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To understand why you need a shock, - try to ride without it:

To the car did not take all the bumps in the road, the suspension of the machine be sure to use a resilient member. Usually primenyatesya spring. In addition to the spring, a spring can be used, but it is full of archaic. Other alternatives spring - air suspension "Citroen" or gidropnevmopodveska "Rover", which run on compressed gas. But back to the spring. When driving on the road the car starts to wobble, and this is unacceptable. The main task of the shock absorber and is to suppress these oscillations, or damp.

All dampers operate on this principle: the shock absorber is located inside the cylinder with the piston rod ,, who "walks" in oil. Oil spills at the damper piston through the hole. This creates the necessary resistance to the movement of the stem. Also in the damper must be a container (compensator chamber) with compressed gas (air or nitrogen). Inside the shock absorber, and a piston displaces the excess fluid, causing the compressed gas.

When the gas is air, this is called a hydraulic shock absorber ("Soviet" shock absorbers "SAAZ"). Lack of air that it is under constant shaking "foams oil", and at a strong shaking may occur bubbles of low pressure, which greatly reduces the effectiveness of the shock absorber.

It is often used instead of air nitrogen. Sometimes it is injected at a low pressure of several atmospheres. Such shock absorbers called gazonapolennnymi low pressure. However, under low nitrogen pressure does not solve the problem of a radical "foaming oil" and cavitation (i.e., bubbles formation of low pressure).

The solution was found when a French engineer De Carbon uploaded to the camera compensatory nitrogen pressure of more than 20 atmospheres and nitrogen separated from the oil-piston seal, which prevents nitrogen and oil into contact with each other. It removed the problem of oil foaming and cavitation. Nitrogen under high pressure allows the piston valves operate silently and quickly and creates additional stress on the stock. These shock absorbers are working efficiently and accurately.

Gas-filled shock absorbers are not recommended for use on small machines, as additional force on a body exerted such shocks, bad for the "crumbs".

Recently there have been new developments. For example, the firm "Koni" makes shock absorbers with adjustable stiffness. The most "fancy" allows you to do this directly from the cabin. Such a "slope" is placed on the car Maserati. In turn, the firm "BOGE" has developed a system of automatic leveling (the system "Nivomat"). Its meaning is that when the vehicle is loaded, it "sags" and it varies clearance (clearance). Once the vehicle is loaded, the vibrations of the wheels when driving is actuated pump integrated into the design of the shock absorber. This pump after a few hundred meters restores proper ground clearance. After unloading the car the pump is automatically adjusted to the value of the old ride.

Shock - it's the part of the car, which did not think about it until the moment until it breaks. As soon as the shock absorber "covered", we realize how bad without it, and how to use it well.

Car with broken shock absorbers after driving any tuber starts to sway dangerously, you can even hook belly asphalt. It may shock and jam, then the machine turns into a "stool." If this happens, then the baby is clear - the shock absorbers should be changed or repaired.

But usually the shock absorbers wear slowly and the driver does not notice. According to Western experts, in Europe about 30% of cars older than 5 years, go with broken shock absorbers. And what is done in the CIS countries with our roads - do not know.

But shocks affect not only comfort, but also on safety. It is appropriate to bring the results of the independent research organization "Tuv Rheinland", which carried out the examination on the effect of the shock absorber on driving safety.

When braking at a speed of 50 km / h on a dry road with a single shock, worn by 50%, the braking distance of a vehicle is increased by two meters. A lot or a little - to judge you. But how often is the two meters and not enough to avoid the tragedy.

When a car with worn shock absorbers 50% enters the pool of water in a layer of 6 mm, the effect of hydroplaning (when the machine is "pops" over the coating and becomes unmanageable) occurs at a speed of 81 km / h. Under normal shock absorbers this speed was 85 km / h. In addition to the above, "killed" shock absorbers increase the risk of drift car in sharp bends. Also worn shock absorbers incapacitate many parts of the car, tires, springs, suspension wheels, ball bearings, etc.

Most motorists are thinking about replacing the damper only when the oil flows out of him: "Stand flowed - will have to be replaced somehow." But this is the last stage of life (or rather death already!) Shock absorber. Until this state to bring the car is not recommended. And to check the suspension, not have to go on a special stand. We only need to "prozhat" every corner of the car and, if after pitching will be more than one complete oscillation, it means that shock "will not stand." They need to be replaced.

Manufacturers recommend to check the condition of the shock absorber after every 20 thousand kilometers of the car.

So you've decided to replace the shock absorbers. But how to choose? Remember that shock largely determine the nature of the drivability. Replacement of the shock absorber can be converted into a sports soft suspension. If you're at high speeds, for example, in the "eight", annoys excessive buildup of body, our advice: buy sporting character absorbers (Koni, Bistein, etc.), but be aware that the suspension may be tough, and will detail the profile of the road passed sitting in the cabin.

"Soviet" shock, of course, cheaper overseas. And the owners of "our" cars can choose. You can buy GaAs, and you can buy products of foreign companies.

The owners of cars the choice is between "native" shock absorbers, which are those that are delivered directly to the assembly line factory, and production companies operating in the secondary market. There are shock absorbers especially for used cars. Such products are usually much cheaper than the "native" and the quality and performance of such products as good and sometimes better than the factory.

But the replacement shock absorbers not such a simple matter. There are many subtleties and tricks. And so many companies give a guarantee only when properly installed in the service centers.

Now safeguards. The normal warranty of the city shall be 1 year, regardless of mileage. We would recommend to buy shock absorbers in retail stores rather than in the markets. In the markets, of course, cheaper, but then the rack can be changed every six months. As they say, avaricious pays twice.

We give a description of the major manufacturers of shock absorbers, whose products can be purchased.

SACHS - a European leader in the supply shock on the conveyor. It is standard on the BMW, Audi and others.

BOGE - makes hydraulic and gas shock absorbers. Available at BMW, Saab, Volvo.

MONROE - ranked first in Europe to implement the shock absorbers on the secondary market. It produces gadravlicheskie and gas-filled shock absorbers low pressure. Available at Volvo.

GABRIEL - US firm. Second place in Europe for sales in the secondary market. It produces gadravlicheskie and gas shock absorbers.

KAYAVA - Japanese firm. The products are delivered to many conveyors Japanese automakers. Available as shock absorbers for vehicles manufactured in Europe.

DE CARBON - French company, has released the first high pressure gas shock absorbers suspension Mc Ferson.

BILSTEIN - sport shock absorbers. Available at some German cars, for example, Mersedes-Benz.

KONI - Dutch elite shock. Available at Ferrari, Porshe. They are used in the "Formula 1" racing Indy. Shock absorbers of this brand are also used in front-vases.

Shock absorbers on a design are divided into two main types: two-pipe and monotube shock absorbers.

Monotube shock absorber

1. Atmospheric pressure.

2. The valve regulating the compression resistance.

3. The valve regulating the tensile strength.

4. Relief valve.

A two-tube shock absorber

1. Atmospheric pressure.

2. Back-up camera.

3. Basic Single-pipe system.

Damper - extra weight that provides springiness and muffles vehicle fluctuations. Assimilates vibrations damper main system, ie, the main system ceases to vibrate - movement is limited vibration damper. Dampers minimize body movement. As the damper element may be used; as a liquid - (oleo) and gas (gas shock).

Monotube shock absorber is characterized by high reliability, low sensitivity to overload, uncritical to the installation location. The disadvantages include the degree of damping of the compression parameters (which in the latest developments compensate for the installation of additional safety valves in the piston) and the fact that single-tube shock absorber is a shock absorber Length type.

A two-tube shock absorber technology known as atmospheric, operating at low pressure type of a double pipe.

Advantages: insensitive to external damage. Here, in contrast to the monotube dampers, mechanical effects may be taken and the outer tube, adjusted the position of the machine is limited to the area of the body structure. This is a short type of shock absorber, because the camera is the balance of the working cylinder.

Disadvantages: sensitive to shock overload (dampening stops). There are only certain provisions of the installation, the accuracy of matching Precision pipe diameters.

Damping characteristics are the result of the total function of damping holes and a spring loaded valve that closes the channel; spring responds to pressure by increasing the aperture exit hole free. The opening of the piston and the spring can be specifically adapted to provide linear damping function and softness. The internal control mechanism is used to get more performance for a single shock absorber. The values of the degree of compression - often only 30 ... 50% of the capacity output.

Shock absorbers with electronically adjustable feature (active processing) are used to extend the range of motion and increase comfort, safety. Damping Control parameters, on the other hand, it leads to the establishment of communication between comfort and safety.