What are the rubber bushings in the car suspension for?

In fact, most of the rubber parts on automobiles are inseparable from the original intention of "buffering vibration isolation". For example, the invention of tires - tires were first used on bicycles. The first bicycles had no tires, and the road conditions in those days were very poor, either unpaved roads or stone roads, on which bicycles were driven. It is very uncomfortable for the cyclist, and it also limits the speed of the ride. According to legend, during a folk bicycle race, a contestant saw a rubber hose for irrigation in his garden before the race, and tied it to his bicycle wheel on a whim. Although this pair of "earth-made" tires were not as good as the later pneumatic tires, they were still effective, helping the player win the championship in one fell swoop and making everyone follow suit.

The bushings on the suspension, and even the invention of the powertrain suspension, are based on the same starting point, nothing more than to make people more comfortable.

For suspension, the source of vibration is the road surface. The undulations of the road surface act on the wheels and are transmitted to the body through the suspension. In the suspension, there are two transmission paths of vibration: one is the spring and shock absorber, and the other is the control arm of the suspension. In terms of isolation of vibration, no matter how well the springs and shock absorbers are done, they cannot stop the vibration from going the other way, so there is something like a rubber bushing.

With the addition of bushings, derivatives were also brought. It not only absorbs and isolates vibration through deformation when the road is uneven, but also deforms when steering, braking, acceleration, etc. are dynamic changes. The deformation at this time brings two effects: one is the suspension The deformation characteristics of the frame, that is, the "C" characteristics in the K&C characteristics (about this, I have described in more detail in my previous articles); the second is to change the frequency characteristics of the suspension, or the response to driving operations Performance.

Although these two derivative effects were not the original intention of the bushing, they were gradually used by engineers. For example, when our car drives over the speed bump, the deformation of the bushing can make the wheel back slightly and the impact will be less.

So why are there no bushings on many race cars? What if there is no bushing?

First of all, people will feel uncomfortable when they are shaken. Larger road undulations can still be dealt with a lot by the springs and dampers, but the tingling vibrations that make people feel numb are very "honest" transmitted to the body.

Second, it will be very noisy. All kinds of noises, such as "crunching" and "crackling", will appear, and even the interior will become looser under long-term vibration.

Then again, the life of the suspension will be much shorter. Cars with rubber bushings can withstand 100,000 kilometers of durability, but joint bearings (commonly known as "fish eyes" or "ball joints") can't. No racing car needs to be replaced with "fish eyes" every 100,000 kilometers.

Eventually, the car will become difficult to drive. Of course, the "difficult to drive" here is aimed at ordinary consumers, and for racers, they can't wait. In a car without a bushing, if the steering wheel is turned a little faster, it will feel like being kicked hard from the side, and the response of the car will become much more direct and much faster. For ordinary civilian use, we don't want the car to respond so fast, but it is appropriately slower to make people feel more comfortable and relaxed.

According to legend, Hamilton can operate the steering wheel at a frequency of 5Hz, which is about 10 changes of direction per second, and it is still effective control. Ordinary people's driving usually does not exceed the 2Hz action frequency. The response of the car is too fast and the tires are direct, and it will be difficult to control like a fierce horse. However, your arsenic and my honey are nightmares for ordinary people, but they are the yearning of professional players.