Generally speaking, automobile suspension systems are divided into two types: dependent suspension and independent suspension. The wheels of the dependent suspension are installed at both ends of the integral axle. When one wheel jumps, the other wheel also jumps accordingly, making the whole body vibrate or tilt; The independent suspension axle is divided into two sections, and each wheel is independently installed under the frame through a coil spring. When one wheel jumps, the other wheel is not affected, and the wheels on both sides can move independently, which improves the stability and comfort of the car.
Because modern people have higher and higher requirements for comfort and handling stability, dependent suspension systems have been gradually eliminated. Independent suspension system is widely used by automobile manufacturers because of its good wheel contact, which greatly improves ride comfort and handling stability, free movement of left and right wheels, great freedom between tires and ground, and good vehicle handling performance. Common independent suspension systems include multi-link suspension system, McPherson suspension system, candle suspension system and trailing arm suspension system.
First, let's take a look at the most common McPherson and candle hanging systems. Both of them are similar in appearance and are the combination of spiral spring and shock absorber, but there are significant differences due to different structures. The candle shape is named after the suspension whose wheels move along the direction of the main pin shaft. Its characteristic is that the position of the kingpin and the positioning angle of the front wheel do not change with the wheel jumping up and down, which is beneficial to the maneuverability and stability of the automobile. McPherson suspension is composed of articulated strut and lower cross arm. The shock absorber can also be used as the steering kingpin around which the steering knuckle can rotate. Its characteristic is that the position of the kingpin and the positioning angle of the front wheel change with the up-and-down jumping of the wheel, which is just the opposite of candle hanging. This suspension has the advantages of simple structure, compact layout, small front wheel alignment change and good driving stability. Therefore, McPherson suspension is the most widely used independent suspension in automobiles.
About McPherson suspension, there is still such a record in the history of the car world. Mcpherson is an American from Illinois, born in 189 1. After graduating from college, he worked in aero-engines in Europe for many years, and 1924 joined the Engineering Center of General Motors. In 1930s, the Chevrolet division of General Motors wanted to design a real compact car, and the chief designer was McPherson. He is very interested in designing small cars. The goal is to control the mass of this four-seater car within 0.9 tons and the wheelbase within 2.74 meters. The key to design is suspension. McPherson changed the front suspension mode of leaf spring and torsion bar spring that prevailed at that time, and creatively combined shock absorber and coil spring and installed them on the front axle. Practice has proved that this kind of suspension has simple structure, small occupied space and good maneuverability. Later, McPherson jumped to Ford. 1950 Two cars produced by Ford's British subsidiary were the first commercial vehicles in the world to use McPherson suspension. McPherson suspension is praised as a classic design by experts because of its simple structure and superior performance.
Let's look at the trailing arm suspension system. The trailing arm suspension system is a suspension system specially designed for rear wheels. European cars such as Peugeot, Citroen and Opel prefer to use this suspension system. The structure of trailing arm suspension is too complicated and professional, so it will not be introduced here. You only need to know that the biggest advantage of the trailing arm suspension system is that the distance between the left and right wheels is large, the camber angle of the car body is unchanged, and the shock absorber has no bending stress, so the friction is small and the ride comfort is good. When braking, the rear wheel suspended by the trailing arm will sink to balance the car body. Its disadvantage is that it cannot provide accurate geometric control, so some car manufacturers will combine some connecting rods to solve it, forming a complex multi-link suspension.
Finally, let's look at the multi-link suspension system, which is divided into 5-link rear suspension and 4-link front suspension system. As the name implies, the 5-link rear suspension system consists of 5 links, namely the control arm, the rear positioning arm, the upper arm, the lower arm and the front positioning arm, wherein the control arm can adjust the toe-in of the rear wheel. The advantages of connecting rod suspension are simple structure, light weight and small space occupied by suspension system. 5. The connecting rod rear suspension can achieve the best position of the caster angle of the kingpin, greatly reducing the front and rear forces from the road surface, thus improving the ride comfort and comfort during acceleration and braking, and ensuring the stability of straight-line driving, because the lateral deviation of the wheel caused by the tension or compression of the coil spring is very small, and it is not easy to cause non-straight-line driving. When the vehicle turns or brakes, the 5-link rear suspension structure can make the rear wheel form a positive toe-in, which improves the control performance of the vehicle and reduces the understeer. At the same time, the compact structure increases the space of the rear seat and luggage compartment. This kind of suspension is popular because of its obvious advantages and easy adjustment. The brand-new 4-bar front suspension system is mostly used in luxury cars, which skillfully separates traction, braking force and steering force through kinematics principle, and gives the vehicle accurate steering control at the same time. The four-link suspension system can be seen on Audi A4, A6 and China cars.
Therefore, when car owners buy light vehicles, the best suspension system should be front wheel McPherson or candle suspension system and rear wheel trailing arm suspension system. It is best not to use dependent suspension. Needless to say, when buying a high-end car, choose a 4-link suspension system. There are three basic forms of suspension system without suspension, namely dependent suspension, independent suspension and semi-independent suspension in between.
Because the dependent suspension is directly and rigidly connected to the wheels on both sides with a rod, the impact and vibration of one wheel will inevitably affect the other wheel, so naturally it will not get better handling stability and comfort. At the same time, due to the interaction between the left and right wheels, it is easy to affect the stability of the car body and turn over when turning. At present, this structure is adopted and popular by Ruifeng.
The solidity of the independent suspension chassis is very obvious. Because the wheels on both sides of the car with independent suspension are independently connected to the car body, from the use process, when one wheel is impacted and vibrated, the impact force can be absorbed by the elastic element itself, and this impact force will not affect the other wheel, so that the manufacturer can make a reasonable configuration of the car in three aspects: ride comfort, stability and handling stability through appropriate adjustment at the beginning of car design. Grace Brilliance has adopted this structure, and this chassis is basically used in automobile design, which makes passengers feel the comfort of the automobile and ensures that drivers and passengers have comfortable enjoyment during long-term driving, and will not suffer from the limping caused by the light passenger chassis.
Semi-independent suspension is actually a special form of non-independent suspension, because its wheels on both sides are also directly connected by a bar, but the material of this bar is not completely rigid, but has good torsional characteristics. When one wheel is impacted, the impact on the other wheel is not as strong as that of the dependent suspension, but it is also difficult to reach the level of the independent suspension. In fact, this form is also considered and adopted by automobile manufacturers from the perspective of cost saving, and Buick GL8 also adopts this structure.
Suspension can be divided into independent suspension and dependent suspension according to structural characteristics.
Dependent suspension connects the left and right wheels into a whole through an axle, and then connects the whole axle with the frame or body through two suspension springs.
Non-independent suspension is mostly used for the front and rear wheels of trucks and buses. Passenger cars are mostly used for rear wheels for comfort and high-speed driving stability, and the front wheels are generally not used.
The dependent suspension with leaf spring has simple structure and low cost, and the deflection angle of leaf spring is very small when turning. Except for non-independent suspensions with longitudinal leaf springs, it is not necessary to install guide rods, and other non-independent suspensions with spiral springs and air springs (mainly used for buses) must be equipped with guide rods that can restrain axle movement.
The left and right wheels of independent suspension are not connected by an integral axle, and the wheel movements on both sides are irrelevant. This type of suspension has the following advantages:
① It lightens the weight under the spring of automobile suspension and improves the comfort of passenger cars.
② Very soft springs can be installed to improve the ride comfort.
③ It can prevent the occurrence of front wheel shimmy.
(4) For the rear wheel of FR car, the differential can be fixed on the side of the car body to reduce the height of the floor and rear seat from the ground and the center of gravity of the car.
Contrary to the above advantages, this suspension type has the following disadvantages:
① The independent suspension has complex structure and high manufacturing cost.
② car maintenance is difficult.
(3) The front wheel alignment and wheel spacing often change when the car is driving, so sometimes the tires are seriously worn.
According to the independent characteristics of independent suspension, it is mostly used on the front and rear wheels of passenger cars and the front wheels of medium and small trucks.
There are many structural types of independent suspension, among which double rocker arm type, candle type, swing arm type and semi-delayed swing arm type are widely used.
Add some more knowledge:
Then what is the torsion beam rear suspension?
If the dependent hard-axle suspension does not use leaf springs (its particularity lies in that it is both an elastic element and a guiding structure), it also needs a separate guiding structure, and the simplest one is the trailing arm, so don't confuse the independent trailing arm suspension with the dependent trailing arm suspension.
In fact, we can get a special suspension by using deformable beam instead of the hard shaft of dependent suspension. You can think of it as a dependent suspension, but the axle here is not rigid. You can think of it as an independent suspension, because this non-rigid shaft can actually be regarded as a special anti-roll bar. The installation position of its "shaft" can be changed, and the specific form also has many changes. A typical example is the torsion beam commonly used by the public. This kind of suspension is usually called semi-independent suspension, which is actually inaccurate.
Structure and characteristics of rear rocker arm independent suspension
The rear rocker arm independent suspension is mainly used as the rear wheel suspension of the automobile, and a swing arm swinging longitudinally is arranged in front of the rear wheel. Swing arm is divided into single swing arm and double swing arm composed of two swing bars side by side. The suspension spring is directly installed on the swing rod with a spiral spring.
When the rear swing arm independent suspension works, the camber angle and track distance of the wheels are unchanged, only the wheelbase of the car changes slightly, so this suspension can also be used for the front wheels. However, when the front wheel adopts this suspension, the nodding angle of the car increases when braking. For the rear single swing arm suspension, its wheel inclination angle also changes, which is an undesirable problem for the front suspension, so the rear single swing arm suspension is mainly used as the rear suspension.
What rear suspension does Passat B5(GP) use?
The answer is the torsion beam rear suspension!
The public chose it because:
First, the structure is simple and the cost is low;
The second is to help Passat get more rear seat space and trunk volume with shorter vehicle length (original version); Third, the development of this suspension is inseparable from the public, and the public has a good impression on it.
the problem is
However, is the torsion beam rear suspension independent or not?
Why did Passat (B6) give up the torsion beam rear suspension?
For ordinary small cars, this kind of rear suspension keeps the advantage of small space occupied by the trailing arm.
For sports cars, it is easy to provide enough handling (the price is really hard).
So at present, some small cars still choose this kind of suspension. However, the shortcomings of the (semi-) trailing arm rear suspension have never been completely overcome.
If the suspension type is determined, its main characteristics will not change greatly, but the specific details can still have a considerable impact on the performance. For example, the torsion beam rear suspension is not technically advanced (it is actually backward at present), but the public's training of PSTB5 suspension is still excellent.
Now we know why Passat (B6) abandoned torsion beam rear suspension and switched to multi-link independent rear suspension.
Because: 1. Non-independent suspension such as rotating beam rear suspension can never achieve the balance between maneuverability and comfort like multi-link independent rear suspension.
Second, the public's position on themselves is higher than before, and the requirements for maneuverability and comfort exceed the cost control, and the corresponding price has also increased.
Third, we should keep up with the trend of technological development. The public is not that stupid.
I'd like to ask about the conditions for applying for technician.
First, the applicant
Who is engaged in or ready to engage in te