Delayed fracture in cold blanking of ultra-high strength steel sheets

Hydrogen-induced delayed fracture at cold-blanked edges of 1–1.5 GPa ultra-high strength steel sheets was investigated. The blanked edges undergo large shear deformation and tensile residual stress, and thus the risk of delayed fracture is high, especially for the 1.5 GPa sheet. The effects of residual stress, surface quality and hardness of the sheared edge on the occurrence of delayed cracking were examined. Delayed cracking was caused by press blanking, whereas no cracking occurred for laser blanking because of compressive residual stress. For the 1.5 GPa sheet, delayed cracking was prevented by heating above 250 °C and a stain above 0.005.     

基于Pro/E的液晶显示器支架的冲压工艺与模具设计

分析了液晶显示器支架零件的冲压成形工艺,介绍了液晶显示器支架的冲裁设计,确定该钣金工件的生产工序及工艺方案,同时还介绍了多工位级进模总体结构设计、排样方案和成形特点,关键部件的设计与计算方法,模具生产的零件符合精度要求.     

基于智能决策支持技术的冲模设计系统研究与实现

将智能决策支持技术应用于冲模CAD系统中,提出了智能决策支持下的冲压工艺及模具结构设计系统的设计模式,探索了集成工程环境的冲模设计智能决策支持技术的应用方法,建立了冲模设计智能决策支持系统的框架,并研究了冲模设计知识表示、集成和决策知识系统方案评判、设计接口等关键技术的实现,给出了在I-DEAS三维设计平台上的应用实例.     

基于整体理念的吉林市民剧场城市设计

该文以吉林世纪广场新建市民剧场的城市设计为例,系统分析了整体设计的理念、方法及其应用,提出了在既有城市环境条件下具有针对性的环境嵌入、新旧对话和建筑消隐三个城市设计方法。     

用于步进电机驱动器的单稳态触发器设计

针对两相双极型步进电机驱动器,设计了一款单稳态触发器,实现设置合理的固定衰减时间、遮掩时间,并且提供快衰减、慢衰减和混合衰减三种衰减模式,供驱动器根据电机运行速度进行智能选择,有效提高电机运行性能;基于0.35μm BCD工艺参数,运用HSPICE仿真软件进行仿真,结果表明电路稳定有效。     

铸造随流孕育装置用可调下料管总成设计

设计提供的随流孕育装置用可调下料管总成,不仅能够满足其下料管出口指向的空间转角调整,及适度加长下料管长度的需要,而且能够满足多浇口铸型砂箱需适时调整下料管出口指向,及在手工浇注造型线上设置随流孕育装置时,要求下料管总成能够一起随行的配备要求,并且结构简单、实施方便.本总成已于2008年获国家实用新型专利授权.     

Design of Experiment Based Analysis for Sheet Metal Blanking Processes Optimisation

The blanking of metal parts for electronic components is subjected to a variety of process parameters. In this paper, an experimental investigation into the blanking process was carried out using tools with four different wear states and four different clearances. The aim was to study the effects of the interaction between the clearance, the wear state of the tool and the sheet metal thickness on the evolution of the blanking force and the geometry of the sheared profile. Designed experiments are an efficient and cost-effective way to model and analyse the relationships that describe process variations. The results of the proposed experimental investigation show the strong dependence between the geometrical quality of the blanked part and the magnitude of the force applied on the tool as well as the variations in the process factors .     

四柱液压机冲裁缓冲系统研究

简要叙述了液压机冲裁缓冲系统工作原理，并研究分析了影响缓冲效果的因素及解决办法。     

Optimum selection of variable punch-die clearance to improve tool life in blanking non-symmetric shapes

Punch-die clearance is a well-known parameter affecting both tool life and edge quality of parts in blanking and piercing. Selecting the optimum or best punch-die clearance can give a significantly longer tool life by minimizing tool wear. Previous studies have shown the effect of punch-die clearance on various sheet materials and thicknesses during blanking of round parts while non-round geometries are more commonly found in industrial applications. Therefore, in this study, the effect of part geometry is considered to select the ‘best’ punch-die clearance to minimize tool wear. In blanking non-round geometries, the punch and die undergo non-uniform wear, with higher wear observed in areas with sharp radii and abrupt changes in geometry. In the present study, the effect of punch-die clearance on punch stress for blanking various shapes is investigated using Finite Element (FE) analysis. The punch-die clearance that gives the lowest value of the punch stress for the different part geometries is identified. A method is developed to select a geometry dependent variable punch-die clearance to obtain more uniform wear on the punch, thereby increasing the punch and die life.     

基于Windows的冲裁模数据库系统———WBDDB

系统地介绍一个基于Ｗｉｎｄｏｗｓ的冲裁数据库系统－ＷＢＤＤＢ的系统结构，并详细地讨论了ＷＢＤＤＢ中的一些重要模块的实现方法。