nd 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、实验指导一—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 mapp ing, scheme design, techI 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 fas (4)标注尺寸无误,书写清楚。 Dimensions should be correct and clear ◆徒手绘图方法Skis 要画好草图,必须掌握徒手绘制各种线条的基本手法。 Some bas ic skills of reehand sketching should be mastered (1)握笔方法 the way of hold ing pencil 手握笔的位置要比用仪器绘图时髙些,以利运笔和观察目标。笔杆与纸面 45°-60°角,执笔稳而有力。 The pencil should be hold tightly the hold ing positi should be higher than drawing tools. The angle between the penholder and the pape is45°~60° (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 ashapes 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 45º~60º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 45º~60º. （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