No one ever sought to do so, he was chasing passers-by and deliberately crushed them. But also special requirements, stipulating it is the safety of the car, there was very little. Most of them belonged to the lighting devices Projecting the remaining components and assemblies of the vehicle, the designers were free to think about anything: power, speed, carrying capacity and so on. Safety in calculation were not accepted: the problem, as it did not exist. And of course, speech could not be about the complex constructive activities, designed to perform only one function: to provide security.
And really, why would the designer have to spend time and effort on the tasks, which simply to society of not standing still! The maximum speed of the first cars of the Gorky automobile plant “GAZ-a” was equal to 50 km/h. the Plant produced it in 1936. Since then it has been almost forty years. Maximum speed Lada — 145 km/h. Remember high school physics: the force of the impact increases proportionally to the square of the speed. Dramatically increasing braking distance.
It turns out, the less the speed the car is safer? Not at all. Experts believe that slow-moving car are as dangerous as excessive speed, because it creates traffic jams. This is not a paradox but a reality of the modern situation. Powerful road transport is one of the hallmarks of industrialized society. The flip side is a tribute to that measured in human lives.
Road traffic accident (RTA) is one of the disasters of the modern world; to get rid of them very difficult. Under the General objective data that characterize the situation in this region. When the intensity of road traffic, which tends to increase. Despite the fact that over 75% of the cars in the world is controlled by the drivers-Amateurs. (Here’s what matters: 83% of fatal accidents in the U.S. occurs as a result of the errors of drivers.) Despite the fact, finally, that the modern car is, in General, quite fragile structure.
In 1970, on U.S. roads 59 killed 800 people; in 1971 the roads of Germany—18 727 people. It is necessary to change those terms of which there is now traffic, not to pay terrible tribute? To reduce the amount of traffic? Impossible — it will increase. To do so was driving only professionals? Impossible. To improve the quality of the roads? It’s done, although is very expensive. To change the design of the car, in order to increase the safety of the driver and passengers? So this is now problem number one in global automobile production, including domestic.
Security requirements defined by standards and, therefore, acquire the character of law. In our country industry standards regarding safety, were initiated in 1968. Economic Commission for Europe of the United Nations to January 1, 1973, adopted 27 recommendations (rules) for construction safety, toxicity of exhaust gases, noise of cars etc. In the US since January 1, 1968, entered “Federal safety standard”. Then in this country was established under the Ministry of transport a special institution dealing only with this issue — the national authority for road safety. And since 1976 all cars produced in the U.S. must be equipped with means to protect passengers when hitting a vertical wall with a speed of 48 km/h.
Measures to improve security are divided into two groups: one increase active safety, passive. Active is a complex of technical measures to avoid the accident. This includes the vehicle’s handling, stability, braking ability, good visibility, convenient location and form controls, low noise level inside the car.
…And however the accident happened, though everything was done to prevent it. Then take effect factors of passive safety. It is also a set of technical measures designed to ensure that if the accident occurred, so at least the consequences of it would be as small as possible. What is important for this? To the middle part of the body, the one where people are, not deformed. To the doors themselves opened (this requires a suitable design of hinges and locks). To inside the cabin was surrounded by people on all sides soft padding and there were no sharp protruding objects. The material of the inner liner of the body was not garycooper (American standard 1973, the rate of combustion of this material should not exceed 101.6 mm/min). The front And rear of the car was energy intensive. This means that they have to take the full force of the blow, even in the accordion to collapse, but to prevent the force of the blow fell on the inside of the cabin and sitting in it. Below steering column was collapsible, that is not pierced upon impact the driver’s chest. There is now a single system, a single unit, projecting who the designer was not asked at the outset to make the system Assembly as safe as possible. Acquainted only with some of the latest design ideas.
Brakes. There was a time when a mechanism was set in motion brake all wheel. He had to get out of order, as the car was helpless. Because, according to many motorists, the main unit in the car is the brakes. Of course, the question itself may seem wrong — in the art no detail in the car is not the main and the lesser parts, but the fact that the safety of the vehicle greatly depends on the brakes.
Modern vehicles are equipped with a separate brake actuator on the front and rear wheels. And when a sudden emergency braking, the coefficient of adhesion of wheels with road sharply decreases, the wheel slip is included in the SW. Control is lost completely. The device, which prevents the SW, is widely developed various automotive firms. Among these devices there is an electronic one, which should cost almost more than the car as a whole. Now the machines are equipped with cheaper mechanisms. For example, “Zhiguli” is the limit of locking the rear wheel, not allowing them to enter into SW.
The activities that were discussed, refer to active safety. Now let’s talk about the passive. Padded armrests, sun visors, solid walls, locks and handles of doors, not allowing it to open on the go — to list them all is impossible But it is mostly improving the design of existing elements of the machine. And there are brand new. Bumper, for example, have always played only a decorative role. Now he is massive, behind him to fasten the shock absorbers to suppress the energy of a frontal impact. About the seat belts can not speak — they are quite widely known. Perhaps the most interesting, to attract everyone’s attention a novelty in the field of passive safety features are the airbags.
The experimental safe car
Collision, strike. The driver throws on the steering column, the passenger next to him on the windshield, rear—on the backs of the front seats, in the ceiling. It is such a shock and lead to death. And suddenly — a miracle! Hundredths of seconds are between” the time when the collision occurred and the time that the occupant thrown forward, but for that fraction of a second before people had soft pillows, filled with gas. And all the inertia of the human body came directly at them.
Well, since crashing on the soft pillow is impossible, people remained unharmed. If pillows were not, they’d all be dead or would have received serious damage. The idea, needless to say, tempting. But the implementation of it encounters a very large technical difficulties.
Sensors. Of course, it would be better if the signal hit is not given in that moment, when hitting done, and for some time before that, even for a split second. If the impact is inevitable, then let there be more time to prepare for it. Therefore, work is underway on radar, sonic, laser, infrared alarm systems. Needless to say about what a comprehensive knowledge require such development to a high level of scientific and technical development rises, the current automotive industry. The roads themselves are developing, would it be expensive system, you have to put on the car Mechanical sensors cheaper — but alas, to no signal only when the collision has already occurred.
A source of pneumatic energy can serve as a gas cylinder or gas generator such That the container is clear, the generator is a chemical or pyrotechnic specially molded composition. The container is heavy, the gas generator is dangerous, when you start the action it generates heat and toxic gases.
The drive mechanism of the system — the detonator that destroys the membrane in a cylinder or the ignition gas generating composition. The only problem is the detonator may fire accidentally.
The collector should provide almost instantaneous (0,06 seconds. at 48 km/h) the pillow filling this creates a noise like a shot, with a level of 175 dB. The noise destroyed the tympanic membrane. All attempts so far have not led to reduced noise.
The pillows are filled with nitrogen (compressed cylinder to 246 kg/cm2) or argon — rich gases, but if you can make steam, you can get burned. So many problems to be solved, and that’s not all. But it concerns a relatively narrow issue. What can we say about the complex technical challenges facing engineers attempting to create entirely safe car?
Know about the attempts to create a car in the United States, Germany, Japan, UK, Italy, France, Sweden. Here is one of the American designs (in all cases we are talking only about experimental samples). The passenger compartment placed inside a sturdy steel frame. Front and rear bumpers — solid steel bars with hydraulic shock absorbers. Upon impact with a speed of 80 km/h they get minor damage Front bumper has a stroke 760 mm, rear 335 mm.
Inside the doors — trudnosmyvaemye aluminum honeycomb. Airbags in the front hidden in the steering wheel hub and instrument panel; rear — across, connecting the middle pillar. The fuel tank separated by a fireproof partition. Controls in the recess of the instrument panel, where there is no glare. Fuel line flexible steel braid, to be able in case of accident to stretch without breaking. Brake system is equipped with electronic anti-lock device.
The other pilot safe car company “Volkswagen” — is depicted in the figure. Rear lights, direction indicators, brake lights automatically according to the brightness change the brightness of the light. The position of the steering wheel and pedals adjustable. The design of the 4 locks will keep the doors closed, even if the vehicle will tip over. Front and rear bumpers are equipped with hydraulic impact absorbers. Counting-critical device 1 determines the optimal motion mode and Lenno Shoulder straps 2 are tightened by means of pneumatic cylinders 3 when the engine is turning.
You can still tell a lot about a variety of very complex design solutions are often used by engineers in trying to ensure the safety of driver and passengers. The theme is inexhaustible, because safety is the number one problem for the global automotive industry. Indeed, the speed of the machinery for movement
on the ground are very great, as well as the engine power. Advances in technology have created a problem that mankind is now trying to solve using more technology.
Fast-growing domestic auto industry, of course, also stands apart from this main trend in recent years. In October 1972 the testing ground WE had the all-Union scientific-technical conference “ways of improving the safety design of vehicles in the ninth five-year plan”. Representatives of automobile factories, research and educational institutions of the State traffic police. All-Union Association “autoexport” and other organizations. Read among the representatives of the plants of the message has aroused the greatest interest the report of the representative of automobile plant named after Lenin Komsomol. The result of extensive work conducted by the plant together with US, the car “Moskvich-412”, produced by the plant, completely meet the requirements of the UNECE in the parameters of passive safety.
We used to hear that we live in an age of technological revolution. If you want to label the characteristic features of this revolution, talking about Cybernetics, atomic energy, space research, electronics, metallurgy, heavy-duty and swargarohini alloys, petrochemistry, polymer chemistry and so on. The car is usually in this list, as he was long, not included. Meanwhile, the automotive industry is a very dynamic, violent, very fast growing, which is the most advanced positions in the area of technology. Car, especially cars, greedily absorbs the achievements of science and technology. And it security requirements in a very large extent, forced the designers to switch to a completely different, qualitatively new level of thinking.
R. YAROV, engineer