传动箱体消失模铸造工艺中的缺陷问题

为了解决消失模铸造传动箱体中铸件结构复杂、上口处容易变形、加工量较小、工艺设计及制造难度较大、容易造成废品等问题,从铸件模型的生产过程出发,根据铸件的结构特点,分析了模型废品产生的原因,对浇注系统的设计及造型过程进行了改进研究,对铸造生产过程中存在的冷隔缺陷、水汽冷隔缺陷、铸件起包、涂料夹渣、内浇口部位夹渣、泥条夹渣、内浇口处黏砂、硬木条处黏砂等问题提出了具体的解决方案,使传动箱体的成品率稳定控制在95%以上,为传动箱体消失模铸造类似产品的生产提供了很好的借鉴依据,对消失模铸件的生产具有一定的参考价值。     

消失模在铸钢上的应用

近 1 0年来 ,消失模铸造 (ＥＸＰＥＮＤＡＢＬＥＰＡＴＴＥＲＮＣＡＳＴＩＮＧ)简称ＥＰＣ ,因其在工艺和经济上的独特优越性 ,已被越来越多的人们竞相使用于生产各种铸件。从理论上讲 ,ＥＰＣ法适用于任何材质的铸件 ,但对于铸钢件生产 ,尤其是中低碳钢铸件 ,由于浇铸时模样分解产物与钢液相互作用 ,在铸件表层产生增碳 ;工艺因素不当时 ,表层甚至可以得到近亚共晶白口铸铁组织 ,从而明显影响铸件性能。这一缺陷极大限制了消失模技术在铸钢件生产领域的应用。因此 ,通过研究铸钢件渗碳机理 ,在生产中采取不同的措施来减少碳质缺陷 ,成为当…     

灰铸铁端盖消失模铸造工艺设计及数值模拟

为了解决端盖消失模铸造过程中易产生气孔、夹渣、缩松、缩孔等问题、提高铸件合格率及工艺出品率,依据端盖铸件的工艺特点,设计了顶注、中注、底注3种浇注工艺方案。利用计算机模拟软件研究了浇注温度、负压度对消失模铸造端盖充型、凝固过程及铸件孔隙体积的影响;采用正交试验的方法研究了实施底注浇注工艺方案时浇注温度、负压度对端盖铸件孔隙体积的影响;按照优选出的浇注温度、负压度工艺参数进行生产验证。结果表明：顶注、中注浇注方案在铸件的顶部均出现了明显的缩孔,底注浇注工艺方案较好;优选出的浇注温度为1 420 ℃、负压度为0.06 MPa,采用此工艺参数时端盖铸件孔隙的缺陷体积最小,为3.005 cm³,工艺出品率为77.7%,铸件的组织和性能均满足要求。研究结果可为端盖类铸铁件消失模铸造工艺的设计提供参考依据,具有实际应用价值。     

消失模铸造干砂紧实特性的研究

本文研究了消失模铸造干砂振动紧实的规律性,设计了测定干砂紧实的实验装置,得出了干砂振动紧实与振动参数及负压的关系。     

消失模涂料概述

介绍了消失模涂料(EPC)的特点、原材料的选择、涂料的配方、制备工艺、性能及使用效果,指出耐火骨料的粒度分布对消失模铸造涂料的透气性有影响,为了得到性能优良的涂料,在配制涂料时应使用粒度集中的耐火骨料,在涂料中加入非离子型或阴离子型表面活性剂,可改善涂料的涂挂性。     

炉篦条消失模铸造工艺优化

炉篦条是冶金设备烧结机上的一个重要零件,对铸件技术要求高,工作面不允许有铸造缺陷,采用消失模铸造生产炉篦条是一种先进、高效的生产工艺。针对原消失模铸造工艺经常出现的夹渣、夹砂等问题以及铸件报废的原因,在对原工艺认真分析的基础上对炉篦条铸件铸造工艺进行了优化:改变铸件浇冒口的设计,将原来的2个冒口向铸件长度方向的中间靠近;将铸件在浇注位置方向上的工作面朝下,以保证工作面的铸造质量;从管理、工艺实施和监督检查方面进行严格控制,消除气孔,保证涂料烘干,防止涂料返潮。通过优化铸造工艺,有效提高了生产效率,降低了生产成本。批量生产也证明了优化工艺性能稳定,产品质量可靠。     

EPC铸造工艺在中小型企业中推广应用的探索

随着市场经济的发展 ,从事小批量或单件生产的中小型铸造企业已经蓬勃地发展起来 ,其市场占有份额已不容小视。这些企业由于其综合财力较低、设备简陋、工艺原始、废品率高、质量相对较差。加之单件铸造工艺的拟定往往受到生产成本的制约 ,使得这些企业的经营者们对简便易行、质量稳定、成本较低 ,并且能够满足单件生产的高新铸造技术渴求已久。近年来 ,ＥＰＣ铸造工艺日趋成熟 ,并得以跳跃式地发展。如果将此项高新铸造技术广泛地应用于中小型铸造企业中去 ,将是铸造界的一场空前的革命 ,具有十分可观的社会综合效益。本着这一宗旨 ,笔者进…     

铸造缺陷粘接修补工艺的应用

为了降低由气孔、砂眼、裂纹等造成的铸件废品率,选择AR-5耐磨胶粘剂,采用表面处理、调胶、粘接、固化、整形、试压、检验的粘接修补工艺,对铸件缺陷进行修补,经修补的储水器柱塞,使用1a多未出现问题。     

铝合金铸造壳体渗漏问题分析

某铝合金铸造壳体在使用过程中发生渗漏问题,对其进行压力试验、X射线探伤和着色渗漏检查,确定壁厚交接处存在穿透性疏松。该处为物理热节,为提高冷却速度,已在内腔增加散热片,但由于散热片较薄,易在砂芯内造成型腔狭窄,在砂型涂料工序时易产生涂料堆积,影响散热效果,导致热节处的冷却速度变慢、最后产生疏松缺陷。通过制作样块和软件仿真两种方式复现问题,验证了涂料堆积影响散热效果最终导致铸件内部产生穿透性疏松缺陷的分析结果正确。     

铸钢壳体砂型铸造工艺数值模拟及优化

为了减少壳体在砂型铸造过程中所产生的气孔、夹杂、浇不足及缩孔、缩松等缺陷,提高壳体铸件的合格率,依据壳体铸件的工艺特点,设计了3种浇注工艺方案,利用计算机模拟软件研究了浇注温度、浇注速度对砂型铸造壳体充型、凝固过程及铸件孔隙体积的影响;采用正交试验的方法研究了第3种工艺方案浇注温度、浇注速度对壳体铸件孔隙体积的影响,最后按照优选出的浇注温度、浇注速度工艺参数进行生产验证。研究结果表明：第1种和第2种工艺方案在铸件上方均出现了浇不足铸造缺陷,第3种工艺方案的缩孔、缩松缺陷体积明显减少,方案较好;优选出的工艺参数为浇注温度1 560 ℃,浇注速度1.6 m/s,工艺参数下壳体铸件孔隙体积最小,为1.416 cm³,铸件合格率为96%,并且铸件的组织和性能均满足要求。所提第3种方案可缩短试制周期,降低生产成本,提高经济效益,研究可为壳体类铸钢件砂型铸造工艺的设计提供参考依据。     

平面曲柄滑块(摇杆)机构图解法设计新思路

提出了一种图解法的新思路 ,设计平面曲柄滑块 (摇杆 )机构 ,解决了传统图解法设计中量算结合的问题 ,可直接作图求得曲柄和连杆长度 ,作图简便 ,设计思路清晰 ,简化了设计过程 ,而在图解法设计过程中 ,也能加深理解曲柄滑块 (摇杆 )机构的极位特性。     

铬黑T（EBT）失效分析

针对铬黑T（EBT）在使用中发生终点显色异常,影响测量结果准确率的现状,运用可靠性技术对EBT失效进行原因分析。通过分析失效原因,提出针对性措施并实施;在已有国家标准和行业标准配置的基础上,摒弃显色不灵敏、用量大的盐酸羟胺为介质的配置方式：进一步明确国家标准和行业标准中尚无使用有效期限的固体指示剂和三乙醇胺为介质的液体指示液;调整介质配比、明确加入量及贮存条件等。通过改进措施验证,铬黑T（EBT）终点显色失效问题已解决,达到提高铬黑T（EBT）使用可靠性的目的。     

跨组织系统(IOS)在供应链中的应用模式

21世纪的竞争将不再主要是企业与企业之间的竞争。而主要是以IOS等驱动的供应链与供应链之间的竞争。企业需要和供应链上的其他企业联合起来。才有可能赢得广泛的技术、在质量和可靠性方面的快速反应能力以及持续的成本优势。有鉴于此，本文以供应链上企业之间的关系管理为基础．构建了一个IOS在供应链中应用的四阶段模式，并以此为框架，从IOS的设计、建立、应用和受益的过程来分析其因果关系，探讨影响IOS成功的关键变量和相应措施。我们认为。未来IOS将专注于核心竞争力联盟的建立和在联盟中有效地运用竞争力外取策略。     

构筑品牌战略提升我国中小型企业的核心竞争力

中小型企业是国民经济的重要组成部分,对经济发展和社会稳定起着举足轻重的促进作用。中小企业的核心竞争力是企业发展的根本保证。构筑中小企业品牌战略,对强化我国中小企业核心竞争力、扩大市场份额、保持竞争优势具有重大的现实意义。     

吉林省人均GDP(1970-2005)时间序列模型的建立

时间序列模型是按照时间顺序取得的一系列数据。本文综合运用判别时间序列平稳性的方法,建立吉林省人均GDP的时间序列模型。在判别差分序列的平稳性之后,利用自相关和偏自相关图判别时间序列模型的自回归阶数(AR(P))和移动平均阶数(MA(q));然后利用SAS软件用CLS对时间序列模型的回归参数进行估计和显著性检验,并对通过检验的回归结果进行分析。     

三坐标测量机测量螺纹量规误差来源分析

研究了三坐标测量机测量螺纹量规时误差的来源,重点分析了机械误差、环境误差、测头探测误差、软件算法误差、测量方法误差等。通过分析阐述了在测量螺纹量规时中如何减少相关误差,从而使测量数据更为准确。     

The establishment of industrial branding through dyadic logistics partnership success (LPS): The case of the Malaysian automotive and logistics industry

Logistics partnerships across dyadic and triadic relationship networks have been the basis of extensive research in the extant literature. It is well understood that competitive advantage within logistics and distribution and within supply chains are driven by value-adding aspects of not only the core competencies of each tier in the network, but also via tangential supporting factors. It is also well understood that there is a strong relationship between logistics and distribution and marketing functions, particularly in product-based organisations. In addition to deepening our understanding of how successful partnerships throughout the source–make–deliver continuum can be optimised, this research also seeks to identify how a supporting element in terms of industrial branding and marketing can lead to relational sustainability. Hence, this paper outlines the relationship between logistics partnership success (LPS) factors and the inherent link to industrial branding establishment and business sustainability within the Malaysian automotive industry (specifically, car manufacturers). Adopting a multiple case study approach, findings suggest that there is a strong association between logistics service performance (LSP) provided by the third party logistics provider (TPLP) and the development and support of a mutual brand image for both the TPLP and the car manufacturer. We contribute to the extant literature on logistics partnership and industrial branding through linking LSP with the creation and maintenance of an industrial branding strategy for both parties in the context of the Malaysian automotive industry.     

Three generations of Telework: New ICTs and the (R)evolution from Home Office to Virtual Office

‘New ICTs’, such as smartphones and tablet computers, have revolutionised work and life in the 21st Century. Crucial to this development is the detachment of work from traditional office spaces. Today's office work is often supported by Internet connections, and thus can be done from anywhere at any time. Research on detachment of work from the employer's premises actually dates back to the previous century. In the 1970s and 1980s, Jack Nilles and Allan Toffler predicted that work of the future would be relocated into or nearby employees’ homes with the help of technology, called ‘Telework’. Analysing technological advancements—the enabling forces of change in this context—over four decades sheds new light on this term: they have fostered the evolution of Telework in distinct stages or ‘generations’. Today's various location‐independent, technology‐enabled new ways of working are all part of the same revolution in the inter‐relationship between paid work and personal life.     

Disrupted work: home‐based teleworking (HbTW) in the aftermath of a natural disaster

Natural disasters disrupt the nature of work, promoting an urgent review of where work is performed. Home‐based telework (HbTW), a common form of telework, is increasingly promoted as a means to ensure continuity of operations in an emergency situation. While widely advocated, little is known of the challenges and outcomes of HbTW when employed in disaster situations. This article explores the organisational and employee experiences of HbTW in the aftermath of a disaster, drawing on data from over 240 public sector workers and their managers who worked from home following a series of earthquakes in Christchurch, New Zealand. Findings point to critical factors shaping the experiences and outcomes of HbTW in disaster situations. Significant variation in the experiences and perceptions of HbTW for team leaders highlights their pivotal role and heightened pressures to maintain control in complex disaster situations.     

Using ‘Electronic Portfolios’ to Challenge Current Orthodoxies in the Presentation of an Initial Teacher Training Design and Technology Activity

The paper examines the extent to which a University undergraduate curriculum initiative provided initial teacher trainees with opportunities to challenge orthodox design methodologies through the production of an electronic portfolio within and extended design and technology activity. It was found that the ‘electronic portfolio’ served primarily as a developmental tool for promoting creative continuity and sound, reflective, design practice within a structured educational design challenge. The portfolio also provided a focus for the development of ‘e’ learning skills as it facilitated the use of new technologies in the compilation of the portfolio. Additionally, the portfolio provided trainees with a means by which they were able to demonstrate their capability to prospective employers. The use of the ‘electronic portfolio’ challenges current orthodoxy and methods routinely employed to present and assess trainees’ creative work, which have been shown to constrain innovative practice. The paper concludes that the use of the ‘electronic’ portfolio was successful in facilitating trainees’ engagement with a creative Design and Technology process.