TIAGO

BRAKES

6.5 NESSECITY OF ABS with EBD

Whenever the brakes are applied, the Vehicle

wheels transmit this braking force to the road

surface. To achieve optimal deceleration each

wheel should be braked to the point of imminent

lock. In this manner maximum possible braking

force would be imparted to the road surface.

However if a wheel is braked be- yond this level it

will lock which can result in the vehicle skidding

and the driver losing control.

EBD:

During normal braking there is always a level of

load transfer from the rear axle to the front. During

this occurrence it is necessary to ensure that the

rear axle wheels do not reach the point of lock

before the front axle wheels.

On vehicles without ABS and EBD this is

achieved through the use of a pressure conscious

regulating valve (PCRV) which limits the pressure

to the rear axle to give a front first locking

sequence. The PCRV allows only a

predetermined pressure to the rear wheels to

avoid locking of the rear axle wheels before the

front axle wheels. As a mechanical fixed ratio

component it cannot adapt to the condition of the

vehicle brakes, tires or to the road or vehicle load

conditions, and hence it cannot achieve ideal

braking at the rear axel

To enable optimum braking at the rear axle while

maintaining vehicle stability during braking EBD is

provided. It enables the distribution of brake force

between the front and rear axle brakes to be

adjusted throughout the vehicle life, irrespective of

the condition of the vehicle brakes, tires; or to the

road, vehicle load conditions.

In the case of EBD failure the driver will be

alerted.

ABS

In emergency braking conditions and when driving

on wet or slippery road surfaces like snow and

Ice, gravel, steel plates and bridges etc.. it is

possible that the braking forces at the wheel

exceed those possible wheel locking limits.. This

will result in wheel locking (stopping rotating). If

one or more wheels locks during braking, the

vehicle can go into a skid and no longer be

controlled by the drive as he will have lost steer

ability.

To avoid the wheels from locking and prevent the

vehicle from skidding ABS is provided. It prevents

the wheels from locking and maintains the steer-

ability of the vehicle thereby helping the driver to

maintain stability of the vehicle while bringing it to

a stop in the safest possible way.

In the case of ABS failures the driver will be

alerted and the conventional braking circuit will

still be operational.