摘 要曲軸是發(fā)動機的重要零件。它可以是有若干個相互錯開一定角度的曲柄（或曲拐）加上功率輸出端和自由端構(gòu)成的。每個曲柄又是由主軸頸、曲柄銷及曲柄臂組成。曲軸的作用是把活塞的往復(fù)直線運動變成旋轉(zhuǎn)運動，將作用在活塞的氣體壓力變成扭矩，用來驅(qū)動工作機械和發(fā)動機各輔助系統(tǒng)進行工作，曲軸在工作時承受著不斷變化的力，慣性力和它們的力矩作用，受力情況十分復(fù)雜。其精度要求非常高，它的加工質(zhì)量對內(nèi)燃機的工作性能，對裝配勞動量都有很大影響。因此，各要素的尺寸精度，位置精度和表面質(zhì)量要求相當高。曲軸中幾個主要加工表面，連桿表面，軸承軸頸及錐面鍵槽的精度要求都較高，連桿軸頸需經(jīng)過拋光，所以研究曲軸加工工藝及夾具設(shè)計對曲軸的生產(chǎn)具有一定的實際意義。本課題是根據(jù)被加工曲軸的技術(shù)要求，進行機械加工工藝規(guī)程設(shè)計，然后運用夾具設(shè)計的基本方法，擬定夾具設(shè)計方案，完成夾具結(jié)構(gòu)設(shè)計。主要工作有：繪制產(chǎn)品零件圖，了解零件的結(jié)構(gòu)特點和技術(shù)要求，根據(jù)生產(chǎn)類型和所在企業(yè)的生產(chǎn)條件，對零件進行結(jié)構(gòu)分析和工藝分析，確定毛坯的種類及制造方法；擬定零件的機械加工工藝過程，選擇各工序的切削用量和工時定額；填寫機械加工工藝過程卡片，機械加工工序卡片等；設(shè)計并繪制指定的專用夾具的裝配總圖和主要零件圖。關(guān)鍵詞：曲軸、主軸頸、曲拐AbstrcatThe crankshaft is one of the important parts of diesel engine. It could be several staggered Angle of crank (or crank) plus the power output end and free end. Each of the cranks is composed of main journal, crank pin and crank arm. Crankshaft is the function of the reciprocating linear motion of the piston into rotary motion, the effect on piston gas pressure become torque, work used to drive machinery and diesel engine work of auxiliary systems, each crankshaft under changing at work force, inertia force and the moment, stress distribution is very complex. Its accuracy is very high, its processing quality of the performance of internal combustion engine, labor has a great influence on assembly. As a result, the size precision of each factor, high position precision and surface quality requirement. Surface of a few main processing surface in the crankshaft, connecting rod, bearing journal and cone keyway accuracy is higher, connecting rod shaft neck should be after polishing, so the processing technology of crankshaft crankshaft production has a certain practical significance.This topic is according to the requirements of the crankshaft processed technology, carries on the machining process planning design, and then by using the basic method of fixture design, draw up jig design, fixture design. Main work includes: map parts, understand the structure features and technical requirements of the parts, and depending on the type of production in the enterprise production conditions, structural analysis and process analysis of parts, determine the type and manufacturing method of blank; To formulate parts machining process, selection of cutting parameter of each process and task time; Fill in the machining process card, machining process card, etc.; Special fixture design and draw the specified in the general layout and main assembly parts diagram.Keywords: crankshaft, main journal ,crank