超声无损检测技术应用于液压活塞行程定位的监测

本文介绍了超声无损检测技术在液压驱动装置活塞行程定位监测中的应用。文中讨论了超声方法具体应用的方案，监测系统设计，并提出了获取完整的定位信息的技术方法。     

模糊轮廓定位——六点定位法则概念的延伸

在精密铸造或型砂铸造毛坯的机加工夹具设计中,通过灵活应用六点定位法则原理,延伸出模糊轮廓定位的夹具设计理念,以解决形状复杂易变形工件的首序装夹定位问题,可有效提高具有外形轮廓度要求工件的加工合格率.     

吊钩4×90°旋转定位的改进设计

吊钩组是起重机起升机构的1个组成部分,主要用来完成各种物料的吊运工作。常用的吊钩组的吊钩为自由旋转,因各种原因而导致物料在搬运中产生旋转。根据现场使用情况,大多数物料在搬运前后都必须码放整齐,以提高厂房的有效容积率和工作效率,而物料在搬运过程中的位置不确定性导致厂房有效容积率和工作效率降低。近年来,全国各地钢厂新建、改建、扩建项目不断增多,物料搬运的数量也越来越巨大,     

顺大势而为 新常态倒逼企业重新战略定位——陈惠仁在机床工具协会重型机床分会第六届三次理事会上的讲话

如何认识当前经济形势2014年上半年国家经济发展形势受到各方面的密切关注。7月中旬,国家统计局公布上半年经济数据,2014年上半年我国GDP同比增长7.4%,其中二季度增速好于一季度,经济总体运行平稳。回顾2014年一季度GDP增速7.4%,低于政府目标的7.5%,随后4月份的经济数据更为严峻,尤其是房地产行业新增投资和市场销售大幅下滑。这样的经济数据一度引发经济领域某种程度的震惊和恐慌,也由此形成了两派争论。一种观点认为GDP保持7.5%左右的增速符合我国当前经济发展阶段性特点,属于经济正常状态;另一种观点则认为我国经济增速在7．5％左右会很危险,政府应该采取更为积极的刺激政策,比如降息、降准,否则中国经济可能会实现“硬着陆”。     

顺大势而为,新常态倒逼企业重新进行战略定位——陈惠仁在机床工具工业协会重型机床分会第六届三次理事会上的讲话北大核心

8月7日,中国机床工具工业协会重型机床分会第六届三次理事会暨2014年年会在大连召开,中国机床工具工业协会常务副理事长兼秘书长陈惠仁参加会议并发表讲话.在机床工具行业此次结构性市场下行中,重型机床行业形势尤为严峻.未来机床工具市场将如何发展？企业该如何把握施为？陈惠仁在讲话中深入解析了当前中国经济形势走势以及新一届政府对经济宏观调控的思路,并对机床工具行业市场走势进行分析阐述,进而为行业企业未来发展提出建议.     

NEW MACHINING CONCEPT FOR MANUFACTURING MICROSTRUCTURES WITH EXCIMER LASERS

Abstract

The manufacturing of microcomponents with excimer lasers, especially for small series and batch production, is an alternative to other established micromanufacturing methods associated with etch-technology. To avoid long nonproductive times, a general and flexible machining concept is presented, which is based on the mask projection of the excimer laser beam. Beginning the process chain with the workpiece design, a developed preprocessor is able to calculate the overall removal volume from computer-aided design (CAD) data and to break down into elementary volumes that are able to be processed with single laser pulses. Moreover, based on the restrictions of the excimer laser process, a set of NC data is generated to automatically start the production process. The reliability of the system is proven with different geometries such as micro-gear wheels and microlenses.     

成形极限曲线的新概念

失稳理论是成形极限曲线（ＦＬＣ）的理论基础。本文论述了ＦＬＣ理论研究中存在的问题。研究指出：一般出厂板的表面状况不会影响板料的集中失稳；板内损伤平面应变时最严重；双拉时，板内损伤的积累、发展，导致应力状态向平面应变漂移；拉压时，载荷失稳后引起的双拉，也会导致平面应变。因此平面应变状态的出现是板料集中失稳的共同原因。在此基础上，建立了ＦＬＣ左右两半部统一的模型。新模型与试验结果符合良好，优于Ｍ－Ｋ理论。     

TIME-SPACE CONCEPT FOR PRECISION MEASUREMENT

The transformation between time and space is discussed. To improve real-time response speed of intelligent measuring system, the concept of exchanging program execution time with more circuitry is presented working in cycle mode. Displacement measuring by magnification is achieved with period measurement by magnification. To change the condition that traditional precision measurement depends on machining precision greatly, the concept of measuring space with time and theory of time-space coordinate transformation are proposed. Guided by the idea of measuring space with time, differential frequency measurement system and time grating displacement sensor are developed based on the proposed novel methods. And high-precision measurement is achieved without high-precision manufacture, which embeds the remarkable characteristics of low cost but high precision to the devices. Experiment and test results conform the validity of the proposed time-space concept.     

A NEW CONCEPT FOR DECOUPLING THE CUTTING FORCES DUE TO TOOL FLANK WEAR AND CHIP FORMATION IN HARD TURNING

Determining the temperature field in metal cutting when the tool flank is progressively worn requires the knowledge of the forces due to tool flank wear and that due to chip formation. In the past, these forces have been computed from data experimentally measured with a dynamometer, under the assumption that the chip formation configuration remained unaltered when the tool flank is progressively worn. This approach has been used in the literature even though there has been evidence that it is not correct. The error introduced by this doubtful assumption in computing the maximum surface temperature in the work-piece can be significant.

Of late there has been considerable interest in employing hard turning as the final finishing process in place of grinding and superfinishing. Consequently, the ability to accurately predict the maximum surface temperature and its distribution in the workpiece is now most desirable, for avoiding thermal damage to the machined surface. This paper discusses a new method based on the thickness of the microstructural change in chips to decouple the tool-flank forces for predicting the maximum surface temperature and its distribution in the workpiece.     

rIME.SPACE CONCEPT FOR RECISION MEASUREMENT

The transformation between time and space is discussed. To improve real-time response speed of intelligent measuring system, the concept of exchanging program execution time with more circuitry is presented working in cycle mode. Displacement measuring by magnification is achieved with period measurement by magnification. To change the condition that traditional precision measurement depends on machining precision greatly, the concept of measuring space with time and theory of time-space coordinate transformation are proposed. Guided by the idea of measuring space with time, differential frequency measurement system and time grating displacement sensor are developed based on the proposed novel methods. And high-precision measurement is achieved without high-precision manufacture, which embeds the remarkable characteristics of low cost but high precision to the devices. Experiment and test results conform the validity of the proposed time-space concept.     

产品级再使用维护设计研究

产品级再使用是废旧产品回收的第一优先级,研究了产品级再使用模式,提出产品向任务维、等级维、用户维、地域维发展或由原来用户继续使用的5种发展方式;建立了一个产品级再使用维护设计的规划模型,确定各个产品特性的维护方案,也就是目标值改进率,使所维护的产品在有限的资源约束下最大限度地满足用户需求;在模型中,用专家权重-用户概率系数法确定用户需求权重,由此配置产品特性的维护重要度系数,案例表明该模型能帮助维护人员有效地规划出最优的设计方案。     

DESIGN REUSE METHOD FOR ASSEMBLIES IN CONCEPT DESIGN

Aiming at difficult sorting and retrieving complicated structure assemblies in assembly lib, a method for compartmentalizing assembly design resource by conceptual product structure model is presented. The similar assembly retrieval mechanisms of symbol assembly relation graph matching and symbol assembly relation graph similarity are discussed. The method is validated by taking valve rod assemblies as example.     

介绍一种校准加速度计的新装置

混合摆是由单摆与复摆构成的一种新型摆。它克服了单摆与复摆各自的缺点，兼有二者的优点。本文介绍了这种摆的结构原理、性能特点和设计依据，而且阐明了其冲击加速度的计算与测试方法。这种装置避免了地球重力加速度的影响。适合于中低档ｇ值加速度计的校准工作，其准确度优于５％。     

FUZZY OPTIMIZATION MODEL OF MAINTENANCE DESIGN FOR PRODUCT LEVEL REUSE

Most used products must be maintained before they are reused. The modeling method formaintenance design of product level reuse based on quality function doployment is presented. A fuzzylinear optimization model is developed under financial uncertainty.Objective of the model is to maxi-mize improvement rate of customer satisfaction level. Maintenance cost constrain is fuazy The algo-rithm for solution to the model is given. Its optimized results not only give attention to satisfactiondegree of cost constraint, but also maximize objective value. An illustrative exmple involved waterbump reuse is Stodied and the results show that the proposed model can effectively help mainteenanceplanner determine the better design scheme.