东北大学工程图学第二版 1

工程图学,工程图学教学与研究中心Engineeringgraphicsteachingandresearchcenter,EngineeringDrawing,Office:机械实验楼207Tel-mail:shnisun,工程图学,EngineeringDrawing,自秦汉起，我国已出现图样的史料记载，并能根据图样建筑宫室。宋代李诫(仲明)所著营造法式一书，附有大量的建筑图样。全书36卷中有8卷是图样(包括平面图、轴测图、透视图)。,developmentandapplicationofengineeringdrawing,绪论Preface,工程图样是制造机器、仪器和进行工程施工的主要依据，是工程技术人员进行技术交流的重要工具，是工程界的“技术语言”。从手工绘图到计算机绘图，从二维工程制图到三维造型设计，从三维造型设计到计算机辅助分析、制造随着制造业的飞速发展，制图技术将进一步得到推广应用,DesignofBuilding,Worldexpo2010shanghai,shanghaiexpoaxis,索膜工程钢结构设计图,Robot,Figuredesignofmobilephone,Computer,icebox,TV,etc.,Design,manufactureandprocessing,Designandmachiningofcar,Spaceshuttle,Drawingsareneededinanysystem,virtualrealitytechnology,simulationandanalysis,Processing,MechanicalManufacturing,ConstructionDesign,simulation,etc.allneeddrawings.,model（三维形状表达）,drawing（二维投影表达）,东北大学,图样承载信息,形状信息尺寸信息质量信息,工业加工、机械制造、工程施工设计、模拟、仿真都离不开图样,绪论Preface,一、课程的内容和任务Thecontentsandtasksofthiscourse,工程图样被称为工程界的语言。Engineeringdrawingsarecalledthelanguageoftheengineering.1.课程的主要内容Themaincontentsofthiscourse投影理论Projectiontheories制图标准Drawingstandards计算机绘图Computergraphics绘图技法Drawingskills,2.课程要完成的主要任务Themaintasksofthiscourse(1)培养绘制和阅读工程图样的能力。Trainingtheabilitytodrawandreadtheengineeringdrawings.(2)掌握正投影法的基本理论。Masteringthebasictheoriesoforthography.(3)培养空间形象思维和解决空间几何问题的基本能力。Trainingtheabilitytovisualizeorthinkandsolvegeometryproblemsinthreedimensions.(4)培养态度认真、作风严谨的独立工作能力。Improvingindependentworkingabilityofearnestattitudeandprecisestyle.,学会什么？,二、本课程的学习方法Proposalsforstudyingthiscourse1.会听课，听好课。Beingagoodlistener.2.理论联系实际，注意提高空间想象能力。Theorycombinespractice,improvingtheabilitytovisualizeorthink.3.带着问题学习，提倡研究性学习，培养创新能力。Studywithquestions.Advocatetheinquirylearning，encourageinnovation.4.认真完成课程中的实践环节及作业，忌眼高手低。Practicalworksandhomeworkshouldbecompletedconsciously.认真按时完成小作业（习题集）和白图（尺规绘图）作业。使用绘图工具,5.严格遵守机械制图的国家标准，学会查阅有关标准和资料。Strictlyobservethedrawingstandards,beingabletoconsultstandardsandreferences.,怎么学？,第2章投影法与工程图Chapter2ProjectionmethodandEngineeringDrawing,2-1投影法的基本知识BasicKnowledgeofProjectionMethods,2-2常见工程图CommonEngineeringDrawing,A,B,C,a,b,c,S,投射中心Projectioncenter,投射线通过物体，向特定的投影面投射，并在该投影面上得到图形的方法叫做投影法。Themethodthat,whentheprojectionlinepassthroughtheobject,itsprojectionisprojectedontoaspecificprojectionplane,iscalledprojectionmethod.,投影Projection,21投影法的基本知识,2-1投影法的基本知识BasicKnowledgeofProjectionMethods,一、投影法的基本概念BasicConceptionofProjectionMethods,21投影法的基本知识,二、投影法的种类Thetypesofprojectionmethods,1中心投影法投射线汇交于一点的投影法。CentralProjectionMethod,21投影法的基本知识,2平行投影法所有投射线都互相平行的投影法。ParallelProjectionMethod,(1)斜投影法投射线与投影面倾斜Obliqueprojectionmethod,(2)正投影法投射线与投影面垂直OrthographicProjectionMethod,投影法PM,中心投影法CentralPM,平行投影法ParallelPM,正投影法：SPOrthographicPM,21投影法的基本知识,正投影法的基本理论是工程制图的基础。Theorthographicprojectionmethodtheoryisthebasementofengineeringdrawings.,二、投影法的种类Thetypesofprojectionmethods,1.积聚性Thecharacteristicofaccumulation,3.类似性ThecharacteristicofSimilarity,2.真实性Thecharacteristicoftrueness,21投影法的基本知识,三、正投影的基本性质Basiccharacteristicsoftheorthographicprojection,正投影基本性质举例Exampleofbasiccharacteristicsoftheorthographicprojection,积聚性Accumulation真实性Trueness类似性Similarity,21投影法的基本知识,一.透视图PerspectiveProjectionDrawings二.轴测图AxonometricDrawings三.标高投影图ProjectionDrawingofElevation四.三视图TheViewsinThreeDirections,22常见工程图,2-2常见工程图CommonEngineeringDrawings,轴测图,A,a,b,B1,B2,单面投影：点不定位，体不定形,22常见工程图,三面视图TheViewsinThreeDirections,一、视图的基本概念Thebasicconceptsofviews,用正投影法所绘制的物体投影图称为视图。Theprojectiondrawingconstructedbyorthographicprojectionmethodiscalledtheview.,Onlyoneprojectiondoesntdefinethepositionofapointinspace，nordoestheshapeofanobject.,O,22常见工程图,二、三视图的形成Formationofthethreeviews,1.三投影面体系的建立Settingupofthethree-viewprojectionsystem,正立投影面（V面）FrontalProjectionplane(planeV),水平投影面（H面）HorizontalProjectionPlane(planeH),侧立投影面（W面）ProfileProjectionplane(planeW),VH=OX轴,VW=OZ轴,HW=OY轴,两投影面相交，其交线称为投影轴。Theintersectinglineoftwoprojectionplanesiscalledtheprojectionaxis.,X,Y,Z,O,FrontView主视图,TopView俯视图,LeftSideView左视图,前Front,22常见工程图,俯视图（水平投影）TopView,主视图(正面投影)FrontView,左视图（侧面投影）LeftSideView,2.三视图的形成Formationofthreeviews,22常见工程图,3.三视图的展开Developmentofthreeviews,O,V,W,X,Z,YH,YW,H,22常见工程图,4.展开后的三视图Thedevelopedthreeviews,边框和投影轴不必画出Theframesandprojectionaxesintheviewsdontneedtobedrawn.,22常见工程图,长度,宽度,高度,问题：物体运动，三视图如何动？Therelationshipbetweenmovementofthreeviewsandobject.,1.三视图的位置关系Thepositionalrelationshipsofthreeviews.,三、三视图间的投影规律Projectionprinciplesofthreeviews,左Left,右Right,前Front,后Rear,上Top,下Bottom,前Front,后Rear,左Left,右Right,上Top,下Bottom,宽,宽,22常见工程图,主、俯视图长对正;Thefrontviewandthetopviewalllineupverticallyandarethesamewidth.,主、左视图高平齐;Thefrontviewandtheleftsideviewalllineuphorizontallyandarethesameheight.,俯、左视图宽相等。Thetopviewandtheleftsideviewareallequidistantfromtherespectivefoldinglinesandarethesamedepth.,三、三视图间的投影规律Projectionprinciplesofthreeviews,此为“三等规律”。Thisisthe“three-equalrules”.,（a）选择图示方向为主视图的投影方向，画出各视图的定位线,（b）根据正投影法的真实性，按实际长度和高度画出主视图,（c）根据主俯视图长对正，结合实际宽度画出俯视图,（d）根据“高平齐，宽相等”画出左视图。不可见的轮廓线画成虚线,（e）描深可见轮廓线，完成,线型问题Aboutthelinestyle,1.分析形体，自然安放Analyzetheshapeofanobject,反映特征、减少虚线,2.先主后俯，选择主视方向Drawthefrontview,Selecttheorientationofthefrontview,andthendrawotherviews.,3.检查、整理并加深轮廓线。Heavyinallfinallines.,四、根据物体画三视图Drawingthethreeviewsbyobjects,22常见工程图,d=0.5,0.7,0.20.3,1220，1,26,1,粗实线:可见轮廓线,细实线:尺寸线，剖面线,虚线:不可见轮廓线,细点画线：对称线，轴线,线型要