Airbag inflation saved thousands lives. But do you know how it works ??
Today in this article we will uncover the working of airbag system. There are airbags at the front of the dashboard in most cars, and many vehicles have airbags along the side of the car as well. These bags are compressed and kept in a small area. It can be very helpful in cushioning the passengers in a car in many cases.
Crash Sensor
This is the most important part behind the success of airbag. Sensors are small electrical part which determine the shock , speed , sudden stopping, increased pressure as pieces of the car are moved due to the force of the collision, and more. Two types of airbag sensors used in cars are electrical and mechanical. Electrical sensors vary in design. Some use an electromechanical "ball and tube" mechanism, which basically consists of a small tube containing a circuit switch and ball that's held together by a small magnet. If a collision occurs, the ball is dislodged from the magnet and rolls forward in the tube, hitting a switch that completes the electrical circuit. Other electrical designs are similar in principle, using a metal roller or spring loaded weight instead of a ball, or in newer cars, an accelerometer to trip the sensor. Mechanical sensors work independent of the electrical system and respond similarly to the electrical sensors, with a design that actuates a firing pin triggering a small explosion after a crash. Since a mechanical sensor does not require a power source, it cannot be deactivated like an electrical sensor can when the battery is disconnected.
The success of the airbag system relies upon the crash sensors working not only accurately but also extremely quickly, so the most expensive and technologically advanced part of the airbag system are here.
Inflation of Airbag :-
There is combination of potassium nitrate (KNO3) and sodium azide (NaN3) which form nitrogen gas. Hot discharges of this gas inflate the bag at a speed of roughly 200 mph. Immediately after inflation, the gas is dispersed through tiny holes in the airbag, which causes it to deflate. The entire process takes about 1/25 of a second.