Multi-link suspension installed on both front-wheel drive and rear wheel drive vehicles. Its purpose is to create a sufficiently elastic connection between the body and the wheels of the car. This type of suspension is different increased stability cornering and smooth running, as it tends to dampen the largest part of the vibrations created during movement on uneven road surfaces.
This suspension was originally installed on rear axle car. Currently, there are many options for installing it on the front axle, regardless of the drive of the car, whether it is full, front or rear. It does not have a specific design and is a combination of a double wishbone suspension with longitudinal-transverse levers. Thus, low noise is achieved at large road bumps, smooth running, improved handling and a large range of adjustments.
Independent suspension device
The design features begin with the fact that wheel hubs are mounted on four levers, and therefore, there are additional adjustments to the position of the hub. The levers, in turn, are mounted on a stretcher.
The number of levers can vary from 3 to 5. In the most elementary layout, two lower ones are used: front and rear, and one upper. The front, as a rule, is responsible for the wheel toe, the rear takes on most of the mass of the car, transmitted through the spring, and the top transmits lateral forces and connects the wheel support and the subframe.
Also, stabilizers are actively used in the multi-link suspension. roll stability, which are used to reduce the roll of the car when passing sharp turns. Stabilizers are mounted on the hub supports with additional levers, and in the upper part with rubber supports. Most often, such a stabilizer is closely connected with the spring.
Video - Independent suspension on a VAZ in operation
Advantages of the multi-link system
1. Complete independence of the wheels from each other.
2. Compared to any other type of suspension, the mass of an independent suspension is much less. This is due to the use of aluminum in the manufacturing process.
3. Possibility of application in 4x4 layouts.
4. Independent multi-link suspension ensures increased grip with pavement.
5. High cornering stability and smooth running.
Flaws
1. Subtle sensitivity to the quality of the road surface. The use of such a suspension on low-quality pavement leads to wear of the components very quickly.
2. The levers of this suspension are a non-separable element, therefore, in the process of repair, it is often necessary to change the entire assembly, which costs a lot of money.
Like any other type of suspension, a multi-link system requires increased care. Timely replacement of worn parts will save you from the subsequent breakdown of still normal parts and accidents associated with a faulty suspension condition.
Diagnosis of malfunctions of an independent suspension can be carried out independently. To do this, you need to put the car on viewing hole jack up right wheel and using any mounting tool, shake the levers by inserting it into the gap between the two levers or any other parts (for example, between the lever and the subframe). The backlashes of the silent blocks found at the same time should be eliminated as soon as possible, since this greatly affects the angle of the wheels and contributes to uneven wear rubber.
Troubleshooting also includes checking the condition of shock absorbers, ball joints, rubber seals and bushings, levers and rods. Faulty parts found must be replaced immediately. At the same time, when buying new parts, pay attention to their quality. Saving on the quality of suspension parts can, in consequence, play a trick on you on the road. Be very careful about this matter.
When troubleshooting, use the technical literature for the repair of your particular car model, since the layout and methods of mounting the suspension on other car models vary greatly.
It is worth paying attention that if knocks are heard in the rear of the car, then the source of noise can be not only the suspension system, but also a poor mounting of the muffler, which can touch the levers or rods.
Do not forget that the good condition of the independent suspension will keep good handling car, will relieve premature tire wear and is an excellent prevention of traffic accidents.
Double wishbone suspension is a common type of independent suspension. The design of a double-lever suspension is based on the use of two levers, upper and lower, attached at one end to the body, and at the other end to the wheel hub.
At the dawn of the automobile era, cars differed from horse-drawn carriages only by the presence of an engine. Accordingly, the suspension in the form of a beam on elliptical springs migrated to them practically unchanged. However, its imperfection, as the speed of cars increased, made itself felt more and more, and as a result of the efforts of engineers and inventors, it was double-lever.
Cars of the early twentieth century, so unlike modern ones, were far from the concepts of "comfort" and "handling". Namely, this was not enough for buyers of by no means cheap cars.
It was possible to achieve acceptable driving performance with the start of the use of independent suspensions. They are like most automotive development, migrated to civil vehicles from motorsport. high speeds And dependent suspensions, turned out to be incompatible things. Handling on bends remained at the level of the same horse-drawn carriages. In addition, the body of the car was above the beams of the bridges, so the center of gravity was high. And if there were no problems when driving in a straight line, then fast turns had to be overcome almost at the speed of pedestrians.
Despite the fact that the double wishbone suspension appeared on cars before World War II, it is still considered the most balanced and optimal for a passenger car. In addition, on the cars of the most famous Formula 1 racing series, a “two-lever” is used. Russian motorists are familiar with this design firsthand - on, from Kopeyka to Seven, the front suspension was independent, double-lever.
Double wishbone design
Also, like almost a hundred years ago, it consists of two levers located transversely, one above the other. The lower one, through silent blocks, rests on a beam or subframe, and the upper one rests on the body. Other ends of the levers, .
To save space and achieve optimal kinematics of the suspension, levers of different lengths are used. The upper, short, is made in the form of the letter "A", and the lower one, in the form of the letter "L".
A spring, a torsion bar, an air spring or a semi-elliptical spring can be used as an elastic element in a double wishbone suspension. True, the latter is practically never found on passenger cars and is used only on light trucks.
Together with the shock absorber, the elastic element is attached at one end to the lower arm, and at the other to the car body.
Pros and cons of double wishbone suspension
As mentioned above, the independent double wishbone suspension gives the car good handling. But this is not its only merit. When driving over bumps, shocks during suspension operation are damped more efficiently, which in better side impact on ride comfort. And most importantly, this type of independent suspension is by far the most reliable.
If it is so good, then why is it not put on all cars? The problem is that the double wishbone suspension has significant disadvantage. The fact is that the upper lever quite noticeably "eats" engine compartment. And if you consider that the vast majority of modern cars are front-wheel drive, with a transverse engine, then the “two-lever” simply does not have a place in the back. Therefore, almost all A-, B- and C-class cars are content with a compact and cheaper to manufacture. For the same reason, double-wishbone suspension is practically not used on the rear axle of cars, because it reduces the useful volume of the trunk.
Sooner or later, any, even the most reliable suspension. Here another minus of the “two-lever” pops up. The fact is that now the levers are made non-separable. That is, both the ball joint and silent blocks are made in one piece. And the levers themselves, to reduce unsprung masses mainly made of aluminium. Therefore, when, say, “penny” silent blocks or a ball joint are worn out, you have to buy an expensive lever as a whole.
The condition of the suspension elements can be diagnosed independently. To do this, it is enough to jack up the desired wheel, and then, using the assembly tool, check the condition of the ball bearings and silent blocks. The latter are most often calculated for the entire life of the car and do not require attention. But the most vulnerabilities in a double wishbone suspension are a ball joint and a shock absorber. Despite the simplicity of the design, it is better to entrust the repair professional car mechanics, but, with the appropriate skills, devices and desire, you can do it yourself.
Multi-link suspension - complex, but effective method give the car the best possible adhesion with the road. But how does it work and why is it becoming more common?
Some parts of the car have been named in such a way that not every beginner will understand difficult terms. What's happened expansion tank, planetary gearboxes and banjo fittings, not everyone knows. In this list of "secret elements" there is not one link - a multi-link suspension. Everyone has heard about it and almost everyone knows about it. This is a suspension... made of several component links - levers.
While struts technically only need two suspension arms to normal operation assembled circuit, a multi-link suspension requires a minimum of three side arms and one vertical or trailing member. The purpose of each link is to limit and/or prevent the axle from moving in six degrees of freedom: up and down, left and right, forward and backward. Sometimes some levers are equipped with swivel joints that they need to achieve the desired clearance (clearance) around while maintaining a given angle of attack of the attachment to the hub.
Together, the components of the structure set the wheel at the right point and form a rigid but movable frame attached to the hub, which not only prevents the free movement of the latter, but also creates the necessary kinematics for the moving parts of the car's suspension.
Each arm is mounted on special joints (hinges are located at both ends of the arm) and can only move vertically during the movement of the suspension. This is the only free play for them, unless a breakdown has occurred: a lever has broken, an articulated joint has loosened, or fasteners have been torn off from the body.
The multilink design is usually equipped with 4 or 5 levers(different designs require different numbers of links), allowing an independently suspended wheel to fit two important properties: Ride quality and handling. Because the suspension is rigid in lateral and horizontal (longitudinal) movement, a vehicle equipped with this suspension will not pull excessively to the side when cornering as other designs do, but it will also get smooth, independent wheel movement even over large bumps. .
It is noteworthy that the multi-link type of suspension, which is standardly associated with independent suspension, is used not only in conjunction with it. Drive axles also often use multi-link elements reinforced with an anti-roll bar, a transverse steering rod or a transverse reaction bar and, of course, springs and dampers. Solid axles on multi-link suspension are cheap, structurally simple - that's why they have been popular in the USA for so long. Americans love simple and reliable designs.
The bridge is "suspended" on a multi-link suspension
But one of the main advantages of a multilink connection is that engineers can change one of the suspension parameters without global intervention in the design and deterioration of the entire system. For example, in a double wishbone design, you always have to make changes to both suspension components, the two arms and their fasteners, whether you like it or not. Finally, the multi-link suspension is also able to keep the wheel more or less perpendicular to the road, increasing the contact surface and grip of the tire.
Formerly multi-link elastic elements were too expensive to install on regular cars(an echo of those times is perfectly visible on premium cars like , BMW, Mercedes-Benz), but in last years costs have fallen, and various interpretations of this solution have found application even in front-wheel drive hatchbacks. Usually four levers are installed at the back, the less expensive MacPherson strut is still installed in the front.
For the most part, these multi-link elements have replaced cheaper ones. trailing arms. The latter also had a progressive potential in work and increased the usable volume luggage compartment, but could not boast of high ride comfort.
Multi-link suspensions are also used in the front of cars in a scheme where one of the levers is attached to the steering rack. Rare engineering sophistication, but still occurs. Some BMWs use multi-link front suspension elements, Hyundai also tried a similar experiment with its Genesis.
In our time multi-link suspension, whose history dates back to the middle of the last century, is the most common type of mounting for the rear axle of a car. The first samples with double wishbones were installed on racing cars cooper.
Multi-link suspension - what is it?
First stock car, on which a new type of suspension was installed, was Jaguar E-type 1961 release. Over time, it was successfully used on the front axle of cars, as, for example, on some models Audi. The use of multi-link suspension gives the car an amazing ride, excellent handling and helps reduce noise.
In this design, the wheel hubs are fastened using four levers, which allows adjustment in the longitudinal and transverse planes. The multi-link design consists of the following components and parts:
- trailing arms;
- wishbones;
- stretcher;
- hub support;
- shock absorbers;
- springs.
The subframe acts as the main bearing element of the suspension, the transverse levers connected to the hub support are fixed to it, which in turn ensures its transverse position. Multi-link rear suspension, which is mounted on modern cars, consists of three or five transverse levers.
How does a multi-link rear suspension work?
Standard equipment includes top, front bottom and rear lower arm And. The transmission of the front transverse forces is carried out by the upper lever, which also serves to connect the wheel support to the subframe. The rear lower arm bears a significant portion of the weight of the car body, transmitted through the spring.
The trailing arm holds the wheels in the direction of the longitudinal axis, fastening to is carried out using a support. The opposite end of the lever is connected to the hub support. On this element are bearings and wheel fasteners. Shock absorbers and springs are in most cases installed separately.
To reduce the roll angle of the car when cornering, a multi-link suspension uses an anti-roll bar. It is attached with rubber supports, and special rods connect the rods to the hub supports. Like any other vehicle component, an independent multi-link suspension requires care and timely repair.
Independent suspension - we put it in order with our own hands
The main suspension defects that appear after passing 40,000-80,000 km are knocking and creaking, which are clearly audible even inside the car while driving on a bumpy road. What is it connected with? Knocking occurs for several reasons, they can be both serious and not very. In any case, the independent suspension must be urgently repaired, you can do it yourself if the repair consists in replacing parts or tightening threaded connections, in other cases, you can not do without visiting the service station.
The first step is to establish the cause, conduct visual diagnostics pendants. To do this, the car should be driven into a viewing hole or a jack should be used, since in an unloaded state this machine assembly will more readily show its defects. And yes, it will be more convenient for you to crawl under it. Let's say in advance if you are not a locksmith high level, then arm yourself with the manual for the device of your car, which is always included with the purchase.
Remember that knocking in the suspension area can be caused not only by a malfunction of this part, but also by a breakdown of other elements of your vehicle, such as steering rods or CV joints.
So, you are located in a convenient area for examining the front suspension. Remove the shock absorbers and carefully inspect them for cracks. Check for integrity ball joints, lever, rod, silent blocks. Pay attention to all mounting bolts and rubber seals. There should be no cracks, breaks, cuts or other damage anywhere. Carefully take a look around the perimeter of the body: where the parts touch the body, there should be a whole and intact rubber gasket.
If some “ailments” are clearly visible, evaluate your strengths, whether you can unscrew the damaged part and insert a new one, whether the assembly sequence of the damaged assembly is clear, whether the diagram in the car’s operating book is clearly shown. If you fail, or outwardly everything turned out to be intact, then it's time to visit the service station.
Diagnostics and repair of the rear suspension
Now move on to the rear suspension. There are fewer details here, but this does not mean at all that you need to be less careful. Again, we start with shock absorbers. Next, your attention should be given to traction and seals. feature rear suspension is the neighborhood exhaust pipe, which can also produce a sound similar to a broken suspension if it is loose, loose or leaning against some part, creating friction and tapping. The muffler is carefully examined, you can shake it in different sides this will probably remove the weird knock, also inspect the mount.
So, the inspection is over, the knots are tightened, partial replacement produced. Perhaps this is the "first aid" to your car. Other repairs will require more complex technical equipment and qualifications. Do not be too lazy to get under the "belly" of the car if you hear a suspicious knock. Naturally, any malfunction will be repaired at the service station, but there is a possibility that you will simply overpay for a minute replacement of the rubber gasket or for some other minor operation.
Suspension scheme multilink with A-shaped upper arm
Multi-link suspension, or Multilink, is the result of an improvement in the double-lever independent suspension of a passenger car. Unlike the standard version, the guide elements are not single V-shaped levers, but separate parts independent of each other. Their number usually varies from three to five elements. In the manufacture, the design features of the remaining suspension elements and their interaction are taken into account. Thanks to the Multilink scheme, the hub assembly gains additional attachment points and increased mobility, which significantly improves driving performance and overall vehicle handling.
History of appearance
The first car with Multilink suspension was the 1979 Porshe 928For the first time, a multi-link suspension design was applied on sports coupe Porsche 928 in 1979. In 1982, the upgraded scheme was used on Mercedes models 190. The feature of the multi-link suspension design provided the car with excellent cornering. This was achieved by creating the effect of steering the loaded rear wheel a few degrees inside the turn. Later, other automakers began to use multi-link suspension.
Elements of a multi-link suspension
Front suspension device
The Multilink front suspension consists of the following elements:
- Wishbones: provide vertical movements wheels and changing the angle of inclination of the hub assembly in the horizontal plane. Depending on the layout, the wishbones can also limit longitudinal movements.
- jet thrust: limit the movement of the hub in the longitudinal direction. They are mainly used on the rear multi-link suspension, in the front they are used to strengthen the structure.
- Springs: provide elastic connection of the suspension with the car body.
- Dampers: Designed to dampen vibrations.
- Anti-roll bar: compensates for body roll when cornering.
Front multi-link Audi suspension Q5 The presence of ball bearings in the mounts of the levers and the hub allows you to turn the wheel. upper arms are often made adjustable in length, which provides extended options for setting the parameters of the wheel alignment angles.
Rear suspension device
Rear multi-link suspension Honda Accord The multi-link suspension for the rear axle has a similar design, except for the possibility of turning the hub (with the exception of the thruster rear suspension). The most simple circuit includes two transverse and one longitudinal lower arm. Role top support performs suspension strut connected to the wheel hub. This design of the Multilink suspension is characterized by relative simplicity and availability of production.
Among various options rear multi-link suspensions, there may be suspensions with up to five levers. One of the lower ones is the carrier, holding the spring and the weight of the body. The shock absorber and spring can be installed separately or as a . An anti-roll bar also takes part in the work of the independent rear suspension Multilink.
Principle of operation
Multi-link suspension can be installed on both the front and rear axles of the car. The upper and lower arms, independent of each other, are fixed on the body on one side and on the wheel hub on the other. The peculiarity of this suspension is that the wheel hub is able to change its position in the horizontal plane, improving the smoothness of the ride on uneven surfaces and increasing the vehicle's stability when cornering.
Animation of the Multilink five-arm suspension (top view) Animation of the Multilink five-arm suspension (rear view)
Advantages
Compared with a double wishbone design, a multi-link suspension has the following advantages:
- better stability car;
- excellent smoothness of the course;
- excellent cornering;
- independent transverse and longitudinal adjustment of the hub position angles.
Flaws
Cons due to design features front suspension Multilink:
- bulkiness;
- complexity and high cost of production;
- less reliability.
The use of multi-link suspension
The disadvantages of using the Multilink scheme for the front suspension in the form of an increase in the cost of the car and expensive repairs are justified only during production expensive cars. Additional arms of complex design with ball joints increase the cost of the entire suspension scheme. It is also necessary to provide for a complex structure of interaction of elements with greater mobility, especially when turning the wheel. In this regard, the front suspension of the Multilink type is not used in the bulk cars, in the production of which the main criteria remain low price, reliability and maintainability.
2015 Lexus RC rear multilink diagram
Multi-link suspension for rear wheels received most widespread. Compared to the complicated design for the front axle, where it is necessary to rotate the hub assembly, the cost of manufacturing the Multilink rear suspension is significantly lower. The only expensive element is a massive load-bearing lower arm that takes the main load. The rest of the rods and levers serve only as guides.
Scheme of the rear multi-link suspension Honda Civic Multi-link suspension can be installed on mono-drive and four-wheel drive vehicles. Currently, it is widely used in the production of both passenger cars and crossovers. The progressive design combines the advantages of a two-lever scheme - stability and smoothness, improving them thanks to the separate arrangement of the guide elements. Multilink suspension allows you to increase the controllability of the car, as well as to implement it best grip with pavement.
