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机械制造工艺学课程:工艺设计基础.ppt

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1、 integral turning tool、welded tool、clamped tool and rotation-able tool according to the structure. Classificationandcomparisonofturningtool: welded tool Advantage:simplestructure、compact;rigidity、shockresistance;easyto produceanduse. disadvantage:worsecapabilityofcutting、non-recycledtoolbar、longer s

2、etuptime. 1型直头、弯头外圆、内孔、宽刃 车刀 2型端面车刀、内孔车刀(盲孔 ) 3型90偏刀、端面车刀 4型直头外圆、端面车刀、内孔 车刀 5型直头外圆车刀、内孔车刀( 通孔) 6型内孔车刀(通孔) 1型燕尾槽刨刀 2型圆弧成形车刀 1型螺纹车刀 3型切断、车槽车刀 4型带棱边车槽刀 1型直头外圆车刀、内孔车刀 The tool groove of welding turning tool 1toolshank 2clamingdevice 3-toolblade 4-toolseat rotationable tool Advantage:longtoollife,higheff

3、iciency,helptospreadnewtechniqueand technologyandlowertoolcost. Attention:position(accurateornot),clamping(secureornot),chipflow (smoothornot),changeandsetup(easyornot) a)上式机 刀 b)切削力自 刀 c)性 式割刀 d) 立装式重切刀 e)削扁机螺 刀 f)性 式机刨刀 Clampedturningtool Clampedturningtool formingtool Advantage:recycledtoolbar,lo

4、ngtoollife Attention:position(accurateornot),clamping(secureornot),chipflow(smoothor not) Advantage:highefficiency,easytouse Attention:difficulttoproduce,highertoolcost 4.1.5 lathe fixtures or turning fixtures 1lathechuck 2lathedog 3-flange 4-centeringshaft 图35-4圆盘式车床夹具 1过渡盘2夹具体3分度盘4T形螺钉5、9螺母 6菱形销7定

5、位销8压板10对定销11平衡块 顶尖式心轴 1心轴2固定顶尖套3工件4活动顶尖套 5快换垫圈6螺母 本尺寸A0等于增环的基本尺寸之和减去减环的 基本尺寸之和,即 (2)各环极限尺寸之间的关系 封闭环的最大极限尺寸A0max等于增环的最大极限尺寸之和减去减 环的最小极限尺寸之和,即 5、尺寸链计算的基本公式 封闭环的最小极限尺寸A0min等于增环的最小极限尺寸 之和减去减环的最大极限尺寸之和,即 (3) 各环上、下偏差之间的关系 封闭环的上偏差ES(A0)等于增环的上偏差之和减去减 环的下偏差之和,即 封闭环的下偏差EI(A0)等于增环下偏差之和减去减环 的上偏差之和,即 (4)各环公差之间的关

6、系 封闭环的公差T(A0)等于各组成环的公差T(Ai)之和,即 极值法解算尺寸链的特点是:简便、可靠,但当封闭 环公差较小,组成环数目较多时,分摊到各组成环的公 差可能过小,从而造成加工困难,制造成本增加,在此 情况小,常采用概率法进行尺寸链的计算。 计算封闭环的竖式 口诀:增环上下偏差照抄; 减环上下偏差对调、反号 第八节 机械加工生产率和工艺方案比较 一 时间定额 单件时间 ,它由下述部分组成: (1)基本时间 (2)辅助时间 (3)布置工作地时间 (4)休息和生理需要时间 (5)准备与终结时间 二提高机械加工生产率的工艺措施 1缩减时间定额 (1)缩减基本时间 1)提高切削用量。 2)减

7、小或重合切削行程长度。 减小或重合切削长度 3)多件加工。 多件加工示意图 (2)缩减辅助时间 零件的生产成 本 第一类费用(工艺 成本) 与年产量有关的可变费用 V V材 V资 V护 V旧 V刀 V夹 与年产量无关的不变费用 C C调 C专机 C专夹 第二类费用非生产人员的开支 厂房折旧及维护费用 照明、取暧和通风费 运输费 三工艺方案比较 为分析和比较各种方案方便起见,将工艺成本分为 与年产量有关的可变费用V(元/件)和与年产量无关的 不变费用C(元/件)。 因此,有: S单V+C (1) 因不变费用C与年产量无关,所以一般常按全年 计算,以C年表示,上式写成: S单=V+C年/N零 (2

8、) 式中 N零零件的年产量。 全年产品的工艺成本为: S年=N零V+C年 (3) 从式(2)和式(3)看出,每个零件的工艺成本可用 双曲线表示,如图 (a),全年的产品工艺成本可用直 线表示,如图 (b)。 在图 (a)中,A为单件小批生产区,B为大批、大量生产区,A、B之间 为中批生产区。年产量越大,则成本越低,当N年时,则S单V,即年 产量很大时,S单的变化极小。在图 (b)中,不变费用C年为投资定值,无论 生产数量多少,其值不变,而S年却随产量N零的增加而增加,S年随N年成 正比变化。 见图3,两直线的相交处表明:当年产量为Nc时,则两种方案的全年工 艺成本相等,即S年l=S年2,说明两

9、种方案的经济性相同。Nc值可由下式求出 : 当年产量小于Nc时,采用第一种方案比较经济,全年工艺成本为S年l; 当年产量大于Nc时,采用第二种方案比较经济,全年工艺成本为S年2。 一. 1980考研英语翻译真题及答案Section VI Chinese-English Translation将下列句子译成英语:(本大题共20分,第1题2分,其余各题均3分)Section VI: Chinese-English Translation (20 points)1. 水一煮沸请立即把开关关掉。1. Please turn off the switch (switch off) as soon as

10、the water boils.2. 在八十年代,中国人民将以更大的步伐向前迈进。2. The Chinese people will forge ahead (march on, march onward, march forward) with greater strides in 1980s.3. 我们都同意李同志已作出的决定。3. We all agree to the decision comrade Li has made (made).4. 这个结果比我们预期的要好得多。4. The result is much (far) better than we expected.5.

11、在过去的三年中,在恢复我国国民经济方面做了大量的工作。5. During the past three years a lot (of work) has been done in the recovery (restoration) of our national economy (in recovering our national economy; in restoring our national economy).6. 我们把英语作为学习西方先进科学技术的一种工具。6. We use English as a tool in learning Western advanced sci

12、ence and technology.7. 没有党的领导,我国的社会主义现代化是不可能实现的。7. It is impossible to accomplish (carry out, fulfill, materialize) the socialist modernization of our country (our socialist modernization) without the leadership of the Party.Section VII English-Chinese Translation将下列短文译成汉语:(本大题30分)(文科各类专业译第1段,理、工、医、

13、农、体各类专业译第2段)Section VII: English-Chinese Translation (30 points)(1)The life of Albert Einstein is a model in many ways for both natural and political scientists.阿伯特爱因斯坦的一生在许多方面,无论是对自然科学家,还是政治科学家,都是一个范例。First of all, he always employed the scientific method of seeking truth from facts. He firmly beli

14、eved as he put it, that “there is nothing incomprehensible about the universe,”and through painstaking work, explained many of the phenomena thought to be “incomprehensible” in his day. Einstein was also never afraid to admit mistakes when facts proved his theories wrong.首先,他总是运用从事实中寻求真理的地。正如他所说的,他坚

15、信“关于宇宙没有东西是不可知的,”并经过艰苦的劳动,了许多在他那个时代被认为是“不可知”的种种现象。而且,当事实证明他的理论是错误的时候,爱因斯坦也从不害怕承认错误。Second, Einsteins contributions showed the great importance of theoretical work to scientific effort. Although he himself rarely worked in laboratories, the concepts he developed led to many of the scientific advances

16、 which have shaped modern technology.其次,爱因斯坦的贡献说明理论工作对科学成就的巨大的重要性。虽然他自己很少在实验室工作,他所发展的各种概念使科学取得了许多进展,从而形成了现代技术。Third, Einstein believed very deeply that scientists must have a moral and social consciousness. In this way, he provided inspiration for a whole generation of scientists who became active i

17、n the Communist movement.第三,爱因斯坦深信科学家必须具有道德和社会意识。这样,他鼓舞了整个一代的科学家,使他们积极参加共产主义运动。Einstein is often portrayed in bourgeois writings as a “genius”whose theories are so complicated that no one but a few best scientists can understand them. But he himself rejected the efforts to put him in a position far

18、above other people. He was well known for his humble manner and often stressed to interviewers that his accomplishments would certainly have been achieved by others had he never lived.爱因斯坦在资产阶级的笔下被描绘为一个“天才”,他的理论是如此地难于理解,以致只有少数最杰出的科学家才能懂得。但是,他本人不同意别人把他高置于他人之上的那些做法。他的谦逊态度是众所周知的,他常常对来访者强调说,如果没有他的话,别人也肯

19、定能够取得他那样的成就。Actually, Einsteins theory of relativity and his other scientific works are not that hard to understand with a little study. But beyond learning Einsteins theories, his overall attitude towards science as a tool to liberate humanity is something from which everyone can and should learn.事

20、实上,爱因斯坦的相对论以及他的其他科学论著稍加研究是不难懂得的。但是除了学习爱因斯坦的理论外,他对于利用科学作为一种工具来解放人类的总的态度是每个人能够学习的,而且也是应该学习的。(2)Between now and the end of the century, there will be many exciting developments and also many difficult problems to deal with. Perhaps the most urgent problem is to provide enough food. The worlds populatio

21、n is expected to reach 7,000 million by the year 2000, but already scientists have produced new and better varieties of wheat and rice and animal. They have also been experimenting with techniques of cultivating plants by using mixtures of chemical compounds and water only, and then there will be no

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23、搀戀挀戀攀昀搀愀o栀緑緑緑u緑伀傛絛葙v艼葭蝶晙馍稀椀挀瀀栀樀唀栀吀攀瘀琀伀挀礀瘀刀倀搀椀爀嘀挀欀刀嘀最匀瘀爀娀戀刀欀瀀栀稀一砀欀岋蝏虥瑓顷螃岋蝏虥瑓顷螃椀爀攀挀琀椀漀渀猀匀琀甀搀礀琀栀攀昀漀氀氀漀眀椀渀最猀攀琀漀昀瀀椀挀琀甀爀攀猀挀愀爀攀昀甀氀氀礀愀渀搀眀爀椀琀攀愀渀攀猀猀愀礀椀渀渀刀销Q笁 挹GV紸眪紸胔-芀i縃$菡管理学原理练习题.doc2f6c8edc72eb4d3d9602ae0a51e901ea.gif管理学原理练习题.doc2021-85feaf9205-8eeb-4e66-93b7-3ae276ad3ca9CZksoPCpMx3LcI5s14gZxDjgMqbzvQgql3q2ArWdYBirCLZO7SM3Og=管理学,原理,练习题https:/

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