Tiêu chuẩn iso 00789 2 1993 scan

INTERNATIONAL STANDARD IS0 789 2 Thi rd edi t i on 1 993 08 I 5 Agricultural tractors Test procedures Part 2 Rear three point l inkage I i fting capacity Tracteurs agricoles M&hodes d’essai Partie 2 C[.]

ST A NDA RD 789-2

Third e itio

19 9 3 -0 8 -I 5

Tra te rs agricoles - M&ho es d’es a i -

IS0 (the Interna t iona l Orga niza t ion for Sta nda r diza tion) is a worl wide

f eder ation of na t iona l stan a r ds b dies (IS0 memb r b dies) The w or k

of pr epa r in Int erna t iona l Stan ar ds is norma lly ca r r ied out t hrou h IS0

which a t ec hnic a l commite ha s b en esta bls ed ha s t he r i ht to b

r epr esented on tha t commite Int erna t iona l orga niza t ion , gov er nmenta l

a nd non-gov er nment a l, in la ison with ISO, also take p r t in the w or k IS0

c ola or ates c losely wit h the Int erna t iona l Elec tr ot ec nic a l Commis ion

(IEC) on all mater s of elec trotec hnic a l sta nda rdiza tion

Dr af Int erna t iona l Sta ndar ds ado ted by the t ec hnic a l commite s ar e

c ircula ted to t he memb r b dies for v ot in Publc a tion as a n Int erna t iona l

Sta ndar d r eq ir es a ppr ov a l by at le st 7 % of the memb r b dies c a st in

a v ote

Int erna t iona l Stan ar d IS0 7 9-2 wa s pr ep r ed by Tec hnic a l Commite

lSO/TC 2 , Tr actor s a nd ma c hinery for a gr ic ulture a nd forestry, Sub-

IS0 7 9 c on ists of the folowin p r ts, u der the gener a l t i e A gricultural

tra tors - Test proce ures:

- Part 1: Power tests for p wer tak -of

- Part 2: Rear thre -p int lnkag lfing c pa ity

- Part 3 Turning a d cleara ce diameters

- Part 6: Centre of gravity

- Part 7: A xle p wer d termin tion

- Part8: Engine air clea er

- Par t 9: Power tests for drawbar

Al rig ts r es rv ed No pa r t of this publcatio may be r epr od c d or utiz d in any form or

by an mean , ele to ic or me hanical in lu in ph toc opyin a nd microfim, w ith ut per -

mis io in writin fr om t he publs er

Inter na tio a l Or ganizatio for Sta nda r dizatio

Cas Po tale 5

l C -121 Ge eve 2 l Sw itz r lan

Pr i te in Sw itz r lan

- Part 10: Mea urement of hyraulc p wer - Tra torimplement

interfa e

- Par t 1 : Ste ring c pabity - Whe le tra tors

An e x A forms a n int egra l p r t of t his p r t of IS0 7 9

A gr icultur al tractors

This p r t of IS0 7 9 sp cif ies test pr oced r es for de-

t er minin the lft in ca pa cit y of r ear -mou ted thr ee-

p int lnka ge s stems:

a) t he maximum v ertic a l for ce which c a n b exe ed

by t he hy dra ulc lf t at the low er hit c h p ints

t hrou hout their ful r an e of mov ement

b) t he maximum v ert ic a l for ce which c a n b exe ed

by t he hy dra ulc lf t, at a p int 610 mm to the r ear

of t he hit c h p int s on a fr ame a ttac ed to t he

thr ee-p int lnka ge, t hrou hout it s ful r a nge of

mov ement

c) o t iona lly , the a bi t y of t he lf t in s stem to ma in-

t a in t he loa d in the lf t d p sit ion wit hout hy dra ulc

p w er

NOT ES

1 To en ure that the lf t in c a pa c ity a nd the hy dra ulc

p wer ar e a deq ate for ef f ectiv e pr a ctica l u e a nd a lso to

allow for v a ria t ion in t he p r for man e of nomina lly identic a l

tr ac tor s, the me s r ed ma ximum p r for man e is r ep r ted

as t ha t which would b o ta ined wit h the hy dra ulc fluid

pr es ur e ma inta ined at 9 % of t he pr es ur e s st a ined by

t he relef va lve (se 6.1.3 4)

2 A sta tic test pr ov ides a n adeq a te comp r i on b t w een

tr actor s I s ould b recog ized tha t the test res lt s ar e to

b u ed only as a me n of comp r i g tr actor s a nd not as

a way of r ecommen in the size of a n implement which c a n

b c ar r ied by t he tr acto

of t his p r t of IS0 7 9 At the time of publc a t ion, t he

edition in ic a ted w er e v a lid Al stan ar ds ar e s bject

to rev ision, a nd pa r ties to agr eements b sed on t his

p r t of IS0 7 9 ar e en our a ged to inv est iga t e the

p s ibi t y of a pply in the most r ecent edition of t he

stan a r ds in ic a t ed b low Memb r s of IEC a nd IS0

ma int a in r egister s of c urrently va lid Int erna t iona l

Stan ar ds

ories 7, 2 a d 3

IS0 73 -Z: 1979, A gricultural whe le tra tors -

hitc )

IS0 73 -3: 19 2, A gricultural whe le tra tors -

Thre -p int lnkag - Part 3: Cate ory 4

IS0 3 4 :19 2, Ind strial lq id lu ric nts - 1.5 vis-

cosity cla sific tion

For the pur poses of t his p r t of IS0 7 9, t he f olowin

def init ion a pply

ma chine havin at lea st t w o a x les, or a tr a ck-la yin

ma c hine, pa r t ic ula rly desig ed to p ul, pu h, ca r r y a nd

o er ate implements u ed for a gr ic ult ura l w or k (in-

c lu in f or estr y w or k), which may b pr ov ided wit h a

deta cha ble loa din plator m

q enc y , in r ecipr oca l min tes (min-‘) sp cif ied by

t he tr actor man f a ctur er for c ont in ou o er ation at

4 Me surement u its an toleranc s

The f olowin u it s a nd toler a nces ar e u ed in t his

p r t of IS0 7 9:

al

b)

cl

d)

e)

f )

9)

5

rot a tiona l f req enc y, in rev olut ion p r min te:

f 0,5 %

time, in secon s: f 0,2 s

distan e, in metres or mi metr es: + 0,5 %

f or ce, in newt on : f 1 %

mas , in kilogr ams: f 0,5 %

pr es ur e, in kio a scals: + 2 %

temp r atur e, in degr ees Celsiu : + 0,5 “C

The tr actor tested s a ll confor m to the sp c if ic a tion

in the test r ep r t (se annex A) a nd s a ll b u ed in

da tion for nor ma l o er a tion

5.2.1 The tr actor s a ll b ru -in pr ior to the test

5.2.2 The hy dra ulc f luid s a ll b as r ecommen ed

by the ma nufa ctur er a nd identif ied by ty pe a nd vis-

c osity in ac or dan e wit h IS0 3 4

5.2.3 The thr otle or gov ernor c ont r ol lev er s a ll b

set for ma ximum sp ed

5.2.4 A pr es ur e gau e s a ll b fited immedia tely

nex t to the ex t erna l ta ppin of the tr acto

5.3.1 At t he star t of ea ch test t he temp r atur e of t he

hy dra ulc fluid in the tank s a ll b me s r ed; it s a ll

b 6 “C + 5 “C I t his c a nnot b a c hiev ed, owin to

the pr esen e of a n oi co ler for exa mple, the tem-

p r atur e me s r ed d rin the test s a ll b stated in

t he test r ep r t

5.3.2 The ambient temp r a tur e d ri g t he test s a ll

6.1.1 General

6.1.1.1 Sec r e the u ba lla sted tr actor in a hori ont a l

p sition s c h tha t the tyr es ar e not deflected by t he

r ea ctiv e for ce of the p w er lf t

6.1.1.2 Adju t t he lnka ge, as a pr opr iate for the

tests with or wit hout the c oupled frame, to a c hieve

t y pic a l a nd r ep ata le ar r an ements as sp cif ied in

6.1.1.2.1 to 6.1.1.2.5

6.1.1.2.1 The lnka ge s a ll b adju ted in s c h a way

as to a c hieve the p w er r an e a nd lower hit c h p int

IS0 7 0-3 For those tr actor s which do not a c hieve

t he stan a r d p w er r an e, me s r e t he lft in for ce

at t he ma ximum a c hieva ble p w er r an e I t he tr actor

c a nnot a c hiev e t he sp cif ied p w er r a nge a nd lower

hit ch p int heig t , the fact s all b stated in t he test

r ep r t

6.1.1.2.2 The up er lnk s all b adju ted to the

len t h neces a r y to br i g the mast of the fr ame v er -

tic a l when the lower lnks ar e hori ont a l

6.1.1.2.3 Where more t ha n one up er or lower lnk

p int is a va ila ble on the tr acto the p int s u ed s all

b those sp cif ied by the ma nufa ctur er a nd s all b

stated in t he test r ep r t

6.1.1.2.4 Wher e ther e is more t ha n one p int at-

tac ment to c on ec t the lf t r od to t he lower lnks, the

c on ec tion p ints u ed s a ll b those sp cif ied by the

man f actur er a nd s a ll b stated in the test r ep r t

6.1.1.2.5 These init ia l adju tments, as far as p s -

ible, s a ll c a use the mast to r otate t hrou h a mini-

mum of 10” from t he v ertic a l to t he a ngle at which the

fr ame is in the up er most p sition I t his is not

p s ible, t he fact s a ll b stated in the test r ep r t

6.1.2 Lif at lower hitc p ints

6.1.2.1 App ly a n ex t erna l v er t ic a l downwa rd for ce to

a horizont a l b r c on ec tin t he hit ch p ints This

for ce, which s all b ca a le of b in me s r ed, s a ll

le in t he c ent r a l lon it udina l pla ne of the tr actor a nd

s a ll b ma inta ined v er t ic a l t hrou hout the lf t r an e

Car e s ould b taken to a v oid torsiona l comp nents

in t his for ce, which c a n afect t he a c cur a c y of me s-

ur ements

6.9.2.2 Deter mine t he lft in for ce a v a ila ble a nd the

c or resp n in pr es ur e of the hy dra ulc fluid at a

minimum of six p int s a pproxima t ely eq a lly sp ced

t hrou hout the r a nge of mov ement of the lf t, inc lu -

in one at ea ch extremit y At ea ch p int the for ce

s a ll b the ma ximum which c a n b exe ed a ga in t

a static loa d Ad it iona lly , me s r e the r a nge of

mov ement

The pr es ur e r ecor ded d rin t he test s all exc eed

t he minimum relef va lve pr es ur e setin

6.1.2.3 Cor r ect t he minimum of t he lf t in lo d to

a for ce cor r esp n in to a hy dra ulc pr es ur e eq iv-

a lent to 9 % of the minimum r elef va lve pr es ur e

setin of the hy dra ulc lf t s stem The cor r ected

value con t itutes the maximum v ert ic a l for ce which

c a n b s p or ted by the hy dra ulc lf t t hrou hout it s

ful r an e of mov ement

NOT E 3 L if t in for ce is pr es med to b direc tly pr op r -

t iona l to pr es ur e

ter i tic s to the thr ee-p int lnka ge

a)

b)

The mast heig t a nd the distanc e from t he hit c h

p ints to the c entrelne of the tr actor s a ll b a -

pr opr iate to t he lnk ge categor y of t he tr actor as

sp c if ied in IS0 7 0-1, IS0 7 0-Z or IS0 7 0-3

Where more t ha n one categor y is sp cif ied, that

c hosen for the test s a ll b at t he man f a ctur er ’

o tion

The c entr e of gra v it y s a ll b at a p int 610 mm

to t he r ear of the hit ch p ints, on a lne at ri ht

a ngles to the mast a nd pa ssin t hrou h t he mid le

of the lne joinin the lower hit c h p ints

6.1.3.2 App ly a n ex t erna l v er t ic a l dow nwa rd for ce,

frame at the centr e of gra v it y a nd ad t he weig t of

t he frame to it to o ta in t he lf t in for ce

6.1.3.3 Deter mine the lf t in loa d a v a ila ble a nd the

c or resp n in pr es ur e of the hy dra ulc f luid at a

minimum of s ix p ints a ppr oxima tely eq a lly sp ced

throu hout t he r a nge of movement of the lf t, inc lu -

in one at e c h ext r emity At ea c h p int the for ce

a ga in t a static lo d Ad it iona lly , me s r e the r an e

The pr es ur e r ecor ded d ri g the test s a ll exc eed

the minimum relef valve pr es ur e setin

6.1.3.4 Cor r ect t he minimum of the lft in loa ds to

tha t cor r esp n in to a hy dra ulc pr es ur e eq iv a lent

to 9 % of t he minimum relef va lve pr es ur e se in

of the hy dra ulc lf t s stem The cor r ected value c on-

stitutes t he ma ximum ver t ic a l for ce which c a n b

s p or ted by the hy draulc lf t t hr ou hout it s ful r an e

of movement

6.1.4 Re ort

The f olowin s a ll b r ep r ted:

a)

b)

cl

d)

e)

f

9)

h)

t he ma ximum cor r ected v ertic a l for ces at t he hit c h

p int s (se 6.1.2.3) a nd at the c entr e of gra v it y of

t he frame (se 6.1.3.4) as a f unc t ion of the lf t in

heig t s me s r ed wit h r esp ct to the hori ont a l

lower lnks for t he whole r a nge of mov ement of

t he lf t;

t he ful r an e of v ertic a l movement of the r e-

sp c tiv e p ints of a pplc a tion of the for ce (se

6.1.2.2 a nd 6.1.3.3)

t he pr es ur e in kio asc als eq iv a lent to 9 % of

t he minimum r elef va lve pr es ur e sett in of t he

hy dra ulc lf t s stem;

t he heig t in mi metr es of the lower hit c h p int

a bov e t he gr ou d in its low er most p sition a nd

wit hout lo d;

t he a ngle t hrou h which t he mast r otates ov er the

ful r an e of lf t;

t he ma in lnka ge dimen ion in mi metr es inc lu -

in the mast heig t of the fr ame, as tested, r ela -

t ive to t he centr e of t he r ear whe ls (on dr a win )

the temp r atur e of t he hy dra ulc fluid at the star t

of ea ch test in degr ees Celsiu ;

the c a lc ula ted moment a r ou d t he r ear ax le in

terna l lf t for ce at the frame which c a n b exer t ed

t hrou h t he ful r a nge of movement

NOT E 4 A s it a ble test r ep&t form is s own in

anne x A

NOT E 5 This test is o t iona l at t he r eq est of t he ma nu-

f actur er

6.2.1 Sec r e the tr actor in ac or dan e wit h 6.1

6.2.2 Ap ply a downwa rd v er t ic a l for ce eq a l to t he

maximum v er t ic a l for ce which c a n b s p or ted by

the hy dra ulc lf t t hrou hout t he ful r a nge of mov e-

ment (se 6.1.3) to t he frame at it s centr e of gra vity

a nd ma int a in it throu hout t he test

6.2.3 With the hy dra ulc lf t a nd it s contr ols in t he

a nd me s r e the v er t ic a l heig t of the p int of a ppl-

c a t ion of the for ce

p r ted:

a) t he for ce a ppled to t he frame;

6.2.4 At int er va ls of 5 min ov er a p r iod of 3 min

r eme s r e t he v er t ic a l heig t

b) t he decr ease in the heig t of the p int of a ppl-

c a tion of the for ce afer ea c h 5 min interv a l;

c) the ambient temp r atur e at the star t of mea su n

A nnex A

(nor mativ e)

Tr ac tor ma nufa ctur er ’ name a nd ad r es :

Date a nd loc a t ion of tests:

A 2 Spe ific tion of tra tor Tra tor Model: Ser ia l No.:

Ma ss wit h tanks ful but wit hout ba lla st or d v er : k g En in Make:

Ty pe:

Rated sp ed: min-1 Model:

Ser ia l No.:

Hy ra lc fluid u e in te ts Ty pe: V isc osity : mm+ NOT E 6 1 mm*/ s = 1 cSt V isc osit y in ex :

Ty pe of hy dra ulc s stem:

Heig t of lower hitc

Vertic l

f ul ra g

Pr es urel)

k Pa

a o t

re r

a le

k N.m

T ilt a gle of ma t

o er ra g of lf

degr ees

I

I) 9 % of minimum relef valve pr es ur e setin

1

T emp r atur e of hy dra ulc f luid:

“C

For ce a ppled to frame: k N

Ambient temp r atur e at t he star t of mea su n : “C

5

IO

15

2

2