【正文】 1 畢 業(yè) 論 文 （科 學(xué) 研 究 報(bào) 告） 題 目 汽車(chē)發(fā)動(dòng)機(jī)四缸曲軸加工工藝 及夾具設(shè)計(jì) 院 (系 )別 機(jī)電及自動(dòng)化學(xué)院 專(zhuān) 業(yè) 機(jī)械工程及自動(dòng)化 級(jí) 別 2021 學(xué) 號(hào) ***** 姓 名 *** 指導(dǎo)老師 *** 副 教授 ** 大 學(xué) 教 務(wù) 處 2021 年 6 月 I 摘 要 曲軸是汽車(chē)發(fā)動(dòng)機(jī)的重要零件。它的作用是把活塞的往復(fù)直線運(yùn)動(dòng)變成傳動(dòng)軸的旋轉(zhuǎn)運(yùn)動(dòng)，將作用在活塞的氣體壓力變成扭矩，用來(lái)驅(qū)動(dòng)工作 機(jī)械和發(fā)動(dòng)機(jī)各輔助系統(tǒng)進(jìn)行工作。曲軸在工作時(shí)承受著不斷變化的壓力、慣性力和它們的力矩作用，因此要求曲軸具有強(qiáng)度高、剛度大、耐磨性好，軸頸表面加工的尺寸精確，且潤(rùn)滑可靠。 本設(shè)計(jì)是根據(jù)被加工曲軸的技術(shù)要求 ，進(jìn)行機(jī)械工藝規(guī)程的設(shè)計(jì)，然后運(yùn)用夾具設(shè)計(jì)基本原理和方法，擬定夾具設(shè)計(jì)方案，完成夾具結(jié)構(gòu)設(shè)計(jì)。主要工作有：繪制產(chǎn)品零件圖，了解零件結(jié)構(gòu)特點(diǎn)和技術(shù)要求；根據(jù)生產(chǎn)類(lèi)型和所在企業(yè)生產(chǎn)條件，對(duì)零件進(jìn)行結(jié)構(gòu)分析及工藝分析；確定毛坯種類(lèi)及制造方法；擬定零件機(jī)械加工工藝過(guò)程，選擇各工序的加工設(shè)備與工藝設(shè)備，確定各工序的加工 余量與工序尺寸，計(jì)算各工序的切削用量與工時(shí)定額；填寫(xiě)機(jī)械加工工藝過(guò)程卡片、機(jī)械加工工序卡片等工藝卡片；設(shè)計(jì)指定的專(zhuān)用夾具，繪制裝配總圖和主要零件圖。 本次設(shè)計(jì)主要是為了提高曲軸零件的生產(chǎn)效率，以及加工精度。因此，制定工藝路線時(shí)嚴(yán)格按照 基準(zhǔn)先行，先主后次，先粗后精，先面后孔 的工藝設(shè)計(jì)準(zhǔn)則。先加工出基準(zhǔn)，再用精基準(zhǔn)定位加工其它工序。在夾具設(shè)計(jì)時(shí)，選擇的是車(chē)曲軸連桿軸頸的工序，定位時(shí)選擇兩個(gè) V形塊和周向定位釘定位，用壓板夾緊，并且在夾具上設(shè)置合適的偏心距。 通過(guò)本次設(shè)計(jì)我查閱了許多書(shū)籍和行業(yè)資料，了解到行業(yè)的發(fā)展 進(jìn)程和部分先進(jìn)技術(shù)，擴(kuò)展了我的專(zhuān)業(yè)視野，為將來(lái)的學(xué)習(xí)生活都有著重要的影響。 關(guān)鍵詞 ： 機(jī)械制造，加工工藝，曲軸，夾具 II ABSTRACT Crankshaft is a very important parts of diesel engine. Ist action is change the to and fro straightline motion of the piston into rotary motion,and change the gas pressure on the piston into torque, that is used to drive executive body and accessory system of the diesel engine. Crankshaft is withstanding the changing pressure, inertia force and the torque. So the crankshaft mast have high strength, high rigidity, high abrasion resistance and the surface of axle journal must have high precision with well lubricating. This design is on the basis of technical requirement of the crankshaft to design the technological procedure. And then use the fundamental and method of the fixture design to fix the fixture design programme,and plete the structural of the fixture. The main work is: Parts drawing, understand the characteristic of structure and technical requirement。 Accroding to the types of manufacturing and the plant conditions of the pany we will analyse the structure and craft of the crankshaft。 Fix the type and manufacturing method of the roughcast。 Fix the processing technic of the crankshft,select device and equipment fix the machining allowance and working procedure size and count the cutting specifications and time allowance.。 Fix the Processing technological process card and Machinefinishing operation card。 Design the special fixture and plan the assembling drawing and main parts drawing. This design is in order to improve the crankshaft parts production efficiency, and the machining accuracy. Therefore,when drawing up the process we strict accordance with the design criteria that benchmark first,main first then secondary, rough first then essence, surface first ， hole after . First, work out benchmark, again with pure reference positioning processing other processes. In fixture design,I choose the car process of crankshaft connecting rod , When location,I choose two V block and circumferential locating pin to positioning, pressed powder pact, and set up appropriate eccentricity on the jig. Accroding to this design I looked through many books and industry information, understand some of the industry development process and advanced technologies,and also expanded my professional has important influence on my future study and life. KEYWORDS: Machine manufacture Processing craft Crankshaft fixture 1 目 錄 摘 要 ....................................................... I ABSTRACT .................................................... II 第一章 緒 論 ................................................ 3 設(shè)計(jì)的主要內(nèi)容 .................................................... 3 國(guó)內(nèi)外的研究現(xiàn)狀 .................................................. 3 第二章 零件分析 .............................................. 7 零件的作用 ........................................................ 7 曲軸工藝分析 ...................................................... 7 第三章 工藝規(guī)程設(shè)計(jì) .......................................... 8 確定毛坯的材料和制造形式 .......................................... 8 基面的選擇 ........................................................ 8 粗基準(zhǔn)的選擇 ........................................................................................................ 8 精基準(zhǔn)的選擇 ........................................................................................................ 8 制定工藝路線 ...................................................... 8 工藝路線方案 ...................................................... 9 機(jī)械加工余量、工序尺寸及毛坯尺寸的確定 ........................... 10 確定加工余量 ...................................................................................................... 10 確定工序尺寸及其公差 .........................................................................................11 加工余量計(jì)算 .......................................................................................................11 確定主要工序的切削用量及基本工時(shí) ................................. 16 第四章 專(zhuān)用夾具設(shè)計(jì) ......................................... 37 設(shè)計(jì)主旨 ......................................................... 37 需要解決的主要問(wèn)題 ............................................... 37 形狀復(fù)雜 ............................................................................................................. 37 剛性差 ................................................................................................................ 37 技術(shù)要求高 ......................................................................................................... 37 確定夾具設(shè)計(jì)方案 ................................................. 38 選擇定位基準(zhǔn)，并確定工件的定位方式及定位元件的結(jié)構(gòu) ................................... 38 確定工件的夾緊方式，選擇合適的夾緊機(jī)構(gòu) ........................................................ 38 確定銑床夾具與機(jī)床間的正確位置 ...................................................................... 39 夾緊力的計(jì)算 ..................................................... 39 切削力的計(jì)算 ...................................................................................................... 39