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毕业论文外文翻译-冲压模具技术

毕业论文外文翻译-冲压模具技术
毕业论文外文翻译-冲压模具技术

前言

在目前激烈的市场竞争中,产品投入市场的迟早往往是成败的关键。模具是高质量、高效率的产品生产工具,模具开发周期占整个产品开发周期的主要部分。因此客户对模具开发周期要求越来越短,不少客户把模具的交货期放在第一位置,然后才是质量和价格。因此,如何在保证质量、控制成本的前提下加工模具是值得认真考虑的问题。模具加工工艺是一项先进的制造工艺,已成为重要发展方向,在航空航天、汽车、机械等各行业得到越来越广泛的应用。模具加工技术,可以提高制造业的综合效益和竞争力。研究和建立模具工艺数据库,为生产企业提供迫切需要的高速切削加工数据,对推广高速切削加工技术具有非常重要的意义。本文的主要目标就是构建一个冲压模具工艺过程,将模具制造企业在实际生产中结合刀具、工件、机床与企业自身的实际情况积累得高速切削加工实例、工艺参数和经验等数据有选择地存储到高速切削数据库中,不但可以节省大量的人力、物力、财力,而且可以指导高速加工生产实践,达到提高加工效率,降低刀具费用,获得更高的经济效益。

1.冲压的概念、特点及应用

冲压是利用安装在冲压设备(主要是压力机)上的模具对材料施加压力,使其产生分离或塑性变形,从而获得所需零件(俗称冲压或冲压件)的一种压力加工方法。冲压通常是在常温下对材料进行冷变形加工,且主要采用板料来加工成所需零件,所以也叫冷冲压或板料冲压。冲压是材料压力加工或塑性加工的主要方法之一,隶属于材料成型工程术。

冲压所使用的模具称为冲压模具,简称冲模。冲模是将材料(金属或非金属)批量加工成所需冲件的专用工具。冲模在冲压中至关重要,没有符合要求的冲模,批量冲压生产就难以进行;没有先进的冲模,先进的冲压工艺就无法实现。冲压工艺与模具、冲压设备和冲压材料构成冲压加工的三要素,只有它们相互结合才能得出冲压件。

与机械加工及塑性加工的其它方法相比,冲压加工无论在技术方面还是经济方面都具有许多独特的优点,主要表现如下;

(1) 冲压加工的生产效率高,且操作方便,易于实现机械化与自动化。这是

因为冲压是依靠冲模和冲压设备来完成加工,普通压力机的行程次数为每分钟可达几十次,高速压力要每分钟可达数百次甚至千次以上,而且每次冲压行程就可能得到一个冲件。

(2)冲压时由于模具保证了冲压件的尺寸与形状精度,且一般不破坏冲压件的表面质量,而模具的寿命一般较长,所以冲压的质量稳定,互换性好,具有“一模一样”的特征。

(3)冲压可加工出尺寸范围较大、形状较复杂的零件,如小到钟表的秒表,大到汽车纵梁、覆盖件等,加上冲压时材料的冷变形硬化效应,冲压的强度和刚度均较高。

(4)冲压一般没有切屑碎料生成,材料的消耗较少,且不需其它加热设备,因而是一种省料,节能的加工方法,冲压件的成本较低。

但是,冲压加工所使用的模具一般具有专用性,有时一个复杂零件需要数套模具才能加工成形,且模具制造的精度高,技术要求高,是技术密集形产品。所以,只有在冲压件生产批量较大的情况下,冲压加工的优点才能充分体现,从而获得较好的经济效益。

冲压加工在现代工业生产中,尤其是大批量生产中应用十分广泛。相当多的工业部门越来越多地采用冲压法加工产品零部件,如汽车、农机、仪器、仪表、电子、航空、航天、家电及轻工等行业。在这些工业部门中,冲压件所占的比重都相当的大,少则60%以上,多则90%以上。不少过去用锻造=铸造和切削加工方法制造的零件,现在大多数也被质量轻、刚度好的冲压件所代替。因此可以说,如果生产中不能采用冲压工艺,许多工业部门要提高生产效率和产品质量、降低生产成本、快速进行产品更新换代等都是难以实现的。

2.冲压的基本工序及模具

由于冲压加工的零件种类繁多,各类零件的形状、尺寸和精度要求又各不相同,因而生产中采用的冲压工艺方法也是多种多样的。概括起来,可分为分离工序和成形工序两大类;分离工序是指使坯料沿一定的轮廓线分离而获得一定形状、尺寸和断面质量的冲压(俗称冲裁件)的工序;成形工序是指使坯料在不破裂的条件下产生塑性变形而获得一定形状和尺寸的冲压件的工序。

上述两类工序,按基本变形方式不同又可分为冲裁、弯曲、拉深和成形四种基本工序,每种基本工序还包含有多种单一工序。

在实际生产中,当冲压件的生产批量较大、尺寸较少而公差要求较小时,若用分散的单一工序来冲压是不经济甚至难于达到要求。这时在工艺上多采用集中的方案,即把两种或两种以上的单一工序集中在一副模具内完成,称为组合的方法不同,又可将其分为复合-级进和复合-级进三种组合方式。

复合冲压——在压力机的一次工作行程中,在模具的同一工位上同时完成两种或两种以上不同单一工序的一种组合方法式。

级进冲压——在压力机上的一次工作行程中,按照一定的顺序在同一模具的不同工位上完面两种或两种以上不同单一工序的一种组合方式。

复合-级进——在一副冲模上包含复合和级进两种方式的组合工序。

冲模的结构类型也很多。通常按工序性质可分为冲裁模、弯曲模、拉深模和成形模等;按工序的组合方式可分为单工序模、复合模和级进模等。但不论何种类型的冲模,都可看成是由上模和下模两部分组成,上模被固定在压力机工作台或垫板上,是冲模的固定部分。工作时,坯料在下模面上通过定位零件定位,压力机滑块带动上模下压,在模具工作零件(即凸模、凹模)的作用下坯料便产生分离或塑性变形,从而获得所需形状与尺寸的冲件。上模回升时,模具的卸料与出件装置将冲件或废料从凸、凹模上卸下或推、顶出来,以便进行下一次冲压循环。

3.冲压技术的现状及发展方向

随着科学技术的不断进步和工业生产的迅速发展,许多新技术、新工艺、新设备、新材料不断涌现,因而促进了冲压技术的不断革新和发展。其主要表现和发展方向如下:

(1)冲压成形理论及冲压工艺方面冲压成形理论的研究是提高冲压技术的基础。目前,国内外对冲压成形理论的研究非常重视,在材料冲压性能研究、冲压成形过程应力应变分析、板料变形规律研究及坯料与模具之间的相互作用研究等方面均取得了较大的进展。特别是随着计算机技术的飞跃发展和塑性变形理论的进一步完善,近年来国内外已开始应用塑性成形过程的计算机模拟技术,即利用

有限元(FEM)等有值分析方法模拟金属的塑性成形过程,根据分析结果,设计人员可预测某一工艺方案成形的可行性及可能出现的质量问题,并通过在计算机上选择修改相关参数,可实现工艺及模具的优化设计。这样既节省了昂贵的试模费用,也缩短了制模具周期。

研究推广能提高生产率及产品质量、降低成本和扩大冲压工艺应用范围的各种压新工艺,也是冲压技术的发展方向之一。目前,国内外相继涌现出精密冲压工艺、软模成形工艺、高能高速成形工艺及无模多点成形工艺等精密、高效、经济的冲压新工艺。其中,精密冲裁是提高冲裁件质量的有效方法,它扩大了冲压加工范围,目前精密冲裁加工零件的厚度可达25mm,精度可达IT16~17级;用液体、橡胶、聚氨酯等作柔性凸模或凹模的软模成形工艺,能加工出用普通加工方法难以加工的材料和复杂形状的零件,在特定生产条件下具有明显的经济效果;采用爆炸等高能效成形方法对于加工各种尺寸在、形状复杂、批量小、强度高和精度要求较高的板料零件,具有很重要的实用意义;利用金属材料的超塑性进行超塑成形,可以用一次成形代替多道普通的冲压成形工序,这对于加工形状复杂和大型板料零件具有突出的优越性;无模多点成形工序是用高度可调的凸模群体代替传统模具进行板料曲面成形的一种先进技术,我国已自主设计制造了具有国际领先水平的无模多点成形设备,解决了多点压机成形法,从而可随意改变变形路径与受力状态,提高了材料的成形极限,同时利用反复成形技术可消除材料内残余应力,实现无回弹成形。无模多点成形系统以CAD/CAM/CAE技术为主要手段,能快速经济地实现三维曲面的自动化成形。

(2)冲模是实现冲压生产的基本条件.在冲模的设计制造上,目前正朝着以下两方面发展:一方面,为了适应高速、自动、精密、安全等大批量现代生产的需要,冲模正向高效率、高精度、高寿命及多工位、多功能方向发展,与此相比适应的新型模具材料及其热处理技术,各种高效、精密、数控自动化的模具加工机床和检测设备以及模具CAD/CAM技术也在迅速发展;另一方面,为了适应产品更新换代和试制或小批量生产的需要,锌基合金冲模、聚氨酯橡胶冲模、薄板冲模、钢带冲模、组合冲模等各种简易冲模及其制造技术也得到了迅速发展。

精密、高效的多工位及多功能级进模和大型复杂的汽车覆盖件冲模代表了现代冲模的技术水平。目前,50个工位以上的级进模进距精度可达到2微米,多

功能级进模不仅可以完成冲压全过程,还可完成焊接、装配等工序。我国已能自行设计制造出达到国际水平的精度达2~5微米,进距精度2~3微米,总寿命达1亿次。我国主要汽车模具企业,已能生产成套轿车覆盖件模具,在设计制造方法、手段方面已基本达到了国际水平,但在制造方法手段方面已基本达到了国际水平,模具结构、功能方面也接近国际水平,但在制造质量、精度、制造周期和成本方面与国外相比还存在一定差距。

4.冲压标准化及专业化生产方面

模具的标准化及专业化生产,已得到模具行业和广泛重视。因为冲模属单件小批量生产,冲模零件既具的一定的复杂性和精密性,又具有一定的结构典型性。因此,只有实现了冲模的标准化,才能使冲模和冲模零件的生产实现专业化、商品化,从而降低模具的成本,提高模具的质量和缩短制造周期。目前,国外先进工业国家模具标准化生产程度已达70%~80%,模具厂只需设计制造工作零件,大部分模具零件均从标准件厂购买,使生产率大幅度提高。模具制造厂专业化程度越不定期越高,分工越来越细,如目前有模架厂、顶杆厂、热处理厂等,甚至某些模具厂仅专业化制造某类产品的冲裁模或弯曲模,这样更有利于制造水平的提高和制造周期的缩短。我国冲模标准化与专业化生产近年来也有较大发展,除反映在标准件专业化生产厂家有较多增加外,标准件品种也有扩展,精度亦有提高。但总体情况还满足不了模具工业发展的要求,主要体现在标准化程度还不高(一般在40%以下),标准件的品种和规格较少,大多数标准件厂家未形成规模化生产,标准件质量也还存在较多问题。另外,标准件生产的销售、供货、服务等都还有待于进一步提高。

Introduction

In the current fierce market competition, the product to market sooner or later is often the key to the success or failure. Mould is a product of high quality, high efficiency production tool, mold development cycle of the main part of the product development cycle. So the customer requirements for mold development cycle shorter, many customers put the mould delivery date in the first place, and then the quality and price. Therefore, how to ensure the quality, control the cost under the premise of processing mould is a problem worthy of serious consideration. Mold processing technology is an advanced manufacturing technology, has become an important development direction, in the aerospace, automotive, machinery and other industries widely used. Mold processing technology, can improve the comprehensive benefit and competitiveness of manufacturing industry. Research and establish mold process database, provide production enterprises urgently need to high speed cutting processing data, to the promotion of high-speed machining technology has very important significance. This article's main goal is to build a stamping die processing, mold manufacturing enterprises in the actual production combined cutting tool, workpiece and machine tool with the actual situation of enterprise itself accumulate to high speed cutting processing instance, process parameters and experience of high speed cutting database selectively to store data, not only can save a lot of manpower and material resources, financial resources, but also can guide the high speed machining production practice, to improve processing efficiency, reduce the tooling cost and obtain higher economic benefits.

1.Stamping the concept, characteristics and applications

Stamping is using stamping equipment installed in the (mainly) on the mold to pressure on the material, make its produce a separation or plastic deformation, to obtain the required parts (commonly known as stamping or stamping parts) of a pressure processing method. Stamping is usually at room temperature to cold

deformation processing of materials, and mainly adopts sheet metal to processed into the required parts, so also called cold stamping or sheet metal stamping. Stamping is material pressure processing or one of the main methods of plastic processing, belonging to material molding engineering technique.

Used by stamping mold known as the stamping die, die for short. Die is the material (metal or non-metallic) processing into salt pieces of special tools required. Is of vital importance to the die in stamping, did not conform to the requirements of punching die, stamping production batch is difficult; No advanced punching die, stamping process of advanced cannot achieve. Stamping process and die, stamping equipment and materials to form the three elements of stamping processing, can only draw stamping them together.

Compared with other methods of mechanical processing and plastic processing, stamping processing both in technology and economy has many unique advantages. Main show is as follows:

(1) the stamping process of high production efficiency, and easy to operate, easy to realize mechanization and automation. This is because the stamping is depend on the die and stamping equipment to complete the processing, ordinary press stroke times per minute can reach dozens of times, high pressure to can reach more than hundreds of times or even one thousand times per minute, and every time stamping stroke can get one piece.

(2) when the mold to ensure the stamping precision stamping parts of the size and shape, and generally does not destroy the surface of the stamping parts quality, and the life of the mould are long, so the stamping quality is stable, good compatibility, has the characteristics of "the same".

(3) stamping machining size range is larger, more complex shape parts, such as small to watch the stopwatch, big to auto longeron, covering parts, etc., and stamping material hardening effect of cold deformation, the strength and stiffness of stamping was high.

(4) stamping generally no chip broken material, material consumption is less, and do not need other heating equipment, it is a kind of material, machining method

of energy saving, stamping parts of the cost is low.

However, stamping process used by mould generally has specificity, sometimes need several sets of mould to a complex parts processing and forming, and mold manufacturing of high precision, high technical requirements, is the technology intensive product. Therefore, only under the condition of the stamping production batch is bigger, can fully embody the advantages of stamping processing, in order to gain good economic benefits.

Stamping processing in the modern industrial production, especially they are widely used in the mass production. Quite a number of industrial sector increasingly by stamping parts processing products, such as automobile, agricultural machinery, instruments, meters, electronic, aviation, aerospace, electrical appliances, light industry, etc. In the industrial sector, the ratio of stamping parts are quite big, less is more than 60%, more than 90% above. A lot in the past with forging = manufacturing parts, casting and machining method now most also replaced by light weight, good stiffness of stamping. Therefore, if you don't dare use stamping process in production, many industrial department to improve production efficiency and product quality, reduce production cost and rapid product update is difficult to achieve.

2.The basic process of stamping and mold

Because there are many different kinds of stamping parts processing, all kinds of spare parts of shape, size, and the requirement of accuracy but also each are not identical, and therefore used in the production of stamping process methods are varied. In summary, can be divided into two categories, separation process and forming process; The outline of electrodes in the separation process is directed along a certain line of separation and get a certain shape, size and cross section quality of stamping process (commonly known as blanking pieces); Electrodes in the forming process is

directed under the condition of not burst produce plastic deformation and to obtain a certain shape and size of the stamping process.

The above two kinds of process, according to the basic deformation in different ways and can be divided into cutting, bending, deep drawing and forming four basic processes, each of the basic process also contains a variety of single process.

In actual production, when the stamping production batch with fewer larger, size and tolerance requirement is small, if use dispersed to stamping is not the economy or even a single process is difficult to meet the requirements. Then use concentrated more on craft scheme, where two or more single process focused on the finish, a pair of mold is called combination method is different, and it can be divided into compound - level into and composite - level into three combinations.

Compound stamping - in a press work trip, in the mold of the same station at the same time to complete two or more than two different single process of a kind of combination method.

Progressive stamping - in a pressure on a working trip, in a certain order in the same mould of different location on the surface of two or more than two different single process of a kind of combination.

Compound - progressive -- on a pair of die with composite and the level into the combination of the two ways of working procedure.

The type of punching die structure is very much also. Usually according to the nature of the process can be divided into the blanking die, bending die, drawing die and forming mould, etc.; According to the process of combination can be divided into progressive die die, compound die and the single process, etc. But no matter what type of punching die, can be regarded as the upper die and lower die of two parts, the upper die was fixed in press a table or on the plate, is a fixed part of the die. Work, billet next mold surface parts with location positioning, press on the slider to drive mould press, in the mold working parts (punch and die) under the action of billet and produce a separation or plastic deformation, so as to obtain the required shape and

size of the stamping. Recovery of upper die, mold unloading and a device to salt pieces or waste discharged from the convex and concave die, or push, top out, stamping for the next cycle.

3.Stamping technology present situation and developing direction

Along with the advance of science and technology and the rapid development of industrial production, many new technologies, new processes, new equipment, new materials constantly emerging, and thus to promote the continuous innovation and development of stamping technology. The main performance and the development direction is as follows:

(1). Stamping theory and stamping process in stamping theory research is to improve the stamping technology. At present, the research on theory of stamping very seriously, in material performance research, stamping law of stress and strain analysis, the deformation of sheet metal forming process research and the interaction between billet and mold and so on have made greater progress. Especially with the rapid development of computer technology and the theory of plastic deformation of further perfect, has been used at home and abroad in recent years, the plastic forming process of computer simulation technology, the use of finite element method (FEM) and value analysis method to simulate the metal plastic forming process, according to the analysis results, designers can predict the feasibility of a forming process and the possible quality problems, and through the revision related parameters on the computer, which can realize the optimization of technology and die design. This saves expensive test, also shortened the mould cycle.

Research promotion can increase productivity and product quality, reduce costs and expand the scope of application of all kinds of new technology, stamping process is also one of the development direction of stamping technology. At present, both at home and abroad have sprung up precision stamping process, the soft mould forming process, high energy mould multi-point forming technology such as high speed forming process and precision stamping process for a new, efficient and economic.

Among them, the fine blanking is one of the effective methods to improve the quality of blanking pieces, it expanded the stamping processing range, at present the thickness of fine blanking processing parts can be up to 25 mm, precision can reach IT16 grade ~ 17; Using liquid, rubber, polyurethane, etc as the soft mode of flexible punch or die forming technology, can work out with ordinary processing methods are difficult to machining materials and complex shape parts, under the condition of specific production has obvious economic effect; Explosion energy efficient, such as forming methods for processing complicated in all sizes, shapes, small bulk, high strength and high accuracy of sheet metal parts, has very important practical significance; Using super molding superplasticity of metal materials, can be used instead of a forming multichannel common stamping process, for processing complicated shape and large sheet metal parts has prominent advantages; No mold multi-point forming process is highly adjustable punch group instead of traditional moulds for sheet metal surface forming a kind of advanced technology, our country has independent design and manufacture of the international leading level of

multi-point forming equipment, to solve the multi-point press forming method, which can change the deformation path and stress state, improves the forming limit of material, at the same time use repeatedly forming technology can eliminate the residual stress in the material, forming springback is realized. No mold multi-point forming (MPF) system with CAD/CAM/CAE technology as main means, rapid economy to realize the automation of 3 d surface shape.

(2) die is the realization of the basic conditions of stamping production. In die design and manufacture, at present is developing towards the following two aspects: on the one hand, in order to adapt to high speed, automatic, precise, security, and so on large quantities of the need of modern production, punching die and life expectancy is high efficiency, high precision, high transfer, multi-function direction, by contrast to adapt to the new die material and heat treatment technology, all kinds of high efficiency, precision, CNC automatic mould machine and testing equipment and mould CAD/CAM technology is in rapid development; Upgrading, on the other hand,

in order to adapt to the product and the need of trial production and small batch production, zinc base alloy die, polyurethane rubber punching die, die plate and steel belt punch, such as the simple combination die die and manufacturing technology has been developing rapidly.

Precision, high efficiency of multistep progressive die and the multi-function and large complex automotive covering parts die represents the modern technology of progressive die. At present, more than 50 location precision progressive die into the distance can be up to 2 microns, multifunctional and can not only complete the whole stamping process of progressive die, but also can complete the welding, assembly process, etc. In China has been able to design and produce precision has reached the international level of 2 ~ 5 microns, into from 2 ~ 3 micron precision, total life over 100 million times. Major automobile mould enterprises in our country, has been able to production of complete sets of car covering mould, in terms of design and manufacturing methods and means has basically reached the international level, but in terms of manufacturing methods has basically reached the international level, mould structure and function was close to the international level, but in manufacturing quality, accuracy, manufacturing cycle and cost when there is a certain gap compared with abroad.

4.Stamping standardization and specialization of production

Mould standardization and specialization of production, has been widely and mould industry. Because die sheet small batch production, the die parts both have certain complexity and precision, and has certain representativeness structure. Only to implement the standardization of die, therefore, can make the die and punch parts production implementation of specialization and commercialization, so as to reduce the cost of the mold, improve the mould quality and shorten the manufacturing cycle. At present, foreign advanced industrial countries mould standardization production degree has reached 70% ~ 80%, and the working parts of the mold factory need to design and manufacture, most of the mold parts are purchased from standard parts

factory, make the productivity increased significantly. Mold factory specialized degree is not regular higher and higher, division of labor is more and more thin, such as there are mould frame works, plunger, plant, heat treatment, etc., and even some mold factory specialized manufacture of certain products only blanking die or bending die, so that more conducive to the improvement of manufacturing and shorten manufacturing cycle. Die standardization and specialization production in our country also has great development in recent years, in addition to reflect outside the standard parts professional manufacturers have more increase, standard varieties have extended, precision is also improved. Overall situation but also to meet the demands of the development of mould industry is mainly manifested in the standardization degree is not high (generally below 40%), less standard varieties and specifications, most standard parts manufacturers did not form large-scale production, standard quality and have more problems. In addition, sales of standard parts production, supply, service and so on all has yet to be further improved.

献中有特殊的意思,这时就可以通过CNKI的“翻译助手”来查询相关单词的意思,由于CNKI的单词意思都是来源与大量的文献,所以它的吻合率很高。

另外,在翻译过程中最好以“段落”或者“长句”作为翻译的基本单位,这样才不会造成“只见树木,不见森林”的误导。

四大工具:

1、Google翻译:https://www.doczj.com/doc/9e19043347.html,/language_tools

google,众所周知,谷歌里面的英文文献和资料还算是比较详实的。我利用它是这样的。一方面可以用它查询英文论文,当然这方面的帖子很多,大家可以搜索,在此不赘述。回到我自己说的翻译上来。下面给大家举个例子来说明如何用吧

比如说“电磁感应透明效应”这个词汇你不知道他怎么翻译,

首先你可以在CNKI里查中文的,根据它们的关键词中英文对照来做,一般比较准确。

在此主要是说在google里怎么知道这个翻译意思。大家应该都有词典吧,按中国人的办法,把一个一个词分着查出来,敲到google 里,你的这种翻译一般不太准,当然你需要验证是否准确了,这下看着吧,把你的那支离破碎的翻译在google里搜索,你能看到许多相关的文献或资料,大家都不是笨蛋,看看,也就能找到最精确的翻译了,纯西式的!我就是这么用的。

2、CNKI翻译:https://www.doczj.com/doc/9e19043347.html,

CNKI翻译助手,这个网站不需要介绍太多,可能有些人也知道的。主要说说它的有点,你进去看看就能发现:搜索的肯定是专业词汇,而且它翻译结果下面有文章与之对应(因为它是CNKI检索提供的,它的翻译是从文献里抽出来的),很实用的一个网站。估计别的写文章的人不是傻子吧,它们的东西我们可以直接拿来用,当然省事

了。网址告诉大家,有兴趣的进去看看,你们就会发现其乐无穷!还是很值得用的。https://www.doczj.com/doc/9e19043347.html,

3、网路版金山词霸(不到1M):

https://www.doczj.com/doc/9e19043347.html,/6946901637944806

4、有道在线翻译:https://www.doczj.com/doc/9e19043347.html,/?keyfrom=fanyi.logo

翻译时的速度:

这里我谈的是电子版和打印版的翻译速度,按个人翻译速度看,打印版的快些,因为看电子版本一是费眼睛,二是如果我们用电脑,可能还经常时不时玩点游戏,或者整点别的,导致最终SPPEED变慢,再之电脑上一些词典(金山词霸等)在专业翻译方面也不是特别好,所以翻译效果不佳。在此本人建议大家购买清华大学编写的好像是国防工业出版社的那本《英汉科学技术词典》,基本上挺好用。再加上网站如:google CNKI翻译助手,这样我们的翻译速度会提高不少。

具体翻译时的一些技巧(主要是写论文和看论文方面)

大家大概都应预先清楚明白自己专业方向的国内牛人,在这里我强烈建议大家仔细看完这些头上长角的人物的中英文文章,这对你在专业方向的英文和中文互译水平提高有很大帮助。

我们大家最蹩脚的实质上是写英文论文,而非看英文论文,但话说回来我们最终提高还是要从下大工夫看英文论文开始。提到会看,我想它是有窍门的,个人总结如下:

1、把不同方面的论文分夹存放,在看论文时,对论文必须做到看完后完全明白(你重视的论文);懂得其某部分讲了什么(你需要参考的部分论文),在看明白这些论文的情况下,我们大家还得紧接着做的工作就是把论文中你觉得非常巧妙的表达写下来,或者是你论文或许能用到的表达摘记成本。这个本将是你以后的财富。你写论文

(完整版)冲压类外文翻译、中英文翻译冲压模具设计

附件1:外文资料翻译译文 冲压模具设计 对于汽车行业与电子行业,各种各样的板料零件都是有各种不同的成型工艺所生产出来的,这些均可以列入一般种类“板料成形”的范畴。板料成形(也称为冲压或压力成形)经常在厂区面积非常大的公司中进行。 如果自己没有去这些大公司访问,没有站在巨大的机器旁,没有感受到地面的震颤,没有看巨大型的机器人的手臂吧零件从一个机器移动到另一个机器,那么厂区的范围与价值真是难以想象的。当然,一盘录像带或一部电视专题片不能反映出汽车冲压流水线的宏大规模。站在这样的流水线旁观看的另一个因素是观看大量的汽车板类零件被进行不同类型的板料成形加工。落料是简单的剪切完成的,然后进行不同类型的加工,诸如:弯曲、拉深、拉延、切断、剪切等,每一种情况均要求特殊的、专门的模具。 而且还有大量后续的加工工艺,在每一种情况下,均可以通过诸如拉深、拉延与弯曲等工艺不同的成形方法得到所希望的得到的形状。根据板料平面的各种各样的受应力状态的小板单元体所可以考虑到的变形情形描述三种成形,原理图1描述的是一个简单的从圆坯料拉深成一个圆柱水杯的成形过程。 图1 板料成形一个简单的水杯

拉深是从凸缘型坯料考虑的,即通过模具上冲头的向下作用使材料被水平拉深。一个凸缘板料上的单元体在半径方向上被限定,而板厚保持几乎不变。板料成形的原理如图2所示。 拉延通常是用来描述在板料平面上的两个互相垂直的方向被拉长的板料的单元体的变形原理的术语。拉延的一种特殊形式,可以在大多数成形加工中遇到,即平面张力拉延。在这种情况下,一个板料的单元体仅在一个方向上进行拉延,在拉长的方向上宽度没有发生变化,但是在厚度上有明确的变化,即变薄。 图2 板料成形原理 弯曲时当板料经过冲模,即冲头半径加工成形时所观察到的变形原理,因此在定向的方向上受到改变,这种变形式一个平面张力拉长与收缩的典型实例。 在一个压力机冲程中用于在一块板料上冲出一个或多个孔的一个完整的冲压模具可以归类即制造商标准化为一个单工序冲孔模具,如图3所示。

毕业论文外文翻译模版

吉林化工学院理学院 毕业论文外文翻译English Title(Times New Roman ,三号) 学生学号:08810219 学生姓名:袁庚文 专业班级:信息与计算科学0802 指导教师:赵瑛 职称副教授 起止日期:2012.2.27~2012.3.14 吉林化工学院 Jilin Institute of Chemical Technology

1 外文翻译的基本内容 应选择与本课题密切相关的外文文献(学术期刊网上的),译成中文,与原文装订在一起并独立成册。在毕业答辩前,同论文一起上交。译文字数不应少于3000个汉字。 2 书写规范 2.1 外文翻译的正文格式 正文版心设置为:上边距:3.5厘米,下边距:2.5厘米,左边距:3.5厘米,右边距:2厘米,页眉:2.5厘米,页脚:2厘米。 中文部分正文选用模板中的样式所定义的“正文”,每段落首行缩进2字;或者手动设置成每段落首行缩进2字,字体:宋体,字号:小四,行距:多倍行距1.3,间距:前段、后段均为0行。 这部分工作模板中已经自动设置为缺省值。 2.2标题格式 特别注意:各级标题的具体形式可参照外文原文确定。 1.第一级标题(如:第1章绪论)选用模板中的样式所定义的“标题1”,居左;或者手动设置成字体:黑体,居左,字号:三号,1.5倍行距,段后11磅,段前为11磅。 2.第二级标题(如:1.2 摘要与关键词)选用模板中的样式所定义的“标题2”,居左;或者手动设置成字体:黑体,居左,字号:四号,1.5倍行距,段后为0,段前0.5行。 3.第三级标题(如:1.2.1 摘要)选用模板中的样式所定义的“标题3”,居左;或者手动设置成字体:黑体,居左,字号:小四,1.5倍行距,段后为0,段前0.5行。 标题和后面文字之间空一格(半角)。 3 图表及公式等的格式说明 图表、公式、参考文献等的格式详见《吉林化工学院本科学生毕业设计说明书(论文)撰写规范及标准模版》中相关的说明。

毕业论文英文参考文献与译文

Inventory management Inventory Control On the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion. The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility. Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored: First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments . Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field of

概率论毕业论文外文翻译

Statistical hypothesis testing Adriana Albu,Loredana Ungureanu Politehnica University Timisoara,adrianaa@aut.utt.ro Politehnica University Timisoara,loredanau@aut.utt.ro Abstract In this article,we present a Bayesian statistical hypothesis testing inspection, testing theory and the process Mentioned hypothesis testing in the real world and the importance of, and successful test of the Notes. Key words Bayesian hypothesis testing; Bayesian inference;Test of significance Introduction A statistical hypothesis test is a method of making decisions using data, whether from a controlled experiment or an observational study (not controlled). In statistics, a result is called statistically significant if it is unlikely to have occurred by chance alone, according to a pre-determined threshold probability, the significance level. The phrase "test of significance" was coined by Ronald Fisher: "Critical tests of this kind may be called tests of significance, and when such tests are available we may discover whether a second sample is or is not significantly different from the first."[1] Hypothesis testing is sometimes called confirmatory data analysis, in contrast to exploratory data analysis. In frequency probability,these decisions are almost always made using null-hypothesis tests. These are tests that answer the question Assuming that the null hypothesis is true, what is the probability of observing a value for the test statistic that is at [] least as extreme as the value that was actually observed?) 2 More formally, they represent answers to the question, posed before undertaking an experiment,of what outcomes of the experiment would lead to rejection of the null hypothesis for a pre-specified probability of an incorrect rejection. One use of hypothesis testing is deciding whether experimental results contain enough information to cast doubt on conventional wisdom. Statistical hypothesis testing is a key technique of frequentist statistical inference. The Bayesian approach to hypothesis testing is to base rejection of the hypothesis on the posterior probability.[3][4]Other approaches to reaching a decision based on data are available via decision theory and optimal decisions. The critical region of a hypothesis test is the set of all outcomes which cause the null hypothesis to be rejected in favor of the alternative hypothesis. The critical region is usually denoted by the letter C. One-sample tests are appropriate when a sample is being compared to the population from a hypothesis. The population characteristics are known from theory or are calculated from the population.

冲压模具文献综述

文献综述1 引言冲压模具是冲压生产必不可少的工艺装备,是技术密集型产品。冲 压件的质量、生产效率以及生产成本等,与模具设计和制造有直接关系。模具设计与制造技术水平的高低,是衡量一个国家产品制造水平高低的重要标志之一,在很大程度上决定着产品的质量、效益和新产品的开发能力。2005 年—2008 年,我国冲压模具产品均出口较大幅度的增长。2009 年在全球高压锅炉管市场总需求量下降的情况下,国际采购商通过国内某网站采购冲压模具的数量仍逆势上扬。我国冲压模具的国际竞争力正在不断提升。根据我国海关统计资料显示,2005 年—2008 年,我国冲压模具产品均出口较大幅度的增长。2008 年,即使遭受全球金融危机,我们冲压模具出口金额达4.11 亿美元,比2007 年的3.26 亿美元增长了26 。另外,2009 年在全球高压锅炉管市场总需求量下降的情况下,国际采购商通过国内某网站采购冲压模具的数量仍逆势上扬。从全年采购情况来看,总体趋于上涨的趋势。其中,2009 年下半年回暖明显,国际采购商借此网站采购频次约616 频次,比上半年的288 频次增长了114%。虽然近年来我国模具行业发展迅速,但是离国内的需要和国际水平还有很大的差距。差距较大主要表现在:(1 )标准化 程度低。(2)模具制造精度低、周期长。解决这些问题主要体现在模具设计上,故改善模具设计的水平成为拉近差距的关键性问题。若要很好的设计出一副冲压模具,就必须去了解冲压模具的历史、现状以及发展趋势。2 主体2.1 冲压模具的发展历史我国考古发现,早在2000 多年前,我国已有冲压模具被用于制造铜器,证明了中国古代冲压成型和冲压模具方面的成就就在世界领先。1953 年,长春第一汽车制造厂在中国首次建立了冲模车间,该厂于1958 年开始制造汽车覆盖件模具。我国于20 世纪60 年代开始生产精冲模具。在走过了温长的发展道路之后,目前我国已形成了300 多亿元(未包括港、澳、台 的统计数字,下同)各类冲压模具的生产能力。浙江宁波和黄岩地区的“模具之乡”;广东一些大集团公司和迅速崛起的乡镇企业,科龙、美的、康佳等集团纷纷建立了自己的模具

冲压模具技术外文翻译(含外文文献)

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毕业论文(设计)外文翻译 题目:中国上市公司偏好股权融资:非制度性因素 系部名称:经济管理系专业班级:会计082班 学生姓名:任民学号: 200880444228 指导教师:冯银波教师职称:讲师 年月日

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