NGHIEN CIJTU-TRAO Ddi
^NANG CAO DO BONG SAN PHAM VOI PHUONG PHAP TIEN B A N G C A N D A O GIAM CHAN
IMPROVE THE GLOSS OF PRODUCT BY THE DAMPING TOOL IN BORING PROCESS
Ph^m S(m IVIinh, Nguyin Trircmg Sinh Trucmg Dai hpc Su pham Ky thuat TP. Hd Chi Minh TOM TAT
Trong qud trinh tien cdc mat tnf, hien tuang rung dong cua mui dao la mot trong nhihig nguyen nhdn ldm gidm chdt lucmg be mat vd dp chinh xdc ve hinh ddng hinh hoc. Bdi bdo ndy se ung d^ing cdn dao giam chdn nhdm hgn che hien tuang dao dpng cua mui dao vd tdng chdt luang be mgt trong qua trinh tien Id. Cdc kit qud thuc nghiem cho thdy khi tien v&i cdn dao gidm chdn, chdt lu(mg be mat tot han so vol cdn dao thudng. Ngodi ra, khi tien vdi cdc thong so khdc nhau, do bong be mat khi dung cdn dao gidm chdn chi thciy doi tie 5 fim den 7 fxm, tuy nhien, khi tien vol cdn dao thudng, do bong be mat (Rz) thay doi khodng 20 pm den 100 pm. Trong cdc tru&ng hap thi nghiem, cdn dao gidm chdn co the tien duac 16 co do bong be mat cao nhdt Id 2.23 fim v&i chieu sdu cdt 1.3 mm, van toe cdt 200 m/ph vd buac tien dao 0.05 mm/vong.
Tir khoa: Cdn dao gidm chdn, tien 16, do bong be mat.
ABSTRACT
In the turning process, the vibration of insert is a main reason for reducing the surface qualitry and the shape accurancy of product. In this paper, the damping tool will be applied for reducing the insert vibration in the boring process. The experiment result shows that when boring with the damping tool, the surface gloss has a clear improvement. In addition, with the damping tool, when boring with different parameters, the surface gloss (Rz) varies fi-om 5 pm to 7 fim, while, with the common tool, this value changes from 20 pm to 100 pm. Results also show that the best surface gloss (Rz) is 2.23 pm with the cutting depth of 1.3 mm, cutting speed of 200 m/min and the feed rate ofO. 05 mm/
revolution.
Keywords: Damping tool, boring, surface gloss.
ISSN 0866 - 7056
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NGHIEN CUTU - TRAO DOI
1. GIOI THIEU
Trong linh vuc gia cdng co khi, viec nghidn ciiu cac ydu td anh hudng den chat lupng gia cdng nhu h? thdng cdng nghe, cac ydu td ngoai canh, vat lieu, tudi ngupi... la mot trong nhiing yeu cau quan trpng nhat ciia nganh Cdng nghe cat gpt kim loai a mdi qudc gia. Yeu cau nay ngay cang cap thiet han khi cac the he mdi ve dao, may cat gpt, va vat lieu gia cdng ngay cang cd sy thay ddi dang ke.
Khi de cap den chat luang gia cdng, dp bdng be mat mjt chi tidt la mdt trong nhiing yeu cau quan trpng nhit cua qua trinh gia cdng. Ddn nay, da co kha nhieu nghien ciiu ve anh hudng cac phuong phap cat gpt, thdng sd eat gpt, hd thdng cdng nghe... den dp nham be mat trong qua trinh gia cdng tren may van nang ciing nhu may CNC. Tuy nhien, nghidn ciiu anh hudng Clia can dao giam chan, mdt trong nhiing cdng nghe mdi trong gia cdng c i t gpt, ddn dp bdng bd mat chi tidt van chua dupc dd cap den. Do vay, viec khao sat van de nay se dap iing cac ddi hdi khac khe vd dd bdng bd mat cua cac san phim hi^n tai, dac bidt vdi cac san phim xuit khiu.
Trong cdng nghe tidn, sy kdt hpp chuydn dpng quay trdn ciia phdi va chuydn ddng tinh tidn dpc true ciia dao se tao nen qud trinh tach kim loai ra khdi bd mat phdi [1-3]. Trong qua trinh nay, toan bO he thdng gdm phdi, dao va may ludn chiu tac dyng cua cac loai lyc khac nhau. Trong do, hidn tupng dao dpng cua mui dao se anh hudng ldn ddn dp nhip nhd td vi cua bd mat sau khi gia cdng [2]. Dao dpng nay se gay ndn anh hudng tieu cue ddn dd bdng bd mat [3] cung nhu dp chmh xac vd kich thudc [4] va hinh dang hmh hpc [5] ciia san phim. Trong cac nghien ciiu trudc day, khi can dao ti?n cang dai, hidn tuang dao ddng cua mui dao cang ldn [1, 5]. Kdt qua nay d | c biet thd hi?n ro trong qua trinh tien Id dai. Tu li do nay, thdng qua phuang
phap thyc nghidm, bai bao nay se nghidn ciiu anh huang cua can dao giam chin ddn dp bdng be mat cua chi tiet tidn Id.
2. PHlTONG P H A P THI N G H I E M Trong nghidn ciiu nay, can dao giam chan se dupc su dung cho qua trinh thi nghidm. Can dao gdm 2 phin nhu hinh 1: PhSn dau dugc cau tao dac bidt dd giiip giam rung ddng d dao, phin dudi cd ciu tao binh thudng nhu cac loai dao khac. Viec thidt lap, ga lap can dao giam chan cimg tuong ty nhu cac can dao binh thudng. Ca ciu giam chan bao gdm 3 phan: Phan than cd khdi lupng tuong ddi nang (A) nam giiia 2 b^c cao su (B) d 2 d i u ciia than can dao. Than can dao dupc bao bpc vdi mpt loai dau dac biet (C).
Ndu rung ddng tang ldn trong qua trinh gia cdng ma cd sii dung can dao giam chan, he thdng giam i chan cua dao se ngay lap tiic sinh ra lyc, ma nang lupng chuyen dpng ciia can dao se duoc | hap thu vao hd thdng. Kdt qua la rung dpng se i dupc giam tdi thieu va nang suat gia cdng dupc dam bao va tham chi la tang len.
^
A: Oieu diinh khoi doi trpng diinh B: Vong cao su 16 x>.
C: Dung dicb dau nhcm Hinh I. Cdu tgo cdn dao gidm chdn Ngoai ra, phdi trong qua trinh c i t se dupc lam tu thep C45. Day la thep cd thanh p h i n gdm Fe va C, trong do ndng dp cacbon cd trong thep la 0,45%, C45 dupc xdp vao l o ^ vat lieu cd tmh cacbon trung binh, thudng dupc dung rit nhidu trong thidt ke cac chi tidt may phd bidn nhu true, banh rang...Toan bd qua trinh cit gpt se dupc thuc nghidm bdi may phay EMCO MAXXTURN-65 (hinh 2a) va dyng cu cit TCMT 09 02 04-PF.
Dung cu cat va can dao giam chin dupc cung c i p bdi Cdng ty SandVik - Thuy Didn. Ngoai ra, de kidm chumg kha nang giam chan cua can dao
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NGHIEN cufu - TRAO D O I
do SandVik cung cap, can dao tiSn thong thuong cung se dupc sii dving trong qua trinh thi nghiSm.
Trong qua trinh thi ngliiSra, bo thong so cat gpt dupc sir dimg nhu Bang 1. Sau Ichi gia cong vai cic thong sa na, be mat 16 duoc IciSm tra dp bong nhu hinh 2b. Cac lc6t qua vh dO bong se dupc tiSn hanh thu thap va phan tich.
Bdng I. Thong so cdt
V^ (m/phit) 200 300 400
Chieu sau cat a (mm)
0.3 0.8 1.3
Biid'cti^n f (mm/v6ng)
0.05 0.12 0.19
a) b) Hinh 2: Qud trinh gia cong (a) vd kiem tra dd bong
be mat Id (b) 3. KET QUA VA THAO L U A N
tdc dp tidn dao vong (f) thay ddi tir 0.05 mm/
vdngddn0.19mm/vdng,vav$n tdc cat thay ddi tii 200 m/ph den 400 m/ph, can dao giam chan cho ket qua dp nham (Rz) cd xu huong giam tu 10 |j.m xudng 3 ^m. Gia tri dd bdng tdt nhit dat dupe khi f = 0.12 mm/vdng. Ngoai ra, dp chenh lech gifta cac gia tri khi thay doi f dao dpng ttr 1 ddn 3 lan. Trong khi dd, can dao thudng cho kdt qua dp bong bd mat Rz thay ddi tir 20 pm den 100 |am, ngoai ra, dd chdnh Ipch giua cac gia tri khi thay ddi f dao dpng tu 2 den 5 ian. Vdi ciing thdng sd cat gpt va vat lieu phdi, hinh 5 cho thay chat luong bd mat khi cimg can dao giam chat cao hon nhidu so voi can dao thudng.
Khi thay ddi buoc tien dao (f), dp nham ddi vdi can dao giam chan tuy chi bidn ddng rat nhd. Dp bien dpng Rz chi tu 5 p.m ddn 7 pm.
Tuy nhidn, vdi can dao thudng, sy thay ddi nay dao ddng tir 30 |im den 50 jim. Vdi 9 trudng hpp nhu hinh 3, ca 2 can dao ddu cd quy luSt kha gidng nhau, ddu dat dp nham cyc tidu tai f=
0.12 mm/vdng va bd mat cd xu hudng xau di khi budc tidn dao (f) qua nho hoac qua Ion.
ooooo
Hinh 3 trinh bay cac mau thi nghidm sau khi dupc cit vdi cac thdng cd nhu Bang 1 vdi hai loai can dao. Sau qua trinh do dp bdng nhu hinh 2b, cac gia tri dp bdng Rz dupc thu thap, tdng hop va so sanh nhu hmh 3. Nhin chung, khi
thay ddi chidu sau cat tii 0.3 mm den 1.3 mm. Hinh 3. Mdu thi nghiem sau qud trinh cdt ggt
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NGHIEN ClJU - TRAO OOl
• p i U m t'OmnmAoni I v U a K f - a U a H t a |
i».L9MRt r.aasMi^mic •r-Uaoi, f-Oiila [ T - U ^ f-O.H»^»o«|
—•— CliKko^lnchin • • - CtadaoHutal
ifin/i 4. Do bong be mat vdi cac budc lien dao (f) vd chieu sdu cdt (ap) thay doi
Can dao giam chdn T ^ ~ ~ Can dao thuang
-0.3mm f=0.12mm/vdng Vc-300m/ph
Hinh 5. Su thay doi cua do bong khi ditng cdn dao gidm chdn
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NGHIEN CijrU-TRA0D6l
4. KET LUAN
Qua qua trinh tidn hanh thyc nghifm vdi cac gia tri khac nhau ciia van toe cat (Vc), chidu sau cat (ap) va buoc tidn dao (f), vat lieu thep C45 dupc tidn hanh tidn Id vai can dao giam chan va can dao thdng thudng, cac kdt qua vd dp bdng bd mat cho thiy:
Can dao giam chan cho kdt qua vupt trdi so vdi can dao thdng thudng.
Sy vuot trpi ve dp dn dinh cua dp bong be mat klii su dung can dao giam chan vdi cac thdng sd c i t gpt khac nhau ciing dupc quan sat kha ro.
Trong cac trudng hpp tien Id, dp bdng bd mat Id co thd dat dupc vdi gia tri Rz = 2.23 pm khi tien vdi chidu sau c i t 1.3 mm, v^n tdc cit 200 m/ph va budc tidn dao 0.05 mm/vbag.*>
Ngay nhan bai: 14/9/2015 Ngay phan bidn: 12/10/2015
Tai lieu tham khao:
[1 ]. A. Siddhpura, R. Paurobally, A review of flank wear prediction methods for tool condition monitoring in a turning process, Int J Adv Manuf Technol (2013) 65.
[2], Erol Ttirke§, Suleyman Ne^eli, A simple approach to analyze process damping in chatter vibration, Int J Adv Manuf Technol (2014) 70.
[3]. Chih-Chemg Chen, Ko-Ta Chiang, Analyzing the design of vibration reduction with the mbber-layered laminates in the precision turning with a diamond cutting tool, Int J Adv Manuf Technol (2011) 57.
[4], Qilin Fu, Daniel Lundin, Cornel M. Nicolescu, Anti-vibration engineering in internal tuming using a carbon nanocomposite damping coating produced by pecvd process, Joumal of Materials Engineering and Perforaiance (2014) 23(2).
[5]. Balla Srinivasa Prasad & M. M. M. Sarcar, B. Satish Ben, Development of a system for monitoring tool condition using acousto-optic emission signal in face tuming—an experimental approach, Int J Adv Manuf Technol (2010) 51.
ISSN 0866 - 7056
T ^ P CHi CO KHi VIET NAM, Sd 10 nam 2015 www.cokhivietnam.vn