Car suspension - a device that provides the elastic vehicle traction carrier system and adjusts the position of the body in motion and reduces the load on the wheels. Modern automotive offers different types of car suspension:
- air,
- spring,
- spring,
- torsion, etc.
Guiding suspension. Collection of devices that connect the wheels and the car body, forms a suspension. The main purpose of the suspension is to transform the impact on the car at the side of the road in the permitted variation of the body and wheels. These interactions must be such that the vehicle is not only quickly gathered speed (accelerated), but could not slow down even faster (up to a full stop). Besides, the car while driving should be easily controlled and be sustained. To perform these tasks, and serves as a suspension design which determines the basic performance of the car, including safety.
When the vehicle wheels are moved relative to the body and the road in the vertical and horizontal directions, and the angle (rotation about an axis relative to the body and the inclination of the road , turn around the axis of rotation - the kingpin axis). To fulfill the requirements related to the performance of the car, we have to severely restrict the movement of the wheels. In transverse (sideways) movement of the wheels in the horizontal directions track changes and the longitudinal - base vehicle. The presence of such movements leads to increased resistance to movement, tire wear, poor stability and controllability. Vertical movement of the wheels relative to the body in cars can exceed 20 cm rotation angles of the wheels are 30 ... 45 °.
In order to successfully car accelerated and braked well "held" the way, you must have a secure grip surface with its wheels. Does the suspension on the clutch? Certainly. Adhesion is dependent not only on the characteristics of the tire tread and road quality, but also on the load which is transmitted to the wheels. Changing the vertical load on the wheel spring deflection and determined effort by the shock absorbers. By reducing the vertical load decreases since the wheels grip the road surface.
Suspension of the car includes the following main components: guidance devices (levers, racks, traction, stretching), the elastic elements (leaf springs, coil springs, air springs, etc.), extinguishing devices (hydraulic shock absorbers), and finally, regulation and control devices (height adjusters and roll, computers, etc.).
Guiding suspension affect the character of the movement of the body and the wheels when the vehicle vibrations. Would, for example, lifting wheels accompanied its inclination, lateral or longitudinal movement depends on what scheme made vanes. Guiding devices are used to transmit traction and braking forces and lateral forces generated by rotation , the slope movement of the wheels to the body.
By type vanes all pendants are divided into dependent and independent. In dependent suspension right and left wheels are connected rigid beam - bridge. Therefore, when driving over uneven one of the wheels both wheels are tilted in the transverse plane at the same angle. In independent suspension movement of one wheel is not strictly related to the displacements of the other. Slopes and moving right and left wheels are substantially different.
Elastic device ( elastic members ) are used to reduce the loads acting between the wheel and the vehicle body. When driving over road irregularities occur deformation of elastic elements. After the drive irregularities elastic elements cause fluctuations body and wheels. The main characteristic is the rigidity of the elastic elements, ie the ratio of vertical load to deflection (or sediment spring). Elastic wheel suspension elements are distinguished not only by the structure, but also depending on the material from which they are made. When using the elastic properties of metal (or bending resistance to torsion), then there are elastic metal elements. Given the elastic properties of rubber and plastic , widely used rubber and plastic springs. Recently become widespread bellows, which uses the elastic properties of air or other gases.
Extinguishing suspension device (hydraulic shock absorbers) are designed for vibration damping body and wheels. During the suspension of the oscillation energy is redistributed between the car body and wheels. Dampers absorb this energy and convert it into heat. The more energy absorbs shock, the faster will be damped oscillations of the body and the wheels, lower the body sway. Ride on soft -suspension springs almost impossible.
Significantly reduce the inclination and lateral wheel movement is possible, using double wishbones scheme . A short upper and long lower arms can reduce the angular and lateral motion of the wheels. Effect of inclination (angle) can be reduced by the collapse (slope) of the wheels in a vertical plane and descent (the difference between the lateral surfaces of the tire in front and rear) wheels. Lateral motion of wheels can be compensated pliability tires.
Double wishbones has several advantages in the arrangement of the basic elements: a shock absorber mounted inside the spring; spring and shock absorber based on the lower arm, which reduces the dimensions of height; wishbones reliably transmit pushing and braking forces from the wheel to the body. Double wishbones guide devices have proliferated in the front independent suspension cars.
More than the angular and transverse displacements in guiding devices in spring struts telescopic front wheel drive vehicles, where instead of the two levers in the transverse plane is set one lower wishbone with stretch marks. This suspension was called swinging candle, or, as it is called by the name of the inventor, MacPherson suspension. When only the lower arm and the upper support suspension has minor changes track and tilt wheel, which reduces tire wear and increases the stability of the vehicle. The disadvantages of this scheme has a high position of the upper support, which should be placed in front of the body, as well as heavy loads, resulting in the attachment points of the top support to the body.
Using the trailing arms in the guide devices avoids the tilt wheel during vertical movements. However, long trailing arms are experiencing a lot of stress under the influence of lateral forces (when turning the Congress on the sidelines, impacts pothole). With this construction, the guide device in independent suspensions difficult to drive to the wheel with the help of driveline, to reduce body roll side, we have to install an additional elastic element - anti-roll bar. Vanes with trailing arm rear suspension used on front wheel drive vehicles.
Elastic suspension elements. Consider the design of elastic elements (springs) suspension. The oldest elastic element is leaf spring. Normal leaf spring is a package (trapezoid) strapped flat steel strips. Longest root list has eyelets at the ends by a spring which is attached to the body. Most often longitudinal leaf springs mounted on the rear suspensions of cars. The more sheets in the package, the greater the load can absorb spring. Increased length makes it possible to increase the spring deflection and therefore move the wheels, i.e. make long-travel suspension and soft. The main feature of the leaf springs is that they can not only fulfill the role of an elastic member, but the guide apparatus. Transmitted through the leaf spring all stresses of rolling wheels. Spring transmit pushing force during acceleration and braking. During the movement of the slope, turning the vehicle and under the influence of the other side silressory subjected to torsion. The greatest burden falls on indigenous sheets spring. The durability of the leaf springs at higher load is significantly reduced. Another feature is the..