What is suspension?

1. Overview

MacPherson suspension A typical structure of an elastic suspension member, the guide mechanism and a damper and other components, as well as the structure of the individual buffer block, stabilizer and the like. Another elastic member in the form of leaf springs, air springs, coil springs and a torsion bar spring or the like, to use more modern car suspension coil spring and a torsion bar spring, limousine individual air spring is used.

The suspension is important in automobile assembly, it is the frame and wheels elastically linked to the relationship of the plurality of performance cars. From the outside, only by some car suspension rod, tube and springs, but do not think it is very simple, opposite a car suspension is more difficult to achieve the perfect vehicle assembly requirements, because both suspension to meet the comfort requirements of the car, but also to meet the requirements of its handling and stability, and these two aspects are contradictory to each other. For example, in order to achieve good comfort, it requires a significant buffer vehicle vibration, the spring must be designed so soft, but soft spring but it is easier to make cars brake happen “nod” to accelerate “rise” as well as serious adverse events roll around the tendency is not conducive to steering a car, easily lead to vehicle handling and instability.

2, in the form of

non-independent suspension

Santana suspension non-independent front suspension 2000 structure is characterized by both sides of the wheel connected by a unitary frame, along with the wheel axle with suspended by the elastic suspension of a vehicle body frame or below. Axle suspension has a simple structure, low cost, high strength, easy maintenance, small changes in wheel alignment in road advantages, but because of its comfort and steering stability are poor, substantially no longer used in modern passenger cars , the use in trucks and buses.

independent suspension
independent suspension on each side of the wheel is individually suspended in the frame or body by the elastic suspension below. Its advantages are: light weight, reducing the impact received by the vehicle body, and improves the adhesion of the ground wheels; available small soft spring stiffness,Improve the comfort of the car; the engine can be lowered position, the center of gravity is reduced automobile, thereby improving the running stability of the vehicle; the left and right wheels individually beating, independent of each other, can be reduced and vibration of the vehicle body is inclined. However, there is a complex structure independent suspension, high cost and inconvenience of maintenance shortcomings. Modern cars are mostly independent suspension, according to the different structure, can be divided into independent suspension wishbone, trailing arm type, multi-link, candle McPherson suspension and the like.

wishbone suspension
refers to a suspension wishbone independent suspension of the wheels pivot in the vehicle transverse plane, according to the amount of traverse is divided into the number of cross-bis arm and a single arm suspension.

Suspension damper and a coil spring Single Arm simple structure, high roll center, has strong advantages in roll resistance. But with the increased speed of modern cars, the roll center tread too high will cause large changes in wheel hop, increased tire wear, and around a sharp turn at the wheel vertical force transfer is too large, leading to the rear wheel camber increases. Reduces cornering stiffness of the rear wheel, resulting in a high-speed tail flick severe conditions. Single wishbone independent suspension at the rear suspension multi-application, but can not meet the requirements of high speed, small current applications.

double wishbone independent suspension according to whether the upper and lower arm of equal length, is divided into equal length double wishbone unequal length and type two double wishbone suspension. Isochronous long double wishbone suspension wheel beating down, the kingpin inclination can be maintained unchanged, but the track changes (and similar single transverse arm), resulting in severe tire wear, is now rarely used. For unequal length double wishbone suspension, may be suitably selected to optimize the length of the upper and lower wishbone, and reasonable arrangement, it is possible to track and wheel alignment parameters are within the acceptable limit, ensure the car good driving stability. Currently unequal length double wishbone type suspension has been widely used in the front suspension of the car, sports car and part of the rear car also be employed which – suspension structure.

The multi-link suspension
suspension is a multi-link suspension (3-5) combined rod member the change in position of the wheel suspension control. The multi-link enables the wheel about the longitudinal axis of the car at an angle to the pivot axis, and the longitudinal arm is a cross arm compromise,Suitably selected car longitudinal axis of the arm into the line angle, can be obtained in varying degrees of advantage wishbone type suspension trailing arm, to meet different performance requirements. The main advantage of the multi-link suspension is that: the wheels and track runout toe little change, regardless of the car is driving, the braking state as intended by the driver can be smoothly turned, its shortcomings are cars when the high-speed shaft swing phenomenon.

The trailing arm suspension
The trailing arm type independent suspension refers to suspension structure of the wheels pivot in the longitudinal plane of the car, is divided into single and double longitudinal vertical arm arm in two forms. Angle will have a greater change in the kingpin single trailing arm type suspension when the wheel up and down, so no single trailing arm suspension on the steering wheel. Two pairs of trailing arm type suspension arm is generally made of equal length, forming a parallel four-bar linkage, so that, after the up and down when the wheel angle kingpin remains unchanged. Double trailing arm suspension on a multi-application in the steering wheel.

candle suspension
Structural features candle wheel suspension is moved along the main line pin rigidly fixed to the frame. Advantage is that the candle suspension: suspension when deformed, the positioning angle of the kingpin does not change, only the track, wheelbase slight change, and therefore is particularly advantageous for steering vehicle steering stability and driving stability. But the candle suspension has a big drawback: when the lateral force is the car running will all be set by the kingpin kingpin sleeve bear, resulting in increased friction between the sleeve and the kingpin, wear is also more serious. Candle type suspension has been applied much.

McPherson suspension
McPherson suspension wheel is slidable along a suspension kingpin, but not identical with candle-type suspension, it the kingpin can swing, McPherson-type suspension is combined with a swing arm type suspension candle. Compared with the double wishbone type suspension, the suspension is McPherson advantages: a compact configuration, when the front wheel alignment wheel hop small variations, good steering stability, coupled with the lifting of the arm, to engine and steering system arranged convenience; compared with candle-type suspension, the lateral force its spool to have been greatly improved.

Suspension McPherson front suspension and more applications on small cars, the Porsche 911, the front suspension made Audi, Santana, Xiali, Beverly and other cars are McPherson independent suspension . While McPherson suspension does notIt is the highest-tech suspension structure, but it is still one kind of independent suspension durable, has a strong ability to adapt to the road.

active suspension
active suspension developed in the past ten years, a new type of computer-controlled suspension. It brings together the technical knowledge of mechanics and electronics, it is a more complex high-tech devices. For example, the active suspension apparatus French Citroen Sang Diya, the hub is a vehicle suspension system microcomputer, five types of sensors on the vehicle speed are respectively transmitted to the microcomputer of the suspension, the front wheel brake pressure, speed of movement of the accelerator pedal depression, amplitude and frequency data in the vertical direction of the vehicle body, the steering speed and steering wheel angle. Computer continuously receives these data and compared with a predetermined threshold value, select the appropriate suspension state. Meanwhile, the microcomputer independent control actuators on each wheel only, by controlling the changes in the hydraulic shock absorber generates tic, which can produce suspension movement to meet the requirements at any time on any wheel. Therefore, Sang Diya car a wide range of driving mode selection, as long as motorists pulled the deputy located on the dashboard of a “normal” or “sport” button, the car will automatically set the optimum suspension state, in order to most good comfort performance.

having a control body movements active suspension function. When the inertia brake or turn causes deformation of the spring, an active suspension force is generated against the inertia force with reduced change in body position. For example, paragraph 2000 Mercedes-Benz CL coupe, suspension sensor will immediately detect the tilt and lateral acceleration of the vehicle body when the vehicle is cornering. Computer according to information from the sensor, compared with the calculated threshold value set in advance, immediately determine what position on how much load is applied to the suspension, the inclination of the vehicle body is minimized.

3, the suspension system

The multi-link suspension configuration diagram (Honda Accord) is a suspension frame (or monocoque) and the axle (or wheel) general term for all the means of the force-transmitting connection between. An elastic member generally consists of three parts, and the shock absorber guide mechanism.

The front suspension system
Currently the front suspension are substantially independent suspension system, i.e., leftRight two wheels are each independently suspended by means connected to the vehicle body, which means can be independently up and down. The suspension system link mechanism and a spring, a shock absorber triangular, quadrangular or other shape connection in a fixed relative position of the wheel and the vehicle body, the wheel under the action of the spring can be moved up and down relative to the body. The most common double-wishbone and MacPherson (also known as the strut swing arm).

double wishbone type suspension by a short length on the lower two wheel arm connected to the vehicle body, two arms are not truly horizontal rod, but substantially similar letters Y or C, and the designed both to increase the strength and improve the positioning accuracy, but also for the installation of the damper and the spring space and leave the installation location. At the same time, the length of the longer lower arm, and the wheel center is substantially at the same level, the aim is to wobble in the wheel hop traverse lead, will not produce much deflection angle, also to ensure that the wheels dip will not change much. This structure is more complex, but durable, while small shock load, a long life.

strut arm type suspension structure is relatively simple, only the lower arm and a shock absorber – spring means sets two wheels connected to the vehicle body, it has the advantage of simple structure, light weight, small footprint , the vertical stroke length and the like. The disadvantage is a shock absorber – spring group acted as kingpin, it is also subjected to lateral forces acting on the wheel surface, and therefore greater resistance during vertical movement, also increases the wear and tear. And when a sharp turn, due to the roll of the vehicle body, left and right wheels also incline outward, understeer occurs, the softer the greater the tendency of the spring.

After the suspension

after the

type suspension system for the front suspension to be more than one reason is the different embodiment of the drive axle determines the presence or absence of , also related to body weight. There are two kinds of link type and swing arm.

Active hydraulic suspension FR-link in the main drive system, and the integrated right and left rear axle case (rigidly connected to the intermediate differential) is used, in the past use more leaf springs supporting the vehicle body, now of improving driving comfort considerations, the use of a multi-link and the rear swing arm to say, good ride and using a coil spring. Each link in the left and right sides of a pair of divided upper link and lower link, the lateral force transmitting a machine (vehicle drive force)Configuration, and then usually with a lateral thrust rods together form five-link. Lateral thrust rod connected at one end of the vehicle body, one end connected to an axle, which purpose is to prevent the axle (or body) lateral traverse. When the axle moves up and down due to turbulence, the transverse contacts and the thrust rod to be connected to the vehicle body painting arc axis exercise, if the pivot angle over the General Assembly significant lateral relative movement between the axle and the vehicle body, the lower arm similar principles, but also the transverse thrust rod designed to be relatively long to reduce the pivot angle.

-link suspension is formed integrally with the axle, the large mass of the lower spring, and the left and right wheels can not move independently, so that an uneven surface facing the impact energy generated in the vehicle body is relatively large, ride comfort is poor. Thus using the arm embodiment, this embodiment is merely an intermediate axle differential is fixed, the left and right axle universal joint is provided between the differential and the wheels, and its swing center, between the wheel and with the frame the connecting arm Y type. “Y” is rigidly connected to one end of the individual wheels, and the other two end points connected to the frame and forms a rotation axis. Depending on whether the rotation axis is parallel to the axle, the swing arm suspension arm is divided into all-drag type drag-type and semi-arm, parallel dragging the whole formula, called semi-drag type non-parallel.