汽车侧围开卷落料模设计

介绍了汽车整体侧围开卷落料模的设计,解决了侧围开卷落料模中存在废料滑出困难、板料撞击刃口、材料利用率低等问题,排样设计中将侧围废料用于前立柱下加强板和后地板孔盖板零件的生产,提高了板料的利用率。经生产实践验证,该模具对于类似零件的冲裁具有一定的参考作用。     

落料排样工艺的线性规划

落料排样工艺的线性规划北京经济学院工厂张之燕１线性规划简介线性规划是辅助人们进行科学管理的一种数学方法，线性规划所研究的是在线性约束条件下，使线性目标函数达到最优。例如，在工厂现有设备、人员的条件下，如何优化零件加工工艺的设计，使生产效率最高、成本最...     

基于碰撞算法的排样系统的研究与应用

提出一种用于冲裁件排样的碰撞算法。基于该算法开发了排样系统 ,自动计算零件间的碰撞距离与排放角度 ,并且提供多种排样方法     

开卷落料模在汽车冲压生产中的应用

对汽车冲压生产中开卷落料模的应用进行了阐述,重点介绍了开卷落料模应用的意义,并从开卷落料模的排样、废料槽设计原则、托料机构形式和推料器等方面进行了详细的介绍。     

孔用弹性挡圈多工位级进模设计

介绍1副用于制造孔用弹性挡圈的模具,对冲压工艺、工艺方案以及模具结构形式、排样和压力中心等作了详细分析,并设计了孔用弹性挡圈模,模具结构合理,具有一定的参考价值。     

卷料的经济利用

卷料成本取决于材料种类、厚度和表面光洁。它占冲压生产成本的30％～70％。如果材料得不到合理利用,冲压生产的成本可能更高。假如压力机行程每分钟为500次,每次产生2g废料,那么每8小时就会浪费将近半吨的材料。因此,应根据冲件的特点和质量要求,在保证模具强度和不影响压力机工作的前提下,设计少废料排样。下面例举一些能改善材料利用率和提高生产效率的方法。 1.多行排样设计排样主要是依据冲压件的形状、尺寸和复杂程度。一般,单行排样每次冲压行程只     

新型浮动切刀在落料模上的研究与应用

由于汽车覆盖件零件尺寸较大,采用传统的排样工艺设计开卷落料模会导致模具尺寸超出开卷设备的工程能力范围。通过应用浮动切刀技术改进了传统的排样方式,能有效缩减落料模尺寸,并应用材料力学知识推导出最小浮动切刀修边长度,可保证板料边缘在废料刀和切断刀连接处不发生变形,通过改善上模切刀结构,解决了上模切刀侧壁摩擦板料边缘导致板料边缘变形的问题。     

冲件排样与挡料装置的设定

介绍了冲件排样的工艺设计以及模具的挡料装置的设定 ,结合具体实例 ,对排样及冲压工艺进行优化设计     

冲压毛坯嵌套排样的一种算法

冲压毛坯嵌套排样优化问题是冲压毛坯排样优化问题中的一个难点。本文在分析了嵌套排样优化问题产生的条件之后 ,详细介绍了一种可以在各种情况下解决毛坯嵌套排样优化问题的算法 :拆分——裁剪分段平移法。同时对采用枚举法解决毛坯排样优化问题作了总结。     

人工智能技术在排样技术上的发展现状

排样问题广泛存在于加工制造业的各个方面,智能化排样技术直接影响到材料利用率的高低和工人的劳动强度,对排样问题的研究具有重要的经济意义。文中介绍了各种排样算法的基本原理、流程及优缺点。     

Der postgraduale Diplomstudiengang „Korrosionsschutztechnik”︁ an der Märkischen Fachhochschule Iserlohn

The postgraduate diploma study “Corrosion Engineering” at the Iserlohn Polytechnic A postgraduate diploma study “Corrosion Engineering” can be studied at the Märkische Fachhochschule Iserlohn (Iserlohn Polytechnic) either as a three semester full-time study or as part-time study for employed individuals with open time axis (average time three years). The modular study is composed of the courses Physical Chemistry, Material Science, Measuring Techniques, Corrosion Basics, Corrosion Protection, Failure Analysis and Special Topics. Study letters' support the selfstudy process. The contents of the moduls is worked up during 8 separate one to two weeks courses with lectures, seminars, exercises and experiments held in Iserlohn in the Laboratory for Corrosion Protection. The study which today is highly acknowledged in the industry terminates with a three months diploma thesis and will be an integral part of present concepts for certification of persons working in the field of corrosion and corrosion protection. The paper outlines in detail the structure and the contents of this diploma study.     

中药新药防治儿童功能性便秘的临床研究技术要点

基于国内、外文献并结合作者的临床科研实践,在试验目的与试验设计、受试者的选择、治疗方案、试验流程、有效性评价、安全性评价、试验的质量控制和保证等方面,总结了中药新药防治儿童功能性便秘的临床研究技术要点,以期为本病的中药新药临床试验设计提供借鉴。     

电磁成形技术理论研究进展

介绍了国内外电磁成形理论研究概况及进展,总结了研究成果和特点,讨论了电磁成形中高速率变形条件下材料成形性提高的决定因素。对电磁成形理论研究的发展趋势进行了展望。     

Study of Deformation Phenomena in TRIP/TWIP Steels by Acoustic Emission and Scanning Electron Microscopy

Modern metastable steels with TRIP/TWIP effects have a unique set of physical-mechanical properties. They combine both high-strength and high-plasticity characteristics, which is governed by processes activated during deformation, namely, twinning, the formation of stacking faults, and martensitic transformations. To study the behavior of these phenomena in CrMnNi TRIP/TWIP steels and stainless CrNiMo steel, which does not have these effects in the temperature range under study, we used the method of acoustic emission and modern methods of signal processing, including the cluster analysis of spectral-density functions. The results of this study have been compared with a detailed microstructural analysis performed with a scanning electron microscope using electron backscatter diffraction (EBSD).     

钎焊技术的最新研究进展

以代表当今国际焊接技术发展水平的2002年美国芝加哥“国际焊接展示会(Welding Show 2002)”为背景，结合最新的文献资料，介绍了当今国际钎焊领域的新技术、新方向，分析了钎焊研究的新课题。同时指出，钎焊技术的研究已经过渡到数字化、模拟化的阶段，精密控制和钎焊机理的研究越来越成为关注的焦点。     

冒口保温性能的数值模拟计算

通过数值模拟技术,采用较为可靠的前处理数据及边界条件,研究了铸件冒口在不使用保温材料和使用保温材料时不同的收缩情况,并且定量地分析了保温材料能够在多大程度上改善传统模数法所设计的工艺冒口.所得到的数据结果可对生产实际起到指导和参考作用.     

A comparative study on the spindle system equipped with synchronous and induction servo motors for heavy duty milling with highly stable torque control

In order to create a higher torque spindle system for productive milling operations, rotational speed stability against the torque disturbance has been studied with respect to the spindle mechanical design parameters, actuator types and spindle control algorithms. The study showed a remarkable difference in the spindle rotational speed stability against torque disturbance between a spindle system equipped with an induction servo motor and a permanent magnet synchronous servo motor. The results of this study have been obtained by theoretical analysis, numerical simulation and physical experiments, and the experimental study showed that the hybrid actuation spindle achieves longer tool life.     

Process modeling in machining. Part I: determination of flow stress data

In the present study, two-dimensional orthogonal slot milling experiments in conjunction with an analytical-based computer code are used to determine flow stress data as a function of the high strains, strain rates and temperatures encountered in metal cutting. The workpiece materials selected for the present study are AISI P20 mold steel (DIN 1.2330, 35CrMo4) hardened to 30 HRC, AISI H13 tool steel (DIN 1.2344, X40CrMoV51) hardened to 46 HRC and Aluminum EN AW 2007 (DIN 1725 T1: AlCuMgPb, 3.1645) cold hardened to 100 HB. The methodology of flow stress determination for metal cutting, suggested in the present study, has advantages when compared with methods such as the Hopkinson's bar technique. This paper summarizes the first part of the study, conducted to estimate process variables in machining operations. The second part of the study, summarized in a different paper, addresses the application of flow stress data for predicting forces, stresses and temperatures in machining.     

Specific energy in grinding of tungsten carbides of various grain sizes

The objective of this study is to investigate specific energy in grinding of tungsten carbides of various grain sizes. Through the construction of a mathematical model, the study demonstrates the correlation of specific energy with the grinding process parameters and the material property parameters for the tungsten carbides. The study also examines material-removal mechanisms and surface finish in grinding of such materials using scanning electron microscopy, X-ray diffractometry and energy dispersive spectrometry techniques, etc. The study concludes that specific energy is related not only to grinding process parameters, but also to the physical–mechanical properties of the workpiece material.     

微细电沉积加工技术浅析及实验研究

简要分析了微细电沉积加工的两种典型技术——磁电沉积技术和超声沉积技术,并结合中物院机械制造工艺研究所的研究设备,开展了微细电沉积的初步实验研究,在铜基底上实现了直径25μm、高300μm的微小圆柱的电沉积加工,并通过仿真分析解释了沉积样件直径小于微细电极直径的原因。