Is a device consisting of straps, a locking device and fastening parts that can be attached to the interior of the vehicle body or seat frame and which is designed in such a way as to reduce the risk of injury to the user in the event of a collision or sudden braking by limiting the movement of his body.
Currently, the most common belt is with a three-point fastening, which is a combination of a waist and diagonal belts. In this case, a belt is considered a belt that covers the user's body at the height of the pelvis, and a diagonal belt covers the chest diagonally from the thigh to the opposite shoulder.
On some types of vehicles, a harness type belt is used, which consists of a lap belt and shoulder straps.
The main elements of the seat belt are the buckle, the strap, the strap length adjuster, the strap height adjuster, the retractor and the locking mechanism.
Buckle - a device that allows you to quickly unfasten the belt and makes it possible to hold the user's body with the belt.
Strap - a flexible part of the belt designed to hold the user's body and transfer the load to the stationary fasteners.
The strap length adjuster may be part of the buckle, or a retractor may function.
The height adjustment device of the belt allows the position of the upper grip of the belt to be adjusted in height as desired by the user and, depending on the position of the seat, can be considered part of the belt or part of the belt anchor.
The seat belt may have retractor... A retractor is a device for partially or completely retracting a seat belt. There are several types of retractors:
- a retractor from which the webbing is fully pulled out with little force and which does not have an adjuster for the length of the extended webbing
- an automatic retractor that allows you to obtain the desired strap length and, when the buckle is closed, automatically adjusts the strap length for the user. This device has an emergency locking mechanism. The locking mechanism can have a single or multiple sensitivity, i.e. triggered by braking or sudden belt movement
- automatic retractor with pre-tensioning mechanism. The belt may have a pre-tensioning mechanism, which serves to press the belt strap against the seat in order to tension the belt at the moment of impact
The rating of a car and the demand for it in the market directly depends on what level of safety it has. At the same time, an important role in this matter is played by the main element of passive safety - the belt. Today, when creating a car, a variety of seat belts are used, which differ both in their functions and in efficiency. The history of their creation and use is very fascinating, but even more fascinating is the debate over whether belts should be used at all. All this will be discussed in today's article.
1. Who was the first to buckle up in the car?
First of all, it should be noted that a belt in a car is an element of passive safety that allows you to avoid serious injuries in the event of an accident. They are passive for the reason that neither the driver nor passengers can control them. The belts are statically fixed in the lock, thereby preventing the movement of the human body around the car. The first designs of seat belts were tested in the 19th century, but the date of birth of the first full-fledged design of such a belt is 1907. Such a belt was created in the USA. In terms of its features, the first belt was almost identical to those that are still used today. The only difference is that modern automotive belts are three-point belts, whereas the first designs were two-point.
The disadvantage of this kind of belts was that during a collision, a person could get injured from them (and even the spine could be injured). In addition, the use of two-point belts in a car does not protect either the driver or passengers from the possibility of "flying out" windshield... For the first time, the Y-shaped belt was also invented in the USA, but only in 1951. The fastener of such a belt was on the stomach, but its first versions were not perfect.
The first three-point belt with a high degree of reliability appeared in 1957 in Switzerland, and it was with such belts that Volvo cars were supplied in those years. But soon such belts also had a drawback - the lack of dynamism, in connection with which each passenger had to adjust it to their parameters.
Years of work on this issue allowed in 1970 to create the first dynamic three-point seat belt for cars. With a smooth tension, such a belt does not block movements, but with a sharp tension it very reliably holds the human body. Nevertheless, this time it was not without problems: if a person is wearing a warm sweater, such a belt did not allow saving him from injuries.
Then, in addition to seat belts, pretensioners began to be installed - special deviceswhich, after a collision, pull the passenger to the seat. This innovation really reduced the likelihood of injury during an accident. It wasn't until 1987 that the first pretensioners were used worldwide.
History of seat belts in the USSR
In the USSR, the trends with the introduction of seat belts were not so progressive. It was only at the end of the 60s that the first Western samples of this security element came to the country, from which their own copies were copied. In particular, in 1969 the 412th "Muscovites" rolled off the assembly line, on which passive safety Western sample.
It was only in 1973 that Soviet models of seat belts, which were developed by engineer L.O. Teder.As for the introduction in the country of a mandatory rule on the use of seat belts, it only came into force in 1979.
2. Purpose and varieties of car seat belts.
The main purpose of the seat belt is to prevent and reduce the degree of injury to the driver and passengers of the car at the time of an accident. After all, if, with a strong blow, a person does not hold the belt, he can get serious bruises and fractures as a result of hitting the hard parts of the car interior.
But this is not the end of the functional features of seat belts. Thanks to them also:
It is possible to prevent the possibility of injury from the deployment of the airbag. The strap keeps the passenger in one correct positionin which an airbag can really save;
During a collision, the passenger remains inside the car, although the force of the impact can throw him out and further injure;
The difference between the speed of movement of the body and the car is reduced, thereby reducing the likelihood of injury.
Types of car belts
Over a long history of existence, seat belts have undergone many modifications, which is why today you can find a large number different types these elements of the car. In particular, according to the type of fastening, there are:
1. Two-point waist belts.
They are attached only in the waist area and are characteristic mainly only of old types of cars. For more modern cars these belts are only fitted to the rear passenger seats. Today, point-to-point belts are only fitted to the seats of buses and aircraft. They are not used in cars for the reason that with a strong impact they are able to separate the lumbar vertebrae.
2. Three-point diagonal-waist belts. They represent a single belt strip, which is attached at three points at once, which prevents the spread of energy from the impact to the body of the passenger and driver. Their difference is that they attach not only the lumbar part to the seat back, but also the shoulder part.
3. Four-point belts for sports cars.
4. Five-point - for sports cars and child seats. Such belts also have a "knee" section that is attached to the passenger's belt between the legs. These belts also have two shoulder straps.
5. Six-point - for sports car models. They have a strong resemblance to the previous type, but differ in an additional belt that passes between the legs. According to experts, such a solution does not significantly increase passenger safety.
6. Seven-point belts, which are only used on sports aircraft.
Through various experiments, other types of seat belts have been invented. But all of them, for one reason or another, were not put into mass production:
- crosswise belt - in case of a strong impact, a “spacer” remains on the passenger's chest;
- 3 + 2 - a belt that connects three- and two-point seat belts at once, helps to protect against injuries in a side collision or rollover. Not used for the same reason as a criss-cross belt;
Four-point in the form of suspenders - has proven itself poorly due to the fact that its base is attached not to the car body, but to the seat.
3. Why use an airbag if you already have a seat belt?
It should be understood that in any accident, there are three hits to the car at once:
1. A blow that hits the car body directly.
2. Impact that is transmitted from the body to the human body, as a result of which it hits the interior of the passenger compartment.
3. A shock that occurs inside the human body when internal organs hit each other and the skeleton.
Fortunately, it is thanks to the design of the car and such safety elements as belts and airbags that it is possible to soften the impact that falls on the human body. In particular, modern cars are able to literally converge "in an accordion", leaving the driver and passengers intact. Of course, after a strong blow, restore vehicle it will be very difficult, but at the same time the accident can do without casualties.
In such a situation, the only question arises: why then airbags, if the people in the car are also protected by seat belts? Everything is not so simple, because even with a belt, there is a possibility of a strong collision between the human body and the cabin body. Often, the belts simply break, the force of the impact pulls out their locks, and the person still hits the front body of the cabin. In addition, even belts can cause injury if struck hard.
However, if in such a situation the airbags are deployed on time and correctly, injuries, in principle, will not threaten a person. However, airbags cannot act as a single element of passenger and driver safety. After all, what is the use of them if after the impact the passenger was literally thrown out of the car? Thus, belts and airbags must necessarily work in tandem.
4. Are there situations when a seat belt is not needed?
Oddly enough, there are many situations in which even experts recommend neglecting the use of seat belts. These situations include the following:
- movement on ice or ice crossing. Since in such a situation there is a risk of falling under the ice, it is better not only to forget about the belt (it will definitely drag you under the water along with the car), but even open the door so that in case of danger you can quickly jump out of the passenger compartment;
When driving on pontoon bridges that are not very durable. The explanation here is the same as in the previous paragraph;
When the vehicle is traveling at low speed in low visibility conditions. This may be a situation where the ground is covered with very dense fog or smoke. In this case, you also need to be on the lookout and do everything possible to get out of the car very easily and quickly;
When the driver has practically no opportunity to maneuver on the road, and he again moves at a very low speed.
5. Myths about seat belts and the benefits of using them.
Despite the fact that we have listed a number of situations above in which it is really worth refusing to use a seat belt, many drivers disdain it for other reasons. Unfortunately, there are a number of myths among motorists that car belts do more harm than good. Let's try to debunk them:
1.
Belts only bring discomfort. If you are accustomed to constantly driving without a belt, then, wearing a seat belt, you can really feel discomfort. However, if you were taught to fasten your seat belt from childhood, then you will be uncomfortable without a seat belt in the car.
2. If there is an airbag, no belt is needed. We have debunked this myth a little higher. Don't forget that without a strap, the pillow can also deliver a powerful blow.
3. If the car catches on fire, the seat belt will prevent you from getting out of the passenger compartment. It does happen. However, if there is no belt, then the person is unlikely to have the strength to get out of the car, since injuries resulting from an accident can make him immobile. But if it remains intact, rescuers or even bystanders can pull it out of the burning car.
4. During a collision, it is much better to be thrown out of the car than to remain strapped on. Of course, there are times when a person is thrown out of the car, and at the same time he remains unharmed. But in 3 cases out of 4 such people are injured even more than if they stayed in the cabin. Moreover, if the belt did not protect passengers from hitting the windshield, they could receive not only head injuries, but also break the spine.
5.
Belts can cause permanent injury. In some cases, people can actually get injured in the cervical spine. However, for this, the impact force must be so great that without a belt, a person would be injured many times more serious. Thus, the degree of injury with the belt should be considered less significant.
6. At low speeds, the belt is not required. Practice shows that even if a car moves at a speed of some 30 km / h and at the same time collides with an obstacle weighing up to 1 ton, its injuries will still be serious. But if in such a situation a seat belt is used, only the car will suffer. It is especially important to be strapped in if the collision occurred at an angle. It is also worth noting that collisions often occur at a relatively low speed - up to 65 km / h.
7. When traveling a short distance, you do not need to buckle up. Surprisingly, but, according to statistics, 75% of accidents occur at a distance of up to 40 km from the parking lot. That is, even if you went to the store, you still run the risk of getting into an accident, which makes mandatory use seat belt.
8.
On back seat no need to buckle up. Do not forget that even in the fastened state you can get injured, so even in the back seat it is still better to use the seat belts. In some cases, passengers in the back seat are very seriously injured, since they can also be thrown into the front window from the impact.
9. Belts are an obstacle to getting out of the car through the window. It often happens that the driver begins to realize the likelihood of an accident while driving. According to some motorists, if he is not fastened at this moment, he will have the opportunity to jump out of the car. Unfortunately, in such situations, drivers receive much more serious injuries than if they remained in place with their seat belts.
10. The belts do not allow free movement inside the passenger compartment. If it was only about the old-style belts, then it really would be impossible to raise an argument. However, modern seat belts provide absolute freedom of movement that drivers and passengers carry out smoothly. They work only when a person makes very sharp movements.
11. If an adult is wearing a seat belt, he cannot hold the child in his arms while riding. In fact, it is very dangerous to practice this, because even at a speed of 30 km / h, a 7-kilogram child will survive the impact force of 135 kg and easily fly out of an adult's hands.
12.
Seat belts are not life-saving. Indeed, belts often save from injury rather than death. Keep in mind, however, that accident injuries are often fatal, although they could have been avoided with a belt.
13. Sitting behind the driver is as safe as possible, so you don't have to wear a seat belt. Practice does not support this statement. According to experts, the safest place is in the back in the middle, however, even sitting on it, a person is likely to fly out through the windshield.
Having listed the most common myths about seat belts, we can only conclude one thing: maybe this belt will not be able to protect you from injury, but still, over the entire period of the existence of cars, such a simple device helped save the lives of more than one person. Try to become such a person in the event of an accident. In addition, do not forget about the fines that the driver and passengers will have to pay for driving without a seat belt.
Categories of automotive security systems.
Automotive security systems fall into two categories: active and passive... As active security systems absolutely all automotive qualities are used, which reduce the likelihood of an accident (road traffic accident). First of all, these are mechanisms and machine control units. More precisely, this is what is under the control of the motorist, namely the brake, various auxiliary devices and steering.
Passive system safety is a set of elements that reduce the consequences of an accident that has already occurred. It includes special seats, bumpers that absorb the impulse from an impact, all kinds of belts and airbags. This system does not directly depend on the driver's behavior.
Traditional element passive system - seat belts invented over a century ago. Seat belt device very simple, but belts are considered one of the most effective means auto safety. Seat belts prevent the body from jerking forward during a sudden stop.
Background.
The very first seat belts were introduced into a car only at the beginning of the 20th century, and according to known data, a patent for them was first issued in 1907 in the United States, however, attempts were made to create such inventions before. Although the operating principle of seat belts has hardly changed over the past hundred years, but appearance and the shape has undergone great changes, and the level of reliability has become an order of magnitude higher.
Initially, seat belts in cars were no different from those used on airplanes. There were two fixation points on the sides that covered the torso at waist level. However on high speeds, the belt not only did not help, but itself was the cause of serious injuries to the internal organs and the abdominal cavity. Therefore, no one argued about the need for its modernization.
As the power of the engines and the speed of cars increased, as well as the number of cars on the roads, the issue of safety became more and more important. 1951 was a watershed in road safety. This year, a new belt shape was adopted, in the form of a Y-shaped belt with a zipper on the belly. But, despite the innovations, injuries from the belt itself were still not uncommon.
A tipping point in security development.
The familiar modern car seat belts with three retention points appeared in the second half of the 50s. In 1957, Niels Bohlin, an aeronautical engineer from Sweden, redesigned the seat belts by adding a third anchor point. Now the loads on the body during collisions were distributed evenly. The first company to start serial production of cars with such belts was "Volvo". It happened in 1959. Volvo cars are still considered the standard of safety and reliability.
Since that time, belts have become increasingly popular. They have become more reliable, and the convenience of their use has grown significantly. But gaining popularity, there were noticeable new design flaws. Due to the fact that the belt was static, i.e. was pre-adjusted to fit the size of a person, then during collisions there was often a "diving" under the belt. Inertial belts, which appeared in the 1970s, have successfully dealt with this problem.
The principle of the inertial mechanism is to slowly pull the belt to the desired length, while the passenger is not constrained in his movements. A sharp pull of the belt is blocked by a retainer, which helps out in accidents. However, there is one caveat, if the passenger is wearing thick clothes, for example a down jacket, then the inertial system is very ineffective and can even cause injury, since there is enough space between the belt and the body.
Later, one improvement was introduced, namely the pretensioners. The pretensioners worked in a collision, and as their name implies, they pressed the strapped passenger tightly against the back of the seat, reducing the distance between the body and the belts. They came into action with electric drive, or disposable squib.
The Soviet Union, along with other countries, also conducted its own developments in the field automotive safety... Especially distinguished the Estonian SSR, in which tests and research in this area were actively carried out. Since the 1970s, the production of car seat belts, which were produced in the Estonian association "Norma", began. Since 1979, it has become mandatory to use seat belts for those sitting in the rear seats, and they might not have fastened them.
Security measures in our time.
In the modern world, many motorists and passengers refuse to buckle up for various reasons. If you give the average statistical data, then every second person refuses to use belts. Some people think that this will definitely not happen to them, others argue that belts are more harm than good, especially if you need to quickly leave a wrecked car. However, the bitter experience of road accidents, as well as numerous studies refute these concerns. But, despite this, society has two positions on the problem of using seat belts.
In the end, experts advise using seat belts, since it is better to get off with bruises than a head punched into the windshield. If the driver is wearing a seatbelt, then in most cases, he retains control over the car, which largely helps to reduce the consequences of an accident.
Most US states have mandatory rule - passengers on front seat must be wearing a seat belt, otherwise a fine of several hundred euros. In Russia, there are similar obligations to the participants road traffichowever, due to the low fines, few adhere to these rules.
There are special settings when transporting children. Since the child's head is disproportionately large, and the cervical vertebrae, on the contrary, are very fragile, then children should be transported to special seats, which provide for all the features of their physiology.
Finally.
As we can observe, the designers to this day are faced with the issue of safety while driving. The past decades have laid a kind of foundation, but since the capacities of cars of the last century and the current one are incomparable, it has to be constantly refined and new solutions introduced. The largest automakers test all their new products in crash tests, spend millions of dollars on finalizing all kinds of car components. The car today is a fairly reliable and technological tool, although not without flaws.
Now cars are equipped with a significant number of safety systems and means. They are aimed at preventing loss of control on the car during emergency situations ( active systems) and the maximum possible reduction of injury to passengers in an accident (passive means).
It all started with seat belts that "migrated" to vehicles from aviation. The first prototypes of belts appeared almost at the beginning of the automotive era itself. In 1903, the first version of such a security system for cars was proposed, but then it did not take root. They became more actively interested in them in the 50s of the last century. Moreover, at first, belts were offered only as an option and only a little later as standard equipment.
It is worth noting that at one time the designers tried to replace the belts with another system - airbags. But later it turned out that from self-use pillows are of little use, but in combination with belts, they seriously increase safety.
In general, seat belts are one of the “oldest”, but effective means of preventing injury, that is, they belong to the passive system.
WHAT IS A SEAT BELT CONSISTS OF
The main construction of the seat belt consists of:
- straps;
- castle;
- mounting bolts;
- retractor.
For the production of straps, synthetic material is most often used. The main requirement for it is a high level of strength. The belt retractor is a ratchet mechanism. Emergency blocking occurs due to the sensitive element.
The sensing element is based on a simple metal ball. When it moves, the coil is locked by a system of levers. Some designs use a pendulum instead of a ball.
Separately, it is necessary to talk about the system responsible for the gradual belt tension. This is due to the flywheel. It is mounted on the spool axis. It is a small disc that makes the process smooth. But if an accident occurs, a jerk is formed, due to which the disk has to overcome the frictional force. In parallel, pressure arises on the helical surface.
Attention! As a result of the actions described above, the disc is displaced and the ratchet is locked.
The seat belt device helps to ensure the safety of passengers during collisions. But even they have a certain efficiency limit. At speeds over 200 kilometers per hour, belts are of little use.
The bolts in the seat belt device are responsible for the reliable fastening of the entire structure while driving. They are made of solid carbide that can withstand heavy loads. Moreover, they are attached to the car frame to ensure maximum reliability.
Do seat belts save you?
“There is nothing more horrible than the fate of a driver who was not wearing a seat belt at the time of the road accident. This is how events unfold when the driver at a speed of 80 km / h hits a fixed obstacle.
The bumper is pressed in 0.026 seconds after the impact; a force thirty times the weight of the car stops it moving in the front seat line, while its passengers - if they are not wearing their seat belts - continue to move inside the car at 80 km / h.
After 0.039 seconds, the driver, together with the seat, is rapidly moving forward 15 centimeters.
After 0.044 seconds, he breaks the steering wheel with his chest.
After 0.050 seconds, the speed drops so much that a gravity force 80 times its own weight begins to act on the car and all passengers.
After 0.068 seconds, the driver hits the instrument panel with a force of 9 tons.
After 0.092 seconds, the driver and the passenger sitting next to him simultaneously bump their heads into the front windshield car and suffer fatal skull injuries.
After 0.100 seconds, the driver hanging on the steering wheel is thrown back; he's already dead.
After 0.110 seconds, the car starts to roll back slightly.
After 0.113 seconds, the passenger sitting behind the driver - if he is also not fastened - is in the same line with him, strikes him again, and at the same time gets fatal injuries.
After 0.150 seconds, there is complete silence; shards of glass and iron fragments fall to the ground. A cloud of dust envelops the collision site. It all happened in less than two tenths of a second. "
Each time we reread these lines from the book “La Mort Inutile” by the famous French traffic safety expert Christian Gerondeau, we catch ourselves thinking that this nightmare can be completely avoided if we use a primitive, in essence, device - a seat belt ... The idea of \u200b\u200bsuch belts is far from new. The first patent for such a device was issued in the United States back in 1885. 15 years later, the belts were tested on one of the airplanes of the American Air Force. In the Old World, designers also worked to solve this problem. In 1909, a unique device was created in England, which consisted of a large diameter coil spring and straps. The purpose of the device is to keep the passenger on car seat... In the early 20s, they began to equip with seat belts racing cars... It seemed that there was only one step left before their widespread distribution, because much of what was beginning to be used on sports cars, soon appeared on serial. The seat belts were not affected. To migrate to production cars, it took them as many as three decades, because only in the 50s they began to be equipped with individual models cars from America and Sweden. 
Types of seat belts in the car
Car seat belts by type of fastening are:
- two-point;
- three-point;
- four-point.
For racing cars Reinforced five- and six-point belts have been developed, but they have not yet found application in production vehicles due to installation difficulties.
There is also a division of seat belts according to the principles of operation. The following types are distinguished:
- static;
- dynamic;
- leading.
Pros and cons of different seat belts
Two-point seat belts can still be found in the backseat of some cars. They were equipped with outdated russian models machines. There are both waist and shoulder versions of such belts.
The lap belts look like safety belts in aircraft seats. They do not impede movement, but can cause severe spinal injuries and even lead to paralysis.
Shoulders are fastened diagonally. The top point is located on the center pillar of the side of the passenger compartment. The lower one is a lock installed between the passenger and driver's seats. This type of belts is not reliable enough, as a person can "emerge" from it in an accident.
Three-point seat belts are installed on almost all modern cars. The V-shaped diagonal waist design evenly distributes inertial energy between the torso.
Four point belts safety are equipped with sports car models, the seats of which have four attachment points. Together with five- and six-point, they represent the group of the most reliable seat belts, but cannot be installed on ordinary cars due to design features.
Static seat belts not installed on modern models cars. The wide strap that forms the basis of such a belt is a piece of synthetic tape of a certain length, which is manually adjusted. This design does not meet modern safety requirements.
Dynamic seat belts equipped with a special mechanism that lengthens them evenly or winds them up with smooth movements of the passenger. With a sharp jerk, the belt is fixed, due to which the human body is tightly held in the seat.
Mechanism leading belts is closely connected and works in conjunction with all other safety systems of the machine. The electronics in the car, based on the readings of the sensors, pre-tightens the safety belts and reliably fixes them in the event of dangerous situations. If the machine successfully passes the hazard, the belts return to normal operation. This most advanced and reliable mechanism is used to equip the most modern cars.
Components and their purpose
Note that not all components may be included in the design of safety equipment on certain models.
Fasteners
Let's start with the attachment points. They are often installed on body elements. This is due to the fact that the human body at the moment of inertial displacement forward creates a significant load on the belt. In the case of using an attachment point mounted in the seat, the structure may not be able to withstand due to the heavy load, and the backrest will move along with the body. In the case of attachment to the body, this will not happen.
But in devices with four or more points, some of them are still mounted in the seat (vertical straps). At the same time, we note that the design of seats in sports cars is much more rigid and designed to withstand heavy loads, therefore, it is allowed to install mountings in them. But as for the fastening of the lumbar strap, it is fixed to the body.
Now about the convenience of the attachment points (applies to the upper). Seat belts are comfortable as they extend over the shoulders. Dots on the counter, however, can cause discomfort. With its high position in people of short stature, the diagonal part of the belt will pass almost along the neck, which is not only inconvenient, but also unsafe. And for tall people, the low position of the top point will allow the belt to pass below the shoulder, which will restrict hand movement. Therefore, manufacturers make the upper attachment points on the racks adjustable. Adjustment is not required on fasteners located on the seats.
Lock
The lock provides a detachable attachment point. It provides the convenience of laying the straps. The operation of the lock is very simple - a hole is made on the tongue located on the belt, and a pin is used in the lock. When installing the tongue, the pin goes into the hole, thereby ensuring reliable fixation. To disconnect, you just need to press the special lock button to retract the pin and release the tongue.
Inertial coils
The effectiveness of the belts depends a lot on the correct tension. Previously, for this it was necessary to adjust the length of the straps "for yourself" with special loops. This did not particularly cause problems for the driver, since he only had to adjust the belt once. But passengers with different builds had to adjust each time.
Retractable coil mechanism
This problem disappeared with the advent of inertial coils. It provided automatic winding of the tape so that it did not interfere. Pulling it back can only be done with a smooth movement. It is not possible to quickly unwind the strap with such a reel, since the mechanism blocks it when it unwinds quickly.
The use of an inertial coil solved several problems at once - when unfastened, the tape unwinds itself, which is very convenient. Also, the coil independently adjusts the tension by choosing the excess part of the belt. Another positive quality - blocking of the spool during sudden unwinding. It does not allow the belt to unwind, so it "catches" the body, not allowing it to go forward strongly. But there is also a negative quality - it does not block immediately, and the length of the belt still increases slightly, because of which the body manages to gain a slight acceleration. This increases the likelihood of injury.
Limiters
Stoppers allow you to lengthen the strap slightly, but smoothly. The bottom line is that the body experiences significant overloads during inertial deflection. If it is stopped abruptly, which is what the belt does, injury is possible. But if the strap slightly increases its length, then this will partially extinguish energy and increase injury safety.
Torsion coil
The limiter is a torsion bar that acts as an axle for the coil. In the event of a collision, the reel blocks the unwinding of the belt, the body rests against the belt, which creates a load on the belt. When a certain effort is reached on the strap, the torsion bar begins to twist, turning the reel and unwinding the strap. Because of this, there is a smooth damping of the belt force. It is worth noting that the strap itself does the same. The polyester tape may stretch slightly if it is heavily stressed.
Pretensioners
Pretensioners have appeared on cars quite recently, but their role is significant. As already noted, the coil does not lock immediately, so the body still gets accelerated. To prevent this, pretensioners are used, which tighten the belt even before the body begins to inertial movement. That is, it prevents acceleration from being received. These devices work proactively and for this they use impact sensors used in the design of airbags.
Pretensioners work as follows: at the moment of impact in a collision, sensors register it and send a signal to the control unit. That, in turn, activates the actuators, and they instantly pull the tape, excluding even the slightest displacement of the body forward. There are two types of pretensioners - pyrotechnical and electric.
If the seat belt does not function in the car, it is necessary to urgently eliminate the cause of the breakdown, since it is dangerous to drive with faulty or problem belts, this is contrary to traffic rules.
1 The main causes of malfunctioning inertia belts
Among the common breakdowns that occur during the operation of seat belts and the mechanisms that control their work, the following can be distinguished:
- belt jamming when trying to buckle, even in the case of a smooth pull;
- belts do not stretch due to frost or wear of the roller mechanism;
- belts do not retract when unfastened;
- the coil lock is broken or the main mechanism is damaged.
Of course, there are other problems, but they are less common, which means that the risk of encountering such a breakdown in your car is minimal. Many people believe that in case of some breakdowns, it is possible to drive with faulty beltsbut, according to traffic regulations, if the vehicle is operated with a faulty seat belt mechanism, an administrative fine may be imposed on the driver
In addition, the car manufacturer is not responsible for a traffic accident, even if the car is on warranty service in case the owner did not turn to specialists about the replacement of seat belts. Therefore, before you repair belts with your own hands, you must understand that all changes are made, as they say, at your own peril and risk.
Most often, the owners decide on an independent repair due to the very expensive service... For example, changing the belt mechanism or complete replacement belts on standard passenger car the middle class will cost the owner at least 15 thousand rubles. Not everyone is willing to pay that kind of money, especially when it comes to a simple breakdown, for example, the need to lubricate or replace the gear of the main mechanism.
2 The principle of operation of the mechanism and tools for repair
In each modern car they work on a fairly simple principle - a coil with a blocker based on a gear mechanism, with the help of which the coil rotates. The gear mechanism itself is closed by a small pendulum with a ball or spheroidal support with a system of levers. When the belt is pulled out smoothly, the support rotates with the spool gear, and with a sharp jerk, the flywheel is blocked. In this blocking system, most often there is a malfunction.
Thus, in order to repair the coil and other mechanisms, it is necessary to remove it, for which almost all cars will need to remove the trim, and on some models the seats on the side with which the belt is not working properly. To remove and self repair you need tools which should include:
- a set of flat and Phillips screwdrivers;
- a set of spanners of various diameters;
- lubricant, wire, napkins and material to protect seats and upholstery.
Depending on the complexity of the repair (sometimes a complete replacement of the coil is required), other additional tools may be required for work. Do-it-yourself repairs at a VAZ are much easier, especially on older versions, since these cars do not have side airbags, the trim is easily removed and installed, and there is no need to remove the seats.
3 DIY seat belt reel repair
Regardless of the car model, in order to get to the mechanisms that are responsible for correct work seat belts, you must remove the plastic lining of the side panel. On almost all models, it is held either on clips at the top and bottom, or on bolts of various diameters. To access the lining, it is necessary to move the seat as far forward as possible, or remove it according to the instructions (unscrew several front and rear mounting bolts and remove the seat from the slide).
To comply with safety precautions, especially for cars with side airbags, before starting work with the belt reel, it is necessary to remove the negative terminal from the battery and, if possible, the contacts to the airbags (you can see it by the color of the wires in the car's wiring diagram). This must be done so that the igniter does not trigger, which can lead to injury. The coil is usually closed with a plastic case with the inscription "Do not open", but in order to eliminate the cause of the breakdown, it must still be opened. This plastic cover is fastened with several bolts to the rack.
If the seat belt does not retract well, then the spring of the return mechanism may simply fly off or the spring is damaged. If it's a spring, you can replace it. At the replacement stage, you should be careful, since it is not difficult to remove the spring mechanism, and installing it back on the coil is quite problematic. There is no specific installation scheme, it all depends on the model and complexity of the mechanism.
One more common reason, in which the belt does not retract back, is the wear of the metal tensioner belt or the breakage of the steel angle, which feeds the belt into the hole on the shaft. Because of this breakage, the shaft rotates idle, that is, it does not wind the tape around itself. If the corner does not break off much, you can bend the tape with pliers and correct its position by bending the tip a little closer than intended.
4 Further inspection and elimination of simple breakdowns
Upon further inspection, you will find that the plastic shaft is connected to the metal stem that extends from the coil. In one part of the shaft there is a hole for mounting on the stem, on the other side there is a small hole that looks like an eyelet on a regular needle. To twist the shaft and assemble the entire mechanism into place, a piece of metal wire or a thin knitting needle must be threaded into this very eyelet. The shaft turns counterclockwise until it stops, support the mechanism with a screwdriver and a wrench.
Now you can wind the belt around the shaft and remove the wire, this way the two halves of the mechanism will connect and the cover will snap into place.
There are other causes of failure when the belt does not retract or extend, some of which can be resolved without replacing the spring or major parts. For example, on many VAZ models, especially the tenth family, due to the mechanism begins to jam in frosty weather. Most often, this is not caused by breakage, but by thickening of the grease, which is not resistant to subzero temperatures. When disassembling the coil, it is necessary to additionally lubricate the mechanism with frost-resistant grease such as Litola or silicone.
Sometimes, for better stretching and retraction of the belt, it is enough to reduce the bending angle of the metal "tab", which is acted upon by the ball mechanism. If the reel is vertical, the retainer should not cling to the gear teeth, but should only be triggered when the tape reel is tilted. In case of more serious malfunctions, it is recommended to replace the coil with a new one from the same car model.
