From the structural point of view, the double wishbone suspension and the MacPherson suspension have a close blood relationship. What they have in common is that the lower control arm is composed of a V-shaped or A-shaped fork-shaped control arm, hydraulic The shock absorber acts as a support for the entire body. The difference is that the double wishbone suspension has an upper control arm that connects the strut shock absorbers, which effectively enhances the overall reliability and stability of the suspension. In fact, the double wishbone suspension has an interesting name - Doublewishbone. It is said that this interesting name comes from the bones of a kind of turkey that people like to eat in Western Christmas. When people start to eat, they want to make a v-shaped bone on the turkey, and this bone is called bone. (Wishbone). Because there are two "willing bones" in the double wishbone suspension structure, it is named as the double wish bone suspension. The structure of the double wishbone suspension is more complicated, but this gives the wheel better grounding. The double wishbone suspension is inspired by the MacPherson suspension. From a structural point of view, the MacPherson suspension has only one lower control arm and one strut type damper. The simplest structure makes its components usually have a special energy. For example, the strut damper needs to act as a steering kingpin, in addition to bearing the weight of the vehicle itself, but also to deal with the jitter and impact from the road surface. If the vehicle is in motion and the McPherson suspension on one side is compressed by inertia, then the camber change of the wheel will increase, so the more the suspension is compressed, the more difficult it is to control. Therefore, the application range of the MacPherson suspension is mostly small or medium-sized cars. The model level goes up again, and the McPherson suspension with simple structure will be incapable. To improve the "fragile" characteristics of the MacPherson suspension, it is necessary to adjust the composition of the suspension. Since the MacPherson suspension has only two connecting members of the lower control arm and the strut damper, an "L"-shaped structure is formed, and if a control arm can be added to the "L"-shaped end, then The structure of the suspension will be strengthened. So by implanting the control arm on the MacPherson suspension, the double wishbone suspension structure came into being. The change in the physical properties of the double wishbone suspension relative to the MacPherson suspension is obvious: when the suspension of one side is contracted by inertia, the variation of the camber angle of the wheel is relatively small, but the variation of the camber angle of the wheel can also pass. Change the relative length of the upper and lower control arms to improve. As a result, engineers have greater freedom in designing and matching double wishbone suspensions, and are more likely to make the most reasonable adjustments to a particular feature of the car, such as sport or comfort. In fact, at the beginning of the chassis design of the vehicle, the designer began to consider how to arrange a complex suspension structure on the chassis to give the vehicle better handling or smoother comfort. In order to make the wheel fit the ground anytime and anywhere, to achieve the unity of mobility and ride comfort, designers often use the double wishbone suspension structure, increasing the damping of the shock absorber and the hardness of the coil spring is also one of the countermeasures. At this point, the McPherson suspension will increase the camber angle of the wheel due to the thinness of the control arm, and at the same time increase the load on the inside of the tire to increase wear. The upper and lower control arms can share the lateral force, making the body more stable when cornering The double wishbone suspension is composed of two upper and lower unequal-length V-shaped or A-shaped control arms and a strut type hydraulic shock absorber. Usually, the upper control arm is shorter than the lower control arm. One end of the upper control arm is connected to the strut shock absorber, and the other end is connected to the vehicle body; one end of the lower control arm is connected to the wheel, and the other end is connected to the vehicle body. The upper and lower control arms are also connected by a connecting rod, which is also connected to the wheel. Throughout the suspension configuration, the integrity of the upper and lower control arms and the entire suspension is increased by the connection of multiple fulcrums. In the case of a front-wheel drive model, the double-wishbone suspension mounted on the front wheel has a steering mechanism between the upper and lower control arms in addition to the transmission mechanism, which makes the structure better than the rear wheel without the steering mechanism. It is much more complicated. In the steering mechanism, the steering kingpin is determined by the connection position and angle of the steering tray and the upper and lower control arms, and the steering wheel can rotate around the kingpin, and can also jump up and down with the lower control arm. In the double wishbone suspension, the ball joint is usually used to meet the movement requirements of the front wheel: the connection between the upper and lower control arms and the steering king pin must support both the front wheel and the steering wheel. However, due to the length difference between the upper and lower control arms, this also puts a severe test on the design of the double wishbone suspension. If the difference between the lengths of the upper and lower control arms is too small, the wheel will be shaken when the wheel is too large, and the tires will be accelerated. On the outside, if the difference in length between the upper and lower arms is too large, the camber angle will be too large when the wheel is turned, and the wear on the inner side of the tire will be accelerated. Therefore, it is a good idea to reduce the variation of the track and to control the change of the camber angle by increasing the length of the upper and lower control arms. It is worth mentioning that the upper and lower control arms of the double wishbone suspension can counteract the lateral force, which makes the strut damper no longer bear the lateral force, but only the up and down vibration of the wheel, so on the curve Has good directional stability. The Mazda 6, which is known as the "king of the corner", is a double wishbone suspension. Therefore, the Mazda 6 has a small roll when driving in a corner, and the overall feel of the body is kept very good. The combined performance of the double wishbone suspension takes up more space than other forms of independent suspension Since the traditional double wishbone suspension adopts a single guiding structure, that is, the upper and lower control arms are connected with the strut damper to realize the control of the up and down movement direction of the wheel, the steering rod and the main pin are connected to complete the control of the left and right direction of the wheel. From this point of view, shock absorption and steering are controlled by two independent mechanisms, but both mechanisms are only single-guided. With the continuous optimization and improvement of the suspension structure, the current double wishbone suspension has derived a two-way control structure that can simultaneously be responsible for wheel steering and up and down jitter. On the Peugeot 407, the front overhang uses a two-way controlled modified double wishbone suspension called the "independent journal double fork front wheel system". The improved suspension knuckle and knuckle bracket replaces the condition of restraining the wheel with only the upper and lower control arms, which are accomplished by a knuckle hinge mounted between the knuckle brackets. In the front suspension with steering mechanism, the steering knuckle bracket connects the knuckle ball hinge, the stabilizer bar, the hydraulic shock absorber, and the upper and lower arms. The beating and steering of the wheel are respectively responsible for these two new components. The new structure allows each part to withstand much less force than the conventional double wishbone, and the reliability is improved a lot. In addition, the dynamic performance is greatly improved. The new double wishbone suspension achieves a smaller kingpin inclination and camber angle, and the steering wheel automatically corrects the effect more obviously. Despite the many advantages of the double wishbone independent suspension - excellent lateral support, precise wheel direction control, etc., due to the use of the upper and lower control arm structure, the over-stable characteristics make the wheel's response speed better than other forms of suspension. Slowly, the structure of the upper and lower control arms also results in an increase in the lateral mounting space of such a suspension. Therefore, the double wishbone suspension often appears in large luxury cars, full-size SUVs, pickups and even super sports cars, such as the familiar Cadillac Sail, Citroen C6, Audi Q7, Volkswagen Touareg, and even domestically produced ZTE Tigers. One exception is the use of a double wishbone structure in the front overhang. The sports car with attention to handling performance such as Lamborghini Gallardo and Maserati 3000GT adopts double wishbone suspension in front and rear suspension, which is enough to illustrate the wide range of applications of the double wishbone. The important thing is that it can provide a good lateral direction for the body. support. Xi'an Jmlai Bio-Tech Co., Ltd. , https://www.jmlaisarms.com
Double wishbone independent suspension for performance complex suspension system