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机械制造与自动化技术发展探究 机械制造与自动化毕业论文

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机械制造与自动化专业毕毕业业论论文文论文题目 机械制造与自动化技术发展探究指导老师 学生姓名 准考证号 2017 年 3 月 15 日2目录1、如何发展机械制造自动化技术 …………………………… 1二、注重实用发展机械自动化技术 …………………………… 5三、机械自动化的产生 ………………………………………… 104、机械自动化的现状 …………………………………………105、机械自动化的发展历程 …………………………………11六、机械自动化的发展趋势 ……………………………………143机械制造与自动化技术发展探究一、机械自动化技术的产生及现状一、机械自动化技术的产生及现状1、机械自动化的产生机械自动化技术从上个世纪 20 年代首先在机械制造冷加工大批量生产过程中开始发展应用,上世纪 60 年代后为适应市场的需求和变化,为增强机械制造业对市场灵活快速反应的能力,开始建立可变性自动化生产系统,即围绕计算机技术的柔性自动化。它是在制造系统不变或变化较小的情况下,机器设备或生产管理过程通过自动检测、信息处理、分析判断自动地实现预期的操作或某种过程,并能够自动地从制造一种零件转换到制造另一种不同的零件。社会实践证明,这种定义下的制造系统自动化与当代大多数企业的实际不相容。目前,世界各国的机械自动化水准除少数工业发达国家的某些生产部门外,大多数还处于操作阶段的自动化。我国也不例外,需要循序渐进,不断努力,创造条件,向自动化的高级理想阶段迈进。2、机械自动化技术的现状机械自动化技术从上个世纪 20 年代开始发展应用以来,已经得到了迅速的发展,特别是近年来计算机的高度集成化,开始采用了计算机集成制造系统,大大加快了机械自动化的发展,但我国仍处于初级操作阶段的自动化。目前,世界各国的机械自动化水准除少数工业发达国家的某些生产部门外,大多数还处于操作阶段的自动化。我国也不例外,我国的产业结构层次低。我国机械制造业目前4有 11.4 万个企业,发展很不平衡,有大量落后于现代水准的产业,大部分企业还比较落后,手工劳动占有相当的比重,我国能独立开发现代机械自动化技术的企业可以说没有;我国机械制造业企业中自动化装备少、水准低,不仅在数量上同世界先进国家有较大差距,而且在品种上、质量上、使用上,同世界先进水准也存在阶段性差距。实现我国机械自动化技术是一个长期的过程,不可能一蹴而就。需要循序渐进,不断努力,创造条件,向自动化的高级理想阶段迈进。当前,我国还处在社会主义初级阶段,经济、财力、生产力水准、国民素质等,与世界主要国家的差距是很大的;我国有丰富的劳动力资源,每年城镇新增就业人口达两千多万,且今后每年的就业人数还会增加。机械自动化最大限度地提高劳动生产率,劳动力的过剩和分工的转移就是一个现实问题。二、机械自动化的发展历程机械自动化技术从本世纪 20 年代首先在机械制造冷加工大批量生产过程中开始发展应用,60 年代后为适应市场的需求和变化,为增强机械制造业对市场灵活快速反应的能力,开始建立可变性自动化生产系统,即围绕计算机技术的柔性自动化。它是在制造系统不变或变化较小的情况下,机器设备或生产管理过程通过自动检测、信息处理、分析判断自动地实现预期的操作或某种过程,并能够自动地从制造一种零件转换到制造另一种不同的零件。70~80 年代国际上出现了开始采用计算机集成制造系统CIMS(Computer Integrated Manufacturing) ,柔性自动化生产模式5也有这种情况。初期犆犐犕犛以信息集成为重点,以较高的自动化程度为特征,但在实现过程中遇到了困难。鉴于实现计算机集成制造系统的全盘自动化所需的巨额投入(一个全盘自动化工厂耗资数百亿美元,柔性制造系统一般价格为 600~2500 万美元) ,所承担的巨大风险,加之技术上的难度与可靠性等问题,世界工业发达国家已开始“碰壁转产” ,转而注重信息集成的效果,追求低成本自动化LCA(Low Cost Automation)的企业组织结构和运行方式。目前,世界各国的机械自动化水准除少数工业发达国家的某些生产部门外,大多数还处于操作阶段的自动化。我国也不例外,需要循序渐进,不断努力,创造条件,向自动化的高级理想阶段迈进。实现我国机械自动化技术是一个长期的过程,不可能一蹴而就。我国机械制造业目前有11.4万个企业,发展很不平衡,有大量落后于现代水准的产业,大部分企业还比较落后,手工劳动占有相当的比重,我国能独立开发现代机械自动化技术的企业可以说没有;我国机械制造业企业中自动化装备少、水准低,不仅在数量上同世界先进国家有较大差距,而且在品种上、质量上、使用上,同世界先进水准也存在阶段性差距。三三、如何发展机械制造自动化技术、如何发展机械制造自动化技术首先先介绍机械自动化技术的应用与发展是机械制造业技术改造、技术进步的主要手段和技术发展的主要方向。就如何发展机械制造自动化技术从四方面进行阐述。 机械自动化, 主要指在机械制造业中应用自动化技术, 实现加6工对象的连续自动生产,实现优化有效的自动生产过程, 加快生产投入物的加工变换和流动速度。机械自动化技术的应用与发展, 是机械制造业技术改造、技术进步的主要手段和技术发展的主要方向。机械自动化的技术水准, 不仅影响整个机械制造业的发展, 而且对国民经济各部门的技术进步有很大的直接影响。 机械自动化的技术水准, 不仅影响整个机械制造业的发展, 而且对国民经济各部门的技术进步有很大的直接影响。如何发展我国的机械自动化技术, 应实事求是, 一切从我国的国情出发, 做好各项基础工作, 走中国的机械自动化技术发展之路。如何发展我国的机械自动化技术, 应实事求是, 一切从我国的具体国情出发, 做好各项基础工作, 走中国的机械自动化技术发展之路。 1. 结合生产实际, 注重实用发展机械自动化技术。先进制造技术的全部真谛在于应用。发展机械自动化技术, 应以企业的生 产和发展的实际需要及具体条件为导向。只有对合适的产品采用与之相适应的自动化方式进行生产, 才能收到良好的技术经 济效益和社会经济效益。我国发展机械自动化技术, 应结合实际, 注重实用, 即对国民经济产生实际效益。那种盲目搞自动化、 自动线的做法, 全年生产任务只需 1~2 个月就完成的低负荷 率生产也要搞的倾向应当纠正, 对国民经济不产生显著促进、效率低下的要缓搞。我们要的是效益, 而不单纯的是速度。 2. 发展投资少、见效快的低成本自动化技术。发展低成本7自动化技术, 潜力大, 前景广, 投资省, 见效快, 提高自动化程度, 可以收到事半功倍的经济效果, 适合我国现阶段的发展需要和国情。20 世纪 90 年代美国麻省理工学院提出的精节生产 LP ( Lean Production) 模式, 就是以最小的投入, 取得最大的产出的具体表现。借鉴国外发展机械制造业低成本自动化技术的经验是有益的。我国机械制造业各企业有大量的通用设备, 在发展现代机械自动化技术时, 应以原有的设备为主, 合理调整机床布局, 添加少量的数控设备, 引入 CAD/CAM 技术, 充分发挥计算机自动化管理的优势和人的创造性, 共同构成一个以人为中心, 以信息自动化为先导、树立自主的单元化生产系统, 为我国机械制造业自动化技术发展应用提供了一条投资少、见效快、效益高、符合我国国情的机械自动化技术发展应用新途径。通用机的局部自动化改装有重要意义。近期内我国对成本低、维修方便的通用机的需要量还是不会急剧下降的, 因为有广大的乡镇企业市场, 有小工厂、试验室、大型企业的工具车间等。 3. 结合中国国情, 发展现代机械自动化技术。实现机械自动化是一个由低级到高级、由简单到复杂、由不完善到完善的发展过程。当机械的操作采用自动控制器后, 生产方式才从机械化逐 步过渡到机械控制( 传统) 自动化、数字控制自动化、计算机控制自动化。只有建立了自动化工厂后, 生产过程才能全盘自动化,才能使生产率全面提高, 达到自动化的高级理想阶段。 中国实现机械自动化技术应是一个长期的过程, 不可能一蹴而就。当前, 中国机械制造8业同世界先进水准也存在阶段性差 距。在我国这种国情下, 普遍发展应用计算机集成制造系统的“全盘自动化”或“高度自动化”, 并不具备必要的基础技术、经验和投资能力。因此, 要不要普遍发展全盘自动化或高度自动化 CIMS 技术, 一定要慎重行事。而且全盘自动化或高度自动化的 CIMS 技术也并非我国机械制造业的当务之急, 只能列为机械制造自动化技术的主要发展方向。应该发展工艺成熟的大批量生产的自动化技术。我国现阶段, 在产品数量较大的同类产品连续流水作业的切削加工生产中, 自动化设备仍然是半自动机床、自动机床、组合机床及其组成的自动线、回转体零件加工自动线等。而在大批量的铸造、锻造、冲压、焊接、热处理和装配等生产中, 采用刚性自动化( 自动单机和自动线) 则是合理可行的, 能取得较好的经济效益; 对于品种稍多的成批生产, 应采用由快速重新调整的设备组成成组工段或流水线、可更换主轴箱组合机床自动线、短自动线和复合制造单元, 实现成组自动化; 而单件小批量生产, 应从推广成组技术入手, 适当发展采用数控机应酬或加工中心, 有针对性地建立一些揉性制造单元 FMC( Flexible Manu- facturing Cell) , 可取 得较好的经济效果。我国作为一个发展中国家, 考虑一切生产技术问题时的前提必须是适用。我国消化吸收国外柔性制造系统( Pseudo- FMS) , 是要确保必要的生产柔性的前提下, 优化人机界面, 不过分追求 自动化, 尽可能建立较为完善的信息系统, 充分发展计算机管理的效益。系统中先进的自动化装备和普通设备并存, 系统的某些环节允许人工9干预。这是一个典型的结合国情、实施适用先进方针的自动化技术解决方案。我国目前在消化呼吸、融会贯通国际上有用的自动化技术理论的基础上, 要努力做到从我国机械制造业的实际情况出发, 发展创新, 形成有国情特征的发展自动化技术理论和学说, 进行围绕计算机技术的柔性自动化技术的开发研究, 以适用为前提, 急需什么就解决什么, 取得实践经验再 推广应用。 4. 抓好基础, 注重配套发展机械自动化技术。发展应用机械自动化技术, 要扎扎实实地抓好自动化技术应用项目的基础工作和从实际出发的推广应用工作, 既要发展主机, 也要配套发展自动化元件及控制系统。可编程控制器、微处理机、各种传感器、新型刀具、控制系统及系统软件、电子计算机等将是今后机械自动化的主要技术基础。研究生产大量性能优良、自动化水准高的机电产品是发展应用机械自动化技术的关键。自动化生产时, 在系统的结构、质量( 重量) 、体积、刚性和耐性等方面对现代机械自 动化技术有着重要的影响, 机械技术应利用其它高新技术来更新, 实现与适应现代机械自动化技术的发展; 自动化生产时, 机械制造系统的自动控制、自动检测、伺服系统的操作等都少不了要应用微电子技术和自动控制理论; 自动化生产时, 信息的交换与处理、存取、运算、判断和决策等都少不了要应用计算机与信 息处理技术。 总之, 我国机械制造业发展应用自动化技术, 不但要起点高, 瞄准世界先进水准, 而且必须包括各种灵活的低成本、见效快的自动化技术, 坚持提高与普及相结合的方针, 我国的机械自动化技术发展10应用才能健康地走上高速度、高质量和高效益之路 。四、机械自动化的发展趋势机械自动化的发展趋势随着现代科学技术的进步和现代高效农业的不断发展,自动化控制技术在农业现代过程中不可替代的地位和作用越来越被人们所认识。农业自动化能够大大提高劳动生产率和增加劳动舒适性,而且随着经济的全球化,面临农产品开放进口和市场竞争的压力,现代业只有通过进一步提高生产率、降低生产成本和提高产品品质才能生存。从这些新的需求出发,农业生产着高效率和高精度的机械化、自动化方向发展是必然的选择。日前农业机械自动化大致有以下 3 类。一是已有农业机械及装置的部分自动化控制。这种自动化方式以提高已有农业机械及装置的作业与操作性能,提高作业效率和作业精度,减轻驾驶员的负担,节约资源等为目的。二是已有农业机械及装置的无人自动操作。这种自动化方式用在操作简单且容易实现无人运转,危险性大或是长时间重复单调过程的作业上。如用计算机程序或无线电遥控来操纵拖拉机及联合收割机、自动控制行驶、自动检测耕深、耕宽或作物行列数、自动完成作业,以及能使下煤机、自动化温室等固定装置自动完成作业的机械及装置。三是农业机器人。农业机器人是一种可由不同程序软件控制,以适应各种作业,能感觉并适应作物种类或环境变化,有检测(如视觉等)和演算等人工智能的新一代无人自动操作机械。11自动化技术特别是微电子自动控制技术在农机上的成功应用,是农业现代化的重要标志之一。根据我国实际国情,必须考虑该技术的成熟程度,即自动化技术本身的可靠性,必须考虑整机售价应适台我国农民当前的购买力,以及采用自动化技术的实用性和农民在操作使用维修保养时的方便性。现在农业生产自动化控制系统基本上是各种系统的集成,硬件上有传感器、传感器变换器接口、控制器、计算机网络、被控设备、总线等组成的。随着自动化信息技术和生物技术以及工程制造业的发展,智能控制技术的广泛应用,农业生产的精确控制必然是现代农业生产的发展方向。参考文献参考文献1.翁贻方,赵长德.现代控制技术基础.机械工业出版社,2003.42.冯辛安.机械制造装备设计.第二版.机械工业出版社,2009.13.龙飞.autoCAD2007 机械图形设计.电子科技大学出版社,2007.14.应锦春.现代设计方法.机械工业出版社,2000.45.全燕鸣.机械制造自动化.华南理工大学出版社, 2008.66.周骥平,林岗.机械制造自动化技术.机械工业出版社,2005.312An Analysis of Characteristics of American SlangAbstract: With the development of the society, slang is widely used by more and more people, especially in America, slang can be found favorable in the Americans’ eyes. Slang has gradually become popular among English speakers, since it appeared in English language in the 16th century. It is very popular in the English-speaking countries nowadays. Rich and colorful slang is an important component in English. However, it is difficult for people to understand. Therefore, it is necessary for us to study it. To have a glimpse into the nature of English slang is helpful to understand. This thesis expounds the characteristics of English slang. It concludes that slang is playing a more and more important role in the society of English-speaking. Key words: slang characteristics AmericanIntroduction Slang is a rather special parole. It is neither the word that beyond the regular role of grammatical usage, nor rural dialect. Although it is quite different from acrolect which used on the formal occasion, people quite like to use it in daily speech. That is to say, slang can be defined to common colloquial language, and slang is usually used as colloquial words and phrase. In other words, slang is Nonstandard-English. It is brimming with youth vigor. It is rather a spoken language than a written one. Unlike standard language, it does not from its own grammar rules. Mainly employed by sub-cultural groups, slang is highly colloquial, informal and essentially not respectable. Most of slang is more forceful, emotional or humorous forms than standard words. Slang is very informal and commonly used in speech. Between people from same social group or who work together, not considered suitable for formal contexts and often not in used for long. Slang has become an indispensable part of modern English. With the popularity of slang, we 13should know how to use slang and master its characteristics. This paper intends to make a tentative study on the characteristics of slang in America.1. Highly ColloquialSlang is highly colloquial, non-standard informal language. Being the quintessence of colloquial speech, slang is always related to convenience rather than to scientific laws, grammatical rules and philosophical ideas. It does not belong to the register of language used in formal records, epics, poetry, religious prose and other varieties of literature. As it originates from colloquial speech, so it flourishes best in colloquial speech.Slang, as a whole, is mainly employed in everyday, oral communications between friends and acquaintances or just within some special groups. On informal, private occasions, slang is the favorite means for oral communication. On some friendly occasion, when you talk in very formal way, maybe it will give others a feeling that you are talking with them in a commanding tone. Such feeling will broaden the distance between you and your friend. However, when you add some proper slang in your talking, you can have the talking atmosphere more friendlily.For example, a person wants to get his friend’s agreement eagerly. If the friend can understand the speakers’ feeling and his eagerness, he may say the following sentences: “I will drink that sentence.” It means “I definitely agree with you.” or “I will to accept advice.” Not only can the friend have his companion relaxed, but also express his agreeable attitude.2. Transience of slang’s lifeSlang is generally transient. Generally speaking, slang spreads very quickly yet it is unstable and temporary. That is to say, slang is the most unstable element of English and its life expectancy is generally short. Usually a popular slang of last year may no longer be heard this year or some slang once used by one generation may sound Greek to the next. The use of slang is closely related to the circumstances in which it is used. Once the circumstances changed, the slang relevant to it disappears too. However, not all the slang words die soon after its birth. Some linger on decade after decade, century after century, never becoming respectable or dying out. Take the word “booze” for example; it was used as slang in the Middle Ages, yet now it is still ranked among slang in some dictionaries. The word “dough” , a slang word for money, is just as hardly possible to become a standard word as it ever was, though no more respectable. Many old words have been cut off and a large amount of new words are added to slang. People’s attitudes toward 14slang vary from person to person. Some think that slang cannot be used on the formal occasion, for the illiterate people speak it only and the slang terms are so coarse. However, others hold the opposite idea. They think that slang play an important role in English language, because of its fresh, lifelike, humor and adequate expressions.3. Abundance of SynonymsSlang is abundant of synonyms. By the phrase “abundant of synonyms”, it refers to two phenomena. One is that slang almost exists side by side with another more general term for the same thing. For example, the slang phrase “as luck would have it” has been used by some speakers in the meaning “fortunately”. The difference between “as luck would have it” and “fortunately” can be stated only in reference to the people who use the word. Some say “As luck would have it, I found exactly what I was looking for”, others “Fortunately, I found exactly what I was looking for”, “As luck would have it “is slang and “fortunately” is not. Because “As luck would have it” is used by limited part of population, whereas, “fortunately” is used by everyone. It is found that slang can be regarded as words and phrases or particular meanings of words in common informal use, but generally it is not seen as standard in a language that used by specified expression or class. It is natural to refer it as the words that are commonly used, and can be understood by all people in America.4. Visualization of languageYou can express the same meaning with the standard language as well as slang. Nevertheless, slang maybe used to make your language more picturesque. It reveals something about the feeling or attitudes of the speaker. For example, a boss was very angry with his workers because they were dilatory in doing things. To emphasize his anger, he says, “Two hours off with the pay, why the hell are they dragging their tails. The slang “drag one’s tail” means, “Do something too slowly”. The speaker’s angry is displayed. Take another case for example “Thomas, a sad apple. Can he finish such special task?” In his sentence, “sad apple” means “a person who is always discouraged” The speaker expresses his deep suspicion with the aid of slang better than in the formal way.In a word, colloquialism is one of the characteristics of slang .It is spoken rather than written. Although more and more writers make use of American slang of contemporary teenagers, no matter how many slang words one can find in the novel, they are all used in the dialogues or 15conversation of its characters instead of in the narration or description. Therefore, they are still “spoken” though in writing.ConclusionIn the recent years, slang has been changing with each passing day and with the world’s development. Many old words have disappeared and lots of new words are added to slang. In a word, since slang’s appearance, it has been gaining respectfulness and plays important role in the social status. In the social life, even the words “hi” and “bye-bye” are slang words. Therefore, it is wrong if someone neglect slang’s study and slang translation. Slang has its special means and principles. Although slang is popular now, the people should selectively use it. If it is not special situation and has no context, we must not use it randomly. Slang can express different meaning and different information, but what it can perform actually depend on the language background. If we do not consider the occasion of talking, but only want to choose some slang to show out language character, maybe our talking will be thought as uncivil and improper. BibliographyDe Klerk, V. Hall. New Dictionary of American Slang[M]. New York: Harper and Row,1986Rodman. House Historical Dictionary of American Slang[M].New York: Cambridge, 1994Wentworth, Harold & Stuart Berg Flexner. Dictionary of American of Slang Second supplemented Edition [M]. New York: Thomas Y Crowell,1975Greenough, J.B, G. L. Kittredge, Words and Their Ways in English Speech[M] New York: Longman Group Ltd.,1985霍利.美国口语惯用例句集粹[M]. 北京:北京大学出版社,1996“空中英语”编委会.美国俚语精选[M]. 北京:机械工业出版社,2003牛津高阶英汉双解词典[Z].美国:牛津大学出版社,2002汪福祥.《英语口语精学本》[J]. 外文出版社 2004王爵鸾.英语俚语及其风格特征[J]. 外语学刊,1999(1)
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