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Basic knowledge of automobiles (15) What is four-wheel alignment for?

All right

Straight to the point

In this issue, let's talk about four-wheel alignment

When I first heard the concept of "wheel alignment".

I thought it would work like a table leg

Let the four wheels be on the same plane, and they can all exert the upper force

This led to a friend of mine at the time making fun of me for half a year

Wheel alignment

In fact, it is to adjust some of the angle parameters of the wheel

The main purpose is to solve the problem of tire eating and tire deviation

so

What are the main parameters of the four-wheel alignment?

Kingpin caster

Kingpin camber

Camber of the front wheels

Toe-in of the front wheels

Let's explain them one by one

Kingpin caster

Quite simply, literally

That is, the kingpin of the wheel will have a backward inclination

Think about it, that fork on the front wheel of the bike

Is it also tilted backwards?

This angle of inclination

It is so that the front wheels can automatically return to the center

Especially at high speeds

Ability to keep the vehicle in a straight line

Otherwise, it is necessary to constantly correct the direction

Then the vehicle will not be able to drive smoothly

So when riding a bike

After the speed of the car is up

Some people are able to "make a big deal"

It is the balance that is provided by this angle

Generally speaking

The more you lean back

The greater the positive force

Correspondingly, the steering wheel will also be heavier

And it will also be more fetal

Kingpin camber

Also literally

The wheel kingpin is tilted inward

I believe many cardholders will find out

When parking, if the steering wheel is facing one side, it is killed

Then the two wheels will tilt towards the inside

This is actually because the kingpin of the wheel is inclined inward

The wheels rotate around the inclined kingpin

So the wheels are naturally also tilted

What happens when the wheels are tilted?

It's like lifting the table up a corner

Let go of your hand and it will fall down automatically and return to its original shape

So

The inward tilt of the kingpin is also used to allow the front wheels to automatically align

moreover

This positive force has nothing to do with the speed of the vehicle

It goes along with the caster of the kingpin

Keep the vehicle in as straight as possible

Keep it steady

The caster angle has a large effect at high speeds

The camber effect is large at low speeds

汽车基础知识（十五）四轮定位是干啥的

The same

The camber angle is too large

It will also cause the direction to be very heavy

At the same time, there will be some fetal eating

Camber of the front wheels

Also literally

The front wheels are tilted outwards a bit

Other words

View from the front of the car

The two wheels are in the shape of an inverted figure-eight

Its main role is to make the steering wheel lighter

At the same time, it can also reduce the force on the outer bearing of the wheel hub and prevent the tire from slipping outward

But

If the camber angle is too large

It will cause the tires to wear and wear

Today, radial tires and directional assist systems are widely used in automobiles

The lightweight handling type has been well addressed

So the camber is very small

Toe-in of the front wheels

Other words

The front wheels of the car are a bit "inside the figure-eight"

Why is it designed this way?

Think about it, everybody

If the front wheels of the car are tilted

If the vehicle is advancing

Then the front wheels will have a tendency to roll outward

Therefore, let the front wheel "inside the figure-eight".

This tendency to roll outward can be counteracted to a certain extent

Reduces tire wear

Well, the four-wheel alignment is these four angles

Each angle should be adjusted to the appropriate value

Also, if the left and right wheels have different values

Then there will be deviation and tire eating

If the size of the value is not appropriate

It will also have an impact on the stability of the vehicle and the rate of wear of the tires

Here's a typical example:

"Deviation and eating tires, a tape measure did the work of four-wheel alignment"

So

If the vehicle eats the tires severely

Or if you go in the wrong direction

It's time to check the wheel alignment

All right

That's all for today

See you next time

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