问题 问答题 简答题

在设计普通冲裁模时,应怎样确定凸凹模间隙?

答案

参考答案:

设计模具时一定要选择一个合理的间隙,使冲裁件的断面质量好,尺寸精度高,模具寿命长,所需冲裁力小。但严格说来,并不存在一个同时满足所有理想要求的合理间隙。考虑到模具制造中的偏差及使用中的磨损,生产中通常是选择一个适当的范围作为合理间隙,只要模具间隙在这个范围内,就可以基本满足以上各项要求,冲出合格制件。考虑到模具在使用过程中的逐步磨损,设计和制造新模具时应采用最小合理间隙。确定合理间隙的方法主要有理论计算法和查表选取法两种。

判断题
阅读理解
阅读理解。
     Mr. Shaw wrote a lot of stories and people in the world knew him well. He didn't like the arrogant
(傲慢的) rich (富有的) men and often laughed at them. So people liked him very much.
     A lot of men hoped to know Mr. Shaw. One day a famous singer asked him to her party. When
Mr. Shaw came in, all the people stood up except a young man. The young man's father was one of
the richest men in England and he was studying in Paris (巴黎). He thought he knew much more than
anyone else in the room. He talked a lot and tried to show he was a know-all (自以为无所不知的人).
All the people listened to him and nobody would interrupt (打断) him. It made Mr. Shaw unhappy.
    "Please listen to me, my friend," Mr. Shaw had to stop him. "I think only we both know the things
in the world!"
     Hearing this, the young man was happy.
     "Maybe you know all," said Mr. Shaw. "But you don't know one thing!"
     "We are all tired of you," Mr. Shaw said with a smile. "Just I know it!"
     The young man's face turned red and didn't say anything until (直到) he left.
1. Mr. Shaw was ______.

[ ]

A. a great singer
B. a famous writer
C. a doctor
D. a famous teacher
2. All the people stood up when Mr. Shaw went in because            .

[ ]

A. they all respected (尊敬) him
B. they were all afraid of him
C. the singer made them do so
D. they wouldn't listen to the young man
3. The people at the party wouldn't interrupt the young man because            .

[ ]

A. he could tell them something interesting
B. he was studying in the capital of France
C. he was clever than them all
D. they didn't want to make him unhappy
4. At last the young man stopped talking because ______.

[ ]

A. nobody listened
B. he was very tired
C. he knew he was wrong
D. Mr. Shaw's words made him do so
5. Which of the following is not true?

[ ]

A. Mr. Shaw was tired of the young man.
B. The young man thought he learned a lot in Paris.
C. The young man said sorry to Mr. Shaw.
D. The young man knew that Mr. Shaw laughed at him.