How much do you know about car tips and airbags?

Hello, I'd like to introduce the working principle of airbag to you.

When the car has a frontal collision accident, when the airbag control system detects that the impact force (deceleration) exceeds the set value, the airbag computer immediately switches on the electronic tube circuit in the inflatable element to ignite the ignition medium in the electronic tube, and the flame ignites the gunpowder and gas generating agent to generate a large amount of gas. The airbag inflates within 0.03 seconds, so that the airbag expands rapidly, breaks through the decorative cover on the steering wheel and blows to the driver and passenger, so that the driver and passenger's head and chest are pressed against the airbag filled with gas.

Airbags can evenly distribute the impact force on the head and chest, prevent the fragile passengers from directly colliding with the car body, and greatly reduce the possibility of injury. Airbags can effectively protect passengers in a frontal collision. Even if you don't wear a seat belt, the anti-collision airbag is still enough to effectively reduce injuries. According to statistics, when a car with airbags collides head-on, the degree of passenger injury can be reduced by as much as 64%, and even 80% of passengers are not wearing seat belts! As for the collision between the side and the back seat, it still depends on the role of the seat belt.

In addition, when the airbag bursts, the volume is only about 130 decibels, which is within the human body's tolerance range; 78% of the gas in the airbag is nitrogen, which is very stable and harmless to the human body; The powder brought out during the explosion is lubricating powder to keep the airbag from sticking together in the folded state, which is harmless to human body.

Everything is a double-edged sword, and airbags also have their unsafe side. According to the calculation, if the car is driving at a speed of 60km/h, the sudden impact will stop the car within 0.2 seconds, and the airbag will pop up at a speed of about 300km/h, and the resulting impact force is about 180kg, which is unbearable for fragile parts of the human body such as the head and neck. Therefore, if the angle and strength of airbag ejection are slightly wrong, it is possible to brew a "tragedy".

When the car is running, the three sensors constantly input the information of speed change into the electronic controller, and the electronic controller constantly calculates, analyzes, compares and judges, and is ready to issue instructions at any time. When the vehicle speed is less than 30km/h, the front sensor and the safety sensor connected in series input collision signals to the electronic controller at the same time, giving instructions to detonate the electric detonator of the seat belt pretensioner, but the signal from the central sensor cannot make the electronic controller give instructions to detonate the electric detonator of the airbag. Therefore, in the case of low-speed collision (small deceleration), as long as the pretensioner tightens the seat belt backwards, it is enough to protect the driver and passenger from being collided forward.

In the case of high-speed (large deceleration) collision, the front sensor and the central sensor input collision signals to the electronic controller at the same time, and the electronic controller gives instructions after quick judgment, and simultaneously detonates the left and right pretensioners and the double airbag electric detonator. When the seat belt is tightened backward, the two airbags are deployed at the same time, absorbing the collision energy generated by the driver and passenger's deceleration, and effectively protecting their safety.

When a car collides with a fixed object in front, the faster the car travels, the greater the deceleration, and the greater the force on the sensor. If the preset forces of the front sensor and the central sensor are divided into upper and lower limits, that is, the preset collision speed of the front sensor is less than 30km/h, and the preset value of the corresponding safety sensor is also the lower limit, then the electronic controller will only detonate the seat belt pretensioner when the car collides at a low speed. If the preset value of the central sensor is the upper limit, when the automobile collides at high speed, the front sensor, the central sensor and the safety sensor simultaneously output collision signals to the electronic controller, and the electronic controller detonates all electric detonators, so that the safety belt is tightened and the airbag is inflated.

It takes about 10ms for the sensor to send a signal from the collision to the controller to judge to detonate the electric detonator. After detonation, the gas generator produces a large amount of nitrogen, which makes the airbag expand rapidly. From collision to airbag formation to seat belt tightening, the whole process takes 30-35ms, so the protective effect of airbag system is very good.

When the airbag is detonated, the pressure of the airbag increases due to a large amount of generated gas flowing into the airbag, which is not conducive to absorbing collision energy. Therefore, there are two exhaust holes at the back of the airbag, which is beneficial to protect the safety of drivers and passengers.

As an auxiliary configuration of passive safety of car body, people pay more and more attention to it. When a car collides with an obstacle, it is called a primary collision, and passengers collide with internal parts of the car, which is called a secondary collision. The airbag quickly opens the air cushion filled with gas after the first collision and before the second collision, so that passengers can "jump on the air cushion" when they move under inertia, thus reducing the impact on passengers, absorbing collision energy and reducing the degree of injury of passengers.

Airbags have developed rapidly in recent years and their prices have dropped sharply. Cars equipped with airbags have also developed from middle and high-end cars to middle and low-end cars. At the same time, some cars are equipped with passenger airbags (double airbags) in the front row. The airbags used by passengers are similar to those used by drivers, but they are larger in size and need more gas. Since 1990s, the safety performance of airbag has been generally accepted and regarded as a modern advanced safety device. Understanding the working principle and precautions of airbags is very important for us to better protect ourselves, but for drivers, safe driving is the first priority, which is irreplaceable by any advanced safety device!

I hope I can help you.

Xilili Waterway, Nanshan District, Shenzhen 1052