NGHIEN CUfU-TRAOeCl
THIGT KG MAY DO GOC NGHIGNG BANH RANG TRU KIGU CO DIGN TUf
DESIGN O F T H E DEVICE FOR MEASURING T H E ANGLE OF INCLINATION OF CYLINDRICAL GEARS W I T H HELICAL TEETH IN A MECHATRONICS A P P R O A C H
Pham Thanh Long
Khoa Cd khi, Trfldng Dgi hpc Ky thuat Cdng nghiep - Dai hpc Thai Nguyen
TOM TAT
Trong khdu sdn xudt hoac kiem tra bdnh rdng tru rdng nghieng, goc nghieng Id thdng so quan trong cdn nhdn biet vdi dd ehinh xdc cao. Cdc mdy CMM co the thda mdn yeu cdu ndy, song do cdng khdng phdi la chUc ndng vdn cd cua nd. Mat khdc, mdy rdt ddt tien, khdng phdi cd sd sdn xudt ndo cdng dUdc trang bi. Bdi bdo ndy gidi thieu mgt mdy chuyen dung do gdc nghieng bdnh rdng kieu cd dien tU, trong dd trinh bdy edc tinh todn cdn bdn ve do chinh xdc toi thieu cua cdc cdm bien ldm viec phdi hdp dUa tren ddng hgc mdy do. Vidu trinh bdyeho thdycd the chu ddng dieu chinh do chinh xdc ciia mdy thiet ke theo nhu cdu sdn xudt.
ABSTRACT
In the production or testing cylindrical gears with helical teeth, the angle of inclination is a very important parameter that needs to be identified with high accuracy The CMM machines can meet this re- quirement, however this work is not their inherent function and the machines are very expensive also. This paper introduces a single purpose machine for measuring the angle of inclination of cylindrical gears with helical teeth in a mechatronics approach, including fundamental calculation of the minimum accuracy of the sensors that work eoordinately based on kinematics of the measurement device. The example in this paper shows that we can adjust the accuracy of the designed machine flexibly according to the production demand.
T A P r H i r r f KHf Vl|T NAM V So 7 (Thing 7 nam 2012)
NGHIEN Cl/U-TRAO DOI
I.DATVANDE
Banh rang cd mgt trong nginh Cd khi lU rat sdm vdi chflc ning truyen chuyin ddng quay ehinh xie, bien ddi edng sii.M vi hfldng chuyfi'n dpng tren cd sd thay ddi tl sd truyen
Neu nhfl irongvicc tliicl kc mdi bp truyen, gdc nghieng cua banh ring nghieng duoe xic dinh thed ly thuyet thi trong vi|c thiet Ki- Igi hoac kilm tra banh ring di gia edng, vi^c xic dinh chinh xic gde nghieng tfl mpt nguyen mau cd sin gap nhicii khd khan ve thilt bi do.
6 banh rang trp rang nghieng khi gia cdng, ngfldi ta quit dfldng sinh thin khai theo dfldng chuin li dfldng xoin vit tru de tgo hinh mil rang. Dfldng xoin vit niy dflpc hinh thinh dpa trin c<( sd phdi hpp hai chuyen dpng la di ehuyl'n dpc Iryc tfldng ddi gifla dao vi phdi banh ring phu hpp vdj mdi vdng quay ciia phdi tren may gia cdng.
Khio sat thi trfldng may do'gdc nghieng banh rang tru trong mpt thdi gian dii, tac gii nhin thay, khich hang thfldng se giii quyet van de theo hai hfldng:
- Do kiem tflong ddi vdi cic dung cu thu edng (sfl dung thfldc kep vdi cic binh rang cd gdc nghieng dUdi 150, hoac lan vit len giay vdi cic binh rang cd gdc nghieng tren 150) sau dd hi?u chinh ket qui do theo tieu chuan;
- Do bing cic miy do tpa dp thdng qua mdt chuong trinh xU ly ket qua khdng chinh hang.
Cic phfldng phip niy deu cd diem khd chap nhan d gde dp kinh tl hoae ky thuat vi him chfla sai sd phfldng phip dd (ching hgn khi do chieu dii dudng chuan xoan vit tru bang thfldc kep da liy day thay cho cung), hoac trang bi khdng chuyen dung, khd van hinh vi dat tien (trong trfldng hpp phii dung tdi miy CMM).
Xuat phit tfl thflc te tren, trong bai bio niy chung tdi gidi thieu may do gde nghieng banh ring chuyen dung kieu cd dien tfl, mpt phUdng in giai quyet dUdc cac yeu td kinh te va ky thuit cua phep do gdc nghieng.
2. THIET KE DONG HOC MAY DO a. Dac diem tao hinh mat rang cua banh rang tru rang nghieng
Hinh I: Khai trien dudngxodn vit tru Tflc li mpt chat diem thudc dung cu cat se ed hai bac tU do tUdng ddi so vdi phdi li quay quanh true phdi va tinh tien doe true phdi, tuy nhien cd lien ket dpng hpe rang bude gifla hai chuyen ddng niy.
Tren hinh 1, neu dao di chuyen dpc tryc mpt Iflpng AE thi phdi quay di mpt cung BE de hinh thinh dfldng chuan AB.
b. Co sd dong hpc may do
Nguyen tic de thiet ke ddng hpc may do de xuat d day la sfl dpng mpt dau do tiep xuc trong ranh ring, di chuyen theo phfldng sdng song true banh rang dflpc ga quay tfl do tren mpt gii dfl de do chuyen dpng quay cua banh rang do bi dan bcJi chinh gde nghieng hinh thanh sin tren mgt rang.
Khi gia cdng, ti sd truyen cua xich vi sai se quyet dinh gdc nghieng, the hien gian tiep ciia ti sd nay chinh li Iflpng di dpng tinh toin cua khSu diu vi khau cudi (dau dd - banh rang), nlu do dflpc Iflpng di chuyen cua tflng khiu trong quan
TAP CHi CO KHf V I £ T NAM So 7 (Thing 7 nam 2012)
NGHIEN Cflu - TRAO Dpi
he tgo hinh dfldng chuan ehinh la eP sd chinh xac dd, trong dieu kien dp chinh xic ciia ket qui do de tii tao gdc nghieng. dflpc cho trfldc.
Viee do Ifldng chuyen ddng dpc trpc cua dau do Iflpng AE (ehu dpng) va chuyen dpng quay cua phdi BE (bi dpng) vdi dp ehinh xac can thiet se eung cap gdc nghieng chinh xac thdng qua viec tinh h i m toin hpe tang(BE/AE).
Do mat rang d i gia cdng li be mat tinh, viec tiep xuc vdi dau dd di ddng dpc true se chuyen mpt phan nang lUpng cua dau dd qua mat rang thinh chuyen dpng quay ciia phdi vdi hieu suat chap n h i n dfldc, tuy nhien trong sd dd do edn can xac dinh chinh xac dfldng kinh tiep xuc gifla dau dd vi banh rang, dieu nay dupe giai quyet bing mdt cim bien vi tri lam viec ddc lap.
So do nguyen tac m i y do dfldc de xuat nhu hinh ve:
Trinh tU thuan eiia bii toan vdi nhflng dieu ki?n thilt ke cu the dflpc neu ra dfldi day Gdc nghieng [3 theo sd dd tren dflpc tinh theo cdng thflc:
'gib)- EB
>p=^rctg{-—)\
EA
Vdi dp chinh xic yeu ciu li 10 giay tUc li sai so ciia ket qua do gde [3 cho phep tdi da la 10 giay, ddi ra ddn vi dp ta ed dp chinh xie cua gde (3 li:
A^ = J L 3 0.00278" /g( A^) - /g(0,00278") = 0,00004848 3600
Mat khae ham tg{t,)-- CA 1 tfl ket qua tinh dp ehinh xic d tren ta se xac dinh dd ehinh xac tg{Ap) cua EB v i EA theo edng thflc sau:
0
Hinh 2: Sd do nguyin ly mdy do goc nghieng
tg(Ap) = EB'.AEA-+EA-.AEB-
>tg(Ap)'.EA-'=EB-.AEA=+EA=.AEB'; (I)
3. TINH TOAN B O PHAN GIAI CUA CAC CAM BIEN LAM VIEC PHOI H O P a. Bai toan ngi^oic xac dinh do chinh xac cua cac cam bien
Co the thay so do nguyen tac bam sat dong hoc may gia cong banh rang kha don gian, song bai toan phiic tap nhat d day la xac dinh do phan giai cua cam bien do dich chuyen tinh tien (luong AE tren hinh 1) va dp phan giai c i a cam bien do cung BE tren hinh 1 d miJc toi thieu khi chiing lam viec phoi hop v6i nhau de cho ra mgt tham so dan xuat tren co sd phoi h a p hai tham so
Tren may che thu chung toi lay EA= 120mm
EB = a . ^ 360
Trong do d = 150 mm, a o day chpn bang 60°, vi thong thuong goc nghieng cua banh rang tir khoang 20"- 40°, tir do
EB , . 3,14.150 „ ,
= 60.-^ = 78,5mm.
Tit cong thiic (1) thay rang dp chinh xac nho nhat cua doan EA dat duoc khi phep do cung EB CO dp chinh xac tuyet doi (khong co sai so) tutc^
TA P CHf r . n KHf VlftT NA M V S6 7 (Thing 7 nam 2012)
NGHIEN Cflu - TRAO D O I
'^ EB - 0 . ^^^^ ^ llg(A|3)'.EA'^l-A=.AEB'
^lg(Apf.EA'=EB=.AEA;,„ ' I'"
tg(AP).EA" 0.00004848.120' „„„„„„ lo.00004«5=. 120' - 120'.0,0036' „ „„_
AEA - ' = -0.()088'>mm: _ I— ; • O.OOVmm EB 78.5 Y 78,5'
NgUpc lai, dp chinh xac nh6 nhat cua cung
EB dat dupc khi phep do doan EA c6 sai so bSng b. Xac dinh d0 chinh x i c p h i p d o qua b i i toan 0, tClc la EA =0. thuan
=>tg(Ap)M.A' = E A \ A I B ; „ , -" \EB„„ =lg(,\|!)l:A S A E B „ „ =0,00004848,120
.- \1-B„„ =0.00582mm:
Tii hinh 1 co EB la dp dai cung m^ gia tri cam bien 2 do dupc l i g6c a co:
360.A£B,.„
Sa ^ = A£B
360 ;rd
Aa<0,00445" =16,02"
AEA < 0,00889mm
Neu chpn c i m bien do goc quay co dp chinh xac 17 bit thi goc toi thieu ma cam bien con nhan dang dupc la:
360 = 0,00275 131072
vay thoa man yeu cau ve goc be nhat can do
Theo cac lUa chpn d tren thi cam bien do g6c quay co dO phin giai 17 bit, cim bien do di chuyen dau do co dp phan giii 15 bit, dp chinh xic lan lupt 14 0,00275" v i 0,00366 mm. Dp chinh xic cua p h i p tinh Tang dupc tinh theo cong thilc sau:
(2)
g(AP)= EB-AEA' + EA-.AEB\
/ EA'
Mat khae, ducing kinh Idn nhi't co the do dupc la d= 150mm. Vay dp chinh xic nho nhat cua cim bien thtf 2 can dat dupc li:
360.0,00582 . „ „ , , ^ 3,14.150
Vay phai chpn dp chinh xac cua 2 cam bien thoa man dieu kien sau:
Trong do:
EA=120mm, EB = 78,5mm.
AEB = A a . — = 0,00275 ^ i ^ i ^ = 0.0036(mm) 360 360 AEA = 0,00366(ram)
,^(^p^^^78,5-.0,O0366^.120-.O,0O36-^3^^3,„.,
Ap = arctg(3.603 10^) = 0.00206" =7.43"
Vay dp chinh xac dat duoc cua gdc can do la 7.43" dat yeu cau dat ra
L. Cff SO" xir ly so lieu do lirdug
Tin hieu cua 2 cam bien dua ve la so bit tuong img cua dp phan giai cua cim bien. Ta can xay dung ham toan hpc de vi xir ly tinh toan gia tri gdc p.
Vay chpn cam biln do gdc quay cd dp p h i n giai la 17 bit. Tfl dd xic dinh dp chinh xic cua cim bien thU nhat:
AEB = A a . ^ ^ A E B = 0,00275.MillO =
360 360 Tfl cdng thflc (1) cd:
0,0036mm
Gia six tin 17 bit cua encoder do gdc quay banh rang duoc luu vao biln x2, 15 bit cua en- coder do di chuyen dau do dupc lim vao bien xl.
ta can chuyen cac bien do sang gia tri cd don vi do cua cam bien.
Ddi vdi cam bien do gdc quay thi gia trj gdc quay a ciia cam bien la:
TAP C H i CO KHI VIET NAM V Sd 7 (Thang 7 nam 2012)
NGHIEN Cflu-TRAOePi
, 360
a = x 2 . — = 0,00275.x2
* ^ ^ = " ' ^ = 0 ' ' " ' 2 7 5 . x 2 . i l i l = 0,000024.x2d 36U 360 dau do.
Doi v6i cam bien do di chuyen thang cua AE = x l . — = 0.00366.x I 120
raf • " • • • • • " '
1 ^ .
1
U_'^:^r;:.^
nen
^ 1
Tii do suy ra cong thilc tinh goc p cin lap trinh cho vi x i ly la:
C „ ^ ^ BE_0,000024.x2.d AE 0,00366x1
('BE']
AE J
^p-°'4i)
4. CAC THIET BI CAN BAN CUA MAY a. Cam biln do goc quay
Hinh 3: Cdm bien do gdc quay FPCOAO-Ol cua hdng Codechamp
Hinh 4: Cdc thong so cd bdn cua cdm bien goc
b. Cam bien dich chuyen thang
H»i/i 5: Ctim bien dich chuyen thang cua hdng Posichron
n.',u ,11 I M p l u M i ^ M I
l . ' l . - > m . u . t J p l u y t o l i n h
11,11,[I Lu Kc,,.-,,
- i , u l i „ „ i „ u , . , . n , l ( ' , M , - Ml • „ M) IIJII,,,,,
l a i , l . „ I K I l , • m 1 h i i , ' , . v , „ | , h . „ „ . , , l „ k , „ „ g Phijiii v l ; 5 0 0 m , i i 1 lo -() l ( ) ' ! „ l . L02 = ±0 02 % f s P h a m v , < 5 0 l } m m I I U = t U 5 m m L 0 2 M M = ± 0 2 m m
± ( , , m
4 k h o . , i , n c h . n M S c p d-iu ,a 3 n,
Hinh 6: Bdng tham sd cdm bien do dich chuyin thdng
c. Mach cau dieu khien dong cd va hien thi ket qua do len man hinh LCD
Resolution Output Output Interface
± 10" ? , y ic-,a,GuID.:.iCEo.e•le^^•
R33z;
Power supply / Consumption O<J - sv t y t cso mA mo^J Operating temperature
Storage temperature Operating speed Starting torque
rim a o ' t re + 35X f r o m • 55'C i-j * 1Z5-C l?Orpm
£001.10 ^Mmnw
Hinh 7: Mach dieu khien man hinh vd dgng ca dien
d. Bo tri chung cua may do:
HinhS: Viiet ke CAD
T.n.^nf^/^ {(jjl yjf'j. ^ ^ j ^ S5 7 (Thang 7 nam 2012)
NGHIEN ClJfU - TRAO D O I
5. KET LUAN
Xuat phat li( nhu cau thflc te vc thiet bi do gdc nghieng banh rang tru trong s i n xuat, nhom nghien cflu da cho ra ddi mpt thicl bj chuyen dimg d i p flng cAc y^u eau v^ kinh te ky thuit.
D i giii quyet bii toin co ban la chpn dp chinh xic cua eae cim bien cd thfl nguyen khae nhau de dat dflde hieu qua tdi Uu cho ihict k6, tren cd sd dd cd ih^ lao ra cic thiet bj do khic cd dp chinh xac theo yeu cau bing quy trinh tinh toin tUdng tp.
Sin phi'm miy do gde nghieng banh ring ed gia thinh re hdn nhieu so vdi eae may do dfla tren ky thu^t khic, van h i n h de dang, dpc ket qua trpc licp li nhflng Ipi thef Idn khi sfl dpng. • Ngay nhan bai; 01/7/2012
Ngay phan bi?n: 08/7/2012
Ngudi phan bien: PGS, TS. Nguyen Van DU
Tai lieu tham khio
11]. Nguyen Hflu Cong, Ky thuat do lUdng. Tai ban lin thfl nhat, NXB Giao dye. Ha Npi 2000.
12]. Simple techniques for measuring the base helix angle of involute gears, C Innocenti University of Modena and Reggio EmiliaModena, Italy 12 th IFT oMM world Congress, Besaneon, )un 18 -21,2007.
|3]. Townsend, D.R.Dudley's Gear Handbook, McGraw-Hill, NewYork, ISBN 0-07-017903-4. 1992.
(4]. Gear Design, Manufacturing and Inspection Manual, SAE,Warrendale, PA, vol. AE-15, ISBN 1-56091-006- 2, 1990.
15]. Regalado 1. and Lopez R., Reverse Engineering of Pure InvolutcCylindrical Gears Using Conventional Measurement Tools, Gear Technologypp. 32-35, Jan./Feb., 2000.
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