In the event of a car accident, seat belts are fixed to the body, airbags are used to cushion the impact, and the two designs work together to ensure safety.
The principle of the former is simple, but how exactly do airbags work and how do they protect the safety of drivers? We tried to slow down the time by a factor of 500, and the moment the airbag popped out should look like this:
Airbags were first proposed by Hertrick in August 1953 and were patented for "automotive cushioning safety devices" in the United States. Is a passive safety (see Automotive Safety Performance) protection system that, in conjunction with seat belts, provides effective crash protection for occupants.
In the early days of the birth of airbags, engineers tried to inflate the airbags with compressed air, but the design had two major drawbacks - one was that the perceptron could not accurately determine whether the car had collided; the other was that the compressed air filling speed was too slow and the protection was poor relative to the speed of injury arrival after the accident.
Therefore, American engineer Allen K. Breed designed the "in-tube ball sensor" to improve the perception accuracy and replace the compressed air with the chemical explosive "sodium azide (NaN3)".
When triggered by temperatures above 300°C, this solid chemical quickly decomposes into gas and fills the airbags – from the time they are triggered to when the bladders are fully inflated, the whole process takes only 30 milliseconds.
However, this design also has two disadvantages: after sodium azide decomposition, the gas produced is toxic; sodium azide is easy to absorb water, if there is a leak in the design and manufacturing stage, when the airbag is triggered, the sodium azide after absorbing water will explode violently:
Hitting the glasses when the airbag pops out can also cause damage to the eyes, don't ask me how I know.
Mentioned earlier that the seat belt fixes the body, I estimate that there will be readers who will propose to let tomorrow share the working principle of the seat belt, in fact, this we have shared earlier, the article I will not take it out, the following video can still be seen (readers who have not seen it are worth watching):
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