Upload
tuan-anh-pham
View
6
Download
0
Embed Size (px)
Citation preview
5/27/2018 bcthtap_5541
1/47
LUN VN TT NGHIP
ti: Tm hiu v cng ngh CNC
5/27/2018 bcthtap_5541
2/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
1
MC LC
LI NI U....1
PHN A : GII THIU CHUNG V SODICK2PHN B : NI DUNG BO CO THC TP
PHN 1: TNG QUAN V CNG NGH EDM........5
1.1.Nguyn l gia cng tia la in ( EDM).5
1.1.1. Gia cng tia la in dng in cc nh hnh 6
1.1.2. Gia cng tia la in bng ct dy... 6
1.2. Bn cht vt l ...7
1.3.Cc thng s cng ngh ca EDM..........9
1.3.1. c tnh v in ca s phng tia la in......9
1.3.2. Cc thng s iu chnh.......9
1.4.Gia cng EDM c th c phn loi nh sau.....12
1.5.Cc trc cn bn ca my EDM....13
PHN 2:TM HIU V MY CT XUNG( DIE SINKING EDM)..14
PHN 3: MY CT DY EDM( WIRE CUT EDM)...21
PHN 4: B IU KHIN CHNH TRONG MY CT EDM34
4.1.H thng servo AC...34
4.2.Mt s h thng mch trong my EDM...39
http://greub-machines.com/pmn-sodick-sink-e.htmlhttp://greub-machines.com/pmn-sodick-sink-e.html5/27/2018 bcthtap_5541
3/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
2
LI NI U
Trong qu trnh hc tp trong cc trng i hc, s kt hp gia lthuyt v thc hnh lun c nh trng v sinh vin t ln hng u. V
vy thc tp tt nghip l mt trong nhng phn rt quan trng gip sinh
vin nm cui hon thin kin thc, l bc chun b tt nht cho sinh vin
trc khi ra trng. Thc tp tt nghip gip cho sinh vin k thut tip cn
c r nht vi thc t sn xut ti cc nh my, x nghip, c tm hiu
v tip xc trc tip vi my mc thit b c hc trn l thuyt. Ngoi
ra trong qu trnh thc tp sinh vin cn c c hi nm bt c cng vic,
phng thc lm vic c nhng chun b tt nht v khng b b ng
trc khi tt nghip ra trng.
Trong qu trnh thc tp ti cng ty VPD Sodick, tuy ch c mt
khong thi gian ngn nhng vi s ch bo tn tnh ca thy gio hng
dn thc tp DUY PH cng cc anh ch em trong cng ty gip em
hiu hn v cng ngh CNC, c bit l cc my ct xung EDM.
Do thi gian thc tp c hn cng vi s hiu bit cn hn ch, bi vit
khng th trnh khi nhng sai st. Knh mong thy c, cng cc bn gip
v ch bo .
Em xin chn thnh cm n!
H Ni, ngy 12 thng 4 nm 2010Sinh vin thc hin
Lng Pht Ngc
5/27/2018 bcthtap_5541
4/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
3
PHN A
LI GII THIU
Sodick Co., Ltdl mt tp on sn xut my EDM (my tia la in)hng u Nht Bn chim 49% th phn my EDM ti th trng Nht vi
mng li trn khp th gii t Bc&Nam M, Chu u n chu Thi
Bnh Dng vi 4 nh my sn xut chnh (1 nh my ti Nht Bn (Fukui),
2 nh my ti Trung Quc(Shuzhou v Amoy) v mt nh my ti Bangkok
Thi Lan). Trong Cng ty Sodick(Thailand) Co., Ltd. ti Thi Lan l mt
cng ty trc thuc ph trch kinh doanh, phn phi thit b cho 3 nc Thi
Lan, n , Vit Nam. VPD Sodick (Thailand) Co., Ltd c a ch ti
P503 CT1 To nh Vimeco, Khu th Nam Trung Yn, Qun Cu Giy,
H Ni.
Sn phm chnh ca Sodick l cc my CNC trong lnh vc ch to khun
mu nh: My xung, my ct dy, my khoan l, trung tm gia cng, my
nh bng, my p nha, my Nano. y l nhng dng my cao cp cho
nhng sn phm c bng cao ng thi c chnh xc c m v nm.
Trn th trng Vit Nam c rt nhiu khch hng ln v ang s dng
thit b ca Sodick nh : Canon, Toho, Brother, Vietnam Auto Part, Iritani,
Nissei, Muto Technology, Hokuyo Precision..v..v..v.. v rt nhiu doanh
nghip Vit Nam khc nh Vin Cng Ngh B Quc Phng, Cng ty
HTMP, Cng ty Tn Ha..v..v.v.v.
Nh mt nh tin phong EDM, Sodick lin tc tin hnh nhng nghincu v pht trin v c kt qu trong cc my vi cc tnh nng tinh vi v
c o to nn kt qu chnh xc v hiu sut s dng cao.
5/27/2018 bcthtap_5541
5/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
4
Mt s a ch wed ca Sodick:
http://www.sodick.jp
http://www.sodick.org
http://www.sodick.com
http://www.sodick.jp/http://www.sodick.org/http://www.sodick.com/http://www.sodick.com/http://www.sodick.com/http://www.sodick.org/http://www.sodick.org/http://www.sodick.jp/5/27/2018 bcthtap_5541
6/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
5
PHN B: NI DUNG BO CO THC TP
PHN I
TNG QUAN V CNG NGH EDM
Trong na u th k 20, nhu cu v cc vt liu lu mn tng ln khng
ngng cc nc cng nghip pht trin. Nhng vn l gia cng nhng
vt liu bng cng ngh thng thng th rt kh khn, nhiu khi khng
thc hin c. S xut hin ca cc my CNC EDM (Electrical Discharge
Machining) nhanh chng thay i vic sn xut cng nghip. Cc ng
cong c thc hin d dng nh ng thng, cc cu trc phc tp 3 chiu
cng d dng thc hin, v mt lng ln cc thao tc do con ngi thc
hin c gim thiu.
1.1.Nguyn l gia cng tia la in ( EDM)
http://vi.wikipedia.org/w/index.php?title=S%E1%BA%A3n_xu%E1%BA%A5t_c%C3%B4ng_nghi%E1%BB%87p&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=S%E1%BA%A3n_xu%E1%BA%A5t_c%C3%B4ng_nghi%E1%BB%87p&action=edit&redlink=15/27/2018 bcthtap_5541
7/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
6
V nguyn l gia cng th y l hiu qu n mn vt liu gy ra bi s
phng in. Khi cc tia la in c phng ra, vt liu trn b mt phi b
ht i bi mt qu trnh in-nhit thng qua s nng chy v bc hi kim
loi - l qu trnh gia cng bng tia la in gi tt l gia cng EDM
(Electrical Discharge Machining).
Cho n nay qu trnh EDM c pht trin kh rng ri cc nc pht
trin. Nhiu gam my hot ng trong lnh vc EDM c sn xut vi
nhiu kiu khc nhau phc v nhng mc ch khc nhau. N a quy v
2 dng sau:
1.1.1.Gia cng tia la in dng in
cc nh hnh
Gi tt l phng phpxung nh hnh.
in cc l mt hnh khng gian bt k, n s
in hnh ca mnh ln phi to ra lng khun thng dng to hnh nhngchi tit c l nhng khng thng.
5/27/2018 bcthtap_5541
8/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
7
1.1.2. Gia cng tia la in bng ct dy
Ct dy tia la in l mt hnh thc c bit ca gia cng tia la in. imkhc nhau c bn gia ct dy tia la in v xung in (gia cng bng in
cc thi) l thay v s dng nhng in cc thi c hnh dng phc tp th
trong WEDM in cc l mt si dy c ng knh t 0,1 0,3mm. Dy
ny c cun lin tc v chy theo mt bin dng cho trc, ct c b
mt 2D v3D phc tp.
Trong qu trnh gia cng, dng c v chi tit l hai in cc, trong dng
c l catt, chi tit l ant ca mt ngun in mt chiu c tn s 50
500kHz, in p 50 300V v cng dng in 0,1 500A. Hai in cc
ny c t trong dung dch cch in c gi l cht in mi.Khi cho hai in cc tin li gn nhau th gia chng c in trng. Khi
in p tng ln th t b mt cc m c cc in t phng ra, tip tc tng
in p th cht in mi gia hai in cc b ion ha lm cho chng tr nn
dn in, lm xut hin tia la in gia hai in cc.
5/27/2018 bcthtap_5541
9/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
8
Nhit vng c tia la in ln rt cao, c th t n 12.0000C, lm
nng chy, t chy phn kim loi trn cc dng. Trong qu trnh phng
in, xut hin s ion ha cc mnh v to nn p lc va p rt ln, y
phoi ra khi vng gia cng.
Ton b qu trnh trn xy ra trong thi gian rt ngn t 10-4 n 10-7s. Sau
mch tr li trng thi ban u v khi in p ca t c nng ln n
mc phng in th qu trnh trn li din ra im c khong cch
gn nht.
Phoi ca qu trnh gia cng l nhng git kim loi b tch khi cc in cc
v ng c li thnh nhng ht nh hnh cu v b y ra khi vng gia
cng bng lung dung mi c p sut cao. Khi cc ht ny b y ra khi
vng gia cng, khe h gia hai in cc ln ra v s phng in khng cn
na. tip tc gia cng cn di chuyn hai in cc li gn nhau v qu
trnh lp li lin tc. Gia cng bng tia la in, EDM (Electrical Discharge
Machining) l mt qu trnh tch kim loi bng mt tia la in trong thi
gian rt ngn vi cng dng in ln gia dng c ct v chi tit.Qutrnh EDM c th so snh vi mt phn thu nh ca mt tia st va vo mt
b mt to nn vng tp trung nhit ln lm nng chy b mt gia cng.
1.2. Bn cht vt l
t mt in p gia in cc v phi.- Khng gian gia in
cc v phi phi c in y bi mt cht in mi.- Cho 2
in cc tin li gn nhau, n mt khong cch ( no thxy ra s phng tia la in, xut hin mt dng in tc thi.
Nu 2 in cc chm nhau th s khng c tia la in m s
sy ra ngn mch c hi cho qu trnh gia cng.- Nu khe h
qu ln th s khng th xy ra s phng tia la in iu
5/27/2018 bcthtap_5541
10/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
9
lm gim nng sut gia cng.- c th lm pht sinh tia la
in, mt iu khng th thiu c l mt thi gian ngn sau
khi c dng in chy qua 2 in cc th phi ngng cung
cp nng lng. n gin ngi ta dng b pht xung RC nh
trn cung cp xung rng ca.
1.3. Cc thng s cng ngh ca EDM.
1.3.1. c tnh v in ca s phng tia la in.
Cc c tnh v in c nhn ra da vo cc c tnh thi gian ca s
phng tia la in. Cc c tnh ny chnh l cc thng s iu chnh quan
trng nht ca qu trnh gia cng.
Mi my pht ca thit b gia cng tia la in u c mt nhim v l cung
cp nng lng lm vic cn thit. My pht xung hin i ca mt thit b
gia cng tia la in l mt my pht xung tnh. y nng lng c iu
khin bng in t nhng khng c yu t b. Nguyn l tc dng ca my
pht xung tnh thc hin trc ht thng qua s pht trin ca Transistormnh v cc sn phm in t hin i. My pht xung tnh c u vit ln
linh hot ca cc thng s iu chnh. Qua mi trng hp gia cng
c th c gii quyt di quan im l in cc t mn nht v cht lng
b mt l ti u. mun vy cc thng s ca qu trnh gia cng phi c
iu chnh cho ph hp.
1.3.2. Cc thng s iu chnh. in p nh la Ui: y l in p cn thit dn ti s
phng tia la in. N cung cp cho in cc v phi khi my
pht c ng in, gy ra s phng tia la in t chy
5/27/2018 bcthtap_5541
11/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
10
vt liu. in p nh la Ui cng ln th phng in cng nhanh
v cho php khe h phng in cng ln.
Thi gian tr nh la td: l thi gian gia lc ng in
my pht v lc xy ra phng tia la in. Khi ng in my
pht lc u cha xy ra iu g. in p duy tr gi tr ca
in p nh la Ui, dng in bng 0. Sau mt thi gian tr td
mi xy ra s phng tia la in. Dng in t 0 vt ln Ie.
in p phng tia la in Ue: khi bt u phng tia la in
th in p tt xung t Ui n Ue. y l in p trung bnh
trong sut thi gian phng tia la in. Ue l mt hng s vt l
ph thuc vo cp vt liu in cc/phi. Ue khng iu chnh
c.
Dng phng tia la in Ie:l gi tr trung bnh ca dng in
t khi bt u phng tia la in n khi ngt in. Khi bt u
phng tia la in dng in tng ln t 0 n gi tr Ie, km
theo s t chy. Ie nh hng ln nht n lng ht vt liu, mn in cc v cht lng b mt gia cng. Nhn chung Ie
cng ln th lng ht vt liu cng ln, nhm b mt cng
ln nhng mn in cc gim.*Dng in v din tch b mt
b n mn: Mt dng in (A/mm2) s sinh ra lng nhit ln
lm qu nhit in cc v gy mn in cc nhanh hn. Do vy
gia cng mt vng nh cn chn dng in nh v ngc li.
Nh vy, khi gia cng ch c mt in cc hay c nhiu in cc
thay th th phi ch la chn dng in cho ph hp sao
cho n cho php t c lng ht vt liu ln nht c th t
5/27/2018 bcthtap_5541
12/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
11
c trong khi vn duy tr nhn bng v mn in cc
trong gii hn yu cu.
ko di xung ti:l khong thi gian gia hai ln ng ngt
ca my pht trong cng mt chu k phng tia la in. N bng
thi gian tr (td) v thi gian phng tia la in ie: ti = td + te.
ko di xung ti nh hng n nhiu yu t quan trng c lin quan trc
tip n cht lng v nng sut gia cng.Cc yu t b nh hng:- ti nh
hng ln n lng ht vt liu: thc nghim cho thy khi gi nguyn
dng in Ie v khong cch xung to, nu tng ti th ban u Vw tng nhng
ch tng n gi tr cc i ti nht nh no sau Vw gim i, nu vn
tip tc tng ti th nng lng phng in khng cn c s dng thm na
ht vt liu phi m n li lm tng nhit ca cc in cc v dung
dch in mi.
Khong cch xung to:l thi gian gia hai ln ngt-ng ca
my pht xung thuc 2 chu k phng in k tip nhau, to cn
c gi l ko di ngh ca xung.Cng vi t l ti/to, to cnh hng rt ln n lng ht vt liu. Khong cch to cng
ln th lng ht vt liu Vw cng nh v ngc li.Phi gi to
nh nh c th c n c th t mt lng ht vt liu ti
a. Nhng khong cch xung to phi ln c thi gian
thi in ho cht in mi trong khe h phng in. Nh s
trnh c li ca qu trnh nh to h quang hoc dng ngn
mch. Cng nh trong thi gian ca khong cch xung dng
chy s y cc vt liu b n mn ra khi khe h phng
in.Do vy, tu thuc vo kiu my v trng hp gia cng c
th m la chn to, ti ph hp thng qua t s ti/to :
5/27/2018 bcthtap_5541
13/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
12
Khi gia cng rt th chn: ti/to > 10
Khi gia cng th chn: ti/to = 10
Khi gia cng tinh chn: ti/to = 5
Khi gia cng rt tinh chn: ti/to < 5 (thng chn = 0,4).
Khe h phng in: cho ti y, ta c rt nhiu cc thng s iu chnh
nh: I, ti, to, U.... m chng ch tc ng ln s phng ta la in. d
kin c lng ht vt liu t u n cui sau mt s ln phng tia la
in th vn l phi duy tr khe h v mt chiu rng ti u. Qu trnh
gi l s iu chnh khe h phngin. l cch m bo chc chn
rng ic cc tip tc n xung thm nhp vo phi.Trn my xung, vic
o khe h ( c thc nghim gin tip thng qua vic o Ue. Ue l mt i
lng in chnh xc khi in cc tin gn n phi, Ue tng th khe
h cng tng. duy tr mt chiu rng khe h phng in l hng s th
tng ng vi n l mt gi tr danh ngha ca Ue. Trong qu trnh gia cng,
do in cc v phi b n mn lm cho ( ln ln, iu chnh th Ue c
o lin tc v c so snh vi gi tr danh ngha. Thng thng trong giacng, ngi vn hnh my chn I, ti, to, Ui ph hp vi yu cu nng sut
v cht lng b mt, lc h iu khin s t ng iu chnh ( cho ph
hp vi I v Ui).
1.4. Gia cng EDM c th c phn loi nh sau:
Gia cng xung nh hnh EDM (Die Sinking EDM hay Ram-
EDM) Gia cng EDM bng dy ct (Wire-cut EDM hoc Wire EDM)
Gia cng vi EDM (Micro EDM)
Khoan EDM (EDM drilling)
5/27/2018 bcthtap_5541
14/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
13
1.5. Cc trc cn bn ca my EDM
My ct EDM c tng cng 05 trc c iu khin h trc ta my da
trn 2 tiu ch l trc chnh ca my v bn my.
Trc X : chuyn ng (+) theo chiu tay tri
sng tay phi
Trc Y : chuyn ng (+) xa ngi thao tc
Trc Z: thng ng, chiu (+)l hng ln
trn
Trc U : trc // vi trc X( l trc bn my)
chiu (+)t tri sang phi
Trc V: trc // vi trc Y( l trc bn my) chiu (+) xa ngi thao tc.
5/27/2018 bcthtap_5541
15/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
14
PHN 2:
TM HIU V MY CT XUNG ( DIE SINKING EDM)
http://greub-machines.com/pmn-sodick-sink-e.htmlhttp://greub-machines.com/pmn-sodick-sink-e.html5/27/2018 bcthtap_5541
16/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
15
NGUYN L GIA CNG MY CT XUNG EDM
5/27/2018 bcthtap_5541
17/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
16
H thng gia cng tia la in (Electrical Discharge Machining -EDM) bao
gm c hai b phn ch yu: my cng c v ngun cung cp in. My
cng c gn in cc nh hnh (ng vai tr l dao) v in cc tin ti b
mt chi tit gia cng sinh ra mt l chp hnh hnh dng ca dng c.Chi tit
gia cng lp trn bn my cng c, cn in cc th gn vi u my. Mt
ng c servo AC hoc xylanh thy lc iu khin in cc theo phng
thng ng v duy tr mt v tr thch hp ca in cc so vi chi tit giacng.
Ngun nng lng cung cp sn sinh ra mt tn s cao, to ra mt lot tia
la in gia in cc v b mt chi tit v bc i mt lp kim loi bi s n
mn ca nhit v s ha hi.V tr ny c iu chnh mt cch t ng
vi s chnh xc cc k nh h thng servo v ngun cung cp. Trong qu
trnh vn hnh my thng thng in cc khng bao gi chm b mt chi
tit, gia chng c mt khe h phng in nh.C chi tit v in cc u
ngm chm trong dung dch in mi. Dung dch ny ng vai tr nh cht
cch in iu khin s phng tia la in. Trong gia cng EDM cht
in mi cng thc hin chc nng ca mi trng lm ngui v lm gim
5/27/2018 bcthtap_5541
18/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
17
nhit cc k cao trong khe h phng
in. Quan trng hn, dung dch in
mi c bm vo theo khe h hnh
cung y i nhng ht b xi mn
gia chi tit v in cc.
Mt s hnh nh v u cc:
5/27/2018 bcthtap_5541
19/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
18
Mt s dng my ct xung EDM ca SODICK nh C32, AP1L, AD3L,
AG75L...
Mt s thng s v my C32
Hnh trnh dch chuyn cc trc
X/Y/Z
300x250x150 mm
Hnh trnh dch chuyn cc trc
U/V
35x45mm.
Khoang lm vic ca my 450x300 mm
Khi lng vt gia cng ti a 50kg
Trng lng in cc ti a 20kg.
Kch thc bn 600 x 400mm
Kch thc thng cha du 925 x 555 x 300
H iu khin LMX32 hot ng trn nn
Window XP
Mn hin th cm ng TFT 15"
Phn mm h tr gia cng LN Assit
Khi lng my 2500kg
5/27/2018 bcthtap_5541
20/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
19
C32 dng my ct xung EDM
mi nht ca Sodick vi
truyn ng ng c tuyn
tnh th h th 5 c thit k
nh gn, C32 s dng h iu
khin LMX32 hot ng trn
nn Window XP vi mn hin
th cm ng TFT 15". Phn
mm h tr gia cng LN Assit
gip ngi vn hnh d dang
to cc chng trnh NC (vi
cc iu kin gia cng v ch
b ti u) t mi bi ton
sn phm.
C32 l my EDM u tin ng dng cng ngh truyn tn hiu serial siu tc1Gbit/giy cho h thng iu khin. H thng truyn tn hiu tc cao ny
gip nng cao hiu sut truyn ng, phn hi iu khin servo cng nh
tin cy ca my trong qu trnh gia cng.
H iu khin LMX32 vi h mch "zero wear" gip gim hao mn in
cc graphite di 0.06% trong khi tng tc gia cng ti 20%. Vi tnh
nng ny, C32 gip gim s lng in cc khi gia cng cc l hc. Trong
khi, mt my EDM thng thng i hi t 2-3 in cc cho gia cng th,
gia cng bn tinh v gia cng tinh, C32 c th ch cn n 1 in cc duy
nht. iu ny khng ch gip tit kim thi gian v chi ph sn xut m cn
gim thiu cc sai s gia cng.
MY C32
5/27/2018 bcthtap_5541
21/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
20
C32 cng c trang b cng ngh truyn ng ng c tuyn tnh tin tin
ca Sodick, gip trc Z c th t tc dch chuyn cao ti 1.400"/pht v
gia tc trng trng ti 1.2G. Vi tc dch chuyn trc Z cao gip t ro
ra hiu ng bm y phoi ra khi cc hc gia cng; nh ngi s dng
khng cn s dng vi xi m vn m bo c cht lng gia cng n
nh nht.
Sodick l nh sn xut hng u trong lnh vc my gia cng tia la in vi
s lng hn 50.000 my bn ra trn ton th gii. Model C32 c tin
tng s l sn phm t ph trong chin lc "ton cu ha my EDM" ca
Sodick .
5/27/2018 bcthtap_5541
22/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
21
PHN 3
MY CT DY EDM( WIRE CUT EDM)
5/27/2018 bcthtap_5541
23/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
22
5/27/2018 bcthtap_5541
24/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
23
Cc nguyn tc c bn ca phng
php ct dy EDM cng ging nh gia
cng xung nh hnh EDM c m t
trn. im khc bit c bn l thay v
s dng nhng in cc c hnh dng
phc tp, trong ct dy EDM in cc
5/27/2018 bcthtap_5541
25/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
24
l nhng si dy c hnh dng n gin, ng knh t 0.006-0.012. Dy
thng s dng l dy ng.Thay v s dng cht in mi nh trong gia
cng xung nh hnh EDM th trong ct dy EDM li dng nc ion ha.
Nc y c tc dng lm mt v loi b cc ht xi mn cng nhanh cng
tt.Trong qu trnh ct nc c nh nhng chy qua khng lm chch
hng cc dy.
EDM wirecut machine
Diefluid Centre (ct p thu lc)pressure: 6bar
Controller
DiefluidCentre
Table
WireCenter
Sng phu
5/27/2018 bcthtap_5541
26/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
25
Wire Center (qun dy) c ng knh: 0.2mm
Machining Center (max. table size: x-300mm y-300mm z-200mm)
Controller system
5/27/2018 bcthtap_5541
27/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
26
DATA ANALYSIS
NC code programming: y l 1 on chng trnh vit gia cng
chi tit.
L 0303;
H1=0.131;
E3501 F19.2 M20 H1 0.131;
M80;
M82;M84;
G90;
G40;
G00 X0 Y0;
G02 X10 Y0;
G01 X10 Y5;G01 X20 Y5;
G01 X20 Y10;
G01 X10 Y10;
G01 X10 Y15;
5/27/2018 bcthtap_5541
28/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
27
G02 X0 Y 15;
G01 X0 Y0;
M00
M02
Mt s dng my ct dy EDM ca SODICK: AD325L,AP200L, AP450L,
EXC100L, AQ237L, TW423, TW533.
Gii thiu v my ct dy EDM TW
Model: TW-423, TW-533
Tng quan
Kiu lm vic bn chm (submersible worktable)
Thn my t gang hp kim MEEHAMITE, kh ng sut d, m bo
thn my cng vng v chnh xc cao
S dng ngun cp AC c tr khng thp, m bo gia cng nhanh v
chnh xc
Mn hnh th hin hnh nh lp th trong qu trnh gia cng
Kh nng ct dc nghing ti a 15o
http://www.dbm.com.vn/products/images/Maycongcu/maycnc/xungdien/catdayEDMTW2.jpg5/27/2018 bcthtap_5541
29/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
28
H thng dn ng vi ng c servo, bng my tuyn tnh v trc
vt me
My trc khi xut xng c kim tra chnh xc bng cc thit
b laser
Thng s k thut
Thng s k thut TW-423 TW-533
Phng php gia cng Loi bn chm Loi bn ch
Kch thc thng lm vic 850x660x430
mm
950x760x49
mm
Kch thc phi ti a 640x490x300
mm
740x590 mm
Trng lng phi ti a 650 kg 750 kg
Hnh trnh trcXxY 420x270 mm 520x370 mm
Hnh trnh trcZ 300 mm 300 mm
Hnh trnh trcU, V 50 mm 50 mm
Motor dn ng cc trcXYZUV ng c AC
Servo
ng c A
Servo
Tc di chuyn ca bn lm vic 4000 mm/pht 4000 mm/ph
ng knh dy ct 0.1-0.3
mm
0.1-0.3
mm
cng dy ct 200-2400 gf 200-2400 gf
Tc ct cc i (dy ng 0.3 mm,
ct AC)
255 mm/pht 255 mm/ph
5/27/2018 bcthtap_5541
30/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
29
Tc di chuyn dy 0-15 m/pht 0-15 m/ph
nhm b mt tt nht Ra 0.28m Ra 0.28m
Gc cn ti a 15o (tychn 22.5o)
15o (tchn 22.5o
Trng lng ti a ca cun dy 6 kg 6 kg
Trng lng my 2650 kg 3000 kg
H thng lc
Phng php lc: lc giy
Th tch thng nc: 650 lt
B lc x l nha trao i ion: 15 lt
Kim sot dn in: t ng
iu khin nhit nc: ty chn
Ngun cp
Loi mch: cng sut Transitor MOS
On time: 10 bc
Off time: 20 bc
Cng sut: ct AC
Mt vi thng s ca my AD325L:
5/27/2018 bcthtap_5541
31/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
30
5/27/2018 bcthtap_5541
32/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
31
Mt s sn phm sau khi ct bng my EDM:
5/27/2018 bcthtap_5541
33/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
32
SO SNH GIA CNG XUNG NH HNH V CT DY
Gia cng bng in cc thi ngi ta s dng du lm cht in
mi th trong WEDM li dng nc kh khong.
Khi gia cng bng in cc thi, s phng in xy ra gia mt
u in cc vi chi tit gia cng cn khi gia cng bng dy ct
th s phng in xy ra gia mt bn dy ct vi chi tit gia
cng .
Vng phng in khi gia cng bng in cc thi bao gm mt
u v gc ca in cc. Cn vng phng in khi gia cng bng
dy ct ch bao gm mt 180o ca dy cc khi n tin n ct chi
tit gia cng.
U IM
Bi v EDM n mn kim loi bng vic phng tia la in thay cho cc dng
c ct gt to phoi nn cng vt liu khng tr thnh nhn t quyt nh
xem vt liu c th gia cng bng EDM hay khng. Cc in cc kim
loi hoc than ch mm c th gia cng cc loi thp dng c ti hoctungsten carbide (cacbt vonfram). y l mt trong nhng li ch hp dn
ca vic s dng phng php EDM. C th nhit luyn chi tit trc ri
sau c th gia cng bng EDM. iu ny loi b ri ro ca nhng h hi
v bin dng c th bin nhng chi tit t tin thnh ph liu trong khi x
l nhit.
NHC IM
Phi v dng c (in cc) u phi dn in
V tc ct gt thp nn phi trc gia cng EDM thng phi
gia cng th trc. Do vng nhit ti vng lm vic cao nn
gy bin dng nhit.
5/27/2018 bcthtap_5541
34/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
33
PHM VI NG DNG
Gia cng cc l c ng knh nh 0,15mm ca cc vi phun
cao p c nng sut cao (t 15 n 30s/chic), gia cng l su t
60mm cho sai s 5m. Cc l 0,05mm 1mm vi chiu su
ln nh cc l lm mt trong cnh tuabin lm bng hp kim siu
cng, cc l su vi t s chiu di trn ng knh ln n 67.
Ly cc dng c b gy v kp trong chi tit (bulng, tar)
Gia cng khun mu v cc chi tit cn chnh xc cao bng
vt liu hp kim cng.
CHNH XC GIA CNG
chnh xc ph thuc vo nhng yu t sau :
chnh xc ca my.
Dng c.
Khe h phng in.
nhm b mt ph thuc vo nng lng mt ln phng
in.Gia cng kim loi c cng khng gii hn (v da vo
tnh cht vt l).
5/27/2018 bcthtap_5541
35/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
34
PHN 4:
B IU KHIN CHNH TRONG MY CT EDM
4.1.H thng servo AC
H thng Servo AC l mt h
thng iu khin vng kn
c gn thm encoder ly
tn hiu hi tip nh tc , v
tr. Dng iu khin o
lng c kh, p ng rt chnh
xc cc yu cu v v tr v tc
c lp trnh trc. . Nuc bt k l do no ngn cn
chuyn ng quay ca ng c, c cu hi tip s nhn thy tn hiu ra cha
t c v tr mong mun. Mch iu khin tip tc chnh sai lch cho ng
c t c im chnh xc.
My EDM s nhn ch th nh v( Drive motor servo AC signal) t chng
trnh NC. ng c ch ng (
Drive motor) chy s vng
tng ng quay trc dch
chuyn. Khi v tr cn thit
ti thit b phn hi(feedback
5/27/2018 bcthtap_5541
36/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
35
device) gi tn hiu ti b iu khin kt thc lnh.
Mt lnhNCthc hin bn trong b iu khin s bo cho m t ch ng
quay ng s vng cn thit ko theo trc vitme bi quay s vng tng ng.Ti lt mnh vitme bi ko theo chuyn ng thng ca bn my hoc tay
gn in cc. Thit b phn hi u kia ca vitme bi cho php kim sot
kt thc lnh ng khi s vng quay cn thit c thc hin.
Servopact(b driver servo): b ny c chc nng iu khin ng c servo.
Mt s hnh nh v b Servopact:
http://ltk52-humg.com/blog/?tag=cnchttp://ltk52-humg.com/blog/?tag=cnc5/27/2018 bcthtap_5541
37/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
36
Cc my CNC EDM hin ti u s dng AC servo dn ng cc trc,
cc i c hn th xi DC servo.Ngi ta s dng ng c ac servo v
momen n nh trong di tc rng, tc cao, t n, ko yu cu bo tr ,
c th ch to cng sut ln.
Thng thng cc my ct EDM u c t 45 trc ( X/Y/Z/U/V ) tng
ng l s ng c servo v drive. M drive s iu khin s di chuyn ca
mt trc.
AC servo motor dc iu khin thng qua driver. Driver thng c 2 cch
iu khin:
Dng tn hiu analog, p cp vo thng l -10V +10V
Dng tn hiu xung.
to xung, c th s dng IC 555
S chn:
Chn 1: ni xung t ly dng cung cp cho IC.
http://tudiencongnghe.com/Special:Search/DChttp://tudiencongnghe.com/Special:Search/DC5/27/2018 bcthtap_5541
38/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
37
Chn 2: ng vo ca 1 tn s so p, mch so p dng cc n bn dn
thun (mc p chun l 2*Vcc/3).
Chn 3: Ng ra.
Chn 4: dng lp nh mc trng thi ra. Khi chn 4 ni mass th ng
ra mc thp, cn khi chn 4 ni ln mc p cao th trng thi ng ra
tu theo mc p chn 2 v 6.
Chn 5: dng lm thay i mc p chun trong IC theo VR hay R
ngoi cho ni mass. Tuy nhin trong cc mch ng dng thng chn
s 5 ni mass qua 1 con t t 10nF -100nF tc dng lc b nhiu cho
mc p chun n nh.
Chn 6: ng vo ca 1 tn so p khc, mch so snh dng cc
Transistor ngc Vcc/3.
Chn 7: c th xem nh 1 kho in.
Chn 8: Cp ngun nui cho IC. Ngun nui cp cho IC khong t
+5V n +15V , ti a l =18V.
Mch iu khin ng c servo i hi mt mch in t chnh xc quay
trc ra ca n.Mt IC 555 c th cung cp cc xung cn thit cho servo.
5/27/2018 bcthtap_5541
39/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
38
Khi hot ng, IC 555 sinh ra mt tn hiu xung c chu k nhim v khc
nhau iu khin hot ng ca servo. Chnh Vnk nh v servo. VIC555 c th d dng to xung rt di v rt ngn nn servo c th hot ng
ngoi v tr bin thng thng.
Khi servo gp vt cn v ku lch cch ta phi ngt ngun ngay, nu khng
cc bnh rng bn trong s b trn.
5/27/2018 bcthtap_5541
40/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
39
5/27/2018 bcthtap_5541
41/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
40
4.2.Mt s h thng mch trong my EDM
5/27/2018 bcthtap_5541
42/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
41
5/27/2018 bcthtap_5541
43/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
42
5/27/2018 bcthtap_5541
44/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
43
KT QU THU C SAU THC TP
Sau khi kt thc thc tp, hc tp v nghin cu h thng my ct EDM
cng cc anh, cc ch trong cng ty.Nh s gip ch bo tn tnh ca ban
lnh o v cc ch,cc anh trong cng ty em tip thu hc hi,rt ra nhiu
bi hc qu bu:
Bit c qu trnh hot ng ca, nguyn l hot ng v ng dng ca cc
my ct EDM nh my ct xung EDM, my ct dy EDM.
Tip cn thc t c vi cng ngh CNC ,mt cng ngh hin i m em
ch c dp c trn sch v, thu thp nhiu ci mi,cng c li c nhng
g hc.
Hc hi c tc phong cng nghip kinh nghim thc t,ni quy,o c
ngh nghip v c bit l tnh cn thn trong ngnh in.
Tinh thn cu tin,tnh cch trung thc,cn c,t m v trch nhim trong
cng vic.Tt c nhng iu gp phn hon thin bn thn em c th tr thnh
ngi k s tt.
5/27/2018 bcthtap_5541
45/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
44
LI CM N
Trong qu trnh thc tp ti Cng ty VPD Sodick em may mn c c
hi c i kh nhiu khu cng nghip nh Bc Thng Long, Quang Minh ,
Phc in v c vo cc xng sn xut ca cc cng ty ln nh
Canon, Toho, Brother,Vin Cng Ngh B Quc Phng. Qua gip em
hiu bit thm v lnh vc in c ng dng trong i sng, c va
chm v lm vic trong mi trng thc t, c nhiu ci b ng, nhng qua
em hc hi c nhiu kinh nghim cho bn thn. Nhng kinh nghim
hc hi c vi nhng kin thc trn gh nh trng s gip ch rt nhiu
cho em sau khi tt nghip.
c c kt qu , em xin trn thnh cm n ban lnh o, cn b,
cc anh ch lm vic ti Cng ty VPD Sodick to iu kin v gip
em hon thnh tt t thc tp ca mnh.
Em xin trn thnh cm n thy gio DUY PH, ging vin Trng
i Hc Cng Nghip H Ni, l gio vin hng dn em trong qu trnh i
thc tp v vit bo co thc tp.
Xin trn trng cm n!
5/27/2018 bcthtap_5541
46/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
45
5/27/2018 bcthtap_5541
47/47
Bo co thc tp GVHD: Duy Ph
SVTH: Lng Pht Ngc Lp: in 1_K1
46
NHN XT CA GIO VIN HNG DN THC TP
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..................................................................................................................... ................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..................