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第 1 頁 理工科類 本科生畢業(yè)設(shè)計 論文 開題報告 論文 設(shè)計 題目 辛普森變速器的結(jié)構(gòu)設(shè)計 作者所在系別 機電工程學(xué)院 作者所在專業(yè) 車輛工程 作者所在班級 B13142 作 者 姓 名 高家寶 作 者 學(xué) 號 201322393 指導(dǎo)教師姓名 焦運景 指導(dǎo)教師職稱 副高 完 成 時 間 2017 年 3 月 北華航天工業(yè)學(xué)院教務(wù)處制 第 2 頁 說 明 1 根據(jù)學(xué)校 畢業(yè)設(shè)計 論文 工作暫行規(guī)定 學(xué)生必須撰寫 畢業(yè) 設(shè)計 論文 開題報告 開題報告作為畢業(yè)設(shè)計 論文 答辯委員會對學(xué) 生答辯資格審查的依據(jù)材料之一 2 開題報告應(yīng)在指導(dǎo)教師指導(dǎo)下 由學(xué)生在畢業(yè)設(shè)計 論文 工作前 期內(nèi)完成 經(jīng)指導(dǎo)教師簽署意見及所在專業(yè)教研室論證審查后生效 開題 報告不合格者需重做 3 畢業(yè)設(shè)計開題報告各項內(nèi)容要實事求是 逐條認(rèn)真填寫 其中的文 字表達要明確 嚴(yán)謹(jǐn) 語言通順 外來語要同時用原文和中文表達 第一 次出現(xiàn)縮寫詞 須注出全稱 4 開題報告中除最后一頁外均由學(xué)生填寫 填寫各欄目時可根據(jù)內(nèi)容 另加附頁 5 閱讀的主要參考文獻應(yīng)在 10 篇以上 土建類專業(yè)文獻篇數(shù)可酌減 其中外文資料應(yīng)占一定比例 本學(xué)科的基礎(chǔ)和專業(yè)課教材一般不應(yīng)列為 參考資料 6 參考文獻的書寫應(yīng)遵循畢業(yè)設(shè)計 論文 撰寫規(guī)范要求 7 開題報告應(yīng)與文獻綜述 一篇外文譯文和外文原文復(fù)印件同時提交 文獻綜述的撰寫格式按畢業(yè)設(shè)計 論文 撰寫規(guī)范的要求 字?jǐn)?shù)在 2000 字 左右 畢業(yè)設(shè)計 論文 開題報告 學(xué)生姓名 高家寶 專 業(yè) 車輛工程 班 級 B13142 指導(dǎo)教師姓名 焦運景 職 稱 副高 工作單位 北華航天工業(yè)學(xué)院 課題來源 教師自擬課題 課題性質(zhì) 應(yīng)用設(shè)計 課題名稱 辛普森變速器結(jié)構(gòu)設(shè)計 本設(shè)計的科學(xué) 依據(jù) 科學(xué)意義和 應(yīng)用前景 國 內(nèi)外研究概況 目前技術(shù)現(xiàn)狀 水平和發(fā)展趨 勢等 1 辛普森變速器研究的依據(jù)與意義 汽車工業(yè)作為一個國家的支柱產(chǎn)業(yè) 對國家的經(jīng)濟發(fā)展有著舉足輕重的 作用 從 19 世紀(jì)末卡爾本茨制造出的第一輛汽車到今天的智能型多功 能汽車 汽車以從單純的代步工具發(fā)展成為現(xiàn)代社會的象征 汽車工業(yè) 發(fā)展水平 家庭平均擁有汽車數(shù)量以及公路網(wǎng)的建設(shè)規(guī)模等已經(jīng)成為衡 量一個國家工業(yè)發(fā)達程度的重要標(biāo)志 在當(dāng)今一些發(fā)達的國家 其汽車 工業(yè)的發(fā)展更是對國家經(jīng)濟發(fā)展社會進步有著直接的影響 二 辛普森變速器的國內(nèi)外研究概況 目前 從市場上不同車型所配置的變速器來看 變速器主要分為以 下幾種 1 手動變速器 手動變速器采用齒輪組 每檔的齒輪組德齒數(shù)是固定的 所以各檔 的變速比是個定值 2 自動變速器 自動變速器 利用行星齒輪機構(gòu)進行變速 它能根據(jù)油門踏板程度 和車速變化 自動地進行變速 而駕駛者只需操縱加速踏板控制車速即 可 雖說自動變速器沒有離合器 但自動變速器中有很多離合器 這些 離合器能隨車速變化自動分離或閉合 從而達到自動變速的目的 3 無級變速器 無級變速器系統(tǒng)不像手動變速器那樣用齒輪變速 而是用兩個滑輪 和一個剛帶來變速 其傳動比可以隨意變化 沒有換擋的突跳感覺 它 能克服普通自動變速器突然換擋 油門反應(yīng)慢 油耗高等缺點 無級變 速器能在一定范圍內(nèi)實現(xiàn)速比的無極變換 并選定幾個常用的速比作為 常用的檔 裝配該技術(shù)的發(fā)動機可在任何轉(zhuǎn)速下自動獲得最合適的傳動 比 三 汽車節(jié)能技術(shù)現(xiàn)狀和發(fā)展趨勢 綠色汽車 節(jié)能減排已經(jīng)成為當(dāng)今汽車工業(yè)發(fā)展的主旋律 未來新 能源汽車的應(yīng)用與車輛 智能化 結(jié)合 也是汽車工業(yè)發(fā)展的方向 發(fā) 達國家車輛變速器發(fā)展?fàn)顩r和需求各有特點 手動與自動并存 不同地 域需求比例不同 國內(nèi)變速器主要以手動擋為主 自動變速器占有率正 在快速提升 設(shè)計內(nèi)容和預(yù) 期成果 具體設(shè)計內(nèi) 容和重點解決 的技術(shù)問題 預(yù)期成果和提 供的形式 一 辛普森變速器的結(jié)構(gòu)設(shè)計 首先經(jīng)過實體拆裝 然后測量出所需數(shù)據(jù) 應(yīng)用三維繪圖軟件繪制 實體圖 完成零部件二維圖的繪制及尺寸標(biāo)注 一張 0 號裝配圖 若干 零部件圖 擬采取設(shè)計方 法和技術(shù)支持 設(shè)計方案 技術(shù)要求 實 驗方法和步驟 可能遇到的問 題和解決辦法 等 1 設(shè)計方法 查閱資料 變速器的參數(shù)并運用 caxa solidworks 畫出產(chǎn)品的零 件圖和裝配圖 2 可能遇到的問題 若制動系統(tǒng)設(shè)計不正確 可以請教老師 若裝配圖有問題 可以查閱資料或請教同學(xué) 實現(xiàn)本項目已 具備的條件 包括過去學(xué) 習(xí) 研究工作 基礎(chǔ) 現(xiàn)有主 要儀器設(shè)備 設(shè)計環(huán)境及協(xié) 作條件等 汽車設(shè)計參數(shù)可參考相關(guān)書籍自己擬定 各環(huán)節(jié)擬定階 段性工作進度 以周為單位 1 4 周 完成開題報告 5 6 周 查閱資料 確定設(shè)計方案 7 8 周 計算所需參數(shù) 9 10 周 畫出各個零件圖和裝配圖 11 12 周 轉(zhuǎn)向和制動系統(tǒng)測試 13 14 周 細(xì)節(jié)工作 準(zhǔn)備答辯 開 題 報 告 審 定 紀(jì) 要 時 間 地點 主持人 姓 名 職 務(wù) 職 稱 姓 名 職 務(wù) 職 稱 參 會 教 師 論 證 情 況 摘 要 記錄人 指 導(dǎo) 教 師 意 見 指導(dǎo)教師簽名 年 月 日 教 研 室 意 見 教研室主任簽名 年 月 日 本科生畢業(yè)設(shè)計 論文 文獻綜述 設(shè)計 論文 題目 辛普森變速器圖形繪制 作者所在系別 機電工程學(xué)院 作者所在專業(yè) 車輛工程 作者所在班級 B13142 作 者 姓 名 高家寶 作 者 學(xué) 號 201322393 指導(dǎo)教師姓名 焦運景 指導(dǎo)教師職稱 副高 完 成 時 間 2017 年 3 月 北華航天工業(yè)學(xué)院教務(wù)處制 說 明 1 根據(jù)學(xué)校 畢業(yè)設(shè)計 論文 工作暫行規(guī)定 學(xué)生必須撰寫畢業(yè)設(shè)計 論文 文獻綜述 文獻綜述作為畢業(yè)設(shè)計 論文 答辯委員會對學(xué)生答辯資格 審查的依據(jù)材料之一 2 文獻綜述應(yīng)在指導(dǎo)教師指導(dǎo)下 由學(xué)生在畢業(yè)設(shè)計 論文 工作前期 內(nèi)完成 由指導(dǎo)教師簽署意見并經(jīng)所在專業(yè)教研室審查 3 文獻綜述各項內(nèi)容要實事求是 文字表達要明確 嚴(yán)謹(jǐn) 語言通順 外來語要同時用原文和中文表達 第一次出現(xiàn)縮寫詞 須注出全稱 4 學(xué)生撰寫文獻綜述 閱讀的主要參考文獻應(yīng)在 10 篇以上 土建類 專業(yè)文獻篇數(shù)可酌減 其中外文資料應(yīng)占一定比例 本學(xué)科的基礎(chǔ)和專業(yè) 課教材一般不應(yīng)列為參考資料 5 文獻綜述的撰寫格式按畢業(yè)設(shè)計 論文 撰寫規(guī)范的要求 字?jǐn)?shù)在 2000 字左右 文獻綜述應(yīng)與開題報告同時提交 0 畢 業(yè) 設(shè) 計 論 文 文 獻 綜 述 文獻綜述題目 摘要 辛普森式自動變速器的動力分析是工學(xué)結(jié)合一體化課程 汽車自動變速器維修工作頁 的教學(xué)重點 也是難點 如何引導(dǎo)學(xué)生開展這一任務(wù)的學(xué)習(xí) 對培養(yǎng)學(xué)生對自動變速器 的學(xué)習(xí)興趣和提高學(xué)生的學(xué)習(xí)積極性有著至關(guān)重要的作用 應(yīng)該遵循 在做中學(xué) 的理 念 在工作頁的指引下 合理設(shè)置目標(biāo)和配置資源 保持工作過程系統(tǒng)化 有機實施教 學(xué)計劃 展開教學(xué)過程 關(guān)鍵詞 辛普森 動力分析 教學(xué)資源 學(xué)習(xí)領(lǐng)域 工作過程 Abstract The dynamics analysis of Simpson automatic transmission is a teaching focus and difficult point of Repair of Automobile Automatic transmission course How to guide students to carry out the learning of this mission plays a pivotal role in cultivating students interest and activeness in learning automatic transmission By adhering to the concept of learning in doing teachers should properly set purpose and resources keep systematic working process and properly carry out teaching plan Keyword Simpson dynamics analysis teaching resource learning field working process 1 引言 自動變速器的檢修 是汽車專業(yè)教學(xué)的核心課程之一 是實踐性很強的綜合技術(shù)學(xué)科 涵 蓋了機械 液壓 電控等諸多領(lǐng)域 具有技術(shù)要點多 知識覆蓋面廣的特點 要求具有 很強的邏輯思維能力 靈巧的動手能力 歸納總結(jié)能力 同時 由于結(jié)構(gòu)和原理的相對 復(fù)雜性 在教學(xué)中 學(xué)生往往難以理解和接受 如何分析和解決故障也就成了教學(xué)最大 的難點 因此 需要建立一種有效的實現(xiàn)工作過程系統(tǒng)化的教學(xué)模式 采用一體化教學(xué) 形式 讓學(xué)生多參與 勤動手 ?？偨Y(jié) 學(xué)會學(xué)習(xí) 作為老師 需要合理制訂教學(xué)計劃 精心組織實施計劃 做到由易到難 從簡到繁 有機地將學(xué)習(xí)任務(wù)串接起來 只有這樣 才能高效地讓學(xué)生掌握自動變速器的結(jié)構(gòu) 工作原理以及檢修等方面的知識和技能 1 一 課題的作用 熟悉辛普森變速器 以及能應(yīng)用三維繪圖軟件 繪制其三維實體圖 在三維實體的 基礎(chǔ)上 繪制其零部件的二維圖 二 研究現(xiàn)狀 1 單排行星齒輪運動機構(gòu)的特點與運動規(guī)律 認(rèn)識單排行星齒輪運動機構(gòu)的結(jié)構(gòu)特點 重點理解行星齒輪的自轉(zhuǎn)和公轉(zhuǎn)運動 明 白行星架運動的實質(zhì)就是行星齒輪的公轉(zhuǎn) 行星齒輪自轉(zhuǎn)的時候卻并不一定公轉(zhuǎn) 因此 行星架可以被約束固定 但是行星齒輪是不能受到任何約束的 2 典型辛普森行星齒輪機構(gòu)的結(jié)構(gòu)特點 在單排行星齒輪機構(gòu)的基礎(chǔ)之上 引入雙排行星齒輪機構(gòu) 由學(xué)生自己通過觀察之 后 請學(xué)生代表講解前 后排行星齒輪機構(gòu)之間的彼此位置關(guān)系 引導(dǎo)學(xué)生正確理解典 型辛普森行星齒輪機構(gòu)的結(jié)構(gòu)特點 得出結(jié)論 其實只要稍作引導(dǎo) 學(xué)生基本上就可以 看出端倪 前 后排太陽輪在一根軸上 屬于共用太陽輪 而前排行星架與后排的齒圈 是相連的 且連接到輸出軸 作為動力的輸出端 3 執(zhí)行元件的結(jié)構(gòu)特點 工作原理及拆檢 在單排行星齒輪機構(gòu)運動規(guī)律的學(xué)習(xí)中 學(xué)生已經(jīng)知道有齒輪被固定 也有齒輪作 為主 從動件的情況 那么這些由我們?nèi)藶樵O(shè)置的約束條件在變速器內(nèi)部實際是如何實現(xiàn) 的呢 通過查閱資料 分組討論 在老師的引導(dǎo)下 合理引出執(zhí)行元件離合器 制動器 單向離合器 在接下來的學(xué)習(xí)中需要讓學(xué)生學(xué)習(xí) 理解這常用的三種執(zhí)行元件的結(jié)構(gòu)特點 工作原理并實施拆檢工作 重點在于濕式多片離合器與制動器的異同 鋼片及摩擦片的安 裝連接位置 單向離合器這一機械元件有別于離合器及制動器這些液壓工作元件 單向離 合器 內(nèi)不動則外動或者外不動則內(nèi)動 的結(jié)構(gòu)特點 其實 這些都可以在教師的引導(dǎo)下 由學(xué)生分組獨立完成 2 三 目前研究存在的問題 齒輪傳動系統(tǒng)的振動不僅會產(chǎn)生噪聲 導(dǎo)致傳動系統(tǒng)的不穩(wěn)定 而且由于振動的加 劇 會導(dǎo)致磨損 疲勞破壞 實際運動規(guī)律偏離理論運動規(guī)律等問題 從而發(fā)生誤差 降低機器工作的安全性 可靠性和工作質(zhì)量 甚至導(dǎo)致車輛或者其它零件的破壞 使傳 動系統(tǒng)失效從而發(fā)生嚴(yán)重的后果 因此近些年來對齒輪傳動系統(tǒng)動態(tài)性能的研究備受關(guān) 注 本文選題源自汽車自動變速器關(guān)鍵零部件及技術(shù)研究項目 項目所研究的自動變速 器采用的齒輪具有模數(shù)不是標(biāo)準(zhǔn)模數(shù) 變位量和螺旋角大三個特點 行星齒輪機構(gòu)是自 動變速器的核心機構(gòu) 齒輪的設(shè)計必須要有可靠的依據(jù) 研究齒輪參數(shù)對齒輪系統(tǒng)甚至 整個自動變速器的動力學(xué)性能以及開發(fā)設(shè)計自動變速器齒輪傳動系統(tǒng)具有重要的意義 在項目組研究課題的支持下 本文對四擋辛普森式自動變速器的齒輪傳動部分進行了仿 真和分析 主要研究了齒輪參數(shù) 模數(shù) 螺旋角 變位量等 對四擋辛普森式行星齒輪 系統(tǒng)的動力學(xué)性能的影響規(guī)律 參考文獻 1 唐文初 鄧寶清主編汽車構(gòu)造 M 廣州 華南理工大學(xué)出版社 2010 2 葛安林 自動變速器 一 自動變速器綜述 J 汽車技術(shù) 2001 5 1 3 3 黃安華 岳強 楊世鐵 現(xiàn)代汽車的自動變速器技術(shù)及應(yīng)用 J 汽車工程師 2009 9 54 56 4 劉巖東編著 汽車自動變速器構(gòu)造與原理解析 M 北京 機械工業(yè)出版社 2010 5 王洋 鄭暉 王育欣 自動變速器發(fā)展情況及前景 J 信息科學(xué)與工程技術(shù) 102 108 6 羅時帥 考慮動靜態(tài)特性的汽車 AT 機械傳動系統(tǒng)齒輪變位系數(shù)研究 機械設(shè)計及 理論 2011 7 葛安林 車輛自動變速理論與設(shè)計 M 北京 機械工業(yè)出版設(shè) 1993 8 胡光輝 仇雅莉編著 汽車自動變速器原理與檢修 M 北京 機械工業(yè)出版社 2006 9 黃康 曾億山 汽車自動變速技術(shù)的發(fā)展現(xiàn)狀 J 合肥工業(yè)大學(xué)學(xué)報 自然科學(xué)版 2005 28 12 1503 1507 10 張炳力 趙韓 金朝勇 朱可 汽車自動變速器研究現(xiàn)狀及展望 J 中國機械工 程 2006 17 417 420 3 畢 業(yè) 設(shè) 計 論 文 文 獻 綜 述 指導(dǎo)教師意見 指導(dǎo)教師 年 月 日 專業(yè)教研室審查意見 負(fù)責(zé)人 年 月 日 密 級 分類號 編 號 成 績 本科生畢業(yè)設(shè)計 論文 外 文 翻 譯 原 文 標(biāo) 題 自動變速器 譯 文 標(biāo) 題 AUTOMATIC TRANSMISSION 作者所在系別 機電工程學(xué)院 作者所在專業(yè) 車輛工程 作者所在班級 B13142 作 者 姓 名 高家寶 作 者 學(xué) 號 201322393 指導(dǎo)教師姓名 焦運景 指導(dǎo)教師職稱 副高 完 成 時 間 2017 年 3 月 共 6 頁 第 1 頁 譯文標(biāo)題 自動變速器 原文標(biāo)題 AUTOMATIC TRANSMISSION 作 者 譯 名 國 籍 原文出處 共 6 頁 第 2 頁 The modern automatic transmission is by far the most complicated mechanical component in today s automobile It is a type of transmission that sifts itself A fluid coupling or torque converter is used instead of a manually operated clutch to connect the transmission to the engine There are two basic types of automatic transmission based on whether the vehicle is rear wheel drive or front wheel drive On a rear wheel drive car the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position A drive shaft connects the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels Power flow on this system is simple and straight forward going from the engine through the torque converter then trough the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear transmission On a front wheel drive car the transmission is usually combined with the final drive to form what is called a transaxle The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car Front axles are connected directly to the transaxle and provide power to front wheels In this example power floes from the engine through the torque converter to a larger chain that sends the power through a 180 degree turn to the transmission that is along side the engine From there the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular A much less popular rear and is connected by a drive shaft to the torque converter which is still mounted on the engine This system is found on the new Corvette and is used in order to balance the weight evenly between the 共 6 頁 第 3 頁 front and rear wheels for improved performance and handling Another rear drive system mounts everything the engine transmission and final drive in the rear This rear engine arrangement is popular on the Porsche The modern automatic transmission consists of many components and systems that designed to work together in a symphony of planetary gear sets the hydraulic system seals and gaskets the torque converter the governor and the modulator or throttle cable and computer controls that has evolved over the years into what many mechanical inclined individuals consider to be an art from Here try to used simple generic explanation where possible to describe these systems 1 Planetary gear sets Automatic transmission contain many gears in various combinations In a manual transmission gears slide along shafts as you move the shift lever from one position to another engaging various sizes gears as required in order to provide the correct gear ratio In an automatic transmission how ever the gears are never physically moved and are always engaged to the same gears This is accomplished through the use of planetary gear sets The basic planetary gear set consists of a sun gear a ring and two or more planet gears all remaining in constant mesh The planet gears are connected to each other through a common carrier which allows the gears to spin on shafts called pinions which are attached to the carrier One example of a way that this system can be used is by connecting the ring gear to the input shaft coming from the engine connecting the planet carrier to the output shaft and locking the sun gear so that it can t move In this scenario when we turn the ring gear the planets will walk along the sun gear which is held stationary causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing 共 6 頁 第 4 頁 gear reduction similar to a car in first gear If we unlock the sun gear and lock any two elements together this will cause all three elements to turn at the same speed so that to output shaft will turn at the same rate of speed as the input shaft This is like a car that is third or high gear Another way we can use a planetary gear set is by locking the planet carrier from moving then applying power to the ring gear which will cause the sun gear to turn in opposite direction giving us reverse gear The illustration in Figure shows how the simple system described above would look in an actual transmission The input shaft is connected to the ring gear the output shaft is connected to the planet carrier which is also connected to a Multi disk clutch pack The sun gear is connected to drum which is also connected to the other half of the clutch pack Surrounding the outside of the drum is a band that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning The clutch pack is used in this instance to lock the planet carrier with the sun gear forcing both to turn at the same speed If both the clutch pack and the band were released the system would be in neutral Turning the input shaft would turn the planet gears against the sun gear but since noting is holding the sun gear it will just spin free and have no effect on the output shaft To place the unit in first gear the band is applied to hold the sun gear from moving To shift from first to high gear the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft Many more combinations are possible using two or more planetary sets connected in various way to provide the different forward speeds and reverse that are found in modern automatic transmission 2 Clutch pack A clutch pack consists of alternating disks that fit inside a clutch drum Half of the disks are steel and have splines that fit 共 6 頁 第 5 頁 into groves on the inside of the drum The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one 共 6 頁 第 6 頁 3 Torque Converter On automatic transmission the torque converter takes the place of the clutch found on standard shift vehicles It is there to allow the engine to continue running when the vehicle comes to a stop The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan which is unplugged If you grab the blade on the unplugged fan you are able to hold it from turning but as soon as you let go it will begin to speed up until it comes close to speed of the powered fan The difference with a torque converter is that instead of using air it used oil or transmission fluid to be more precise A torque converter is a lager doughnut shaped device that is mounted between the engine and the transmission It consists of three internal elements that work together to transmit power to the transmission The three elements of the torque converter are the pump the Turbine and the Stator The pump is mounted directly to the torque housing which in turn is bolted directly to the engine s crankshaft and turns at engine speed The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle The stator is mounted to a one way clutch so that it can spin freely in one direction but not in the other Each of the three elements has fins mounted in them to precisely direct the flow of oil through the converter With the engine running transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section which stars it running The fluid continues in a circular motion back towards the center of the turbine where it enters the stator If the turbine is moving considerably slower than the pump the fluid will make contact with the front of the stator fins which push the stator into the one way clutch and prevent it from turning With the stator stopped the fluid is directed by the stator fins to re enter the pump at a help angle providing a torque increase As the speed of the turbine catches up with the pump the fluid starts hitting the stator blades on the back side causing the stator to turn in 共 6 頁 第 7 頁 the same direction as the pump and turbine As the speed increase all three elements begin to turn at approximately the same speed Sine the 80s in order to improve fuel economy torque converters have been equipped with a lockup clutch which locks the turbine to the pump as the vehicle reaches approximately 40 50 mph This lockup is controlled by computer and usually won t engage unless the transmission is in 3rd or 4th gear 共 6 頁 第 8 頁 4 Hydraulic System The hydraulic system is a complex maze of passage and tubes that sends that sends transmission fluid and under pressure to all parts of the transmission and torque converter and Transmission fluid serves a number of purpose including shift control general lubrication and transmission cooling Unlike the engine which uses oil primary for lubrication every aspect of a transmission s function is dependant on a constant supply of fluid is send pressure In order to keep the transmission at normal operating temperature a portion of the fluid is send to through one of two steel tubes to a special chamber that is submerged in anti freeze in the radiator Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube A typical transmission has an avenge of ten quarts of fluid between the transmission torque converter and cooler tank In fact most of the components of a transmission are constantly submerged in fluid including the clutch packs and bands The friction surfaces on these parts are designed to operate properly only when they are submerged in oil 5 Oil Pump The transmission oil pump not to confused with the pump element inside the torque converter is responsible for producing all the oil pressure that is required in the transmission The oil pump is mounted to front of the transmission case and is directly connected to a flange on the engine crankshaft the pump will produce pressure whenever the engine is running as there is a sufficient amount of transmission fluid available The oil enters the pump through a filter that is located at bottom of the transmission oil pan and travels up a pickup tube directly to the oil pump The oil is then sent under pressure to the pressure regulator the valve body and the rest of the components as required 6 Valve Body The valve body is the control center of the automatic transmission It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves which when activate the appropriate clutch pack of 共 6 頁 第 9 頁 band servo to smoothly shift to the appropriate gear for each driving situation Each of the many valves in the valve body has a specific purpose and is named for that function For example the shift valve activates the 2nd gear up shift or the shift timing valve which determines when a downshift should occur The most important valve and the one that you have direct control over is the manual valve The manual valve is directly connected to the gear shift handle and covers and uncovers various passages depending on what position the gear shift is paced in When you place the gear shift in Drive for instance the manual valve directs fluid to the clutch pack s that activates 1st gear It also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1 2 shift On computer controlled transmission you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points 7 Computer Controls The computer uses sensors on the engine and transmission to detect such things as throttle position vehicle speed engine speed engine load stop light switch position etc to control exact shift points as well as how soft or firm the shift should be Some computerized transmission even learn your driving style and constantly adapt to it so that every shift is timed precisely when you would need it Because of computer controls sports models are coming out with the ability to take manual control of the transmission as through it were a stick shift lever through a special gate then tapping it in one direction or the other in order to up shift at will The computer monitors this activity to make sure that the driver dose not select a gear that could over speed the engine and damage it Another advantage to these smart transmission is that they have a self diagnostic mode which can detect a problem early on and warn you with an indicator light on the dash A technician can then plug test equipment in and retrieve a list of trouble codes that will help pinpoint 共 6 頁 第 10 頁 where the problem is 共 6 頁 第 11 頁 指 導(dǎo) 教 師 評 語 共 6 頁 第 12 頁 外文翻譯成績 指導(dǎo)教師簽字 年 月 日 注 1 指導(dǎo)教師對譯文進行評閱時應(yīng)注意以下幾個方面 翻譯的外文文獻與畢業(yè)設(shè)計 論文 的主題 是否高度相關(guān) 并作為外文參考文獻列入畢業(yè)設(shè)計 論文 的參考文獻 翻譯的外文文獻字?jǐn)?shù) 是否達到規(guī)定數(shù)量 3 000 字以上 譯文語言是否準(zhǔn)確 通順 具有參考價值 共 6 頁 第 13 頁 2 外文原文應(yīng)以附件的方式置于譯文之后