人人文库网 > 图纸下载 > 毕业设计 > 精密平面磨床微进给及微位移工作台设计【4张CAD图纸和说明书】

设计说明书.doc

精密平面磨床微进给及微位移工作台设计【4张CAD图纸和说明书】

资源目录

精密平面磨床微进给及微位移工作台设计【4张CAD图纸和说明书】.zip

设计说明书.doc---(点击预览)

相关资料.doc---(点击预览)

修整器零件图.dwg

垂直轴零件改图.dwg

垂直进给机构装配图1.dwg

微位移图.dwg

压缩包内文档预览：(预览前20页/共45页)

编号：6039333 类型：共享资源大小：1.40MB 格式：ZIP 上传时间：2017-10-26 上传人：俊****计 IP属地：江苏

40
积分

版权申诉 word格式文档无特别注明外均可编辑修改；预览文档经过压缩，下载后原文更清晰！ 立即下载

关键词：: 精密平面磨床进给位移工作台设计 4张 cad 图纸说明书

资源描述：

摘要

随着科学技术的发展和高新技术产业的需要，精密平面磨床已然在当代制造产业中占据了非常重要的地位。本文在收集了大量资料和吸取了前辈们的经验的情况下，设计了一台以广州机械制造厂的MGB6120为原型、以微进给机构和微位移系统来提升加工精度的精密平面磨床工作。在此基础上，完成了该磨床的总体设计计算，并进行了数据对比优化选择，取得以下研究成果：

(1) 设计一台精密数控平面磨床，用砂轮周边磨削平面和台阶平面，用于机械制造业及工具模具制造业，且能加工各种难加工材料。

(2) 确定了该精密平面磨床工作台的各个部件及其功能分配，完成了该平面磨床的传动选择以及总体布局设计。

(3) 利用滚珠丝杆为主要器件，结合梯形螺纹丝杆压杆来检测其稳定性；通过压电、电致伸缩器件在微位移系统中的压电耦合效应和砂轮修整器特性提高了该工作台的加工精度。

(4) 将840D数控技术作用于平面磨床工作台并选择西门子IFK6交流伺服电机作为进给机构和微位移系统的电力源，完成了精密平面磨床微进给及微位移工作台的设计。

关键词：精密；微位移；微进给；砂轮器；数控

Abstract

With the development of science and technology and the need of high-technique industry, precision surface grinder has played a very important role in modern manufacturing industry. Under the circumstance of collecting a great number of materials and absorbing predecessors' experience, this article designs a precision surface grindering machine which is the prototype of MGB6120 in Guangzhou machine tool. In addition, it improves precision by a micro feed mechanism and a micro displacement system. In that case, it finish the calculation of the overall design of the grinding machine. What's more, it makes the optimization of comparative data and obtains the following results：

(1) It designs a precision NC grinding machine and grinds surface with grinding wheel. It is used in mechanical manufacturing industry and model manufacturing industry. It also processes various materials which are very difficult.

(2) It confirms each component and function allocation of precision surface grinder worktable. It also finishes the transmission selection and overall layout.

(3) It regards ball screw rod as main device and is combined with the trapezoidal thread screw rod to test its stability. Piezoelectric coupling effect and grinding wheel dressing device features, which improve the machining accuracy of the workbench through the piezoelectric and electrostrictive devices in the micro displacement system.

(4) It uses 802D in NC plane grinder worktable and chooses Siemens IFK6 AC servo motor as the power source for the feeding mechanism and micro displacement system. It also completes the design of precision surface grinder micro-feed and micro displacement worktable.

Key words: precision, micrometric displacement, micro-feeding, Grinding wheel. CNC (computerized numerical control)

摘要 III

Abstract IV

目录 V

1 绪论 1

1.1 本课题的研究背景和意义 1

1.2 国内外精密平面磨床的发展概况 1

1.2.1 国外精密加工数控车床技术发展概况 1

1.2.2 国内精密加工数控车床技术发展概况 3

1.3本课题的设计任务说明 5

1.3.1 毕业设计任务与论文组成 5

1.3.2 本课题的研究方法 5

2 精密平面磨床的总体设计 6

2.1 引言 6

2.2 磨床技术规格 6

2.3 磨床总体布局设计 7

2.4 磨床的传动设计 7

2.5 磨床主要组成部件及其功能 8

2.6 进给机构的分类及使用方法 8

2.7 本章小结 9

3 砂轮的特性和修整 10

3.1 砂轮的特性 10

3.2 砂轮修整器 11

3.2.1 砂轮修整器的设计 11

3.2.2 修整器摆角的设计 14

3.3 砂轮修整的展望 15

3.4 本章小结 15

4 微位移系统 17

4.1 引言 17

4.2 微位移技术的分类 17

4.3 微位移系统的广泛实用性 19

4.3.1 微位移器件在磨床中所需要具备的条件 20

4.3.2 微位移行程的提高 20

4.4 压电、电致伸缩器件在微位移系统结构中的优点 20

4.4.1 压电与电致伸缩效应——机电偶合效应 20

4.5 微位移系统的结构设计 21

4.5.1 微位移工作台的组成 21

4.5.2 微位移工作台工作原理 21

4.5.3 板弹簧的设计与用途 22

4.5.4 预紧力与系统分辨率 22

4.6本章小结 23

5 微进给机构系统的设计 24

5.1 微进给机构的结构和特点 24

5.2 确定微进给机构设计方案 25

5.2.1 对微量自动进给机构的基本要求： 26

5.3 滚珠丝杆副的优点 26

5.3.1 滚珠丝杆的设计计算 26

5.3.2 梯形螺纹丝杆压杆稳定性校核 28

5.4 垂直微进给电机的功率计算 28

5.5 本章小结 29

6 数控硬件电路设计 30

6.1 引言 30

6.2 840D数控系统说明 30

6.3 840D数控系统组成 30

6.4 840D数控系统的连接 30

6.5 本章小结 32

结论和展望 33

致谢 34

参考文献 35

1 绪论

1.1 本课题的研究背景和意义

二十一世纪，随着科学技术的飞速发展，现代制造工业正以全新的面貌展现在世人面前。其中，精密加工技术的发展显而易见。精密加工技术及磨床在机械制造业中占有极其重要的位置。

根据先进技术的实用性和先进性而论，精密加工技术追求加工上的精度和表面质量极限；制造自动化包括了产品设计、制造和管理的自动化，它不仅是快速市场需求的快速响应，而且是提高生产效率，改善劳动条件的重要手段。两者有着密切关系，许多精密加工需要自动化技术得以达到预期指标，而制造自动化基本赖于精密加工才能准确可靠的实现。两者的全局性和决定性奠定了它们是先进制造技术的支柱。

众多国家都十分重视先进制造技术的水平和发展，精密加工技术显然已经是一个国家进行产品革新、扩大生产和提高国际经济竞争能力。从先进制造技术的技术实质性而论，精密加工技术追求加工上的精度和表面质量极限；制造自动化包括了产品设计、制造和管理的自动化，它不仅是快速市场需求的快速响应，而且是提高生产效率，改善劳动条件的重要手段。两者有着密切关系，许多精密加工需要自动化技术得以达到预期指标，而制造自动化基本赖于精密加工才能准确可靠的实现。两者的全局性和决定性奠定了它们是先进制造技术的支柱。微进给机构的研究与设计，便是精先进制造技术的集中体现之一。

微进给机构一般指行程范围为毫米级：位移分辨率及定位精度达到纳米级的位移机构。微进给机构通常由微位移器和精密导轨两部分组成，其技术研究不仅关系到超精密磨床研制，更是精密机械、微电子、生物工程等多种学科赖以发展的基础。因此开展微进给机构工作台的研究与设计是非常有必要且具有更广阔的应用前景。

1.2 国内外精密平面磨床的发展概况

国内外都采用超精密磨削、精密修整、微细磨料磨具进行亚微米级以下切深磨削的研究，以获得亚微米级的尺寸精度。

1.2.1 国外精密加工数控车床技术发展概况

发展精密加工磨床是发展精密加工技术的十分重要的内容，歌发达国家都发展了很多种精密机床。精密加工磨床也向着高精度、多功能和高效专用方向发展。

美国是开展精密加工技术研究最早的国家， 20实际30年代开始，在制造技术上处于世界领先地位，但在50年代以后，对制造技术没有给予足够的重视，在经济竞争上感受到巨大的威胁，经过认真总结，80年代后，在重要的、高速增长的技术市场上失利的一个重要原因就是没有把自己先进的技术应用到制造产业上。如今，美国国家工程科学院的国家研究理事会经过反复研究，提出不能像前些年那样把制造归属于设计的地位上，而是要把注意力重新放在制造技术上。美国利用自己已有的成熟单元技术，只用两周的时间便组装成了一台小型的超精密加工车床（BODTM 型），用刀尖半径为的单晶金刚石刀具，实现切削厚度为的加工。尽管如此，最近美国政府还是继续把微米级和纳米级的加工技术作为国家的关键技术之一，这足以说明美国对这一技术的重视。

德国JUNG公司是国际上知名较高的平面磨床生产厂商，在40余年的生产过程中，该公司的平面和成型磨床以精度高、使用寿命长而著称。JUNG公司的主要平面磨床产品均采用立柱升降式，外形小巧，磨削精度高。工作台纵向运动一般都设二套运动装置，往复运动由液压驱动，缓进给成型磨削采用机电传动。其中水平较高的是JF520CNC B型四坐标数控平面和成型磨床。

该机采用高精度连续轨迹控制以图形辅助操作，控制系统是以西门子SINUMERIK810为基础，配用JUNG公司开发的专用软，一反传统结构，首次采用了龙门式框架结构，可以满足大尺寸工件和新型工程材料的精密磨削加工需要。图1.1和图1.2分别为大型磨床和手动数控磨床。

全部文件.jpg

垂直进给机构装配图1.gif

垂直轴零件改图.gif

微位移图.gif

修整器零件图.gif

字数统计.gif

内容简介：: 无锡太湖学院毕业设计（论文）开题报告题目：精密平面磨床微进给及微位移工作台设计信机系机械工程及自动化专业学号： 0923150 学生姓名：邱文浩指导教师：范圣耀（职称：副教授）（职称：副教授）2013 年 1 月 15 日课题来源自拟题目科学依据（1）课题科学意义当代社会，制造业特别是机械制造业是国民经济的支柱产业，现代制造业正在改变着人们的生产方式、生活方式、经营管理模式乃至社会的组织结构和文化。由于中国潜在的巨大市场和丰富的劳动力资源，世界的制造业正在向中国转移，中国正在成为世界的制造大国。我国在家电等若干产品的产量已居世界第一位。但是在自主知识产权的创新设计、先进制造工艺和装备及现代化管理等方面仍然存在很大差距，所以我们还没还不是领先于世界的制造强国。机械制造业是国民经济和社会发展的物质基础，是一个国家综合国力的重要体现。伴随经济全球化，我国正在成为世界机械制造业的中心，但是与发达国家相比，我国机械制造业不仅制造工艺装备陈旧、生产自动化技术落后，企业管理粗放、缺乏自主创新产品与先进技术等，而且在快速、高品质、低成本，以及优质服务方面也有较大的差距。因此正确分析我国机械制造业的品牌优势、技术优势和成本优势，并依据不同类型制造业的特点，有针对性地提出制造业的信息化战略对策具有重要意义。（2）精密加工技术的研究状况及其发展前景精密和超精密制造技术是当前各个工业国家发展经济的核心技术之一,因此了解精密与超精密加工的国内外发展状况及发展趋势对我国发展装备制造业具有十分重要的意义。目前精密加工所能达到的加工精度距加工的极限还有相当的距离。国外有人声称已开发了以原子级去除单位的加工方法，但目前还未在实际生产中得到应用。为了促进精密加工技术的发展，应深入研究和探讨下列几个问题，即发展前景：(1)努力开发加工单位极小的精密加工方法；(2)开发精密的机械机构；(3)开发高精度的检测系统；(4)开发适用于精密加工并能获得高精度、搞表面质量的新型材料。研究内容设计一台精密数控平面磨床，用砂轮周边磨削平面，也可以磨削台阶平面、能用于机械制造业及工具磨具制造业，能加工各种难加工材料（如陶瓷材料）；磨床总体设计方案确定，绘制机床总体布局图；砂轮修整器设计计算；垂直进给机构的设计，伺服电机和滚珠丝杠副设计计算，绘制垂直进给机械结构的装配图；结合数控技术的微位移工作台的设计；拟采取的研究方法、技术路线、实验方案及可行性分析实验方案设计一台精密数控平面磨床，用砂轮周边磨削平面和台阶平面，用于机械制造业及工具模具制造业，且能加工各种难加工材料。确定了该精密平面磨床工作台的各个部件及其功能分配，完成了该平面磨床的传动选择以及总体布局设计。利用滚珠丝杆为主要器件，结合梯形螺纹丝杆压杆来检测其稳定性；通过压电、电致伸缩器件在微位移系统中的压电耦合效应和砂轮修整器特性提高了该工作台的加工精度。将 840D 数控技术作用于平面磨床工作台并选择西门子 IFK6 交流伺服电机作为为进给机构和微位移系统的电力源，完成了精密平面磨床微进给及微位移工作台的设计。研究计划及预期成果研究计划：2012 年 10 月 28 日-2012 年 11 月 28 日：学习并翻译一篇与毕业设计相关的英文材料。2012 年 12 月 01 日-2013 年 01 月 30 日：按照任务书要求查阅论文相关参考资料，填毕业设计开题报告书。2013 年 01 月 25 日-2013 年 02 月 10 日：填写毕业实习报告。2013 年 02 月 20 日-2013 年 03 月 20 日：按照要求修改毕业设计开题报告。2013 年 03 月 20 日-2013 年 04 月 30 日：微进给机构微位移系统设计。2013 年 05 月 01 日-2010 年 05 月 21 日：毕业论文撰写和修改工作。预期成果：这套低成本、高效率、高可靠性、人性化精密平面磨床，能在市场竞争中处于有利地位。微进给及微位移技术的应用范围广泛,其推广应用社会经济效益十分显著,国内制造业水平有显著的提高。特色或创新之处使用 840D 数控系统，效果明显，方便改变参量，能有效的提高加工工件的精度。采用固定某些参量、改变某些参量来研究问题的方法，思路清晰，简洁明了，行之有效。已具备的条件和尚需解决的问题图书馆中提供了大量的资料，包括前辈们辛苦的劳动成果，使得我可以像站在巨人肩膀上一样来设计课题，当然，由于学生的条件约束性，不能到工厂进行实际装配操作，理论依据也有待完善。指导教师意见指导教师签名：年月日教研室（学科组、研究所）意见教研室主任签名：年月日系意见主管领导签名：年月日英文原文THE PROGRAMMES OF MODERN MECHANICAL DESIGNThe mechanical design of products that is not purely mathematical calculations using the methods, also difficult to use mathematical models to describe the complete, and must be in accordance with product features Formal description help design expert knowledge and experience for reasoning and decision-making. Thus, for the purpose of computer-aided design products, the need to address the use of computer storage and product design knowledge and design experts, and other parties to the decision-making problem, The resulting product characteristics of knowledge-based design methods. At present, the intelligent design method is to use 3D graphics software and virtual reality technology in design, visualization better, Users can develop early in a certain degree of direct participation in the design, but systemic poor, and parts of the structure, shape, Size, location to determine the reasonable, demand software with high degree of intelligence, or have extensive experience in the designers. 2, the modular design structure From the perspective of planning products : definition of design tasks to the functional structure-based products, The product has been used solutions (such as common parts and components, etc.) to describe the design task, That the decomposition of tasks on each task to consider whether there are corresponding to the product solution, so that in the product planning stage design tasks to eliminate potential conflicts, early production forecasts, costs, and the development of the design process of adjustment, which can improve design efficiency and reliability, while also reducing the cost of new product. Feldmann will describe the design of the function of the product mix is divided into four tiers, (1) Product (2) functional components (3) major functional components (4) functional components. And using application-oriented features of the directory structure, the functional components for more specific qualitative and quantitative description. Meanwhile developed products suited to the development of an early design stage and the use of the software tools STRAT. That the majority of machinery specialized functions can be used existing product solutions, and with the new solution is only a small number of special features, Therefore, the exclusive use of mechanical design functions of the product mix, machinery specialized for the evaluation of the design, manufacturing risks are very favorable. Promotion of the product function on the basis of the analysis, will be divided into products with a particular function in one or several of the basic modular structure, through options and combinations of these basic modular structure formed into different products. These basic structures can be parts, components, or even a system. Ideal modular structure should have a standardized interface (Department of connectivity and tie), and is serialized, and generalized, integrated, hierarchical, flexible, economy, interchangeability is, compatibility and relevance. Chinas combination of software component technology and CAD technology, design and deformation of composite design combined according to the classification modular theory, machine processing center will be divided into small and product level, component level, component level and component level, and the use of expert knowledge and technology to their CAD portfolio into different varieties, the functional module specifications, by the combination of these functional modules into different processing center overall program. The design for the directory as a choice variation mechanical structure tools, design elements for the solution of integrity, Structure of the organization formed Solution Set design catalog. And the solution set design directory listed a comment on each of Additional Information Solutions, is very conducive to the solution design engineers to choose elements. According to the mechanical parts connectivity features, be grouped into four types : 1) direct inter-positioning components, and self-adjustment of components; 2) structure common to the assembly; 3) having a nested structure and nested components connectivity; 4) modular structure with modular components and connectivity. And the potential use of symbols said typical components and the connecting element rules, This realization of the connection between the components of the algorithm and the concept of visualization.Mechanical systems during the design, the functional establishment of a module to function decomposition, and a functional decomposition of the best pills with the degree of functional institutions type correspondence. Structure establishment of a module, as a functional solution of choice in order to achieve mapping algorithm. 2, the characteristics of knowledge-based Product design knowledge-based product design characteristics of the main features : using computers to identify the language to describe the characteristics of the product and its design experts in the field of knowledge and experience, corresponding inference engine and knowledge base, Reuse stored domain knowledge and reasoning mechanism established by the Computer Aided Design program. Mechanical systems design is mainly based on the products with the characteristics and the design of experts in the field of knowledge and experience in policy-making and implementation capacity, completing the type, consolidated. To achieve this stage of the computer-aided design, research must automatic acquisition of knowledge, expression, integration, coordination, management and use. To this end, scholars at home and abroad design mechanical systems design knowledge of automated processing done a lot of research work, The method can be summarized in the following several. 2.1coding method Under the conversion campaign functions (functions) to organizations classified, and the use of codes to describe functional yuan and the institutional category, which established the System Design Expert System knowledge base. On this basis, binary logic and fuzzy theory combined the establishment of the expert systems of the reasoning mechanism, and work spaces for four Special Machine Design program. Use of the theory of biological evolution through natural selection and sexual reproduction to the evolution of organisms principle, At the institutional design, the use of network theory to map the structure of expression topology map, and through the coding technology put the structure and properties of individual chromosome into a binary string of a few, and prepared in accordance with the design requirements fitness, use of the theory of biological evolution control reproductive mechanism, through selection, crossover, sudden variations, and other means adapt to the low value out unsuitable individuals, a rapid evolutionary process is the optimal adaptive individual, that is the best design requirements of agency programs. 2.2 knowledge mixed expressions Complex mechanical systems design, adoption of hybrid knowledge expression to describe the design of all types of knowledge is particularly well-suited, This has been our design many scholars consensus. In the development of complex product design intelligent decision support system DMDSS, to the rules, frameworks, process and neural network methods of knowledge representation and combined with the design to suit different types of knowledge described. Of a single variety of methods of knowledge representation (rules, the framework and process), according to the object-oriented programming principles. with the framework of the slots said the attribute with the rules said the dynamic characteristics of objects using a process that knowledge, A mixed composition of the knowledge expression patterns, and successfully developed the object-oriented NC milling machine gearbox design GBCDIS intelligent system and change Speed box structure design expert system GBSDES. 2.3 the use of knowledge-based development tools Coupling in the CAD system, the use of knowledge-based development tools NEXPERT - DCOM. using the object-oriented methods, the creation of object-oriented database design, Coupling of designers for the design and structural design provides a broad and reliable design spectrum. NEXPERT is using the linear guide describes the design needs to be based on knowledge of the design, This seeking out of knowledge-based solutions, and develop linear guideway design expert system.2.4 Design of Contents Construction of modules, functional element solution and body three progressive design directory, This will be three progressive design directory as a mechanical transmission programs Intelligent Design Theory of Knowledge Base system design and development support tools. 2.5 Based on the example of the method In the development of expert system-based design of the knowledge base, using the basic description of the predicate design requirements, conditions and design of the selected program, frame structure described engineering practice and various concept entity, through case-based reasoning technology to generate candidate solutions to the allocation aspirin products design requirements. 3, Intelligent Design Intelligent Design is the main features : design theory, using 3D graphics software, Intelligent design software and virtual reality technology, and multimedia, hypermedia tools for product development design, Expression product ideas, describing the structure of products. In the use of mathematical theory at the same time, in consideration of the theory of systems engineering, product design technology and systems development methodologies VDI2221. developed for product design in the early development of the multimedia system software MUSE. Automatic teller machines during the design, the entire product development process as product planning development and production planning stage three, and full use of existing CAD cutting-edge technologies - virtual reality technology. 1) Product Planning-concept products. Its task is to determine the external product characteristics, such as color, shape, surface quality, ergonomics, etc., and the idea of using the initial three-dimensional CAD model shows that the establishment of products to reflect the shape of a simple model, The model can establish virtual environment, using data cap and 3D mouse, Users also to some extent involved in the environment, and can quickly generate different shapes and colors. Detection is a three-dimensional model of the effect of the external shape, as well as a design variable geometry shows that the basis for the same time the process of developing various types of analysis. 2) development-design products. According to the main stage, Synthesis System principle, a three-dimensional model of the configuration and integration solution elements, Solutions based on the design elements of the different goals have different meanings : it is the basic elements, such as bolts, or wheel shaft connected; it can also be a composite elements, such as mechanical, electrical and electronic components, control technology or software components of the drive system; It may also be requested, character, shape, and so on. To achieve functional solution of the key elements of the three-dimensional distribution model, will be the configuration of products (design model solution to the relations between elements), Product Configuration analysis is integrated product planning and development an important means of the results. 3) production planning-processing and assembling products. At this stage, mainly discusses the assembly process of CAD technology, proposed using computer image display solution elements in the corresponding location of the assembly process. through virtual assembly model reveals fashion and the relationship between the assembly, which found difficulties and problems, and find a way to solve problems, and that technology will be integrated CAD product development for the three stages, the design process can be integrated with the analysis of the product planning, development and production planning to the alternating row. Therefore, it can be found in all the earlier stages of the problems that exist so that their products in the development process of continually refined and improved. Chinas use of virtual reality technology is still in the design phase has just begun. The use of object-oriented technology, focus on the chronology of the agencies synthesis package design expert system, and with the help of high-performance graphics and the ability to handle the exchange of OpenGL technology, in 3D environment from all angles right expert system design program for observation, If inter-agency campaign convergence position of conflict, and so on.Construction of the standard modules, overall product structure and its manufacturing process and use the design (see Figure 1) as rapid prototyping technology. Recommended in the product development process will be rapid prototyping technology, multimedia technology and virtual expression and neural networks (used in various stages of the process required for the occasion) combined application. With that computer software and hardware to keep on improving. will be possible to multimedia graphics processing technology for product development, For example, 3D graphics (3D model) to replace assembly, demolition and design Connector when the three-dimensional structure of the imagination, and so on. Intelligent CAD system SIGRAPH-DESIGN as a development platform product development process is divided into conceptual design, assembly design and components design and design variables to technology as the foundation, a cam linkage Offset conceptual model. From the literature on the research work, the concept of the model is to determine the type of institutions, a number of consolidated basis, using software SIGRAPH-DESIGN design variables for the function, With the diagram so that the structure and change parameters, and the concept of model parameters passed to the assembly under one model, parts design. Network technology to flourish, Collaborative Design and Manufacturing, and the users of products from the functional requirements Design processing finished assembling the parallel project of the possible. However, to achieve these objectives by one of the important prerequisites for that product design effect of 3-D visualization. To this end, 3D graphics software, intelligent design software used in more and more products to the design, Virtual reality technology and multimedia, hypermedia tool is the design of products began to bear fruit. Currently, Germany and other developed countries are focused on research-media technology, product data exchange standards STEP, and the standard Virtual Reality Modeling Language VRML (Virtual Internet platform environment based on the standard exchange format) Product design applications. Mechanical Products programs are moving towards computer-aided design to achieve, Intelligent Design Collaborative and meet the needs of design and manufacturing direction. product design computer method of a late start, but there were no mature, to achieve the above objectives of the program design software tools. The writer believes that the integrated use of four types of text is designed to achieve this objective effective way. Although these methods are integrated use of the field more, not only with the mechanical design of the domain knowledge, but also to the theory of systems engineering, artificial intelligence, computer hardware and software engineering, Network technology and othe

温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。