The document discusses the automatic air suspension system, which replaces conventional coil spring suspension. It works by using air bags and height control valves to automatically adjust the vehicle's height based on load. The air supply provides pressurized air to inflate the air bags between the frame and axles as needed. The height control valves control air flow to maintain proper ride height when weight is added or removed from the vehicle. The air suspension system provides benefits like improved ride comfort and handling, while protecting the vehicle from damage.

1. # MECH
WELCOME

2. “AUTOMATIC AIR
SUSPENSION SYSTEM”
S.BHEEMESWARA RAO
U14ME351 – E Sec
MECHANICAL DEPT
BHARATH UNIVERSITY

3. OUTLINE
 Introduction
 Role of air suspension system
 Principle of air suspension system
 Components of air suspension system
 Working of Air suspension system
 Advantages
 Disadvantages
 Conclusion

4. INTRODUCTION
 ‘The automatic air suspension system is an air-operated,
microprocessor controlled suspension system.
This system replaces the conventional coil spring suspension and
provides automatic front and rear load leveling. The air bags,
made of rubber , support the vehicle load at the front and rear
wheels’
 Sir William Brush is the father of suspension system in
automobiles

5. ROLE OF AIR SUSPENSION
SYSTEM
 The main role of air suspension system are as follows:
 A . It supports the weight of vehicle.
 B . Provides smoother ride for the driver and passengers i.e. acts as cushion .
 C . Protects your vehicle from damage and wear.
 D . It also plays a critical role in maintaining self driving conditions.
 E . It also keeps the wheels pressed firmly to the ground for traction
 F . It isolates the body from road shocks and vibrations which would otherwise be
transferred to the passengers and load

6. PRINCIPLE OF AIR
SUSPENSION
Principle :- When a tire hits an obstruction, there is a reaction force.
The size of the reaction force depends on the un-sprung mass at each
wheel assembly.
in general, the larger the ratio of spring weight to un-sprung
weight, the less the body and vechicles occupants are affected by pumps,
dips, and other surface imperfections such as small bridges. A large spring
weight to un-sprung weight ratio can also impact vehicle control.

7. COMPONENTS OF AIR
SUSPENSION
There are three fundamental components of air
suspension system .
A . The air supply
B . Air bags
C . Height control valves

8. AIR SUPPLY
The air supply is engine air compressor, the air tanks, air valves and
air lines.
 The engine air compressor supplies air for every piece of air
equipment on the vehicle.
 The maximum pressure supplied by the compressor varies. For many
years, the air supply was maintained around 120 to 125 psi but on some
newer, larger vehicles this has been increased to 135 psi.
 There will be dash gauges that will supply system pressure
information but all vehicle shave what we refer to as a “pop off valve”.
 One can hear the valve “pop off” when the system reaches the
maximum air pressure.

10. Air bags are made of rubber bladder that holds air.
 Air bags are also referred to as air springs or bellows.
 The air bags are located between the frame of the vehicle and the vehicle
axles.
Air bags are rated for weight and pressure capacities.
 Air bag placement and arrangements vary amongst chassis manufacturers.
 At the very least, there will be one air bag for each side of each axle in the
vehicle.
 There can be two air bags for each side of the axles but there is no system
with more than one bag per side.
AIR BAGS

12. The height control valves (HCV) are kind of the brains of the system.
They dictate how much air is in the air bags.
This dictates the height the vehicle sits at, therefore they are known as
Height Control Valve.
 Most HCVs are mechanical valves but electronic HCVs are available.
The HCV is mounted to the frame of the vehicle.
HEIGHT CONTROL VALVE

14. WORKING OF AIR SUSPENSION
SYSTEM

15. The vehicle air system, engine air compressor, tanks, lines, etc., supplies air to
the height control valves (HCV) mounted to the frame of the vehicle.
The height control valves are connected to the air bags with an air line. The
linkage which connects the HCVs to the axles rotates the HCV as it moves up
and down.

16. When weight is added to the vehicle or transferred through the suspension of the vehicle, the air in
the air bags is compressed, the frame moves closer to the axle. This forces the HCV linkage up. As
the linkage moves up, the valve of the HCV connects the air supply to the air bags. The added
pressure and volume inflates the air bags, causing the frame to move away from the axle. As the
frame moves back to the proper ride height, the HCV linkage moves to the neutral position. This
moves the valve away from the air supply and locks the air in the air bag to maintain the proper
ride height.
.

17. .
When weight is removed from the vehicle or the suspension shifts weight away, the existing
pressure in the air bags can push the frame away from the axle. The HCV linkage is pulled down.
This connects the air bags to the HCV exhaust port. As air is exhausted from the air bags, the
frame lowers back down towards the axle. As the linkage moves up to the neutral position, the
exhaust port is closed and the air is again locked in the air bags, maintaining proper ride height.
These three drawings show a schematic example of the height control valve in the neutral
position, inflate position and deflate or exhaust position.

18. ADVANTAGES
Excellent Suspension & Comfort to passengers
Fully Automatic Level Control
Good Handling
Shields the vehicle from damage
Keeps The Tires pressed Firmly to ground
Easy To Service
Lifting & Levering Function
Increase life of vehicle

19. DISADVANTAGES
Heavy and Complicated
High maintenance costs
Slow response
Bad wheel moment
Ride Quality

20. CONCLUSION
 From the whole discussion in suspension system, I observe that
suspension system is like a white blood cell As white blood cell . As
white blood cell provides energy to body to fight against diseases or
viruses which try to destroy or try to decrease our life , in similar way
SUSPANSION SYSTEM provides the energy to a vehicle to protect
itself from damaging, increasing life of the vehicle , increase the
handling , increase the comfort of passengers and many more .
 So, according to me if you remove the suspension system, then you feel
like in bull-cart in Audi , Mercedes types luxurious cars. The only
difference is speed .
 So, The Scope Of The Suspension System is Too Bright.