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Begin OCR Text:
_
P l 2 O. P l 8OO
GROUP 6O
W H E E L A L l _ N M E N T
' In order for the vehicle to hove good steering VER7lCA L Ll N E
properties ond o minimum of tyre weor, the _
Front wheels must hove certoi n pre-determi ned - _
settings, generolly known os wheel olignment. (
__i
Wheel olignment consists of coster. comber. king
pi n i ncli no1ion, toe-ou1 ond toe-in. j
_
CA5rER _ 'i Ii
l
_ Coster generolly reFers to the longitudi no l i ncli_ i _
no1ion (forwords or bockwords) of the ki ng pi n. f _i
On these vehicles. which do not hove o king pin. i _ l_i
coster consis1s of the o ngle between o verticol 'i
_ li ne ond o li ne 1hrough 1he centre oF the boll _, _ _. ,
ioints (A. Fig. _ ). _ _ _
l_ 1,
Coster hos the effect of cousi ng the wheels to l_, l ,_ /
run stroight forwords thereby focilitoting steer- ' --
_
ing . z__oz
Fig . 2. Comber ond ki ng pin inclinotion.
CA__E_ B - King pin in_linoIion
C = Comber
Com ber is the inclinotion Df the wheel itself out-
words or i nwords. Comber is positive if the
w_,,_ ;, ; ,,__,_,d ou_wo,d, (C. F_,g. _) ond n,go- KING PIN l NCll NArION
tive if the wheel i nclines inwords. Foulty comber King pin i nclinotion meons 1he inclinotion of 1he
co uses u neven tyre weor. ki ng pin i nwords. Si nce 1hese cors do not hove
o king pi n, the iffcli notion is represented by the
ongle Mode between o verticol li ne ond o line
_ vE___CA_ ___ E through the centre of the boll i Dint ( B, Fig. 2).
_ Ki ng pin incli no1ion couses the centre li nes oF
the boll ioi nts ond the wheel 1o opprooch eoch
other towords the rood surfoce. l n this woy the
wheels ore eosier 1o turn. _he i ncl inotion olso
' _ ossists the tendency of the wheel to run stroight
forwords since the cor is lif1ed very sligh1ly when
\ the wheels ore turned.
\ roE-o_
_ When driving round o bend the wheels roll ot d if-
_ , '_, Ferent rodii . In order for 1hem 1o hove the some
' I // pivoting centre. ond consequently mi nimum tyre
' / weor, the frDnt wheels mus1 be 1urned to dif-
wwo Ferent e_tents. _his relotionship. known os toe-in,
_ l IlOl is de1ermined by the shope of the steeri ng rod
_ Fig. l . Coster. ond steeri ng orms. see Fig . 3. 6- _
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