【正文】 初步選取本貨車主簧的片數(shù)為13片，副簧的片數(shù)為8片。（2） 鋼板彈簧長度的初步選定：根據(jù)經(jīng)驗L = ，并結(jié)合國內(nèi)外貨車資料，初步選定主簧主片的長度為1530mm , 副簧主片的長度為1100mm.：（1） 鋼板彈簧斷面寬度b的確定：有關(guān)鋼板彈簧的剛度，強度可按等截面的簡支梁計算，引入撓度增大系數(shù)加以修正。后鋼板彈簧通過銷、前支架與車架相連接，形成固定旋轉(zhuǎn)支承端；后卷耳通過吊耳銷、吊耳、支架銷和后支架與車架連接，形成擺動旋轉(zhuǎn)支承端。如果能量的耗散僅僅是在壓縮行程或者在伸張行程進(jìn)行，則把這種減振器稱為單向作用式減振器；反之稱為雙向作用式減振器。L=Lz=4050=1280mm（3）. 鋼板斷面尺寸及片數(shù)的確定1）鋼板斷面寬度b的確定 鋼板彈簧的總慣性矩JoJo （33）式中，s—U形螺栓中心距，s=110mmk—U形螺栓夾緊彈簧后的無效長度系數(shù)，k=c—鋼板彈簧垂直剛度，c= Fw1/ fc1=9895/80=123(N/mm)δ—撓度增大系數(shù), δ=（先確定與主片等長的重疊片n1 ，在估計一個總片數(shù)n0 ，求的η= n1 / n0 ,然后用δ=[(1+)]初定δ）E—材料的彈性模量，E=105MPaJo=[（110）3123]/(48105)=31327mm2 鋼板彈簧總截面系數(shù)WoWo≥[Fw1(Lks)/(4[σw])] （34）式中，[σw]—許用彎曲應(yīng)力，[σw]=350～450MPaWo≥[9895(110)/(4350)]=8658剛板彈簧的平均厚度hp （35） =10mm推薦片寬與厚度的比值在610范圍內(nèi)選取。 減振器為液力雙作用筒式減振器。其懸架的彈性特性曲線圖22 主、副簧為鋼板彈簧結(jié)構(gòu)的彈性特性曲線如圖22所示。根據(jù)懸架在整車中的作用和整車的性能要求，懸架首先應(yīng)保證有良好的行駛平順性，這是確定懸架主要性能參數(shù)的重要依據(jù)。 （2）堅固耐用，適合重載。 懸架的側(cè)傾角剛度及前后匹配是影響汽車操縱穩(wěn)定性的重要參數(shù)。車身振動的固有頻率應(yīng)接近或處于人體適應(yīng)的頻率范圍，才能滿足舒適性要求。種類有單桿式或多連桿式的。在后懸架系統(tǒng)設(shè)計中主要對主副鋼板彈簧進(jìn)行了設(shè)計。 Leaf spring?，F(xiàn)代汽車中的懸架有兩種，一種是從動懸架，另一種是主動懸架。另外，當(dāng)懸架剛度一定時，簧載質(zhì)量越大，懸架垂直變形也愈大，而固有頻率越低。第二章 懸架系統(tǒng)的結(jié)構(gòu)與分析懸架系統(tǒng)功能很多，主要有以下幾點：(1) 對不平路面所造成的汽車行駛中的各種顫動和搖擺還有振動等，與 輪胎一起，予以吸收和減緩，從而保證乘客和貨物的安全，并提高駕駛穩(wěn)定性。這樣使得發(fā)動機可放低安裝，有利于降低汽車重心，并使結(jié)構(gòu)緊湊。因現(xiàn)代汽車的質(zhì)量分配系數(shù)ε近似等于1，于是汽車前、后軸上方車身兩點的振動不存在聯(lián)系。CA1091貨車車身側(cè)傾角選為6o。縱置鋼板彈簧能傳遞各種力和力矩，并且結(jié)構(gòu)簡單，故選用在CA1091貨車上。AB線與各葉片上側(cè)邊的交點即決定了各片長度。筒式減振器又分為單筒式和雙筒式和充氣筒式三種。 使副簧開始起作用時的懸架撓度等于汽車空載時懸架的撓度，而使副簧開始起作用前一瞬間的撓度等于滿載時懸架的撓度。 對于主簧： L=1530mm k= S=110mm =1 =13 = E=將上述數(shù)據(jù)代入以上公式得=計算主簧總截面系數(shù)： 式中為許用彎曲應(yīng)力。由圖2確定主簧各片長度：圖2 確定主簧各片長度圖主簧各片鋼板的長度如表1：序號1234567長度（mm） 1530 1093 序號8910111213長度（mm） 547 表1 主簧各片鋼板的長由圖3確定副簧各片長度圖3 確定副簧各片長度圖副簧各片鋼板的長度如表2： 序號1234567長度（mm） 1100 976 605 序號8長度（mm） 表2 副簧各片鋼板的長度3 鋼板彈簧剛度的驗算在此之前，有關(guān)撓度增大系數(shù)，總慣性矩，片長和葉片端部的形狀都不夠準(zhǔn)確，所以有必要驗算剛度。對于具有副簧的懸架，驗算強度時應(yīng)按主、副簧所受的實際載荷計算，主、副簧的參數(shù)應(yīng)取驗算后的實際值，剛度應(yīng)取夾緊剛度。中級轎車平順性分析通常研究人體的全身振動。暴露極限通常作為人體可以承受振動量的上限。圖4—2 懸架動撓度的幅頻特性曲線圖通過分析，當(dāng)阻尼比時，本懸架系統(tǒng)的平順性特性較好，符合ISO026311：1997 （E）標(biāo)準(zhǔn)。 參考文獻(xiàn)[1] 劉惟信主編. 汽車設(shè)計. 清華大學(xué)出版社, 2001[2] 曾慶東主編. 機動車減振器設(shè)計. 北京：機械工業(yè)出版社, 2000[3] 霍爾德曼. 汽車操縱和懸架系統(tǒng). 中國社會勞動出版社，[4] 張洪欣. 汽車行駛平順性計算機預(yù)測. 汽車工程，1986[5] 齊志鵬. 汽車懸架和轉(zhuǎn)向系統(tǒng)的結(jié)構(gòu)原理與檢修. 北京：人民郵電出版社，2000[6] 張正智. 中國轎車叢書. 北京：北京理工大學(xué)學(xué)報，[7] 龔為寒. 汽車現(xiàn)代設(shè)計制造. 北京：人民交通出版社，[8] 曹永堂. 汽車底盤維修. 北京：人民交通出版設(shè)，1999.[9] 屠衛(wèi)星. 汽車底盤構(gòu)造與維修. 北京：人民交通出版社，[10] 孫方寧. 汽車懸架非線性系統(tǒng)響應(yīng)分析. 長春：吉林工業(yè)大學(xué)學(xué)報，[11] 郭孔輝. 汽車懸架設(shè)計與底盤平臺相關(guān)技術(shù). 2004..8[12] 劉惟信. 機械最優(yōu)化設(shè)計. 北京：清華大學(xué)出版社, 1990[13] 林寧主編. 汽車設(shè)計. 機械工業(yè)出版社，1999[14] 楊維和主編. 汽車構(gòu)造. 北京：人民交通出版社，1998[15] 趙學(xué)敏. 汽車底盤構(gòu)造與維修. 國防工業(yè)出版社，[16] YU F.,Crolla ., Leaf spring to the independent suspension design and analysis ，Vehicle Suspension Dynamic，1998[17] Griffin，. Evaluation of vibration with respect to human response. Warrendale PA: SAE paper 860047致 謝這次設(shè)計是在遼寧工業(yè)大學(xué)單鵬老師的悉心指導(dǎo)下完成的。當(dāng)車輪通過凸起的路面時，控制臂向上運動壓縮彈簧。這種類型的連接，當(dāng)車輪來回轉(zhuǎn)動時還可以左右運動。搖臂桿與車架橫構(gòu)件之間采用橡膠襯套以便降低噪聲和衰減振動。螺旋彈簧普遍應(yīng)用在長短臂懸架系統(tǒng)中。這個十字軸依次與車架脫離。s natural resistance to twisting quickly restores it to its original position, returning the wheel to the road.A torsion bar can store a significantly higher maximum amount of energy than either an equally stressed leaf or coil spring. The torsion offers important weight savings and it is adjustable. In addition, it requires significantly less space than a coil spring.The leaf spring is made of several layers of spring steel stacked one upon the other, Usually, there is one main leaf that uses spring eyes for locating and fastening the spring toe frame or underbody. Several other progressively shorter leaves are placed on the main leaf, and the assembly or leaf pack is held together in the middle by a center bolt and on the ends by rebound clips. Some spring packs use fiber. or plastic pads between leaves to reduce the internal leaf friction. Some vehicles use a single leaf instead of a buildup of multiple leaves. One manufacturer is using a leaf spring manufactured from a nonmetal posite. Leaf springs are usually arched so that the ends are higher than the center when viewed from the side.The leaf spring is usually mounted in three places. A bushing is installed in each of the spring eyes. A bolt through the bushing in the rear spring eye attaches the rear of the spring directly to the vehicle frame. A shackle assembly is attached to the front spring eye and bushing and is then mounted through a shackle bushing to the frame. The shackle assembly allows the leaf spring to pivot up and down. A pair of Ubolts and a tie plate are used to clamp the front or rear axle assembly to the leaf spring.The main advantage of leaf springs is their ability to control vehicle sway and lateral movement. For these reasons, leaf springs are often used on the rear suspension of rear drive vehicles.Many latemodel luxury cars use air springs. The spring is essentially a rubber bag or bladder full of air. A piston is attached to the lower control arm. Movement of the lower control arm causes the piston to move into the air bladder and press the air in the bladder. Air pressure is used to regulate how easy or hard the bladder can be pressed. The air bladder is usually connected to an air pressor, which regulates the action of the air spring based on road conditions.All suspension systems use a shock absorber at each wheel. When the coil, torsion bar, leaf spring, or air spring is deflected, it can oscillate (bounce up and down) uncontrollably, possibly causing the tires to lose contact with the road. This could cause the car to bounce up and down without any control. To prevent thi