Technology Sharing

한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina

1. Composition and function of automobile suspension

Automobile suspension (also called suspension) is an important mechanism connecting wheels and car body, which mainly supports and reduces vibration of the car body. The quality of suspension system directly affects the driving performance and ride comfort of the car.

组成部分：典型的悬挂系统结构主要包括弹性元件、导向机构以及减震器等部分。
1

1. Elastic element: This is the basic part of the suspension system, usually refers to the coil spring. It mainly bears the vertical load and can alleviate and suppress the impact of uneven roads on the vehicle body. Elastic elements are in the form of leaf springs, air springs, coil springs and torsion bar springs.
2. Guide mechanism: The force transmission device can be classified into this category. It includes the upper and lower swing arms of the frame, the fork steel frame, the steering knuckle and other components, which are mainly used to transmit longitudinal force, lateral force and torque, and ensure that the wheels have a certain relative motion law with respect to the frame.
3. Shock absorber: This refers to the hydraulic shock absorber, whose main function is to accelerate the attenuation of the vibration of the vehicle body. The shock absorber is the most sophisticated and complex mechanical part in the suspension system.
   In addition, some car suspension systems are also equipped with a lateral stabilizer bar. The function of this device is to improve the lateral stability of the car while driving.

悬挂的作用:	支撑、减振
1

Its main function is to transfer the force between the wheels and the frame, cushion the impact force transmitted to the frame or body by uneven roads, and attenuate the vibration caused thereby to ensure that the car can run smoothly.

2. Classification of Suspension

汽车悬挂可以按多种形式来划分，按导向机构划分可分为独立悬挂和非独立悬挂两大类；
按控制方式划分可分为被动悬挂、主动悬挂和半主动悬挂三大类。
1
2

Independent suspension and non-independent suspension

Independent suspension can be simply understood as there is no hard axle between the left and right wheels for rigid connection, and all the suspension components of one side of the wheel are only connected to the car body. When the car is driving on an uneven road, the wheels on both sides of the independent suspension can move independently, thereby reducing the vibration of the frame and body. Independent suspension reduces the unsprung mass and can reduce the impact load on the car, thereby greatly increasing its average driving speed.

The wheels on both sides of the non-independent suspension together with the integral axle are suspended on the frame or body through elastic elements. When one wheel is impacted and bounces, the other wheel will also be affected. Its smoothness and comfort are poor, but its structure is simple and has a large load-bearing capacity.

Common independent suspensions include McPherson suspension and double wishbone suspension, improved semi-independent suspensions include torsion beam suspension, and independent suspensions include air suspension. Their structural diagrams can be found in the link at the end of the article.

Passive suspension, active suspension and semi-active suspension

With the development of electronic control technology, the electronic control technology of the suspension system has further developed. The difference between passive suspension, active suspension and semi-active suspension lies in the degree of working state of the electronically controlled suspension.

The passive suspension system is a mechanical suspension system without electronic control, and the suspension performance can only be adjusted by changing the spring stiffness and shock absorber damping.

Active suspension can adjust the stiffness and damping of the suspension in a timely manner according to the vehicle's motion state and road conditions, so that the suspension system is in the best vibration reduction state, so that the vehicle will have good comfort under various road conditions. Active suspension directly replaces the spring element and damping shock absorber element in the passive suspension with an actuator, generally including a control mechanism and an actuator. The control mechanism is a closed-loop control system composed of an ECU (electronic control unit) and sensors. It monitors road conditions, the vehicle's operating status and the driver's needs through sensors, and sends control signals to the actuator (air spring, power source, etc.) in real time according to the set control rules to adjust the suspension stiffness and damping coefficient.

Semi-active suspension is a type of suspension between active suspension and passive suspension. It usually does not change the suspension stiffness but only changes the suspension damping to adapt to different road conditions and driver needs.

refer to

The pictures and text show how the car suspension works and its mechanical principles, which are intuitive and easy to understand!