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The ideal process of seat belts is: firstly, tighten them in time and "press" people on the seat without hesitation at the first moment of the accident. Then, relax moderately. When the peak impact force has passed or people can be protected by airbags, relax the seat belt appropriately. Avoid rib damage caused by excessive tension. The most advanced seat belts are equipped with pre-tightening devices and tension limiters. Let's take a look at their functional principles.
1, seat belt pretensioner accident, people forward, seat backward. At this time, if the seat belt is too loose, the consequences are likely to be: passengers slip out from under the seat belt; In other words, people have touched the airbag, and at this time, the seat belt can't be tightened in time because the tension margin is too large, that is, it can't eat part of the impulse in advance as expected, but hand over all the burden to the airbag. In both cases, passengers may be seriously injured. But the problem is that the seat belt is installed correctly. Where does its loose space come from? First, the occupant's clothes have a certain thickness, and there is a certain loose space hidden in the seat belt device, which cannot be eliminated, but it should be eliminated as much as possible in the event of an accident. What do we do? For this reason, this seat belt pre-tightening device appears, which is responsible for providing instant tightening of the seat belt. Its function process is: firstly, a probe is responsible for collecting collision information, and then an electric pulse is released and transmitted to the gas generator to detonate the gas. The gas generated by the explosion expands rapidly in the pipeline and presses against the so-called ball chain, which makes the ball move forward in the pipeline and drives the pawl disk to rotate. The pawl plate is connected with uranium, and the safety belt is wound around the shaft. To put it simply, the gas pressure makes the ball move, the ball drives the pawl plate to rotate, and the pawl plate drives the shaft to rotate-the pretensioning function of the seat belt is realized instantly. The whole process from accident perception to seat belt pre-tightening is only a few thousandths of a second. There is a cavity at the end of the tube for holding the ball.
2. After the accident of seat belt tension limiter, the seat belt has been tightened under the action of pre-tightening device. However, we hope to reduce the tension of the seat belt immediately after the peak pressure has passed, so as to reduce the pressure of the occupants. This special task is accomplished by the seat belt tension limiter: on the seat belt device, there is a pre-tightening device as mentioned above, and the seat belt is wound under it. Inside the shaft core is a steel torsion bar. When the load reaches the predetermined condition, the torsion bar begins to twist, which loosens the seat belt to a certain extent and realizes the tension limiting function of the seat belt.
Under the joint action of seat belt pretensioner and seat belt tension limiter, the protection ability of seat belt has almost reached the ideal state. As the saying goes, advanced seat belts can really provide reliable safety protection for passengers.
● Topic: Have you fastened your seat belt?
Since the advent of seat belts, I don't know how many lives have been saved. With the appearance of airbags, the safety factor of drivers and passengers has also been greatly improved. However, many people do not pay attention to the importance of seat belts and airbags, and "knowingly commit crimes" and always take chances.
In order to better protect passengers, airbags have become the standard safety configuration of most modern cars. However, when driving and riding, especially in cars with airbags, you must fasten your seat belts!
Because the development and design of airbags are based on the limited protection function of seat belts, seat belts and airbags constitute a SRS-supplementary restraint system. Only when they cooperate with each other can the auxiliary protection function for drivers and passengers be fully exerted.
When there is a strong collision in front of the car, the driver's body moves forward quickly due to inertia. At this time, the seat belt will try its best to "pull" the driver's body and absorb part of the impact energy. At the same time, the airbag will expand and fully open with lightning speed. Then the driver's upper body sinks to the airbag, and the gas begins to escape from the exhaust port of the airbag at a uniform speed, absorbing most of the impact energy; Then, the rider leans back and returns to his seat. The whole process is almost instantaneous, and the driver and passengers are completely passive. In this case, passive reliance on the auxiliary occupant protection system is the only choice.
If the seat belt is not fastened before the collision, the airbag will hurt the driver and passenger. Without the restraint of the seat belt, not only part of the impact energy cannot be "detached" from the driver, but also the rapidly expanding airbag will collide with the rapidly moving driver, and the huge impact force generated by the rapid expansion of the airbag will hit the driver's head and chest heavily. It is conceivable that in this "collision", the driver's head and chest will be seriously injured, and the airbag has become the "culprit" that hurts the driver.
That's why you should always fasten your seat belt! Finally, did you fasten your seat belt?
Seat belt pretensioner
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The characteristic of pre-tightening seat belt is that at the moment of collision accident, before the occupant moves forward, it will tighten the webbing first, immediately tie the occupant tightly to the seat, and then lock the webbing to prevent the occupant from leaning forward, thus effectively protecting the safety of the occupant. The retractor, which plays a major role in pretensioned seat belts, is different from ordinary seat belts. It not only has the function of ordinary retractor to take up the webbing, but also can strengthen the binding force on the passengers at about 0. 1s when the vehicle speed changes sharply, so it also has a control device and a pre-tightening device.
There are two kinds of control devices: one is electronic control device, and the other is mechanical control device. Pre-tensioning devices come in many forms. The common pre-tensioning device is deflagration type, which consists of gas initiator, gas generator, conduit, piston, rope and driving wheel. When a car collides, the pre-tightening device is activated, and the gas initiator at the bottom of the sealed conduit spontaneously ignites, detonating the gas generant in the same sealed conduit. The gas generant immediately generates a large amount of gas expansion, forcing the piston to move upward to pull the rope, driving the driving wheel to rotate the winding reel, and the webbing is wound on the reel, so that the webbing is pulled back. Finally, in an emergency, the retractor will lock the webbing to fix the occupant's body and prevent him from leaning forward and colliding with the steering wheel, dashboard and glass window.
Three-point seat belt
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It is an indisputable fact that seat belts can save lives, but it took both officials and ordinary people a long time to understand this truth. In reducing the consequences of traffic accidents in Qian Qian all over the world, its contribution lies in the fact that when driving, the human body sitting in the car moves at the same speed as the vehicle speed, which is incomparable to any other single safety scheme. When it stops suddenly, the human body will still move at its original speed. This requires a strong, soft and comfortable watch strap to firmly block the impact force between 3000 and 5000 kilograms. Nowadays, this kind of seat belt has become a part of the standard configuration of our car. It was not the automobile industry but the aviation industry that first began to work hard on seat belts. Two former American pilots Hugh? De? Haven and Roger? W? Griswold designed the Y-shaped three-point seat belt, and put the buckle point of the diagonal strap behind the seat-almost behind the occupant. This kind of safety belt is connected to the abdomen with a buckle, and it is called a combined shoulder-waist safety belt. It was patented in 195 1.
Rear seat belt
When the car collides, it can better protect the rear passengers. At the same time, because the safety factor of children sitting in the back of the car is high under special circumstances, if there is a child seat belt in the back, it can play a very good protective role.
Misuse of seat belts
Seat belts are devices used to protect the safety of drivers and passengers. I believe everyone is very clear. However, there are still many drivers who don't wear seat belts when driving. Their attitude is "take them away when you use them, and throw them away when you don't use them." There are even some private car owners who regard seat belts as decorations. I can't bear to wear it unless I meet the police. Seat belts are the protector of life. In real life, some people have gone into a misunderstanding in the use of seat belts.
One of the misunderstandings: Can it be used?
Seat belts have become a veritable "decoration". In fact, this is completely risking your own life. When the vehicle collides or brakes suddenly when driving at high speed, the huge inertia will cause the occupants in the vehicle to collide with the steering wheel, windshield and so on. , thus causing serious harm to passengers. Seat belts can bind people to the seat, and their cushioning effect will absorb a lot of kinetic energy, greatly reducing the degree of injury of passengers. However, due to the lag of ideas, many people are lucky that driving in urban areas will not be too fast, so they rarely have the opportunity to use seat belts. In fact, when a car collides at a speed of only 40 kilometers per hour, the forward force of the car body will be equivalent to dropping a bag of 50 kilograms of cement from the fourth floor, and its momentum can be imagined. So at this time, the role of seat belts is revealed.
Others think that there is an airbag in the car, so there is no need to wear a seat belt. In fact, relying solely on airbags is also very dangerous. Because the explosive force of the airbag is very large, if you directly hit the exploded airbag without the traction buffer of the seat belt, it will also cause serious harm to your body. Therefore, the airbag must be used in conjunction with the seat belt to play its "safety" role.
According to statistics, about 30% passengers survived the traffic accident because they wore seat belts. In other words, a small seat belt saved nearly one-third of drivers' lives. So, don't bother, lift a finger, maybe you can save a life. To paraphrase a well-known slogan: For your safety, please fasten your seat belt.
Myth 2: Throw garbage when not in use.
Seat belts are often neglected in the daily maintenance of automobiles. In fact, like other parts, seat belts should be used and maintained at the same time. Check the performance of the seat belt regularly and replace it in time if it is damaged. All bolts fixing the seat belt to the floor beside the seat should be tightened as required, and sealant should be applied around the bolts. When wearing, the waist safety belt should be tied as low as possible, preferably at the hips, not at the waist. The shoulder safety belt should not be under the armpit, but should be hung obliquely on the chest. Don't twist the seat belt, don't hold the bag on your leg or wear thick clothes, so as not to cause the seat belt to be misplaced and affect its normal function. Don't let the seat belt press on hard or fragile objects, such as glasses, pens, keys in clothes, etc., and don't let the seat belt rub on sharp cutting edges, so as not to damage the seat belt, and don't let the seat back tilt too much, otherwise the seat belt can't expand and contract normally. When the seat is empty, the seat belt should be put back into the retractor. If the seat belt is subjected to a strong straightening load in use, even if it is not damaged, the assembly should be replaced and cannot be used again. Seat belts must be installed with the seat, and shall not be disassembled at will, and shall not be interchanged between cars. When the seat belt is too dirty, soft soapy water can be used as cleaning solution and scrubbed with cloth or sponge. Do not use dyes or whitening agents, otherwise it will corrode the seat belt, and do not use a hard brush to brush it, so as not to reduce the tensile strength of the seat belt.
Myth 3: You can use it at will.
Many drivers are injured by seat belts because they don't pay attention to the correct use of seat belts. The main reason for being injured by the seat belt is that when the car suddenly brakes or shifts gears, the posture of the driver and passenger is relatively fixed because of the restraint of the seat belt. Under the action of inertia force, the head and neck of drivers and passengers are overstretched, which can produce shear impact on cervical vertebrae. In addition, the driver's long-term fixed posture will cause chronic fatigue damage to the muscles and ligaments of the neck, shoulders and waist, and its early injury can be manifested as the symptoms of cervical instability such as neck and shoulders. This kind of injury can also be seen in the thoracolumbar segment, which is manifested as backache. Due to the traction stimulation of vertebral artery and cervical spinal nerve root, severe cases may have symptoms such as dizziness, headache, tinnitus, blurred vision, and even wedge-shaped compression fracture of vertebral body. In order to prevent the above situation, first of all, we should avoid driving at high speed on non-highway sections, and shift gears slowly when starting and stopping, so as to reduce the shear impact on the spine when braking and shifting gears. In addition, after work, we should adhere to the functional exercises of neck, shoulders and back, such as doing cervical vertebra exercises and broadcasting exercises, so as to reduce the chronic fatigue injury of muscles and ligaments. Once you find the above symptoms, you should go to the hospital in time.