What is the structure of an airbag?
2 Answers
The airbag system consists of an integrated airbag module comprising the airbag and inflator (gas generator), a collision sensor system that detects impacts and sends deployment signals to the airbag module, and wiring harnesses that transmit signals from the sensors. The driver's airbag is stored within the steering wheel pad. Therefore, if the steering wheel is labeled with "SRS" or "Airbag," it indicates the vehicle is equipped with an airbag. When the car experiences a high-speed frontal collision within a certain angle, the collision sensor mounted at the front of the vehicle and the safety sensor located in the middle of the car detect the sudden deceleration. This signal is transmitted within 0.01 seconds to the airbag system's control unit. After analysis and confirmation, the control unit immediately triggers the electrical igniter (squib) inside the airbag, causing it to explode—a process that typically takes about 0.05 seconds. Once the igniter is triggered, solid nitrogen particles rapidly vaporize, generating a large volume of nitrogen gas that inflates the airbag. With strong force, the airbag bursts open the cover on the steering wheel and fully deploys. This creates a "cushion" in front of the occupants. When they impact the airbag, the internal nitrogen gas is compressed and escapes through small holes in the airbag, thereby reducing the impact force and preventing injury to the occupants.
I often help friends inspect their cars, and the structure of airbags is actually quite fascinating. The main component is a neatly folded nylon airbag, usually hidden behind the steering wheel or dashboard. The core part is the gas generator, which contains special chemical tablets that rapidly produce a large amount of nitrogen gas when electrified. Upon impact, sensors immediately send signals to the control computer, which determines whether to ignite within milliseconds. When the airbag deploys, it pushes open the plastic cover and has small vent holes on the surface to allow the gas to slowly escape, cushioning the impact and preventing secondary injuries. The entire system, working in tandem with seat belts, securely holds passengers in their seats, making it particularly effective in high-speed collisions.
