Khoa c kh- B mn CNCTM n tt nghip
CHNG 1:TM HIU CHUNG V TI.
I/ Khi nim chung v my nng chuyn.1. Cng dng v phn loi.My nng
chuyn l cc loi my cng tc dng thay i v tr ca i tng cng tc nh thit b
mang vt trc tip nh mc treo hoc thit b mang vt gin tip nh gu ngom,
nam chm in, bng, gu v.v..cn c vo chuyn ng chnh, my nng chuyn c chia
ra lm hai nhm ln: my nng v my vn chuyn lin tc.My nng ch yu phc v cc
qa trnh nng vt th khi, cn my vn chuyn lin tc phc v cc qu trnh chuyn
vt liu vn, ri trong mt phm vi khng ln.c im lm vic cc c cu ca my nng
l ngn hn, lp i lp li v c thi gian dng. Chuyn ng chnh ca my l nng h
vt theo phng ng, ngoi ra cn mt s cc chuyn ng khc dch chuyn vt trong
mt phng ngang nh chuyn ng quay quanh trc my, di chuyn my, chuyn ng
lc quanh trc ngang. Bng s phi hp cc chuyn ng, my c th dch chuyn vt
n bt c v tr no trong khng gian lm vic ca n.Cc my nng ch c mt chuyn
ng nng h c gi l my v thit b nng n gin, v d nh kch, ti, palng, bn
nng, sn thao tc v.v.. loi c t hai chuyn ng tr ln gi l cn trc. Ngoi
hai loi k trn cn c mt s loi my nng chuyn dng khc c xp vo nhm ring
nh thang my, ging ti( dng trong khai thc m), thit b xp d. Theo cu
to v nguyn tc lm vic, chia cn trc ra cc loi sau: Cu trc; Cng trc;
Cn trc thp; Cn trc quay di ng; Cn trc ct bum v cn trc ct quay; Cn
trc chn v cn trc ni; Cn trc cp.My vn chuyn lin tc vn chuyn vt liu
mt cch lin tc, theo tuyn nht nh. Khi lm vic, qu trnh vn chuyn, cht
v d ti c tin hnh mt cch ng thi.My vn chuyn lin tc dng vn chuyn vt
liu, sn phm, bn thnh phm v.v.. vi c ly khng ln trong phm vi mt nh
my, dy truyn sn xut, cng trng, kho bi, nh ga, bn cng, bi khai
thc.Cn c vo nguyn l lm vic, my vn chuyn lin tc c chia thnh hai loi:
my vn chuyn lin tc bng c kh v my vn chuyn lin tc bng thu lc hay kh
nn.2. Cc thng s c bn ca my nng. Sc nng Q( tn, KN) l trng lng ln nht
ca vt nng m my c th nng c trng thi lm vic nht nh no ca my( tm vi
cho trc, v tr phn quay ca my v.v..); Tm vi R(m) l khong cch theo
phng ngang t tm thit b mang vt n trc quay ca my. tm vi ch c cc cn
trc c tay cn; Momen ti MQ (tm, KNm) l tch s gia sc nng v tm vi.
Momen ti c th l khng i hay thay i theo tm vi; Chiu cao nng H(m) l
khong cch t mt bng bn my ng n tm thit b mang vt v tr cao nht. Vi cc
cn trc c tay cn th chiu cao nng thay i ph thuc vo tm vi; Khu L(m) l
khong cch theo phng ngang gia ng trc ca hai ng ray m trn my di
chuyn; ng c tnh ti trng l th m t mi quan h gia sc nng, tm vi v chiu
cao nng; Cc thng s ng hc bao gm cc tc ca cc chuyn ng ring r trn my:
Tc chuyn ng tnh tin ln xung ca vt nng vn (nng vt), vh (h vt), m/s;
Tc di chuyn ca my trn mt phng ngang vdc, m/s; Tc quay ca phn quay
quanh trc thng ng ca my nq, vg/ph; Thi gian thay i tm vi T, s l
khong thi gian thay i tm vi t tm vi nh nht Rmin n tm vi ln nht
Rmax. i khi ngi ta cho tc thay i tm vi trung bnh.3. Mt s my v thit
b nng chuyn thng dng.a. Cc my nng cng dng chung.- Cu trc. Cu trc-
Cn trc quay.
QL = constQLLmaxQL T Cn trc ct quay Cn trc ct c nh
TL Q Cn trc vi vng quayb. Cc my vn chuyn lin tc.- Bng ti. bS0
S1S2 S3S4S5S6S7
- Xch ti.
- Gung ti. - Bng truyn con ln.
Dn ng bng xch
Dn ng bng bnh rng nn
Dn ng bng ai trn
My chuyn qun tnh.
- My chuyn kiu vt.
4. Pa lngL loi thit b nng c dy cun. Thng c treo trn cao nn cn
kch thc nh.C th phn lm 2 loi: pa lng tay v pa lng in.Pa lng tay:c
im chung loi ny l u dng xch lm dy nng v dn ng bnh ko. thu gn kch
thc dng cc gii php:- Truyn cng sut thnh 2 hoc 3 dng- Trc b dn lp
trn trc dn (lp lng khng)- S dng vt liu tt ch to.Xch koXch nngBnh
koan ton
Pa lng in: thu gn kch thc cng s dng cc gii php nh palng tay. Dy
nng l cp hoc xch. Cc b truyn l bnh rng thng hoc bnh rng hnh tinh.
Phanh s dng l loi phanh ma st nhiu a, loi thng ng. C th kt hp thm
phanh t ng nng cao an ton, khi phanh in t s c tc dng thng qun tnh
cc chi tit. ng c intangkhp nihp sphanh aI IIIIIIV cppIIIIIIIVs
rngz2/z1 = 50/14z4/z3 = 58/29z6/z5 = 42/15z8/z7 = 33/13Cc b phn cn
c ch to chnh xc m bo kh nng lm vic ca palng l v hp ca v trc dn. V
hp c cc l hp v thnh hp vi v tr tng quan xc inh cn c ch to m bo c th
lp cc trc v cc chi tit khc ln n theo ng yu cu thit k. Trong qu trnh
tm hiu v my nng chuyn em thy rt thch chi tit v hp ca palng. N l chi
tit dng hp c phc tp tng i ln ph hp vi mc ca mt n tt nghip ca k s c
kh ch to my, c s ng ca thy hng dn, em quyt nh chn v hp ca palng lm
chi tit thit k cho n tt nghip ca mnh. Cc thng s c bn ca palng in c
chn l: + Ti trng: 2 tn;+ Chiu cao nng: 6m.T bn v lp chung ca chi
tit, sau khi tch ring phn v hp v xc nh cc c tnh k thut cng nh cc
thng s cng ngh cho ton b v hp cng nh tng phn tch ring ca v hp, di s
ch o ca thy hng dn v cho ph hp vi mc v thi gian lm n t nghip, em
chn thit k cng ngh 3 phn cui ca v hp cho ti tt nghip ca mnh.
CHNGII: THIT K CNG NGH.
Ni dung vic thit k cng ngh bao gm:1- Phn tch chc nng lm vic ca
chi tit;2- Phn tch tnh cng ngh trong kt cu ca chi tit;3- Xc nh dng
sn xut;4- Chn phng php ch to phi;5- Lp th t cc nguyn cng, cc bc( v
s g t, k hiu nh v,kp cht, chn my, chn dao, v k hiu chiu chuyn ng ca
dao, ca chi tit); 6- Tnh lng d cho mt b mt v tra lng d cho cc b mt
cn li;7-Tnh ch ct v tra theo s tay cng ngh ch to my cc nguyn
cng;8-Tnh thi gian gia cng c bn cho tt c cc nguyn cng. S liu ny l c
s xc nh cc ch tiu kinh t k thut ca quy trnh cng ngh.I/. Phn tch
chung:+ Phn tch chc nng, iu kin lm vic ca chi tit.Da vo bn v chi
tit ta thy v hp palng l chi tit dng hp. Chc nng chnh ca v hp l dng
lp cc b phn khc ca palng nh mt, h thng truyn ng bnh rng bao gm cc
vng bi, cc trc v cc bnh rng, h thng phanh v cc c cu iu khin ni
chung. Ngoi ra n cn c chc nng che chn v bo v cc b phn cng nh kt ni
vi cc b phn khc trong c cu vn chuyn. V hp lm vic trong iu kin thng
xuyn c ti trng rung v va p, lm vic khng theo mt chu k nh trc no c,
do kt cu ca v hp cn m bo cng vng c th p ng c yu cu cng tc.Vi hnh
dng v c im ca chi tit nh vy, ta chn vt liu ch to chi tit l gang xm:
GX 15-32 vi cc thnh phn ho hc sau :C = 3 3,7; Si = 1,2 2,5; Mn =
0,25 1,00; S < 0,12; P =0,05 1,00; []bk = 190 MPa; []bu = 320
MPa.+ Phn tch tnh cng ngh trong kt cu chi tit.Nhn chung kt cu ca
chi tit tng i hp l m bo c th ch to phi bng phng php c. Chi tit c cc
gn tr lc m bo cng vng khi lm vic cng nh khi gia cng, chiu dy gn ln
m bo khng b nt khi c. V hp c ghp t 6 phn nh li vi nhau, cc phn ny
cn c lp ghp sao cho m bo ng tm ca cc l chnh. Nhn chung kt cu lp ghp
ca cc phn l tng i hp l v c th d dng gia cng t c chnh xc yu cu. + Xc
nh dng sn xut.Sau khi tnh ton s b khi lng ton chi tit khong 100 Kg,
vi sn lng hng nm l 1000 chic, theo bng 2.6 TL4 ta tra c dng sn xut
l hng lot ln.II. Thit k cng ngh cho tng phn ca v hp. 2.1. Thit k
cng ngh cho chi tit s 4. 2.1.1. Bn v ch to chi tit.
2.1.2.Phn tch chc nng lm vic ca chi tit.Chi tit c chc nng chnh l
trc chnh ca palng v kt ni vi cc phn khc ca v hp. Trn chi tit c mt l
chnh dng lp bi trc v trn vnh c cc l nh v v l bt bu lng. l chnh phi
c gia cng m bo vung gc gia ng tm l v b mt lp ghp theo yu cu. Cc b
mt lp ghp cng cn c gia cng chnh xc sao cho qu trnh lp ghp c thun li
v t cc yu cu k thut ra.2.1.3. Phn tch tnh cng ngh trong kt cu ca
chi tit.Da vo bn v chi tit ta thy nhn chung kt cu ca chi tit l ph
hp vi qu trnh to phi c, m bo chi tit cng vng trong qu trnh gia cng
cng nh qu trnh lm vic, cc mt cn gia cng c phn cch vi cc mt khng gia
cng. v tr ca cc b mt gia cng cng cho php a dng c vo khi gia cng mt
cch d dng. Kt cu ca chi tit cho php qu trnh g t d dng.2.1.4. Chn
phng php ch to phi. *Xc nh phng php ch to phiKt cu ca chi tit khng
phc tp nhng vt liu ca chi tit l gang xm 15x32 nn ta dng phng php c,
ng vi sn xut hng lot ln nn ta chn phng php c trong khun kim loi .
Sau khi c cn c nguyn cng lm sch v ct ba via .* Bn v lng phi ca chi
tit.
* Chn mt phn khun. 2.1.5. Trnh t cng ngh gia cng chi tit. NC1:
Tin th v bn tinh mt A, B, C, mt l 122. NC2: Tin th v bn tinh mt D v
E, tin rnh thot phoi. NC3: Khoan v khot ming 6 l bt bu lng mt pha.
NC4: Khoan v khot ming 6 l bt bu lng pha cn li. NC5: Tin tinh mt B
v C. NC6: Tin tinh mt D v E.2.1.6. S nh v v kp cht, chn my v dao
cho tng nguyn cng.2.1.6.1. Chn chun.Chn chun v s dng chun l mt vn
rt quan trng v n nh hng trc tip n qu trnh cng ngh, nh hng n vic ch
to v s dng g. Chnh v vy chn v s dng chun hp l trong qa trnh gia cng
c mt ngha rt ln, gp phn vo vic nng cao chnh xc gia cng cng nh nng
sut gia cng. V vy vic chn chun phi da theo kt cu c th ca chi tit,
bin php cng ngh trn c s tun theo cc nguyn tc sau:- Chn chun phi xut
pht t nguyn tc 6 im sao cho khng ch ht 6 bc t do cn thit ca mi s
nguyn cng, tuyt i trnh hin tng thiu v sai nh v;- Chn chun sao cho
chi tit gia cng t b bin dng di tc dng ca lc ct v lc kp v phi gim nh
c sc lao ng ca cng nhn;- Chn chun sao cho kt cu g n gin, d ch to v
thun tin khi s dng, to diu kin nng cao nng xut h gi thnh sn phm;Trn
c s ny ta c th chn chun tinh thng nht cho c qa trnh gia cng, t m ta
la chn phng n chun th hp l nht da trn h chun tinh ny i n gia cng
chun tinh.a. Chn chun tinh.Chun tinh l b mt dng lm chun qua gia
cng, khi chn chun tinh cn tun theo nhng li khuyn sau:- Nn chn chun
tinh l chun tinh chnh nh vy th chi tit sau khi gia cng s c v tr tng
t lc lm vic;- Nn ch chun tinh sao cho c tnh trng chun cao;- Nu iu
kin g t v qa trnh cng ngh cho php th nn chn chun tinh l chun tinh
thng nht;Khi chn chun phi m bo hai yu cu sau:+ Chn chun tinh phi m
bo c chnh xc v v tr tng quan gia cc b mt gia cng vi nhau;+ Phi m bo
phn b lng d cho cc b mt s gia cng.Nguyn cng 1: Tin th v bn tinh cc
mt A, B, C, tin v vt mp l 122.- S nh v v kp cht.Chi tit c nh v 5 bc
t do bng cc chu kp ca my tin nh hnh v. Vic kp cht c thc hin nh iu
chnh cc chu kp to ra p lc ln thnh trong ca chi tit. Vic chn chun th
l mt trong ca chi tit khng gia cng s m bo phn b lng d cho cc b mt,
ng thi m bo chnh xc cn thit ca b mt khng gia cng ny vi cc b mt khc
ca chi tit.
- Chn my v dao.+ Chn my.Vi kch thc ng knh ln nht ca chi tit phi
gia cng l 450 mm, ng thi ph hp vi iu kin sn xut ca nc ta hin nay,
chn my gia cng l my tin vn nng 1K625. Cc thng s k thut ch yu ca my
nh sau: ng knh gia cng ln nht: 500 mm; Khong cch hai u tm:
1000-1400-2000 mm; ng knh ln nht ca chi tit gia cng c trn bn dao:
260 mm; Chiu di ln nht tin c trn hai u tm: 930-1330-1930; ng knh ln
nht ca vt lun qua trc chnh: 50mm; ng knh l trc chnh: 52 mm; cn trc
chnh, mooc : N06; S cp tc : 23; Gii hn vng quay: 12,52000 vng/pht;
S cp tc chy dao : 12 cp; Gii hn chy dao : dc 0,074,16 mm/v; ngang
0,0352,08 mm/v; Cng sut ng c: 10 kW; Kch thc my 2812x1216x1349 mm;
phc tp sa cha R: 29.+ Chn dao. .Tin mt u: dng dao tin ngoi thn cong
gn mnh hp kim cng BK8 vi cc kch thc H=25, B =16( Bng 4.4-TL1).. Tin
l: dng dao tin l gn mnh hp kim cng BK8 vi cc kch thc h =20, b =20,
gc nghing chnh = 600( Bng 4.13-TL1).Nguyn cng 2: Tin th v bn tinh
mt D, E, tin rnh thot phoi v vt mp l 122. - S nh v v kp cht.Chi tit
c nh v 5 bc t do: phin t nh v vo mt B gia cng khng ch 3 bc, cht tr
ngn nh v vo mt l chnh khng ch 2 bc. K t nguyn cng ny ta s dng mt l
chnh 122 lm chun tinh thng nht thc hin cc nguyn cng cn li. Vic kp
cht c thc hin nh n kp lin ng kp cht vo mt bch ca chi tit. S nh v v
kp cht nh sau:
- Chn my v dao.Vic chn my v dao nh nguyn cng trn.Ngun cng 3:
Khoan v khot ming 6 l bt bu lng pha mt D.- S nh v v kp cht.Trong
nguyn cng ny ta s dng phin dn c lp cc bc dn, phin dn c nh v trc tip
vo chi tit theo 5 bc t do thng qua cc cht t t vo mt trn D gia cng
ca chi tit khng ch 3 bc v cht tr nh v vo mt l chnh khng ch 2 bc. Do
chi tit l dng i xng nn khng cn khng ch bc t do xoay quanh tm ca chi
tit. C cm chi tit c lp phin dn v bc dn c nh v vo thn g thng qua
phin t t vo mt B khng ch 3 bc t do. Vic kp cht chi tit, phin dn c
thc hin nh bu lng ai c bt cht vo thn g. S nh v v kp cht nh sau:
Vi phng n ny s cho ta ng tm gia cc l bt bu lng vi l chnh l tt hn
c, ng thi m bo c vung gc gia tm cc l bt bu lng vi mt bch lp ghp D.-
Chn my v dng c ct..Chn my:Vi kch thc chi tit nh vy ta c th gia cng
trn my khoan cn 2H52. Cc thng s c bn ca my khoan cn 2H53 nh sau: ng
knh gia cng ln nht : 35 mm; Khong cch t tm trc chnh ti trc my:
3201250 mm; Khong cch t trc chnh ti bn my: 4001400 mm; cn trc chnh
: moc N04; S cp tc : 12; Gii hn vng quay: 252500 vng/pht; S cp tc
cp tc chy dao : 12 cp; Gii hn chy dao : 0,0561,22 mm/vng; Dch chuyn
ngang ln nht ca u khoan: 900mm; Gc quay ln nht ca cn xung quanh trc
thng ng: 3600; Dch chuyn thng ng ln nht ca cn: 700 mm; Dch chuyn
thng ng ln nht ca trc chnh: 300mm; Cng sut ng c chnh: 2,8 kW; Kch
thc my 2240x870x3035 mm; phc tp sa cha R: 29..Chn dao:Chn mi khoan
rut g tra bng 4.41 TL1 bng thp gi P18 ui tr loi ngn vi ng knh d =
12mm, chiu di L = 102mm, chiu di phn lm vic l = 51mm.Nguyn cng 4:
Khoan v khot ming 6 l bt bu lng pha mt B.- S nh v v kp cht.Trong
nguyn cng ny ta s dng phin dn c lp cc bc dn, phin dn c nh v trc tip
vo chi tit theo 5 bc t do thng qua cc cht t t vo mt trn B gia cng
ca chi tit khng ch 3 bc v cht tr nh v vo mt l chnh khng ch 2 bc. Do
chi tit l dng i xng nn khng cn khng ch bc t do xoay quanh tm ca chi
tit. C cm chi tit c lp phin dn v bc dn c nh v vo thn g thng qua
phin t t vo mt D khng ch 3 bc t do. Vic kp cht chi tit, phin dn c
thc hin nh bu lng ai c bt cht vo thn g. S nh v v kp cht nh sau:
Chn my v dao: nh nguyn cng trn.Nguyn cng 5: Tin tinh 2 mt lp ghp
B v C.- S nh v v kp cht. nguyn cng ny, sau khi c cc b mt qua gia
cng, ta s dng b mt lp ghp D v mt l chnh 122 lm cc mt nh v. Phin t t
vo mt D khng ch 3 bc t do, cht cn t la nh v vo mt l chnh khng ch 2
bc t do. Vic kp cht chi tit c thc hin bng n kp lin ng t vo mt bch
lp ghp ca chi tit. S nh v v kp cht c thc hin nh sau:
- Chn my v dao.Chn my v dao nh nguyn cng 1 v 2.Nguyn cng 6: Tin
tinh 2 b mt lp ghp cn li D v E.- S nh v v kp cht.Chi tit c nh v 5
bc t do: phin t t vo mt B khng ch 3 bc t do, cht tr ngn nh v vo mt
l 122 khng ch 2 bc t do. Vic kp cht chi tit vo thn g cng c thc hin
bng n kp lin ng p vo mt bch lp ghp ca chi tit. S nh v v kp cht nh
sau:
- Chn my v dao: Vic chn my v dao nh nguyn cng trn.2.1.7. Tnh lng
d cho mt b mt v tra lng d cho cc b mt cn li.Lng d gia cng c xc nh
hp l v tr s v dung sai s gp phn bo m hiu qu kinh t ca qu trnh cng
ngh v:Lng d qu ln s tn nguyn vt liu, tiu hao lao ng gia cng nhiu ng
thi tn nng lng in, dng c ct, vn chuyn nng . . . dn n gi thnh
tng.Ngc li, lng d qu nh s khng ht i cc sai lch ca phi bin phi thnh
chi tit hon chnh.Trong cng ngh ch to my, ngi ta s dng hai phng php
sau y xc nh lng d gia cng:Phng php thng k kinh nghim.Phng php tnh
ton phn tch.Phng php thng k kinh nghim xcnh lng d gia cng bng kinh
nghim. Nhc im ca phng php ny l khng xt n nhng iu kin gia cng c th
nn gi tr lng d thng ln hn gi tr cn thit.Ngc li, phng php tnh ton
phn tch da trn c s phn tch cc yu t to ra lp kim loi cn phi ct gt to
ra chi tit hon chnh.Trong n ny ch tnh lng d theo phng php phn tch
cho b mt B, cn li l thng k kinh nghim.2.1.7.1. Tnh lng d gia cng
khi gia cng b mt B.Cc bc cng ngh thc hin khi gia cng b mt B: Tin
th; Tin bn tinh; Tin tinh.a) Tnh lng d gia cng ti thiu Zmin.Lng d
gia cng ti thiu theo phng php gia cng ny c xc nh theo cng thc
sau:Zmin = Rzi-1+ Tai-1 + i-1+ i.Trong : Rzi-1: Chiu cao nhp nh t
vi do bc cng ngh st trc li. Tai-1: Chiu su lp kim loi b mt b h hng
do bc cng ngh st trc li. i-1: Sai lch v v tr tng quan v sai s khng
gian tng cng do bc cng ngh st trc li. i: Sai s g t chi tit bc cng
ngh ang thc hin. Bc tin th:Trc bc tin th, b mt gia cng l b mt sau
c. Theo bng 3.2 TL4 ta c cc thng s b mt ca chi tit nh sau:Rz=
200(m); Ta =300 (m).Sai lch khng gian tng cng c xc nh theo cng thc
sau: phi = CV ( cong vnh).Theo bng 3.7 TL4, ta c cong vnh n v ca
phi c dng hp k = 0,7 1 m/ 1 mm chiu di chn k = 1.Suy ra : phi =
1x450 = 450 (m.).- Bc tin bn tinh:Sau bc tin th i lng Ta khng cn
na, ch cn Rz v .Theo bng 3.4 TL4 ta c: Rz = 50 m. cong vnh n v sau
bc nguyn cng u tin ca phi c tra theo bng 3.7 TL4 ta c: k = 0,04. =
0.04x450= 18 (m).- Bc tin tinh.Sau bc tin bn tinh th cng vnh khng
cn na, ch cn Rz. vi cp chnh xc t c l 9 Rz = 20 (m).- Sai s g t c
tnh theo cng thc sau: g2 = c2 + k2 +g2Sai s g thng khng lin quan n
qu trnh g t, do chng thng c tnh c lp, v th c th tnh gn ng: g2 = c2
+ k2.Trong : - c l sai s do chn chun( nh v ); - k l sai s do kp
cht.Sai s k xut hin do bin dng n hi v bin dng tip xc ca cc b mt ca
phi v phin t ca g, sai s kp cht s lm thay i v tr yu cu ca b mt gia
cng. sai s kp cht c gi tr ng bng khong dao ng v tr ca mt t so vi gc
kch thc theo phng ca kch thc gia cng.Sai s do kp cht c xc nh theo
cng thc sau: k = C.Qn. cosTrong : C: h s c trng cho iu kin tip xc,
vt liu v cng ca mt chun ca phi. Q: lc kp cht. : gc gia phng ca lc
kp v phng ca kch thc gia cng.Do bc tin th v bn tinh phng ca lc kp v
phng ca kch thc gia cng vung gc vi nhau nn k = 0. bc tin tinh, do
cha d liu tnh ton nn ta c th xc nh k da vo bng 3.14 TL4, vi b mt
qua gia cng s b ta c: k = 140 (m).- Sai s do chn chun: bc tin th v
bn tinh, do chun nh v khng trng vi chun kch thc nn c sai s chun.
Sai s chun c ga tr bng dung sai ca kch thc tnh t chun o ti chun nh
v theo phng ca kch thc gia cng.
Vi phi c trong khun kim loi t cp chnh xc 12 n 14, kch thc tnh t
chun o n chun nh v l 95mm, ta c dung sai ca kch thc ny l 890 (m),
vy c = 870(m). bc tin tinh, do chun nh v trng vi chun o nn khng c
sai s chun, tc l c = 0.Vy sai s g t cc bc nh sau: Bc tin th: gd = 0
= 870(m);Bc tin bn tinh: gd = 0 = 870(m);Bc tin tinh: gd = k =
140(m).Nh vy lng d gia cng ti thiu cho cc bc khi gia cng b mt B nh
sau:Bc tin th: Zmin = 200+ 300+ 450+ 870 = 1820(m);Bc tin bn tinh:
Zmin = 50+ 18+ 870 = 938(m);Bc tin tinh: Zmin = 20+ 140 =
160(m).Theo phng php tnh lng d gia cng v cc kch thc gii hn theo cc
bc cng ngh cho mt ngoi, ta c bng kt qu sau:Trong :- Ct kch thc tnh
ton c xc nh nh sau:Ghi kch thc ca chi tit( kch thc nh nht theo bn
v) vo cui cng. Cc kch thc khc hnh thnh bng cch ly kch thc tnh ton
ca cc bc ngay sau n cng vi lng d tnh ton nh nht.- Dung sai ca cc
nguyn cng tm bng cch tra bng trong TL1.- Xc nh kch thc gii hn nh
nht bng cch lm trn kch thc tnh ton theo hng s c ngha ca dung sai
theo chiu tng.- Xc nh kch thc gii hn ln nht bng cch cng kch thc gii
hn nh nht vi dung sai tng ng. Bc cng nghCc thnh phn ca lng dLng d
tnh ton Zminkch thc tnh tonH,mmDung sai , mkch thc gii hn, mmLng d
gii hn, mm
RaTaaiHminHmaxZbminZbmax
Phi200300450109.258870109.26110.13
Tin th500188701820107.438500107.44107.9418202190
Bn tinh2000870938106.587106.5106.5879401353
Tng cng27603543
Kim tra kt qu tnh ton :Z0max- Z0min =3543 - 2760 = 783(m).ph- ct
= 870 - 87 = 783 (m).Ta thy kt qu tnh ton l chnh xc.2.1.7.2. Tra
lng d cho cc b mt cn li.Vi phng php c trong khun kim loi, phi c cp
chnh xc II, kch thc ln nht ca chi tit l 450, tra bng 3.95 TL1 ta c
lng d ca cc b mt khc ca chi tit nh sau:
B mtkch thcLng dDung sai
A1152,50,5
C3452x3+1
D1002,50,5
E4402x3+1
1222x3+0,5
2.1.8. Tnh ch ct cho mt nguyn cng. Tra ch ct cho cc nguyn cng cn
li.2.1.8.1. Tnh ch ct cho nguyn cng V.y l nguyn cng tin tinh 2 b mt
lp ghp B v C.a) Chiu su ct t = 0,6mm.b) Lng chy dao S = 0,23 mm/vng
tra bng 5.14 TL2.
c) Tc ct V: Trong :- CV v cc s m tra bng 5.17 TL2. CV =292; m
=0,2; x = 0,15; y = 0,2.- Chu k bn T khi gia cng mt dao theo TL2; T
= 50 (Pht).- H s iu chnh chung cho tc ct tnh n cc iu kin ct thc
t:kV = knv.kMV.kuv.+kMV : H s ph thuc vo vt liu gia cng, tra bng
5.1 TL2 ta c:
Kmv = +kuv: H s ph thuc vo vt liu dng c ct, tra bng 5.6 TL2 ta
c: Kuv = 1.+knv: h s ph thuc trng thi b mt ca phi, Tra bng 5.5 TL2
ta c: knv = 0,82. Vy kV = 1.0,82.1 = 0,82.
Tc ct: = 158,6 160 m/pht.Tc quay ca trc chnh:
N = (v/p).Theo dy tiu chun ca my chn N = 150 (v/p).d, Lc ct P.
Lc ct P c chia thnh 3 thnh phn theo to ca my, bao gm: lc ct theo
hng tip tuyn PZ; lc ct theo hng knh PY v lc ct theo hng trc PX c xc
nh theo cng thc sau: P X,Y,Z = 10.CP.tx.Sy.Vn.kp.Thnh phn PX: + Cp
v cc s m tra bng 5.23 TL2 ta c: Cp = 46; x = 1; y = 0,4; n = 0. +
KP: H s iu chnh ph thuc vo cc iu kin gia cng c th KP =
KMp.Kp.Kp.Kp.Krp, tra bng 5.9, 5.10 v 5.22 TL2 ta c: KMV = 1; Kp =
1; Kp = 1,4; Kp = 0,85; Krp = 1. KP = 1x1x1,4x0,85x1 = 1,19. vy Px
= 10x46x0,61x0,230,4x158,60x1,19 = 182,442(N).Thnh phn PY: + Cp v
cc s m tra bng 5.23 TL2 ta c: Cp = 54; x = 0,9; y = 0,75; n = 0. +
KP: H s iu chnh ph thuc vo cc iu kin gia cng c th KP =
KMp.Kp.Kp.Kp.Krp, tra bng 5.9, 5.10 v 5.22 TL2 ta c: KMV = 1; Kp =
1; Kp = 1,4; Kp = 1,25; Krp = 1. KP = 1x1x1,4x1,25x1 = 1,75. vy Px
= 10x54x0,60,9x0,230,75x158,60x1,75 = 198,18(N).Thnh phn PZ: + Cp v
cc s m tra bng 5.23 TL2 ta c: Cp = 92; x = 1; y = 0,75; n = 0. +
KP: H s iu chnh ph thuc vo cc iu kin gia cng c th KP =
KMp.Kp.Kp.Kp.Krp, tra bng 5.9, 5.10 v 5.22 TL2 ta c: KMV = 1; Kp =
1; Kp = 1,1; Kp = 1; Krp = 1. KP = 1x1x1,1x1x1 = 1,1. vy Px =
10x92x0,61x0,230,75x158,60x1,1 = 201,66(N).e) Cng sut ct.
Ne = kW.- Bng thng k ch ct:Tin tinh160 1500,60,2334,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
2.1.8. 2. Tnh ch ct cho cc nguyn cng cn li.a) Nguyn cng I: Bc 1:
Tin th l 122.- Chiu su ct: t =1,5 mm.- Lng chy dao tra bng 5.61-TL2
ta c: S = 0,4mm/vng( dao tin kiu 1 bng 4.14 TL1).- Tc ct tra bng
5.65 TL2: V = 87.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh
ph thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo
gc nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b
mt phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao,
k4 = 0,83. V = 87.0,72.0,83.1.1 = 52 m/pht. - Tc trc chnh: n =
1000V/.D = 1000.52/(3,14.122) = 135,74 vng/pht. Chn tc my: n = 150
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.122.150/1000 = 57,5
m/pht.- Lng chy dao pht: S = 0,4x150 = 60 mm/pht.Bc 2: Tin bn tinh
v vt mp l 122.- Chiu su ct: t =1mm.- Lng chy dao tra bng 5.62-TL2
ta c: S = 0,3mm/vng( dao tin kiu 1 bng 4.14 TL1).- Tc ct tra bng
5.65 TL2: V = 124.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh
ph thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo
gc nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b
mt phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao,
k4 = 0,83. V = 124.0,72.0,83.1.1 =74,1m/pht.- Tc trc chnh: n =
1000V/.D = 1000.74,1/(3,14.122) = 193,4 vng/pht.Chn tc my: n = 190
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.122.190/1000 = 72,78
m/pht.- Lng chy dao pht: S = 0,3.190 = 57 mm/pht.Bc 3: Tin th mt B
v C.- Chiu su ct: t =1.5mm.- Lng chy dao tra bng 5.62-TL2 ta c: S =
1 mm/vng( dao tin kiu 1 bng 4.14 TL1).- Tc ct tra bng 5.65 TL2: V =
87.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo chu
k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing chnh,
k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi, k3 = 1.
+ k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 = 0,83. V =
87.0,72.0,83.1.1 = 52 m/pht.- Tc trc chnh: n = 1000V/.D =
1000.52/(3,14.345) = 48 vng/pht.Chn tc my: n = 47,5 vng/pht. Tc ct
thc t: Vt = .D. n/1000 = 3,14.345.47,5/1000 = 51,45 m/pht.- Lng chy
dao pht: S = 1x47,5 = 47,5 mm/pht.Bc 4: Tin bn tinh mt B v C.- Chiu
su ct: t =1mm.- Lng chy dao tra bng 5.62-TL2 ta c: S = 0,7mm/vng(
dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng 5.65 TL2: V =
124.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo chu
k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing chnh,
k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi, k3 = 1.
+ k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 = 0,83. V =
124.0,72.0,83.1.1 =74,1m/pht.- Tc trc chnh: n = 1000V/.D =
1000.74,1/(3,14.345) = 68,4vng/pht. Chn tc my: n = 75 vng/pht. Tc
ct thc t: Vt = .D. n/1000 = 3,14.345.75/1000 = 81,25 m/pht. Lng chy
dao pht: S = 0,7x75 = 52,5 mm/pht.- Bng thng k ch ct:Tin bn
tinh74,17510,752,5
Tin th mt B, C5247,51,5147,5
Tin bn tinh74,119010,357
Tin th l 122521501,50,460
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
b) Nguyn cng II: Tin th v bn tinh mt D,C.Chn ch ct tng t nh khi
gia cng mt B v C.- Bng thng k ch ct:Tin bn tinh74,17510,752,5
Tin th mt D, E5247,51,5147,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
c) Nguyn cng III: Khoan, khot ming 6 l 12 pha mt D.Bc1: Khoan.Mi
khoan rut g thp gi 12.- Chiu su ct: t = 6 mm.- Lng chy dao tra bng
5.89-TL2 ta c: S = 0,45 mm/vng.- Tc ct tra bng 5.90 -TL2 ta c: Vb =
33 m/pht.- Tc tnh ton: Vt = Vb.k1.k2+ H s iu chnh k1 ph thuc chu k
bn ca mi khoan, k1=1,0.+ H s iu chnh k2 ph thuc chiu su khoan(bng
5.87-TL2), k2=1,0. Vt = 33.1.1 = 33 m/pht.- Tc quay ca trc chnh: N
= 1000Vt/.D = 1000.33/(3,14.12) = 875,8 vng/pht.Chn tc my: n = 850
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.12.850/1000 = 32,03
m/pht. Bc 2: Khot ming l.Dng mi khot ng knh 24 mm. Chiu su ct t = 6
mm. Lng chy dao S = 0,9 mm/vng. Tc ct tra theo bng 5.106 TL2, Vb =
20 m/ph. Tc quay ca trc chnh: n = 1000.20/(3,14.24) = 256,4
v/ph.Chn n = 250 v/ph.- Tc ct tnh ton li:
V= m/ph- Lng chy dao pht: Sp = 0,9.250 = 225 mm/ph.- Bng thng k
ch ct:Khot 2025060,9225
Khoan 3385060,45382,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
d) Nguyn cng IV: Khoan, khot ming 6 l 12 pha mt B.Chn ch ct nh
khi gia cng 6 l trn mt D.- Bng thng k ch ct:Khot 2025060,9225
Khoan 3385060,45382,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
e) Nguyn cng VI: Tin tinh mt D v E.Chn ch ct nh nguyn cng V.-
Bng thng k ch ct:Tin tinh160 1500,60,2334,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
2.1.9. Tnh thi gian gia cng c bn cho tt c cc nguyn cng. - Thi
gian nguyn cng c xc nh theo cng thc: Tct = To + Tp + Tpv + Ttn.
Trong : Tct : thi gian tng chic (thi gian nguyn cng ). To : thi
gian c bn(thi gian cn thit bin i trc tip hnh dng, kch thc, tnh cht
c l ca chi tit). Tp : thi gian ph(thi gian cn thit ngi cng nhn g,
tho chi tit, m my, mi dao, iu chnh my. . .), Tp = 0,1To. Tpv : thi
gian phc v ch lm vic gm: thi gian phc v k thut, mi dao, iu chnh my
. . ., Tpv = 0,11To. Ttn : thi gian ngh ngi t nhin ca cng nhn, Ttn
= 0,05To. Tct = To + 0,1To + 0,11To + 0,05To = 1,26To.- Thi gian c
bn c xc nh theo cng thc: To = (L1 + L2 + L)/(S.n).(pht) Trong : L:
Chiu di b mt gia cng (mm). L1: Chiu di n dao (mm). L2: Chiu di thot
dao (mm). S: Lng chy dao vng / hnh trnh kp. n: S vng quay hay hnh
trnh kp/pht. Nguyn cng I: Bc1: Tin th v bn tinh mt l 122.Tin th.Ch
ct ca bc cng ngh ny l: S = 0,4mm/vng. t = 1,5 mm. n = 150
vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L + L2).i/(S.n).Trong : S
ln gia cng i = 1. L = 43 mm . L1 = t.cotg + (0,5 n 2) mm. L1
=1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 = 2,5 mm. L2 = 3
mm.
T01 = pht.Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,3mm/vng. t
= 1 mm. n = 190 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 43 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (0,8+0,85) = 2,08 pht.Bc 2: Tin
th v bn tinh mt B, C. Tin th: Cc thng s ch ct: S = 1mm/vng. t = 1,5
mm. n = 47,5 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 52,5 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 =
2,5 mm. L2 = 3 mm.
T01 = pht.Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng. t
= 1 mm. n = 75 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 52,5 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (1,22+1,105) = 2,93 pht.Nguyn cng
II: Tin th v bn tinh mt D, E.Do kch thc mt D v E gn ging kch thc mt
B v C, nguyn cng ny li c cng ch gia cng nn ta c th ly thi gian gia
cng cho nguyn cng ny bng thi gian gia cng cho bc gia cng th v bn
tinh mt B v C, tc l:Tct = 1,26.To = 2,93 pht.Nguyn cng III: Khoan v
khot ming 6 l 12 mt D.Bc 1: khoan. S = 0,45 mm/vng. t = 6 mm. n =
850 vng/pht.Theo bng 5.6 TL[3] ta c: To = (L1 + L +
L2).i/(S.n)Trong : S ln gia cng i = 1. L = 15 mm . L1 = 0,5d.cotg +
(0,5 n 2). L2 = 3 mm.L1 = 0,5.12.cotg 59 +(0,5 n 2), chn L1 = 5 mm.
To = (5 + 15 + 3)/(0,45.850) = 0,06 pht. Tct = 1,26.To = 0,08 pht,
6 l nn Tct = 0,48 pht.Bc 2: khot tr mt u.. S = 0,9 mm/vng. t = 6
mm. n = 250 vng/pht.Theo bng 5.4 TL3 ta c:
Lcb = ph. Vi D= 24; d= 12; = 25o ta c: L1 = 0,5 n 2 mm chn L1 =
2 mm. L = 3 mm.
To = pht.6 l To =6x 0,022 = 0,133 pht. TCT = 1,26x0,133 =0,168
pht.Tng thi gian nguyn cng ny l: T = 0,48+ 0,168 = 0,648 pht.Nguyn
cng IV: khoan, khot tr 6 l 12 mt B.Thi gian nguyn cng ging nh khi
gia cng m D.Tng thi gian nguyn cng ny l: T = 0,48+ 0,168 = 0,648
pht.Nguyn cng V:Tin tinh mt B, C.Ch ct nguyn cng ny l: S = 0,23
mm/vng. t = 0,6 mm. n = 150 vng/pht.Gia cng mt B.Theo bng 5.7TL[3]
c: To = (L1 + L + L2).i/(S.n).Trong : S ln gia cng i = 1. L = 52,5
mm . L1 = t.cotg + (0,5 n 2) mm. L1 = 0,6.cotg60 + (0,5 n 2) = 0,8
n 2,3 mm. Chn L1 = 2 mm. L2 = 3 mm.
T01 = pht.Gia cng mt C. L = 6 mm. L1 = 2 mm. L2 = 3 mm.
T02 = pht.Tng thi gian nguyn cng ny l: T = 1,26x(1,666+ 0,32) =
2,502 pht.Nguyn cng VI: Tin tinh mt B v C. Thi gian nguyn cng nh
nguyn cng V.T = 2,502 pht.
2.2. Thit k cng ngh cho chi tit s 5.2.2.1. Bn v ch to chi
tit.
2.2.2.Phn tch chc nng lm vic ca chi tit.Chi tit c chc nng chnh l
trc chnh ca palng v kt ni vi cc phn khc ca v hp. Trn chi tit c 4 l
chnh dng lp bi trc v trn vnh c cc l nh v v l bt bu lng. Cc l chnh
phi c gia cng m bo vung gc gia ng tm l v b mt lp ghp theo yu cu. Cc
b mt lp ghp cng cn c gia cng chnh xc sao cho qu trnh lp ghp c thun
li v t cc yu cu k thut ra.2.2.3. Phn tch tnh cng ngh trong kt cu ca
chi tit.Da vo bn v chi tit ta thy nhn chung kt cu ca chi tit l ph
hp vi qu trnh to phi c, m bo chi tit cng vng trong qu trnh gia cng
cng nh qu trnh lm vic, cc mt cn gia cng c phn cch vi cc mt khng gia
cng. v tr ca cc b mt gia cng cng cho php a dng c vo khi gia cng mt
cch d dng. Kt cu ca chi tit cho php qu trnh g t d dng.2.2.4. Chn
phng php ch to phi. *Xc nh phng php ch to phiKt cu ca chi tit khng
phc tp nhng vt liu ca chi tit l gang xm 15x32 nn ta dng phng php c,
ng vi sn xut hng lot ln nn ta chn phng php c trong khun kim loi .
Sau khi c cn c nguyn cng lm sch v ct ba via .* Bn v lng phi ca chi
tit.
* Chn mt phn khun. 2.2.5. Trnh t cng ngh gia cng chi tit. NC1:
Tin th v bn tinh mt A, B, mt v vt mp l 100. NC2: Tin th v bn tinh
mtC v D, vt mp l 100. NC3: Khoan 6 l bt bu lng 12. NC4: Tin th v bn
tinh mt E, tin tinh mt B. NC5: Tin tinh mt D v E. NC6: Tin tinh mt
D v E.2.2.6. S nh v v kp cht, chn my v dao cho tng nguyn cng.Nguyn
cng 1: Tin th v bn tinh cc mt A, B, tin v vt mp l 100.- S nh v v kp
cht.Chi tit c nh v 5 bc t do bng cc chu kp ca my tin nh hnh v. Vic
kp cht c thc hin nh iu chnh cc chu kp to ra p lc ln mt bn ca chi
tit. S nh v v kp cht nh sau:
- Chn my v dao.+ Chn my.Vi kch thc ng knh ln nht ca chi tit phi
gia cng l 440 mm, ng thi ph hp vi iu kin sn xut ca nc ta hin nay,
chn my gia cng l my tin vn nng 1K625. Cc thng s k thut ch yu ca my
nh sau: ng knh gia cng ln nht : 500 mm; Khong cch hai u tm:
1000-1400-2000 mm; ng knh ln nht ca chi tit gia cng c trn bn dao:
260 mm; Chiu di ln nht tin c trn hai u tm: 930-1330-1930; ng knh ln
nht ca vt lun qua trc chnh: 50mm; ng knh l trc chnh: 52 mm; cn trc
chnh, mooc : N06; S cp tc : 23; Gii hn vng quay: 12,52000 vng/pht;
S cp tc chy dao : 12 cp; Gii hn chy dao : dc 0,074,16 mm/v; ngang
0,0352,08 mm/v; Cng sut ng c: 10 kW; Kch thc my 2812x1216x1349 mm;
phc tp sa cha R: 29.+ Chn dao. .Tin mt u: dng dao tin ngoi thn cong
gn mnh hp kim cng BK8 vi cc kch thc H=25, B =16( Bng 4.4-TL1).. Tin
l: dng dao tin l gn mnh hp kim cng BK8 vi cc kch thc h=20; b =20(
Bng 4.13-TL1).Nguyn cng 2: Tin th v bn tinh mt C, D, vt mp l 100. -
S nh v v kp cht.Chi tit c nh v 5 bc t do bng cc chu kp ca my tin nh
hnh v. Vic kp cht c thc hin nh iu chnh cc chu kp to ra p lc ln mt
bn ca chi tit. S nh v v kp cht nh sau:
- Chn my v dao.Vic chn my v dao nh nguyn cng trn.Ngun cng 3:
Khoan 6 l bt bu lng 12 .- S nh v v kp cht.Trong nguyn cng ny ta s
dng phin dn c lp cc bc dn, phin dn c nh v trc tip vo chi tit theo 5
bc t do thng qua cc cht t t vo mt trn A gia cng ca chi tit khng ch
3 bc v cht tr nh v vo mt l chnh khng ch 2 bc. C cm chi tit c lp
phin dn v bc dn c nh v vo thn g thng qua phin t t vo mt C khng ch 3
bc t do. Vic kp cht chi tit, phin dn c thc hin nh bu lng ai c bt
cht vo thn g. S nh v v kp cht nh sau:
- Chn my v dng c ct..Chn my:Vi kch thc chi tit nh vy ta c th gia
cng trn my khoan cn 2H52. Cc thng s c bn ca my khoan cn 2H53 nh
sau: ng knh gia cng ln nht : 35 mm; Khong cch t tm trc chnh ti trc
my: 3201250 mm; Khong cch t trc chnh ti bn my: 4001400 mm; cn trc
chnh : moc N04; S cp tc : 12; Gii hn vng quay: 252500 vng/pht; S cp
tc cp tc chy dao : 12 cp; Gii hn chy dao : 0,0561,22 mm/vng; Dch
chuyn ngang ln nht ca u khoan: 900mm; Gc quay ln nht ca cn xung
quanh trc thng ng: 3600; Dch chuyn thng ng ln nht ca cn: 700 mm;
Dch chuyn thng ng ln nht ca trc chnh: 300mm; Cng sut ng c chnh: 2,8
kW; Kch thc my 2240x870x3035 mm; phc tp sa cha R: 29..Chn dao: Chn
mi khoan rut g tra bng 4.41 TL1 bng thp gi P18 ui tr loi ngn vi ng
knh d = 12mm, chiu di L = 102mm , chiu di phn lm vic l = 51mm.Nguyn
cng 4: Tin th v bn tinh mt ngoi E, tin tinh mt B.- S nh v v kp cht.
nguyn cng ny, sau khi c cc b mt qua gia cng, ta s dng b mt lp ghp D
v mt l chnh 100 lm cc mt nh v. Phin t t vo mt D khng ch 3 bc t do,
cht tr ngn nh v vo mt l chnh khng ch 2 bc t do. Vic kp cht chi tit
c thc hin bng bu lng lun qua l chnh ca chi tit. S nh v v kp cht c
thc hin nh sau:
- Chn my v dao.Chn my v dao nh nguyn cng 1 v 2.Nguyn cng 5: Tin
tinh 2 b mt lp ghp cn li D v E.- S nh v v kp cht.Chi tit c nh v 5
bc t do: phin t t vo mt B khng ch 3 bc t do, cht tr ngn nh v vo mt
l 100 khng ch 2 bc t do. Vic kp cht chi tit vo thn g cng c thc hin
bng bu lng lun qua l chnh ca chi tit. S nh v v kp cht nh sau:
- Chn my v dao.Chn my v dao nh nguyn cng trn.2.2.7. Tra lng d
cho cc b mt ca chi tit.Da vo phng php ch to phi, vt liu ca chi tit
v cc kch thc ca chi tit, theo TL1 ta tra c lng d cn thit cho cc b
mt ca chi tit nh sau:B mtkch thcLng dDung sai
A,C432x2,50,5
B,D162x2,5+0,3
1001002x3+0,5
50502x2,5+0,5
60602x2,5+0,5
70702x2,5+0,5
2.2.8. Tra ch ct cho cc nguyn cng.a) Nguyn cng I: Bc 1: Tin th l
100.- Chiu su ct: t =1,5 mm.- Lng chy dao tra bng 5.61-TL2 ta c: S
= 0,4 mm/vng( dao tin kiu 1 bng 4.14 TL1).- Tc ct tra bng 5.65 TL2:
V = 87.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo
chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing
chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi,
k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 =
0,83. V = 87.0,72.0,83.1.1 = 52 m/pht.- Tc trc chnh: n = 1000V/.D =
1000.52/(3,14.100) = 165,6 vng/pht.Chn tc my: n = 190 vng/pht. Tc
ct thc t: Vt = .D. n/1000 = 3,14.100.190/1000 = 59,66m/pht.- Lng
chy dao pht: S = 0,4x190 = 76 mm/pht.Bc 2: Tin bn tinh v vt mp l
100.- Chiu su ct: t =1mm.- Lng chy dao tra bng 5.62-TL2 ta c: S =
0,3 mm/vng( dao tin kiu 1 bng 4.14 TL1).- Tc ct tra bng 5.65 TL2: V
= 124.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo
chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing
chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi,
k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 =
0,83. V = 124.0,72.0,83.1.1 =74,1m/pht.- Tc trc chnh: n = 1000V/.D
= 1000.74,1/(3,14.100) = 235,98 vng/pht.Chn tc my: n = 250 vng/pht.
Tc ct thc t: Vt = .D. n/1000 = 3,14.100.250/1000 = 78,5 m/pht.- Lng
chy dao pht: S = 0,3x250 = 75 mm/pht.Bc 3: Tin th mt B v C.- Chiu
su ct: t =1,5mm.- Lng chy dao tra bng 5.62-TL2 ta c: S = 1 mm/vng(
dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng 5.65 TL2: V =
87.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo chu
k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing chnh,
k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi, k3 = 1.
+ k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 = 0,83. V =
87.0,72.0,83.1.1 = 52 m/pht. - Tc trc chnh: n = 1000V/.D =
1000.52/(3,14.440) = 37,6 vng/pht. Chn tc my: n = 37,5 vng/pht. Tc
ct thc t: Vt = .D. n/1000 = 3,14.440.37,5/1000 = 51,81 m/pht.- Lng
chy dao pht: S = 1x37,5 = 37,5 mm/pht.Bc 4: Tin bn tinh mt B v C. -
Chiu su ct: t =1mm. - Lng chy dao tra bng 5.62-TL2 ta c: S =
0,7mm/vng( dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng 5.65 TL2: V
= 124.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo
chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing
chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi,
k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 =
0,83. V = 124.0,72.0,83.1.1 =74,1m/pht. - Tc trc chnh: n = 1000V/.D
= 1000.74,1/(3,14.440) = 53,6 vng/pht. Chn tc my: n = 60 vng/pht.
Tc ct thc t: Vt = .D. n/1000 = 3,14.440.60/1000 = 82,9 m/pht.- Lng
chy dao pht: S = 0,7x60 = 42 mm/pht.- Bng thng k ch ct:Tin bn
tinh74,16010,742
Tin th mt B, C5237,51,5137,5
Tin bn tinh74,125010,7175
Tin th l 122521901,51190
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
b) Nguyn cng II: Tin th v bn tinh mt D,C.Chn ch ct tng t nh khi
gia cng mt A v B.- Bng thng k ch ct:Tin bn tinh74,16010,742
Tin th mt D, C5237,51,5137,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
c) Nguyn cng III: Khoan 6 l 12.Mi khoan rut g thp gi 12.- Chiu
su ct: t = 6 mm.- Lng chy dao tra bng 5.89-TL2 ta c: S = 0,45
mm/vng.- Tc ct tra bng 5.90 -TL2 ta c: Vb = 33 m/pht.- Tc tnh ton:
Vt = Vb.k1.k2+ H s iu chnh k1 ph thuc chu k bn ca mi khoan,
k1=1,0.+ H s iu chnh k2 ph thuc chiu su khoan(bng 5.87-TL2),
k2=1,0. Vt = 33.1.1 = 33 m/pht. - Tc quay ca trc chnh: N =
1000Vt/.D = 1000.33/(3,14.12) = 875,8 vng/pht. Chn tc my: n = 850
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.12.850/1000 = 32,03
m/pht. Lng chy dao pht: S = 0,45x850 = 382,5 mm/pht.- Bng thng k ch
ct:Khoan 32,0385060,45382,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
d) Nguyn cng IV:Tin th mt ngoi E, tin tinh mt bn B.Bc 1: Tin th
mt E. - Chiu su ct: t =1.5mm. - Lng chy dao tra bng 5.62-TL2 ta c:
S = 1 mm/vng( dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng 5.65
TL2: V = 87.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph
thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc
nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt
phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4
= 0,83. V = 87.0,72.0,83.1.1 = 52 m/pht.- Tc trc chnh: n = 1000V/.D
= 1000.52/(3,14.440) = 37,6 vng/pht. Chn tc my: n = 37,5 vng/pht.
Tc ct thc t: Vt = .D. n/1000 = 3,14.440.37,5/1000 = 51,81 m/pht.-
Lng chy dao pht: S = 1x37,5 = 37,5 mm/pht.Bc 2: Tin tinh mt B:-
Chiu su ct: t = 0,5mm. - Lng chy dao tra bng 5.62-TL2 ta c: S =
0.23 mm/vng( dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng 5.65 TL2:
V = 250.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph thuc vo
chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc nghing
chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt phi,
k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4 =
0,83. V = 250.0,72.0,83.1.1 = 149,4 m/pht. - Tc trc chnh: n =
1000V/.D = 1000.149,4/(3,14.440) = 108,13 vng/pht. Chn tc my: n =
118 vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.440.118/1000 = 163
m/pht.- Lng chy dao pht: S = 0,23x118= 27,14 mm/pht.- Bng thng k ch
ct:Tin tinh mt B1631180,50,2327,14
Tin th mt E5237,51,5137,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
e) Nguyn cng V: Tin tinh mt ngoi E v mt bn cn li D.Chn ch ct tng
t khi gia cng mt B.- Bng thng k ch ct:Tin tinh mt
E,D1631180,50,2327,14
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
2.2.9. Tnh thi gian gia cng c bn cho tng nguyn cng.Nguyn cng I:
Bc1: Tin th v bn tinh mt l 100.Tin th.Ch ct ca bc cng ngh ny l: S =
0,4 mm/vng. t = 1,5 mm. n = 190 vng/pht.Theo bng 5.7TL[3] c: To =
(L1 + L + L2).i/(S.n).Trong : S ln gia cng i = 1. L = 34 mm . L1 =
t.cotg + (0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm.
Chn L1 = 2,5 mm. L2 = 3 mm.
T01 = pht.Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,3 mm/vng.
t = 1 mm. n = 250 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 34 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (0,52+0,56) = 1,36 pht.Bc 2: Tin
th v bn tinh mt A,B. - Mt A:*Tin th:Cc thng s ch ct: S = 1mm/vng. t
= 1,5 mm. n = 37,5 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 196 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 =
2,5 mm. L2 = 3 mm.
T01 = pht.*Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng.
t = 1 mm. n = 60 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 196 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (5,37+4,8) = 12,8 pht.- Mt B:*Tin
th:Cc thng s ch ct: S = 1mm/vng. t = 1,5 mm. n = 37,5 vng/pht.Theo
bng 5.7TL[3] c: To = (L1 + L + L2).i/(S.n).Trong : S ln gia cng i =
1. L = 24 mm . L1 = t.cotg + (0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n
2) =1,4 n 2,8 mm. Chn L1 = 2,5 mm. L2 = 3 mm.
T01 = pht.*Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng.
t = 1 mm. n = 60 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 24 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (0,78+0,7) = 1,865 pht.Vy tng thi
gian cho nguyn cng ny l: T = 12,8 +1,865 = 14,665 pht.2. Nguyn cng
II: Tin th v bn tinh mt C, D.Do kch thc mt C v D gn ging kch thc mt
A v B, nguyn cng ny li c cng ch gia cng nn ta c th ly thi gian gia
cng cho nguyn cng ny bng thi gian gia cng cho bc gia cng th v bn
tinh mt A vB, tc l:Tct = 12,665 pht.Nguyn cng III: Khoan 6 l 12.Ch
ct nguyn cng ny l: S = 0,45 mm/vng. t = 6 mm. n = 850 vng/pht.Theo
bng 5.6 TL[3] ta c: To = (L1 + L + L2).i/(S.n)Trong : S ln gia cng
i = 1. L = 16 mm . L1 = 0,5d.cotg + (0,5 n 2). L2 = 3 mm.L1 =
0,5.12.cotg 59 +(0,5 n 2), chn L1 = 5 mm. To = (5 + 16 +
3)/(0,45.850) = 0,06 pht. Tct = 1,26.To = 0,08 pht, 6 l nn Tct =
0,48 pht.Nguyn cng IV: Tin th v bn tinh mt E, tin tinh mt B.Bc 1:
Tin th v bn tinh mt E.*Tin th:Cc thng s ch ct: S = 1mm/vng. t = 1,5
mm. n = 37,5 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 24 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 =
2,5 mm. L2 = 3 mm.
T01 = pht.*Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng.
t = 1 mm. n = 60 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 24 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (0,78+0,7) = 1,865 pht.Bc 2: Tin
tinh mt B.Ch ct nguyn cng ny l: S = 0,23 mm/vng. t = 0,5 mm. n =
118 vng/pht.Gia cng mt B.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 26 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 = 0,6.cotg60 + (0,5 n 2) = 0,8 n 2,3 mm. Chn L1 =
2 mm. L2 = 3 mm.
T01 = pht.Tct = 1,26.To = 1,26x1,142 = 1,44 pht.Tng thi gian
nguyn cng ny l: T = 1,865+ 1,44 = 3,305 pht.Nguyn cng V: Tin tinh
mt E v D.Ch ct nguyn cng ny l: S = 0,23 mm/vng. t = 0,5 mm. n = 118
vng/pht.Gia cng mt E.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 16 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 = 0,6.cotg60 + (0,5 n 2) = 0,8 n 2,3 mm. Chn L1 =
2 mm. L2 = 3 mm.
T01 = pht.Gia cng mt D. L = 26 mm. L1 = 2 mm. L2 = 3 mm.
T02 = pht.Tng thi gian nguyn cng ny l: T = 1,26x(0,774+ 1,142) =
2,41 pht.
2.3. Thit k cng ngh cho chi tit s 6.2.3.1. Bn v ch to chi
tit.
2.3.2.Phn tch chc nng lm vic ca chi tit.Chi tit c chc nng chnh l
trc chnh ca palng v kt ni vi cc phn khc ca v hp. Trn chi tit c 4 l
chnh dng lp bi trc v trn vnh c cc l nh v v l bt bu lng. Cc l chnh
phi c gia cng m bo vung gc gia ng tm l v b mt lp ghp theo yu cu. Cc
b mt lp ghp cng cn c gia cng chnh xc sao cho qu trnh lp ghp c thun
li v t cc yu cu k thut ra.2.3.3. Phn tch tnh cng ngh trong kt cu ca
chi tit.Da vo bn v chi tit ta thy nhn chung kt cu ca chi tit l ph
hp vi qu trnh to phi c, m bo chi tit cng vng trong qu trnh gia cng
cng nh qu trnh lm vic, cc mt cn gia cng c phn cch vi cc mt khng gia
cng. v tr ca cc b mt gia cng cng cho php a dng c vo khi gia cng mt
cch d dng. Kt cu ca chi tit cho php qu trnh g t d dng.2.3.4. Chn
phng php ch to phi. *Xc nh phng php ch to phiKt cu ca chi tit khng
phc tp nhng vt liu ca chi tit l gang xm 15x32 nn ta dng phng php c,
ng vi sn xut hng lot ln nn ta chn phng php c trong khun kim loi .
Sau khi c cn c nguyn cng lm sch v ct ba via .* Bn v lng phi ca chi
tit.
* Chn mt phn khun. 2.3.5. Trnh t cng ngh gia cng chi tit. NC1:
Tin th v bn tinh mt A, B, mt v vt mp l 72. NC2: Tin th v bn tinh
mtC v D. NC3: Khoan, doa v taro ren 6 l M10x1,5. NC4: Phay tinh mt
A,B. NC5: Tin tinh mt C v D. NC6: Khoan v kho mt E. NC7: Khoan v
kho mt F. NC8: Taro ren M15x1.5 mt E. NC9: Taro ren M15x1.5 mt
F.2.3.6. S nh v v kp cht, chn my v dao cho tng nguyn cng.Nguyn cng
1: Tin th v bn tinh cc mt A, B, tin v vt mp l 72.- S nh v v kp
cht.Chi tit c nh v 5 bc t do bng cc chu kp ca my tin nh hnh v. Vic
kp cht c thc hin nh iu chnh cc chu kp to ra p lc ln mt bn ca chi
tit. S nh v v kp cht nh sau:
- Chn my v dao.+ Chn my.Vi kch thc ng knh ln nht ca chi tit phi
gia cng l 450 mm, ng thi ph hp vi iu kin sn xut ca nc ta hin nay,
chn my gia cng l my tin vn nng 1K625. Cc thng s k thut ch yu ca my
nh sau: ng knh gia cng ln nht : 500 mm; Khong cch hai u tm:
1000-1400-2000 mm; ng knh ln nht ca chi tit gia cng c trn bn dao:
260 mm; Chiu di ln nht tin c trn hai u tm: 930-1330-1930; ng knh ln
nht ca vt lun qua trc chnh: 50mm; ng knh l trc chnh: 52 mm; cn trc
chnh, mooc : N06; S cp tc : 23; Gii hn vng quay: 12,52000 vng/pht;
S cp tc chy dao : 12 cp; Gii hn chy dao : dc 0,074,16 mm/v; ngang
0,0352,08 mm/v; Cng sut ng c: 10 kW; Kch thc my 2812x1216x1349 mm;
phc tp sa cha R: 29.+ Chn dao. .Tin mt u: dng dao tin ngoi thn cong
gn mnh hp kim cng BK8 vi cc kch thc H=25, B =16( Bng 4.4-TL1).. Tin
l: dng dao tin l gn mnh hp kim cng BK8 vi cc kch thc h=20; b =20(
Bng 4.13-TL1)Nguyn cng 2: Tin th v bn tinh mt C, D. - S nh v v kp
cht.Chi tit c nh v 5 bc t do nh phin t t vo mt A v cht tr ngn nh v
vo mt l 72 nh hnh v. Vic kp cht c thc hin bng bu lng- ai c thng qua
2 l chnh nh hnh v. S nh v v kp cht nh sau:
- Chn my v dao.Vic chn my v dao nh nguyn cng trn.Ngun cng 3:
Khoan, doa, taro ren 6 l ren M10x1.5 .- S nh v v kp cht.Trong nguyn
cng ny ta s dng phin dn c lp cc bc dn, phin dn c nh v trc tip vo
chi tit theo 5 bc t do thng qua cc cht t t vo mt trn C gia cng ca
chi tit khng ch 3 bc v cht tr nh v vo mt l chnh khng ch 2 bc. C cm
chi tit c lp phin dn v bc dn c nh v vo thn g thng qua phin t t vo
mt A khng ch 3 bc t do. Vic kp cht chi tit, phin dn c thc hin nh bu
lng ai c bt cht vo thn g. S nh v v kp cht nh sau:
- Chn my v dao..Chn my:Vi kch thc chi tit nh vy ta c th gia cng
trn my khoan cn 2H53. Cc thng s c bn ca my khoan cn 2H53 nh sau: ng
knh gia cng ln nht : 35 mm; Khong cch t tm trc chnh ti trc my:
3201250 mm; Khong cch t trc chnh ti bn my: 4001400 mm; cn trc chnh
: moc N04; S cp tc : 12; Gii hn vng quay: 252500 vng/pht; S cp tc
cp tc chy dao : 12 cp; Gii hn chy dao : 0,0561,22 mm/vng; Dch chuyn
ngang ln nht ca u khoan: 900mm; Gc quay ln nht ca cn xung quanh trc
thng ng: 3600; Dch chuyn thng ng ln nht ca cn: 700 mm; Dch chuyn
thng ng ln nht ca trc chnh: 300mm; Cng sut ng c chnh: 2,8 kW; Kch
thc my 2240x870x3035 mm; phc tp sa cha R: 29..Chn dao: Chn dng c
gia cng l mi khoan doa t hp dn hng pha sau tra bng 4.54 TL1 bng thp
gi P18, dng c taro ren bng thp gi P18.Nguyn cng 4: Phay tinh mt lp
ghp A, B.- S nh v v kp cht:Chi tit c nh v 6 bc t do: phin t t vo mt
C khng ch 3 bc t do; hai khi V t vo mt tr ngoi khng ch 3 bc t do cn
li. Vic kp cht c thc hin nh vic quay tay quay thng qua khi Vdi ng.
S nh v v kp cht chi tit nh sau:
- Chn my v dao.. Chn my:Chn my phay ng vn nng 6H13:Cc thng s k
thut ca my nh sau: kch thc ca my: di x rng x cao = 2370 x 3140 x
2245; S cp tc trc chnh: 18; Phm vi tc trc chnh: 63 1500; Cng sut ng
c chnh: 10 Kw; Cng sut ng c chy dao: 2,8 kw; kch thc b mt lm vic ca
bn my: rng x di = 400 x 1600; S rnh ch T: 3; Chiu rng rnh ch T : 18
mm; dch chuyn nhanh ca bn my: dc, ngang; thng; ng = 2300; 2300;770
mm; s cp bc tin ca bn my: 18; Bc tin bn my: + dc: 23,5 n 1180
mm/ph; + ngang: 8 n 390 mm/ph.. Chn dao:Chn dao phay mt u thp gi
theo bng 4.92 TL1 vi cc thng s k thut ch yu sau: D(js) = 100 mm; d
= 32mm; L = 50mm; s rng Z = 18.Nguyn cng 5: Tin tinh 2 b mt lp ghp
C v D.- S nh v v kp cht.Chi tit c nh v 5 bc t do: phin t t vo mt A
khng ch 3 bc t do, cht tr ngn nh v vo mt l 72 khng ch 2 bc t do.
Vic kp cht chi tit vo thn g cng c thc hin bng 2 bu lng lun qua l
chnh ca chi tit. S nh v v kp cht nh sau:
- Chn my v dao.Vic chn my v dao nh nguyn cng 2.Nguyn cng 6:
Khoan, kho mt E.- S nh v v kp cht:Chi tit c nh v 6 bc t do: phin t
t vo mt B khng ch 3 bc t do; cht tr ngn nh v vo mt l 72 khng ch 2
bc t do; vic chng xoay ca chi tit c thc hin nh cht t t vo mt ngoi
ca gn tr lc. S nh v v kp cht nh sau:
- Chn my v dao:. Chn my:Nguyn cng c thc hin trn my phay ngang
6H82, cc thng s k thut chnh ca my nh sau: kch thc ca my: di x rng x
cao = 2440 x 2440 x 2350; S cp tc trc chnh: 18; Phm vi tc trc chnh:
30 1500; Cng sut ng c chnh: 7 KW; Cng sut ng c chy dao: 1,7 kw; kch
thc b mt lm vic ca bn my: rng x di = 320 x 250; S rnh ch T: 3; Chiu
rng rnh ch T : 18 mm; dch chuyn nhanh ca bn my: dc, ngang; thng; ng
= 2300; 2300;770 mm; s cp bc tin ca bn my: 18; Bc tin bn my: + dc:
23,5 n 1180 mm/ph; + ngang: 23,5 n 1180 mm/ph.. Chn dao: Chn dng c
gia cng t hp khoan v kho mt u.Nguyn cng 7: Khoan v kho mt F.S nh v,
g t v kp cht ging nh nguyn cng 6.Vic chn my v dao cng ging nh nguyn
cng 6.Nguyn cng 8: Taro ren M15x1.5 pha mt E.- S nh v v kp
cht.Nguyn cng ny thc hin trn my khoan cn, do yu cu v tr mt gia cng
v my l c nh nn chi tit c nh v c 6 bc t do: phin t t vo mt B khng ch
3 bc t do; cht tr ngn nh v vo mt l 72 khng ch 2 bc t do; vic chng
xoay ca chi tit c thc hin bng cht t t vo mt bn ca gn tr lc. S nh v
v kp cht nh sau:
- Chn my v dao.. Chn my:Chn my khoan cn 2H53 nh s dng cc
nguyncng trc.. Chn dao: dng c ta r ren c ng knh danh ngha 15mm v bc
ren 1,5 mm.Nguyn cng 9: Taro ren M15x1.5 pha mt F.- S nhv v kp cht.
Vic nh v v kp cht chi tit c thc hin ging nh nguyn cng 8, ch khc l
chi tit c xoay i 1800 hng mt F ln trc dng c. S nh v v kp cht nh
sau:
- Chn my v dng c.Vic chn my v dng c ct ging nh nguyn cng
8.2.3.7. Tra lng d cho cc b mt ca chi tit.Da vo phng php ch to phi,
vt liu ca chi tit v cc kch thc ca chi tit, theo TL1 ta tra c lng d
cn thit cho cc b mt ca chi tit nh sau:B mtkch thcLng dDung sai
A,B,C1652x3,50,5
D4402x3,5+0,3
E,F3642x3,5+0,5
90902x3+0,5
50502x2,5+0,5
60602x2,5+0,5
70722x2,5+0,5
2.3.8. Tra ch ct cho tt tng nguyn cng.a) Nguyn cng I: Bc 1: Tin
th l 72. - Chiu su ct: t =1,5 mm. - Lng chy dao tra bng 5.61-TL2 ta
c: S = 0,4mm/vng( dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng 5.65
TL2: V = 87.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh ph
thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo gc
nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b mt
phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao, k4
= 0,83. V = 87.0,72.0,83.1.1 = 52 m/pht. - Tc trc chnh: n =
1000V/.D = 1000.52/(3,14.72) = 230 vng/pht. Chn tc my: n = 235
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.72.235/1000 =
53,13/pht.- Lng chy dao pht: S = 0,4x235 = 94 mm/pht.Bc 2: Tin bn
tinh v vt mp l 72. - Chiu su ct: t = 1mm. - Lng chy dao tra bng
5.62-TL2 ta c: S = 0,3mm/vng( dao tin kiu 1 bng 4.14 TL1). - Tc ct
tra bng 5.65 TL2: V = 124.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s
hiu chnh ph thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph
thuc vo gc nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo
trng thi b mt phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim
cng ca dao, k4 = 0,83. V = 124.0,72.0,83.1.1 =74,1m/pht. - Tc trc
chnh: n = 1000V/.D = 1000.74,1/(3,14.72) = 327,76 vng/pht. Chn tc
my: n = 300 vng/pht. Tc ct thc t: Vt = .D. n/1000 =
3,14.72.300/1000 = 67,8 m/pht.- Lng chy dao pht: S = 0,3x300 = 90
mm/pht.Bc 3: Tin th mt A v B.- Chiu su ct: t =1.5mm.- Lng chy dao
tra bng 5.62-TL2 ta c: S = 1 mm/vng( dao tin kiu 1 bng 4.14 TL1). -
Tc ct tra bng 5.65 TL2: V = 87.K1.K2.K3.K4 (mm/pht). Trong : + k1:
h s hiu chnh ph thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh
ph thuc vo gc nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo
trng thi b mt phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim
cng ca dao, k4 = 0,83. V = 87.0,72.0,83.1.1 = 52 m/pht.- Tc trc
chnh: n = 1000V/.D = 1000.52/(3,14.450) = 36,8 vng/pht.Chn tc my: n
= 37,5 vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.450.37,5/1000 =
53 m/pht.- Lng chy dao pht: S = 1x37,5= 37,5 mm/pht.Bc 4: Tin bn
tinh mt A v B. - Chiu su ct: t =1mm. - Lng chy dao tra bng 5.62-TL2
ta c: S = 0,7mm/vng( dao tin kiu 1 bng 4.14 TL1). - Tc ct tra bng
5.65 TL2: V = 124.K1.K2.K3.K4 (mm/pht). Trong : + k1: h s hiu chnh
ph thuc vo chu k bn ca dao, k1 = 1. + k2: h s hiu chnh ph thuc vo
gc nghing chnh, k2 = 0,72. + k3: h s hiu chnh ph thuc vo trng thi b
mt phi, k3 = 1. + k4: h s hiu chnh ph thuc vo mc hp kim cng ca dao,
k4 = 0,83. V = 124.0,72.0,83.1.1 =74,1m/pht. - Tc trc chnh: n =
1000V/.D = 1000.74,1/(3,14.450) = 52,44 vng/pht. Chn tc my: n = 60
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.450.60/1000 =
84,7m/pht.- Lng chy dao pht: S = 0,7x60 = 42 mm/pht.- Bng thng k ch
ct:Tin bn tinh84,76010,742
Tin th mt A, B5337,51,5137,5
Tin bn tinh67,830010,390
Tin th l 7253,132351,50,494
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
b) Nguyn cng II: Tin th v bn tinh mt D, C.Chn ch ct tng t nh khi
gia cng mt A v B.- Bng thng k ch ct:Tin bn tinh83,46010,742
Tin th mt D, C5337,51,5137,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
c) Nguyn cng III: Khoan, doa, taro ren 6 l M10x1,5.Bc 1: Khoan v
doa.V nguyn cng ny ta dng dng c t hp khoan v doa ng thi, do bc
khoan c lc ct ln hn v chnh xc l gia cng khng i hi cao nn ta tnh ch
ct nh khi khoan.- Chiu su ct: t = 5 mm.- Lng chy dao tra bng
5.89-TL2 ta c: S = 0,45 mm/vng.- Tc ct tra bng 5.90 -TL2 ta c: Vb =
33 m/pht.- Tc tnh ton: Vt = Vb.k1.k2+ H s iu chnh k1 ph thuc chu k
bn ca mi khoan, k1=1,0.+ H s iu chnh k2 ph thuc chiu su khoan(bng
5.87-TL2), k2=1,0. Vt = 33.1.1 = 33 m/pht. - Tc quay ca trc chnh: N
= 1000Vt/.D = 1000.33/(3,14.10) = 1051 vng/pht. Chn tc my: n = 1180
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.10.1180/1000 = 37
m/pht. Bc2: Taro ren.Vi kch thc danh ngha ca ren M10, bc ren 1.5,
ren ct yu cu cp chnh xc thng thng, ren kp cht v vt liu gia cng l
gang xm, tra bng 5.188 TL2 ta c vn tc ct ren: V = 12x1,1 = 13,2
m/pht. - Bng thng k ch ct:Taro ren13,242011,5630
Khoan doa37118050,45531
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
d) Nguyn cng IV: Phay tinh mt lp ghp A,B.- Chiu su ct: t = 0,5
mm.- Lng chy dao rng: Sz = 0,1 mm/rng. Lng chy dao vng: Sv = 180,1
= 1,8 mm/vng.-Tc ct tra bng 5.127 TL2 ta c: Vb = 228.1.1,13.1,1.1
=283,4 283 mm/pht.-Tc tnh ton: Vt = Vb.kmv.knv.kuv Trong : kmv: H s
ph thuc vo cht lng ca vt liu gia cng, Tra bng 5.1[2] c: k1 = 1.
knv: H s ph thuc vo tnh trng ca b mt phi, Tra bng 5.5[2] c k2 =
0,82. kuv: H s ph thuc vo cht lng ca vt liu dng c ct, Tra bng
5.6[2] c k3 = 1. Vt = 283,4.0,82.1,0.1,0 = 232,4 232 m/pht.- Tc trc
chnh: n = 1000Vt/.D = 1000.232/3,14.100 = 740 vng/pht.Chn tc my:
nm= 750 vng/pht. Tc ct thc t: Vt = .D. nm/1000 = 3,14.100.750/1000
= 235,5 m/pht.- Lng chy dao pht: Sp = 750.1,8 = 1350 mm/pht. - Bng
thng k ch ct:Phay tinh 2327500,51,81350
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
e) Nguyn cng V: Tin tinh 2 mt C, D. - Chiu su ct: t = 0,5mm. -
Lng chy dao tra bng 5.62-TL2 ta c: S = 0.23 mm/vng( dao tin kiu 1
bng 4.14 TL1). - Tc ct tra bng 5.65 TL2: V = 250.K1.K2.K3.K4
(mm/pht). Trong : + k1: h s hiu chnh ph thuc vo chu k bn ca dao, k1
= 1. + k2: h s hiu chnh ph thuc vo gc nghing chnh, k2 = 0,72. + k3:
h s hiu chnh ph thuc vo trng thi b mt phi, k3 = 1. + k4: h s hiu
chnh ph thuc vo mc hp kim cng ca dao, k4 = 0,83. V =
250.0,72.0,83.1.1 = 149,4 m/pht.- Tc trc chnh: n = 1000V/.D =
1000.149,4/(3,14.440) = 108,13 vng/pht. Chn tc my: n = 118 vng/pht.
Tc ct thc t: Vt = .D. n/1000 = 3,14.440.118/1000 = 163 m/pht.- Lng
chy dao pht: S = 0,23x118= 27,14 mm/pht.- Bng thng k ch ct:Tin tinh
mt C, D1631180,50,2327,14
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
f) Nguyn cng VI: Khoan l 15 v kho mt E. nguyn cng ny ta dng dng
c t hp khoan v kho mt, do chiu di khoan ln hn nhiu so vi chiu di
kho mt nn ta c th tnh ch ct cho bc khoan v dng lm ch ct chung cho c
nguyn cng.- Chiu su ct: t = 7,5 mm.- Lng chy dao tra bng 5.89-TL2
ta c: S = 0,45 mm/vng.- Tc ct tra bng 5.90 -TL2 ta c: Vb = 33
m/pht.- Tc tnh ton: Vt = Vb.k1.k2+ H s iu chnh k1 ph thuc chu k bn
ca mi khoan, k1=1,0.+ H s iu chnh k2 ph thuc chiu su khoan(bng
5.87-TL2), k2=1,0. Vt = 33.1.1 = 33 m/pht.- Tc quay ca trc chnh: N
= 1000Vt/.D = 1000.33/(3,14.15) = 700,6 vng/pht. Chn tc my: n =750
vng/pht. Tc ct thc t: Vt = .D. n/1000 = 3,14.15.750/1000 =
35,32m/pht. Lng chy dao pht: S = 0,45x750 = 337,5 mm/pht.- Bng thng
k ch ct:Khoan 35,327507,50,45337,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
g) Nguyn cng VII: Khoan l 15 v kho mt F.Ch ct nguyn cng ny ging
nh nguyn cng VI.- Bng thng k ch ct:Khoan 35,327507,50,45337,5
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
h) Nguyn cng VIII: Taro ren M15x1.5 pha mt E.Vi kch thc danh
ngha ca ren M15, bc ren 1.5, ren ct yu cu cp chnh xc thng thng, vt
liu gia cng l gang xm, tra bng 5.188 TL2 ta c vn tc ct ren: V =
12x1,1 = 13,2 m/pht. - Bng thng k ch ct:Taro ren13,228011,5420
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
i) Nguyn cng IX: Taro ren M15x1.5 pha mt F.Vi kch thc danh ngha
ca ren M15, bc ren 1.5, ren ct yu cu cp chnh xc thng thng, vt liu
gia cng l gang xm, tra bng 5.188 TL2 ta c vn tc ct ren: V = 12x1,1
= 13,2 m/pht. - Bng thng k ch ct:Taro ren13,228011,5420
Bc CNV(m/pht)n(v/pht)t(mm)S(mm/vg)S(mm/ph)
2.3.9. Tnh ton thi gian gia cng cho tng nguyn cng. - Thi gian
nguyn cng c xc nh theo cng thc: Tct = To + Tp + Tpv + Ttn. Trong :
Tct : thi gian tng chic (thi gian nguyn cng ); To : thi gian c
bn(thi gian cn thit bin i trc tip hnh dng, kch thc, tnh cht c l ca
chi tit); Tp : thi gian ph(thi gian cn thit ngi cng nhn g, tho chi
tit, m my, mi dao, iu chnh my. . .), Tp = 0,1To; Tpv : thi gian phc
v ch lm vic gm: thi gian phc v k thut, mi dao, iu chnh my . . .,
Tpv = 0,11To; Ttn : thi gian ngh ngi t nhin ca cng nhn, Ttn =
0,05To; Tct = To + 0,1To + 0,11To + 0,05To = 1,26To. - Thi gian c
bn c xc nh theo cng thc: To = (L1 + L2 + L)/(S.n) (pht). Trong : L:
Chiu di b mt gia cng (mm); L1: Chiu di n dao (mm); L2: Chiu di thot
dao (mm); S: Lng chy dao vng / hnh trnh kp; n: S vng quay hay hnh
trnh kp/pht.Nguyn cng I: Bc1: Tin th v bn tinh mt l 72.Tin th.Ch ct
ca bc cng ngh ny l: S = 0,4 mm/vng. t = 1,5 mm. n = 235
vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L + L2).i/(S.n).Trong : S
ln gia cng i = 1. L = 30 mm . L1 = t.cotg + (0,5 n 2) mm. L1
=1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 = 2,5 mm. L2 = 3
mm.
T01 = pht.Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,3 mm/vng;
t = 1 mm; n = 300 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1; L = 30 mm; L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (0,377+0,39) = 0,966 pht.Bc 2:
Tin th v bn tinh mt A, B. Tin th: Cc thng s ch ct: S = 1mm/vng. t =
1,5 mm. n = 37,5 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 225 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 =
2,5 mm. L2 = 3 mm.
T01 = pht.Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng. t
= 1 mm. n = 60 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 225 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (6,15+5,49) = 14,66 pht.Nguyn cng
II: Tin th v bn tinh mt C, D.- Mt C:*Tin th:Cc thng s ch ct: S =
1mm/vng. t = 1,5 mm. n = 37,5 vng/pht.Theo bng 5.7TL[3] c: To = (L1
+ L + L2).i/(S.n).Trong : S ln gia cng i = 1. L = 35 mm . L1 =
t.cotg + (0,5 n 2) mm. L1 =1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm.
Chn L1 = 2,5 mm. L2 = 3 mm.
T01 = pht.*Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng.
t = 1 mm. n = 60 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 35 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (1,08+0,96) = 2,57 pht.- Mt
D:*Tin th:Cc thng s ch ct: S = 1mm/vng. t = 1,5 mm. n = 37,5
vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L + L2).i/(S.n).Trong : S
ln gia cng i = 1. L = 7 mm . L1 = t.cotg + (0,5 n 2) mm. L1
=1,5.cotg60 + (0,5 n 2) =1,4 n 2,8 mm. Chn L1 = 2,5 mm. L2 = 3
mm.
T01 = pht.*Tin bn tinh:Ch ct ca bc cng ngh ny l: S = 0,7mm/vng.
t = 1 mm. n = 60 vng/pht.Theo bng 5.7TL[3] c: To = (L1 + L +
L2).i/(S.n).Trong : S ln gia cng i = 1. L = 7 mm . L1 = t.cotg +
(0,5 n 2) mm. L1 =1.cotg60 + (0,5 n 2) =1 n 2,5 mm. Chn L1 = 2,5
mm. L2 = 3 mm.
T02 = pht.Tct = 1,26.To = 1,26 (0,333+0,3) = 0,797 pht.Vy tng
thi gian cho nguyn cng ny l: T = 2,57 +0,797 = 3,367 pht.Nguyn cng
III: Khoan doa v taro ren 6 l M10x1,5 mt C.Bc 1: Khoan doa. S =
0,45 mm/vng. t = 5 mm. n =1180 vng/pht.Theo bng 5.6 TL[3] ta c: To
= (L1 + L + L2).i/(S.n)Trong : S ln gia cng i = 1. L = 15 mm . L1 =
0,5d.cotg + (0,5 n 2). L2 = 3 mm.L1 = 0,5.12.cotg 59 +(0,5 n 2),
chn L1 = 5 mm. To = (5 + 15 + 3)/(0,45.1180) = 0,043 pht. Tct =
1,26.To = 0,0542 pht, 6 l nn Tct = 0,325 pht.V dng dng c t hp nn c
th coi thi gian thc hin nguyn cng ny bng 1,5 ln thi gian khoan. T =
0,325.1,5 = 0,4875 pht.Bc 2: Taro ren.Theo bng 5.6 TL3 ta c:
Lcb = Trong : + n: s vng quay thun, n = 420(v/ph). + n1: s vng
quay ca dao khi quay ngc, n1= 800(v/ph). + i: s lng taro, i=1. + L1
= 1 n 3 bc ren chn L1 = 3 mm. + L2 = 2 n 3 bc ren chn L2 = 3 mm. +
S: bc ren, S = 1,5mm.
Tcb = pht.6 l To =6x 0,05 = 0,3 pht. TCT = 1,26x0,3 =0,378
pht.Tng thi gian nguyn cng ny l: T = 0,4875+ 0,378 = 0,8655
pht.Nguyn cng IV: Phay tinh mt A, B.Theo bng 5.7 TL[3] ta c: To =
(L1 + L + L2).i/(S.n) Trong : S ln gia cng i = 1. L = 350 mm. L1 =
{t(D-d)}+ ( 0,5 n 30). L2 = 5 mm. S = 1,8 mm/vng. t = 0,5 mm. n =
750 vng/pht. L1 = {0,5(100-80)}+ ( 0,5 n 30), chn L1 = 6 mm. To =
(350 + 6 + 5).1/(1,8.850) = 0,236 pht. Tct = 1,26.To = 0,297
pht.Nguyn cng V: Tin tinh mt C v D.Ch ct nguyn cng ny l: S = 0,23
mm/vng. t = 0,5 mm. n = 118 vng/pht.Gia cng mt C.Theo bng 5.7TL[3]
c: To = (L1 + L + L2).i/(S.n).Trong : S ln gia cng i = 1. L = 35 mm
. L1 = t.cotg + (0,5 n 2) mm. L1 = 0,5.cotg60 + (0,5 n 2) = 0,8 n
2,3 mm. Chn L1 = 2 mm. L2 = 3 mm.
T01 = pht.Gia cng mt D. L = 7 mm. L1 = 2 mm. L2 = 3 mm.
T02 = pht.Tng thi gian nguyn cng ny l: T = 1,26x(1,474+ 0,442) =
2,414 pht.Nguyn cng VI: Khoan v kho mt E.Nguyn cng ny dng dng c t
hp khoan v kho mt nn vic tnh thi gian gia cng c th tnh nh khi khoan
nhng ta c th thm chiu di gia cng mt lng bng ng chiu dy cn kho mt. S
= 0,45 mm/vng. t = 7,5 mm. n = 750 vng/pht.Theo bng 5.6 TL[3] ta c:
To = (L1 + L + L2).i/(S.n)Trong : S ln gia cng i = 1. L = 30 mm .
L1 = 0,5d.cotg + (0,5 n 2). L2 = 3 mm.L1 = 0,5.15.cotg 59 +(0,5 n
2), chn L1 = 5 mm To = (5 + 30 + 3)/(0,45.750) = 0,113 pht. T =
1,26.T0 = 1,26.0,113 = 0,142 pht.Nguyn cng 7: Khoan v kho mt F.Thi
gian gia cng ging nh nguyn cng 6.T = 1,26.T0 = 1,26.0,113 = 0,142
pht.Nguyn cng 8: Taro ren M15x1,5 pha mt E.Theo bng 5.6 TL3 ta
c:
Lcb = Trong : + n: s vng quay thun, n = 420(v/ph). + n1: s vng
quay ca dao khi quay ngc, n1= 800(v/ph). + i: s lng taro, i=1. + L1
= 1 n 3 bc ren chn L1 = 3 mm. + L2 = 2 n 3 bc ren chn L2 = 3 mm. +
S: bc ren, S = 1,5mm.
Tcb = pht. TCT = 1,26x0,103 =0,13pht.Nguyn cng IX: Taro ren
M15x1,5 pha mt F.Thi gian gia cng ging nh nguyn cng 8. TCT =
1,26x0,103 =0,13pht.
III/ Thit k g cho mt s nguyn cng.Yu cu chung vi cc g my:Cht lng
v nng sut ca qu trnh gia cng ph thuc rt nhiu vo trang thit b cng
ngh ca nguyn cng, trong g cc loi c tm quan trng c bit. Trong sn xut
hng lot ln v hng khi, nng cao nng sut v cht lng ca qa trnh gia cng,
ngi ta s dng g g t phi ln my. V vy c th tng tng phi v g l mt chi
tit tng hp cho php g t nhanh v chnh xc khi gia cng. g trong ch to
my c gi l cc c cu ph, s dng khi thc hin cc nguyn cng gia cng c, lp
rp v kim tra. Tu thuc vo chc nng, g c phn chia thnh nhiu loi nh g
my, g kp cht dng c ct, g lp rp, g kim tra v g khc. do vy g c thit k
phi t c cc tiu ch c bn nh s dng thun tin, tc ng nhanh, bo m chnh xc
yu cu ca nguyn cng, c an ton cao, kt cu n gin, r tin, d sa cha thay
th v iu chnh.Cc phn t c bn ca g: Thn g; Cc phn t nh v; C cu kp cht;
C cu dn hng; C cu so dao; Cc c cu ph khc.2.3.1. Thit k g cho nguyn
cng 5 ca chi tit s 4.y l nguyn cng tin tinh mt lp ghp C, D.a, S nh
v v kp cht nguyn cng ny nh sau:
b, Tnh lc kp cn thit.S t lc ln chi tit nh sau:
Cc thnh phn lc tc dng ln chi tit:Lc ct P c phn tch thnh cc thnh
phn: Px; Py; Pz.Lc kp cht W.Cc thnh phn lc c tnh nh sau: P X,Y,Z =
10.CP.tx.Sy.Vn.kp.Thnh phn PX: + Cp v cc s m tra bng 5.23 TL2 ta c:
Cp = 46; x = 1; y = 0,4; n = 0. + KP: H s iu chnh ph thuc vo cc iu
kin gia cng c th KP = KMp.Kp.Kp.Kp.Krp, tra bng 5.9, 5.10 v 5.22
TL2 ta c: KMV = 1; Kp = 1; Kp = 1,4; Kp = 0,85; Krp = 1. KP =
1x1x1,4x0,85x1 = 1,19. vy Px = 10x46x0,61x0,230,4x158,60x1,19 =
182,442(N).Thnh phn PY: + Cp v cc s m tra bng 5.23 TL2 ta c: Cp =
54; x = 0,9; y = 0,75; n = 0. + KP: H s iu chnh ph thuc vo cc iu
kin gia cng c th KP = KMp.Kp.Kp.Kp.Krp, tra bng 5.9, 5.10 v 5.22
TL2 ta c: KMV = 1; Kp = 1; Kp = 1,4; Kp = 1,25; Krp = 1. KP =
1x1x1,4x1,25x1 = 1,75. vy Py = 10x54x0,60,9x0,230,75x158,60x1,75 =
198,18(N).Thnh phn PZ: + Cp v cc s m tra bng 5.23 TL2 ta c: Cp =
92; x = 1; y = 0,75; n = 0. + KP: H s iu chnh ph thuc vo cc iu kin
gia cng c th KP = KMp.Kp.Kp.Kp.Krp, tra bng 5.9, 5.10 v 5.22 TL2 ta
c: KMV = 1; Kp = 1; Kp = 1,1; Kp = 1; Krp = 1. KP = 1x1x1,1x1x1 =
1,1. vy Pz = 10x92x0,61x0,230,75x158,60x1,1 = 201,66(N).Momen ma st
do lc kp gy ra nh sau: Mms = 210.2W.f (N.mm).T s lc ta thy rng kh
nng lc ct c kh nng gy ra xoay chi tit quanh trc l nguy him nht. V
vy ta s tnh lc kp ca chi tit theo kh nng chng xoay ny.Phng trnh cn
bng lc nh sau:225.Pz = Mms = 210.2W.f.Vi f l h s ma st gia chi tit
v phin t, gi tr ca f c th tra theo bng 7.7 TL4, f = 0,16. W =
225.Pz/(210.2.0,16) = 225.201,66/(420.0,16) = 675,2 N. m bo an ton
ta thm h s an ton K, h s ny c th c tnh ton da vo cc bng tra nh
sau:
K= K0: h s an ton nh mc K0=1,5 K1: h s lm tng lc ct nh hng ca cc
nhp nh b mt phi th khi gia cng K1= 1. K2: h s tnh n trng hp lm tng
lc ct do dao mn K2=1,6. K3: h s tng lc ct khi gia cng gin on K3 =
1. K4: h s tnh n sai s ca c cu kp bng tay K4 = 1,2. K5: h s tnh n
mc thun li ca c cu kp bng tay K5 = 1. K6: h s tnh n m men lm quay
chi tit K6= 1,5.
K = 1,5.1.1,6.1.1,2.1.1,5 = 4,32. W = 4,32.675,2 = 2916,8
N.c.Thit k c cu ca g : * C cu kp cht: ta s dng c cu kp cht bng n
kp. Chn chiu di cnh tay n hai pha l nh nhau v bng l.
llWWQ T s lc ta c th tnh c lc kp Q cn thit nh sau:
- Tnh lc kp Q do ren to ra: Q= Q = 2.W = 2.2916,8 = 5833,6
(N).
- ng knh bu lng d= (mm). Tra bng 8.50 TL2v 8.51 TL2 ta c ng knh
bu lng d = 16 mm.Cc c cu khc ca g chn theo cc bng tra trong TL4 v c
ly sao cho ph hp vi kch thc ca bn my v chi tit gia cng.d.Xc nh sai
s ch to cho php ca g : Sai s ch to cho php ca g c tnh bng cng thc
:
Trong :
: sai s g t c ly bng /3 vi l dung sai nguyn cng = 200 .
= 200/3 = 66,6.
: sai s chun, = 0 do nguyn cng ny chun nh v v chun kch thc trng
nhau.
: sai s kp cht c tra theo bng 3.14TL4, vi b mt qua gia cng th =
40 .
: sai s do mn g :
: l h s ph thuc kt cu nh v = 0,3. N: s lng chi tit oc gia cng
trn g N= 1000.
.
: sai s iu chnh = 30theo bng 7.9 TL4.
= 66,62- (402+9,52+302) = 432 .e. iu kin k thut ca g:iu kin k
thut ca g bao gm nhm b mt lm vic ca g, sai s v song song v vung gc
gia cc phn t lp ghp ca g, cng ca cc b mt lm vic v mt s yu cu ch to
c bit khc. c th xc nh c song song v vung gc ca cc phn t lp ghp ca g
ta phi da vo sai s ch to ca g tnh ton trn thng qua quan h nh
sau:
= ss2+vg2.Da vo quan h ny ta c th nh ra cc yu cu k thut ca g nh
sau:
khng song song gia mt phin t vi mt y g 0,03/100mm; nhm ca cc b
mt lp rp v nh v Ra= 0,63; cng ca phin t v cht nh v: HRC 4045.2.3.2.
Thit k g cho nguyn cng 3 ca chi tit s 5.y l nguyn cng khoan 6 l
12.a, S nh v v kp cht nguyn cng ny nh sau:
Chi tit c nh v bng mt l v mt u.b. Cc thnh phn lc tc dng ln chi
tit:Khi gia cng l bng phng php khoan th phi chu tc ng ca momen xon
v lc dc trc P0. Vi phng n nh v v kp cht nh trn, lc chy dao v lc kp
cht tc ng cng phng v u c xu hng p phi vo mt t, v vy phng n ny khng
cn lc kp ln. Lc kp ln nht gi cho chi tit khng b xoay xy ra thi im
bt u v kt thc qu trnh khoan. Momen ct M c xu hng lm cho chi tit
xoay quanh ng tm. mun cho chi tit khng b xoay th momen ma st do lc
hng trc P0 v lc kp Q gy ra phi thng momen ct. phng trnh cn bng lc c
dng:
Trong : M: momen xon trn mi khoan do lc ct gy ra; d: ng knh mi
khoan; K: h s an ton; R: khong cch t tm mi khoan n tm chi tit; P0:
lc ct dc trc; f: h s ma st; R1: khong cch t tm phin t ti tm chi
tit.Cc thnh phn lc ct c tnh nh sau:Mx = 10.CM.Dq.Sy.Kp.P0 = 10.Cp.
Dq.Sy.Kp.Tr s Kp c xc nh theo bng 5.9 TL2, Kp = 1.Tr s ca CM, Cp v
cc s m tra theo bng 5.32 TL2, ta c:Momen xon Mx: CM = 0,021; q = 2;
y = 0,8.Lc hng trc Po: Cp = 42,7; q = 1; y = 0,8. Mx=
10.0,021.122.0,450,8.1 = 15,96 Nm. Po = 10.42,7.121.0,450,8.1 =
2705 N.H s an ton K c tnh nh sau:
K= K0: h s an ton nh mc K0=1,5 K1: h s lm tng lc ct nh hng ca cc
nhp nh b mt phi th khi gia cng K1= 1. K2: h s tnh n trng hp lm tng
lc ct do dao mn K2=1,6. K3: h s tng lc ct khi gia cng gin on K3 =
1. K4: h s tnh n sai s ca c cu kp bng tay K4 = 1,2. K5: h s tnh n
mc thun li ca c cu kp bng tay K5 = 1. K6: h s tnh n m men lm quay
chi tit K6= 1,5.
K = 1,5.1.1,6.1.1,2.1.1,5 = 4,32.Vi f l h s ma st gia chi tit v
phin t, gi tr ca f c th tra theo bng 7.7 TL4, f = 0,3.c.Thit k c cu
ca g :Lc kp Q cn thit do bu lng to ra l:
.
Q = 35599 N.
- ng knh bu lng d = (mm). Tra bng 8.51 TL2 ta c ng knh bu lng d
= 10 mm.Cc c cu khc ca g chn theo cc bng tra trong TL4 v c ly sao
cho ph hp vi kch thc ca bn my v chi tit gia cng.d.Xc nh sai s ch to
cho php ca g : Sai s ch to cho php ca g c tnh bng cng thc :
Trong :
: sai s g t c ly bng /3 vi l dung sai nguyn cng = 250
= 250/3 = 83,3; : sai s chun, nguyn cng ny do chun kch thc trng
vi chun nh v l tm l chnh ca chi tit nn sai s chun bng 0;
: sai s kp cht c tra theo bng 3.14TL4, vi b mt qua gia cng th =
40 ;
: sai s do mn g :
: l h s ph thuc kt cu nh v = 0,3. N: s lng chi tit c gia cng trn
g N= 1000.
.
: sai s iu chnh = 30theo bng 7.9 TL4.
= 83,32- (402+9,52+302) = 662 .e. iu kin k thut ca g:iu kin k
thut ca g bao gm nhm b mt lm vic ca g, sai s v song song v vung gc
gia cc phn t lp ghp ca g, cng ca cc b mt lm vic v mt s yu cu ch to
c bit khc. c th xc nh c song song v vung gc ca cc phn t lp ghp ca g
ta phi da vo sai s ch to ca g tnh ton trn thng qua quan h nh
sau:
= ss2+vg2.Da vo quan h ny ta c th nh ra cc yu cu k thut ca g nh
sau:
khng song song gia mt phin t vi mt y g 0,03/100mm; nhm ca cc b
mt lp rp v nh v Ra= 0,63; cng ca phin t v cht nh v: HRC 4045.2.3.3.
Thit k g cho nguyn cng 6 ca chi tit s 6.y l nguyn cng khoan v kho
mt bch l du M15x1,5. .a, S nh v v kp cht nguyn cng ny nh sau:
Chi tit c nh v 6 bc t do bng mt y, mt l chnh v mt bn ca gn tr
lc. Nguyn cng c thc hin trn my phay ngang 6H82.b. Cc thnh phn lc tc
dng ln chi tit:Khi gia cng l bng phng php khoan th phi chu tc ng ca
momen xon v lc dc trc P0. Lc kp ln nht gi cho chi tit khng b xoay
xy ra thi im bt u v kt thc qu trnh khoan. Momen ct M c xu hng lm
cho chi tit lt quanh ng bin ngoi ca chi tit, cn lc dc trc c xu hng
lm x dch chi tit ra khi v tr nh v. y ta thy rng kh nng chi tit b x
dch v tr l ln hn, v vy ta s tnh lc kp cho kh nng chng trt chi tit.
Mun cho chi tit khng b trt th lc ma st do lc kp Q gy ra phi thng lc
ct dc trc P0, phng trnh cn bng lc c dng: Q.f = P0. m bo an ton ta
thm h s an ton K. Q.f. = P0.K.
Trong : Q: lc kp do bu lng kp to ra; P0: lc ct dc trc; f: h s ma
st;Thnh phn lc ct dc trc c tnh nh sau:P0 = 10.Cp. Dq.Sy.Kp.Tr s Kp
c xc nh theo bng 5.9 TL2, Kp = 1.Tr s ca Cp v cc s m tra theo bng
5.32 TL2, ta c: Cp = 42,7; q = 1; y = 0,8. Po =
10.42,7.151.0,450,8.1 = 3381 N.H s an ton K c tnh nh sau:
K=. K0: h s an ton nh mc K0=1,5 K1: h s lm tng lc ct nh hng ca
cc nhp nh b mt phi th khi gia cng K1= 1. K2: h s tnh n trng hp lm
tng lc ct do dao mn K2=1,6. K3: h s tng lc ct khi gia cng gin on K3
= 1. K4: h s tnh n sai s ca c cu kp bng tay K4 = 1,2. K5: h s tnh n
mc thun li ca c cu kp bng tay K5 = 1. K6: h s tnh n m men lm quay
chi tit K6= 1,5.
K = 1,5.1.1,6.1.1,2.1.1,5 = 4,32.Vi f l h s ma st gia chi tit v
phin t, gi tr ca f c th tra theo bng 7.7 TL4, f = 0,2.c.Thit k c cu
ca g : nguyn cng ny ta dng 2 bulong c cng ng knh kp cht, v vy lc kp
Q c chia u cho 2 bu lng. Nh vy mi bu lng s chu tc dng ca mt lc l
Q/2.Lc kp Q c tnh nh sau:Q = P0.K/f = 3381.4,32/0,2 = 73030 N.
Lc kp do mt bu lng to ra l: Q1 = 36515 N.
- ng knh bu lng d = (mm).Tra bng 8.50 TL2v 8.51 TL2 ta c ng knh
bu lng d = 10 mm.Cc c cu khc ca g chn theo cc bng tra trong TL4 v c
ly sao cho ph hp vi kch thc ca bn my v chi tit gia cng.d.Xc nh sai
s ch to cho php ca g : Sai s ch to cho php ca g c tnh bng cng thc
:
Trong :
: sai s g t c ly bng /3 vi l dung sai nguyn cng = 500 ( dung sai
khong cch t tm l ti mt nh v).
= 500/3 = 166,6; : sai s chun, nguyn cng ny do chun kch thc trng
vi chun nh v nn sai s chun bng 0;
: sai s kp cht c tra theo bng 3.14TL4, vi b mt qua gia cng th =
40 ;
: sai s do mn g :
: l h s ph thuc kt cu nh v = 0,3. N: s lng chi tit c gia cng trn
g N= 1000.
.
: sai s iu chnh = 30theo bng 7.9 TL4.
= 166,62- (402+9,52+302) = 1602 .e. iu kin k thut ca g:iu kin k
thut ca g bao gm nhm b mt lm vic ca g, sai s v song song v vung gc
gia cc phn t lp ghp ca g, cng ca cc b mt lm vic v mt s yu cu ch to
c bit khc. c th xc nh c song song v vung gc ca cc phn t lp ghp ca g
ta phi da vo sai s ch to ca g tnh ton trn thng qua quan h nh
sau:
= ss2+vg2.Da vo quan h ny ta c th nh ra cc yu cu k thut ca g nh
sau:
khng song song gia mt phin t vi mt y g 0,08/100mm; nhm ca cc b
mt lp rp v nh v Ra= 0,63; cng ca phin t v cht nh v: HRC 4045.
Sinh vin: L Bch Dip - 1 - Lp CTM5- K47