In automobile safety, an air-bag is a safety restraint device made up of a bag which inflates during a collision to prevent passengers from being propelled forward. There are two types of airbags: frontal and side-impact airbags (Sass) which are found in newer models. The airbags general purpose is to protect passengers from the impact of a crash and from hitting interior objects in the car like the steering wheel. More specifically, the side-impact airbags help protect your head and chest during a collision with the side of the automobile.
The major com opponents of the airbag consist of the crash encores, the inflator (also called the airbag module), the bag and the diagnostic monitoring unit. Once the crash sensor detects a collision, it sends a signal to the inflator causing a chemical reaction which rapidly inflates the bag. The bag will then deflate itself to allow the passengers to be able to move after the accident. These components are all powered by the vehicle’s battery and hold a reserve charge in case the ignition has been turned off or the battery has been disconnected. Originally, the airbag was used as a seat belt replacement since seat belt usage rates were quite low. However, those initial air bags were responsible for some fatalities and with the introduction of mandated seat belt restraints, airbags became a supplemental restraint system (SIRS). 2 The first major component is the bag which is composed of a thin nylon fabric with tiny holes in it and is folded typically into the steering wheel or dashboard. G Newer vehicles may have airbags in other places such as the door or seat.
There is no standard size for an airbag and it is customized to fit each car model. The second major component is the crash sensor which is an electric sensor and varies in design and location based on vehicle’s make. There are typically one to three crash sensors in cars and they are usually located in the crush zones. 4 The two possible designs are a “ball and tube” mechanism or an accelerometer built into the microchip in newer automobiles. 5 The third major component is the inflator, also called the airbag module.
This is composed of an igniter, a filter and a storage compartment which stores sodium aside (Anna) and potassium nitrate (KNEW) used to inflate the bag. 6 The inflator is attached to the bag and therefore it is in the same location as the bag. Once again, this component varies in size and shape depending on the vehicle model. The final major component is the diagnostic monitoring unit which serves to diagnose the different components of the airbag, indicated by a light on the dashboard. 7 This is necessary since components can go years without needing to be used.
This unit is located somewhere in the circuitry’, dependent again on the vehicle’s make. The components are powered by the battery and are capable of holding a reserve charge should the ignition be turned off or the battery disconnected. A typical holding charge would last between one second and ten minutes. Once a collision of sufficient force occurs, a mechanical switch is flipped inside the sensor which closes an electrical contact, informing the crash sensor that a collision has occurred. Older vehicles use “ball and tube” mechanism to close the electrical contact whereas new vehicles use an accelerometer which detects sudden deceleration. The “ball and tube” mechanism consists of a small ball held in place by a magnet. During an accident, the ball gets dislodged from the magnet and rolls forward in the tub which completes the electrical contact. 9 For most vehicles, the collision force must be equal or greater than hitting a solid barrier at 12 to 15 miles per hour r hitting another car at 25 miles per hour in order to trip the sensor. 0 The crash sensors are designed to prevent the air bag from inflating when the car goes over a bump or a pothole, or in the case of a minor collision. Advanced frontal air bags can automatically determine the most advantageous level of power to inflate the frontal airbags based on four factors which are occupant size, seat position, seat belt use of the occupant and crash severity. 1 1 Once the sensor is informed a crash has occurred, it sends a signal to the inflator. The signal tells the inflator to ignite and react sodium aside (Anna) with tootsies nitrate (KNEW) to produce nitrogen gas.
The gas then passes through the filter in the inflator in order to trap unburned particles and help cool the gas. 12 Once the nitrogen gas passes through the filter, it instantly fills up the bag and burst through the surface that stores it. This entire process occurs within 25 or 50 milliseconds which is faster than the blink of an eye. 13 If the process took any longer, the airbags would lose their purpose since the collision would have already come to an end. After the airbag has deployed, it will deflate itself as a result of the tiny holes in the bag.
The deflation of the bag is necessary, if not the passengers would be trapped by the bag and be unable to move. In conclusion, the airbag is safety device in automobiles deployed during a crash which restrains the passengers and prevents them from injury during impact. There exists two different types of airbags, one being frontal airbags and the other being side-impact airbags. The major components of the airbag are the crash sensors, the inflator, the bag and the diagnostic monitoring unit. The operation cycle begins with the crash sensor detecting a collision.
Once the crash is detected, a signal is sent o the inflator which produces a chemical reaction allowing the bag to inflate itself and burst through the surface that is restraining it. This is all happens very quickly as the bag needs to be deployed before the impact comes to an end. After the bag is deployed, it will deflate itself to allow the passengers to move around should they need to. The components are fed by the car’s battery and are capable of holding a charge should anything happen to the car’s battery.