电大CAD计算机绘图本实验1小抄参考.doc

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1、专业好文档天津广播电视大学工程高级技校实验报告课程名称计算机绘图实验题目椭圆轴测图姓名学号年级10秋专业名称机械设计制造及自动化层次本科实验时间2011924实验成绩实验教师签字一、 实验目的 通过实验掌握AutoCAD2000基础操作，同时掌握CAD绘图方法。二、 实验内容与要求在机械零件的轴测视图中，圆是以椭圆表示的，可分为三个方向（见图1），椭圆的长短轴之比为12.2：7，这是一个常数，必须记着！用这种比例的椭圆所绘轴测图最为真实，相当于三维效果。其余尺寸按实际尺寸绘制！图1三、实验过程、数据记录和有关计算主要绘图步骤如下：1、 先绘一10圆的椭圆（见图3），此后绘图中可缩放成不同直径的

2、圆的椭圆。很方便的技巧哟！此后绘图中，需要用到椭圆时，请复制第一步中的椭圆进行缩放和旋转。图32、 按制图规律，确定一条轴线（见图4）图43、 复制一椭圆到轴线的端点（见图5）图54、 先按内孔尺寸28放大椭圆（即放大2.8倍）（见图6）图65、 重复步骤3，复制一椭圆至轴线端点（见图7）JUrCAD/3D/Photoshop教程、资源网图76、 按外径尺寸68放大椭圆（即放大6.8倍）（见图8）JUrCAD/3D/Photoshop教程、资源网图87、 画零件的厚度10（=12.5-2.5）.只需将两椭圆沿轴线放向移动10（见图9）即可（先选择，再点击移动按钮，再输入距离数据），作外圆的切线

3、，如图，先画出椭圆的长轴，再向另一椭圆引切线。JUrCAD/3D/Photoshop教程、资源网图98、 剪掉多余的线条或不可视的线条（见图10）JUrCAD/3D/Photoshop教程、资源网9、 重复步骤3，复制椭圆至图示位置（偏移10之后的圆心），作零件左端的台阶，注：有可能是不可见的线，其实根据经验可以判断出是不可见的。不可见之线是不用绘出的。（见图11）JUrCAD/3D/Photoshop教程、资源网图1110、 按图尺寸42放大，并偏移2.5.注：如果左端台阶不可见，则不必画出。图示红线椭圆即零件左端的台阶，不可见而被删除。（见图12）JUrCAD/3D/Photoshop教程

4、、资源网图12If we dont do that it will go on and go on. We have to stop it; we need the courage to do it.His comments came hours after Fifa vice-president Jeffrey Webb - also in London for the FAs celebrations - said he wanted to meet Ivory Coast international Toure to discuss his complaint.CSKA general

5、director Roman Babaev says the matter has been exaggerated by the Ivorian and the British media.Blatter, 77, said: It has been decided by the Fifa congress that it is a nonsense for racism to be dealt with with fines. You can always find money from somebody to pay them.It is a nonsense to have match

6、es played without spectators because it is against the spirit of football and against the visiting team. It is all nonsense.We can do something better to fight racism and discrimination.This is one of the villains we have today in our game. But it is only with harsh sanctions that racism and discrim

7、ination can be washed out of football.The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifas anti-racism taskforce, is in London for the Football Associations 150th anniversary celebrations and will attend Citys Premier League match at Chelsea on Sunday.I am going to be at th

8、e match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport.For me its about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasopened disciplinary proceedings against CSKAfor the racist behaviour of their fans duringCitys 2-1 win.Michel Platin

9、i, president of European footballs governing body, has also ordered an immediate investigation into the referees actions.CSKA said they were surprised and disappointed by Toures complaint. In a statement the Russian side added: We found no racist insults from fans of CSKA.Baumgartner the disappointi

10、ng news: Mission aborted.The supersonic descent could happen as early as Sunda.The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule at

11、tached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and in

12、to the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.The balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth beco

13、mes the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is

14、 expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has

15、a stabilization parachute that can be deployed to slow him down. His team hopes its not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph

16、(277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.Even if everything goes as planned, it wont. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).cause there