a double wishbone independent suspension
double-wishbone suspension, also known as double A-arm type independent suspension, double-wishbone suspension fork has two upper and lower arms, while the transverse forces absorbed by the two fork arms , strut carries only the weight of the vehicle body, so a large lateral stiffness. A fork-shaped upper and lower arms can be precisely positioned double-wishbone front suspension of the various parameters, when the nose wheel steering, two upper and lower wishbones can absorb suffered tire lateral force, combined with the two fork arms lateral rigidity is large, a smaller turning roll. Double-wishbone suspension usually vertical unequal length wishbones (the short length), so that the outer wheels can be automatically changed when the vertical movement and the inclination angle is reduced to reduce the tire wear gauge changing, adaptively, and the road, the tire ground contact area, stick to good. Double-wishbone suspension excellent mobility, Ferrari, Maserati supercar other use.
the history of
double-wishbone independent suspension has an interesting name mdash; mdash; double wish bone suspension (Double wish bone). It is said that this interesting name comes from the Western Christmas people like to eat a turkey bone, when people began to eat the body of the turkey when a similar V-shaped bones make a wish, and that wish bone is called bone (Wish bone). Because there are two double-wishbone suspension structure in ldquo arm; rdquo ;, wish bone so named double wish bone type suspension.
born double-wishbone suspension and McPherson suspension kinship closely, as they have in common: the control arm by a V-shaped or A-shaped control arm fork configuration, acts as a hydraulic damper strut support the whole body. The differences in that double-wishbone suspension on a plurality of connecting strut damper control arm, so that effectively enhances the overall reliability and stability of the suspension. From a structural point of view, only a McPherson suspension lower control arm and a strut type shock absorber, the simplified structure makes most of the components are usually multi-skill. For example, need to act as a shock absorber strut turnThe kingpin, in addition to bear the weight of the vehicle itself, but also to deal with jitter and the impact from the road surface. If the vehicle is in motion, McPherson strut compression side by inertia, the outer wheel angle change increases, so more compressed badly suspension, this deformation the more difficult to control. So McPherson strut range of applications, mostly small or mid-size sedan, Model Level Beyond it, a simple structure McPherson suspension will be somewhat insufficient.
McPherson suspension to improve ldquo; fragile rdquo; characteristics, it is necessary to adjust the composition of the suspension structure. Since only the Macpherson suspension lower control arm and shock absorber strut connecting two members, so that it forms a ldquo; Lrdquo; shaped configuration, if the ldquo; Lrdquo; add a top-shaped control arm , then the structure of the suspension will be strengthened. Thus by the implantation of the McPherson suspension control arm, double-wishbone suspension structure have come into being. Double wishbone suspension relative McPherson strut on the physical characteristics of the change in apparent: When one side of the suspension due to contraction of inertia, the outer wheel angle change is relatively small, but the change in the size of the camber can also varying the relative length of the upper and lower control arms to improve. Therefore, engineers more freedom in the design and matching double-wishbone suspension, better car for a certain characteristic, such as sport or comfort to make the most reasonable adjustment.
In fact, at the beginning of the design of the vehicle chassis, designers began to consider how to lay out the complex structure of the suspension to the chassis, giving the vehicle a better or more stable handling comfort. In order to be able to fit the wheels ground at any time, to achieve the unity of sportiness and ride comfort, the designer often uses double wishbone suspension structure, increase the hardness and shock absorber damping coil spring is one of the measures to deal with. In this regard, McPherson suspension thin because the increased camber control arms, while the inner tire load increases and increased wear. Since the conventional double-wishbone suspension single guide structure, i.e., the upper and lower control arms and a shock absorber strut is connected to the wheel to achieve control of the vertical movement direction, and the steering rod coupled to the kingpin of the wheel complete control of the right and left direction. In view of this, damping and steering are controlled by two independent means, but comprising only two single-oriented mechanism. With the optimized suspension structure improvements, currently has double wishbone suspensionIt can be derived from the steering wheel and is also responsible for controlling the structure of the bidirectional vertical jitter. On the Peugeot 407, he called the front suspension uses ldquo; independent double wishbone front journal system rdquo; bidirectional control improved double wishbone suspension. With improved suspension knuckle and the knuckle bracket to replace only the constraint condition of the upper and lower control arms of the wheel, the wheel is mounted between the steering knuckle by a knuckle bracket hinge is completed. Sling before the steering mechanism, the steering bracket is connected to the knuckle section spherical hinge, the stabilizer bar, the hydraulic damper and the upper and lower arms. And a steering wheel runout are undertaken by the two new members, new structure allows each of the force receiving part than the conventional double wishbone much smaller, many improved reliability. Further also greatly improved dynamic performance, new double wishbone suspension obtained in smaller kingpin inclination and camber, while the steering wheel is more effective self-aligning.
configured Principle
by a double-wishbone suspension two unequal vertical V-shaped or A-shaped control arm and the strut-type hydraulic damper configured, generally the control arm is shorter than the control arm. One end of the control arm on the shock absorber strut is connected to the other end is connected to a vehicle body; end of the lower control arm is connected to the wheels, and the other end connected to the vehicle body. Further the upper and lower control arms are connected by a connecting rod, which tie rods also further connected with the wheel. Throughout the suspension structure by connecting a plurality of the upper and lower pivot of the control arm, and improve the integrity of the entire suspension.
If the vehicle is front wheel drive, then the double wishbone suspension assembly to the front wheel in between upper and lower control arms in addition equipped with a transmission mechanism, there are a steering mechanism, which makes its structure than does with rear wheel steering mechanism is much more complex. In the steering mechanism, the kingpin angle is determined by the connection position and the upper and lower control arms and steering of the tray, the steering wheel is rotatable about the main pin, while the arm can be controlled at beating with. In the double-wishbone suspension connected commonly employed to meet the ball movement needs front wheel: the upper and lower control arm kingpin support is connected to both the front portion and also to achieve control of the steering wheel vertical jitter. However, due to the difference in length of the upper and lower control arms issues, which also double-wishbone suspension design poses a severe test mdash; mdash; if the length of the upper and lower control arms of difference is too small, too large will cause the track around the wheel shake, accelerate the outside of the tire wear; conversely, if the upper and lower arm length difference is too large, the steering wheel will result in an outer tilting whenAngle is too large, the inside of the tire to wear faster. Thus, it is possible to reduce variation in the control track outside the tilt angle change and by increasing the length of the upper and lower control arms.
Further, the upper and lower control arms of a double wishbone suspension counteract the lateral force can play effect, which makes it no longer withstand the shock absorber strut lateral force, but only respond to shake up and down the wheels, so It has good directional stability on a bend. Known ldquo; Wang the curve rdquo; reputation is Mazda suspension uses double wishbone front suspension 6. Therefore, roll in corners Mazda 6 traveling in a smaller, the overall sense of the body is kept very well.
Technical features
advantages
lateral rigidity, excellent anti-roll performance, grip performance, road feel clear.
First, the precise positioning of the control parameters, so that the wheels can be a good close to the ground, a strong transverse rigidity and provides good lateral support for the handling of the vehicle, this structural superiority is obvious, it is not only Ferrari, Lamborghini and Maserati sports car of choice for these, even today’s F1 car used in the suspension structure can still see the shadow of the double wishbone. And two triangular configuration of the rocker arm also has excellent lateral stiffness and torsional strength, and therefore often use double-wishbone suspension structure on hardcore pickup or SUV, and the structure of the double-wishbone front bridge is integrally hardcore off-road SUV’s classic structure. Like Grand Cherokee, Toyota and VW Touareg Prado, front suspension are inserted by double arm suspension structure.
drawbacks
high manufacturing costs, complex suspension positioning parameter setting.
relative to the McPherson suspension, its structure is more complicated, larger space, high cost, and therefore not suitable for small car front suspension, in addition, requires accurate location parameters determined and calculated calibration for the manufacturer’s technical strength is relatively high.