When will the airbags in a car deploy?

Depending on the collision, the car's airbags will deploy or not to protect the occupants.

Nowadays, airbags are considered an indispensable safety equipment in cars. So what is an airbag and why is it so necessary in cars?

Not all airbags must deploy in a collision. Photo: Reuters

The operating principle of the airbag is basically quite simple. The electronic controller will receive signals from sensors to determine the deceleration of the vehicle. When the controller receives a large enough deceleration signal (a collision occurs), it will provide the corresponding airbag detonation current.

The airbag explodes very quickly (about 10 to 40 thousandths of a second), creating an air cushion to prevent the passenger's head and chest from directly colliding with the vehicle's hardware. After the passenger is protected from the impact, the airbag will automatically deflate quickly to avoid trapping the passenger in the vehicle.

After the passenger has been protected from impact, the airbag will automatically deflate.

Airbag deployment depends on two basic factors: the vehicle's impact force (which causes the vehicle to decelerate) and the impact area and direction (the point and direction of the initial impact). On most Ford vehicles and some other vehicle manufacturers, the airbag will deploy when the deceleration is at least 2 G (G: acceleration due to gravity) or the minimum impact force equivalent to the case of a vehicle reaching a speed of about 25 km/h and colliding head-on with a fixed concrete wall.

Suppose, when the car is running at 120 km/h and suddenly brakes to stop the car, the maximum deceleration = 1.5 G, so the deceleration of 2 G to deploy the airbag must be much greater than the gradual deceleration when braking suddenly. Therefore, in some cases, after an accident, the car's exterior looks very damaged but the airbag does not explode because the car's gradual deceleration has not reached the allowable limit to detonate the airbag.

In these cases, the seat belt system is enough to keep passengers from serious injuries. Therefore, all vehicle manufacturers' user manuals require passengers to always wear seat belts when sitting in the car. This is also a mandatory law in many countries around the world, including Vietnam.

Not all airbags deploy in a collision. For example, side and overhead airbags are designed to deploy in a severe side impact. In a side or frontal impact that does not involve the passenger compartment, these devices may not deploy.

Thus, whether the airbag deploys or not depends on many factors such as impact force, impact angle, seat belt usage, and how the airbag threshold is set by each car manufacturer.

According to Thanhnien.vn