【正文】 116120124128132136140144148152156160164168172176180184188192196200圖62 優(yōu)化前轉(zhuǎn)角關(guān)系圖63 優(yōu)化后轉(zhuǎn)角關(guān)系通過梯形參數(shù)的試湊調(diào)整，內(nèi)外輪轉(zhuǎn)角度數(shù)從優(yōu)化前變化到了優(yōu)化后的效果，并將其數(shù)據(jù)與曲線直接導(dǎo)入excel表格，并在excel中作出阿克曼理論轉(zhuǎn)角關(guān)系，如圖62和63，紅色為阿克曼理論曲線，藍(lán)色為實(shí)際轉(zhuǎn)向關(guān)系曲線，從圖中可以明顯看出兩條曲線有原來的重合度較小，變成了優(yōu)化后的重合度較高。167。 基于UG工程圖模塊的轉(zhuǎn)向機(jī)動圖根據(jù)賽車的整體參數(shù)以及我們設(shè)計(jì)轉(zhuǎn)向系統(tǒng)轉(zhuǎn)角關(guān)系以及阿克曼理論，分別畫出以前外輪、前內(nèi)輪以及汽車縱向?qū)ΨQ面的轉(zhuǎn)彎半徑，然后根據(jù)給定的賽道畫出前外輪和后內(nèi)輪轉(zhuǎn)向圓以及賽道圓，由于此次大賽賽道尚未確定，我們只對初定賽道外徑檢查車尾是否會撞到安全樁，如圖64所示，由圖可知賽車車尾不會撞到安全樁。圖64 轉(zhuǎn)向機(jī)動圖167。 UG模型以及基于UG高級仿真的零部件校核采用UG參數(shù)化建模技術(shù)，建立可改性較高的轉(zhuǎn)向三維模型，如圖666,然后采用UG高級仿真功能，對建立的轉(zhuǎn)向橫拉桿模型進(jìn)行畫網(wǎng)格，并添加與實(shí)際相符的約束，施以與實(shí)際相符的外力，求解后處理后如圖67所示，強(qiáng)度滿足設(shè)計(jì)要求。圖65轉(zhuǎn)向機(jī)模型 圖66 轉(zhuǎn)向系統(tǒng)裝配圖 圖67轉(zhuǎn)向橫拉桿強(qiáng)度校核結(jié)果167。 UG裝配模型檢查干涉問題首先我們將轉(zhuǎn)向于懸架模型安裝于車架上，總共裝了三種狀態(tài)，一種是原始狀態(tài)，另外兩種狀態(tài)分別是輪胎上跳到最大位置時(shí)和輪胎向下跳動到最大位置時(shí)，裝配效果如下圖所示。 圖68 原始狀態(tài) 圖69 輪胎上跳 圖610 輪胎下跳總圖中可以看到三種極限狀態(tài)下，轉(zhuǎn)向于懸架系統(tǒng)為發(fā)生干涉現(xiàn)象，能滿足要求。第七章 結(jié)論本次設(shè)計(jì)首先采用傳統(tǒng)的設(shè)計(jì)方法設(shè)計(jì)賽車轉(zhuǎn)向系統(tǒng)，然后嘗試以UG軟件為工具，探索出一整套新的較為快捷的轉(zhuǎn)向系統(tǒng)設(shè)計(jì)方法。通過兩種方法的嘗試充分感受到新方法效率高，且通過結(jié)果對比發(fā)現(xiàn)新方法與傳統(tǒng)方法結(jié)果相符，說明新方法基本可行。本次設(shè)計(jì)主要完成的工作： 參考國內(nèi)外SAE賽車轉(zhuǎn)向系統(tǒng)結(jié)合各種形式轉(zhuǎn)向器的優(yōu)缺點(diǎn)，選定齒輪齒條式轉(zhuǎn)向器，然后通過受力分析綜合轉(zhuǎn)向性能確定轉(zhuǎn)向系統(tǒng)的傳動比，初步確定轉(zhuǎn)向器的傳動比，進(jìn)行轉(zhuǎn)向器的設(shè)計(jì)與計(jì)算。其中與商用車的主要區(qū)別是賽車傳動比較小，設(shè)計(jì)中主要考慮了轉(zhuǎn)向靈敏與轉(zhuǎn)向輕便的協(xié)調(diào)。 采用傳統(tǒng)的方法進(jìn)行轉(zhuǎn)向梯形的設(shè)計(jì)，采用MATLAB編程的方法對轉(zhuǎn)向梯形進(jìn)行優(yōu)化設(shè)計(jì) 用UG運(yùn)動仿真進(jìn)行轉(zhuǎn)向梯形的設(shè)計(jì)與優(yōu)化，并用UG建立三維實(shí)體裝配模型，進(jìn)行預(yù)裝配，實(shí)現(xiàn)轉(zhuǎn)向系統(tǒng)基本運(yùn)動關(guān)系，并檢查干涉情況與其他配合件的安裝位置 采用UG工程圖模塊繪制轉(zhuǎn)向機(jī)動圖，檢查轉(zhuǎn)彎半徑以及過彎時(shí)與車道邊緣安全樁相撞情況，采用UG高級仿真進(jìn)行某些零部件強(qiáng)度校核通過以上設(shè)計(jì)發(fā)現(xiàn)，該設(shè)計(jì)滿足參賽要求。本次設(shè)計(jì)存在的不足之處是由于時(shí)間原因，在設(shè)計(jì)過程中都是運(yùn)動學(xué)分析，沒有涉及動力學(xué)，還未采用ADAMS柔性體單元建立轉(zhuǎn)向系統(tǒng)模型，進(jìn)行仿真設(shè)計(jì)。下次設(shè)計(jì)可以在這些方面加以完善改進(jìn)。參考文獻(xiàn)[1] ：清華大學(xué)出版社,2000[2](第三版). 北京：機(jī)械工業(yè)出版社,2000 [3](下冊). 北京：機(jī)械工業(yè)出版社,2005[4] 北京：機(jī)械工業(yè)出版社,2005 [5]（新版）. 北京：機(jī)械工業(yè)出版社,2004 [6]. 北京：人民交通出版社,2001 [7][日].. 北京：機(jī)械工業(yè)出版社,1996 [8] . 北京：高等教育出版社,1991[9]：科學(xué)技術(shù)出版社,2001 [10],1986[11]：高等教育出版社,2006 [12] [13]（標(biāo)準(zhǔn)件篇）.吉林科技大學(xué)出版社，2000[14] William . . SAE[15]居小凡. Formula SAE賽車的設(shè)計(jì)制造及測試,上海交通大學(xué)碩士論文[16] 張敏中. 齒輪—齒條式轉(zhuǎn)向器轉(zhuǎn)向梯形機(jī)構(gòu)優(yōu)化設(shè)計(jì),1994年,第15期,[17] ，2005[18] Unigraphics Solutions ：清華大學(xué)出版社,2002[19]，2003年，第26期，[20]，2007年 [21]David Tremayne. The Science of Formula1 Design,2004致 謝本次畢業(yè)設(shè)計(jì)是在牛毅、郗建國、李忠利老師的認(rèn)真指導(dǎo)下完成的。在此次設(shè)計(jì)論文完成之際，我衷心的感謝三位老師在學(xué)習(xí)上的幫助。在此次課題設(shè)計(jì)當(dāng)中，三位老師提出了許多寶貴的意見，使我受益匪淺，在此向三位老師表示最衷心的感謝！在做論文的過程中，參閱了國內(nèi)外相關(guān)文獻(xiàn)資料，并引用了其中部分成果。謹(jǐn)向這些相關(guān)文獻(xiàn)資料的作者表示衷心的感謝！由于知識水平有限，本論文可能存在諸多不合理之處，以及隨著新技術(shù)的不斷發(fā)展，造成論文有一定的局限性，希望閱者批評指正。同時(shí)也要感謝學(xué)校學(xué)院的所有老師，特別是張文春、徐銳良、彭巧勵等老師，讓我學(xué)到了很多道理和知識，在此一并表示感謝。感謝車隊(duì)的同學(xué)們，正是在你們的幫助關(guān)心下，讓我順利完成畢業(yè)設(shè)計(jì)。最后，向所有關(guān)心和幫助過我的人致以最衷心的感謝！外文資料及翻譯CHAPTER 19 Steering systemIntroductionThis chapter begins with a discussion of steering geometrycaster angle,trail,kingpin inclination,and scrub next section discusses Ackemann geometry followed by steering racks and steer（bump steer）and roll steer are closely related to each other,without pliance they would be the ,wheel alignment is chapter is tied to Chapter 17 on Suspension Geometrywhen designing a new chassis,steering and suspension geometry considerations are high priorities. GeometryThe kingpin in a solid front axle is the steering modern independent suspensions,introduced by Maurice Olly at Cadillac in 1932,the kingpin is replaced by two (or more) ball joints that that define the steering axis is not vertical or centered on the tire contact patch for a number of Figure to clarify how kingpin location is measured.In front view,the angle is called kingpin inclination and the offset of the steering axis from the center of the tire print measured along the ground is called scrub (or scrub radius).The distance from the kingpin axis to the wheel center plane,measured horizontally at axle height,is the spindle length.In side view the kingpin angle is called caster angle。if the kingpin axis does not pass through the wheel center then side view kingpin offset is present,as in most motorcycle front distance measured offset is present,as in most motorcycle front distance measured on the ground from the steering axis to the center of the tire print is the trail (called caster offset in )Kingpin Front View GeometryAs mentioned in Chapter 17,kingpin inclination,spindle length,and scrub are usually a promise between packaging and performance factors to consider include:1. With a positive spindle length(virtually every car is positive as shown in Figure )the car will be raised up as the wheels are steered away from center.The more the kingpin inclination is tilted from vertical the more the car will be raised when the front wheels are effect always raises the car,regardless of which direction the wheel is steered,unless the kingpin inclination is true effect is symmetric side to side only if there is nocaster the following sectiong on Caster Angle.For a given kingpin inclination,a lenger positive spindle length will increase the amount of lift with steer.2. The effect of kingpin inclination and spindle length in raising the front end ,by itself,is to aid centering of the steering at low high speed any trail will probably swamp out the effect that rise and fall have on centering.3. Kingpin inclination affects the steercamber a wheel is steered,it will lean out at the top,toward positive camber,if the kingpin is inclined in the normal direction(toward the center of the car at the upper end).Positive camber results for both beft and rightband amount of this effect is small, but significant if the track includes tight turns.4. When a wheel in rolling over a bumpy road,the rolling radius is constantly changing,resulting in changes of wheel rotation gives rise to longitudinal forces at the wheel reaction of these forces will introduce kickback into the steering in proportion to the spindle the spindle length is zero then there will be no kick from this changes made in the last model of the GM”p”car(Fiero) shortened the spindle length and this resulted in less wheel kickback on rough roads when pared to early model”p” cars.5. The scrub radius shown in Figure is negative,as used on frontwheeldrive cars (s