[Automobile Air Bag] Principle and technical analysis | 4 safety precautions | How to deal with exploded air bags

The earliest concept of airbags can be traced back to World War I, when two British University of Birmingham students of the Institute of Aeronautics and Astronautics invented an "Air Cushion" to protect fighter pilots. This device contains sponge, is covered with rubber, and has air holes to adjust the deflation speed to achieve a cushioning effect. Although it is different from modern car airbags, it laid the basic concept of airbag cushioning protection.

The origin of the car airbag dates back to the 1950s, when American engineers John W. Hetrick Invented and patented the "SRS" (Supplemental Restraint System), but due to the immaturity of the technology, it has always remained in the theoretical and testing stage.

In 1964, Japanese engineers Yasusaburo Koga In collaboration with several universities and the Japanese Ministry of Defense, he proposed the innovative concept of using a small explosive device to quickly inflate an airbag, which became the basis of modern airbag technology. This technology was later introduced to the United States, where Allen Breed improved the trigger sensor, allowing the airbag to inflate in less than 0.03 seconds, improving reaction speed and reliability.

After years of development and improvement, General Motors was the first to launch a mass-produced car equipped with airbags in 1974. In 1980, Mercedes-Benz's S-Class was the first European car equipped with airbags. Today, airbags have become standard equipment in cars.

The working principle of automobile airbags is mainly divided into 4 parts, including electronic sensors, processors, triggers and airbags.The operating principle is that when the sensors installed on the four sides of the car body encounter a serious impact, the processor will calculate different data such as vehicle speed, shock intensity and braking status, so as to determine whether the trigger needs to be detonated. When the trigger is detonated, the chemical propellant inside will explode, and a large amount of gas will be injected into the airbag in a very short time, so that the airbag will be inflated at a high speed (about 230 to 320 kilometers per hour) within 5 thousandths of a second to form a cushion, protecting the driver and passengers from collisions with hard objects such as the steering wheel and dashboard.

Although explosions are used to trigger airbags, the propellants are usually insensitive explosives (such as ammonium nitrate), which will only be triggered under a certain impact force, thus avoiding accidental explosions and ensuring the "safety" of the airbags.

With the evolution of technology, the types and application range of automobile airbags have gradually expanded from being only installed in front of the driver's seat to the co-pilot seat, side, curtain and knee areas, and even applied to motorcycles. Side airbags and air curtains are mainly used to protect the head and side of the body, reducing injuries in side collisions and rollovers, while knee airbags can effectively reduce damage to the area below the knee in secondary collisions.

In addition, modern car designs have also begun to innovate the way airbags are deployed, such as ZF, Germany The new generation steering wheel airbag is designed to deploy from the upper edge of the steering wheel to match the seamless inner cage design in recent years, improving safety and aesthetics.

With the popularization of airbags, almost all cars are equipped with airbags. In fact, airbags are used as an auxiliary seat belt system and cannot replace seat belts. Therefore, they must be used in conjunction with seat belts to fix the passenger's position and understand the safe distance of the airbag to avoid being injured due to being too close when the airbag explodes, so as to achieve the best protection effect.

Although airbags are very reliable, there are still news reports about airbags from time to time, saying that drivers or passengers were injured by airbags that popped out. In fact, in addition to having a correct sitting posture and maintaining an appropriate seat distance, users can find a label printed with "Air Bag" at the location where the airbag is installed, and do not place sundries or decorations nearby to avoid secondary injuries caused by airbag explosions.

According to Transport Department documents of Recommendations: 4 correct ways to use airbags

• Wear seat belts correctly

• Keep a proper distance from the air bag outlet

• Avoid placing debris near the air bag

• Young children should sit in the back seat and use appropriate safety devices

Generally speaking, the airbag indicator light on the dashboard will light up for a short time when the car is started, indicating that the system is checking the airbag system. However, if the airbag indicator light is continuously on, it means that there is a chance that the airbag system is malfunctioning. In this case, you should contact a maintenance technician immediately for inspection.

Although most airbags are made of high-strength and high-temperature resistant fibers such as nylon, and will not break when they explode, the airbags can technically be folded back into place, but the process requires great skill and time, greatly increasing maintenance costs. Therefore, it is recommended that a new airbag assembly be replaced instead, which is more cost-effective.

As for other components such as sensors and triggers, the former is likely to have been damaged to some extent during the collision, and the latter needs to be replaced because the chemical propellant inside has been used. In summary, if the airbag is deployed, the repair cost can easily exceed 10,000 yuan or even tens of thousands of yuan (depending on the number of airbags deployed). Sometimes it is more reasonable to choose to scrap it rather than repair it.