More pictures to understand how car suspension works and solve my years of confusion!

Crazy Mechanical Control Issue 500 The suspension system is a vehicle system composed of springs, shock absorbers and connecting rods, used to connect the vehicle and the wheels. The suspension system makes the vehicle's handling and braking suitable for good dynamic safety and driving pleasure, maintains the comfort of the car owner and isolates appropriate road noise, bounce and vibration.

Traces of leaf springs have appeared in ancient Egypt. Ancient weapons experts used curved leaf springs to strengthen siege weapons, and later the leaf springs used in catapults were more sophisticated and could last for years. At that time, springs were not made of metal, but hard branches were used as springs, just like making bows.

In the early 19th century, most British carriages were equipped with springs. Wooden springs were used for shock absorbers in light carriages, while larger carriage springs were made of steel. These iron springs are made of mild steel and are usually stacked in multiple layers to create leaf springs.

In its early development, the automobile was likened to a horse-drawn carriage that provides its own power for propulsion. But relatively speaking, the carriage is designed to travel at low speeds, and its suspension is not suitable for the high speeds generated by internal combustion engines.

In 1903, the German Mors Automobile Company installed shock absorbers on vehicles for the first time. In 1920, the Leyland Automobile Company added a torsion bar device to the suspension system. In 1922, Lancia Lambda pioneered the use of independent front wheel suspension. This suspension system became popular in vehicles sold after 1932.

Suspension stiffness (or spring stiffness) is one of the factors used to set the vehicle height or its positioning when the suspension is telescopic. Vehicles carrying heavy loads are often paired with stiffer suspension to offset the extra weight load that might otherwise crush the vehicle on the way (or when bouncing).

Generally speaking, vehicles that often carry heavy weights should be equipped with harder springs whose spring stiffness is close to the upper limit of the vehicle weight, so that the vehicle can carry cargo normally and drive smoothly. Driving an unladen cargo truck can be uncomfortable for passengers because the ride is too stiff due to the high spring rates associated with the vehicle's weight.

Spring stiffness is a ratio that measures the resistance of a spring when it is compressed or stretched when deflected. According to Hooke's law, elastic strength increases as deflection increases. Simply put, this phenomenon can be described by the following formula: F=kx

Among them, F is the force of the spring; k is the stiffness of the spring; x is the displacement during static equilibrium.

Let’s talk about five commonly used car suspensions: MacPherson suspension, double wishbone suspension, multi-link suspension, torsion beam suspension and integral axle suspension.

MacPherson suspension is a suspension form composed of a twisted sliding column and a lower wishbone. The shock absorber can also serve as the steering kingpin, and the steering knuckle can rotate around it. The characteristic is that the position of the king pin and the positioning angle of the front wheel change with the up and down movement of the wheel. This kind of suspension has a simple structure, compact layout, small changes in front wheel positioning, and good driving stability. Therefore, the most commonly used independent suspension in cars is MacPherson suspension.

For many front-engine and front-wheel drive vehicles, most of the space in the front part of the car is used to arrange the horizontal engine and gearbox, leaving little space for suspension, so the Mai The advantages of the Ford Suspension's small size and light weight will be very obvious.

Double wishbone suspension is composed of two A-shaped arms of different lengths and a shock absorber that acts as a pillar. The upper and lower A-arms are connected to the upper and lower steering knuckle arms on the wheel through ball joints respectively, while the series-connected shock absorbers and coil springs act as pillars and steering kingpins, and their upper ends are connected to the subframe. , the lower end is connected to the lower swing arm. The upper and lower A-arms are responsible for absorbing lateral forces during steering, while the strut shock absorbers are only responsible for supporting the weight of the body and controlling the up and down bounce of the wheels.

Double wishbone suspension is arguably the strongest independent suspension.

We all know that triangle is the most stable geometric shape. The upper and lower A-arms of the double wishbone suspension have a stable structure similar to a triangle. Not only does it have sufficient torsional strength, the upper and lower A-arms have good resistance to lateral forces. In addition, the four positioning parameters of the wheel are precisely adjustable: front and rear camber, front wheel toe, kingpin inclination and kingpin caster, which can improve vehicle handling. If used on an SUV, it can also cope with the huge impact caused by extreme off-road conditions.

Multi-link independent suspension can be divided into multi-link front suspension and multi-link rear suspension systems. The front suspension is generally a 3-link or 4-link independent suspension; the rear suspension is generally a 4-link or 5-link rear suspension system, of which the 5-link rear suspension is widely used. Its five connecting rods are: main control arm, front positioning arm, rear positioning arm, upper arm and lower arm, which produce forces in various directions.

The multi-link suspension can achieve the optimal position of the kingpin caster angle and greatly reduce the front and rear forces from the road surface, thus improving the smoothness and comfort during acceleration and braking, while also ensuring Straight-line driving stability, because the lateral deflection of the wheel caused by the tension or compression of the coil spring is very small, making it difficult to cause non-straight driving.

However, multi-link suspension has a complex structure, high cost, many parts, and time-consuming assembly. In order to achieve the durability of a non-independent suspension, it is always necessary to keep the connecting rods from deforming or shifting. The use and structural optimization will also be very particular. Therefore, the main pursuit of multi-link suspension is to pursue excellent handling and driving comfort, but it is not suitable for all situations.

Torsion beam suspension is a type of car rear suspension device. A balance bar is added to the torsion beam non-independent suspension to tilt the wheels and keep the vehicle stable. Its working principle is to install non-independently suspended wheels on both ends of an integral axle, so that when one wheel jumps, it will affect the other wheel to jump accordingly, causing the entire vehicle body to vibrate or tilt.

Cars using this kind of suspension system generally have poor stability and comfort, but due to their simple structure and large load-bearing capacity, this suspension is mostly used on trucks, ordinary buses and some other special vehicles.

Integral axle suspension means that there is an integral axle structure connecting the two wheels. The axle cannot be disconnected, and the two wheels on the same axle have no relative movement. For a drive axle, it is mainly composed of a differential housing, axle tube, axle shaft, bearings and other parts. For a non-drive axle, the overall axle has a simpler structure and is now mostly used in trucks.

Due to the compromise between comfort and road performance, there are not many models using integral axle suspension now, but this does not negate its practicality and status in the minds of off-road enthusiasts, because The integral axle suspension has a simple structure and is easy to maintain and modify, so models that emphasize load-bearing and off-road use will continue to use this suspension.