Tir nguyen ly lam viec, de xac dinh dugc cac thong so hinh hoc va luc tac dung len he thdng boc gd, can phai giai quyet bai bai toan: Nang dau bo gd len do cao cin thiet va keo bo gd tir
Trang 1KHOA HQC CONG N G H l
c a S Q XAC DIIMH CAC THOIMG SO HllMH HOC V A LUC TAC DLJIMG LEIM HE THOIMG DOC G d IMHO CHO R O IVIOOC LAIVI IMGHIEP D A T S A U IVIAY K E O IMOIMG IMGHIEP D E
VAlM X U A T G d RUIMG TROIMG
Nguyin Van Quan'
T O M T A T
Bai viet trinh bay torn tit co so ly thuyet xac dinh cac thong sd hinh hoc va luc tac dung len he thdng boc
gd nho bang toi cap vai su trg giup cua co cau nang gd thuy luc - mot phuong an boc gd nho kieu moi cho
ra mooc lam nghiep dat sau may keo nong nghiep de van xuat gd rimg trdng Tir nguyen ly lam viec, de xac dinh dugc cac thong so hinh hoc va luc tac dung len he thdng boc gd, can phai giai quyet bai bai toan: Nang dau bo gd len do cao cin thiet va keo bo gd tir true con lan vao san ra mooc Tren co sd' phan tich cac luc tac dpng len he thdng keo gd, van dung cac phuang phap cua ca hpc giai tich thiet lap dugc cac phuang trinb dong hoc va he phuong trinh vi phan mo ta qua trinh keo go tir true con lan vao san mooc Giai he phuang trinh nay theo phuang phap Runghe - Kutta voi su trg giiip cua may vi tinh, tir do xay dung cac dd thi bieu diin su phu thuoc cua cac dai lugng nghien ciiu vao cac tham sd anh huang Khao sat dpng hpc va dpng b e hpc qua trinh nang dau gd tir mat dat len dp cao can thiet de keo gd vao san mooc, xac djnh dugc cac thong sd dpng hpc va lire tac dung len xi lanh thuy luc cua ca cau nang Tren co sa kit qua giai hai bai toan da dua ra trinh tu va phuong phap xac dinh cac thong sd chii yeu cua he thdng boc go
Tir khoa: Dgng Itfc hgc mdy keo, ra mode mgt trtic, nghien curu thttc nghiem
LDATVANDE
CIc miy k l o n6ng nghiep (MKNN) thudng Ilm
viec theo thdi vu, khdi lugng cong viec trong nam
phan bd khong diu, do vay, d l nang cao hieu q u i
vdn dau tu, phlf huy tdi da nang lire cua miy mdc
thilt bi cd fhl sii dung MKNN de van xult gd b i n g
d c h trang hi them cho miy d c thilt bi phfi hgp nhu
tdi, ro mode, co d u hoc gd Tuy nhien mdi loai m i y
chi b m viec cd hieu qua trong nhung diiu kien nhlt
dinh dugc xle lap tii khi fhilf ke, c h i tao Do dd de
cd the khai thic MKNN cd hieu q u i d' nhung diiu
kien sii dung mdi d n fhilf phii nghien cuu cu fhl d
v l ly thuylt v l thuc nghiem de thilt k l hoac lira chgn
cle thilt hi thich hgp kem theo cung nhu cle e h i do
su dung Bii vilt trinh bly tdm b t co sd' ly thuyet xle
dinh d c thong sd hinh hge v l luc b e dung len he
thdng hoc g6 nhd theo phuong phip boc dgc b i n g
tdi d p vdi su trg giiip cua eo clu nang gd thuy b e
-mgt phuong In hoc gd nhd kieu mdi cho ro mode
b m nghiep mgt true dat sau MKNN de van xuat gd
rung trong
: - r ; w ¥ * •••"":^
' TS Khoa Co dien vl C6ng trinh - Trudng Dai hgc
Lam nghiep
Hmh 1 May k l o n6ng nghiep dugc frang hi ro mooc
va CO d u hoc g6 de van xuat g6 nhd rimg frdng
1 Nguyen ly lam viec cua h e thdng hdc g6 Ddi vdi viec bde gd nhd theo phuong phap bde dgc b i n g tdi d p thudng gap 6' chd: Do kich thudc
cay gb nhd, d l bde du trgng b i mgt chuyin xe phai
hoc rit nhiiu lln, do vay n l u k i t d u cua he thdng hoc gd khong hgp ly, se din tdi tinh trang d c bd gd hoc sau se bi thfic diu vio ldp go da dugc hoc len trudc tren sin mode, vi t h i khong fhl boc x i p gd len cao dugc D l trinh hien tugng nly trorg sudt qua trinh tdi keo gd, diu bd gd d n dugc nang b n mgt do cao thich hgp De giii quyit van de nly da dung co
d u nang gd din dgng bing thuy luc dat phia cudi ra mode Co clu nly gdm bai ddn nang ndi voi khung
Trang 2KHOA HOC CONG NGHE
mode b i n g khop quay, diu mut cua hai don nang
dugc ndi vdi nhau b i n g true con lan Hai don nang
cung true con b n dugc nang len, ha xudng nho hai xi
lanh thuy luc b m viec ddng thoi dat d phia sau
khung mode (hinh 1)
Qua trinh hoc gb len san mode dugc filn h i n h
theo frinh tu sau: Ha true con lan cua ca cau nang
nlm sit mat dat; diiu khiln tdi keo gd, khi mot dau
bd g6 glc len true con lan lap tiic ngif truyin dgng
din tdi; diiu khiln he thdng thuy luc nang true con
lan cfing mgt dau bd gd len do cao thich hgp; diiu
khiln tdi tilp tuc keo gd tir true con lan vao vi tri
mong mudn tren sin mode Viec hoc chuyin tilp
theo, cle thao tie dugc lap lai theo frinh tu tren
Tfr nguyen ly bde go neu fren dat ra bii toln nhu
sau: Gil sir vdi mgt ro mode cd kich thuoc v l trgng
bi da chgn, d n phii xic dinh d c th6ng sd hinh hge
cua he thdng bde g6 de cd the keo dugc go len ldp
tren ciing eua mode vdi chilu cao bde da dinh (Hi)
Ngoli ra, d n xle dinh lire ldn nhlt b e dung len d c
pbin tfr eua co' eau nang vl co d u keo go de b m eo
sd tinh toan sue ben cho d c chi fief cQng nhu xle
dmh b i trong ldn nhat m l LHM ed the keo vl nang
dugc Vi d c thong sd tren lien quan chat che vdi
nhau, do vay d l cd co so lira ebon vl xle dinh d c
tb6ng sd nly mgt d c h hgp ly d n phai khao sit mgt
cich tdng fhl d c mdi quan he giiia chiing vdi nhau
II niOl DUniG, PHUONG PHAP NGHIEN CUU
Khao sat qua trinh k l o g6 tfr true eon lan vao san
mode
Giai doan l:.Tu khi tdi bit diu k l o d i n khi foln
bo cay gd dugc nhac len khdi mat dat, trong giai
doan nly cay gd hi k l o lit tren mat dit tai diem A
Giai doan 2: Tu khi k i t fhuc giai doan 1 den khi
dau cay g6 g l c vio sin mode hoac ddng go da cd
tren mode, 6 giai doan nly cay go dugc keo trugt tren
true con lan ciia eo d u nang De keo dugc bd go len
ldp tren cfing vdi chilu eao x i p g6 Hi cho truoc fhi
diu bd go khi a vi tri eao nhlt phii eao hon hoac phii
ngang bing ddng go da xip tren mode n l u khong se
thuc vio ddng gd tren mode (hinh 2)
Hmh 2 So dd khao sit qua tiinh k l o gd tii true con lan vio dau s i n mode
Xem bd go nhu mot cay go co chilu dai L, trgng tam C, khdi lugng m, mo men quan tinh ddi vdi trgng fam J Chon he true toa do XOY khIo sit chuyin dpng cua cay gd, he true nly ed gdc 0 friing vdi true
con lan do' cay go a vi tri cao nhat, OX song song vdi
mat dit, OY vuong gdc vdi mat dit Vi tri ciia cay gd trong he true toa do XOY duge xle dinh bdi trpng
b m C (xc ,yc ) • Ggi (cp) 11 gdc quay cua cay gd so vdi tnrc OX
Luc b e dung len cay gd gom: Luc keo cua day
d p tdi F ; frgng lue G; phin luc Ng v l luc ma sit F^^
do true con b n b e dung b i diem O; phan luc N^vl luc ma sit F J do mat dat tic dung tai diem A
Tfr so do (hinh 1) ta vilt dugc he phuong trinh:
\gcp = ^
Xg = x^ - L^coscp
yg = y,- -L^sincp ( l )
X^ = X^ -I- L|C0S99
YA =yc+LiSin99
S" = (Xf - LjCosK - Xg)^ -I- (y^ - L^sin^j - y^)^
Trong dd, S - khoang d c h giua diem B (diim bugc g6) vl diem E (diim treo puly tdi)
Phuang trinh dgng luc hgc Giai doqn 1 - keo lit tren mat ddt: Lap phuong
trinh vi phan ehuyen dgng eua cay gd dudi b e dung ciia he luc tren, ta dugc he phuong trinh sau:
FQIYE -YB) + H 0C6CP + N , + H ^ , sincp = ni/c + ng
I;|(XE- J I Y E - YB) - (YE - Y B K - X B ) ] - H(ycsincp+Xc0oscp) + ^[x^-\ + f^Yc-YA
Trong he phuong frinh 2: fo, f,, - he sd cin giira true con lan va mat dat voi cay gd
(2)
= Jcp
Trang 3KHOA HOC CONG N G H l
Tir he phuong trinh (1) lap dugc d c phuong trinh sau:
y P = - (p Ll cosf (3); X, = ( — ^
sin" cp
- S S
+ L, sin cp)cp
(p =
sin" cp
-i-(L, -i-L2)4'sir'(p
tgcp -F(L| -)-L2)coscp-i-Xg + (L| -i-U)cos(f[h-i-(L| -i-L,).smcp-i-yEj
(4)
(5)
Phuong frinh (5) dugc giai vdi diiu kien diu:
diem B friing vdi diem 0 , khi dd ta cd:
+ yi
eua d p tdi; f
arctg
arctg
VQ ; Vfl - van tdc keo
Y c _
V(L, + L , ) ^ -h'
Dieu kien d l k i t thuc giai doan 1 b diu A ciia cay gd dugc nhlc khdi mat dit, khi do N,, = 0 CIc luc N,i, Fo, N„ dugc xac dmh tfr h e phuong frinh (2) Cac gil fri yc, Xc , f cung nhu y ^ X ^ , cp dugc xic
dinh nhd phuong trinh vi phan (3), (4), (5); y ^, \^,
cp xac dinh nhd' tich phan sd
Giai doqn 2 - cdy gd dug'c nhde khdi mat ddt: 0 giai doan n l y N^= 0, he phuong trinh dgng luc hoc
cua cay go ed dang:
FQIXE - X B ] - No sincp -HNQ^ ooscp = niic
FO(YE - Y B ) + NQ ooscp -h -f- N^^ sincp = n f c + n g
( X E - XB)(YE - YB) - (YE - YB)(XC-XB) - No(ycSincp+XcOOS(p)
B,= 2
(6)
Jcp
Day 11 he 3 phuong trinh vi phan vdi 5 an sd, d n
lap them 2 phuong trinh:
All X ^ + A , 2 y ^ + A i 3 9 =Bi (7)
Trong do : All = (xc L2 cosf xg ) ; A ^ = ( yc
-L2sinf - ye ); A13 = AnL^sinf - A12L2 cosf ; - B] =
cp^L2Cosf (xc-L2Cosf -XE)-I- (X^ -^ (pL2sinf)'
icp^L2Cosf (ycL2sinf yE)i (Yc (plvjcosf ) '
-Vo^; A21X +A22 Vc +A23 qp = B (8)
x^cp ^ x^cp-tgcp
Trong dd: A21 = - tgf ; A22 = 1; A23 = - X ,
COS' cp
cos cp cos cp Kit hgp (6); (7); (8) dugc he 5 phuong trinh vdi
5 an la X^ ; y^;Cp ; NQ; FQ Cd fhl giai dugc he phuong frinh tren theo phuong phip Runghe - kutia vdi su trg giiip cua m i y vi tinh
III KET QUA VA THAO LUAN
1 Qua trinh k l o g6 tu true eon lan vio san mode
F,No,Nd (N)
6000 T
XB(m
Xc(m)
r*-, —^ oc
Hinh 3 Quy dao chuyen dong ciia dau cay g6
trong qua trinh keo go tii' true con lan vao san
mooc
0
0
OJ
• ^
0
^O
0
ly-,
0
X
0
CM
—
Hinh 3 - Su phu thuoc ciia cac luc vao
trong tam cay gd
Trang 4KHOA HOC C b N G NGHE
a Quy dqo chuyen ddng cua ddu cdy go (diem B)
tie true con ldn vdo t&i ddu sdn mdc YB = f(xB) vdi d c
tham sd khac nhau d i u ed dang tuong tu nhu hinh 2
b Su phu thudc cua lite keo cdp t&i (F), phdn luc
cua true con ldn tin cdy gd (Ng), phdn luc cua mat ddt
len cdy gd (NJ vdo toq do trgng tdm cdy go (XQ) cd
dang dd thi nhu hinh 3
Ttr quy dao hinh 2 cho thay: Khi k l o gd tfr true
con lan vio san mode diu cay gd dugc nang din len
din vi fri cao nhat (yB= yBm.ix) sau dd di xudng: Chilu
cao diu cay gd giam din b e dau vdi tdc do cham sau
dd giim rat nhanh- dd chinh 11 giai doan cay g6 hi lao
xudng Tai thdi diim dau cay g6 d vi fri eao nhat n l u
khong dugc ty vio ddng g6 da cd tren mode hoac
khung mode hay ndi d c h k h i c khong cd vat gi do' nd
va nlu tilp tuc dfing tdi k l o thi diu cay gd se bi chui
xudng rdi thiic vio ddng g6 hoac lao xudng dit, do
vay kh6ng fhl k l o cay gd len mode dugc Ddi vdi r a
mode chd g6, khiic gd dugc xep thd ra ngoli khung
mode mpt khoang nIo dd, diem da dau cay gd chmh
11 duoi ddng gd da cd fren mode
Goi holnh do diim B (dau cay gd) khi yB= ysmax
11 Xgo , nlu khoing d c h tii true con lan d i n du6i
ddng gd ldn hem Xgo thi se xly ra hien tugng diu cay
gd bi thiic vio ddng gd Ngugc lai, n l u khoang d c h
tfr true con lan d i n ddng gd nhd hon Xgo, diu cay gd
se dugc ty vio ddng gd, khi dd cd fhl tilp tuc keo
cay gd len mode mdt d c h de ding Nhu vay Xgo
chinh 11 khoang d c h da dau cay gd ldn nhlt cho
phip de frinh hien tugng diu cay gb hi thuc vio
ddng gd hoac lao xudng dat Tu quy dao chuyin
dpng cua diu cay gd, cho p h i p xic dinh dugc 2
thong sd: Khoang d c h tii true eon lan tdi ddng gd
ldn nhat cho phip (XBQ); chilu cao x i p gd ldn nhlt
(thong qua Yemax) ma he thdng ed fhl thuc hien
dugc
Dd thi hinh 3 m6 b su thay doi ciia d e lue b e
dung len cay g6 frong q u i frinh k l o g6 v l cho bilf
thdi diem v l gia fri d e lire fren dat cue dai
c De Ilm CO sd lua chpn va xic d b h cic thong sd hmh hpc ciia he thdng bde gd, tinh toan sue ben cac chi tilt cua he thdng bde gd; tinh toan tieu hao cong suit, chi phi nhien lieu khi LHM tu bde gd da tien hanh:
- Khao sit anh hudng cua d c tham sd: Chilu cao
frue con lan (h), vi fri treo puly tdi (xg, y^) den chieu
cao bde go (Ygmax) v l khoang each da dau gd (Xgo);
- KhIo sit Inh hudng cua cic tham sd h, x^, y^,
m den luc keo d p tdi ldn nhlt (Fn^^x) vl ap b e Ion nhlt cua cay gd xudng true con lan (Nomax) •
2 Xle dinh d c kich thudc dgng hge v l luc b e
dung lln xi lanh thuy lue cua co d u nkng go
Luc b e dung len xi lanh thuy b e ciia co clu nang dugc trinh b l y d hinh 4 Lap he true toa do XOY frong dd gdc O frfing vdi khdp quay O3; frue
OX song song vdi mat dat Luc b e dung len cay gd gdm: Trpng luc G; phin luc NQ va luc ma sat F^^do frue con b n tic dung tai diim O; phan luc Npvl luc
ma sat F^ do mat dat b e dung fai diim A
Hinh 4 Sa dd x^c dinh d e kich thudc d6ng hgc
v l luc tic dung b n xi lanh thuy luc
ciia ca d u ning gh
- Ttr so dd hinh 4, dua vio d c quan he hinh hoc
xle dinh dugc c6ng thfrc bilu thi mdi quan he giffa
d c thong sd dong hoe cua ea cau nang:
Gi+la) = 7'o+>3-21„l3Cos(p3 (9) Hinh trinh cua pit t6ng se 11:
S = O l + U ^ a x - ai+l2)n,in (10)
- Xit can bang luc eho ca d u xle dinh dugc luc
b e dung len xi lanh thuy luc:
^ L,l , fb-i-lsincp
, r- • - I, I b-i-lsin(p^ b-)-lsin(p _
7 (coscp-i-foSincp;., 1 - -i- ^(IQCOSCP-sincp)
Iglj sin((p-I-Y -I-a) (11) V'o + l3+21ol3COs((p + Y + a )
Trong cong thuc (9), (10), (11):
Trang 5KHOA HQC CONG N G H l
P luc tic dung len xi lanh thuy luc, (N); S
-hinh trinh pit tong, (m); m - khdi lugng cay go (kg);
L - chieu dii cay go, (m); t,- he sd d n gitra cay gd vl
true con lan; L, - khoang each tu dau cay go fy vio
dit den frong tam (m); 1 - chieu dai thanh nang
(0;jD), (m); ly chieu dii gil cua co clu nang, (m); l,
-chieu dii dong hoc cua khau 3 (O3F) (m); b - khoing
each tfr khdp quay thanh nang den mat dat, (m); y
-gdc hinh dang thanh nang, (") ; cp - -gdc quay ctia
thanh nang, (") ; a - gdc hgp bdi dudng ndi O1O3 vl
phuong nam ngang, (") ; g - gia tdc trong truong,
( m / s ^ ; ^'- hinh frinh (gdc lie) eua thanh nang, (")
De phan tich mdi quan he giua lire tac dung len
xi lanh thuy b e vl cac ylu td Inh hirdng ciing nhu mdi quan he giira cac th6ng sd dgng hgc cua eo cau nang, bai toan dugc giii tren may vi tinh Tir ket qua nhan dirge cho thay:
Hanh trinh pit tong (S) chu ylu phu thudc vao (I3) vl (W) - dd fhi hinh 5; Inh hudng cua lo den S la khong dang ke;
Luc tie dung len xi lanh thuy luc ldn nhlt (P„„)
chu yeu phu thugc vio khdi lugng cay gd (m) va ehilu dai l, - dd fhi hinh 6, cdn anh hudng cua 1„ den Pmax b khong dang k l
Pmax (KN)
120 T
m=1000kc m=900 kg ni=cS000kg m=7000kg m=6000kg
0 llllllllllllllllllllllllllllllllllllllllllllll I3 (m
d d d d d 00 d
O N —'
d
I I I I I 11 I I I I I I I I I I I I I I I I I I l3(m)
Hinh 5 Su phu thuoc ciia hanh trinh
pit tong vao chilu dai I3
Cae dd thi SO3, ^ ) vl P^^d^, m) 11 co sd' d l chgn
xi lanh thuy b e din dgng cho co clu vl xle dinh cle
thong sd dgng hgc ciia co d u nang gd
3 Trinh tu v l phuang phip xae dmh d c thdng
sd hmh hgc v l luc b e dung len he thdng bde gd
Tfr d c kit qua nghien cuu 6' mue 1 vl 2 da dua
ra trinh tu vl phuong phip xae dinh eac th6ng sd
hinh hge ehu ylu v l luc b e dung len d e pliln tii cua
he thdng bde gd phuc vu cho viec tinh foln thiet k l
gdm 10 buoc:
1 Xac dinh chilu cao xep gd (H,);
2 Chgn chieu cao true con b n (b) vl holnh do
puly tdi (XE) tuc 11 chgn truoc vi fri cao nhat cua true
eon lan;
3 Xac dmh ehilu cao diu bd gd ldn nbat tren
quy dao chuyen dgng cua nd (yB,„,J d n thiet de co
fhl keo dugc bd gd len do cao H,;
4 Xle dmh chilu cao puly tdi (H);
5 Xle dinh khoing each do diu gd ldn nhat cho
phep (XBO);
d -: ^
30
01
d
d
Hinh 6 Su phu thuoc ciia luc tac dung len
xi lanh thuy luc Ion nhat vao chieu dai I3
6 Xle dinh lue keo ldn nhat eua d p tdi (F^^J, Ip lire len true eon b n ldn nhat (No^ax); 7 Xle dinh gdc
quay d n thilt ciia thanh nang (W);
8 Chgn ehilu dii gil eo d u nang (lo) vl chilu dii dgng hgc cua thanh nang G3);
9 Xle dmh h i n h trinh tdi thieu cua xi lanh thuy Ifrc (S„,„);
10 Xle dinh lue b e dung len xi lanh thuy b e ldn
n h a t ( P „ , J
IV KET LUAN
1 Tren eo sd' phan tich luc fac dgng len he thdng
keo gd, bii b i o da xay dung dugc he phuong trinh vi
phan mo b q u i trinh keo gd tfr true eon lan vao sin mode: Giai doan 1- tfr khi tdi bit diu k l o d i n khi toan
bg cay gd dugc nhac len khdi mat dit (he phuang trinh 2); giai doan 2 - fir khi kit thuc giai doan 1 den khi dau cay gd glc vio sin mode (he phuong trinb 6)
2 Da xay dung duge bilu thfrc toan hge xac d b h
h i n h trinh pit tong (10) vl lue tac dung len xi lanh
thuy b e cua ca cau nang gd (11)
Trang 6KHOA HOC CONG NGHE
3 Khao sat cic phuong trinh dong luc hoc, xle toan thiet ke he thdng boc gd cho ro mooc dat sau
dinh dugc quy dao chuyen dgng cua cilu cay gd, lire miy keo nong nghiep de van xuat gd rung trdng
keo e l p tdi, Inh hudng cua cac thong sd hinh hge j A | UEU THAM KHAO
den d c luc tac dimg len he thdng boc gd, anh hudng n^ r^- TT, u nnncN A,.- •• -• ^-' ^
, ,, - , • , , 4-' - (1) E)ang The Huy (1995) Mot so van cle ve co
cua cae tham so xac dinh vi tn tnic con lan den cac •-^ - , - x, , „ T ' , •- T,
,NT-, - • ,NT-, ,NT-, ,NT-, ,NT-, ' ,NT-, ; ,NT-,' - ,NT-, ,NT-, ,NT-, ,NT-, - ,NT-, hocgiai tich va CO hoc may Nxb Nong nghiep Ha Noi
thong so hmh hgc cua he thong boc go, hanh trmh c, o i
va b e b e dung len xi lanh thuy luc (2) Forsyfhe G E, Mabolm M A, Moler C B
Tfr kit qua nghien cfm bai bao da d l xult
phuong phip v l trinh tu xle dmh eac thong sd chu
yeu cua he thdng bde gd, b m co sd' cho viec tinb
(1990) Computer Methods for Mathematical Computation, Prentice Hall NC Englewood Cliffs Nj
07632
BASE TO DETERMINE GEOMETRICAL P/\RAMETERS AND FORCES EFFECTING ON
SM/^L LOG LO/\DING SYSTEM FOR FORESTTRAILER CONNECTED WITH AN
AGRICULTURAL TRACTOR TO EXTRACT LOGS FROM PLANTATION
Nguyen Van Quan Summary
The paper gives a brief theoretical base to determine geometrical parameters and forces effecting on a
small loading system by winch which is supported by a lift hydraulic mechanism - a new small
log-loading method for forest trailer connected with an agricultural tractor to extract logs from plantation
From operational principle, in order to determine the geometrical parameters and forces effecting on the
loading system, it is needed to solve two problem: lift one end of the load to the necessary heigh and pull
the load from the roller shaft to the flat of the trailer Based on annalysis of the forcess effecting on the
loading system, by applying methods of analytic mechanics, kinematic and dynamic equations expressing
log pulling from the roller shaft to the flat of the trailer have been eshtablished Solve these equations by
Runghe-kutta method on computer, from that the graphs expressing the relations between studied and
affected parameters have been eshtablished The kinematic parameters and forces effecting the hydraulic
cylinder of the lift mechanism have been determined by studying kinematic and dynamic process of lifting
one end of the load from the ground to the determined heigh Based on the studied result, the proceduce
and method to determine the main parameters of the log-loading system have been presented
Keywords: Dynamics tractors, two wheel trailer, experimental studies
Ngudi phan bien: GS TSKH Pham Van Lang