【導(dǎo)讀】懸架是汽車上的重要總成之一，懸架的作用是彈性地連接車橋和車架，減緩行駛中車輛受到由路面不平引起的沖擊力，保證乘坐舒適和貨物完好，迅速衰減由于彈性系統(tǒng)引起的振動，使車輪按一定軌跡相對車身運(yùn)動。懸架決定著汽車的穩(wěn)定性、舒適性和安全性，所以研究懸架成為研究汽車中的重要一個環(huán)節(jié)，ADAMS軟件為研究汽車懸架運(yùn)動學(xué)分析提供了幫助。然后通過ADAMS軟件的后處理功能優(yōu)化前懸架模型，最后得出使輪胎接地點(diǎn)的側(cè)向滑移量變化最小的一組數(shù)據(jù)。從而達(dá)到優(yōu)化的效果。傳統(tǒng)的鋼板彈簧式懸架已難以滿足汽車行駛舒適性和操縱穩(wěn)定性等方面提出的要求，本次畢業(yè)設(shè)計針對雙橫臂式前獨(dú)立懸架進(jìn)行分析，就是通過建立懸架模型，初選懸架各參數(shù)，創(chuàng)建設(shè)計變量，最后利用ADAMS軟件對懸架進(jìn)行優(yōu)化，優(yōu)化出一組使得車輪接地點(diǎn)的側(cè)向滑移量最小的初始點(diǎn)位置。一般由彈性元件、減振器和導(dǎo)向元件組成。

　　

【正文】 over a bump and gets pushed upward, the spring absorbs that additional load, keeps the road shock from reaching the chassis, and makes sure the tire maintains contact with the pavement[3]. ng presses or extends is determined by its spring rate. Spring rate is measured in pounds per inch of deflection。 for example, 100 pounds per inch. So, say a load of 200 pounds is applied, the spring will deflect 2 inches. Spring rate es from various factors. For a coil spring, this includes the number of active coils, the diameter of the coils, and the diameter of the spring wire. The fewer coils a spring has, the higher the spring rate it will have. The design of a spring affects how well the vehicle will ride and handle. A spring that absorbs lots of energy will generally offer a fortable ride. After all, it can absorb most of the road shock (energy) that is being generated by the road surface. But there are always engineering tradeoffs. This kind of spring generally requires a higher vehicle ride height, which will cause the vehicle to feel unstable during cornering. This instability is because the more distance a spring presses or extends, the more the vehicle rolls around on its suspension. This rolling is called weight transfer, and it is caused by centrifugal force acting on the weight of the vehicle as it goes around a corner. Weight transfer can overload a tire39。s grip, which ultimately hurts traction, and therefore handling[1]. Shock Absorbers The other main part of a car39。s suspension is the shock absorber. Contrary to its name, a shock absorber plays a minimal role in absorbing impacts taken by the suspension. That39。s the spring39。s job. A shock absorber dampens road impacts by converting the up and down oscillations of the spring into thermal energy. Shock absorbers work in two cycles the pression cycle and the extension cycle. The pression cycle occurs as the piston moves downward, pressing the hydraulic fluid in the chamber below the piston. The extension cycle occurs as the piston moves toward the top of the pressure tube, pressing the fluid in the chamber above the piston. A typical car or light truck will have more resistance during its extension cycle than its pression cycle. With that in mind, the pression cycle controls the motion of the vehicle39。s unsprung weight, while extension controls the heavier, sprung weight[2]. People who live and breathe shock absorbers don39。t like the term shock absorbers。 they prefer dampers. The unwashed masses that39。s you and me just call them shock absorbers. Without a shock absorber, a spring that has absorbed energy will release it by oscillating at an uncontrolled rate. The spring39。s inertia causes it to bounce and overextend itself. Then it represses, but again travels too far. The spring continues to bounce at its natural frequency until all the energy originally put into the spring is used up by friction. This effect can be quite detrimental to the stability of a vehicle[3]. Confused? OK, here39。s an analogy. If you have a Slinky lying around and who doesn39。t these days? you can use it as an example[2]. Hold up a pressed Slinky in the air with your hand. Now hold just one end and let the other drop. The Slinky will absorb the potential energy caused by gravity (just like how a car39。s spring absorbs road shock) and then bounce up and down, up and down (aka: oscillate), for a long time. This what an automotive spring does if it doesn39。t have a shock absorber attached to it. Perhaps you39。ve heard the word strut, or, more formally, MacPherson strut. Struts are simply shock absorbers used as major structural members. For struts, the shock absorber is placed inside the coil spring. In addition to saving space, it often costs less. Many cars use a strut and struts help control how fast the suspension is allowed to move, which is important for keeping the tires in contact with the road. Most shock absorber designs have more resistance during the extension (rebound) cycle than the pression cycle[6]. This is because the extension cycle controls the motion of the vehicle39。s sprung weight (half of the suspension and everything else above the suspension) [4]. The pression cycle, on the other hand, controls the motion of unsprung weight (wheels, tires, brakes, and half of the suspension). Obviously, there is a lot more weight in the upper part of the car than unsprung weight in the lower part of the car. All modern shock absorbers are velocitysensitive the faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat. Antisway Bars Antisway bars (also known as antiroll bars) are used along with shock absorbers or struts to give a moving automobile additional stability. An antisway bar is a metal rod that spans the entire axle and effectively joins each side of the suspension together. When the suspension at one wheel moves up and down, the antisway bar transfers movement to the other wheel. This creates a more level ride and reduces vehicle sway[5]. In particular, it bats the roll of a car on its suspension as it corners. For this reason, almost all cars today are fitted with antisway bars as standard equipment, although if they39。re not, kits make it easy to install the bars at any time. So there you have it the basics of automotive suspension. We realize this is a simplistic view of a plex system. The Future of Car Suspensions While there have been enhancements and improvements to both springs and shock absorbers, the basic design of car suspensions has not undergone a significant evolution over the years. But all of that39。s about to change with the introduction of a brandnew suspension design conceived by Bose the same Bose known for its innovations in acousti