工程制图开放实验二指导书.doc

工程图学与虚拟设计实验室工程制图开放实验二指导书图样画法徒手绘制创新设计构型图样2007年1月 实验二 图样画法徒手绘制创新设计构型图样一、实验目的 Objective为加强自主动手能力、创新思维能力培养，通过实践教学，学习图样画法的方法及技巧，掌握各种表达方法，徒手绘制创新设计构型的图样，有意识地培养学生的专业兴趣，增强空间想象思维能力，激发学生的创新设计潜能，达到对学生自主动手能力、创新思维能力、空间想象思维能力、分析问题和解决问题能力及徒手作图能力的培养目的。By the practice of freehand sketching, students master skills and various kinds of representation methods of mechanical parts and structures, and improve their abilities of representation and freehand sketching.二、 实验要求 Requirements1、 学习视图的概念及国标规定。Study the concepts of views and related national standards.2、 学习徒手表达三维形体的绘图方法和技能。Study the methods of freehand sketching.3、 掌握绘图规范及国标要求。Master the construction methods of sections.4、 掌握对形体进行分析的方法。Master the construction methods of cuts.5、 掌握形体的合理表达方法。Master common simplified and conventional representations三、 实验内容 Contents1徒手绘制一张“构型积木”在包装盒内的原始摆放位置平面图；Draw a plan of the original positions of a box of “configuration building blocks” by free sketching.2利用“构型积木”自选题模仿实物形状及功能，进行自主创新构型设计；Carry out creative design using “configuration building blocks”, simulating real object shapes and functions.3运用“形体分析方法”对所设计的构型结构进行分析；Analyze the structure of the configuration using “Shape and Structure Analysis Method”.4确定合理的表达方案，并徒手绘制出其三视图。求将所设计的产品图样画在A3#图纸上。Decide a reasonable representation scheme and draw the three-view of the design by freehand sketching.四、 实验指导徒手绘图方法与技巧 Methods and Skills of Freehand Sketching徒手图也称草图，是不借助绘图工具用目测形状及大小徒手绘制的图样。在机器测绘、讨论设计方案、技术交流、现场参观时，受现场或时间限制，通常只绘制草图。Freehand, or sketch, is a drawing method by which shapes and sizes of objects are obtained by ocular estimate method and drawings are created without help of drawing tools. Sketches are often used in the stages of machine mapping, scheme design, technological exchange and so on. 画草图的要求是 Requirements（1）画线要稳，图线要清晰；Lines should be clear;（2）目测尺寸要尽量准，各部分比例匀称；Sizes obtained by ocular estimate method should be exact and parts should be shapely.（3）绘图速度要快；Drawing speed should be fast.（4）标注尺寸无误，书写清楚。Dimensions should be correct and clear. 徒手绘图方法 Skills要画好草图，必须掌握徒手绘制各种线条的基本手法。Some basic skills of freehand sketching should be mastered.（1）握笔方法 the way of holding pencil 手握笔的位置要比用仪器绘图时高些，以利运笔和观察目标。笔杆与纸面4560角，执笔稳而有力。The pencil should be hold tightly the holding position should be higher than drawing tools. The angle between the penholder and the paper is 4560.（2）直线的画法 drawing a straight line 画直线时，手腕靠着纸面，沿着画线方向移动，保持图线稳直。眼要注意终点方向。 When draw a straight line, put the wrist on the paper and move along the line, keeping the line straight. 画垂直线时自上而下运笔；画水平线自左而右的画线方向最为顺手，这时图纸可放斜；斜线一般不太好画，故画图时可以转动图纸，使欲画的斜线正好处于顺手方向。画短线，常以手腕运笔，画长线则以手臂动作。为便于控制图大小比例和各图形间的关系，可利用方格纸画草图。Generally, the moving direction of the pencil is from the top down for a vertical line while from the left rightward for a horizontal line. For an oblique line, one can turn the paper so that the movement of the wrist is comfortable during drawing. When draw a short line, only wrist needs to move, while for a long line, wrist have to move together with the arm. In order to control the scale properly, squared paper can be used.（3）圆的画法 drawing a circle 画圆时，应先定圆心位置，过圆心画对称中心线，在对称中心线上距圆心等于半径处截取四点，过四点画圆即可。To draw a circle, circle center is decided first and then symmetrical center lines are drawn passing through the center point. Pick up four points on the center lines whose distances to the center points are the radius of the circle. By these four points, a circle can be easily drawn. 画稍大的圆时可再加一对十字线并同样截取四点，过八点画圆。If a circle is large, one may need to pick up more points, 8 points for instance, on the center lines. （4）曲线的画法 Drawing a curve 对于圆角、椭圆及圆弧连接，也是尽量利用与正方形、长方形、菱形相切的特点画出。Try to draw curves by keeping them tangent with some auxiliary squares, rectangles or rhombuses. 绘制草图步骤 Steps of freehand sketchinga） 在图纸上定出各视图的位置 Decide the positions of views 画出各视图的基准线、中心线。安排各视图的位置时，要考虑到各视图间应有标注尺寸的地方，右下角留有标题栏的位置。Draw base lines and center lines of views. Before doing this, the positions of the views should be decided, with the space left for dimensions and title bar.b） 详细地画出所设计构型外部和内部的结构形状。Draw structural shapes in detail.c） 选择基准和画尺寸线、尺寸界线及箭头。过仔细校核后，描深轮廓线，画好剖面线。Sel