电磁继电器磁性零部件矫顽力自动测量方法

电磁继电器铁芯磁性零部件的主要材料是电工纯铁、铁镍合金、低碳钢及其它的软磁材料。矫顽力Hc影响到继电器吸合及释放时间。本文讨论了形状复杂零部件矫顽力的测量方法。其各项技术指标均达到国家标准和IEC标准，解决了零部件矫顽力无法检测的难题。尤其振动线圈传感器设计独特，为该检测方法起到了重要作用。该检测方法是工业在线快速检测行之有效的测量方法。     

A possibilistic approach for designing hybrid cellular manufacturing systems

In this paper, a hybrid cellular manufacturing (HCM) system is presented in which the main sources of uncertainty, e.g. the demands of parts and unit costs are treated as fuzzy numbers in the form of possibilistic distributions. The basic concept of HCM is that high variation in demand might disturb cell efficiency, so forming cells with only those parts that have stable demand, will profit. Thus, to design stable and robust manufacturing cells, a two-phase method is proposed in which a fuzzy adaptive ranking method is first applied to identify those parts with low and non-repetitive demands (i.e. the special parts) which will then be assigned to a functional cell. Afterwards, an interactive possibilistic programming model is applied to cell formation of remaining regular parts while considering both part sequences and multiple routes. To show the capability and usefulness of the proposed method, an illustrative example is also provided. Finally, concluding remarks are reported.     

维修备件基于AHP的ABC分类模型

针对ABC分类在设备维修备件管理中不足以区分重点备件的缺陷,将层次分析法与ABC分类相结合应用于设备维修备件的分类。将维修备件的易得性、关键性和经济性作为分类准则,通过ABC分类来求解备件对分类准则的权重,然后运用层次分析法计算备件的组合权重,再根据组合权重对备件进行ABC分类。该方法用于设备维修备件的分类可以快速有效地找出重点备件．提高备件管理工作的针对性和有效性。     

基于Excel的强大功能在Solid Edge中实现曲线零件的精确建模

研究了复杂曲线零件的精确建模，在研究非圆曲线插值算法理论的基础上，利用Excel的数据处理功能，对函数进行误差处理插值计算，在Solid Edge环境中使用Excel创建点曲线的方法进行曲线零件的精确建模，探索出了一种Excel与Solid Edge的完美结合方法，通过凸轮零件精确建模的实际案例，示出了曲线零件建模的整个过程，给出了这种方法在分段曲线中的具体应用。     

A new grouping method to minimize surplus parts in selective assembly for complex assemblies

Selective assembly is the method of obtaining high precision assemblies from relatively low precision components. The mating parts are manufactured with wide tolerances. The mating part population is then partitioned to form selective groups. The corresponding selective groups are then assembled interchangeably. The mating parts are manufactured in different processes and in different machines. The standard deviation of the mating parts will be different. The probability of the number of parts in the selective group cannot be the same. A large number of surplus parts is expected according to the difference in standard deviations of the mating parts. In this paper, a complex assembly with three mating parts (as in a ball bearing: an inner race, ball and outer race) is considered for analysis. A new method is proposed for partitioning the lots to form selective groups. By this method, the number of surplus parts is reduced to a large extent. The variation in clearance is minimized and the total number of groups is also less when compared with traditional methods.     

三坐标扫描数据的规律与快速图形化

扫描测量功能是三坐标测量机一项重要功能，扫描测量方法效率高，可以反映出零件表面自由形状的细部特征，因此，该方法多用于具有复杂型面零件的测量和逆向工程。由于不同型号三坐标测量机的扫描数据格式都不相同，如何识别不同的扫描数据格式，并将其转换为CAD曲线或曲面，以便进一步进行数据分析或建立三维模型，是亟待解决的问题。针对此问题自主开发的CAD接口，可自动识别三种以上数据文件格式，且效率很高。     

一种利用S参数测量平衡RFID标签天线阻抗的优化方法

针对测量平衡RFID标签天线阻抗的准确性问题,提出了一种利用s参数测量的优化方法。该方法将平衡RFID标签天线等效为双端口网络,通过联合使用端口短路、开路延伸方法测量S参数,根据拐点选取最邻近数据并进行区间的数据拟合,从而计算出天线阻抗。首先 h1 进行了测量理论分析．然后设计了实物测量场景（915MHz频段的RFID天线）,并将该优化方法与传统的Bahm方法、无延伸单端口方法、延伸单端口方法进行了对比。结果表明,在工作频段内,该优化方法所测的标签天线的阻抗实部,虚部与仿真结果基本一致,比传统的Balun2及单端口等测摄方法准确;在工作频段外,所测阻抗实部仍然与仿真结果接近,尽管阻抗虚部与仿真结果存在一定的偏差。     

Expansion of group technology to handle logical operations

Group technology is silent on logical operators; it only handles and operators. Here we expand the meaning of the incidence matrix to include logical or operators and show how to use an existing sorting algorithm. Two solutions are suggested for producing the closeness matrices, the starting point of the method developed elsewhere for sorting machines into machine cells and parts into parts families; of these, the second method is recommended for implementation, and this method is shown to be amenable to implementation in multi-dimensional cases, where categories beyond machines and parts can be sorted simultaneously. Thus, the capability of handling a broader spectrum of realistic situations is enhanced, making group technology a more important tool in planning production flow and layout in a modern factory.     

基于GIOWA算子的备件服务绩效评价方法

当前对服务绩效的研究更多的是对服务质量的衡量,但缺少从顾客感知的角度对服务业务的评价研究。同时,由于不同产品备件服务的属性重要性随着服务类型等因素的不同而有较大的差距,很难赋予服务属性固定的权重值。因此,为了全面分析备件服务绩效的影响因素,参考SERVQUAL模型建立了备件服务绩效评价体系。为了从顾客感知的角度对服务业务进行评价,采用GIOWA算子的方法以有效地融合评价体系中的多组模糊和不确定的客户评价信息。实例结果表明,该方法取得了对模糊语言评价的良好集结效果,为备件服务绩效评价提供了一种定性和定量相结合的评价方法。     

塑件翘曲度及其计算方法

参考其它行业中翘曲度的应用,引入了评价注塑制品翘曲变形的翘曲度概念。随后对特征尺寸上的翘曲度、平面上特征的翘曲度进行了详细的阐述,并在构建注塑CAE翘曲变形模拟结果的数据结构基础上,提出了基于注塑CAE翘曲变形模拟结果的翘曲度计算方法。用一实例说明了用平面特征上的翘曲度评价翘曲变形的有效性。     

一种四角钢组合约束型防屈曲支撑外围连接的设计方法研究:数值分析

与传统外围整体式防屈曲支撑不同的是, 装配式组合防屈曲支撑的外围构件由多个组件通过连接件拼装而成, 故外围连接的设计方法是此类防屈曲支撑构件设计理论的重要组成部分。针对一种四角钢组合约束型防屈曲支撑, 已有适用于单向弯曲状态的外围连接螺栓内力的简化计算方法。但上述方法的适用性尚需经过精细有限元数值分析加以验证, 并需进行适当修正, 使其具有足够的计算精度, 这是该文进行的研究工作之一。另外, 由于内核构件与外围构件之间间隙的存在, 防屈曲支撑构件更为常见的变形模式表现为双向弯曲变形, 所以该文还将在单向弯曲状态所得到的螺栓内力计算公式的基础上进行进一步的组合, 得到双向弯曲状态下的螺栓内力计算公式。该文最终给出了适用于四角钢组合约束型防屈曲支撑的外围螺栓连接的完整设计方法。     

Design of part family robust-to-production plan variations based on quantitative manufacturability evaluation

This paper presents a systematic method for designing part families whose production costs are insensitive to changes in production plans due to market demand fluctuations. A unified feature-based representation of functional geometry and manufacturability has been developed to manipulate and evaluate part designs. Based on this information and production plans for multiple periods, an optimization-based method provides alternative part designs. The manufacturability of the part designs is quantitatively estimated by the facility cost of the manufacturing system best configured for a given part family and the average cycle time estimated by the discrete event simulation of production scenarios. Redesign suggestions are made on datum definitions of the original parts. Two case studies of a family of prismatic parts and that of turned parts are given to demonstrate the effectiveness of the proposed method. Electronic Publication     

基于安全库存策略的提高订单及时率方法研究

电脑供应链中的各种不确定因素使得非核心零部件中间商经常需要依靠大量备货或加急生产来满足客户需求。而当非核心零部件中间商不愿为此备货时,交货延迟的发生比例不可避免地会较高。针对此问题,本文提出了一种基于安全库存策略的提高订单及时率减少交货延迟的方法。此方法首先对电脑生产商的需求量进行估计,在综合考虑影响订单及时率的各类确定性和随机性因素的条件下,推导得到最优安全库存因子;然后,根据电脑生产商需求估计量与安全库存因子,计算出安全库存,如果电脑生产商需求量小于安全库存量,则使用安全库存直接交货,否则,向供应商追加订货后一并交货;最后,给出了该方法的年平均库存衡量公式。实证计算结果表明,与传统的面向订单生产方法(MTO)相比,本文方法可以使电脑零部件中间商的库存周转速度加快5~6倍,单位库存持有成本降至原来的14%,订单交货准时率提升至80%左右。     

基于浓度特征向量的目标识别与分类

提出了一种新的基于零件浓度特征向量的目标识别与分类技术,以及由零件图像特征信息所构成的浓度特征信息的合理性验证方法。该技术不仅能够准确地反映目标图像的局部结构特征与整体结构特征之间的关系,而且较好地解决了计算机描述零件图像的特征信息的负担过重问题。实验表明,该技术具有识别准确、计算机负担小的优点。     

The Comparative Appraisal of Quality Characteristics of Holes after Different Finishing Methods

Magnetic abrasive machining (MAM) of internal surfaces is a less studied process than machining of external surfaces. The present study contains MAM principles of round internal parts. The finishing method MAM forms optimum physical-mechanical properties of surface layer parts which are most relative to operation. The article contains comparative data of quality characteristics of parts from steel 45 and 12X2H4A after grinding, honing and MAM. It states the peculiarities of roughness formation of surface and its physical-mechanical characteristics after mentioning finishing methods.     

Measurement and characterization of porosity in aluminium selective laser melting parts using X-ray CT

ABSTRACT

Selective laser melting (SLM) is an additive manufacturing technique which has the capability to produce complex metal parts with almost 100% density and good mechanical properties. Despite the potential benefits of SLM technology, there are technical challenges relating to the qualification and certification of the manufactured parts that limits its application in safety-critical industries, such as aerospace. Material porosity in SLM parts is detrimental for aerospace applications since it compromises structural integrity and could result in premature structural failure of parts. This paper describes the application of the non-destructive X-ray computed tomography (XCT) method to characterize the internal structure to enhance the understanding of the process parameters on material porosity and thus provide quality control of the SLM AlSi10Mg parts. An efficient and reliable XCT image processing procedure that involves image enhancement and ring artefact removal prior to image segmentation is presented. The obtained porosity level is compared with the conventional Archimedes method, showing good agreement. The characteristics of pores, such as shapes and sizes, are also discussed.     

Identification of the influential parts in a complex mechanical product from a reliability perspective using complex network theory

Due to the difference in the numbers and strengths of physical relationships among parts, complex mechanical products (CMPs) have community structure characteristics. There are often some influential parts in the community. Failures of these influential parts spread rapidly along the physical relationships between parts in the community, which seriously affects the reliability of a product. Therefore, identifying the influential parts in the community and adopting targeted measures can effectively improve the reliability and service life of a product. However, identifying the influential parts within each community in a collection of parts with complex relationships is very difficult. Thus, from the perspective of reliability, a method for identifying the influential parts of a CMP based on complex network theory is proposed and used to identify the influential parts in each community of products. First, weighted complex network (WCN) theory is employed to construct a CMP into a WCN model. Second, the complex network community detection method is employed to detect the community structure of the WCN model. Third, a modified LocalRank algorithm is employed to identify the influential nodes in each community, ie, the influential parts in each community of a CMP. Fourth, a modified susceptible-infectious-recovered (SIR) model is employed to evaluate the impacts of the influential parts. An analysis of a company's DC drill planetary gearbox shows that the proposed method is accurate and effective.     

基于模具预先补偿法的大幅面CFRP制件形状精度控制方法

针对控制大幅面CFRP制件成型后的形状精度这一关键技术问题,在剪切层法预测变形的基础上提出了一种改进的剪切层变形模拟方法。改进的方法只需少量制件实验数据,通过计算应变曲线曲率确定剪切层厚度,进而较准确地预测了CFRP制件的翘曲变形。基于变形模拟方法建立了一种大幅面CFRP制件形状精度控制方法,这一方法通过将模拟获得的变形不断补偿于初始模具型面来降低最终制件的变形。通过与实验数据的对比,证明了采用控制方法可以有效提高成型制件的精度,降低变形。     

Voltage-Ratio Measurement with a Precision of Parts in 109 and Performance of Inductive Voltage Dividers

The causes of error in inductive voltage dividers are examined in detail, and equations are developed from which the voltage ratios may be predicted with an uncertainty not exceeding 1 part in 108. Experimental methods for measurement of the voltage ratios to an accuracy of 2 parts in 109 of the input voltage vector are fully described, together with techniques by which the constituent parts of the overall error may be isolated. An improved method of winding decade inductive dividers is also described and specifications are given for multidecade devices in which the errors predictably will not exceed 1 part in 108 at 400 Hz or 5 parts in 108 over the whole frequency range 40 to 1592 Hz.     

基于结构相似性的轴类零件加工特征可拓关联方法

在现有轴类零件相似性检索方法的基础上,将轴类零件的信息模型划分为结构特征层和加工工艺层,并利用可拓基元方法进行形式化描述.提出从轴类零件结构和加工工艺两方面进行相似性检索的方法:首先基于结构矩阵表达方法,对轴类零件的结构特征进行相似性检索,从实例库中检索出2~5个相似实例,然后以可拓综合关联函数进行加工特征的相似度匹配,得出与新零件最相似的零件.通过实例验证,该方法具有可行性,并且可在检索过程中动态调整系数水平,具有检索适应性强的优点.