表面喷丸处理对轴用42CrMo钢弯曲疲劳性能的影响

根据轴类零件的实际工况,选用缺口棒状试样作为研究对象,分析了经表面喷丸处理的调质态42CrMo钢在常温空气环境下的旋转弯曲疲劳性能。结果表明,试样经表面喷丸工艺处理后,抗弯曲疲劳性能显著提高,疲劳极限提高约90MPa;表面喷丸试样疲劳裂纹产生和扩展速度缓慢,宏观断口呈现出塑性断裂特征。     

箱体类零件的信息描述与输入系统研究

介绍了箱体类零件计算机辅助工艺设计(CAPP)关于零件信息描述及处理的一种实用方法,利用特征形面集及形面代码集对箱体类零件加工信息进行描述,并以此方法为基础,开发了箱体零件的信息描述与输入子系统,采用图形显示、菜单选择、人机对话、文字提示等方式输入零件信息,为CAPP专家系统建立了完整数据信息。     

支架类零件机械加工工艺及工装设计

随着科技的快速发展,机械制造业取得良好发展,支架类零件加工工艺和工装设计都有明显提升,提高零件应用性能。围绕支架类零件的加工工艺及设计等方面展开讨论,以提高零件操作性和稳定性为主,不断改进这类零件的加工流程,以便突出支架类零件的应用优势,为机械制造行业的发展提供动力。     

影响轴承零件保护气氛热处理光亮度的因素

在轴承行业中，已有越来越多的轴承生产厂家在轴承零件热处理过程中采用保护气氛加热，实现了光亮淬火，从而极大地提高了热处理后零件表面的质量。首先取消了原来由于在空气炉中加热产生氧化皮而必须进行的酸洗去氧化皮工序(酸洗对轴承零件表层有严重损伤，会造成疏松和引起氢脆微裂纹)；甚至可以取消热处理后的抛光工序(抛光易造成轴承零件的密封槽填塞抛光物颗粒，增大零件清洗的困难)。     

某型机高温合金盘类零件变形控制研究

高温合金薄壁盘类零件加工中残余应力的产生、释放及对零件变形的影响巨大。通过改进某型机薄壁盘类零件加工工艺路线,合理分配加工余量、优化切削参数,实现对该类零件加工变形的控制。     

数控机床加工精度超差故障分析

从机械方面分析数控机床和加工中心加工轴杆类零件及镗孔圆度类零件精度超差的原因.     

请求确认不侵犯“鳄鱼”商标权诉讼引发的思考

一、案情举要被告鳄鱼恤有限公司于1996年3月30日经我国国家商标局核准注册第246898号"CROCODILE"商标,核定使用商品为第25类裤子等,有效期至2016年3月29日。新加坡鳄鱼公司在韩国注册了以下商标:1、1987年11月19日注册0147499号"Crocodile及图"商标,有效期至2017年11月19日,指定商品为第45类长裤等;2、2005年10月5日注册     

20CrMnMo钢渗碳空冷裂纹的原因及防止措施

煤矿机械设备中的减速器齿轮、轴类零件 ,其原材料多为 2 0ＣｒＭｎＭｏ钢。但在生产过程中常常出现渗碳出炉空冷后 ,部分零件会成批开裂而报废。其裂纹分布于零件表面 ,并与轴颈垂直纵向开裂 ,甚至沿齿轮齿顶处脱落。对此开裂零件 ,我们经检验分析并提出产生开裂的原因及采取的防止措施 ,现简述如下。一、检验分析1、化学成份 (见下表 )元　素ＣＣｒＭｎＭｏＳｉＳＰ实际含量 0 2 11 2 81 10 2 5 0 2 5 0 0 3 0 0 3国标含量0 17-0 2 41 1-1 40 9-1 20 2-0 30 2-0 4≤0 0 4≤0 0 42、硬度实验(1 )　表面硬度4 7- 50ＨＲＣ(2 )…     

大型复杂框类零件加工变形原因分析及应用

运用六西格玛管理,结合精益制造流程,以操作过程为主线,分析明确大型复杂框类零件变形的关键原因。通过对关键原因的研究,提出针对性改进措施,通过实践验证,找出减小零件变形的最佳方案。最后将最佳方案规范化,形成大型复杂框类零件加工作业指导书,用于指导加工。     

石油钻井设备轴类零件损坏类型及修复方法

钻井设备常用轴类零件损坏类型与原因,钻井设备修理中尝试的几种轴类零件修复工艺,如焊补、粘胶、喷涂、镶套方法。     

引进火电机组设备备品备件的管理

备品备件是缩短检修时间重要的物质基础。引进机组在建设过程中,加强备品备件的管理还可为国家节省外汇。为此就引进电站工程在建设过程中,引进设备备品备件的分类方法、引进数量、管理的实用制度、错供漏供备品的补供以及工程峻工后备品的移交等问题进行了分析讨论。     

Reducing the mean supply delay of spare parts using lateral transshipments policies

Lateral transshipment has been studied lately as a promising policy for increasing the performances of multi-echelon spare parts inventory system. By lateral transshipment spare parts can be moved from one location with excess inventory to another location, at the same echelon, in shortage, with the aim of reducing supply delays of spare parts. This paper will examine the relative effectiveness of two lateral shipments approaches in reducing the mean supply delay (MSD) of a non-repairable item, with respect to a classical policy of no lateral shipments. A simulation model of a two echelon supply network has been implemented and an experiment has been performed by varying different parameters of the supply network, such as the number of warehouses (locations at the lower echelon), the supply lead time from the central depot, the spare parts demand uncertainty, and the size variability of the warehouses. Results show appreciable reductions of MSD when lateral shipments are allowed with respect to the classical policy, in almost every network configuration.     

电力企业备品备件储备管理模式的新思考

针对电力企业当前的备品备件管理模式下存在管理难、利用率不高和资金占用大等问题,提出备品备件的联合储备、供应商管理库存储备和联合虚拟储备等新型模式,介绍了具体的储备方式,并展望了在电力企业的应用前景。     

Stocking decisions for repairable spare parts pooling in a multi-hub system

This paper presents an analytical model for determining spare parts stocking levels in a single-item, multi-hub, multi-company, repairable inventory system in which complete pooling of stock is permitted among the hubs and companies. The objective is to minimize the total system cost which consists of inventory holding cost, downtime cost and transshipment cost. We develop an approximation method to compute the logistical system performance measures needed for calculating the cost function. To find the optimal stocking levels, a two-stage solution is proposed. In the first stage, the demands at all hubs are aggregated and treated as if occurring at a single location. The optimal number of total spare parts is determined by minimizing the sum of inventory holding cost and downtime cost. In the second stage, a heuristic procedure is developed to find the optimal allocation of the total spare parts to minimize the total transshipment cost.     

On how buyback and remanufacturing strategies affect the profitability of spare parts supply chains

The purpose of this paper is to provide a case-based framework to offer insights on the opportunity of recovering parts. We consider a two-stage spare parts supply chain, where independent repair shops are responsible for handling the repair process. There are two options to meet spare parts demand: repair shops may replace the part with a new one (ordered from the OEM) or they may use a part that they themselves repaired before. While repair shops achieve a larger profit by repairing parts, the OEM would prefer the use of new parts. However, he has no control over demand which might be obtained by offering buyback of broken parts. Furthermore, the OEM could recover these parts on a higher level, thus reducing production/procurement of new parts. The main contribution of this paper is the provision of a simple deterministic framework for answering the question whether a buyback option should be offered by the OEM to the repair shops, and which buyback price should be paid for each returned core. We further highlight the impact of remanufacturing performed at the OEM on the profitability of buyback.     

A Continuous-Time Examination of End-of-Life Parts Acquisition With Limited Customer Information

Manufacturers often encounter difficulties in supplying an adequate number of spare parts for a product that is in its post-production phase. Current solution methods for optimal spare part order amounts use assumptions that require knowledge of the number of products in operation at any time t. In the business situation presented here, the manufacturer only has knowledge of the part and product failure rates and a probability distribution on the number of products still in operation; unless the manufacturer and customer have a close working relationship, it is likely that this information is all that the manufacturer will have available in a typical business environment. We model time-discounted revenues and costs as a function of the spare parts order amount. We consider two different versions of the problem—incremental replenishment and no replenishment—that operate by determining the rate of change of the total profit with respect to the order amount q.     

The effect of design protection on price and price dispersion: Evidence from automotive spare parts

The design right is a widely used but poorly understood intellectual property right that allows the protection of products’ aesthetics and outer appearances. We study the influence of design protection on price by exploiting cross-country differences in the scope of protection in the European automotive spare parts market: In some countries, repair parts are exempted from design protection, while in others they are not. Based on detailed price data, our difference-in-differences estimates imply that design protection increases prices by about 5–8%, with large differences between carmakers. We then link our findings to the literature on deviations from the law of one price. We document large cross-country price deviations for identical spare parts and provide evidence that a part of these price deviations can be explained by the lack of harmonization of design protection in combination with carmakers’ pricing-to-market strategies.     

海外EPC项目最终结算常见问题与对策分析

在上海电气电站工程公司承建的某海外电站EPC项目中,项目提前合同完成临时移交,但却在最终结算、尾款收款时暴露出较多问题,例如,备件移交困难,当地劳工社保缴纳不及时,业主存在合同争议等,导致最终支付证书签发延期,尾款无法按期入账。针对最终结算时发现的问题,本文进行了整理和分析,并提出了针对性建议和对策,包括加强合同管理、缺陷处理,备件和资料管理、索赔以及合规性管理等。     

Inventory management in a multi-echelon spare parts supply chain

In many industrial sectors, firms are dealing with a demand which is more and more uncertain often due to the supply chain structure. One of the most critical effects of demand uncertainty is the simultaneous increase of inventories and decrease of customer service. This work describes an integrated system for managing inventories in a multi-echelon spare parts supply chain, in which customers of different size lay at the same level of the supply chain. The differences in size generate demand peaks and thus a very variable and lumpy demand pattern. The analysis presented in the paper stems from a case study in the field of durable goods spare parts. The paper contributes in three ways: on the one hand, it shows that consistency between managerial solutions and supply chain structure enables to enhance operative performances. On the other hand, it provides a new solution to a problem that characterises several different industrial contexts. Eventually, it highlights that the exploitation of a larger and more reliable set of information dramatically improves performance.     

ZGM123中速磨煤机检修优化与改造

介绍了天津大唐国际盘山发电有限责任公司磨煤机的检修优化的实践和研究,磨煤机的检修优化首先是要基于点检定修的深入开展,通过点检定修确定合理、经济的检修周期;其次是通过采用先进的工艺技术对设备进行改造,从而减少磨煤机大修时的检修工作量和备件消耗,达到检修优化。