Page 314 - Automotive Engineering Powertrain Chassis System and Vehicle Body

Tyres and wheels C HAPTER 10.1

1.2
F Z,W = 1.0 kN
2.0
3.0
1.0
4.0
5.0 kN, 175/70 R 13
0.8
Lateral coefficient of friction µ Y,W 0.6
5.0 kN, 155 R 13

0.4

0.2

Slip angle α

Fig. 10.1-45 Lateral coefficients of friction m Y,W as a function of the slip angle a and the vertical force F Z , W , measured on a dry
drum on a 175/70 R 13 82 S tyre at p T ¼ 2.0 bar. The tyre, which has been inflated in such a manner, carries 395 kg or
F Z,W ¼ 3.87 kN. In order to indicate the influence of the cross section on the transferable lateral forces the 82 series 155 R 13 78 S
tyre was also included.

bend and negative angles ( E W ) on the inside of the If a wheel is ‘cambered’ against this, in other words
bend as a consequence of the body roll. The lateral inclined at the top towards the outside of the bend,
forces are directed to the centre point of the bend. the possibility of transferring lateral forces reduces; on

Fig. 10.1-46 Lateral force F Y,W dependent on vertical force F Z,W and tyre sizes of different H/W ratios: 165 R 13 82 H, 185/70 R 13 85 H
and 195/60 R 14 85 H. Up to F Z,W ¼ 4000 N the curves are more or less the same, but at higher loads the more favourable lateral
cornering properties of the wide tyre are evident.

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