Types and purpose of car suspension. Car suspension - everything car owners need to know about it What is the name of the front rear

Let's go straight to the topic without shelving. . Moreover, the topics are quite interesting, although this is the second in a row about cars. I'm afraid the female readers and pedestrians don't quite like it, but that's how it happened Listening to the topic from :

“How does car suspension work? Suspension types? What determines the rigidity of the machine? What is "hard, soft, elastic ..." suspension "

We tell ... about some options (and oh, how many of them actually turn out to be!)

The suspension carries out an elastic connection of the body or frame of the car with the axles or directly with the wheels, softening shocks and shocks that occur when the wheels hit the bumps in the road. In this article, we will try to consider the most popular types of car suspensions.

1. Independent suspension on two wishbones.

Two forked levers, usually triangular in shape, guide the rolling of the wheel. The rolling axis of the arms is parallel to the longitudinal axis of the vehicle. Over time, double wishbone independent suspension has become standard equipment in cars. At one time, she proved the following indisputable advantages:

Light unsprung weight

Little space requirement

Possibility of adjusting the car's handling

Available combination with front-wheel drive

The main advantage of such a suspension is the ability for the designer, by choosing a certain geometry of the levers, to rigidly set all the main settings for the suspension - changing the camber and track during compression and rebound strokes, the height of the longitudinal and transverse roll centers, and so on. In addition, such a suspension is often completely mounted on a cross member attached to the body or frame, and thus is a separate unit that can be completely removed from the vehicle for repair or replacement.

From the point of view of kinematics and controllability, double wishbones are considered the most optimal and perfect type, which leads to a very widespread use of such a suspension in sports and racing cars. In particular, all modern Formula 1 race cars have just such a suspension, both front and rear. Most sports cars and executive sedans these days also use this type of suspension on both axles.

Advantages: one of the most optimal suspension schemes and that says it all.

Disadvantages: layout restrictions associated with the length of the wishbones (the suspension itself "eats away" a fairly large space in the engine or luggage compartment).

2. Independent slanting link suspension.

The pivot axle is located diagonally to the longitudinal axis of the vehicle and tilted slightly towards the middle of the vehicle. This type of suspension cannot be fitted to front-wheel drive vehicles, although it has proven effective in rear-wheel drive small and medium-sized vehicles.

TO Trailing-arm or slant-arm mounting is practically not used in modern cars, but the presence of this type of suspension, for example, in the classic Porsche 911, is definitely a topic for discussion.

Advantages:

Disadvantages:

3. Oscillating axle independent suspension.

The independent swing-axle suspension is based on Rumpler's patent from 1903, which was used by Daimler-Benz until the seventies of the 20th century. The left axle tube is rigidly connected to the main gear housing, and the right tube has a spring connection.

4. Independent trailing arm suspension.

The independent trailing arm suspension was patented by Porsche. TO Trailing-arm or slant-arm mounting is practically not used in modern cars, but the presence of this type of suspension, for example, in the classic Porsche 911, is definitely a topic for discussion. In contrast to other solutions, the advantage of this type of suspension was that this type of axle was connected to a transverse torsion spring bar, which created more space. The problem, however, was that there were reactions of strong lateral vibrations of the car, which could lead to a loss of control, which, for example, "became famous" of the "Citroen" model "2 CV".

This type of independent suspension is simple but imperfect. When such a suspension works, the wheelbase of the car changes within a fairly wide range, although the track remains constant. When turning, the wheels tilt in it together with the body significantly more than in other suspension designs. The oblique levers make it possible to partially get rid of the main drawbacks of the suspension on the trailing arms, but with a decrease in the effect of body roll on the inclination of the wheels, a change in track appears, which also affects handling and stability.

Advantages: simplicity, low cost, relative compactness.

Disadvantages: outdated design, extremely far from perfect.

5. Independent suspension with wishbone and spring strut (McPherson).

The so-called "McPherson suspension" was patented in 1945. It was a further development of the double wishbone suspension, in which the upper control arm was replaced by a vertical guide. The McPherson struts are designed for use with both front and rear axles. In this case, the wheel hub is connected to the telescopic tube. The entire rack is connected to the front (steerable) wheels by means of hinges.

MacPherson first used the 1948 Ford Vedet in a production car from the French subsidiary of the company. It was later used on the Ford Zephyr and Ford Consul, which also claim to be the first high-volume vehicles with such a suspension, as the Vedette plant in Poissy initially had great difficulty getting the new model into production.

Much similar suspension was developed earlier, right up to the very beginning of the XX century, in particular, a very similar type was developed by the engineer of the company "Fiat" Guido Fornaca in the mid-twenties - it is believed that MacPherson partially took advantage of his developments.

The immediate ancestor of this type of suspension is a type of front suspension with two wishbones of unequal length, in which the spring in a single block with a shock absorber was placed in the space above the upper arm. This made the suspension more compact, and made it possible to skip a semi-axle with a hinge between the levers on a front-wheel drive car.

Replacing the upper arm with a ball joint and a shock absorber and spring block located above it with a shock absorber strut with a swivel joint attached to the mudguard, MacPherson received a compact, structurally simple and cheap suspension named after him, which was soon used on many Ford models European market.

In the original version of such a suspension, the ball joint was located on the continuation of the axis of the shock absorber, so the axis of the shock absorber was also the axis of rotation of the wheel. Later, for example, on the Audi 80 and Volkswagen Passat of the first generations, the ball joint began to be displaced outward towards the wheel, which made it possible to obtain smaller and even negative values ​​of the run-in shoulder.

This suspension received mass distribution only in the seventies, when technological problems were finally solved, in particular, the mass production of shock absorber struts with the required resource. Due to its manufacturability and low cost, this type of suspension subsequently quickly found very widespread use in the automotive industry, despite a number of disadvantages.

In the eighties, there was a trend towards widespread use of MacPherson strut suspension, including on large and relatively expensive cars. However, subsequently, the need for a further increase in technical and consumer qualities led to a return on many relatively expensive cars to a double wishbone suspension, which is more expensive to manufacture, but has better kinematic parameters and increases driving comfort.

Chapman Rear Suspension - MacPherson strut version for the rear axle.

McPherson designed his suspension to be installed on all wheels of the car, both front and rear - in particular, this is how it was used in the Chevrolet Cadet project. However, on the first production models, the suspension of his development was applied only in front, and the rear, for reasons of simplification and reduction in cost, remained traditional, dependent with a rigid drive axle on longitudinal springs.

Only in 1957, Lotus engineer Colin Chapman used a similar suspension for the rear wheels of the Lotus Elite model, so it is commonly called "Chapman's suspension" in English-speaking countries. But, for example, in Germany such a difference is not made, and the combination "MacPherson strut rear suspension" is considered quite acceptable.

The most significant advantages of the system are its compactness and low unsprung weight. Suspension "McPherson" has become widespread due to its low cost, ease of manufacture, compactness, as well as the possibility of further refinement.

6. Independent suspension with two transverse springs.

In 1963, General Motors developed the Corvette with an exceptional suspension solution - an independent suspension with two transverse springs. In the past, coil springs were preferred over springs. Later, in 1985, the first editions of the Corvette were again equipped with a suspension with transverse springs made of plastic. However, in general, these designs have not been successful.

7. Independent candle suspension.

This type of suspension was installed on early Madeleys, such as the Lancia Lambda (1928). In this type of suspension, the wheel, together with the steering knuckle, moves along a vertical guide mounted inside the wheel casing. A coil spring is installed inside or outside this guide. This design, however, does not provide the wheel alignment required for optimal road contact and handling.

WITH The most common type of independent suspension in a passenger car today. It is characterized by simplicity, low cost, compactness and relatively good kinematics.

This suspension is on a rail and a single wishbone, sometimes with an additional trailing link. The main idea in the design of this suspension scheme was by no means handling and comfort, but compactness and simplicity. With fairly average indicators, multiplied by the need to seriously strengthen the place of attachment of the pillar to the body and a rather serious problem of road noise transmitted to the body (and a whole bunch of shortcomings), the suspension turned out to be so technologically advanced and so liked the linkers that it is still used almost everywhere ... In fact, only this suspension allows designers to position the power unit transversely. MacPherson strut suspension can be used for both the front and rear wheels. However, in English-speaking countries, a similar rear-wheel suspension is commonly referred to as "Chapman's suspension". Also, this suspension is sometimes called the term "candle suspension" or "swinging candle". Today, there is a tendency to move from the classic MacPherson strut to a scheme with an additional upper wishbone (a kind of hybrid of MacPherson strut and wishbone suspension is obtained), which allows, while maintaining a relative compactness, to significantly improve handling performance.

Advantages: simplicity, low cost, small unsprung masses, a successful scheme for various layout solutions in small spaces.

Disadvantages: noise, low reliability, low roll compensation ("peck" when braking and "squat" when accelerating).

8. Dependent suspension.

The dependent suspension is mainly used for the rear axle. It is used as a front suspension on jeeps. This type of suspension was the main one until about the thirties of the 20th century. They also included coil springs. The problems associated with this type of suspension relate to the large mass of unsprung parts, especially for the axles of the driven wheels, as well as the inability to provide optimal wheel alignment angles.

WITH The oldest type of suspension. Its history dates back to carts and carts. Its main principle is that the wheels of one axle are interconnected by a rigid beam, most often called a "bridge".

In most cases, if you do not touch upon exotic schemes, the bridge can be fixed both on springs (reliable, but not comfortable, rather mediocre handling) and on springs and guide levers (only slightly less reliable, but the comfort and controllability becomes much more) ... It is used where something really strong is required. After all, nothing has been invented yet stronger than a steel pipe, in which, for example, drive axle shafts are hidden. It practically does not occur in modern passenger cars, although there are exceptions. Ford Mustang, for example. It is used more often in SUVs and pickups (Jeep Wrangler, Land Rover Defender, Mercedes Benz G-Class, Ford Ranger, Mazda BT-50, and so on), but the trend towards a general transition to independent circuits is visible with the naked eye - handling and speed are now more in demand than the "armor-piercing" of the structure.

Advantages: reliability, reliability, reliability and again reliability, simplicity of design, constant track and ground clearance (off-road this is a plus, and not a minus, as for some reason many believe), large moves that allow you to overcome serious obstacles.

Disadvantages: When working out irregularities and in turns, the wheels always move together (they are rigidly connected), which, together with high unsprung masses (a heavy axle is an axiom), does not have the best effect on the stability of movement and controllability.

On a transverse spring

This very simple and cheap type of suspension was widely used in the first decades of the development of the car, but as speeds increased, it almost completely fell out of use.
The suspension consisted of a continuous beam of the bridge (leading or not leading) and a semi-elliptical transverse spring located above it. In the suspension of the drive axle, it became necessary to place its massive gearbox, so the transverse spring had the shape of a capital letter "L". To reduce spring compliance, longitudinal jet thrust was used.
This type of suspension is best known for Ford T and Ford A / GAZ-A vehicles. This type of suspension was used on Ford vehicles up to and including the 1948 model. GAZ engineers abandoned it already on the GAZ-M-1 model, created on the basis of the Ford B, but with a completely redesigned suspension on longitudinal springs. The rejection of this type of suspension on a transverse spring in this case was due to the greatest extent to the fact that, according to the operating experience of the GAZ-A, it had insufficient survivability on domestic roads.

On longitudinal springs

This is the most ancient version of the suspension. In it, the bridge beam is suspended on two longitudinally oriented springs. The bridge can be either leading or not leading, and is located both above the spring (usually on cars) and under it (trucks, buses, SUVs). As a rule, the axle is attached to the spring using metal clamps approximately in the middle of it (but usually with a slight forward displacement).

The spring in its classic form is a package of elastic metal sheets, connected with clamps. The sheet on which the spring attachment ears are located is called the root - as a rule, it is made the thickest.
In recent decades, there has been a transition to small or even single-sheet springs, sometimes non-metallic composite materials (carbon fiber reinforced plastics and so on) are used for them.

With guide levers

There are a variety of schemes for such suspensions with different numbers and arrangement of levers. The five-link dependent suspension with Panhard rod shown in the figure is often used. Its advantage is that the levers rigidly and predictably set the drive axle movement in all directions - vertical, longitudinal and lateral.

More primitive options have less leverage. If there are only two levers, during the operation of the suspension they tilt, which either requires their own flexibility (for example, on some Fiats of the early sixties and English sports cars, the levers in the spring rear suspension were made elastic, plate, in fact - similar to quarter-elliptical springs) , or a special articulated connection of the levers with the beam, or the flexibility of the beam itself to torsion (the so-called torsion bar suspension with coupled levers, which is still widespread on front-wheel drive cars
As elastic elements, both coil springs and, for example, pneumatic bellows can be used. (especially on trucks and buses, as well as - flowriders)... In the latter case, a rigid setting of the movement of the suspension guide vane in all directions is required, since the air bellows are not able to perceive even small lateral and longitudinal loads.

9. De-Dion type dependent suspension.

Firm "De Dion-Bouton" in 1896 developed a rear axle design, which made it possible to separate the differential housing and the axle. In the suspension of the "De Dion-Bouton" design, the torque was perceived by the bottom of the car body, and the drive wheels were attached to the rigid axle. With this design, the mass of non-shock-absorbing parts was significantly reduced. This type of suspension was widely used by Alfa Romeo. It goes without saying that such a suspension can only work on the rear driving axle.

Suspension "De Dion" in a schematic image: blue - continuous suspension beam, yellow - final drive with differential, red - axle shafts, green - hinges on them, orange - frame or body.

Suspension "De Dion" can be described as an intermediate type between dependent and independent suspensions. This type of suspension can only be used on drive axles, more precisely, only the drive axle can have the "De Dion" type of suspension, since it was developed as an alternative to the continuous drive axle and implies the presence of driving wheels on the axle.
In the "De Dion" suspension, the wheels are connected by a relatively light, one way or another sprung continuous beam, and the main gear reducer is fixedly attached to the frame or body and transmits rotation to the wheels through axle shafts with two hinges on each.
This allows unsprung masses to be kept to a minimum (even when compared to many independent suspension types). Sometimes, to improve this effect, even the brakes are transferred to the differential, leaving only the wheel hubs and the wheels themselves unsprung.
During the operation of such a suspension, the length of the axle shafts changes, which forces them to be carried out with hinges of equal angular velocities movable in the longitudinal direction (as on front-wheel drive cars). The English Rover 3500 used conventional universal joints, and to compensate, the suspension beam had to be made with a unique sliding joint design that allowed it to increase or decrease its width by several centimeters when the suspension was compressed and rebounded.
"De Dion" is a technically very perfect type of suspension, and in terms of kinematic parameters it surpasses even many types of independent ones, yielding to the best ones only on uneven roads, and then in some indicators. At the same time, its cost is quite high (higher than that of many types of independent suspension), therefore it is used relatively rarely, usually on sports cars. For example, many Alfa Romeo models had such a suspension. A recent car with such a suspension is Smart.

10. Dependent suspension with drawbar.

This suspension can be considered as semi-independent. In its current form, it was developed in the seventies for compact cars. For the first time this type of axle was serially installed on the Audi 50. Today, the Lancia Y10 is an example of such a car. The suspension is assembled on a tube bent in front, at both ends of which wheels with bearings are mounted. The forward bend forms the actual drawbar, which is fixed to the body with a rubber-metal bearing. Lateral forces are transmitted by two symmetrical oblique jet rods.

11. Dependent suspension with tied arms.

The linked-arm suspension is an axle that is a semi-independent suspension. The suspension has rigid trailing arms connected to each other by a rigid elastic torsion bar. This design, in principle, makes the levers vibrate in sync with each other, but by twisting the torsion bar it gives them some degree of independence. This type can be conventionally considered semi-dependent. In this form, the suspension is used on the Volkswagen - Golf model. In general, it has quite a lot of design variations and is very widely used for the rear axle of front-wheel drive vehicles.

12. Torsion bar suspension

Torsion bar suspension- these are metal torsion shafts operating in torsion, one end of which is attached to the chassis, and the other is attached to a special perpendicularly standing lever connected to the axle. The torsion bar suspension is made of heat treated steel, which allows it to withstand significant torsional loads. The basic principle of the torsion bar suspension is bending.

The torsion beam can be positioned longitudinally and transversely. Longitudinal torsion bar suspension is mainly used on large and heavy trucks. On passenger cars, as a rule, a transverse arrangement of torsion suspensions is used, usually on a rear wheel drive. In both cases, the torsion bar suspension provides a smooth ride, regulates roll when cornering, provides an optimal amount of damping of oscillations of the wheels and body, and reduces oscillations of the steered wheels.

On some vehicles, the torsion bar suspension is used for automatic leveling using a motor that pulls the beams together to provide additional rigidity, depending on the speed and condition of the road surface. The height-adjustable suspension can be used when changing wheels where the vehicle is raised with three wheels and the fourth is raised without a jack.

The main advantages of torsion suspensions are durability, ease of height adjustment and compactness across the width of the vehicle. It takes up significantly less space than coil springs. The torsion bar suspension is very easy to operate and maintain. If the torsion bar suspension is loose, you can adjust the positions using a conventional wrench. It is enough to climb under the bottom of the car and tighten the necessary bolts. However, the main thing is not to overdo it in order to avoid excessive motion stiffness. Adjusting torsion bar suspensions is much easier than adjusting spring suspensions. Car manufacturers are changing the torsion beam to adjust travel position based on engine weight.

The prototype of the modern torsion bar suspension is the device that was used in the Volkswagen Beatle in the 1930s. This device was modernized by the Czechoslovak professor Ledwinka to the design we know today and was installed on the Tatra Mountains in the mid-1930s. And in 1938 Ferdinand Porsche copied the design of Ledwinky's torsion bar suspension and introduced it into the mass production of the KDF-Wagen.

The torsion bar suspension was widely used on military equipment during the Second World War. After the war, automotive torsion bar suspension was used mainly on European cars (including passenger cars) such as Citroen, Renault and Volkswagen. Over time, passenger car manufacturers abandoned the use of torsion suspensions on passenger cars due to the complexity of manufacturing torsion bars. These days, torsion bar suspension is mainly used on trucks and SUVs from manufacturers such as Ford, Dodge, General Motors and Mitsubishi Pajero.

Now about the most common misconceptions.

"The spring sagged and became softer":

No, the spring rate does not change. Only its height changes. The turns get closer to each other and the machine sinks lower.
1. "The springs are straightened, so they sagged": No, if the springs are straight, this does not mean that they are sagging. For example, on the factory assembly drawing of the UAZ 3160 chassis, the springs are absolutely straight. At Hunter, they have a bend of 8mm, which is barely noticeable to the naked eye, which, of course, is also perceived as "straight springs". In order to determine whether the springs have sagged or not, you can measure some characteristic size. For example, between the bottom surface of the frame above the bridge and the surface of the bridge stocking under the frame. Should be about 140mm. And further. These springs are not conceived by direct chance. When the axle is located under the spring, only in this way can they provide a favorable meltability characteristic: when heeling, do not steer the axle towards oversteer. You can read about understeer in the "Vehicle handling" section. If in some way (by adding sheets, forging resors, adding springs, etc.) to achieve that they become curved, then the car will be prone to yaw at high speed and other unpleasant properties.
2. "I will cut off a couple of turns from the spring, it will sag and become softer.": Yes, the spring will indeed become shorter and it is possible that when installed on a car, the car will sag lower than with a full spring. However, in this case, the spring will not become softer but, on the contrary, harder in proportion to the length of the sawn bar.
3. “I will add springs (combined suspension) to the springs, the springs will relax and the suspension will become softer. During normal driving, the springs will not work, only the springs will work, and the springs only at maximum breakdowns " : No, the stiffness in this case will increase and will be equal to the sum of the stiffness of the spring and the spring, which will negatively affect not only the comfort level, but also the cross-country ability (about the effect of suspension stiffness on comfort later). In order to achieve a variable suspension characteristic by this method, it is necessary to bend the spring to the free state of the spring and bend through this state (then the spring will change the direction of force and the spring and spring will start to work at the spring). And for example, for a UAZ small leaf spring with a stiffness of 4kg / mm and a sprung mass of 400kg per wheel, this means a suspension lift of more than 10cm !!! Even if this terrible lift is carried out with a spring, then in addition to the loss of stability of the car, the kinematics of the curved spring will make the car completely uncontrollable (see paragraph 2)
4. "And I (for example, in addition to item 4) will reduce the number of sheets in the spring": The reduction in the number of sheets in the spring really clearly means a decrease in the stiffness of the spring. However, firstly, this does not necessarily mean a change in its bending in a free state, secondly, it becomes more prone to an S-shaped bend (winding water around the bridge by the action of the reactive moment on the bridge) and thirdly, the spring is designed as a "beam of equal resistance bending "(who studied" SoproMat ", he knows what it is). For example, 5-leaf springs from the Volga-sedan and more rigid 6-leaf springs from the Volga station wagon have the same root leaf only. It would seem that in production it is cheaper to unify all parts and make only one additional sheet. But this is not possible because if the condition of equal resistance to bending is violated, the load on the spring sheets becomes uneven in length and the sheet quickly fails in a more loaded area. (The service life is shortened). I really do not recommend changing the number of sheets in a package, and even more so collecting springs from sheets from different brands of cars.
5. "I need to increase the rigidity so that the suspension does not break through to the bumpers" or "the SUV must have a rigid suspension." Well, first of all, they are called "chippers" only in the common people. In fact, these are additional elastic elements, i.e. they stand there specially in order to break through to them and so that at the end of the compression stroke the stiffness of the suspension increases and the necessary energy consumption is provided with a lower stiffness of the main elastic element (springs / springs). With an increase in the rigidity of the main elastic elements, the permeability also deteriorates. It would seem what is the connection? The traction limit for adhesion that can be developed on a wheel (in addition to the coefficient of friction) depends on the force with which this wheel is pressed against the surface on which it is traveling. If the car is driving on a flat surface, then this pressing force depends only on the mass of the car. However, if the surface is not level, this force begins to depend on the stiffness characteristic of the suspension. For example, imagine 2 cars of equal sprung mass, 400 kg per wheel, but with different stiffness of the suspension springs 4 and 2 kg / mm, respectively, moving on the same uneven surface. Accordingly, when driving through an unevenness with a height of 20 cm, one wheel worked for compression by 10 cm, the other for rebound by the same 10 cm. When the spring with a stiffness of 4kg / mm is expanded by 100mm, the spring force decreased by 4 * 100 = 400kg. And we have only 400kg. This means that there is no more traction on this wheel, but if we have an open differential or a limited-friction differential (DOT) on the axle (for example, a screw "Quife"). If the stiffness is 2 kg / mm, then the spring force has decreased only by 2 * 100 = 200 kg, which means that 400-200-200 kg is still pressing and we can provide at least half the thrust on the axle. Moreover, if there is a bunker, and most of them have a blocking coefficient of 3, if there is some kind of traction on one wheel with the worst traction, 3 times more torque is transferred to the second wheel. And an example: The softest UAZ suspension on low-leaf springs (Hunter, Patriot) has a stiffness of 4kg / mm (both spring and spring), while the old Range Rover has about the same mass as the Patriot, on the front axle 2.3 kg / mm, and on the back 2.7kg / mm.
6. "In cars with soft independent suspension, the springs should be softer." : Not necessary at all. For example, in a MacPherson-type suspension, the springs really work directly, but in suspensions with double wishbones (front VAZ-classic, Niva, Volga) through a gear ratio equal to the ratio of the distance from the lever axis to the spring and from the lever axis to the ball joint. With this arrangement, the stiffness of the suspension is not equal to the stiffness of the spring. The spring rate is much higher.
7. "It is better to use stiffer springs so that the car is less rolling and therefore more stable." : Not certainly in that way. Yes, indeed, the greater the vertical stiffness, the greater the angular stiffness (which is responsible for body roll under the action of centrifugal forces in corners). But the transfer of masses due to body roll has a much smaller effect on the stability of the car than, say, the height of the center of gravity, which Jeepers often throw very wastefully to lift the body just in order not to cut the arches. The car must roll, roll is not bad. This is important for driving information. Most cars are designed with a standard roll value of 5 degrees at a peripheral acceleration of 0.4g (depending on the ratio of the turning radius to the speed of movement). Some automakers use a smaller roll angle to create the illusion of stability for the driver.

Frame, wheels, bridge beams. Suspension device, suspension diagram and suspension structure in articles and figures. Tips from experienced craftsmen in suspension repair.

NSone part of the car serves to move vehicles along the road.The chassis is arrangedin such a way that it is convenient for a person to move around comfortably.

DIn order for the car to move, the chassis parts connect the body to the wheels, dampen vibrations while driving, soften, absorb shocks and forces. And for In order to avoid shaking and excessive vibration during driving, the chassis includes the following elements and mechanisms: elastic suspension elements, wheels and tires.

NSOne part of the car consists of the following main elements:

1. R and we

2. B alok bridges

3. NS front and rear wheel suspension

4. TO oles (wheels, tires)

T Types of car suspensions:

MacPherson pendant

MacPherson suspension device -MacPherson strut this is the so-called suspension on the guide racks. This type of suspension involves the use of a shock absorber as the main element. The McPherson suspension can be used for both the rear and front wheels.

Independent suspension

independent suspension called , because the wheels of one axle are not rigidly connected, this ensures the independence of one wheel from the other (the wheels do not exert any influence on each other).

Modern suspension design. Modern pendant it is an element of a car that performs damping and damping properties, which is associated with the vibrations of the car in the vertical direction. The quality and characteristics of the suspension will allow passengers to experience maximum travel comfort. Among the main parameters of the car's comfort, one can recognize the smoothness of the body vibration.

- balance suspension especially suitable for the rear wheels of a car, which have a front drive axle, this is argued by the fact that such a suspension takes up almost no space on the frame. Balance suspension It is used mainly on three-axle vehicles, the middle and rear drive axles in which are located next to each other. It is sometimes used on four-axle vehicles and multi-axle trailers. Balance suspension is of two types: dependent and independent... Dependent pendants have become very popular.

Truck suspension device - this is a section in which you can study the structure, purpose, principle of operation of a truck suspension. ZIL car suspension - a section in which the suspension device of a ZIL 130 truck is described in detail.

The suspension provides an elastic connection between the frame or body with the axles of the vehicle or directly with its wheels, absorbing vertical forces and setting the required smoothness. Also, the suspension serves to absorb the longitudinal and transverse forces and reactive moments that act between the support plane and the frame. The suspension ensures the transmission of pushing and twisting forces.

- Vehicle rear suspension device

- Balance suspension device

- Dependent pendants

- Rear suspension of a three-axle vehicle

NScar chassis elements:

- steering axle is a beam in which pivots and connecting elements are mounted on the hinges. The rigid stamped beam forms the basis of the steering axle. Respectivelyfront steering axleit is a conventional cross member with driven steer wheels, which are not supplied with torque from the engine. This axle is not a driving one and serves to support the car's supporting system and ensure its rotation. There is a large list of different types of steering axles that are used on trucks (6x2) and cars (4x2).

- Elastic elements of the machine suspension- atother elements of the car suspension designed to cushion shocks and shocks, as well as to reduce vertical acceleration and dynamic load, which is transmitted to the structure when the vehicle is moving. Elastic suspension elements allow avoiding the direct impact of road irregularities on the body profile and provide the necessary smoothness. The limits of optimum smoothness range from 1-1.3 Hz.

The car suspension is a set of elements that provide an elastic connection between the body (frame) and the wheels (axles) of the car. Mainly, the suspension is designed to reduce the intensity of vibration and dynamic loads (shocks, shocks) acting on a person, the transported cargo or structural elements of the vehicle when driving on an uneven road. At the same time, it must ensure constant contact of the wheel with the road surface and effectively transmit the driving force and braking force without deviating the wheels from the corresponding position. Correct suspension function makes driving comfortable and safe. Despite the seeming simplicity, the suspension is one of the most important systems of a modern car and has undergone significant changes and improvements over the history of its existence.

History of appearance

Attempts to make the movement of a vehicle softer and more comfortable were made even in carriages. Initially, the axles of the wheels were rigidly attached to the body, and every unevenness in the road was transmitted to the passengers sitting inside. Only soft seat cushions could improve the level of comfort.

Dependent suspension with transverse leaf springs

The first way to create an elastic "layer" between the wheels and the carriage body was the use of elliptical springs. Later, this solution was borrowed for the car. However, the spring had already become semi-elliptical and could be installed transversely. A car with such a suspension handled poorly even at low speeds. Therefore, soon the springs began to be installed longitudinally on each wheel.

The development of the automotive industry has led to the evolution of the suspension. Currently, there are dozens of their varieties.

The main functions and characteristics of the car suspension

Each suspension has its own characteristics and working qualities that directly affect the handling, comfort and safety of passengers. However, any suspension, regardless of its type, must perform the following functions:

1. Absorbing shocks and shocks from the road to reduce the load on the body and increase driving comfort.
2. Vehicle stabilization while driving by ensuring constant contact of the tire of the wheel with the road surface and limiting excessive body roll.
3. Preservation of the specified travel geometry and position of the wheels to maintain precise steering while driving and braking.

The vehicle's rigid suspension is suitable for dynamic driving that requires an instant and precise response to the driver's actions. It provides low ground clearance, maximum stability, roll and body roll resistance. It is mainly used in sports cars.

Most passenger cars use a soft suspension. It smoothes out irregularities as much as possible, but makes the car a little rolly and worse controllable. If an adjustable stiffness is required, a helical suspension is mounted on the vehicle. It is a shock absorber rack with variable spring tension.

Suspension travel - the distance from the extreme upper position of the wheel when compressed to the extreme lower position when hanging the wheels. The suspension travel largely determines the off-road capabilities of the vehicle. The larger its value, the larger the obstacle can be overcome without hitting the limiter or without sagging the driving wheels.

Suspension device

Any car suspension consists of the following basic elements:

1. Elastic device- perceives loads from unevenness of the road surface. Types: springs, springs, pneumatic elements, etc.
2. Damping device- dampens body vibrations when driving over bumps. Types: all types.
3. Guiding device—provides a predetermined movement of the wheel relative to the body. Views: levers, transverse and jet rods, springs. Pull-rod and push-rod sport suspensions use rockers to change the direction of action on the damping element.
4. Anti-roll bar- reduces lateral body roll.
5. Rubber-metal hinges- provide an elastic connection of the suspension elements to the body. Partially absorb, cushion shocks and vibrations. Types: silent blocks and bushings.
6. Suspension travel stops- limit the travel of the suspension in extreme positions.

Suspension classification

Basically, suspensions are divided into two large types: and independent. This classification is determined by the kinematic diagram of the suspension guide.

Dependent suspension

The wheels are rigidly connected by means of a beam or continuous bridge. The vertical position of a pair of wheels relative to the common axis does not change, the front wheels are swivel. The rear suspension device is similar. There are spring, spring or pneumatic ones. In the case of installing springs or pneumatic bellows, it is necessary to use special rods to fix the bridges from moving.

• simple and reliable in operation;
• high carrying capacity.

• poor handling;
• poor stability at high speeds;
• less comfort.

Independent suspension

The wheels can change their vertical position relative to each other, while remaining in the same plane.

• good handling;
• good vehicle stability;
• great comfort.

• more expensive and complex construction;
• less reliability during operation.

Semi-independent suspension or torsion beam Is an intermediate solution between dependent and independent suspension. The wheels are still connected, but there is a possibility of them moving slightly relative to each other. This property is provided due to the elastic properties of the U-shaped beam connecting the wheels. This suspension is mainly used as the rear suspension for budget cars.

Types of independent suspensions

McPherson

- the most common front axle suspension in modern cars. The lower arm is connected to the hub by means of a ball joint. Depending on its configuration, longitudinal jet thrust can be used. An amortization strut with a spring is attached to the hub unit, its upper support is fixed to the body.

The transverse link, fixed to the body and connecting both arms, is a stabilizer that counteracts the roll of the car. The lower ball joint and shock absorber cup bearing allow for wheel rotation.

The rear suspension parts are made according to the same principle, the only difference is that there is no possibility of turning the wheels. The lower arm is replaced with longitudinal and transverse rods that fix the hub.

• simplicity of design;
• compactness;
• reliability;
• inexpensive to manufacture and repair.

• average handling.

Double wishbone front suspension

More efficient and sophisticated design. The second wishbone is the upper attachment point for the hub. A spring or can be used as an elastic element. The rear suspension has a similar structure. This suspension arrangement provides better vehicle handling.

Air suspension

The role of springs in this suspension is performed by compressed air bellows. With there is the possibility of adjusting the height of the body. It also improves ride quality. Used on luxury cars.

Hydraulic suspension

The shock absorbers are connected to a single closed circuit with hydraulic fluid. makes it possible to adjust the rigidity and ride height. If the vehicle has control electronics and functions, it automatically adjusts to the road and driving conditions.

Sports independent suspension

Helical suspension, or coilovers - shock absorbers with the ability to adjust the stiffness directly on the car. Thanks to the threaded connection of the lower spring stop, its height can be adjusted, as well as the amount of ground clearance.

Suspension type push-rod and pull-rod

These devices were designed for open-wheel racing cars. It is based on a double wishbone scheme. The main feature is that the damping elements are located inside the body. The design of these types of suspension is very similar, the only difference is in the location of the load-bearing elements.

Sports suspension push-rod: load-bearing element - pusher, works in compression.

If you ask any motorist what is the most important part of the car, then the majority will answer that it is the engine, as it drives the car. Others will say that the most important thing is the body. Still others will say that one cannot go far without a checkpoint. But very few people remember about the suspension and how it matters. But this is the foundation on which the car is built. It is the suspension that determines the overall dimensions and features of the body. The system also determines the ability to install a particular engine. So let's see what a car suspension is.

Appointment

This is a complex of very closely working elements and devices, the functional feature of which is determined by the provision of an elastic connection between the sprung mass and the unsprung mass. The suspension system also reduces the load placed on the sprung mass by distributing dynamics more evenly throughout the vehicle. Among the most important components in the suspension of any car, there are several elements.

Thus, the elastic elements are designed to provide a smooth ride. Due to them, the effect of vertical dynamics on the body is reduced. Damping elements and devices are designed to convert vibrations into thermal energy. Due to this, the driving dynamics are normalized. The guide parts process the lateral and longitudinal kinetic energy on the moving wheels of the car.

Regardless of the type of chassis, the general purpose of a car's suspension is to absorb incoming vibration and noise, and to smooth out vibrations that will necessarily occur when driving on flat and uneven surfaces. Depending on the specifics of the car, the design features and the type of suspension will differ.

How does the system work?

Regardless of the type of system, this complex includes a set of elements, without which it is difficult to imagine an efficient chassis. The main group includes elastic buffers, spreading parts, shock absorbers, a rod, and also fasteners.

The elastic buffer is needed to analyze and transmit information to the body during the processing of road irregularities. It can be springs, springs, torsion bars - any details that smooth out vibrations.

The distributor parts are fixed at the same time in the suspension system and attached to the car body. This allows for the transfer of power. These elements are levers.

Shock absorbers use the hydraulic resistance method. The shock absorber resists elastic elements. There are two types - one-pipe and two-pipe models. Also, devices are classified into oil, gas-oil, and pneumatic.

The bar is designed to stabilize lateral stability. This part is part of a complex complex that consists of supports, as well as lever mechanisms attached to the body. The stabilizer distributes the load when cornering and similar maneuvers.

Fasteners are often bolted connections and various bushings. One of the most popular elements in different types of suspensions are silent blocks and ball bearings.

Types of suspension systems

The first pendants appeared at the beginning of the 20th century. The first structures performed only the function of connection, and all the kinetics was transmitted directly to the body. But then, after numerous experiments and tests, developments were embodied that made it possible to significantly improve not only the design. These experiments have significantly raised the potential for future exploitation. Now you can find only a few representatives of those developments or even segments. Each type of suspension is worthy of a separate review or even an entire article.

Macpherson

This development, which was created by the designer E. McPherson, was first used about 50 years ago. Structurally, it has a single lever, stabilizer and swinging candles. Those who know well what a suspension is will say that this type is imperfect, and they will be right. But with all the shortcomings, this system is very affordable and popular with most manufacturers of budget cars.

Double wishbone systems

In this case, the guiding part is represented by two levers. This can be realized in the form of diagonal, transverse and longitudinal link systems.

Multi-link systems

Unlike double wishbones, here the structure is more serious. Therefore, there are advantages that provide the car with a smooth and smooth ride, improved maneuverability. But only premium cars are equipped with such solutions.

Torsion Link Systems

This design is similar to the types discussed above. But instead of the springs traditional for lever-type suspensions, torsion bars are used here. Despite its apparent simplicity, this solution significantly expands the operational efficiency. The components themselves are easy to maintain and customizable.

"De Dion"

This suspension was developed by engineer De Dion from France. Its peculiarity is that it reduces the load on the rear axle. The final drive housing is not fixed to the beam, but to the body part. This solution is found on all-wheel drive off-road cars. On passenger cars, this approach is unacceptable. This can cause various problems during acceleration and deceleration.

Rear dependent suspension systems

We have already covered, and now let's move on to the rear systems. This is a familiar to everyone type of suspension for passenger cars, which was very much loved by Soviet engineers. In the USSR, this type was very widely used, integrated and invented. The beam is attached to the body by means of elastic springs and trailing arms. But with excellent handling and stability in motion, the weight of the rear beam can overload the gearbox and crankcase. However, such a rear suspension on VAZ, Logan and other budget models is still popular.

Semi-dependent

Unlike the dependent scheme, which was discussed above, there is a cross member here. It is connected by two trailing arms.

With swinging axle shafts

In this type, the semi-axes are the basis of the design. Hinges are attached to one end of the part. The axles themselves are connected to the wheels. When the car is moving, the wheel will be perpendicular to the axle shaft.

On longitudinal and transverse levers

Here the main design is the trailing arm. It must relieve the supporting forces that act on the body. This system is very heavy, which does not make it popular in the market. And in the case of trailing arms, everything is better - this is a more flexible type in setting. Support arms reduce stress on the suspension mounts.

Slant-arm suspension

The solution is very similar to the trailing arm system. The difference is that the axles on which the levers swing are in this case set at a sharper angle. These systems are most often installed on the rear axle. The suspension can be found on German-made cars. Compared with the longitudinal type, here the roll in the corner is significantly reduced.

Suspension with double trailing and wishbones

Unlike a single-lever system, there are two levers per axle. They are placed across or longitudinally. Torsion bars and springs can be used to connect the levers. In addition, springs are often used. The suspension is compact, but not balanced for roughness.

Pneumatic and hydraulic suspension

These solutions use fully pneumatic or hydropneumatic springs. By themselves, these details are not the final version. They only make the movement more comfortable.

Both the car and the hydraulic are quite sophisticated, both provide high smoothness and excellent handling. Such systems can be connected to MacPherson strings or multi-link solutions.

Electromagnetic

This is an even more complex type, and the design is based on an electric motor. Two functions are performed at once - a shock absorber and an elastic element. At the head is a microcontroller and a sensor. This solution is highly secure, and the mechanism is switched by means of electric magnets. Naturally, the cost of the kit is very high, so it is not found on serial car models.

Adaptive suspensions

We know what a suspension is and what it is for. And this system is able to adapt itself to the driving conditions and the driver. Electronics is able to determine the degree of vibration reduction itself. It adjusts to the required operating modes. Adaptation is carried out by electromagnets or by liquid method.

Suspension system malfunctions

Car manufacturers are working hard on the reliability of the suspension. Many cars are even equipped with reinforced systems. But the quality of the roads reduces the efforts of engineers to zero. Drivers are faced with various vehicle suspension malfunctions. Several typical problems can be distinguished.

So, the angles of the front wheels are often violated. Levers are often deformed, spring stiffness decreases or they break. For one reason or another, the tightness of the shock absorbers is violated, the shock absorber supports are damaged, the stabilizer bushings wear out, the ball bearings and silent blocks wear out.

Even with regular maintenance, the suspension is still a consumable in Russia. Literally every year after winter, drivers have to be puzzled by replacing the car's suspension.

DIY diagnostics

The system should be diagnosed if there are problems with the car. This is the absence of rectilinear movement, various vibrations at speed, body swing when bypassing or driving through obstacles, uncharacteristic sounds, impacts on the body when hitting various obstacles.

Diagnostics of the car's front suspension can be performed either manually using a mount or on a computer stand. Using a mount, each element of the system is checked in turn for backlash. A visual inspection will also help to identify a malfunction - you can visually assess the condition of silent blocks and other elements. Ball joints are diagnosed by hand. If the support walks tightly in its holder, then it is in good order. If she walks easily, then she should be replaced. In the VAZ suspension, this can be done without replacing the lever. On most foreign cars, the ball goes as a whole together with the lever. Although there are craftsmen who are engaged in either drilling rivets on the lever and installing bolted supports. This allows for significant savings.

But to find out exactly what state the suspension is in, computer diagnostics of the car's suspension will help. This is a special stand where the entire system is checked using numerous sensors. The computer will very accurately assess the condition and show the worn out and items to be replaced.

Suspension service

Suspension durability depends on maintenance. How often the service should be carried out, there is no exact answer. The term depends on the nature of the ride and on the operation of the car. If the car is treated with care, then it will be enough to service the car suspension once a year. But it happens that strange sounds and subsidence of the car happen more often. In this case, it is necessary to diagnose and replace worn parts. Usually, maintenance comes down to replacing worn out silent blocks, ball joints and other elements.

If the rear dependent suspension of the car fails, then the rear wheels become a house. To solve the problem, it is enough to replace the repair kit. It does not take a lot of time. That’s all there is to say about suspension maintenance.

Suspension repairs can be challenging - the system has to work in tough conditions. And often drivers are faced with the fact that fasteners do not loosen due to corrosion. At the workshop, craftsmen use a pneumatic or electric tool, which greatly facilitates the process of unscrewing the fasteners. Repair and maintenance of the suspension at the workshop will require less time than if the same was done in a conventional garage.

So, we found out what the chassis of a car is, what types it is and what functions it performs in a car.

The road for traffic is rarely ideal. Even on a paved track, there are always cracks, potholes and bumps. Without the damping system, comfortable driving would be impossible, and the car body would not withstand the shock loads transmitted from the wheels for a long time. The car suspension is designed to absorb such a load, and, depending on the purpose and cost, has a different design.

Purpose and device of the car suspension

When the vehicle is moving, all vibrations arising from road irregularities are transmitted to the body. The task of the suspension is to soften or dampen such vibrations. An additional function is to ensure the connection of the body and the wheels, while the wheels have the ability to change their position independently of the body, by adjusting the direction of travel. Together with the wheels, the suspension is one of the essential elements of the chassis of the machine.

The suspension is a technically complex device consisting of the following parts:

1. Elastic elements - metallic and non-metallic parts that take on all the load from movement over irregularities, and, by virtue of their properties, distribute it to the body structure.
2. Damping devices (shock absorbers) - units with a pneumatic, hydraulic or combined structure, leveling body vibrations obtained from elastic parts.
3. Guide parts - various levers connecting the suspension to the body, and controlling the displacement of the wheels relative to each other and the body.
4. Anti-roll bars - elastic metal rods that connect the suspension and the body, and eliminate the possible roll of the machine when driving.
5. Wheel bearings - parts of the front axle in the form of steering knuckles that receive loads from the wheels and distribute them over the suspension.
6. Means for fastening parts, assemblies and assemblies, the task of which is to connect the suspension and the body to each other. These are rigid bolted joints, ball bearings or hinges, composite silent blocks.

Damping elements

The parts of the suspension that damp vibrations while the vehicle is in motion are called damping elements. These include the following devices:

1. Double-tube shock absorbers, consisting of inner and outer tubes, and performing the function of a reservoir and a piston, which are communicated by holes and multidirectional valves, which, due to the inertia of the working medium, inhibit reciprocating movements and damp vibrations.

Depending on the internal working environment, shock absorbers are divided into:

• Hydraulic;
• Gas-filled;
• Gas-hydraulic.

Elastic elements

The task of these suspension elements is to absorb shocks coming from the wheels of the car to the body, and represent the following parts:

1. Spring. The simplest element found in almost all types of suspension. For work efficiency, it can have a different shape.
2. Spring. The oldest suspension element is a set of steel sheets joined together and dampening vibrations due to mutual friction.
3. Pneumatic element. It acts as an alternative to the spring and is a rubber cushion into which air is pumped.
4. Torsion. An elastic compact element in the form of a rod, one end of which is connected to the suspension arm, and the other is clamped by a bracket on the body. When the suspension arm is moved, the rod acts as an elastic element and twists.
5. Stretcher. It is an intermediate part between the body and the suspension elements, forming one assembly unit with them.
6. Anti-roll bar. It is a rod connected through struts or wheel suspension arms to stabilize the movement of the vehicle.

Suspension principle

Car suspension works by converting the force of impact from a wheel hitting an uneven surface into the movement of elastic parts (springs). The severity of such movements is controlled and mitigated by damping devices (shock absorbers). As a result, the force of impacts transmitted to the body is reduced, which ensures a smoother ride.

The stiffness of the suspension varies greatly from car to car: the stiffer it is, the easier and more predictable the control, but less ride comfort. Soft creates ease of use, but at the expense of significantly reduced controllability (which is not recommended). For this reason, vehicle manufacturers always try to find a compromise between comfort and safety.

Suspension classification

In the modern automotive industry, the following types of suspensions are most often used:

1. MacPherson. Developed in 1960 by an engineer who gave the structure his name. Consists of the following parts:

• Anti-roll bar, or "swinging plug". It is attached to the body with a hinge and tends to swing when the wheel moves vertically.
• Block (spring element and telescopic shock absorber);
• Lever.

The advantage of the suspension is its low price, simplicity and reliability. The disadvantage is a noticeable change in the camber angle on the wheels.

2. Double-link. Consists of two levers of different lengths - upper short and lower long. This scheme is one of the most perfect, since the car on it has excellent lateral stability and low tire wear due to the minimum lateral displacement of the wheels.

3. Multi-link. It has a similar structure to the double-arm, but much more perfect and more complex. In it, all hinges, levers and silent blocks are attached to a special subframe. Numerous ball joints and rubberized bushings perfectly dampen shocks when hitting bumps and reduce noise in the cabin. This suspension arrangement provides the best tire grip, ride comfort and handling. The advantages of a multi-link suspension are as follows:

• Optimal wheel steering;
• Insulated longitudinal and lateral adjustments;
• Small unsprung masses;
• Wheel independence from each other;
• Excellent 4WD potential.

But the main drawback of the suspension is its high cost, although recently not only executive cars, but also golf-class cars have been equipped with such a unit.

4. Responsive. It carries fundamental differences from other types of mechanisms, being a logical and improved continuation of the hydropneumatic suspension, first implemented by Citroen and Mercedes. Its advantages are as follows:

• Low swing at high speed and minimal body roll;
• Forced damping;
• Automatic adaptation to any road surface;
• Excellent stability when driving straight ahead;
• Adaptation for the driver;
• High degree of security.

Different companies in the manufacture of the unit develop their own original scheme, but in general, the design consists of the following components:

• Adjustable anti-roll bars;
• Chassis control unit;
• Active shock absorber struts;
• Various sensors (ground clearance, irregularities, etc.).

The main disadvantage of the device is its complexity.

5. Type "De Dion". The invention of the French engineer has the main goal - to unload the rear axle of the vehicle as much as possible by separating the main gear housing, while it is attached directly to the body. The torque is transmitted through the axle shafts and CV joints, which allows the suspension to be both dependent and independent. The main design flaws are "squatting" on the rear wheels during a sharp start and "pecking" when braking.

6. Back dependent. The device can be observed on classic VAZ models, where cylindrical coil springs act as elastic elements. The rear axle beam "hangs" on them and is attached to the body with four trailing arms. The lateral jet thrust dampens roll and improves handling. The design does not provide good comfort and smooth running due to unsprung masses and a massive rear axle, but it is relevant when attaching the main gear housing, gearbox and other massive parts to the beam.

7. Semi-independent rear. It is widely used in many four-wheel drive vehicles, and consists of a pair of trailing arms, attached in the center to the cross member. This suspension has the following advantages:

• Compact size and relatively light weight;
• Ease of repair and maintenance;
• A noticeable decrease in unsprung masses;
• The best wheel kinematics.

The main disadvantage of the suspension is the impossibility of installing it on rear-wheel drive cars.

8. Pickups and SUVs. Depending on the purpose and weight of the car, there are three types of suspension:

• Independent front and dependent rear;
• Completely independent;
• Completely addicted.

In most cases, a leaf spring or spring suspension is installed on the rear axle, interacting with rigid one-piece axles. Springs are used in heavy jeeps and pickups due to their ability to withstand an impressive load, unpretentiousness and reliability. Such a suspension is inexpensive in cost, which influenced the equipping of some budget cars with it.

The spring circuit is long-stroke, soft, and not complicated in structure, therefore it is installed more often on light jeeps. Spring and torsion circuits are installed on the front axles.

9. Trucks. The trucks are equipped with dependent suspensions with longitudinal and transverse springs, and hydraulic shock absorbers. Such a scheme is as simple and cheap to manufacture as possible. But at high speeds, the driver is faced with poor handling, since the springs do not function well as guiding elements.