译文
原文题目：State of the art in robotic assembly 译文题目：用机械手装配的发展水平
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State of the art in robotic assembly
Robotic assembly systems offer good perspectives for the rationalization of assembly activities. Various bottlenecks are still encountered, however, in the widespread application of robotic assembly systems. This article focuses on the external developments, bottlenecks and development tendencies in robotic assembly.
External developments
The current market trends are:
Increasing international competition, shorter product life cycle, increasing product diversity, decreasing product quantity, shorter delivery times, higher delivery reliability, higher quality requirements and increasing labour costs. Next to these market developments, technological developments also play a role, offering new opportunities to optimize price, quality and delivery time in their mutual relationships. The technological developments are among other things: information technology, new design strategies, new processing techniques, and the availability of flexible production systems, such as industrial robots. Companies will have to adjust their policy to these market and technology developments (market pull and technology push, respectively). This policy is determined by the company objectives and the company strategy which lie at its basis. Under the influence of the external developments mentioned, the company objectives can, in general, be divided into: high flexibility, high productivity, constant and high product quality, short throughput times, and low production costs. Optimizing these competition factors normally results in the generation of more money, and thus (greater) profits. To realize this objective, most companies choose the following strategies: reduction of complexity, application of advanced production technologies, integral approach, quality control, and improvement of the working conditions. Figure 1 shows the company policy in relation to the external developments to which the company policy should be adjusted.
Figure 1. External developments and company policy
With regard to the product and production development, a subdivision can be made into
the following strategies which involve[1]:
The product: design for manufacturing/assembly, a short development time, a more frequent development of new products, function integration to minimize the number of parts, miniaturization and standardization.
The process: improved controllability, shorter cycle times and minimal stocks. There is a trend increasingly to carry out processes in discrete production in flow form.
The production system: the use of universal, modular, and reliable system components, high system flexibility (in relation to decreasing batch sizes, and increasing product variants), and the integration of product systemsin the entire production.
State of the art
Parts manufacturing and assembly together form coherent sub-processes within the production process. In parts manufacturing, the raw material is processed or transformed into product parts in the course of which the form, sizes and/or properties of the material are changed. In assembly the product parts are put together into subassemblies or into final products. Figure 2 shows the relationships between these functional processes and the most important control processes within an industrial enterprise. This shows that assembly by means of material or product flows is linked to parts manufacturing, and that by means of information flows it is integrated with marketing, product planning, product development, process planning and production control.
Figure 2. Assembly as part of the production process
Assembly forms an important link in the whole manufacturing process, because this operational activity is responsible for an important part of the total production costs and the throughput time. It is one of the most labour-intensive sectors in which the share of the costs of the assembly can amount from 25 to 75 per cent of the total production costs[1]. Research shows that the share of the labour costs in the assembly in relation to the total manufacturing costs is approximately 45 per cent for lorry engines, approximately 55 per cent for machine tools, and approximately 65 per cent for electrical apparatus[1]. The centre of the cost items
moves more and more from the parts manufacturing to the assembly, as automation of the parts manufacturing has been introduced on a larger scale and more consistently than for the assembly. This is mainly due to the complexity of the assembly process and is also a result of assembly unfriendly product designs. As a result, there are high assembly costs. Furthermore, it appears that assembly accounts for approximately 20 to 50per cent of the total throughput time[1].
On the one hand, rationalization and automation of the assembly offer good opportunities to minimize the production costs and the throughput time. However, success depends on numerous factors, such as an integral perception of assembly in conjunction with marketing, product planning, product development, process planning, production control and parts manufacturing (see Figure 2). For this purpose, an assembly-friendly product and process design are of essential importance. Research shows that the design costs of a product amount to only approximately 5 per cent of the manufacturing costs on average, and that the product design influences approximately 70 per cent of these costs. Examples are alternative material choice, differently shaped parts, and/or having one part fulfil various functions. On the other hand, rationalization and automation of the assembly provide the opportunity of taking advantage of external developments, such as increasing product diversity, shorter delivery times, and a shorter product life cycle (see Figure 1).
Except for the complexity of the product and process design, the performance of robotic assembly systems is also determined by the degree of synchronization between the assembly system and the parts manufacturing, the flexibility of the end-effectors and of the peripheral equipment, as well as by the system configuration. In Japan, most robotic assembly systems have a line configuration in contrast with the systems in the USA and Europe. Apart from Europe and the USA, preference is increasingly given to robotic assembly systems in Japan, instead of manual and mechanized systems. The largest area of application of robotic assembly systems in Japan is the electromechanical industry (40 per cent), followed by the car industry (approximately 27 per cent).
Increasingly, robot applications are envisaged for the assembly of complex final products, in several varieties and in low to medium-high production volumes. Research has shown that robotic assembly offers good perspectives in small to medium-size batch production with annual production volumes between 100,000 and 600,000 product compositions per shift. The production volumes for robotic assembly cells lie between approximately 200 and 620 products per hour, and for robotic assembly lines between approximately 220 and 750 products per hour[1].
Bottlenecks
Experience has shown that various bottlenecks still thwart the widespread application of robotic assembly systems. These bottlenecks include: a high complexity of the product and process design, a low quality level of the product parts, as well as product dependence of the peripheral equipment. From a study in Germany into the automation of the assembly process in 355 companies, it appeared that 40 per cent of the companies had an unsuitable product design, 30 per cent had too complex processing of the parts, and 25 per cent had too complex assembly operations[5]. This study confirms the importance of design for assembly(DFA).
The second area in which difficulties occur concerns the limited accuracy ofthe product parts which makes the assembly process unnecessarily complex. This problem can be solved by optimizing the machining processes in the parts manufacturing, and a proper synchronization between the parts manufacturing and the assembly process. The integration of parts manufacture into assembly is also an option.
The third area in which difficulties occur involves the robot and the peripheral equipment. The bottlenecks here are:
1 Limited acceleration an deceleration of robots: resulting in reduced speed.
2 Insufficient means of integrating complex sensors: on the one hand because of the low reliability of these sensors, and on the other hand because of the closeness of robot controllers; a universal language for robotic assembly systems and a standard interface for robot controllers are, unfortunately, not yet available.
3 Limited flexibility of grippers and other assembly tools: owing to the product-dependence of these assembly means, end-effector change is in general required, for which on average 30 per cent of the cycle time will be needed[1].
4 Limited flexibility of the peripheral equipment: this is generally seen as the main bottleneck. The peripheral equipment is often product-dependent, which affects the system flexibility negatively. In this manner, no justice is done to the high flexibility of the robot.
5 Limited reliability of the peripheral equipment and the low accessibility of individual system components: these aspects are greatly influenced by the product complexity and the system configuration[1].
These bottlenecks often result in a higher capital consumption, and a longer cycle time of the assembly system. Insufficient coherence and synchronization between product, process and system design often lie at the basis of this.
Development tendencies
In the past years, numerous DFA methods have been developed to optimize product
design, reducing the complexity of the assembly process and assembly costs[4,6]. These are based on two principles, namely: avoiding assembly operations and simplifying assembly operations[ 1,4,6]. Avoiding assembly operations can be realized, among other things, by modular product design, and eliminating parts as a result of function integration. Assembly operations can be simplified, for example, by taking numerous design rules into account, such as one assembly direction (preferably from top to bottom), the simple feeding, handling and composing of parts, as well as a good accessibility of the assembly location. Figure 3 shows an application for the robotic assembly of gearboxes, with the execution of top to bottom assembly operations.
Figure 3. Robotic assembly of gearboxes (ABB)
In the field of the assembly process, there are also new developments occurring. Especially for the assembly friendly composition of parts, new joining methods are being applied, such as:
1 adhesive bonding;
2 snap fittings. In this manner, a form-closed and force-closed connection can be obtained with small effort;
3 insert and outsert techniques. In this respect, metal or plastic parts are moulded together during the injection moulding process.
Except for developments in the area of product and process design, new developments in the area of robotic assembly systems have emerged under pressure of the bottlenecks mentioned, and under influence of the external developments (see Figure 1). These can be classified as developments which involve the robot, and developments in the area of the peripheral equipment. The developments regarding the robot are:
1 Kinematic and drive: new configurations, lighter constructions, and new drive systems whichguarantee higher speeds and more accuracy.
2 Control: increasingly better controlling and programming facilities, as well as the development of standard interfaces for interactions with the environment, and for communication with control systems higher in the hierarchy. CAD and simulation systems are also increasingly applied for off-line programming of robotic assembly systems[7].
3 Sensors: new developments in the area of optical and tactile sensors offer good opportunities to increase the controllability of the assembly process.
4 End-effectors: new developments in the area of assembly tools and grippers. Especially the integration of optical and tactile sensors, as well as developments in the area of mechanical interfaces, offer in coherence with flexible peripheral equipment the opportunity to assemble various product families in one system.
New developments in the area of the peripheral equipment are:
1 Development of programmable feeding systems and magazines, which can be used for more than one type of part.
2 Integration of sensors in the peripheral equipment for arranging parts and for quality check.
3 Increasing miniaturization, universality, and modularity of system components.
4 The application of automated guided vehicles (AGVs) as transport system.
These developments are particularly initiated by robot manufacturers and technological research institutions, whereas from the viewpoint of industrial engineering, there is mainly interest in new strategies for the development of efficient system layouts, enabling various product variants to be assembled cost efficiently in small batches and in low production volumes. The bottlenecks listed and the development tendencies are summarized in Figure 4.
Figure 4. Bottlenecks and developments tendencies in robotic assembly References
1. Rampersad, H.K., Integrated and Simultaneous Design for Robotic Assembly, John Wiley, Chichester, November 1994.
2. Rampersad, H.K., “A concentric design process”, Advanced Summer Institute in Co-operative Intelligent Manufacturing Systems, Proceedings of the ASI 94, Patras, Greece, June 1994, pp. 158-65.
3. Rampersad, H.K., “Integral and simultaneous design of robotic assembly systems”, paper presented at the Third International Conference on Automation, Robotics and Computer Vision, Singapore, November 199
4.
4. Boothroyd, G. and Dewhurst, P., Design for Robot Assembly, University of
Massachusetts, Armherst, 1985.
5. Schraft, R.D. and Baessler, R., “Possibilities to realize assembly-oriented product design”, Proceedings of the 5th International Conference on Assembly Automation, IFS, Paris, 1984.
6. Rampersad, H.K., “The DFA house”, Assembly Automation, Vol. 13 No. 4, December 1993, pp. 29-36.
7. Drimmelen, M.J., Ram persad, H.K. and Somers, L.J., “Simulating robotic assembly cells: a general model using coloured petri nets”, Proceedings of the International conference on Data and Knowledge Systems for Manufacturing and Engineering, Hong Kong, May 1994, pp. 368-82.
用机械装配的发展水平
机器人装配系统为装配活动提供了合理化良好的发展前景。但是，在机器人装配系统的广泛应用中各种瓶颈依然存在。本文就着眼于说明机器人装配的外部发展瓶颈和发展的趋势。
国外发展情况
目前市场上的发展趋势是：
国际竞争日益加剧，产品生命周期缩短，产品多样性增加，降低产品数量，交货时间缩短，交货的可靠性更高，质量要求更高以及劳动力成本增加。技术的发展也为市场的发展起到了一定的作用，它对优化价格，质量和交货时间的相互关系提供了新的机会。技术发展有其他的东西的发展：信息技术，新的设计战略，新的加工技术和柔性生产系统的可用性，如工业机器人技术的发展。这些市场和技术的发展（市场的拉动和技术推动）将使公司将不得不调整自己的政策。这一政策是在公司目标和战略的基础上确定的。在上述外部发展的影响下，一般来说公司的目标可分为：高弹性，高生产力，不断提高产品质量，吞吐量时间短，生产成本低。优化这些竞争因素通常会赚更多的钱，因此获得（更大的）利润。为了实现这一目标，绝大多数企业选择如下策略：减少复杂性，应用先进的生产技术，整体的方法，质量控制和改善工作条件。图1显示了公司跟上外部发展对公司的发展策略进行调整。
图1 外部发展和公司政策
关于产品和生产的发展，细分可以分为以下策略，包括：
产品：制造/装配设计，发展时间短，新产品更频繁的开发，功能集成，减少零件数量，小型化和标准化。
方法：可控性的改进，较短的周期时间和最低限度的存货。有越来越多的开展流动离散生产过程的趋势。
生产系统：使用通用的、可靠的系统组件，提高系统柔性（相对于减少批量大小，并增加产品的衍生）及产品的整个生产系统的集成。
技术发展水平
在生产过程中零件的制造和装配在一起，形成连贯的子过程。在零件制造，原材料加工或转化为产品的过程中，产品的形式，尺寸或材料性质会发生变化。在装配产品的零件放在一起成为组件或最终产品。图2显示了这些功能的流程之间的关系,最重要的一个工业企业内部控制流程。这表明，物料或产品流是与零部件的制造息息相关的，信息流是市场营销，产品规划，产品开发集成手段，工艺规划与生产控制的结合。
图2 装配生产过程中的一部分
组件在整个生产过程中是一个重要环节，因为这种操作活动是负责总的生产成本和生产时间的一个重要组成部分。劳动力最密集的行业之一的装配成本的份额可占总生产成本的25％至75％。研究表明，组件的总制造成本中的劳动力成本的份额约45％为货车发动机，机床的约55％，而约65％花在电气设备上。零部件制造比装配更加高度自动化，这就使成本中心项目更多的由零部件制造转移到装配。这主要是由于装配
过程中的复杂性也因装配困难的产品设计，这就导致了很高的组装成本。此外，组件的装配占约20％至50％的产品生产时间。
一方面，合理、自动化的装配对减少生产成本和生产时间提供了良好的机会。然而，成功取决于许多因素，如一个整体的产品要与组装、营销，产品规划，产品开发，工艺规划，生产控制和零部件制造（参见图2）结合在一起。为了这个目的，工艺设计对一个装配型的产品具有极其重要的意义。研究表明，设计成本只占约5％的平均制造成本，然而，设计却对约70％的生产成本有影响。例如材料的选择，不同部件形状的不同，和/或一个部件具有各种功能。另一方面，合理化，自动化的装配提供了机会，合理化和自动化的装配对外部发展提供了条件，如增加产品的多样性，更短的交货时间，更短的产品生命周期（见图1）。
除了复杂的产品和工艺设计，机器人装配系统的性能也取受到装配系统及零部件制造之间的同步程度，末端执行器和外围设备的灵活性，以及系统配置的影响。在日本,大多数机器人装配系统与美国和欧洲的系统相比有一个线路配置。除了欧洲和美国，日本人越来越偏好于机器人装配系统，代替手工和机械系统。机器人装配系统的应用领域最大的是日本机电工业（40％），其次是汽车业（27％）。
机械手越来越多的设想应用在一些复杂的低中高生产量的产品最终产品的装配。研究表明，机械手装配可以完成年产量100000和600000产品组成，为小到中等规模的批量生产提供了良好的前景。机械手装配单元的生产量是每小时约200和620之间的产品，一条装配线每小时自动装配约220和750之间的产品。
经验表明，各种瓶颈仍然阻碍机器人装配系统的广泛应用。这些瓶颈包括：高的产品的复杂性和工艺设计，低质量的产品部件的水平，以及对产品外围设备的依赖。从德国355家自动化的装配工艺公司的一项研究中，就出现了40％的公司有不适合的产品设计，30％的过于复杂，难以处理，25％的有太多复杂的装配操作。这项研究证实了装配设计（DFA）的重要性。
第二个领域困难发生涉及有限精度的产品部件,使装配过程不必要的复杂。这个问题可以通过在零部件的制造加工工艺优化及配件的制造和装配过程之间的同步来解决。零件制造为组件的集成也是一个选择。
第三领域的困难涉及机器人和外围设备。这里的瓶颈是：
1 有限加速减速的机器人：降低速度。
2 手段不足：一方面是因为这些传感器可靠性低，另一方面是因为机器人控制器的亲密程度;整合复杂的传感器的机器人装配系统和机器人控制器的标准接口是一种通用的语言，不幸的是，尚未公布。
3 有限的灵活性，夹持器和其他组件的工具：由于这些组件的依赖的产品装置，末端执行器的变化通常是必需的，而这要花费在一个周期平均的30％的时间。
4 外围设备有限的灵活性：这通常被看作是主要的瓶颈。外围设备往往对产品有
依赖性，影响了系统的灵活性。在这种方式中，没有调整的机器人的灵活性高。
5 有限的可靠性的外围设备和单独的系统组件的低可及性：产品的复杂性和系统配置对这些方面有极大的影响。
这些瓶颈往往导致更高的资本消耗，以及更长的循环时间的装配系统。产品，过程和系统设计之间的一致性和同步不足，经常有问题出现。
发展趋势
在过去的几年中，众多的DFA方法已经发展到优化产品设计，减少复杂的装配工艺和装配成本。这些都是基于两个原则，即：避免装配作业，简化装配操作。避免装配操作是可以实现的，在其他事情上，通过模块化的产品设计，消除部分功能集成。组件可以简化操作，例如，以众多的设计规则的考虑，如装配方向（最好是从上到下），简单的进料，处理和组成部分，以及装配位置的可达性好。图3显示了变速箱装配机械手的应用，它在执行装配操作。
图3 变速箱装配机械手
在装配过程中，也有一些新的事态发展。特别是对零件装配性能好的组合物，新加入的方法被应用，如：
1 粘合；
2 弹簧配件。在这种方式中，一种形成闭合和强力封闭连接可以起到作用；
3 插入和标签技术。在这方面，金属或塑料零件的注射成型过程中模压在一起
除了在产品和工艺设计领域的发展，在前面提到的压力下及外部发展的影响机器人在装配系统领域的新发展已经出现了瓶颈（见图1）。发展涉及机器人和发展的区域中的外围设备，关于机器人的发展是：
1 运动学和驱动器：新的配置，更轻的结构，和新的驱动器系统以保证更高的速度和更高的精度。
2 控制：日益更好地控制和编程设施，以及开发标准接口，用于与环境的相互作用，以及更高层次的通信与控制系统，也越来越多地应用于CAD和仿真系统离线编程的机器人装配系统。
3 传感器：光学和触觉传感器领域的新的发展提供了良好的机会，以提高装配过程中的可控性。
4 末端效应器：新的发展是在该领域的装配工具和夹具。尤其是集成光学和触觉感应器，以及机械接口在该领域的发展，提供灵活的外围设备，组装在一个系统中的各种产品系列的连贯性。
在外围设备的领域新的发展是：
1 可编程送料系统和杂志，其中一个以上的类型的部件可用于发展。
2 用于放置的零件和质量检查的集成外围设备中的传感器。
3 日趋小型化，普遍性，和模块化的系统组件。
4 自动导引车（AGV的运输系统）的应用。
这些发展是由机器人制造商和技术研究机构特别发起，而从工业工程的角度来看，主要集中在新策略，高效的系统布局的发展，使各种小批量和低产量变体产品装配成本有效降低。图4了总结了机械手的发展瓶颈和发展趋势。
图4 用机械手装配的瓶颈和发展的趋势
参考文献
[1] Rampersad, H.K., Integrated and Simultaneous Design for Robotic Assembly, John Wiley, Chichester, November 1994.
[2] Rampersad, H.K., “A concentric design process”, Advanced Summer Institute in Co-operative Intelligent Manufacturing Systems, Proceedings of the ASI 94, Patras, Greece, June 1994, pp. 158-65.
[3] Rampersad, H.K., “Integral and simultaneous design of robotic assembly systems”, paper presented at the Third International Conference on Automation, Robotics and Computer Vision, Singapore, November 1994.
[4] Boothroyd, G. and Dewhurst, P., Design for Robot Assembly, University of Massachusetts, Armherst, 1985.
[5] Schraft, R.D. and Baessler, R., “Possibilities to realize assembly-oriented product design”, Proceedings of the 5th International Conference on Assembly Automation, IFS, Paris, 1984.
[6] Rampe rsad, H.K., “The DFA house”, Assembly Automation, Vol. 13 No. 4, December 1993, pp. 29-36.
[7] Drimmelen, M.J., Rampersad, H.K. and Somers, L.J., “Simulating robotic assembly cells:
a general model using coloured petri nets”, Proceedings of the Internation al conference on Data and Knowledge Systems for Manufacturing and Engineering, Hong Kong, May 1994, pp. 368-82.
外文出处： 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题： JDBC接口技术 译文： JDBC是一种可用于执行SQL语句的JavaAPI（ApplicationProgrammingInterface应用程序设计接口）。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口，使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC，很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢？如果有，那么它们之间又是怎样的关系呢？ ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统（DBMS）中存取数据的，用C语言实现的，标准应用程序数据接口。通过ODBCAPI，应用程序可以存取保存在多种不同数据库管理系统（DBMS）中的数据，而不论每个DBMS使用了何种数据存储格式和编程接口。 1．ODBC的结构模型 ODBC的结构包括四个主要部分：应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口：屏蔽不同的ODBC数据库驱动器之间函数调用的差别，为用户提供统一的SQL编程接口。 驱动器管理器：为应用程序装载数据库驱动器。 数据库驱动器：实现ODBC的函数调用，提供对特定数据源的SQL请求。如果需要，数据库驱动器将修改应用程序的请求，使得请求符合相关的DBMS所支持的文法。 数据源：由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器，以便ODBC函数调用，但是数据库驱动器本身也执行ODBC函数调用，并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时，数据库驱动器能管理通信协议。当建立起与数据源的连接时，数据库驱动器便能处理应用系统向DBMS发出的请求，对分析或发自数据源的设计进行必要的翻译，并将结果返回给应用系统。 2．JDBC的诞生 自从Java语言于1995年5月正式公布以来，Java风靡全球。出现大量的用java语言编写的程序，其中也包括数据库应用程序。由于没有一个Java语言的API，编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥，比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱，越来越多的公司在Java程序开发上投入的精力日益增加，对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处，比如它并不容易使用，没有面向对象的特性等等，SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1．x 版本中，JDBC只是一个可选部件，到了JDK1．1公布时，SQL类包（也就是JDBCAPI）
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
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
附录一英文科技文献翻译 英文原文： Experimental investigation of laser surface textured parallel thrust bearings Performance enhancements by laser surface texturing (LST) of parallel-thrust bearings is experimentally investigated. Test results are compared with a theoretical model and good correlation is found over the relevant operating conditions. A compari- son of the performance of unidirectional and bi-directional partial-LST bearings with that of a baseline, untextured bearing is presented showing the bene?ts of LST in terms of increased clearance and reduced friction. KEY WORDS: ?uid ?lm bearings, slider bearings, surface texturing 1. Introduction The classical theory of hydrodynamic lubrication yields linear (Couette) velocity distribution with zero pressure gradients between smooth parallel surfaces under steady-state sliding. This results in an unstable hydrodynamic ?lm that would collapse under any external force acting normal to the surfaces. However, experience shows that stable lubricating ?lms can develop between parallel sliding surfaces, generally because of some mechanism that relaxes one or more of the assumptions of the classical theory. A stable ?uid ?lm with su?cient load-carrying capacity in parallel sliding surfaces can be obtained, for example, with macro or micro surface structure of di?erent types. These include waviness [1] and protruding microasperities [2–4]. A good literature review on the subject can be found in Ref. [5]. More recently, laser surface texturing (LST) [6–8], as well as inlet roughening by longitudinal or transverse grooves [9] were suggested to provide load capacity in parallel sliding. The inlet roughness concept of Tonder [9] is based on ??e?ective clearance‘‘ reduction in the sliding direction and in this respect it is identical to the par- tial-LST concept described in ref. [10] for generating hydrostatic e?ect in high-pressure mechanical seals. Very recently Wang et al. [11] demonstrated experimentally a doubling of the load-carrying capacity for the surface- texture design by reactive ion etching of SiC
机械设计理论 机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。它涉及工程技术的各个领域，主要研究产品的尺寸、形状和详细结构的基本构思，还要研究产品在制造、销售和使用等方面的问题。 进行各种机械设计工作的人员通常被称为设计人员或者机械设计工程师。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性，还必须在机械制图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。如前所诉，机械设计的目的是生产能够满足人类需求的产品。发明、发现和科技知识本身并不一定能给人类带来好处，只有当它们被应用在产品上才能产生效益。因而，应该认识到在一个特定的产品进行设计之前，必须先确定人们是否需要这种产品。 应当把机械设计看成是机械设计人员运用创造性的才能进行产品设计、系统分析和制定产品的制造工艺学的一个良机。掌握工程基础知识要比熟记一些数据和公式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的全部决定的。另一方面，应该认真精确的进行所有运算。例如，即使将一个小数点的位置放错，也会使正确的设计变成错误的。 一个好的设计人员应该勇于提出新的想法，而且愿意承担一定的风险，当新的方法不适用时，就使用原来的方法。因此，设计人员必须要有耐心，因为所花费的时间和努力并不能保证带来成功。一个全新的设计，要求屏弃许多陈旧的，为人们所熟知的方法。由于许多人墨守成规，这样做并不是一件容易的事。一位机械设计师应该不断地探索改进现有的产品的方法，在此过程中应该认真选择原有的、经过验证的设计原理，将其与未经过验证的新观念结合起来。 新设计本身会有许多缺陷和未能预料的问题发生，只有当这些缺陷和问题被解决之后，才能体现出新产品的优越性。因此，一个性能优越的产品诞生的同时，也伴随着较高的风险。应该强调的是，如果设计本身不要求采用全新的方法，就没有必要仅仅为了变革的目的而采用新方法。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不受各种约束。即使产生了许多不切实际的想法，也会在设计的早期，即绘制图纸之前被改正掉。只有这样，才不致于堵塞创新的思路。通常，要提出几套设计方案，然后加以比较。很有可能在最后选定的方案中，采用了某些未被接受的方案中的一些想法。
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
本科毕业论文(设计) 外文翻译 学院：机电工程学院 专业：机械工程及自动化 姓名：高峰 指导教师：李延胜 2011年05 月10日 教育部办公厅 Failure Analysis，Dimensional Determination And
Analysis，Applications Of Cams INTRODUCTION It is absolutely essential that a design engineer know how and why parts fail so that reliable machines that require minimum maintenance can be designed．Sometimes a failure can be serious，such as when a tire blows out on an automobile traveling at high speed．On the other hand，a failure may be no more than a nuisance．An example is the loosening of the radiator hose in an automobile cooling system．The consequence of this latter failure is usually the loss of some radiator coolant，a condition that is readily detected and corrected．The type of load a part absorbs is just as significant as the magnitude．Generally speaking，dynamic loads with direction reversals cause greater difficulty than static loads，and therefore，fatigue strength must be considered．Another concern is whether the material is ductile or brittle．For example，brittle materials are considered to be unacceptable where fatigue is involved． Many people mistakingly interpret the word failure to mean the actual breakage of a part．However，a design engineer must consider a broader understanding of what appreciable deformation occurs．A ductile material，however will deform a large amount prior to rupture．Excessive deformation，without fracture，may cause a machine to fail because the deformed part interferes with a moving second part．Therefore，a part fails(even if it has not physically broken)whenever it no longer fulfills its required function．Sometimes failure may be due to abnormal friction or vibration between two mating parts．Failure also may be due to a phenomenon called creep，which is the plastic flow of a material under load at elevated temperatures．In addition，the actual shape of a part may be responsible for failure．For example，stress concentrations due to sudden changes in contour must be taken into account．Evaluation of stress considerations is especially important when there are dynamic loads with direction reversals and the material is not very ductile． In general，the design engineer must consider all possible modes of failure，which include the following． ——Stress ——Deformation ——Wear ——Corrosion ——Vibration ——Environmental damage ——Loosening of fastening devices
I / 11 本科毕业设计外文翻译 <2018届） 论文题目基于WEB 的J2EE 的信息系统的方法研究 作者姓名[单击此处输入姓名] 指导教师[单击此处输入姓名] 学科(专业 > 所在学院计算机科学与技术学院 提交日期[时间 ]
基于WEB的J2EE的信息系统的方法研究 摘要：本文介绍基于工程的Java开发框架背后的概念，并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复，而且并不总是符合最佳实践，所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式，代表有效解决办法的工具。开发框架提供：<1）从用户界面到数据集成的应用程序开发堆栈；<2）一个架构，基本环境及他们的相关技术，这些技术用来使用其他一些框架。架构定义了一个开发方法，其目的是协助客户开发工程。 关键词：J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台，以实现他们的用户界面，科学分析，分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此，WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平，使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下，开源框架没有提供常见问题的一个解决方案。出于这个原因，开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架，该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架，本文提出了新的架构，基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法，其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求，也
机械类外文翻译 塑料注塑模具浇口优化 摘要:用单注塑模具浇口位置的优化方法，本文论述。该闸门优化设计的目的是最大限度地减少注塑件翘曲变形，翘曲，是因为对大多数注塑成型质量问题的关键，而这是受了很大的部分浇口位置。特征翘曲定义为最大位移的功能表面到表面的特征描述零件翘曲预测长度比。结合的优化与数值模拟技术，以找出最佳浇口位置，其中模拟armealing算法用于搜索最优。最后，通过实例讨论的文件，它可以得出结论，该方法是有效的。 注塑模具、浇口位臵、优化、特征翘曲变形关键词: 简介 塑料注射成型是一种广泛使用的，但非常复杂的生产的塑料产品，尤其是具有高生产的要求，严密性，以及大量的各种复杂形状的有效方法。质量ofinjection 成型零件是塑料材料，零件几何形状，模具结构和工艺条件的函数。注塑模具的一个最重要的部分主要是以下三个组件集:蛀牙，盖茨和亚军，和冷却系统。拉米夫定、Seow(2000)、金和拉米夫定(2002) 通过改变部分的尼斯达到平衡的腔壁厚度。在平衡型腔充填过程提供了一种均匀分布压力和透射电镜,可以极大地减少高温的翘曲变形的部分～但仅仅是腔平衡的一个重要影响因素的一部分。cially Espe,部分有其功能上的要求,其厚度通常不应该变化。 pointview注塑模具设计的重点是一门的大小和位臵,以及流道系统的大小和布局。大门的大小和转轮布局通常被认定为常量。相对而言,浇口位臵与水口大小布局也更加灵活,可以根据不同的零件的质量。 李和吉姆(姚开屏,1996a)称利用优化流道和尺寸来平衡多流道系统为multiple 注射系统。转轮平衡被形容为入口压力的差异为一多型腔模具用相同的蛀牙,也存
Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method
沈阳工业大学工程学院 毕业设计（论文）外文翻译 毕业设计（论文）题目：工具盒盖注塑模具设计 外文题目：Friction , Lubrication of Bearing 译文题目：轴承的摩擦与润滑 系（部）：机械系 专业班级：机械设计制造及其自动化0801 学生姓名：王宝帅 指导教师：魏晓波 2010年10 月15 日
外文文献原文： Friction , Lubrication of Bearing In many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement. Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener and the parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary. The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. Also , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt. There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding, and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. To produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement . Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. As shown in figure ,starting friction is always greater than sliding friction . Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the added energy required to keep the parts turning and overcome friction. The friction caused by the wedging action of surface irregularities can be overcome
毕业设计（论文） 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年
研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院，中国南京，邮编210098 nzg_197901@https://www.doczj.com/doc/f215343618.html,，niuzhiguo@https://www.doczj.com/doc/f215343618.html, 李同春 河海大学水利水电工程学院，中国南京，邮编210098 ltchhu@https://www.doczj.com/doc/f215343618.html, 摘要 由于钢弧形闸门的结构特征和弹力，调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中，简化空间框架作为分析模型，根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型，动态不稳定区域的弧形闸门可以通过有限元的方法，应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外，结合物理和数值模型，对识别新方法的参数共振钢弧形闸门提出了调查，本文不仅是重要的改进弧形闸门的参数振动的计算方法，但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力，没有门槽，好流型，和操作方便等优点，使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门，通过门叶和主大梁，所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂，手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中，除了极特殊的破坏情况下，弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外，明显的动态作用下发生破坏。例如:张山闸，位于中国的江苏省，包括36个弧形闸门。当一个弧形闸门打开放水时，门被破坏了，而其他弧形闸门则关闭，受到静态静水压力仍然是一样的，很明显，一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。
Section 3 Design philosophy, design method and earth pressures 3.1 Design philosophy 3.1.1 General The design of earth retaining structures requires consideration of the interaction between the ground and the structure. It requires the performance of two sets of calculations: 1）a set of equilibrium calculations to determine the overall proportions and the geometry of the structure necessary to achieve equilibrium under the relevant earth pressures and forces; 2）structural design calculations to determine the size and properties of thestructural sections necessary to resist the bending moments and shear forces determined from the equilibrium calculations. Both sets of calculations are carried out for specific design situations (see 3.2.2) in accordance with the principles of limit state design. The selected design situations should be sufficiently Severe and varied so as to encompass all reasonable conditions which can be foreseen during the period of construction and the life of the retaining wall. 3.1.2 Limit state design This code of practice adopts the philosophy of limit state design. This philosophy does not impose upon the designer any special requirements as to the manner in which the safety and stability of the retaining wall may be achieved, whether by overall factors of safety, or partial factors of safety, or by other measures. Limit states (see 1.3.13) are classified into: a) ultimate limit states (see 3.1.3); b) serviceability limit states (see 3.1.4). Typical ultimate limit states are depicted in figure 3. Rupture states which are reached before collapse occurs are, for simplicity, also classified and