数控车床加工中编程的原则与工艺优化技术分析

在数控加工中,不管是手工编程或者自动编程方式的应用,都需要对加工零件的零件图进行分析,对机床、夹具和刀具等进行合理选择,对数控加工的加工工艺方案合理确定。在数控编程中处理工艺问题的质量,不仅会对机床效率的发挥产生影响,零件的加工质量和生产效益也会受到影响,需要引起人们足够的重视。文章分析了数控车床加工中编程的原则与工艺优化技术,希望可以提供一些有价值的参考。     

基于HyperMill虚拟机床的建立与仿真

HyperMill自动进行干涉避让,为五轴刀路进行准确验证,进一步保证了五轴加工的安全性,避免机床干涉,刀具干涉,夹具干涉等。提出一种通过NX建模导出stl格式模型进行建立虚拟机床,实现了机床仿真模拟加工,采用HyperMill自带的HyperVIEW进行模拟仿真,大大提高了五轴加工效率。     

基于UG的变螺距螺旋槽建模及数控加工编程

文中阐述了用UG的参数公式方法进行变螺距螺旋槽零件的立体建模,并应用UG软件自动编程方法编制螺距螺旋槽零件在四轴加工中心机床上的加工程序,比较分析了各种切削参数设定和加工工艺方法运用。     

浅谈台阶轴零件机械加工工艺规程设计

台阶轴广泛应用于各类机械产品中,其加工工艺是否合理、可行等直接影响产品的质量。文章依据机械加工工艺规程的步骤,针对台阶轴零件的机械加工工艺规程进行设计,阐述了机械行业典型轴类零件的机械加工过程的前期准备工作,制定了机床、刀具、量具、毛坯等的选择及工艺路线,列出了相应的机械加工工艺过程卡片和刀具卡片。     

超长丝杠的加工综述

机床丝杠是机床上的传动部件,它将均匀的旋转运动精确地转换为均匀的直线运动.它不仅要准确地传递运动,而且还要传递一定的转矩.因此精度、刚度和耐磨性都有极高的要求.我们在工作中,经常会碰到丝杠严重磨损需要重新加工的情况,或是一些自制机床较特殊丝杠的加工.如按照常规工艺加工,工序多,流程长,需要的设备也较多;特别是加工周期长,还会影响机床的按时修复,从而影响生产.加之,如果没有较长轴的外圆磨,没有专门的螺纹加工机床,那么外协加工就会增加成本,延长生产周期.因此,对于超长丝杠,都尽可能的选择在普通车床上加工完成.在加工中,为增加工件的刚性和防止热变形,我使用了中心架、跟刀架和弹性伸缩顶尖;为减小车削时径向力的影响,防止振动,采用合理的车刀几何形状;为提高螺纹的加工效率,粗车时采用了"郭嘉明高速车削蜗杆法",缩短了粗加工时间.此加工方法比原加工方法提高生产效率30%.由于采用了正确的方法,保证了工件质量,缩短了生产周期,降低了加工成本,也为企业节约了开支.     

细长轴切削加工技术分析

车削细长轴具有大长径比,所以在切削力的影响下会存在弯曲震动、变形的问题,增大了细长轴切削加工工艺难度.通过分析细长轴切削加工过程中的夹紧方式、切削参数、误差补偿等技术研究,有助于提升细长轴切削加工技术水平,合理地运用不同切削加工方案,更好地指导细长轴加工工艺实施.     

论数控车轴类零件的工装与加工路线设计

本设计以数控车床轴类零件车削为例,根据被加工工件的材料、轮廓形状、精度等要求进行工艺分析,选用合适的机床、刀具、夹具及加工路线。     

数控机床加工工艺分析和精度分析

近年来我国的数控机床技术正处在突飞猛进地阶段,在数控机床的使用过程中,加工工艺分析和精度分析对于机床的加工效率和零件的加工精度都有重要影响,文章研究了数控加工工艺的主要步骤和精度研究中容易出现的问题以及解决方法,以期对数控机床的加工工艺研究有一定的促进作用。     

如何选择轴类零件的定位基准

轴类零件定位基准的选择是制定加工工艺的重要步骤。文章在分析典型的轴类零件的结构、技术要求的基础上,与实际的加工过程相结合分析定位基准的选择,制定合理的加工工艺。     

304不锈钢吊装门五金连接件铣削加工工艺分析

文章介绍了校企合作生产中,在加工中心机床上批量加工304不锈钢零件的工艺过程,分析和总结了不锈钢吊装门零件铣削加工工艺。     

Development in Information and Communications Technology (ICT) Statistics at the Australian Bureau of Statistics

This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field.     

Value at Risk in the Suburbs: Eminent Domain and the Geographical Politics of the US Foreclosure Crisis

Several US counties and local governments have recently considered a novel solution to the foreclosure crisis. They plan to use eminent domain to compel the owners of mortgage debt—and specifically of private‐label mortgage‐backed securities—to sell the debt to the government at a price reflecting the loan's market value. The government would then restructure the debt and resell it to new investors. The plans are striking because—in contrast to both development‐driven eminent domain and the federal subprime bank bailout—they would force investors to assume asset devaluation and increased long‐term risk. Notably, the plans have emerged as an instance of financialization‐focused politics in suburbs and suburban cities of color, specifically majority‐black and ‐Latino/a suburbs. Local support for the plans, we argue, is rooted in the long‐term disinvestment of these ‘suburbs of exception', which became targets of subprime lending and eventually sites where the ‘financial exception' has been localized. But these demographic shifts, fragmentation and fiscal pressures have at the same time created a suburban political terrain in which the plans have gained their strongest political support.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Accountability of NGOs in Bangladesh A critical overview

NGOs in Bangladesh have been recognized as effective change agents in the socio-economic arena throughout the world. Their contributions in micro credit, non-formal education and primary health care are widely known. NGOs play a significant role in society. NGO accountability, as a result, has become a critical issue. NGO accountability in Bangladesh has been examined here in relation to patrons, clients and themselves. Of the three relationships only accountability to patrons is in a near satisfactory state. Accountability to clients is handicapped by lack of opportunities of beneficiaries to participate meaningfully in NGO policy making. Accountability to themselves is adversely affected due to the adherence to a strictly hierarchical system and the influence of founding and charismatic NGO leaders.     

Towards an Asian model of human resource management? A comparative analysis of China,Japan and South Korea

There has been much discussion regarding the possible decline and weakening of national systems of human resource management (HRM). Yet, culture and institutions are often cited as the major stumbling blocks to this outcome. Such constraints may dissipate in the analysis, particularly if ‘regional clusters’ are considered where geographic and cultural closeness and ‘openness’ to similar economic pressures exist. In such cases, it might be postulated that convergence in HRM will occur. We argue that China, Japan and South Korea represent such a cluster. This article examines these countries, to see if a degree of convergence is taking place and if it is towards an identifiable ‘Asian’ model of HRM. A model of change is presented that distinguishes between levels of occurrence and acceptance. Details of the development and practice of HRM in each country are then set out. The article ends with a discussion and implications section and a brief conclusion.     

Ansätze und Ergebnisse anglo-amerikanischer M&A-Forschung

Based on a review of established U.S. management journals (1995–2003), six schools of thought are identified within the Anglo-American M&;A research: “Capital Market”, “Principal/Agent”, “Industrial Organization”, “Organizational Behavior”, “Human Resources” and “Strategic Management”. The literature review shows that the definition of M&;A success, the methods applied, and insights from empirical research differ according to the respective school of thought. Empirical studies focus on the resource combinations of merger partners, the specific circumstances of merger negotiations, and on integration management as antecedents of merger performance. Unfortunately, empirical findings have not yet provided reliable explanations for M&;A success. Based on the current state of Anglo-American M&;A research, the authors discuss implications for business practice, identify research gaps, and propose areas for future research.     

Introduction of New Technology with a Sound Transition of the Input-Output Structure

We examine the general equilibrium repercussions associated with the introduction of new technologies, using the generalized Leontief system that allows technological substitutions. We show that an untested introduction of cost-increasing technologies in any industry may result in creating a non-productive technological structure that does not satisfy the Hawkins-Simon condition, following the autonomous dynamic adjustment process with structural transitions in the economic system. Therefore, we propose a practicable control scheme of introducing cost-increasing technologies that strictly avoids the creation of non-productive structures in all periods of structural transition, using the available information on the ex ante technological structure.     

The Creation of the Office for National Statistics

A new Office for National Statistics was created in the United Kingdom in 1996 following a series of developments designed to strengthen the relevance and integrity of statistics. This paper describes these fundamental changes and sets out a blueprint for future progress. It also sets current developments in the United Kingdom in an historical and international context.     

What helps? Women engineers' accounts of staying on

We have considerable understanding of the obstacles that women engineers encounter and the reasons that they leave the field, but we know less about what enables them to remain. Adopting an interpretivist approach, this article examines how a group of British women engineers in two FTSE 100 companies account for “staying on” in their male‐dominated work settings. We delineate four specific forms of help that facilitate women's retention in the field. We argue that exposure to help leads to women developing a habitus that enables them to continue working in engineering. To conclude, we draw on our findings to outline HR practices that will facilitate supportive relationships in the workplace and pave the way towards developing more positive organisational climates.     

论现代物流企业的发展观

物流业经过诸多年的发展目前已经成为最热门的行业之一,物流企业的注册数量也与日俱增,达到前所未有的规模。毋庸置疑,任何企业都希望自己迅速做强做大,并成为真正现代物流企业的典型代表,要实现这一目标一个首要问题就是要解决现代物流企业的发展观问题。