What is the knowledge of four wheel alignment, what is the main content of four wheel alignment?

When the vehicle leaves the factory, the positioning angle of its suspension system (there are 7 basic positioning angles) are pre-set according to the design requirements. Together, these positioning angles are used to ensure the comfort and safety of the vehicle.

However, after the vehicle has been sold and driven for a period of time, these positioning angles can change due to traffic accidents, violent bumps caused by uneven road potholes (especially when driving at high speeds, sudden encounters with uneven road surfaces), wear and tear of chassis parts, replacement of chassis parts, replacement of tires, etc. Once the positioning angle changes due to any of the reasons, it may cause uncomfortable symptoms such as abnormal tire wear, vehicle mistracking, reduced safety, increased fuel consumption, accelerated wear of parts, sinking steering wheel, and vehicle fluttering. There are some symptoms that make the vehicle very dangerous at high speeds.

The purpose of the four-wheel alignment maintenance service is to diagnose the above-mentioned discomfort of the vehicle through the positioning angle measurement and give it.

Generally, a new car should be driven for 3 months after the four-wheel alignment, and after every 10,000 kilometers driven, the tires or shock absorbers should be replaced, and the four-wheel alignment should be done in time after a collision.

Correct wheel alignment can ensure flexible steering, comfortable seating, maintain straight driving, prolong tire life, and reduce vibration caused by road surface.

Alignment of the front wheels that is not within the standard range can lead to: abnormal tire wear, unstable direction, and shivering.

The main factors affecting the four-wheel alignment are: driving at high speed on uneven roads; The front wheels are impacted by external forces, such as passing over pits, going up sidewalk steps, etc.; often kill in the direction of the same place; The tire pressure is out of the standard range.

To carry out four-wheel alignment, you need to use four-wheel aligner, which is mainly composed of two parts: one part is computer software and hardware, the computer is our common PC, and the key to this part is the vehicle specification database; The other part is the sensing head, which is mainly composed of two sensing elements: 1. an angle meter, 2. a potentiometer (pull wire) or an infrared imaging sensor (infrared type).

Potentiometers or infrared imaging sensors are used to measure beam angles, retraction angles, propulsion angles, and track angles, and goniometers are used to measure camber angles. When taking a steering wheel measurement, the goniometer is combined with a potentiometer or infrared imaging sensor, and the results are calculated by a computer, which can measure the caster angle of the kingpin, the caster angle of the kingpin and the steering angle. Therefore, the beam angle, the retraction angle, the propulsion angle, the pitch difference and the camber angle can be measured directly without hitting the direction, and the caster angle of the kingpin, the caster angle of the kingpin and the steering angle are the angles that must be measured indirectly by hitting the steering wheel.

Correct operation when driving: When passing through obstacles, try to go as slowly and detour as possible; Prevent tires from coming into contact with grease and fuel; The front tire pattern must be consistent, which can ensure the best driving performance and prevent the occurrence of drifting, insufficient anti-force, noise and eccentric wear; After renewing and repairing the tires, tire balancing must be carried out.

1. The function of automobile four-wheel alignment is:

It is conducive to the car to maintain a stable straight line and light steering, and reduce the wear and tear of tires and steering parts during driving.

2. Under what circumstances do you need to do four-wheel alignment?

When driving the vehicle, you feel that the direction of the steering is heavy, shivering, misaligned, not homecoming, or you find that the tires are unilaterally worn, corrugated worn, block worn, eccentric wear and other abnormal wear and tear, as well as when driving, the car feels floating, trembling, swaying and other phenomena, you should do four-wheel alignment.

1) Tire pressure and tire tread wear: Uneven tire wear indicates a failure in certain aspects such as tires, steering or suspension. (There are many reasons why tires wear out irregularly and wear out too quickly.)

The most common reasons are improper inflation pressure, not regularly changing tires, improper driving habits, or incorrect alignment of the original four wheels. )

2) Wheel oscillation: Oscillation is a condition that causes unstable rotation of tires due to various reasons, and the oscillation of wheels and tires refers to irregular up-and-down or side-to-side movements. Left-right motion refers to the lateral oscillation of the wheel or tire, and up-down motion refers to the radial oscillation of the wheel or tire.

Vibration faults related to the oscillation can only be eliminated by looking for the ** of the oscillation.

3) Wheel deviation: Deviation refers to the deviation of the vehicle driving direction when the vehicle is driving on a straight road, and the steering wheel is not affected by any external force. Mistracking is usually caused by:

Tire structure (radial transverse force).

Improper fit or uneven wear of the tires.

Improper alignment of the front or rear wheels.

The steering valve is off-center.

Uneven brake adjustment or brake lag.

The order of four-wheel alignment: successively the wheel and then the front wheel; Camber first to kingpin and then toe-in. Check the tire model, air pressure and wear before adjustment; the condition of the suspension components; Whether the vehicle height is the same. It is best to change the tire position and try the car before positioning, and check whether there is a toot.

Is the steering wheel biased, or does it refer to the vehicle grabbing the steering wheel or eating tires, running off, these are all required four-wheel alignment, ** in about three hundred.

The installation between the steering wheel, the steering knuckle and the front axle of the car has a certain relative position, and this installation with a certain relative position is called steering wheel alignment, also known as front wheel alignment. The front wheel alignment includes four contents: kingpin camber (angle), kingpin camber (angle), front wheel camber (angle) and front wheel toe.

Tire benefits: Since it is called four-wheel alignment, it must be a very big benefit to tires in the first place. After the four-wheel alignment, the tires can maintain the optimal angle between the tire and the car body, which improves the grip and ensures comfort.

Improved handling: Keeping the tires in normal condition is of course very good for driving safety. After the four-wheel alignment adjustment, the driving handling can be guaranteed accordingly.

Especially in case of emergency, the tires have enough grip to follow the driver's trajectory as much as possible.

Fuel saving: It is obvious that fuel consumption decreases as the rolling coefficient of friction decreases of the tire. After the adjustment of the four-wheel alignment, the vehicle can follow the correct trajectory, which reduces the wind resistance to a certain extent, and of course, the fuel consumption will also be reduced.

Safety guarantee: If the tires are good, the safety will be greatly improved. In fact, after the four-wheel alignment adjustment, the maintenance technician will also check the condition of the suspension system and other components of the car, and this inspection can determine whether the tires have an adverse effect on the chassis system.

If an abnormality is found, not only the tires are optimized, but the chassis is also trimmed accordingly, so that the wear degree of the corresponding components can be judged through the tires, and the potential safety hazards can be found as soon as possible and completely eliminated.

The four-wheel alignment mainly includes the front wheel alignment and the rear wheel alignment, and the front wheel alignment includes four contents: kingpin tilt, kingpin tilt, front wheel camber and front wheel toe-in; Rear wheel alignment includes wheel camber and rear-wheel toe-by-wheel. Four-wheel alignment is based on the vehicle's four-wheel parameters, which are adjusted to ensure good driving performance and certain reliability. The role of wheel alignment:

Increase driving safety; Reduced tire wear; Keep the steering wheel straight when driving straight, and maintain straight driving; The steering wheel automatically straightens after steering; Increases the sense of driving control; Reduced combustion consumption; Reduces wear and tear on suspension components. The vehicle must have good straight-ahead performance for stable driving, cornering performance for driving around curves, recovery ability to return to straight-ahead state, and ability to slow down vibrations transmitted to the suspension when the tires are hit. Therefore, for various suspensions for different purposes, the wheels should be mounted at a specific angle to the ground, which is called wheel alignment.

Wheel alignment (four-wheel alignment) includes state huai front and rear wheel alignment: front wheel alignment includes kingpin camber, kingpin camber, front wheel camber and sail huai you front wheel toe four contents. Rear wheel alignment includes wheel camber and rear-wheel toe-in.

The four-wheel alignment function makes the car keep a stable straight line, will not deviate, and ensure driving safety

1.The four-wheel alignment function keeps the best angle between the tire and the car body, does not eat the tire, reduces the wear between the tire and the steering parts during the driving process, and prolongs the service life of the tire.

2.Four-wheel alignment refers to the relative position and angle that should be attached between the four wheels, steering mechanism, and front and rear axles of the adjustment car, which is specified by the manufacturer.

3.If the car is driven in poor road conditions for a long time or when the tires and chassis are bumped, this relative position will be inaccurate, and the car will be affected, so it is necessary to carry out four-wheel alignment.

The four-wheel alignment is based on the four-wheel parameters of the vehicle, and is adjusted to ensure a good driving of the vehicle.

Function. The front wheel alignment includes four contents: kingpin camber (angle), kingpin camber (angle), front wheel camber (angle) and front wheel toe. Rear-wheel alignment includes wheel camber and rear-by-wheel toe-in.

In this way, the front type of sun wheel alignment and rear wheel alignment are collectively called wheel alignment, which is often called four-wheel alignment. The function of wheel alignment is to keep the car stable and straight, and to steer lightly, and to reduce the wear and tear of the tires and steering parts of the car while driving.

Kingpin caster.

When viewed from the side, the steering kingpin (the center of rotation of the wheel when turning) is tilted backwards, which is called the kingpin caster. After setting the caster angle of the kingpin, the distance between the grounding point of the kingpin centerline and the ground projection point in the center of the wheel (called the kingpin pitch distance, which is the same as the principle of the front wheel fork beam of the bicycle tilting backwards), so that the grounding point of the wheel is located at the rear end of the extension line of the kingpin in the transfer lease, and the wheel is pulled back by the rolling resistance in the running, so that the direction of the wheel is naturally towards the direction of travel. Setting a large caster angle of the kingpin improves straight-line driving performance and increases the kingpin pitch distance.

Too much kingpin trim can weigh the steering wheel and exacerbate the front and rear bumps of the wheels due to road interference.

Kingpin camber.

When looking at the tires from the front and rear of the car, the kingpin shaft is tilted towards the inside of the body, and this angle is called the kingpin camber. When the wheel rotates with the kingpin as the center, the lowest point of the wheel will fall below the road surface, but in fact the lower edge of the wheel cannot fall below the road surface, but the steering wheel together with the entire front of the car will be lifted up to a corresponding height, so that the gravity of the car itself has the effect of making the steering wheel return to the original middle position, so that the steering wheel is easy to reset.

The front wheels are cambered. When looking at the wheels from the front and rear, the tires are not mounted vertically, but are slightly tilted and open in a figure-eight shape, which is called negative camber, and when opened in the opposite direction, it is called positive camber.

Toe-in of the front wheels. Four-wheel alignment toe-in value.

The toe is inward, and the so-called "inner figure-eight foot" means that the left and right front wheels are facing inwards respectively. The purpose of adopting this structure is to correct the outward rotation of the wheels caused by the camber angle of the front wheels mentioned above. As mentioned earlier, steering wheel operation is made easy thanks to camber.

On the other hand, due to the tilt of the wheels, the left and right front wheels rotate outwards respectively, and in order to correct this problem, if the left and right wheels have an inward angle, the plus or minus is zero, and the left and right wheels can keep traveling in a straight line, reducing tire wear.

The four-wheel alignment of the car is: 1. The installation between the steering wheel, the steering knuckle and the front axle has a certain relative position called steering wheel alignment; 2. The front wheel alignment includes four contents: kingpin camber, kingpin camber, front wheel camber and front wheel toe; 3. Rear wheel alignment includes wheel camber angle and toe-in of each rear wheel, and the front wheel alignment and rear wheel alignment are collectively referred to as four-wheel alignment. Steps for wheel alignment:

1. Drive the vehicle on the positioning four-post lifting frame, check the tire gas base pressure and vehicle height; 2. After the fiber and four wheels are suspended, carefully check whether the tires are irregularly worn and deformed, and if the wear reaches the standard, the steering ball joint can be measured whether there is looseness and whether the length of the left and right tie rods is consistent; 3. Check whether the upper and lower suspensions, stabilizer bars, 40,000 frames and girders are deformed and loosened; 4. Check whether the rear axle, cross power lever and rear tie rod are deformed, and whether the rubber sleeve is loose; 5. Put down the vehicle after there is no abnormality, shake the vehicle several times to prove that the suspension system is in a normal state, and open the four-wheel alignment fixing pin.

The main do rolling pins, backward tilting, outer early Hu key tilting, toe.

The four-wheel alignment is based on the four-wheel parameters of the vehicle, and is adjusted to ensure that the vehicle has good driving performance and has a certain degree of reliable land dexterity.

Caster tilt kingpin tilt Caster camber of the front wheel Toe of the front wheel.

The kingpin is tilted back. The four-wheel alignment is based on the number of four-wheel ginseng mu of the vehicle, and the communication service is adjusted to ensure that the vehicle has good driving performance and has a certain degree of reliability.

1. The so-called four-wheel positioning refers to the average advancement direction of the Sakura's wheel after dismantling as the positioning hall song jujube benchmark to measure and correct the positioning angle related to the four wheels; The chassis parts and tires can be maintained when the vehicle is driving.

Four-wheel alignment plays a very important role in the normal driving of the car, the majority of car friends must not be ignored, after the car has been driving for a period of time, due to various reasons, there will be abnormal tire wear, parts wear and tear accelerated, steering wheel sinking, vehicle deviation, fuel consumption increased and other phenomena, and these phenomena are the reasons for the decline in vehicle performance, to eliminate these phenomena, to ensure the stability of the vehicle, the most effective way is to do four-wheel alignment, it can not only ensure the normal driving of the car, but also extend the service life of the tires, At the same time, fuel consumption is saved.

Four-wheel alignment refers to the vehicle factory, the positioning angle of its suspension system, these positioning angles are pre-set according to the design requirements, to ensure the safety of vehicle driving, the above angle refers to the angle between the suspension system and the moving parts, maintaining the correct four-wheel alignment angle can ensure the vehicle's straightness, handling and steering system recovery, avoid bearing damage and loss of accuracy due to improper stress, but also ensure that the tire and the ground are tightly engaged, reduce improper tire wear, and ensure the stability of the car when turning.

The purpose of four-wheel alignment is to diagnose the above-mentioned discomfort symptoms of the vehicle by measuring the positioning angle and give **, it is divided into front wheel alignment and rear wheel alignment, the front wheel alignment includes the caster angle of the kingpin, the caster angle of the kingpin, the camber angle of the front wheel and the toe of the front wheel four contents of the round draft, the rear wheel positioning includes the camber angle of the wheel and the toe of the rear wheel. Under normal circumstances, after driving a new car for 3 months, it should do four-wheel alignment, and then every 10,000 kilometers after driving, the tire should be rotated If a collision occurs, four-wheel alignment should be done in time.

The above talked about the importance of car four-wheel alignment, let's talk about the problems that should be paid attention to when doing four-wheel alignment, when choosing a car maintenance shop in Orange State, you must choose a professional car maintenance shop, because experience, technical and technical technicians with advanced four-wheel alignment, in order to provide the best service for your car, with the evolution of the suspension system from simple to complex, its structure is becoming more and more complex, and the corresponding requirements for four-wheel alignment angle are getting higher and higher, therefore, there is a certain model designated four-wheel aligner, The four-wheel aligner is not an instrument used to adjust and change the positioning angle, it is only used to measure the positioning angle, and then, the technician uses this as a reference to compare with the angle set by the original factory, and adjusts and changes the positioning angle to restore the original design angle.

In addition, the main factors affecting four-wheel alignment are: (1) driving at high speed on uneven road surface; (2) The front wheel is impacted by external force, and the sidewalk steps are on; (3) often kill in the same direction; (4) The tire pressure is outside the standard range. Therefore, the majority of riders should pay attention to the following points when maintaining your car:

1) When passing through obstacles, try to slow down and detour; (2) The front tire pattern must be consistent, which can ensure the best driving performance and prevent the occurrence of insufficient adhesion, noise, side slip, eccentric wear and other phenomena; (3) After updating or repairing the tire, the tire dynamic balance test must be carried out.