Front wheel suspension
The central part of the front suspension is the so-called suspension strut, to which the wheel is directly attached and it serves to spring and absorb shocks and shocks. elastically "suspended" the bearing connects the suspension strut in its upper part to the body. At the bottom of the rack is connected to the front axle beam pivotally, through the so-called transverse suspension arm.
Attached to both wishbones is also a round, several times bent, spring steel rod - the so-called anti-roll bar. It works as follows: when the inner wheel is spring-loaded during a turn, the stabilizer twists. With the help of the spring force thus generated, the suspension of the outer (in relation to turning) wheels and. thus its spring is strengthened to a certain extent. The result: the car leans much less when cornering. If the car springs - for example, when braking, evenly in front, then the stabilizer does not work. Due to its location, the anti-roll bar also absorbs shocks that act on the suspension from the front.
1 Anti-roll bar
2 Wishbone
3 Drive shaft
4 Suspension strut steering knuckle arm
5 Suspension strut
6 Rack and pinion steering
7 Steering shaft
8 Brake disc
Breaking shoulder
There is another design feature of the front suspension: direction-stabilizing steering kinematics. She. for example, it provides safety when braking on different road surfaces between the left and right front wheels.
This is achieved by the so-called running-in shoulder, which is negative for Audi vehicles. You can think of it like this: connect the upper and lower support points of the shock absorber with an imaginary line and see where it is (continuing down) touches the ground.
For Audi models, the touch point is outside the wheel center, so we are talking about a negative running-in shoulder here. If this point were closer to the middle of the car, then the break-in shoulder would be positive.
When cornering, the front wheel moves along the arc of the point (A). There touches the road the continuation of an imaginary line (shown in the center and right figures). Dot (V) indicates the center of the tire contact surface. Radius (a-c) arc and is the running shoulder. This running-in shoulder depends on the position of the steering axis: if the steering axis touches the road inside the vehicle wheels (wheel center distance), then the break-in shoulder will be positive. It is negative when the steering axis touches the road outside the wheels.
The front wheels for safe driving conditions must be installed in the longitudinal and lateral directions at certain angles. Some of the concepts are explained below:
Convergence
Unlike many other cars, the front wheels at rest are exactly parallel to each other, i.e. convergence is neutral. Under the force of friction between the wheel and the road, the left wheel is pressed to the left, and the right wheel is pressed to the right. This is compensated by the force of the front drive, which tries to press the wheels together again. When turning the car and driving along a curve, the neutral convergence turns into a negative convergence or divergence due to the trapezoidal arrangement of the steering rods. The inner wheel rotates more than the outer wheel relative to the turn. This is also necessary because when turning, the inner wheels must describe a smaller circle than the outer ones. This automatically provides cornering support and additional turning force.
Collapse
This is the name of a small external inclination of the front wheels - at the top in the wheel arch between the wheels, the Audi has a smaller distance than at the bottom near the road surface. This is called negative camber.
Rear axle
1 Longitudinal growl ("crank")
2 V-beam bridge
3 Right suspension strut
4 Panhard rod
5 Left suspension strut
6 Wheel hub
Kingpin transverse tilt (axis of rotation)
This concept refers to the collapse. This is the slight inclination of the pivot axis around which the entire assembly rotates when rotated. Between these two axes at the top there is a smaller distance than at the bottom. Camber and lateral inclination of the kingpin prevents vibration of the wheels.
Longitudinal inclination of the kingpin (axis of rotation)
This refers to the inclined position of the axis of rotation in the longitudinal direction (along the car). This helps to stabilize the straight line and prevents vibration of the wheels. In addition, it helps to return the steering to the straight-ahead position after a turn.
Steering
The rotation of the steering wheel is transmitted to the steering mechanism, which is located behind the engine in front of the dividing wall to the body, converts into lateral movements so that the front wheels can be turned to the side. The Audi car has rack and pinion steering. The gear at the end of the steering column meshes with the rack and moves it depending on whether the steering wheel is turned to the right or left. These movements are transmitted to two steering rods, mounted on the ends of the gear rack and then to the pivot pins of the wheels (knuckles) and from them to the wheels.
To reduce the transmission of road roughness to the steering wheel, on cars without steering, a vibration damper is mounted on the steering mechanism.
Power Steering
In the presence of power steering, the gear rack of the steering mechanism also serves as a piston. Under the action of the hydraulic fluid pumped by the pump, it will move to the right or left. In which direction the liquid is pumped is determined by the rotation of the steering wheel. This movement is transmitted to a valve system that controls the direction and amount of fluid flow.
The pressure in the hydraulic system is created by the impeller pump of the central hydraulic device. which is driven via a V-belt.
Suspensions of both wheels are connected by means of a steel carrier open at the bottom. She. in turn, is held by a crank, which is hinged forward to the body. Properties similar to those of a stabilizer. the bridge has due to the fact that the cross beam (bearing) not rigid, but to a certain extent bent.
The control of the rear axle during curvilinear motion on Audi models is taken over by the so-called Panhard rod. It lies parallel to the transverse beam of the bridge and is pivotally connected both to it and to the body. Thus. it can take the transverse force of the bridge, but also, due to its position, can follow all changes in traffic conditions.
For springing and damping vibrations here, as well as on the front axle, shock absorber struts located at the ends of the axle are used.
Visitor comments