automobile

1. AIR SPRINGS
AND
PNEUMATIC SUSPENSION

2. Air Springs
1. Bellows type
2. Piston type

3. 1.Bellows type
•Bellows type air spring consists of rubber bellows, which are
generally of circular in section.
•This type of spring is good replacement for the coil springs.

4. 2.Piston type
•Piston type air spring consists of a metal air container in the form of an inverted
drum.
•The drum is fixed to the frame and the sliding piston is attached to the lower
wishbone.
•For making the system leak proof a seal is provided by flexible diaphragm.
•The diaphragm is secured at its outer circumference to the lip of the drum and its
centre to the piston.

5. Air Suspension
OR
Pneumatic suspension

7. • Air suspension systems are becoming increasingly popular because of
certain advantages they possess over the conventional metal springs.
These are:-
1. A variable space for wheel deflection is put to optimum use by virtue
of the automatic control devices.
2. Since the vehicle altitude remains constant, the changes in head lamp
alignment due to varying load are avoided.
3. The spring rate varies much less between the laden and un-laden
conditions, as compared that of that of conventional leaf springs,
reducing the dynamic loading.
4. The improved standard of ride comfort and noise reduction attained
by the use of air springs reduces both driver and passenger fatigue.

8. •In the lay out shown the four air springs are mounted in the same
positions where generally the coil springs are mounted.
• An air compressor takes the atmospheric air though an air filter and
compresses it to a pressure of about 240 Mpa.
•The same pressure is maintained in the accumulator tank, which is
provided by a safety relief valve.
• This high pressure air goes through the lift control valve and the
leveling valves to the air springs as shown.
• The lift control valve is operated manually by means of a handle on the
control panel through a cable running from the valve to the handle.
•The initial height is adjusted according to the loading conditions.
•WORKING