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。     

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,     

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.     

工艺质量的一个新的评定概念——工艺特征参数

在结构分析中,往往发生数值计算结果与实测数据差别较大而使两者不能互相验证的现象。本文则是积极利用这一差别,提出工艺特征参数概念,并以简便手段求出该参数。该参数不仅能反映结构的某些安全性能,而且能对以往难以处理的因素（如焊接,冷加工,配合）在安全方面所产生的影响,作一个综合性的度量。它可以作为评判综合工艺质量的一个重要参数,在理论与工程应用上都有一定的意义。     

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.     

切削振动中切痕形成的新机理

金属切削振动中现行的切痕形成机理把切痕看成是刀具——工件之间相对振动的简单再现,按照这种机理来分析机床——刀具——工件系统的动态特征往往使研究工作者陷入错误的结论或引起混乱。本文指出由于刀具付切削刃对工件表面前几转形成的切痕进行重复切削,切痕形成的机理比现行的简单再现机理复杂,因而提出一种新的概念来阐明切痕形成的机理可以为解决切削振动中某些关键问题提供正确的途径。     

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.     

A DECISIONAL MODEL FOR ESTIMATING RELIABILITY CURVE AND MAINTENANCE INTERVALS OF INSTRUMENTATION

Instrumentation is calibrated at appropriate intervals according to specific maintenance schedules. Metrologists have to deal with this important issue. In this report, a decision-based approach is proposed to improve the choice of calibration intervals. The reliability curve of the tested instrument is estimated to maintain control of its performance. Consequently, the next calibration is scheduled in order to guarantee reliability. The reported model provides metrologists with a procedure to establish optimal maintenance intervals in compliance with current standards. The model is based on general hypotheses, and therefore it is applicable for maintenance of any measurement system.     

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.