问题 问答题 简答题

气密铆接应如何进行?

答案

参考答案:

1.将零件安装在构架上,检查零件与构架之间的贴合度,要求在100mm长度内,零件与构架之间的间隙不大于0.3mm。

2.定位、钻孔,用定位销或定位螺栓将零件固定在构架上。固定销之间的距离,应为80~120mm。固定顺序,可以从一端向另一端,也可以从中间推向两端。

3.气密铆接的铆钉孔必须钻直,不能歪斜和钉孔过大。

4.划窝深度必须准确,边划窝,边检查,允许铆钉凸出钉窝不大于0.1㎜,但不允许下凹。

5.拆下定位销或定位螺钉,分解零件与构架,除去铆钉孔中的毛刺和金属屑,用汽油清洗零件与构架结合的部位。

6.在构架上平铺一层密封胶垫,铺好后,用滚子滚平。

7.在零件的对缝处放臵直径为1.5~2mm的密封腻子条。

8.将零件重新安装在构架上,并使钉孔对准,用锥子锥出钉孔。锥子的直径通常比铆钉杆直径小0.2mm。用定位销或固定螺栓固定。

9.清除多余的腻子和密封胶布。

阅读理解

阅读理解。

     More and more people like bicycling and it is no surprise. It is fun ,healthy and good for the 

environment. Maybe that 't why there are l.4 billion bicycles  and only 400 million cars on roads 

worldwide today. Bikes can take you almost anywhere, and there is no oil cost!   

     Get on a bicycle and ride around your neigh b our hood. You may discover something new all 

around you. Stopping and getting off a bike is easier  than stopping and getting out of your car. You

 can bike to work and benefit(受益) from the enjoyable exercise without polluting the environment. 

You don't even have to ride all the way.    

     Folding (折叠) bikes work well for people who  ride the train. Just fold the bike and take it with you. 

You can do the same on an airplane. A folding bike can be packed in a suitcase.    

     You can also take a common bike with you  when you fly. But be sure to look for information by

 getting on airline websites.     

      Not all airlines are bicycle-friendly to travelers.     

      Health Benefits of Bicycling:   

      ●It helps to prevent heart diseases.   

      ●Bicycling helps to control your weight.

      A 15-minute bike ride to and from work three times a week burns off five kilos of fat in a year.   

      ●Bicycling can improve your mood(心情).         

      Exercise like bicycling has been shown to make people feel better, more relaxed and self-confident.  

      ●Bicycling is healthier than driving.

1. From the passage, we know that bicycling is be-coming very_____.  

A. surprising        

B. exciting

C. expensive        

D. popular

2. When you are riding your bicycle around your  neigh our hood, you may _____.   

A. pollute the environment around

B. find something you didn't notice

C. go everywhere and use a little oil

D. get off your bike and begin to work

3. If you travel with a folding bike, you can fold it and  _____.    

A. get out of the car    

B. take it onto a train

C. put it in your purse    

D. go on airline websites

4.One of the benefits from bicycling is that   

A. you can fold the bicycle

B. you will be friendly to others

C. you will be more relaxed

D. you may get fatter and fatter

5. Which is TRUE according to the passage?

A. Bicycling is enjoyable exercise for people.

B. Driving cars is healthier than riding bikes.

C. Riding a bike pollutes your neighbourhood.

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