NGHIEN CLRJ THIET KE MAY DAM NEN CAM TAY DAN DONG BANG CO CAU THANH TRUYEN - TRUC KHUYU
PGS.TS Tran Van Tuin Khoa Ca khi XSy dung Trudng Dal hge XSy dung
Tdm tat: BSi bSo gidi thidu cae sa dd dpng lue hge, phuang trinh vl phSn vS Idi glal cho eSe may dim din dpng bSng thanh truyin true khu}u. Kit qui eCia cing trinh giiip cac ky su trong vipc tinh toSn, thiit ki eSe mSy dim nin. MSt khSc kit qua nghidn eiru cdn la ea sd di ap dung edng nghd va rung vao tht/c ti san xuit mpt each ed bidu qua
Summary: The paper presents the dynamic schemes, differential equations of movement and solves for consolidation machine, driving by connecting rod crankshaft. The results help engineers to calculate and design vibration machines using In consolidation work with soiL In the other hand, the researched results are bases for applying the impacting technology in production practice effectively.
I . O A T V A N D E
Loai dam n i n d m tay cd khdi lupng <100kg, khi IPm vide d giai doan dam tdch khdi nen, nhd life d l y td tay edng nhdn md dam di chuyin dupc; dam cd ngudn ddng life bing didn hope bing ddng cP dd't trong. Co d u edng tdc cda dam Id d l rung tilp xuc vdi nin khi Idm vide, eo cdu gdy rung, khung dpt ddng co, dpng co, bp truyen, ePe phan td ddn hdi nhu IP xo vd tay gid dieu khiln.
Hinh 1. Md hinh ca hgc dam nin xung kich din dpng bing tbanb truyin - true khu}u.
1. Dim; 2. Dedim;
3. Nin md hinh hoS bing Id xo C2; 4. Phao
TAP CHf KHOA HOC C O N G N G H $ XAY DUNG
sd04/2009
63Cdc hang nude ngodi nhu MIKASA (Nhat), DIAMON BOAD (Ode), LiPn bang Nga da cd d c nghiPn edu che tao d c loai mPy dam rung nen td Idu va d cong nghd san xudt on dinh, dat tinh chuyen mdn hod eao. O Viet Nam, chua cd co sd nao chinh thdc nghien cifu dua ra d e tinh loan thief k l mpt d c h bdi ban va tuong ddi day dd 151. Thdi gian gan ddy, Tong cong ty Co khi xPy dung Viet Nam Id cP sd che tao mdy xdy dung lan dau tien de cpp tdi vide chd tao bing d c h md phong d c mdy ddm nen d m lay.
Bdi bdo nay nhim gdp phan lam sang td ve ly thuyet d l tinh t d n thiet ke lopi may dam nen d m tay dan ddng bing cd d u thanh fruyen - true khuyu.
2. MO HINH CO HOC, PHUONG TRINH VI PHAN VA L d i GIAI KHI DAM TACH KHOI NEN Bdi todn va rung kinh diln sd dung ly thuyet va cham Niuton cd thdi gian va cham gin bing kbdng khi nen IP tuyet ddi edng. Vdi nen khdng phli tuypt ddi cdng thi qua trinh Idm chpt d n luu y:
ThU nhit \a sif thay doi tinh chat eo ly cda nen. Trong qua frinh Idm chpt, coi nen Id mdi IrUdng ddn nhdt, qua sdng vd tan sd xung va cham d l cd I h l danh gid dupe hidu qua IPm chpt.
ThUhai IP md hinh md ta qua trinh ldm chpt phai phan Pnh ddng phUOng trinh chuyin dpng cda bin IhPn may dam. Khi nghien cdu dpng life hpc cda may dam, de b l o dam ca hai chd y tren IP rat khd thuc hien vi khi may vP nen tie'p xde nhau fhi phupng trinh chuyen ddng cda may se Id dieu kien bien cda phuong trinh truyen sdng trong nen. Bdi vpy, don gian hon la eoi nin IS mpt phin tCr eua md hinh ca hgc mSy khi nghien cdu dpng life hpe mdy va nghien edu nhd phuong phap giai tich va thuc nghipm. Do kieh thudc dam (1) Idn hon nhieu (hinhl) dp Idn mpt lan va cham gida de dam (2) vP nen, cho ndn cd I h l bd qua life d n thanh ben cda d l dam vdi nen.
Life d n chinh khi va cham thing ddng dupe md hinh hod bdng Id xo (3), dp cisng C2 gin trdn phao (4) cd luc ma sSt khd gitifa phan dd't Idn vdi xung quanh.
Oon gian hon d Id md ta sif anh hudng cda nen tdi dpng life hpc cda dam bing mdi tuong tac giiJfa dam va n i n thdng qua kit qua cud'i cdng ma khdng d n quan tam tdi fodn bp qua trinh tuong tac; kef qua cud'i eung thdng qua 3 tham sd Id thdi gian va cham hay thdi gian dam vd nen cdng dao ddng ( A / ) ; top dp dam tai thdi diem tach khdi nen; td'c dp dam fai thdi dilm tdch khdi n i n . Cdc tham sd ndy dupc xSc djnh bing tht/e nghipm.
Khi dam tdch khdi nen, ta cd top dp b, (hinh 1). G i l frj ndy thudng rat nhd so vdi dp djch chuyin cda dam trong khdng khi, cho ndn cd t h i coi />, = 0 . Theo ly thuylt va cham Niuton (Af -> 0), td'c dp sau va cham (x-,^) dupe tinh nhu sau:
x,^{t, + At) = -Rx,Ato) (1) Trong dd: to - thdi dilm trude va cham gida dam va nen; i,.(f|,) - tdc dp trudc va cham; Af - thdi
gian va cham; 0<R<\ - he sd phuc hdi van td'c eua nen.
De dang thay ring; i,_(fo) < 0; *,,(/„ -1- Af) > 0 , dam bao cho ^ > 0.
K i t qua IP chdng ta cd bdc tranh chuyin dpng cua dam nhu sau:
Khi X2 > 0, phuong trinh vi phdn chuyen ddng don gian nhat cda dam se Id:
mJCj +mg = F^Cos(eot + rp) (2)
Trong dd: m - khdi lupng may dam; x,- dich chuyin cda dam; co - tan sd gde; F^;q> - life kieh rung vp gde Ipch pha dao dpng.
Khi thiel kd may lam viec vdi van tde va cham Idn nhd't frong mien on djnh vdi sif thay doi cPc thdng sd co ly cda nen thi mo hinh co hpc duoc md fa hpp ly bing hinh 1
Gia thidt t i n hao nPng lupng ch? do qud frinh va cham Id chinh (thudng chilm 80% edng sudt dpng co), phuong frinh vi phPn md t l ehuyen dpng gida hai lan va chpm eda dam nhu sau;
m'x2 + Cx^ = F^ cos ((»f -I- ip) (3) MP hinh dupc frinh bPy d hinh 1 cd life kieh thieh F^cos{(ot + ip), vdi F^=Cxf„ =C.r;
trong dd; r - ban kinh true khuyu; co - tan sd gde; ip- gde lech pha ban dau, theo /8/ cd I h l chpn cp gid trj bat ky, eho nen ed I h l dua tp vao ngay phuong trinh ban dau cho thupn lien nghiPn cifu. O l ket qua nhdn dupc long qudt hon, chdng la dua ve phuong trinh vi phdn ehuyin ddng khdng thd nguydn nhd cdch bien doi sau:
T = o)t. ^ = mco^x^ IF^
Cd t h i viet lal (3) nhU sau; 4 + 7^4 = cos{r + rp) yjb^ - 4ac vdi r = -^ = ~ ^ / ~ (^)
CO Q}\m
Chd y; 4 Id dao hdm theo r. mudn fim Xj can Idy dao hPm cda hdm hpp, vi du X, X, ... „ mro X, ,; meo x, mrox,
= - i - = -I.Vay 4 = — — ^ ^ 4 r =
••| ^ mro'x., ^rrix^ ^.^^ 4F. (5) ' ' F^co F„ ' m
Nghidm tong qudt cda (4) ed dpng: 4 = acos(/T - tp) - - — - ^ c o s ( r -i- cp) (6)
Trong dd; acos(yT-ip) - nghidm ting quit cda phuong frinh thuan nhat;
cos(r + cp) - nghidm rieng cda (4). L i y dpo hdm (6) theo r ta ed:
1-r
4--ays\n{jr-\p)-^ 5-sin(r-i-^) (7)
Sd dung phuong phdp do Ouphinh d l xuat 1918 de giai (4) - phuang phap khSu nghipm di tim d c hd sd a, <p, tp. Chpn gde thdi gian r = 0 ; x^ = ATQ khi vdt bit diu tSch khdi n i n va ddp. Oilu kidn d i u se Id;
4 = 4.=^o=^'il=-Rl (8)
F
TAP CHf KHOA HOC CONG NGH$ XAY DUNG sd04/2009 6 5
Trong dd (+) bilu thj sau va dpp; (-) bilu thj tn/dc va dap. Thay (8) vdo (6) vP (7) ta dupe he phuong trinh;
a cos 1/ r cos (p = c,,
u^sin ip + rsin ^ = -R;_
1+r
(9)
Hai phuong trinh d 4 an sd a, tp, tp, 4- chua biet. Oe d them 2 phuong trinh nda d n xel dieu kipn bien, cudi mdl chu ky khi T = 2mj (L> = \.2,3....N) co:
4 = 4_=4,-4 = 4-
Thay (10) vdo (6) vd (7) ta dupe:
acosil^vy-tp) -cosip = 4o I
-a)'C0s(2^u}'-ip) + ^-sin <p = 4-
(10)
(11)
Trong do: u - sd vdng quay eda true khuyu khi ed mpt va cham. Thifc te ngudi fa quan tPm ehd dp IPm vipe mdt vdng quay, mpt va cham, cd nghTa L> = I . Gill (9), (11) la dupc k i t qua sau:
ip = nyv ; a = - -^^— ; sin9) = — i \ - R)[\ -y')4 ;cos^ = ( l - / " ) 2>'sinD;r7' 2
/ = [(l+^)cotg^7tJ ^ 2_
(\-R)r •- (l-/?)(l + /^=)
*./.|j^-4=
{^-R)ft
•4o (12)
T h i (12) vdo (6) fa nhan dupc quy luat chuyin ddng cda co he. O l ehuyin ddng ton fai I n dinh thi rd rdng 7 = -^ , 4a ^ Phai d gidi han nhdt dmh. Td (12) ta thdy ngay bilu thdc
0)
trong d n phai khdng dm, cd nghTa;
•^L_,:,o^^=.-A±/^
(Diiu kipn thU nhit) (13)Trong mdf chu ky 0 < r < 2;!ri; fhi 4 -4o v' 9'^ thief nen va dpp khdng djeh ehuyin.
acos{/T-ip) -COS{T + IP)<4O (Diiukipn thUhai) (14)
Neu dieu kidn (14) lay dau (=) cd nghTa ndn chiu va dap vd van td'c phai qua 0 d l d i i ddu, thdi gian;
0<T.<2rru: t = T,
; . / \ ' • / \ n (Dieu kidn thU ba)
^=aysm[/T,-ip) -sm[T.+ip) = 0 *
(15)
Nghien cifu I n dinh cda hp bing phuong phap anh xa dilm ISl, ed dieu kien rdng budc thd tif '
(l -R-)sin^7a>y + -—^cos^ rrvy-2{\ + Rf > - X - s i n 2 ^ u y (16)
Xet tidp bing cdch lay dao hdm K _ j vd cho triet tidu:
( l - / ? ) ( l + / ^ )
'-'iiPTf-'''
-0 (17)«,
Triln khai (17) ta nhdn duoc 4„ = —^ de 4' = 0 (18)
Thay (18) vdo 4- d (12) ta dupe vSn tdc trudc va cham Idn nhd't Id;
"^^"^- = 0 1 ^ '^^)
Khi da bilt dUOc van td'c trudc va cham, cd f h l finh cdng suit cho e h l dp IPm vide eda mdy mpt vdng quay true khuyu mdf va cham, theo / 8, fr. 304/ nhusau;
j^i'odiam ^ m(xl_-xl^)0}
max . \^^f
Cdng sud't ddng co duoc finh nhu sau: Nj. = - ^ — ^ — (21)
n
Trong dd: 7 = 0,9 - hidu suit truyen ddng.
3.TfNH TOAN THIET K ^ M A Y
o l thid't kd dam cd f h l ehpn so dd hinh 1. Phuong frinh ehuyin dpng gida hai lan va cham cd f h l vilt: TMJCJ -I- CXJ = £„ cos(<a/ + tp). (••)
Chdng fa dpc bidt lifu y trudng hpp khe hd va dap x^^^^' ^^"^ "^"^ '''^" "®" ^^ ^''^^ khi khdi ddng may, fay gid d n phai ndng dam di cho life d n g cda Id xo can bing vdi trpng lupng dim. Trudng hpp d l dam fif do n i m tren n i n thi frong phuong frinh vi phdn chuyin dpng (") cd thdnh phin trpng lupng may, bPi todn frd nen phdc tap hon nhilu. Mpt khde, khi x^^ = 0 hd cd kha nang ding thdi, dd Id tinh chd't cda hd tuydn tinh. Bdi vpy, ta chpn thief ke may lam vide vdi khe hd .x^, = 0 vd vdi e h l dp life dap Idn nhdt - c h i dp cdng hudng;
2 f ma\4.=- ^ kill 4.=-^ = 0
(\-R){\-r) \-/
Khi bilt max^. cho phdp ta chuyin ve i , , max cd thd nguyen nhd edng thdc (5);
TAP CHf KHOA HOC CONG NGH$ XAY DUNG sd04/2009 67
4 F f
^^-^ De 4^= - ^ = 0 thi / = 0, /" cd dupe fd (12):
- I - ^ - ^ u , -.
F^ moj 1 - y~
{\ + R) CotgTtuy
0 - ^ ) ( i - r ) "
hay CotgKuy = Q^f7ruy = — + k7r (ft = 0.1,2...)
Chpn dpng co loai ed sd vdng quay 560 v/ph va chpn che dp Idm viee 1 vdng quay true khuyu cd mdf va cham, cd nghTa u = 1, ta cd;
;:7 = — -i-ft;r->;' = --i-ft (22)
Vdy de thoi man (22) khi: ft = 0 thi ;' = 1/2 hay ^ = - ; k = 1 thi / = 3/2 CO 2
Trong bilu thdc (18) de 4 c d nghTa thi I > ; ' > 0. Vdy he ch? cd nghiPm I n dinh; —^ = - 0) 2
H a y / = - , / - = — =-!-vd C = /?)>''«= (23) (0\m CO 2
Trong dd; C - dp cimg Id xo; eo - tdc dp gde. B i l l ; ' = - , chpn m . 3.1 Vi du tinh todn
Difa vPo dpc tinh ky thudt cda mpt d i m cdc cd s i n fren thj frUdng d l finh toan kilm fra. Vi du chpn dim cdc cCia Nhpt, mSc MTR-60S dung dpng ca xSng cd dpc tinh ky thupt nhu sau:
Tin siva cham n = 560 lin/phut;co = — = — x S 9 r a d I s . ; hSnh trinhx^ =r = A5(mm);
30 30. "' li/c dpp 700 (kG/llan); ting trgng lugng 62 (kG). Dpng ca xSng loal Rdbin EC08G, cdng suit
3,5-4 mS It/c, tuang duang 3,5x0,75= 2,6KW; khoi lugng 7,4kg.
Gia thilt khdi lupng m bing khdi IUpng vd dam, ta cd m = — ^ — ^ = 21,3kg. Khi thilt k l so bp, chpn m = 35ftg ; fan sd gde cda true khuyu Id (a = 59radIs.
Gid trj ndy x " " cd f h l finh nhd bilu thdc (5), (19):
meo (\-R)(]-r'')' meo
Trong dd: y = - ; /? = (0 - 1 ) ; x^, = 0,045m; long dp cdng cda Id xo C tinh theo bilu thdc (23):
C = m / V = 3 5 f - 1 x 5 9 ' = 3 0 . 4 5 9 A f / «
Thay d c gia tri trPn vdo bieu thdc (24) ta dupc bang sau, trong dd ed d e gid trj van td'c va cham Idn nhdt phu thupc vdo dpc tomg cho ti'nh eo ly cda nen (R):
1. Tinh edng sudt t i n hao d n thiet do va cham, nhd bieu thdc (20) eho d c trUdng hpp:
m(xl_-xlJeo + R = 0 , 0 1 ; i , . = 1,77m/s;A';'
+ R = 0,8, A-,_ = 8,9m/s; A^^"
4;r
,,(1,77^-(0,01 xL77)^)59 ^,^
35 = 5I5M'
4x3,14
m(x|^-x|j6> (8,9--(0.8x8,9)-)59 4;r = 35
4x3,14 = 4688w 1,2Af'"''"'"
2. Cdng suat dpng cP cPn Id N^, = ^ ^ —
TT
1 2 3 4
C (N/m)
30459 30459 30459 30459
m (Kg)
35 35 35 35
(m)
0,045 0,045 0,045 0,045
CO
(rad/s)
59 59 59 59
R
0,01 0,45 0,55
0,80 x^_
(m/s) 1,77 3,20
3,96 8,90
\jva<.hai}i max
(W) 515 1360 1802 4688
1 2)V"°'*°"
1 687 1820 2400 6250 3.2 Nhan xdt
- Nhin vdo bang tren thdy ring may dam xung kich, mdc MTR-60S Idm vide phd hpp vdi loai nen c d O < ^ < 0 , 5 5 .
- Qua trinh xdc dinh ede thdng sd eho d bang trdn ed f h l Idm cd sd de finh fodn thilt k l so bd mdy mdi.
Npi dung cdng trinh quan fdm chd ye'u tdi bdi todn thie't ke so bp may dam lam viec d chd dp gan cpng hudng, lim dupe dp cimg can thie't cda Id xo vd dam bao cho Id xo khdng bj hdng trong qud trinh Idm viee. Cdc thdng sd mdy che tpo cdng nghiep dupc ehinh xae hod qua Ihd nghidm.
Cdc vd'n de lidn quan ldi qua trinh vd cdng nghd Idm chpt nen cd I h l tham khao thdm tai lipu 161 d l sd dung may dam sao cho hieu qua nhdt.
Khi sd dung ngudn dpng life IP dpng co dien, anh hudng ngupc td cP he va rung cd dpc trung phi tuyin manh tdi ddng co ed cdng sudt gidi han ed f h l tham khao vP sd dung fPi lieu /9/
vd /IO/ d l nghien cdu va khao sat.
Tai lieu tham khao
1. Trdn Van Tudn. Ca sd tinh cdng suit gSy rung bSng khoi Idch tSm. TT Cdng trinh khoa hpc.
Dpi hpc Xdy dung sd 3/2000; trang 66-70.
2. Trdn Van Tudn, Oo Sanh, Phan Vdn Thao. Khao sSt dpng li/c hge hp va rung 1 bpc tUdo tren nin dSn hii. Tap chi Co hpc - 4/1994, tr.44-48.
3. Tran VPn Tudn. Khao sSt dpng hgc dim nin xung kieh tu di ehuyin, lap ehi Cau dUdng sd 4/2002, trang 30-33.
TAP CHf KHOA HOC C O N G N G H S XAY DUNG SO 04/2009 69
4. Tran VPn Tuan. Nghidn citu eSch xSc djnh gia trj lue can vS giam chin cda eSc mSy rung khi ISm vipc. TT edng frinh KHCN 1/2002.
5. Nguyen Van Thai. Nghien ciru thiit ki, chi tao cae thiit bj thi edng cim tay. Bdo cdo f l n g ke't de ldi cap Bp XPy dung. Ma sd RDN 10-01, Nam 2003.
6. BaywaHa BA. M flpyrne. BudpaiiuoHUbie MaaiuHbi e empoumenbcmee u npouseodcmee cmpoumenbHbix mamepuanoe, MoeKBa,1970.
7 BayiuiaHa 8 A . BbixoBCKnii M.M. BudpauuoHHbie MauiuHbi u npoueccbt e empoumenbcmee, MocKBa - 1977.
8 BbixoBCKMii M M Teopun Bu6paL(U0HH0u mexnuKU, M, 1969.
9 KoHOHeHKO B O KonedamenbHbte cucmeMbt e oapaHunenHbtM eosdyiKddeHHueM. M,1964.
10 AHanumunecKue uedmodbt HenuneOHOu tAexanuKU. KMEB,1981.
