Shock absorbers - what is it in a car? The principle of operation and features of shock absorbers

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

In the current information and automotive age, anyone knows that the ergonomics of a car are largely determined by shock absorbers. This is an indispensable part of the suspension of a modern car. How do various manufacturers of shock absorbers compete in the car market? Feedback from motorists to some extent reflect this phenomenon. After all, the picture of this competition for the consumer is very curious: American, German, Japanese companies set the tone for it. As a result, single tube shocks dominate over twin tubes.

Briefly about the modern shock absorber market

The annual Russian award "Autocomponent of the Year" allows you to determine the most successful brands in each category. So, in 2016, DEMFI became the leading brand among Russian shock absorbers, which presented struts and shock absorbers of the budget class of the Comfort series of improved quality Premium and Drive. The company's products are front and rear shock absorbers for VAZ, IZH, Lada, Ford Focus2, Renault Logan. Today, DEMFI is a small enterprise (less than 60 people work), but high-tech and knowledge-intensive, capable of expanding production, subject to proper demand.

UAZ "Hunter" shock absorbers from the Petersburg enterprise "Plaza" also deserve high praise. They are available in three versions: "standard", "sport" and "extreme". Among foreign brands, Monroe (USA/Belgium), TRW (Germany), KYB (Japan) and EGT (Lithuania) respectively won the first-fourth places.

How can a beginner-lover figure out which shock absorbers are better? After all, the world's leading manufacturers are demonstrating ever more sophisticated developments of international class. For example, only Monroe today enters the market with various brands of shock absorbers "reflex", "sensa-track", "original", "adventure", "van magnum". They currently dominate the modern car market. A sign of Monroe's high reputation is its complete set of shock absorbers, recreated directly on the assembly line of Ford, Nissan, Renault, Mitsubishi, Volvo, Porsche cars.

The German car industry uses mainly domestic shock absorbers. Reviews from motorists indicate that Opel, Mersedes, Audi traditionally use the products of the ZF concern (which owns the brands Sachs, Boge, TRW). The original shock absorber "Toyota", "Mitsubishi" is a product of the Japanese company KYB (KAYABA brand). However, this brand is becoming more and more popular in both the New and Old Worlds. The following A series are currently imported: Premium oil, Excel-G gas-oil, Gas-A-Just gas, Ultra-SR sports, AGX adjustable, Monomax off-road.

What kind of shock absorbers does Hyundai (a Korean company) put on its cars onconveyor? It is logical that from another Korean company that produces auto components. Moreover (this is a feature of Korea) both companies are run by relatives. The manufacturer of shock absorbers under the MANDO brand is called the Halla Group. Its factories operate in Korea, India, Turkey, China, Poland, USA. Tens of millions of dampers are manufactured every year. They install Ford, Peugeot, Nissan, BMW, Suzuki, Renault, GAZ MANDO shock absorbers on their conveyors. It is significant that the shock absorbers of KIA (another Korean auto corporation) are also supplied by the Halla Group.

Brand competition

Producer competition is so significant that imported brands successfully oppose local ones. In particular, some drivers prefer Japanese cars to European ones. So, according to the reviews of vehicle owners, the Renault gas-oil shock absorber manufactured by Kayaba is currently in high demand.

It is preferred for most current models of this brand: Kengo, Megan, Traffic, Premium, Master, Clio, Laguna, Magnum, etc. Its price is 30% higher than the cost of an oil device, but it is noticeably more efficient when driving on rough roads. Therefore, Renault gas-oil shock absorbers are preferred by drivers to cheaper oil ones.

Note that Renault models designed for extreme driving on good roads are equipped with special shock absorbers - Kayaba Ultra SR. After all, high-speed cornering determines a large load on such products, and howcompression and rebound. However, for everyday urban traffic, they are not optimal, because they have increased rigidity, and for imperfect roads, as you know, softer springs are needed.

However, in this article we will not be limited to reviewing the shock absorber market. Our goal is wider - to reveal the secrets of their successful exploitation. As you know, shock absorbers are the supporting elements of the suspension, respectively, imagine an ideal suspension. As you know, this element performs two tasks:

• Firstly, it connects the car wheels to the body. Thanks to it, the grip of the wheels with the road necessary for the full movement is provided.
• Secondly, it neutralizes (absorbs) vibrations that occur during movement.

Depreciation is…

A closer look at the suspension elements makes it clear that shock absorbers are damping (vibration damping) devices. At the dawn of the automotive industry (XIX - early XX century), the mentioned parts did not exist at all. At low speeds of the first cars, only springs were enough to balance the suspension. However, in the modern dynamic age of speeds, the suspension does not only contain improved springs (springs), which are now often called a somewhat abstract elastic element. This is already not enough. To illustrate the above, consider a typical case of a car overcoming a bump in the road.

At the same time, the task of the elastic element is obvious - when the wheels hit the roughness of the road, it should soften thishit. However, a modern car, when driving, has enormous kinetic energy, with the “extraordinary emissions” of which on the bumps of the road the elastic element does not cope at all instantly. Therefore, the inertia of the body causes the springs to oscillate after a collision. This is a highly undesirable effect. After all, it can lead to a resonance that can lead to a car accident (remember physics and force vectors). This happens when the oscillation of the spring from the next roughness of the road is added to its previous oscillation, which, alas, has not been extinguished. Auto engineers responded appropriately to this phenomenon by inventing a special damping device.

At the beginning of the 20th century, a damper (shock absorber) was created to dampen the vibrations of an elastic element. The idea of his work turned out to be quite simple and elegant. After the roughness of the road causes the spring to compress, its subsequent expansion and, accordingly, the vibration will be extinguished by a special device - a shock absorber. However, we will not consider it as the only part that protects against vibrations, because for the ideal behavior of the car on the road, only a shock absorber and an elastic element are not enough.

Not single shock absorbers

The shock absorbers we mentioned above are special elements to keep the suspension as horizontal and stable as possible in space. But for a truly workable suspension, this is not enough. For maximum comfort of passengers and the driver, so that the car does not count bumps, but smoothly soars along the track, it is necessary to coordinate the work of shock absorbers andother devices such as:

• Tires made of excellent rubber, providing proper grip on the track;
• non-worn springs and suspension springs (except for the functions already mentioned by us) must maintain the clearance specified in the technical specifications and keep the car at the same level;
• additional rubber-metal elements (hinges and compression buffers), damping vibrations from metal parts touching each other;
• guiding devices that determine the desired angle of rotation of the wheels.

However, be that as it may, the main damping device of a car is exactly the shock absorbers - the subject of this article. With their help, the harmony of constant contact of the wheels with the roadway is achieved (the car moves as if tied to the road), and, in principle, a truly comfortable driving becomes possible.

What does the shock absorber look like?

Outwardly, it looks like a cylindrical device attached on one side to the car frame, and on the other - to the suspension. A piston moves inside the shock absorber. This is a rod moving in a cavity filled with gas, oil or brake fluid. Due to the compression of the oil by the piston, its speed decreases. Suspension oscillations determine the oscillations of the shock absorber piston. The more actively the suspension moves (which happens on rough roads), the more resistance the shock absorber exhibits. Various shocks received when the car is driving on rough roads, as well as vibrations during heavy braking or at the beginning of the movement are damped(softened) by a shock absorber. In this case, the kinetic energy of the oscillation is converted into heat, obtained when the oil is compressed by the piston. The resulting heat is dissipated.

Depreciation process

How does the shock absorber react when the wheel hits a pothole? It compresses to dampen the shock, while its piston works in concert with the suspension springs. However, the cycle of operation of the device does not end there, since it expands, i.e., the piston extends from the shock absorber. Without it, the suspension springs would have thrown the body of the car up with the same force with which they contracted when they collided with a pothole. However, the expansion car's shock absorber piston movement is also braked by the oil.

Shock absorber design

Technically, the device during its operation converts the mechanical vibrations of the elastic element into thermal ones. Replacing shock absorbers that have exhausted their resource for effective use is a responsible matter. After all, those who installed the “new thing” immediately notice changes in the behavior of the car. Therefore, for a knowledgeable driver, the correct selection of shock absorbers is critical. And believe me, there are plenty to choose from. The car market is saturated with relevant products from famous (brand) and not so famous manufacturers. We will return to the coverage of this aspect. But first, it will be logical to digress from the principle of “whose will you be” and try to “look at the root”, that is, to understand the fundamental differences between different types of shock absorbers (A).

Judging by the design differences, then Asubdivided into one- and two-pipe. If we classify according to the type of working substance that dissipates the heat obtained after the conversion of kinematic energy, then the shock absorbers are oil, gas-oil and gas.

Two-pipe products

Which shock absorbers can be recommended for quiet, so-called family driving? Relatively inexpensive, simple in design, which do not withstand extreme sports. Double-pipe A are more inert and have a large mass. In addition, the double case cools worse. At the same time, the damping efficiency of two-pipe devices depends on the correct installation. As you know, a shock absorber, fixed strictly perpendicular to the suspension, performs its functions 100%, but if this angle increases to 50 °, then its effectiveness drops to 68%.

The design of such elements includes a working flask, inside of which a piston is located, as well as an external housing designed to store excess oil. During its working cycle, the piston passes part of the oil through its channels, and also squeezes it out through the compression valve located at the bottom of the flask. When buying products, you should pay special attention to the oil, which should not boil at temperatures below 150 ° C. At the same time, despite the favorable price, they should not be installed on cars of the latest generation.

Single tube dampers

This design is the basis for modern A. Such a shock absorber consists of a single bulb, which simultaneously acts as a working container for the piston and a housing. She may behydraulic (oil) or hydropneumatic (gas-oil). The last modification is also called combined. The principle of operation of oil A is quite simple. There is a working cylinder filled with oil (hydraulic fluid). It moves a piston with special calibrated valves, or rather with their system, which has characteristics specially selected for the suspension of a particular car model.

The dynamics of such a shock absorber is as follows:

• When valves are closed, hydraulic fluid only flows through the piston bypass. The hydraulic characteristic of the shock absorber becomes rigid.
• If the valves adjacent to compensation chamber A are opened, then its hydraulic characteristic becomes softer.

Moreover, for the shock absorber to work properly, a compression valve must pass more hydraulic fluid than a rebound check valve. Thus, with the piston valves open, the stiffness of the shock absorbers decreases.

Combination dampers

In hydropneumatic (gas-oil) shock absorbers, instead of air, compressed gas is used at a pressure of 4-20 atmospheres. Motorists call it in their own way - "gas backwater". Moreover, gas pressure is not a whim, but a way to reduce aeration (mixing air with oil), as well as an additional element of suspension elasticity. Single pipe A's do not have a bottom compression valve. The piston has full control over the resistance in both compression andlights out. They can accommodate more oil than twin-tubes of the same volume, which means they provide better damping.

Controlled and magnetic dampers

Leading manufacturers of shock absorbers are trying to solve the technical problem of adjustability of such devices in a rather original way. The American-Belgian company MONROE made special adjustment grooves on the walls of the working cylinder of single-tube A, used to adjust for a quiet or active ride. The Japanese company KYA installed a separate control valve in the lower part of the single-pipe tank A, bypassing the piston. The German concern ZF created its Opel Astra controlled shock absorber using a two-pipe gas-oil design. Two solenoid valves at the bottom of the shock absorber and in the piston are regulated by a special processor that monitors the parameters of the wheels, steering wheel, suspension.

Even more promising is the new, so-called Chevrolet magnetic shock absorber, installed last year on the Chevrolet Corvette. This is a joint promising development of the automaker and Delphi Corporation. The magnetorheological fluid used in them instead of oil is capable of changing its viscosity at a high frequency (up to 1000 times per second) under the influence of an electromagnetic field. In this case, the valve system is not used in principle: damping is carried out exclusively due to the magnetorheological effect. This design is very promising: there is no need for transverse stabilizers, it is simplifieddevice A itself, as well as impressive possibilities for controlling and controlling the stiffness of the suspension.

Compliance of the hydraulic characteristics of the shock absorber with the road topography

The design of the shock absorber must take into account various aspects of its operation. After all, poor-quality road surface determines the various modes of its operation. On the one hand, repeated small irregularities do not allow A to straighten up. In this case, a soft hydraulic characteristic is relevant. Large potholes threaten its full forced compression, which often causes damage to the shock absorber. At the same time, a rigid hydraulic characteristic of the device is in demand.

Therefore, it is pointless to ask: "Which shock absorbers are better - soft or hard?" After all, not only their softness, but also controllability becomes relevant in terms of long-term operation.

Another characteristic - the heat dissipation of the shock absorber - is important for its correct operation. After all, under conditions of a hard regime, more heat is released, and it should be removed. On the other hand, in winter, the oil in the shock absorber thickens, and its hydraulic response becomes more rigid. At the same time, the correct choice of oil becomes important for the motorist. It is undesirable to use liquids with a high content of additives, because the latter tend to soften the rubber. Most often, experts recommend using branded oils GRG-12, AFT. However, in cold weather, you should choose a liquid with a viscosity of 75Wt. For oils containing silicone, the degree of viscosity is determined inother units - cPs, which are about 10 times greater than Wt.

Diagnosis of shock absorbers

Since nothing lasts forever, shock absorbers are subject to wear and tear. This phenomenon should be diagnosed by the driver in time. As you know, the replacement of shock absorbers that have lost their proper functionality must be done immediately upon detection. Moreover, the most effective is the complex replacement A: in pairs on each axle - both on the front and on the rear. After all, it is naive to expect ideal damping after an incomplete replacement of shock absorbers.

However, this alone is also not enough. It is necessary to diagnose the whole complex of car devices involved in damping. After all, normal operation of shock absorbers is possible with serviceable rubber-metal elements (hinges and compression buffers), unworn springs and springs. Maintenance of all the above parts and mechanisms will reduce the load on the shock absorbers.

When to replace

For the driver, there are the first signs indicating the wear of the shock absorbers. Let's call them:

• increased stopping distance due to poor handling;
• decrease in comfortable speed for corner entry;
• decrease in safe hydroplaning speed (traction if there is water on top of the ice);
• worn-out A start to make sounds when the car enters a turn or overcoming bumps.

When shock absorbers break

Modern auto corporations makemore and more efficient A, bringing maximum comfort to the trip. However, if they serve the required 80 or more thousand kilometers on concrete roads, then poor-quality road surface with potholes leads to unpredictable breakdown of the mentioned devices much earlier.

Breakdowns occur most often inside the shock absorber when a car wheel hits a pothole. Oil starts to seep out of them. The shock deforms the stem, and in the soft shock absorbers the valve in the working chamber is knocked out. Such breakdowns mean the failure of A and require its unconditional replacement. Therefore, motorists weigh all the pros and cons when buying shock absorbers. At the same time, driver reviews posted on special forums should also be taken into account.

Spoil And maybe also dust and dirt that got into them. Small particles, once in the working chamber, leave scratches on the stem. As a result, the stuffing box is no longer sealed, and as a result, oil leakage occurs. Even more perfect single-pipe is A with a remote compensation chamber. Improved design allows more compressed gas and oil to be used. With an even more advanced improvement, a valve system is installed on the path of oil flowing from the main cylinder to the remote chamber, which regulates the stiffness of the shock absorber. There are modifications A, where pipes for oil flow pass over the outer surface.

Conclusion

Today's motorist is quite easy to find the right shock absorbers for his car. AtIn this case, you can use the services of both a specialized traditional and online store. For the convenience of customers, the choice of shock absorbers they need begins on the website of the online store with the indication of the car model. After this simple manipulation, the buyer sees which brands and brands of shock absorbers suit him. If he further doubts the choice between alternative brands, then numerous reviews of motorists on specialized forums and all kinds of ratings will help him form an opinion.