中型載重汽車底盤后懸架的設計【含CAD圖紙、說明書】

畢業(yè)設計（論文）材 料系 、 部：學生姓名：指導教師：職 稱：專 業(yè)：班 級：學 號：1材料清單1、畢業(yè)設計（論文）課題任務書2、指導教師評閱表3、答辯及最終成績評定表4、畢業(yè)設計說明書5、附錄材料6、實習日記2畢業(yè)設計（論文）課題任務書系： 機械工程系 專業(yè)： 機械制造與自動化 指導教師 學生姓名 課題名稱 中型載重汽車底盤后懸架設計內(nèi)容及任務懸架是現(xiàn)代汽車的重要總成，它把車架（或車身）與車軸（或車輪）彈性的連接起來，不僅承受和傳遞路面作用于汽車的力和力矩并產(chǎn)生位移，而且衰減路面對汽車的振動和沖擊等，從而保證汽車平穩(wěn)的行駛，貨車底盤掛車橋懸架系統(tǒng)的設計力求滿足貨車的行駛平順性，行駛安全性及操縱穩(wěn)定性等1. 盡可能降低懸架固有振動頻率2提高橫向穩(wěn)定性3提高操縱穩(wěn)定性4.足夠的強度和適當?shù)膭偠?.有良好的隔聲能力6結(jié)構(gòu)緊湊，占用空間尺寸要小3擬達到的要求或技術(shù)指標1. 盡可能降低懸架固有振動頻率2提高橫向穩(wěn)定性3提高操縱穩(wěn)定性4.足夠的強度和適當?shù)膭偠?.有良好的隔聲能力6結(jié)構(gòu)緊湊，占用空間尺寸要小7、設計應以獨立完成為主，圖紙表達要正確清晰，計算正確，能借助各種工具書和技術(shù)資料獲得所需的正確數(shù)據(jù)；8、說明書應內(nèi)容完整，字跡工整，語言簡練，文字通順。說明書中應重點包括設計方案的分析與論證，考慮問題的出發(fā)點和最后選擇的依據(jù)，必要的計算過程，其他說明等。進度安排起止日期 工作內(nèi)容 備注42012 年 2 月3 月2012 年 3 月4 月2012 年 4 月5 月2012 年 5 月布置任務，方案設計 設計計算和工藝編制結(jié)構(gòu)設計和繪圖編寫畢業(yè)設計說明書時間 1 周時間 1 周時間 1 周時間 1 周主要參考資料1 汽車工程手冊編輯委員會,汽車工程手冊.北京：人民交通出版社,20012 大連理工大學工程畫教研室,機械制圖（第四版）. 北京：高等教育出版社,19993 濮良貴,紀明剛. 機械設計（第七版）. 北京：高等教育出版社,20024 龔微寒,現(xiàn)代汽車設計制造. 北京：人民交通出版社,1995 5 王望予. 汽車設計. 北京：清華大學出版社,20016 劉惟信. 汽車設計. 北京：清華大學出版社,2002教研室意見 年 月 日系主管領(lǐng)導意見年 月 日5畢業(yè)設計（論文）指導教師評閱表系： 機械工程系 學生姓名 學 號 班 級 專 業(yè) 機械制造與自動化 指導教師姓名 課題名稱 中型載重汽車底盤后懸架設計評語：（包括以下方面，學習態(tài)度、工作量完成情況、材料的完整性和規(guī)范性；檢索和利用文獻能力、計算機應用能力；學術(shù)水平或設計水平、綜合運用知識能力和創(chuàng)新能力；）是否同意參加答辯： 是 否指導教師評定成績 分值：指導教師簽字： 年 月 日6答辯及最終成績評 定 表系（公章）： 機械工程系 說明：最終評定成績a+b，兩個成績的百分比由各系自己確定，但應控制在給定標準的 10左右。學生姓名 學號 答辯日期課題名稱 中型載重汽車底盤后懸架設計 指導教師 評 定成 績 評 定 分值 教師 1 教師 2 教師 3 教師 4 教師 5 小計課題介紹思路清晰，語言表達準確，概念清楚，論點正確，實驗方法科學，分析歸納合理，結(jié)論嚴謹，設計（論文）有應用價值。30必答題40答辯表現(xiàn)思維敏捷,回答問題有理論根據(jù)，基本概念清楚，主要問題回答準確大、深入,知識面寬。自由提問30合 計 100答 辯 評 分分值：答辯小組長簽名：答辯成績 a：40指導教師評分 分值： 指導教師評定成績 b： 60最終評定成績：分數(shù)： 等級：答辯委員會主任簽名：年 月 日外文資料譯文1懸架性能測試懸架系統(tǒng)雖不是汽車運行不可或缺的部件，但有了它人們可以獲得更佳的駕駛感受。簡單的說，它是車身與路面之見的橋梁。懸架的行程涉及到懸浮于車輪之上的車架，傳動系的相對位置。就像橫跨于舊金山海灣之上的金門大橋，它連接了海灣兩側(cè)。去掉汽車上的懸架就像是你做一次冷水潛泳通過海灣一樣，你可以平安的渡過整個秋天，但會疼痛會持續(xù)幾周之久。想想滑板吧！它直接接觸路面你可以感受到每一塊磚，裂隙及其撞擊。這簡直就是一種令人全身都為之震顫的體驗。當輪子滑過路面時，就會在此產(chǎn)生震動，沖擊，這種震動的旅程時對你的身體和勇氣的檢驗。如果你沒感到隨時都有被掀翻之勢，那么你或許會樂在其中吧！這就是你會在沒有懸架的汽車上將會體驗到的。為了道路交通安全，包括定期檢查車輛暫停行駛性能測試是順理成章的事。原型試驗結(jié)果與機載和規(guī)格提出有效懸架系統(tǒng)的測試。示威活動是由歐洲減震器制造商協(xié)會(EUSAMA)，正確運作減震器已經(jīng)引起了許多國家重視.。估計英國早在 1977 年 1 月起，環(huán)境部就進行了檢查減震器的MOT 測試?，F(xiàn)在減震器機車里的測試儀器，就其實質(zhì)效力及安全的客觀評價就沒有達到共識.。但人們認為，歐洲可能用更嚴厲的法律手段定期檢驗將來的一種客觀需求測試設備無法解釋的錯誤。自 1971 年成立，EuSAMA 就認識到了該問題的重要性，并組成了最初的技術(shù)小組，負責研究和分析測試儀器。 有兩個基本類型的機器提供了當時減震器故障診斷。包括：1. 吊機，在軸的車輪約 100 毫米處，然后讓它們落下。接著記下他們各自的位置，然后和預定的前方或后方車輛暫停位置比較。這種模擬機向前邁了一大步，并記錄了實體運動情況(參看圖 1).這些措施調(diào)動機輪，引發(fā)暫停，從上述共振頻率為零位置掃描。采用了支持平臺下的輪胎.。成績記錄結(jié)果與車輪時間不符。 同時，把車輪彈跳沉最高頻率和前方或后方的特殊車輛預定暫停位置進行比較。外文資料譯文2下面要介紹的第三種機器，通過應用組件的平臺下輪胎，引發(fā)了暫停或不斷的頻率階段措施。時刻激勵部隊記錄結(jié)果，并和特殊車輛預定的暫停位置比較。這些系統(tǒng)有三個基本的缺點：.與原來的阻尼表現(xiàn)比較而言，實際的阻尼出現(xiàn)了一定的退化。 原來的表現(xiàn)，已經(jīng)是在邊緣了。.設定上限的問題，即應該由誰來定限額的標準應該是什么呢? 目前在實踐中設定的范圍和可接受表現(xiàn)之間幾乎沒有任何關(guān)系.對不同類型的車輛的懸架系統(tǒng)和實際存在的各種各樣的中斷，它們的界限會有所差別。這就需要全面參考手冊并不斷更新。盡管該系統(tǒng)有這些根本的弊端，但是他們的根特大學實驗室工程師，以及幾位 Eusama 成員已經(jīng)開始使用測試儀器。正如所料，第一個結(jié)論是，沒有檢驗方法是可以不包括拆除汽車減震器就能夠提供有關(guān)資料和減震器單的，但實際上整個汽車停止系統(tǒng)是通過了測試.。這可以說是一個積極的方面測試，全部停止安全狀況應當是良好的； 盡管減震器最有可能進一步部分使用惡化，其他缺點如夸大輪胎，或處理破城球，如果可能的話，應給予診斷。其他影響測試結(jié)果的因素中，氣溫減震器影響所有機器給出的結(jié)果。對于下降型試驗機減震器缺陷造成的高頻激勵是不能察覺的。 頻率掃描型機器的出現(xiàn)，持續(xù)的投入意味著在用軟或硬中斷的車輛之間差別很大。因此從太空正常到重型任務的改變(操作可能無法識別)可以認為直接影響結(jié)果。每一種機器的制造都有它自己的特征，但由于基本原則，被認為是不可接受的測試不會在這里出現(xiàn)。充分考慮技術(shù)小組委員會建議 Eusama 的加入，雖然現(xiàn)有機器正確操作，可以診斷許多錯誤減震器、負責協(xié)會不能批準這種設備作為技術(shù)上代表某一方面性能的衡量參數(shù)。以剎車測試為例，指出：測試儀器直接顯示制動效率的百分比，無需辨別車型或使用參考手冊.。同樣，制動性能的最低水平也一定能為所有模式汽車使用，讓顧客立即知道剎車注意事項，有些機器顯示制動失衡，但并不表明它的某組成部分失常。運用車輛停止同樣的原則，應當可以提供測試，給出直接顯示或最好的百分比，說明從安全角度暫停是不是可取。進一步說，必須客觀的執(zhí)行，也就是說，測試者不需要任何辨別、說明、和參考手冊。外文資料譯文3因此技術(shù)小組尋找了一個合適的參數(shù)，可以視為車輛安全暫停標準。 如前所述，只有一個正常的組成部分那就是使用減震器。首先必須確定減震器的作用。它們可以實現(xiàn)兩種功能：降低車身移動和控制車輪亂跳。允許車身移動是一個很值得嘗試的問題，主要是控制這些移動，在優(yōu)化舒適方面，減震器的阻尼特性是不同的。車身的移動當然影響到交通堵塞，但實際上很少有普通司機能達到范圍內(nèi)，所以對安全措施而言，車身的阻尼特性變得不那么重要。在任何情況下，汽車阻尼性能差的司機可以很快控制速度，保證車輛的反應能力。從另一方面來說，車輪彈跳是衡量危險的一個現(xiàn)象，車輪固定不牢固的危險是眾所周知的。兩站和制動性能也是一樣。兩站的輪胎和制動性能要收到道路情況的限制； 這是依靠縱向的聯(lián)系,以及車輪輪胎資自身的性能。道路交通堵塞的一個客觀衡量標準，即車輛暫停安全性被獨立出，但是仍需能夠體現(xiàn)它可以隨時解釋。有人提議，輪胎和公路間的縱向聯(lián)系，車輪跳動次數(shù)，表示這是一個靜態(tài)的車輪負荷百分比.。這種可能性曾在會晤技術(shù)小組委員會和根特大學的 Verschoore博士討論過，并達成了一些一致意見，但是一些成員仍表示懷疑這個測量參數(shù)實用性，以及懷疑相關(guān)結(jié)果。在以后的小組中獲悉，德國機械原型大概用上述原則提出了對根特大學的評價。 某些建議進行了修改后，根特大學和 Eusama 公司成員證明了這種測試的可能性，充分證明了技術(shù)小組委員會要衡量參數(shù)的的決定。下面是有關(guān)原型機器測試的過程和測試結(jié)果，由西德的 Maschingfabrik Koppern 和 Co, Hattingen 發(fā)展，比利時布魯塞爾的門羅提出。車輪轉(zhuǎn)動是由暫停引發(fā)的，掃描頻率范圍為 025 赫茲，在輪胎下方使用，伴隨有固定 6 毫米的中風轉(zhuǎn)動。一次測試一個輪胎。計算公式：10%最 小 輪 胎 載 重靜 止 時 在 重測試者所分析的結(jié)果會通過最小輪胎受力預示展現(xiàn)出來明顯特征。注重測試時的儀器讀數(shù)和以往的實驗經(jīng)驗相匹配，因為還沒有一種科學的測試方法能夠很精確的用在道路行駛測試系統(tǒng)上最終決定車輛的行駛平順性和乘座舒適性取決于車輛制造商所做的或多或少的行駛試驗測試方法是否能行將在于懸架系統(tǒng)是否正常工作，因此，推薦仔細的檢查懸外文資料譯文4架系統(tǒng)的每一個單元以次來改進懸架測試的精確性，初始的錯誤可以經(jīng)常被找到在測試惡化之前第二，這懸架系統(tǒng)的測試，車輪與車輪之間，只有當有毛病時才表現(xiàn)出來；它并不規(guī)定這些錯誤，通過一個熟練的操作者可能從測試讀本上診斷出一些毛病很明顯在設計一個機器時我們應考慮到存在一定機率過度靜摩擦，仍然需要在這一領(lǐng)域的改進工作當加強和改進彈簧和減振器時，汽車懸架的基本設計并沒有同步進行，也沒有什么重大革命性的發(fā)展。但是這一切都隨著 BOSE 公司的懸架品牌的引入而發(fā)生改變-就是那個在聲學因發(fā)明創(chuàng)造引以為名的公司。一些專家已經(jīng)在說BOSE的懸架是自汽車技術(shù)引入全獨立懸架以來在汽車懸架的最重大的進步。它是怎么工作的呢？BOSE 的系統(tǒng)是在每一個車輪上裝一個線控電磁馬達（LEM ）以控制一組減振器和彈性元件的狀態(tài)。功率放大器提供電力對馬達在這種情況下他們的力量再生以系統(tǒng)的各壓縮。 馬達的主要好處是, 他們因具有慣性，不限制于固有的在常規(guī)基于流體的阻尼特性。所以，一個 LEM 可以在任何的速度伸張和壓縮，自然它可衰減乘員艙體的所有振動。輪子的運動可以被很好的控制，因而，在輪子的任何運動狀態(tài)車體都可以保持可以接受的狀態(tài)。LEM 同樣可以在汽車加、減速，轉(zhuǎn)彎時產(chǎn)生的傾角較小，讓駕駛員以更好的狀態(tài)駕駛汽車。外文資料譯文5Suspension performance testingThe suspension system, while not absolutely essential to the operation of a motor vehicle, makes a big difference in the amount of pleasure experienced while driving. Essentially, it acts as a “bridge“ between the occupants of the vehicle and the road they ride on. The term suspension refers to the ability of this bridge to “suspend“ a vehicles frame, body and powertrain above the wheels. Like the Golden Gate Bridge hovering over San Francisco Bay, it separates the two and keeps them apart. To remove this suspension would be like taking a cool dive from the Golden Gate: you might survive the fall, but the impact would leave you sore for weeks. Think of a skateboard. It has direct contact with the road. You feel every brick, crack, crevice and bump. Its almost a visceral experience. As the wheels growl across the pavement, picking up a bump here, a crack there, the vibration travels up your legs and settles in your gut. You could almost admit you were having fun, if you didnt feel like you were gonna toss your tacos at any second. This is what your car would feel like without a suspension system.In the interests of road safety, it is logical to include in periodic roadworthiness tests an inspection of vehicle suspension performance. The results of tests with a prototype machine are presented and a specification proposed for a valid suspension test.Demonstrations organized by the European Shock Absorbers Manufacturers Association ( EuSAMA) in many countries have drawn attention to the importance of correctly functioning shock absorbers. In the United Kingdom it is anticipate that the Department of the Environment will include a specific shock absorber check in the MOT Test with effect from January 1977.Of the machines currently available for testing shock absorbers without removing them from the vehicle, there is no real consensus of opinion concerning their validity to evaluate suspension safety objectively. But it is felt that possible more stringent legislation on European periodic vehicle tests in the future will demand a form of objective testing on equipment that is incapable of erroneous interpretation.外文資料譯文6Since its formation in 1971 EuSAMA has realized the imnportance of the problem, and initially charged its technical sub-committee with the task of examining and analyzing the various test machines then available. Two basic types of machine were offered at that time for diagnosing faulty shock absorbers. These were:Machines which lift up the wheels on an axle by about 100 mm and then let them drop. The subsequent displacements of the body on each side are recorded and the results compared with preset values for the particular vehicle and the suspension position, front or rear. Such a machine simulates a step input and records the subsequent body movements (see Fig 1).Machines which measure wheel movements induced by the exitation of the suspension through a frequency scan from above resonance frequency to zero, applied by means of a spring-supported platform under the tyre. Results are recorded in the form of wheel displacement against time. While passing through the wheel bounce resonant frequency the maximum amplitude is obtained and this is compared with preset values for the particular vehicle and the suspension position front or rear (see Fig 2).A third machine, introduced later, measures phase shift induced by the excitation of the suspension at a constant frequency and stroke, applied by means of a vibrating platform under the tyre. The phase shift between the moment of excitation and the force-reaction is recorded and the result is compared with preset values for the particular vehicle and suspension position (see Fig 3).These systems have three fundamental drawbacks:A: The actual damping is compared with the original damping the limit being a certain degradation in comparison with the original performance. The original performance, however, can already be marginal.B: The problems of limit setting, namely by whom should the limits be set and what are the criteria they should about? At present there is hardly any relation between set limits and acceptable performance in practice.C: The practical problem of various limits for different vehicle types and their suspensions. This requires comprehensive reference manuals that need continuously updating.外文資料譯文7Despite these fundamental drawbacks, examples of the ? widely used test machines were put through their paces by the Automotive Engineers Laboratory of the University of Ghent, as well as by several EuSAMA members. As expected, the first conclusion is that no test method which does not include dismantling the shock absorbers from the vehicle is able to furnish information concerning the shock absorber alone, and it is in fact the whole of the vehicle suspension system that is tested. This can be considered as a positive aspect of testing, since the whole of the suspension should be in good condition for safety; although the shock absorber is the component most likely to deteriorate with use, other defects such as incorrectly inflated tyres, broken springs or seized ball-joins should if possible be diagnosed.Of the other factors which influenced test results it was found that all machines gave results that were much affected by shock absorber temperature. In the case of the drop type testing machines, defects in shock absorbers caused by high frequency excitation could not be detected. With the frequency scan type of machine, approximately constant force input implies a big difference in results between vehicles with soft or hard suspension, so that changes in springs from normal to heavy duty (which the operator may be incapable of identifying ) can considerable affect the result.Each make of machine had its own characteristics, but as the basic test principles were considered to be unacceptable these details will not be presented here.After due consideration the technical sub-committee advised the General Assembly of EuSAMA that although the existing machines, when correctly operated, could help to diagnose many faulty shock absorbers, a responsible association could not authorize such equipment as the parameters measured were not considered technically representative of any particular aspect of roadworthiness.Taking brake testing as an example, it was noted that test machines give a direct reading of braking efficiency as a percentage of g without the need to identify vehicle type or to use reference manuals. Similarly, minimum braking performance levels can be set for all automobiles irrespective of model, so that a customer knows immediately if his brakes need attention, Some machines show brake imbalance, but do not indicate which component is faulty.Applying the same principles to vehicle suspension, it should be possible to 外文資料譯文8propose a test which furnishes a direct reading as a value or preferably as a percentage, to indicate whether a suspension is considered satisfactory from the viewpoint of safety. Moreover, this must be achieved objectively, that is to say without need of any identification, interpretation or reference to manuals by the test operator.The technical sub-committee therefore looked for a parameter which could be considered a suitable criterion of safety in relation to vehicle suspension. As stated earlier, there is only one component normally subject to deterioration with usethe shock absorber. So the role of the shock absorbers must first be defined. These have two functions to perform: to damp the movement of the vehicle body on its springs and to control wheel bounce.The permitted movement of a vehicle body on its springs is very much a matter of taste, and it is largely in the control of such movement that a sports shock absorber differs in damping characteristics from a shock absorber aimed at optimum comfort. The movement of a body on its springs does, of course, materially influence roadholding but in reality few ordinary drivers are capable of reaching the limits of the modern car in this respect, so the value of body damping is relatively unimportant for safety measurements. In any case, most drivers of a vehicle with poor body damping will quickly limit their speed and manoeuvres to the vehicles handling capacity.Wheel bounce, on the other hand, is a measurable phenomenon and the dangers of vehicles with uncertain wheel contact are well known. Both cornering and braking performance are well known. Both cornering and braking performance are limited by tyre anherence to the road; this is dependent on the vertical wheel contact as well as the tyres own properties.A parameter which permits the objective measurement of one aspect of roadholding, and therefore of vehicle suspension safety, was thus isolated but it was still necessary to be able to express it in terms that could be readily interpreted.It was proposed, therefore, to measure the minimum remaining vertical contact force between tyre and road under a given excitation at wheel-bounce frequency and to express it as a percentage of the static wheel load. Such a possibility was discussed at a meeting between the technical sub-committee and Dr Verschoore of the University of Ghent. A general concensus of opinion in favour of such a test was reached, though some 外文資料譯文9members expressed doubts concerning the possibility of measuring this parameter in practice, as well as doubts concerning the results Aparamet。.At a later date the sub-committee was informed that a prototype machine of German origin, using approximately the principle outlined above, had been submitted for evaluation to the University of Ghent. After certain recommended modifications had been performed, tests by both the University of Ghent and a member company of EuSAMA demonstrated the possibilities of such a test, and amply justified the technical sub-committees decision concerning the parameter to be measured.Details are given below of the tests performed and the results obtained on a prototype machine, developed by Maschingfabrik Koppern it will not locate the fault, though a skilled operator may be able to diagnose certain defects from the test read-out.Obviously there is a requirement to design a machine able to detect when a certain percentage of static friction is exceeded. Development work in this area is still required.外文資料譯文10While 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 thats about to change with the introduction of a brand-new suspension design conceived by Bose - the same Bose known for its innovations in acoustic technologies. Some experts are going so far as to say that the Bose suspension is the biggest advance in automobile suspensions since the introduction of an all-independent design. How does it work? The Bose system uses a linear electromagnetic motor (LEM) at each wheel in lieu of a conventional shock-and-spring setup. Amplifiers provide electricity to the motors in such a way that their power is regenerated with each compression of the system. The main benefit of the motors is that they are not limited by the inertia inherent in conventional fluid-based dampers. As a result, an LEM can extend and compress at a much greater speed, virtually eliminating all vibrations in the passenger cabin. The wheels motion can be so finely controlled that the body of the car remains level regardless of whats happening at the wheel. The LEM can also counteract the body motion of the car while accelerating, braking and cornering, giving the driver a greater sense of control. Unfortunately, this paradigm-shifting suspension wont be available until 2009, when it will be offered on one or more high-end luxury cars. Until then, drivers will have to rely on the tried-and-true suspension methods that have smoothed out bumpy rides for centuries.