During the running of the car, the sensor system continuously sends the speed change (or acceleration) information to the control device, and the control device (central controller) makes analysis and judgment. If the measured acceleration, speed change or other indicators exceed the predetermined value (that is, a real collision occurs), the control device sends an ignition command to the gas generator or the sensor directly controls the ignition. After ignition, an explosion reaction occurs to generate N2 or release the compressed nitrogen in the gas storage tank to fill the collision airbag. When the passenger touches the airbag, the collision energy is damped and absorbed by the exhaust hole on the airbag, thus protecting the passenger.
There are substances such as sodium azide (NaN3) and ammonium nitrate (NH4NO3) in the airbag of automobile. When the car is violently hit at high speed, these substances will decompose quickly, producing a lot of gas and filling the airbag. Sodium azide decomposes to form nitrogen and solid sodium, and ammonium nitrate participates as oxidant.
The new airbag is equipped with a device that can inflate or release pressure in stages, so as to prevent the huge pressure caused by sudden explosion from hurting people's heads, especially if passengers are not wearing seat belts, which may lead to life-threatening. Specific forms are:
1, staged ignition device, that is, the gas generator is ignited in two stages. The first stage produces about 40% gas volume, which is much lower than the maximum pressure, which has a buffering effect on human head movement, and the second stage produces residual gas, reaching the maximum pressure. Generally speaking, the maximum pressure of two-stage ignition is less than that of single-stage ignition. In this form, the pressure gradually increases.
2. Pressure relief in stages: the bag is provided with pressure relief holes or holes with adjustable pressure, which can be divided into the way of completely pushing open the air pressure or the computer-controlled pull ring tether. In this way, first, the pressure reaches the set limit, and then the pressure is released instantly to avoid excessive injury.