This is a presentation on Hydraulic Brakes and Antilock Braking Systems(ABS) used in majority of Vehicles now a days and one of the most technologically advanced systems in automobile or automotive sector from very basic concepts such as Hydraulics Introduction and Pascal's Law
2. What will u learn ???
(1)Pascal's law of transmission of pressure ;)
(2) How a basic hydraulic system works ;) ;D
(3) How a Hydraulic brake works in a car/bike
(4) How ABS works and why it is considered
as most advanced braking system ;) ; D
(5) And a lots of cleared concepts
3. Principle of transmission of
fluid pressure:
Pascal's law or the
principle of transmission
of fluid-pressure is a
principle in fluid
mechanics that states,
that any force applied to a
confined, incompressible
fluid is transmitted in all
directions throughout the
fluid regardless of the
shape of the container.
4.
5. HYDRAULIC AND
HYDRAULICS
The word "hydraulic" is derived from two Greek words:
"hydro" meaning liquid or water and "aulos" meaning
pipe or tubing. "Hydraulic," therefore, is an adjective
implying that the word it modifies is in some major way
concerned with liquids. Examples can be found in the
everyday usage of "hydraulic" in connection with
familiar items such as automobile jacks and brakes.
As a further example, the phrase "hydraulic freight
elevator" refers to an elevator ascending and
descending on a column of liquid instead of using
cables and a drum.
6. On the other hand, the word
"hydraulics" is the generic name of a
subject. According to the dictionary
"hydraulics" is defined as a branch of
science that deals with practical
applications (such as the
transmission of energy or the effects
of flow) of a liquid in motion.
15. Anti-lock braking system (ABS) is an
automobile safety system that allows
the wheels of a motor vehicle to maintain
tractive contact with the road surface
according to driver inputs while braking,
preventing the wheels from locking up
(ceasing rotation) and
avoiding uncontrolled skidding.
18. A speed sensor is used to determine
the acceleration or deceleration of the
wheel.These sensors use a magnet
and a coil of wire to generate a signal.
The rotation of the wheel or differential
induces a magnetic field around the
sensor. The fluctuations of this
magnetic field generate a voltage into
the sensor.
19. Since the voltage inducted on the
sensor is a result of the rotating
wheel, this sensor can become
inaccurate at slow speeds. The
slower rotation of the wheel can
cause inaccurate fluctuations in the
magnetic field and thus cause
inaccurate readings to the
controller.
21. There is a valve in the brake line
of each brake controlled by the
ABS. On some systems, the valve
has three positions:
In position one, the valve is open;
pressure from the master cylinder
is passed right through to the
brake.
22. In position two, the valve blocks the
line, isolating that brake from the
master cylinder. This prevents the
pressure from rising further should
the driver push the brake pedal
harder.
In position three, the valve releases
some of the pressure from the
brake.
24. The pump in the ABS is used
to restore the pressure to the
hydraulic brakes after the
valves have released it.
A signal from the controller will
release the valve at the
detection of wheel slip.
25. After a valve release the pressure
supplied from the user, the pump is
used to restore a desired amount of
pressure to the braking system.
The controller will modulate the
pumps status in order to provide the
desired amount of pressure and
reduce slipping.
27. The controller is an ECU type unit in
the car which receives information
from each individual wheel speed
sensor, in turn if a wheel loses traction
the signal is sent to the controller, the
controller will then limit the brake force
(EBD) and activate the ABS modulator
which actuates the braking valves on
and off.