IVid HilMH LY T H U Y E T IVGHIEIXI CIJU AlMH HUCTIMG C H I E U DAI Lum DAO VA DO S A U RAIMH OEIM KHA IMAIXIG TUIMG D A T C U A BO PHAIM
L A I V IV I E C Q U A Y IMGHfCH CUA
I V I A Y D A O R A I M H T R O I M G
IMdlMG IMGHIEP
Nguyin Van Phlt' TOMTAT
Bai bao trinh bay ket qua nghien ciiu xay dung mo hinh toan tren co so mdi quan he cac thong sd vl hinh hpc, dong hoc ciia may dao, thong sd cua ranh dao (be rong, do sau) va mot sd thong sd dac trung ca tinh cua dat Muc tieu chinh cua bai bao nay trinh bay mdi quan he giua chieu dai ciia luoi dao, do sau cua ranh va kha nang tung dat cua phay dao, tir do de xuat pham vi lua chon thong so va bo sung kit cau ciia may dao nhlm dam bao chat lugng ranh dao, nang cao kha nang lam viec cua may dao. Ket qua da xac dinh dugc cac thong so thiet ke de bao dam kha nang dao, tung dat hieu qua, do la: Ung voi goc tung dat thay doi / = 40°- 60° thi chieu dai luoi dao L nlm trong khoang 50-150 mm va do sau ranh dao H = 400 mm. Tuy nhien, de tang nang suit lam viec va dat yeu cau nong hoc, nhat thiet phai lip them tam vet co kha nang dieu chinh kich thuoc phia sau phay dao.
Ngoai ra, ciing voi luoi dao lam nhiem vu elt va tung dat cin bd tri them lu&i hat de tang nang suit tung dat Tir khoa: May dao ranh, klia nang tung dat ciia phay dao.
I. DAT VAN DE
Tao dugc ranh cd the b i n g nhilu loai mIy mdc vl c6ng cu khac nhau, ngugc lai mot loai may cung cd thi tao dugc ranh co kich thuo'C va yeu clu n6ng hoc khac nhau nhd vIo viec dilu chinh cac thong sd lam viec thich hgp. Mot may dIo ranh thong thudng cd the diing d l dao nhung ranh be de d p nude tudi cho cay trdng hoac diing de tieu nude, x l phln; ranh ngan d c loai c6n trimg hoac tao ranh de trdng d c loai cay c6ng nghiep ngln ngly nhu mia, sin vl nhilu loai cay luong thyc khIe tren co sd ap dung phuong phip lam dlt tdi thieu n h l m tang sd thao tie tai viing ranh dIo. Hinh dang, kich thudc vl elc yeu clu nong hgc ciia mdi loai ranh ddi vdi timg loai cay trdng hoac elc yeu clu ky thuat khac tuy vIo cong dung cua ranh dao phu thuoc vIo clu tao vl kich thudc hinh hoc va e h l do dong hgc ciia bg phan cong tic ciia may dao. D l dao ranh b i n g may ngudi ta co the sir dung dang bg phan llm viec chu dong, hi dong hoac dang kit hgp.
Muc dich nghien cim duge d l cap trong bii b i o nly II nham xly dung mdi quan he giffa nang suit dIo vl nang suit tung, dua vIo mdi quan he nly cho phip xac dinh anh hudng lan nhau giQa d c th6ng sd phuc vu c6ng tic thiet k l , che tao va d c budc nghien cim tilp theo.
Bii bio nly trinh bIy ea sd khoa hgc vl phuang phap xay dung m6 hinh toln phuc vu viec xac dinh Inh hudng cua d c th6ng sd llm viec tdi kich thudc cua ranh dIo, can cu vIo yeu clu dac diem cua timg loai ranh cho phep xlc dinh d c th6ng sd ciia bo phan llm viec dang quay chu dong ciia may dIo, phuc vu cho e6ng tic thilt k l c h i tao hoac nghien cuu thuc nghiem tiep theo trong q u i trinh tdi uu hoa che do llm viec eua may v l d l xuat k i t clu mIy dIo.
Sa dd nguyen ly cau tao eiia mIy dIo ranh dang phay dugc trinh bIy b hinh 1. Dudi day II kit qua nghien ciru v l m6 hinh ly thuylt, tinh toln vl qua trinh llm viec ciia luoi dIo phing, ddi vdi phay chu dong quay nghich cd true n l m ngang vu6ng gdc vdi phuong ehuyin dong cua may keo.
II. PHUDIMG P H A P niGHIEN CUU
Tren co sd nghien cim tai lieu, dua ra d c gil thuylt, tir d c gia thuylt tic gil d l xult c6ng thirc tinh toln nang suit cat vl tinh dlt. Lap m6 hinh toln mo ta mdi quan he giu'a nang suit ly thuylt elt va nang suit tung. Su dung cle cong cu toln hoc, ve dd thi khao sit v l mdi quan he giua cac th6ng sd eiia may den k h i nang tung dat cua phay dIo. Tiln hinh dilu tra x l c dinh mot sd dac tinh ca ly ciia dlt th6ng qua thue nghiem trong phdng thi nghiem.
III. KET QUA VA T H A O LUAIU
TS. Truong Dai hoc Hdng Diic.
1. Ca sd xac dinh kha nang cat va tung dat ciia phay dao dang luoi gin tren dia
Nang suit cua may dao dugc xac dinh tren ca sd dua vIo kich thuoc ciia ranh ma may thuc hien dugc
trong mot don vi thdi gian, dugc xac dinh bing c6ng thiie [4]: Q,=V,„BHk,^,nf/s; (1)
Trong dd: f^,, - van tdc llm viec cua may keo, m/s,B - he rong ranh, m;H- do sau ranh dIo, m;
k^^ - he sd toi xdp ciia dlt.
4
1.
2.
3.
4.
5.
6.
7.
Tam vet CInh tim vlt Hop sd Khung may True cae dang Mui xdi sau Phay dIo Lu5i dIo
Hinh 1. Sa dd eau tao mIy dIo ranh dang phay Nang suit elt vl tung dlt tinh toln phay dIo
trong mot don vi thdi gian duge xlc dinh theo cong thiie [4]:
Q.= '--—^,m'ls;{2)
60
Trong dd: Z - sd luoi dIo tren dIa duge cat sau mdt vdng quay cua phay, l/v,F^. - dien tich mat d t ngang khdi dlt tren luoi dIo, nr^;n - van tdc gdc trdng phay dIo, v/ph;L- ehilu dii d t dlt ciia luoi dIo, cm;y - goc giiia tru vl canh eua luoi dIo (ggi la gdc tung dlt) i'^Y
Nghien cuu tmdng hgp phay dIo dudng kinh ldn, khi lam viec hop sd kh6ng cham vIo bd ranh vl can trd qui trinh tung dlt, khoang elch 2 tru d n h luoi dIo quay vl 2 chilu ngugc nhau, hiy theo tinh chat eua dat vl ehl do llm viec cua may ml cd thi tao duge ranh cd bl rong Ion hon hoac be han bl rdng llm viec cua phay dIo. Cd thi xlc dinh gin diing bl rdng ranh dIo B = 2 1 sin ^ . Tir (1) va (2) ta
co:
Q.=
ZLF^n sin y
60 (3)
Theo e6ng thire (3) nang suit tung dat Q2= f{Z,L,F^,n,y){A). Khi tang sd luoi dIo Z thi nang suit g , tang, hiy nhien khi Z tang qui nhieu din tdi sir iin tie trong phay dao. Vi vay, viec bd tri sd lugng luoi dIo tren dia tdt nhlt dua vIo dilu kien khi luoi dIo thir nhlt vira kit thiie elt dlt thi luoi thu hai bit diu cat dat, nhu vay se dim bao tai trgng tie dong len true phay dIo phan bd diu, it gay xung va dap ddi vdi true luoi dIo, van dl nay ciing da duge tie gil de cap d bii bio [4].
Viec xac dinh dien tich mat elt ngang eua khdi dlt tren luoi dIo d n duge dua vIo mdt so gil thuyet, CO sd hinh dang ly thuylt eiia khdi dat tren luoi dIo gdm d c ylu td sau:
- Hinh dang ciia thdi dlt tren luoi dIo phu thugc vi tri xet, kich thude eua luoi dao, ehl do llm viec cua phay dIo vl ca ly tinh cua dlt. Qui trinh luoi dao llm viec gin liln vdi viec elt, nin vl bi be gay thdi khdi mat ddng.
- Hinh dang eiia thdi dat trIn luoi dIo phu thugc ea ban vIo trang thii eiia dat. Neu dat chua bi phi vo' thdi dat cd hinh dang khdi, ngugc lai dlt da duge lam toi so bg thi dlt dang rdi rac nen phan bd tan loan tren luoi dIo, vi vay khdi dat tren luoi dIo ed the roi vl phia tmdc hoac phia sau luoi dIo.
NONG NGHIEP VA PHAT TRIEN NONG THON - SO 4 - THANG 4/2010 41
- Nlu kich thudc vl k i t clu ciing nhu cac thong sd cua may hgp ly se gilm dugc lugng dlt roi khdi luoi dIo.
Cle th6ng sd v l k i t clu, hinh hgc v l ddng hpc eua bg phan llm viec vl tinh chit cua dat cd Inh hudng rlt ldn d i n nang suit cua may vl chat lugng ranh dIo.
Vl ly thuylt dien tich mat elt ngang khdi dlt tren luoi dIo cd the xlc dinh gin diing bing dien tich hinh thang - ABCE dugc mo t l d so dd lam viec (hinh 2).
Viec elt vl tung dlt tren
luoi dIo rlt phuc tap, thue t l hai q u i trinh nly kh6ng t h i tich rdi nhau, vl ly thuylt cd the tich thinh 2 giai doan elt vl nIn I p tren mat luoi dIo d l nghien ciru.
Viec xlc dinh t h i tich khdi dlt tren luoi dIo dugc dua vao nguyen tic can bing ung suit tren d c mat elt cua thdi dlt. Ung suit nen len thdi dlt tir luoi dIo tang din khi canh sic eiia luoi dIo ehuyin dong an sau vIo dlt (tir dilm B d i n C) gay nen iing suit elt len hai mat ben (ABCE) v l mat trudc chiia canh sic ciia luoi dIo tang din. Khi canh sic cua luoi dIo chuyin dong den dilm C img suit nIn tren mat chiia canh CE cua thdi dlt dat cue dai, khi dd img suit elt tren cle mat ben cua thdi dlt dat tdi gidi ban, thdi dlt hi tich rdi khdi mat ddng v l duge nang din len mat dlt cho din khi canh sic eua luoi dIo ra khdi mat ddng, ddng thai thdi dlt b i t diu thue hien chuyen dong tmgt tren luoi dIo vl thuc hien q u i trinh tung dlt.
/
1
/\
\
\
\
0
^'-^_^
A'
0'
__,!><_ ^
-* •
A B
j T? / /
/ irf---/-^,^
/ - B'I
H
Hinh 2. Thdi dat tren luoi dIo khi bat dau tung dat
phay dIo. T h i tich eua khdi dlt tren luoi dIo do hai luoi lien tilp tren ciing mot mat elf (thdi dlt elt) gdm 2 phln: F^ va F, II phln d l t duge cung d p them tir lugng dlt chua duge tung ra khdi ranh dao bdi cle luoi dIo trudc. D l x l c dinh hinh dang mat elt ben cua thdi d l t da gia thuylt thdi dlt trudc luoi dao II ddng nhlt, luc tic ddng len hai mat ben cua thdi dat tren luoi dIo ed phuong thing dung, mat cat trudc eiia thdi dlt cd chua canh sic cua luoi dIo duoc x l c dinh theo mat elt nguy hiem tao vdi phuong thing dung mot gdc <p (gde ma sit trong eua dlt).
Vdi gia thuyet ung suit nen ciia luoi dIo len mat dly cua thdi dat phan bd theo quy luat bac nhlt, khi dd luc nen tdng hgp theo phuong BC duge xlc dinh theo e6ng thire sau:
Z cr„ = 10"- So-,,,,,,.! sin ycos(p; (5) Trong dd: CT,,, irng suit tdi ban eua dat khi hi nIn dirt, kG/cn/; S - budc elt eua luoi dIo (dp cung Khi dinh luoi dIo chuyen dong tir diem C phuong d p ) ,m;(p - gdc ma s i t trong eua dlt (° j .
chuyin ddng eiia thdi dlt tren mat luoi dIo ngugc ehilu vdi ehilu tiln eua mIy, do Idp dlt tren luoi dIo tuong ddi mdng khi dd Ip luc nen khdi dlt tren luoi dIo du ldn llm cho thdi dlt hi elt rdi khdi mat ddng, trd nen tu do tren luoi dIo va b i t diu trugt ra phia ngoli. Duoi tic dung cua luc trgng trudng, luc ly tam, luc ma sit lam cho khdi dlt bit diu din trugt ra ngoli theo mat phIng nghieng ciia luoi dIo v l phia tmdc vl nhd vIo dong nang dugc tich luy thdi dat duge tung sang hai ben tao nen ranh dIo.
Hinh dang cua thdi dat tren luoi dao phu thupc vIo tinh chit, trang thii cua dlt v l d c th6ng sd cua
Luc d n e l t tdng hgp sinh ra tren elc mat bin ciia thdi dat chdng lai q u i trinh nIn, elt dugc xac dinh theo c6ng thue sau:
Z r = 1 0 - 25;^ +• Z,sin;K coscp (6) T = C + ajgip;
Trong dd: h^- khoang d c h tir mat ddng din dinh luoi dIo; r - ung suit tilp tren mat dlt hi elt rdi, kG / cm-; C - he sd dinh cua dlt, kG I cm'. Do d d c
mat cat ben ung suit nIn a^, tuong ddi be vi vay cd thi bd qua, khi do ta co:
Z r =10^
1^ cosip Lsiny C (7) Dua vao phan tich tren cho phep xac dinh dien tich mat elt ngang ldn nhlt eua thdi dlt tren luoi dIo khi bit diu tung dugc xac dinh g i n diing theo dilu kien Xcr,, = Z r^ , tir (5) vl (7) ta ed:
l(r"5'cr„„Xsin;HXis'^=10"" 2Sh..
costp
hay h^^ S(^„,a,Bs\nycos-(p C {iScoscp -^ Ls,\ny)
C (8)
(9) Cle gil tri dac trung C7„,^^^ vl C trong c6ng thuc (8) dupe xlc dinh tren ca sd dua vIo dac dilm co ly tinh cua timg loai dlt, gil tri tmng binh ddi vdi dlt trdng mia d miln Tmng Viet Nam cd cr^^^^^^ = 1 2 - 2 2
kG /cm-;C = 0,2 - 0,7 k G / e m l
Dien tich mat elt ngang ciia thdi dlt ldn nhlt nlm tren mat luoi dIo F^. duge xlc dinh gin diing nhu dien tich cua tir gilc ABCE. F^ II dien dch g i n dung cua hinh binh h i n h ABCD v l F^ II dien tich gin diing hinh tam gilc CDE.
Dp dii cua canh CD (/) dugc x l c dinh theo cong thuc:
/ Z i s i n ( ^ - ^ ) s i n ^ Gdc 0 dupe xlc
d-y-ar sin
dinh R
(10)
theo e6ng thue:
(11) J
Trong dd: R - bin kinh phay dIo, m; h^- ehilu dly lop dat dly ranh, m.
Gdc dat luoi dIo cd Inh hudng d i n gde elf dat, do dac tinh cua d c may dIo ranh trdng cay trong nong nghiep II vira phii d i m bio elt dat tdt d l lam nhd dlt, mat khIc lai phai dam bao nang suit tung dlt nhlm nang eao hieu qua sir dung mIy. Theo nguyen ly lam viec n l u mudn phay dao elt dlt tdt thi gdc dat luoi dIo phii chgn gil tri d n g Ion d n g tdt, ngugc lai mudn tang nang suit tung thi chiing ta d n chpn gdc dat cua luoi dIo b l . Viec xac dinh goc dat cua luoi dIo dugc xlc dinh thong qua thuc nghiem dl phii hpp vdi mdi loai dlt va d c yeu clu n6ng hpc
khIc. Kinh nghiem nghien cim ciia ban than tic gia cho thIy, gdc dat ddi voi luoi dIo trong cac mIy dIo ranh trdng cay nong nghiep nen chpn / = 45 - 55" II thich hpp.
Dien tich mat elt ngang eiia thdi dlt khi bit diu tung dupe xlc dinh nhu sau:
h^^bs\n[(p-6) b'sm{^(p-6)s,m0 F^.-F,+F,
hay
s i n ^ 2 s i n ^
^ b(2h+bsm0)sm((p-0) K = ^ " ^^.^ ^ ^ (12)
60 sin ^
Nang suit elt vl tung dat eua phay dIo x l c dinh theo c6ng thuc (2) cdn phu thupc vIo dilu kien d l ed t h i llm dly luoi dIo. Vi vay, nang suit cat v l tung dlt thuc t l eua phay dIo duge x l c dinh theo c6ng thuc:
r^ _,^^_K,^^^yb{'^^.+bsm0)sm[(p-0)
Vii -\Ui TTT;-. ,mVs;(13) 360sm^
Trong dd: k^ - he sd k h i nang llm dly ciia phay dIo; h - he rpng luoi dIo, mm.
2. He sd sir dung nang suat tung cue dai cua phay dao
De dinh gia kha nang tung d l t ciia phay dIo xin d l xult he sd dupe xay dung tren ea sd x l c dinh mdi quan he giira nang suit elt vl tung Q2 v l nang suit llm viec ciia phay dIo Qj. Khi goc 0 he k h i nang tung dlt ciia phay dao tang len vl ngugc lai khi de tang kha nang cat thi goc 0 chgn nen ldn. De nang eao hieu q u i eiia bg phan dao eIn bd tri them bp phan llm viec hi ddng phia tmdc nhlm p h i va dat gilm bdt chi phi nang lupng elt dat eua phay dIo, khi dd luoi dIo dupe thief k l v l lap dat sao cho gdc 0 tdi thieu, vi vay c6ng thirc (13) ed the x l c dinh g i n dung nhu sau:
a,=/t,0,=^^^^*>l^,m3/s.
180 (14)
Thue t l khi mIy llm viec luon lu6n tdn tai viec roi trd lai ranh mot lugng dlt, tuy yeu clu n6ng hgc dly ranh dao m l d n lugng dlt day hay mdng. Nang suit tung mIy thue t l phii thue hien bao gid cung ldn hon nang suit tinh toan ly thuylt mot gia tri nhlt dinh, ty sd giua hai gil tri nang suit tren duge tic gia dat ten II he sd su dung nang suit hing cue dai ciia phay dIo {he sd dac trung khi nang tung dat cua phay dao) va duge xac dinh nhu sau:
NONG NGHIEP VA PHAT TRIEN NONG THON - SO 4 - THANG 4/2010 43
t. = a
kjZLnbSa^x)sjpsuyy_(15)
" Q lS0C{2Scos(p + Lsiny)V,„Hk,/
Tir phuang hinh (15) cho thay, k h i nang timg dlt ciia phay dIo ngoai sy phu thupc vIo sd luoi dao (4, b l rpng llm viec cua luoi dIo {b), tdc dd quay cua phay dIo {n), van tdc llm viec ciia mIy (T^)... da dupe nghien cim hinh bIy ti-ong tii lieu [4], ngoli ra cdn phu thupc nhilu vIo chilu dii canh (Z) cua luoi dIo v l dd sau cua ranh dIo {H) dd II hai thong sd co bin lien quan din kich thuoc cua ranh dIo. He sd dac trung kha nang tung dlt ciia phay dao la ham cua nhieu thong sd:
k^^ = f{Z,b,n,L,y,V,„,H,Cvak,) (16) Dua vIo yeu clu ky diuat n6ng hgc ciia ranh dIo
trdng cay c6ng nghiep (mia, sin...) hoac la ranh tudi tieu, cho phep ta xlc dinh he sd k^^ thich hgp, dua vIo cle mdi quan he giua k^^ va cle fh6ng sd hinh hgc vl dong hpc ciia may dao phii hpp d l cd the tao dupe ranh dao dat cle yeu clu nong hgc d l ra.
3. Anh hudng cua mot sd th6ng sd den kha nang tung dat cua phay dao
a) Anh hudng chieu dii cit dat (L ) cua ludi dao va he sd lim diy ludi dio (k,) den he sd dac trung kha nang tung dit cua phay dio k^^ ciia phay dio
(hinh 4)
•^
1 0 0 1 5 0 2 0 0
L(mm)
Hinh 4. Su phu thugc eiia k vao L va y Cic th6ng sd eua d l t v l ranh cho tmdc: k^ = 1,3; C = 0,6 kG/cnf; (p= 45°;
cr„„„=22 kG/cnr; 7=60"; / / = 4 0 0 m m . Cle th6ng sd llm viec cua mly.'Z = 10; b
= 90 mm; n = 400 v/p; D = 1000 mm; J^„
= 0,7 m/s; 5 = 80 mm; k^ = 0,9
Khao sit Inh hudng ciia L den k tuong iing vdi gdc tung dat thay ddi ;K = 40 - 60°.
Qua dd thi hinh 4 cho thay, ehilu dii d n h eua luoi dao quan he voi he sd nang suit tung dat cua phay dao theo mot duong cong gin bac 2. Ung vdi gdc tiing dlt la 60" khi chilu dai luoi dao tang tir 50 - 150 mm (3 lln) thi he sd nang suit tung tang cham hon so voi muc do tang chilu dii luoi dio (2 lln).
Nhu vay, d gde tung d l t cang ldn vdi chilu dii luoi dio tang thi k h i nang tung dat cua phay dio cung tang len, qua day ta nen chgn chilu dai luoi dao khoing 50 - 150 mm II phii hgp. Tuy nhien, chilu dii cua luoi dio phu thugc vao b l rong ciia ranh cin dio, n l u ranh be ehi d i o mdt lln se dugc ranh dao cd kich thudc yeu clu, ddi vdi ranh dao ed kich thude ldn hon 2 lln chieu dii luoi dao thi d n dio nhilu lln.
Dd thi cho thIy dii ed tang chilu dii luoi dio thi kha nang tung d l t cilng chi tang din gidi ban img vdi kj
< 0,45. Vi vay de tang kha nang tung d l t cua phay dio cin tang sd vdng quay, sd luoi dio eiia phay dao de tang kj g i n cd g i l tri b i n g 1, khi dd dlt dupe elt se dugc tung ra khdi ranh mdt lln. Kit qua nghien cuu tren cho thay, ddi vdi mIy dio ranh trong n6ng nghiep de tang nang suit llm viec vl dat yeu clu n6ng hgc nhlt thilt phii lip tam vet cd k h i nang dilu chinh kich thuoc phia sau phay dio nhlm tang k h i nang llm d l y cua luoi dio v l chit lugng ranh.
b) Anh hudng cua dp sau ranh dio (H) vi kj den den he sd dac trung khi nang tung dat ciia phay dao k, (hinh 5)
0.8
0.6
0.4 -
0.2
200 300 400 500
H(mm)
Hinh 5. Sy phu thugc cua ^„ vao H va k^, Cic thong sd ciia dlt cho trudc: k,.^ = 1,3; C"= 0,6 kG/cnf; tp = 45"; (T,„,„ = 22 kG/cnr'. Voi cac thOng sd llm viec ciia mIy: Z = 10; Z? = 9 0 mm, n = 400
v/p D = 1000 mm; V,„ = 0,7 m/s, S = 80 mm, y = 60"; L = 150 mm. Khao sit anh hudng cua H d i n k
tuong img voi kha nang lam dly eua luoi dao voi cae he sd lam dly tuang ung: ^ , = 0,9, 0,8, 0,7.
D6 thi hinh 5 cho thIy, ung voi kha nang llm dly gil dinh k^i = 0,9 va khi lam viec d do sau thay ddi tang hi 300 - 500 mm (tang 1,66 lln) thi he sd nang suit hing ciia phay dio lai giam tir 0,55 - 0,35 (gilm 1,57 lln). Nhu vay khi do sau cua ranh dio tang len, mudn tang khi nang tung dlt ddng nghia vdi tang hieu qui dao cua mIy ung vdi dudng kinh phay dio D = 1000 mm chi nen chpn dp sau ranh dio khoang 400 mm. Voi ranh cd dd sau ldn de tang hieu qua elt va tung dlt ciia phay dio ngoli luoi dao lam nhiem vu elt dlt va tung dat cin bd tri them luoi hit dlt de tang nang suit tung dlt, giam lugng dlt roi trd lai ranh dio vugt qua yeu clu nong hpc d l ra, trudng hpp cin thilt cin giam van tdc chuyin dong eua may dio hoac tang van tdc quay cua phay dio.
IV.KETLUAni
Da xay dyng dupe m6 hinh toan hgc m6 fa mdi quan he giQa elc ylu td hinh hgc, dong hpc va dac dilm CO ly tinh cua dlt v l chuyen dong eua thdi dlt tren luoi dio trong q u i trinh llm viec cua mIy, gop phan xlc dinh k h i nang tung dlt cua mIy dio dang phay. Tren co sd nghien cuu x l c dinh nang suit llm viec va nang s u i t elt, tung d l t eua phay d i o , lya chpn cac th6ng sd d u tao v l d l xult th6ng sd dong hpc cho viec thilt k l e h l tao mIy d i o d i p iing yeu
clu n6ng hpc. Da xac dinh dupe cac th6ng sd thilt kl, bio dim k h i nang dao, tung dat hieu qui, dd la: Ung vdi gdc tung dlt thay ddi y = 40" -^ 60°, chilu dii luoi dio L tir 50 + 150 mm va dd sau ranh dio H = 400 mm.
Tuy nhien, d l tang nang suit llm viec va dat yeu clu n6ng hpc, nhlt tiiilt phii lip them tam vet cd kha nang dilu chinh kich thudc phia sau phay dio. Ngoli ra, cung vdi luoi dio llm nhiem vu elt va tung dlt d n bd h-i them luoi hit de tang nang suit tung dat.
TAI UEU THAM K H A O
1. Chen Jun, 1997. Study on the soil throwdng property of the rotary blades with high speed photography. Transations of the Chines Society of Agricultural machinery, Vol 28.
2. T Kataok et a l , 1995. A model for back ward throwing of sliced soil clods by a revere - rotational rotary tiller using rigid body kinetics. Pro. of the 4 th ASIA - PACIFIC Regional cof. of the ISTVS Japan, pp. 339-346.
3. Nguyin Van Phlt vl ddng tac gia (1999). Ca sd xlc dinh nang suit tung dat ciia bp phan llm viec quay chu dong ti-ong mIy dio ranh ti-dng mia. Tap chi N6ng nghiep C6ng nghiep Thyc pham, ti" 143 -144.
4. Nguyin Van Phat (2007). Anh hudng eiia mot sd th6ng sd llm viec cua mIy dio kieu quay nghich vl kha nang img dung trong san xult n6ng nghiep. Tap chi Nong nghiep vl Phlt hien nong thon, tr 12 - 1 5 .
THE THEORETICAL MODEL FOR THE RESEARCH ON THE INFLUENCE OF THE LENGTH OF DIGGING BLADE AND THE DEPTH OF ITS SLOTS ON THE ABILITY TO TURN OVER THE SOIL OF
THE INVERTING PART OF THE FURROW DIGGER IN FARMING
Nguyen Van Phat Summary
The paper deals with the results of the research study on calculated model based on the relationships between geometry and dynamic parameters of the furrow digger, of dug furrows (width and depth) and other mechanical typical parameters of soil. The focus of the paper is on the relationships between the length of the digging blade, the depth of the furrow and the capacity in soil over-turning in order to submit the scope for selecting the parameters and completing the digger structure to ensure the quality of the dug furrows, to improve operating productivy of the machine. The results confirmed the designed parameters to make sure the digging capacity and the effective soil over-turning capacity. That is: correspondingly if the over-turning angle changes the length (L) wiUbefrom 50-150 mm and the depth of the furrow will be H=
400 mm. However, for increasing the working productivity and meeting the agronomy demands, it is neccessary to fix together clearing panel enabling to adjust the size after the digging plate. Besides together with the digging blade while cutting and turning over the soil, it also needs fixing a throwing blade to increase the over-tuming capacity.
Key words." Furro w digger, soil o ver-tiiming productivity.
Ngudi phan bien: GS. TSKH. Pham Van Lang
NONG NGHIEP VA PHAT TRIEN NONG THON - SO 4 - THANG 4/2010 45
