial are considered which are parameters influence on surfa ce roughness Equations describe the relationship between parameters with surface roughness are determined base on using planning

7ZgZ::^:Z!r''''"'^''"'"'''"^^^^^^

Keywords: PCBN; Matlab; Steell 2311; CNC; Rigid Turning

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TAP CHI CO KHI VlfiT NAM, S i 7 nam 2016

I.DATVXNDE

Viec gia cing cic chi Uet dang true co dp

ctog cao v i ylu ciu phii dat dp nhim b i mat cip

8 trd lln, ddi hoi nhieu cing doan gia cing phflc

t«p khic nhau Theo phuong phap truyfo thong la

mii thi dto tdi nhieu vto de bat lpi trong sto xuat

Mii chi tiet doi hoi trang bi c i i ^ nghe phflc tap,

giy o nhilm moi trudng va kho cd the tai che lai

h^t mii Vi viy, Ufo cflng l i phUflng phip thay t h l

vi ngiy ctog trd nta quan trong trong sto xuit

vdi nhflng flu the cia nd Tita ctog cd thdi gian

gia cing nhanh qui trhih gia cing Imh hoat chi

phi dau tu thip giim giy i nhilm moi trUdng

tuii tho lim vile cia chi tiet cao [3] Trong tita

ctog do dung Ifldi cit don nta co the dieu chinh

chinh xic gdc cat de dtog gia cong cic be mat

phiic t?p cua sto phtoi Viy vfa dl dat ra la chpn

pi^ thing s i da nghiin cflu trudc diy va nghiin

cflu thim cic goc cat trong tita cflng de nhim tii

flu hda quy trinh cong nghe

2 THIET KE THU'C NGHI$M

2.1 Chpn phuong i n thi nghiem

Bai bao nghiin cflu anh hudng cua gdc

nghitog chmh, gdccattrfldcvabto kinh miii dao

din do nhim bi mat nen phfltog phip nghita

cflu dflpc chon la phfltog phip qui hojch thfle

nghiim trflc giao cip 2 Cic yta t i khic la co

dinh

Vit hiu sieu ctog dupc dtog de che tap cac loai dao tita bang Nitrit Bo dupc dtog de gia cdng mat ngoii, mat dau, mat 16 Cac thing s i hinh hpc cua dap tita btog Nitrit Bo ctog phy thupc vio tinh chat vit h t a cua chi tiit Khi gia cong thep nhiet luyfo: y = 5 -^ (-15") gdc nghieng chmh <p, = 30''^-60° vfa tic cat 80m/phut den 180m/phut [IJ Trong tita cflng sfl dimg minh

CBN thfldng gia cing vdi tic id cat 100 +180

m/phut [5] M Dogra d i nghiin cflu dung cu cat CBN vdi bto kinh mui dao tieu chufa khic nhau (0.4, 0.8 v i 1.2 mm) dupc sfl dung vi ket qua cho thay sU gia ttog bfa kinh mui dao dto den su ttog lUc day dtog k i [4] Khi gia cing vdi lupng chsy dao 0.02 + 0.15 mm/vdng thi be mat gia cong cd dO nhap nho te vi giim Neu lupng ch^y dao S> 0.15 mm/vong thi bien d ^ g dto h i i

se toh hudng den sU hmh thanh cac nhap nho te

vi, ding thdi ket hpp vdi fah hutog cua cac yeu

t i hinh hpc Iam ttog nham be mat [2] Viy, mifo thUc nghiim chpn li bto kinh mui dan tfl 0.4mm den 1.2mm, gdc nghiing chinh 9, = 30"+60°, gdc cat trUdc i m y = g'+lS"

- Thi nghiem dupc gia cing tren miy CNC CTX310 (Mnh 2.), sfl dung mtoh dao PCBN CNGA1204 Idp phu KB5625 (65% him lupng CBN) Cto dao sfl dung trong thi nghi|m MCMNN2020K12

dn Ihi nghiim Htnh 2 Mdy vd cdc thiit bi thl nghiim

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- Phoi thi nghiem la thep 2311 nhi?t

iuyen c6 dp ci5ng 52HRC, chieu dii phoi 120mm

va du6ng kinh 60mm

- Van t6c cat: V = 160m/phut;

- Chieu sau cat: t = 0.2mm;

- Li(dngchaydao:s-0.1nmi/v6ng

Cac y^u t6 tr^n luon on djnh trong qud

trinh thiic nghifim

Dang cua phiiong trinh h6i qui nhii sau:

y=b, - b,ii - lijij+hrt - h^«,i;-^ buJ,!,+baijij+bu^-Miai^+boi^'(1)

Cac y^u t6 anh hiidng nhii sau:

Xji Goc nghieng chinh dung cijc5tq)| (dp);

x^: Ban kinh miii dao dung cu cdt R (mm);

Xji G6c trUdc dung cy cdt y (do)

Bdngl Gid tri vd khodng biin thiin cua cac yeu td

dnh hudng

Gid tli

Klioiiiig

b i b

thian

<

^'

« i

40" S X, S 60»

50"

IO"

X

0.4 S X; £ 1.2

0.8

0.4

9* fix, SIS"

11«

2'

Bi ti?n tinh toan cac he s6 thyc nghi?m

cOa mo hinh toan h6i quy vk tien hanh cac bii6c

xi£ ly s6 Mill, ta chuyen sang ma hoa gia tri khong

thli nguyen vdi gia tri can tren (+1), gia tri can

dudi (-1) v4 gia tri trung bmh x_''=0

Tmng khoir^ kh6ng gian md rOng a = 1215

% ^ = l - 2 1 5 : x ; _ = 62.2^

x ^ ^ = 1.28mm; x ^ „ ^ = 1 3 4 "

3- = _ 1.215; x' = 3 7 8 "

= 0.32min; xL„ = 8.6°

V6ik=3; a^ = 1.476; a = 1.215

De dat dii(?c cac gdc cat dap iing mifei thiic nghiem da thiet ke, c h l tao cac chi tiet nfim Cac chi tiet n^y diidc ga chung vdi can dao tien tren dai dao va dieu chinh bang may sao cho mui dao nam tai vi tri m?t phang tam tryc (hinh 3)

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Hmh 3 Phuang dngd dao thdc te thi nghiim

2.2 Ket q u i thUc n g h i e m

Bdng 2 Kit qud dd nhdm bi mat theo bdng qui hoqc

thuc nghiem

STT

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

B i l n m a

\

+ + + +

+ -t-+

-t ^

+ +

-t-+

-t-X j

+

-t-+

1.215 -1.215

0

0

0

0

0

^

-

-t-+

+ +

0

0 1.215 -1.215

0

0

0

"^

-t-0

0

0

0 1.215 -1.215

0

2 ^ = 0 7 7

m i 2 0 1 6

Y(m)

0.8 0.91 0.62; 1.02 0.9 1.03 0.62 0.65 0.67^ 0.51 0.9 1.12 0.57 0.52 0.71

%

1

1 t

t

k

Bang 3 Kit qua do nhdm he mat tm tdm phUdng dn

STN

1

2

3

4

« i

50°

50»

S0»

50°

* J

0.8mm

O.Smm

0.8mm

O.Smm

"a

11°

11°

11°

11°

Gia tli tnmg binh y

yi(i"») 0.69 0.64 0.67 0.70 0.675

Sau khi CO ket qui thi nghiem tai cic vi

tri cua phUOng an qui hoach thiJc nghiem trUc

giao cip 2 ta se Uen hinh tim phuong trinh hoi

qui(l)

3 X i r i t KET QUA VA D A N H G I A

3.1 Xill ly kft q u i thdc nghiim

Phuong sai tai hien idoc tinh theo m=4

lin lap ciia thi nghiem 6 tam:

s 4 = ^ I S , C y , - y ) ' = 0.0007 (2)

S ^ = 0.026

Sau khi bien doi m(5i (1) phuong trinh

h6i qui co dang:

y=b;tlift-b.i.-b,i,-brti.+ii|rti,+iyo,,ib;i;t^^+l4,; (3)

Vi sau khi doi bien ma tran d bing qui

h o ^ thfle i ^ l m trflc giao nen cic he so trong

phflong trinh (3) doc IJp nhau vi xac dinh theo

c6ng thfle sau diy

bi = ;I2f=iyoXo»

2 ^ = : Ta^

(4)

Bdng4 Kit qud cdc hi s6 trongphUdng trinh (3) tinh tiieo cdng th^c (4)

K

bl

b

bs b,^

0.7700 0.0789 -0.0911 -0.0081 0.0238

bi3

b„

bi,

b ;

bia

-0.0438 -0.0738 -0.0321 0.2523 -0.0625 Cong thfle tinh dp lech chuan cfla he so b trong phflOng trmh (3) Vi ma trin thfle nghiem cap II sau khi d6i bi&i l i ma tran trflc giao nen moi he s6 b trong phflong trinh (4) dpc IJp va xic dinh vdi dO chmh xic dupc tmh theo cong thfle sau:

\ = ^ = 0-0094

S b „ =

-•1 - i»-?) +:(•"'-?j"+(2k-2+n.)(;s')

Sj, = 0.0127

PTHQ:

Kiem tra y nghia cua cac hi s6 trong

(5)

".^t^

So sanh t^ v i t|,(p.f) de tim ra h« s6 c6

b = ^n'ni^iu

!:!!«(xi.^f

je{1.23};u=1.2.3

Trong do: So mflc dp tfl do f=n||-l (n,: So

lan thi nghidm d tim)

f+4-l=3 p=0.95: Xac suit tin ciy:

Tra bing t^(pfl = tj(0.95.3) 1

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4.KETLUAN

Vdi ket qua nghien cflu tren thi ro rang cac yiu to nhil gdc cat tnidc, gdc n ^ e n g chinhii hiidng nhieu den do nham hi m^t Qua ngliien cdu da xac dinh diidc cac thong so hinh hoc c4a dung cu (At di cho ra k^t qua toi liu la do nham b^ mat gia cdng nho nhat Vdi khS nang cat kho cfla

PCBN cd the cat thep sau nhiet luyen tdi do cijtng 68HRC thi ro r ^ g la nhiing l^i ich ma cdng ngh?

nay mang 1^ cho chung ta sii liia chpn hoan hao hon so vdi cac phiidng phap ti&i tinh thong th\iisas

khac.*;*

Ngay nhan bai: 12/5/2016

Ngay phSn bien: 22/6/2016

TM li^u t h a m khao:

[ 1 ] TrSxi Van Dich (2004); Gia cdng tinh be m^t chi tiit mdy NXB Khoa hpc va Ky thu^t, Ha NOi

[2] Trln W n Dich, Nguyen Trpng Binh Nguyen The Dat, Nguyin Viet Tiep, T r l n Xuan Vi^t (2009); Cdng Mgftg chi tao mdy, NXB Khoa hpc va Ky thuat, Hk N6i

[3] Viktoria Bana (2006), "Manufacturing of high preciseion bores" Doctoral thesis 2006, Delft Universityof

Technology, Holand 107

[4] M Dogra,V S Sharma, J Dureja (2011), 'E^ct of tool geometry variation on finish turning" Jouma|if

Engineering Science and Technology Review 4 ( 1 ) (2011) 1-13

(5] Chen W (2000); "Cutting forces and surface finish when machining medium hardness steel using CBN tools", Intemational Journal of Machine Tools & Manufacture, 40, pp 455-466

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