Air suspension for all four wheels:
What is a 4-wheel air suspension? In this type of air suspension, an airbag is used to suspend each wheel.
Basically, each air spring device is a resilient air bag that is covered by a metal cover. This bag is filled with compressed air that bears the weight of the car. When a wheel on the road is justified by an obstacle, the more compressed air dissipates the impact. An air compressor or air pump provides the necessary air to the shock absorber device. The air compressor usually rotates with the motor impeller belt. The pressure in the air tank is maintained at 300 pounds per square inch (approximately 21 kg / cm²). Air is supplied to four airbags through two circuits. In one circuit, the pressure is reduced to 160 psi (approximately 11.2 kg / cm²) by a regulator. This pressure is applied to the four wheels via height control valves. These valves are attached to the car frame and their levers are connected to the wheel suspension. When there is not enough air in an airbag, that side of the car will go down. This causes the connecting rod to move the horizontal lever and open the valve to allow more air to enter the airbag.
A pressure of 300 psi (approximately 21 kg / cm²) is used to correct the extra load on the car. This pressure causes the car to be kept at a fixed level with or without a passenger. The action that takes place in the device is as follows, when it is opened in the car, the door switch is connected to turn on the light inside the car. At the same time, the solenoid of the air suspension is connected to the battery via a switch and the solenoid valve is opened. In this case, the air reaches the horizontal valves with a pressure of 300 psi. If the airbag is compressed due to weight gain (such as when a passenger enters a car), the horizontal valve quickly applies extra air pressure to the low airbag and raises it to the proper level. On the other hand, if the passenger goes out, the airbag lifts. Now the balancing valve removes air from inside the bag until it is lowered to the bottom.
Some vehicels have a special control that the driver can use to enter the airbags with more pressure. This car in some cases, such as when the car passes a sharp turn or moves on a road that is high and low.
Air suspension for rear wheels:
It is used in most passenger cars in which rubber air bladder(rubber airbag or rubber bellow) are placed inside helical springs.
This suspension includes a height control valve and an air compressor that work in a simple way.
When the rear of the car is moved by an extra load, the air height control valve moves from the compressor to the rubber air suspension strut (located inside the rear helical spring), causing the rubber air shock strut to expand and raise the rear of the car. They are also leveled. When the extra load is removed from the car, the rear of the car goes to a higher level and the air height control valve comes out of the rubber air spring and allows the car to be positioned at the previous level.