蹄式制动器的修理

汽车及其他建筑机械制动系的技术状况是否良好,直接关系到行车安全和运输效率。跑的快与停的住是矛盾的统一体。十分明显,行驶的安全性,与制动系的可靠性密切相关。而汽车及其他建筑机械的制动装置由于行驶中使用频繁,零件磨损机会多,尤其是摩擦片;同时,要求制动效能绝对可靠。因此,如何加强其制动系的维修,就显得十分重要了。汽车及其他建筑机械的制动系,包括手制动器与脚制动器,即停车制动器和行车制动器;前者结构简单使用率低,而后者使用频繁。本文着重讨论行车制动中的蹄式制动器的修理。蹄     

杠杆施力蹄式制动器的计算

挖掘机,起重机等回转机构中,广泛采用杠杆施力蹄式制动器。在设计与使用调整中,对如何选择施于杠杆的外力,以获得理想的制动性能尚缺少理论根据。本文依其结构,应用磨损原理,对这种制动器的计算方法作一些探讨。     

蹄式制动器双向式间隙自调装置

双向式间隙自调装置能使制动器始终保持在最佳间隙下运动，不会发生“自刹”现象，调整性能较理想，是一种新型的间隙自调装置。本文介绍这种装置的结构，工作原理和结构特点。     

凸轮作用内张蹄式制动器摩擦片等比压设计

内张蹄式制动器在各种车辆和工程机械中广泛应用.但原有蹄式制动器摩擦片比压不相等,摩损不均匀,摩擦材料利用不充分,而且磨损较快。本文提出摩擦片等比压设计原则,导出了相应的设计计算公式。并用实例证明,等比压设计与原有设计相比,节省摩擦材料22%;按同一许用比压条件,制动力矩提高37％;对于实现相同的制动力矩,摩擦片最大比压降低27%。     

基于ANSYS/Workbench的蹄式制动器接触压力分析及优化

通过分析单自由度蹄式制动器制动时的受力情况,考虑制动鼓和摩擦片之间的接触,利用ANSYS/Workbench软件创建二者之间的摩擦接触关系,通过模拟制动器的制动过程测试摩擦片的接触压力,并将得到的压力分布规律与理论规律进行对比分析,进而优化制动器的摩擦片起始角,获得更好的制动性能.     

间隙单元在多片盘式制动器设计计算中的应用

考虑多片盘式制动器多构层、有间隙的结构特点，本文利用间隙单元建立了多片盘式制动妆始压力分布的有限元分析模型，并对计算结果进行了理论分析。     

法国Poclain公司S马达制动器使用维修应注意的问题

法国Ｐｏｃｌａｉｎ公司Ｓ马达制动器使用维修应注意的问题洛阳建筑机械厂王作海法国Ｐｏｃｌａｉｎ公司生产的“Ｓ”系列低速大扭矩内曲线马达，由于有其独特的优点而被世界上许多压路机厂商采用。如西德Ｂｏｍｏｇ公司、瑞典ＤｙｎａＰａｃ公司、美国ＣＡＴ公司及洛阳建...     

湿式全盘式制动器设计计算

由于全液压盘式制动系统具有操作力轻、蓄能时间短、无水分冰结和锈蚀、结构紧凑、免维护调整、可靠性高等优点,将越来越多地应用于轮式装载机的制动系统设计中。本文介绍此系统的制动器设计计算方法和步骤。     

性能卓越的新型CAT油冷多片盘式制动器

本文阐述了极受用户欢迎的新型CAT油冷多片盘式制动器的结构性能特点。并评价了国产机型制动器的不足。     

浅议工程机械维修的安全作业

通过对国内外资料的分析，指出重视工程机械维修安全作业的重要性，分析了引起维修事故的原因，提出预防维修事故的对策。     

A multi-criteria decision analysis method for regulatory evaluation of electricity distribution service quality

This study aims to evaluate the performance of electricity distribution utilities with the use of a single global index based on a Multi-Criteria Decision Analysis (MCDA) method. The proposed approach allows the ranking of service quality according to three dimensions: supply continuity, voltage conformity and customer satisfaction. The challenge of aggregating various indicators into a single global index was overcome with the Analytic Hierarchy Process (AHP) and Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) methods. This ranking facilitates regulatory assessment of the distributors' performance, and thus improves the quality of services offered by utilities.     

Assessing the service quality of building maintenance providers: mechanical and engineering services

This study investigates the service quality in the maintenance of mechanical and engineering services. The determinants of service quality are identified and their means of evaluation are examined. A method of assessment is devised based on the SERVQUAL approach, and its use is then illustrated using a small empirical survey of clients and service providers and the ‘Gap’ model used to quantify the relationships between customer satisfaction, expected service, perceived service and service quality gap.     

房地产开发项目施工阶段的成本控制

房地产开发项目施工阶段的成本控制是项目成本全过程控制中极其重要的一个环节和阶段,它与设计阶段的成本控制一起构成房地产开发项目成本控制的两个关键阶段。本文针对施工阶段成本控制的重点内容及控制方法进行探讨及分析。     

探析施工图审查的过程控制和体会

施工图审查含政策性与技术性审查。按政府有关文件与设计规范,做好工作流程各环节的过程质量控制,抓住合同评审、收件、人力资源配置、意见记录单、修改与复审、出件与归档、重大变更等管理点,总结提高,防止类似问题的再发生,建立有效的质保体系,以"品质"与"服务"为主线,及时交付合格的施工图审查成品。     

A process approach in measuring quality costs of construction projects: model development

One of the most effective tools for evaluating the success of a quality management programme is the measurement of quality costs (prevention, appraisal and failure costs). The application of the concept of quality costs originated in the manufacturing industry in the early 1950s. As increasing attention has been given to improving the overall quality in the construction process since the early 1980s, the application of total quality management (TQM) practices in the construction industry has gained much popularity. A systematic approach is needed for measuring quality costs, especially in the construction industry, due to the great number and complexity of activities involved in a typical project. This paper describes how a simple methodology can be used to capture quality costs in construction projects. Pre-existing models for capturing construction quality costs, by Davis, by Abdul-Rahman, by Low and Yeo and by others, recognize quality cost components but do not address the causes or sources of unwanted deviations. This paper proposes an alternative approach, based on the process cost model and in conformance with BS6143 (1992), which is thought to better facilitate the fundamental goal of TQM, i.e. continual process improvement. A number of professionals involved in construction quality management were interviewed and responded favourably to the practicality of the proposed framework in the construction context.     

Exploring the emergence of lock-in in large-scale projects: A process view

The purpose of this paper is to investigate the emergence of lock-in in large-scale projects. Although large-scale projects have been studied for decades, most studies have applied economic or psychological perspectives to emphasize decision-making processes at the project front-end. Of those studies, some have focused on poor decision-making due to lock-in and the escalating commitments of decision-makers to ineffective courses of action. However, little is known about the way that project decisions are affected by organizational and inter-organizational contexts and the actors involved. Understanding decisions from a process viewpoint with a long-term (inter-) organizational perspective will lead to a better understanding of lock-in and the overall performance of large-scale projects. This qualitative research is based on a case study. The research setting is the multi-actor Madrid–Barcelona High-Speed rail Line (HSL) project in Spain. Through observations, interviews, several project documents, and report analysis, we explore the processual nature of the choices made during the course of the project. We consider the contextual conditions that give rise or support the emergence of lock-in in relation to pre- and post-project effects, institutional influences, and management practices that create action spaces at the project level. Our findings suggest that lock-in emergence requires the recognition of the long-term (inter-) organizational perspective regarding mechanisms and effects rather than confining decisions to the individual or single actor control in the front-end of projects. Based on organizational theory, the main contribution of this paper is to enrich our understanding of the emergence of lock-in using process theories.     

面向创新2.0的城管地图公共服务平台的研究与实现

应对创新2.0时代城市管理的机遇和挑战,以建立城市管理的长效机制和手段为目标,构建面向创新2.0的城管地图公共服务平台。平台以多渠道服务为牵引,对公共服务平台的业务流程进行了设计,提出了平台的总体框架,分析了以市民城管通为代表的移动技术、LBS应用,以新浪微博为代表的SNS应用等平台关键技术及其实现方法。实践表明,以创新2.0为理念,以城管地图为载体构建的社会协同共建、共享、共治的公共服务开放平台和开放数据建设,是依托现代信息通信技术创新社会管理、迈向政府2.0的重要探索。     

一种基于多项式拟合法的新的单频周跳探测方法

多项式拟合法由于其算法简单,适合于计算机运算而在周跳探测中被广泛采用。但其探测周跳的能力受载波相位观测值的观测误差和采样率的较大限制,探测小周跳的能力比较弱,常常结合其它方法进行。本文提出了一种结合广义延拓插值法和多项式拟合法进行周跳探测的新方法,介绍了其数学原理和模型,并给出了具体实施步骤,最后用算例验证了方法的可靠...     

国土资源科学数据共享平台的框架研究与设计

针对国土资源科学数据领域数据资源丰富但分布广泛的特点,设计国土资源科学数据共享平台,从整体结构和技术支撑方面阐述了平台的建设情况,整体结构体现了平台的整体建设思想,技术方面将XML,Web Service,WebGIS等现代技术运用于平台建设,起到了支撑作用。