One of the most important control system of an automobile is BRAKE SYSTEM .They are required to stop the vehicle within the smallest possible distance and is done by converting kinetic energy of the vehicle into heat energy which is dissipated into atmosphere.
2. INTRODUCTION
Today’s technology is in need for speed, also safety
as well, for that deceleration is needed engines of
maximum efficiency for maintaining the speed &
brakes of latest technology is used.
Brake system are required to stop the vehicle within
the smallest possible distance. By converting kinetic
energy into heat energy which is dissipated to
atmosphere.
3. MAIN REQUIREMENTS
Brakes must be strong enough to stop the
vehicle within the possible distance in an
emergency. (safety)
Brakes should have good anti-fade
characteristics also on constant prolonged
application its effectiveness should not
decrease.
4. STOPPING DISTANCE OF
A VEHICAL DEPENDS
Vehicle speed
Condition of road surface.
Condition of tyre thread.
Coefficient of friction b/w tyre thread & road
surface.
Coefficient of friction b/w brake disc/drum &
brake pad.
Braking force applied by the driver.
5. TYPES OF BRAKES
According to the purpose
Service or primary brakes
Parking or secondary brakes
According to the construction
Drum brakes
Disc brakes
According to the method of actuation
Mechanical brakes
Hydraulic brakes and Air brakes
Electric brakes
Vacuum brakes
According to the extra braking effort
Servo brakes or power assisted brakes
Power operated brake
7. TYPES OF BRAKE MATERIALS
Grey cast iron disc
Heavy
Rust formation
Aluminum disc
Light
Less resistant to heat and fade
Carbon-fiber disc
Heat resistant
Needs high working temperature
Ceramic disc
Inorganic and non-metallic
Hard and brittle material
High heat and abrasive resistance
Can sustain large compressive load
8. CERAMIC DISC BRAKES AND
CONVENTIONAL DISC BRAKES
Grey cast iron disc is heavy which reduces
acceleration, uses more fuel.
Ceramic disc brake weighs less than conventional
disc brakes but have same frictional values, used in
F-1 racing cars etc.
CDB good at wet conditions but conventional disc
fails in wet conditions.
CDBs are 61% lighter, reduces 20kg of car, apart we
can save the fuel, resulting in better mileage.
Improve the shock absorber. We can add more
safety features instead of the current weight.
9. MANUFACTURE OF CERAMIC
DISC BRAKE
In earlier days disc brakes were made from
conventional brittle ceramic material.
DIAMLER CHRYSLER made carbon fibre reinforce
brake disc to avoid the brittle property.
Short carbon fibres + carbon powder + resin
mix(at 1000ْc sintering) = stable carbon frame
work.
After cooling ground like wood brake disc
obtains its shape.
Add silicon to the required shape and insert in
the furnace for the second time.
Resins : thermo plastics resins and thermo setting
resins .
10. COATING OF CERAMIC ON
CONVENTIONAL BRAKE DISCS
FRENO Ltd. used metal matrix composite for disc,
an alloy of aluminum for lightness and silicon
carbides for strength. The ceramic additive made
the disc highly abrasive and gave a low unstable
coefficient of friction.
SULZER METCO Ltd. special ceramic coating,
developed thermal spray technology as well as
manufacturing plasma surface.
11. PORSCHE CERAMIC COMPOSITE
DISC BRAKES (PCCB)
This is manufactured
using a high vacuum
process.
The process involves
heating carbon
powder, resins and
carbon fibres in a
furnace at 1700ْc
12. PROPERTIES OF PCCB
CDB with the involute cooling ducts for an
efficient cooling.
Offers braking response, fading stability, weight &
service life.
PCCB ensures maximum deceleration from
without any particular pressure on the brake
pedal.
Superior response under wet condition.
New braking linings cannot absorb water.
Cross drilled brake discs help to optimize
response of the brakes also in wet weather.
13. ADVANTAGES
50% lighter than metal disc brakes, reduces 20kg of car.
Apart from saving fuel also reduce unsprung masses
with a further improvement of shock absorber response
& behavior.
High frictional values in deceleration process Porsche-
100 to 0 km in 3 sec.
Brake temperature resistance up to 2000 ْc .
Still runs after 300000 km need not change CDB.
No wear, maintenance free and heat and rust resistant
even under high oxygen concentration.
15. APPLICATIONS
FORMULA-1 cars and sports cars
Porsche 911 turbo- with a top speed of 305 km/h
and acceleration from rest to 100 km/h in 4.2s. Its
engine 3.6 L with 420 hp max torque 560 Nm is still
running with PCCB.
911GT2 and Mercedes Benz’s futuristic vision GST is
going to reinforce CDB .
19. CONCLUSION
CDB due to its advantages over the conventional
brake discs are going to be the brake disc for cars
in the future. With the success of Porsche turbo
car, many other racing cars and commercial
vehicles are going to implement CDB in cars.