多列排样多工位连续模（下）

3.多列排样冲压工艺与模具结构特点 节材、高效是多列排样冲压的优势,但必须以先进的冲压工艺及完善的制模技术为基础。因为多列排样冲压的冲模结构复杂,尤以一模成形的多工位连续模最为典型。小型复杂冲压成形件一模成形若     

弹簧夹六工位连续式复合模结构设计

需要多种冲压工艺作业进行组合冲压的多弯角复杂形状弯曲件,当采用条料或带料用多工位连续模连续冲压一模成形时,其连续冲压工艺及其排样图是这类多工位连续模结构设计的主要依据。而弯曲件展开平毛坯的成形冲压、工位间的送进与传递、各个分离与成形工位的合理排布及每个工步的冲压方法等,则构成多工位连续模结构设计的关键。这里介绍的弹簧夹弯曲件的连续冲压工艺及其六工位连续式复合模的结构设计,具有较广的代表性和推广应用的价值。     

级进模CAD冲压特征工序设计自动化的研究

介绍了级进模CAD系统中，冲压工艺特征工序设计自动化方法。建立了冲压工艺特征的计算机模型和冲压工艺特征库，提出了设计零件上的冲压工艺特征和冲压工艺库的特征进行匹配的技术和算法，给出了特征参数的计算方法。探讨了这种技术在级进模CAD系统中的实现。     

级进模冲压加工过程的计算机仿真

论述了计算机仿真技术在冲压工艺及级进模结构设计中的应用。针对某一典型级进模冲压工艺过程进行了计算机仿真,并建立了主动性对象系统的Ｐｅｔｒｉ网仿真模型。     

冲压设备快速换模技术研究

针对冲压设备换模工艺时间长的问题,建立了换模时间与冲压工序在制品数量的关系模型,并在该模型的基础上,提出了一种综合应用流程图、排列图和鱼骨图寻找和优化影响换模时间因素的快速换模改进方法,减少了冲压设备的换模时间和冲压工序的在制品数量,并用实例验证了模型和方法的可行性。     

基于CAE技术的汽车座椅配件冲压分析与设计优化

根据某型号轿车座椅配件的成形精度和生产批量等要求,分析冲压件的结构特点和冲压工艺,提出采用多工位级进模的冲压方案。然后应用冲压分析软件FormingSuite对钣金件进行自动展开计算,最后基于冲压CAE技术得出最危险的区域并根据分析结果对冲压工艺过程进行调整和优化。根据CAE结果优化后制造的级进模一次试模完成。实践证明,CAE技术可以避免模具设计的缺陷和减少修模的次数。     

弹性阀座加工方法的改进

对弹性阀座的机械加工工艺和冲压加工工艺进行了对比,并分析了冲压加工所产生的误差,介绍了冲压加工的特点及级进模的结构。     

汽车消声器隔板一模三件成型级进模设计及应用

通过对比分析汽车消声器隔板冲压件单冲模和级进模的冲压工艺,阐述级进模冲压工艺所具有的效率及成本优势,并着重介绍消声器隔板一模三件成型级进模排样工艺及模具结构设计,以及介绍相关设备选择方法,对同类型级进模技术的开发具有一定的参考价值。     

弯曲件的连续冲压成形（上）

现代冲压技术可利用多工位连续冲压工艺一模成形冲制出各种复杂形状的板料弯曲件。即可以直接从条、带、卷料冲制出任意形状的弯曲件,便于机械化与自动化冲压,既可优质高产,又可确保操作安全,是冲压生产技术的发展方向。 一、一模成形的连续冲弯工艺 用多工位连续模冲制板料弯曲件的工艺过程,根据弯曲件的形状及复杂程度、料厚、排样方式,归纳起来有如下几种: (1) 展开平毛坯采用无搭边排样的板料弯曲     

门部件左右限位块冲裁模的设计

分析了门部件左、右限位块零件的工艺设计和冲孔、落料级进模、切断弯曲复合模的主要工作原理．论述了工艺分析在模具设计中的主导地位,并介绍了模具结构、工作原理及模具的使用情况,指出冲压工艺方案的合理性,是设计好模具的首要条件。     

Microstructure and mechanical properties of AM50 alloy according to thickness and forming condition of the products by a high pressure die-casting process

In recent years, Magnesium (Mg) and its alloys have become a center of special interest in the automotive industry. Due to their high specific mechanical properties, they offer a significant weight saving potential in modern vehicle constructions. Most Mg alloys show very good machinability and processability, and even the most complicated die casting parts can be easily produced. The die casting process is a fast production method capable of a high degree of automation for which certain Mg alloys are ideally suited. Although Mg alloys are fulfilling the demands for low specific weight materials with excellent machining and casting abilities, they are still not used in die casting process to the same extent as the competing material aluminum. One of the reasons is that effects of various forming variables for die casting process is not closely examined from the viewpoint of die design. In this study, step die and flowability tests for AM50 were performed by die casting process according to various combination of casting pressure and plunger velocity. Microstructure, Vickers hardness and tensile tests were examined and performed for each specimen to verify effects of forming conditions.     

Development of a die design system for die casting

This paper presents a research work of a computer-aided die design system for die casting. The proposed system consists of seven distinct modules. Through these modules, the die designers are able to create a die casting die from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design.The practical goal of this research is twofold: (1) to develop a system that integrates the different stages of die design process and (2) that at the same time facilitates the editing of die casting design during or after the course of the design process. The approach undertaken in this research includes (1) feature-based and constraint-based modelling, (2) parametric design and (3) a geometric and topological information extraction technique from a B-rep model. A prototype system has been developed using this approach and the system is able to aid the automation of the die casting die design process, thus improving the efficiency and quality of, and reducing the cost of die design for die casting.     

薄壁深抛物线形零件固体颗粒介质成形工艺

薄壁抛物线形壳体成形过程为拉深和胀形两种变形模式的复合,极易发生起皱和破裂。固体颗粒介质成形是采用固体颗粒代替刚性凸模或凹模(或弹性体、液体)对板料进行成形的工艺。板材在颗粒介质内压的作用下成形,可以有效防止抛物线形件拉深成形过程中侧壁的起皱;由于颗粒内压是非均匀分布的,故可以有效控制抛物线形件成形过程中的破裂,提高板材的成形极限。根据固体颗粒介质成形工艺的特点,提出了两次成形薄壁深壳体零件的工艺,建立了数值分析模型,通过数值模拟和试验对该成形过程和工艺参数进行了分析。结果表明,采用固体颗粒介质成形工艺过程简单、成形工件壁厚分布均匀、表面质量好、回弹小。     

Design and manufacturing of a straight bevel gear in hot precision forging process using finite volume method and CAD/CAE technology

Forging simulation offers significant cost and time advantages by providing detailed insight into the forging process before tool selection and process decisions are made on the shop floor. Process data such as material flow, stresses, strains and temperature are readily accessible to a user at any point throughout the simulation process, as well as at any location within the forged part. Potential defects such as laps and under-fill of die cavities can be easily identified and corrected before part production begins. In addition, the influence of the process conditions such as lubrication and pre-form can be easily quantified and assessed. In the present work, hot precision forging process of the straight bevel gear is simulated numerically using finite volume method and computer-aided design/computer-aided engineering technology. The required force for the forging process, as well as the final shape of the bevel gear, is determined through numerical estimation. The simulation results are confirmed through the comparison with the experimental data available in DIN standards. Finally, the pre-form dies, the final die, and the bevel gear are manufactured. It is concluded that this method can be effectively used to optimize the forging process to maximize the mechanical strength, minimize material scrap, and hence reduce the overall cost of manufacture.     

覆盖件冲压仿真参数化建模方法

针对在覆盖件冲压成形领域对快速、自动化的有限元网格建模方法的迫切需求,提出一种快速的汽车覆盖件冲压仿真建模的思路与方法.将覆盖件冲压工艺设计与冲压成形仿真前处理集成,使用散乱三角面片模型,在自主开发的CAE前处理软件中,进行参数化的工艺补充面和压料面设计.模型的网格剖分与冲压工艺设计同时进行,自动生成整套模具的网格模型供冲压仿真计算.为了真实地模拟板料网格的流动,提出了参数化的真实拉深筋的模型建模方法和板料网格的预细分方法.完成了相关软件的开发.多个汽车覆盖件冲压工艺设计和冲压仿真计算实例说明了该方法的有效性.     

防护罩冲压工艺及模具设计

分析了防护罩的结构和冲压工艺性,确定了冲压成形工艺方案,设计了1套落料拉深冲孔复合模,并对冲压成形的结构特点、工作原理和设计要点进行了介绍.实际生产表明,该模具结构合理,工作稳定,安装、调试、维修方便,生产效率高,产品精度高.     

2A70铝合金转子等温闭塞式锻造工艺研究

2A70铝合金转子是导弹发动机上重要的受力构件,对组织性能的要求很高。采用等温闭塞式锻造的方法生产转子锻件。为了使成形后的锻件顺利出模,采用了组合式凹模的结构。等温成形时,进行了大量的试验研究加热温度对成形过程的影响,最终确定模具和坯料的加热温度均为435 ℃。经检测,采用所设计的工艺方案生产的转子锻件的尺寸精度及组织性能均符合设计要求,成功地解决了切削加工的转子力学性能差、不能满足使用要求的问题。     

Development of an unconventional electro-hydraulic proportional valve with fuzzy-logic controller for hydraulic presses

A micro slit die easily manufactured using a micro electrical discharge machining (MEDM) is proposed for micro heat sink fabrication. In the investigations described in this paper, processed concave and rectangular shaped copper foils were combined piece by piece to form an assembled electrode. This electrode was used to fabricate a micro slit die. This die included 15 micro fins in a small tungsten carbide plate. The micro heat sink was made by applying a pressing or scraping method when the micro slit die was used. The experiments showed that debris, produced by the MEDM, might cause a discharge concentration effect because of the narrow gaps between the workpiece and electrode. Parts of the micro fin were seriously melted during this process. Flushing dielectric could effectively remove the debris from the narrow gap, generating an appropriate discharge dispersing effect. However, the discharge effect was unstable when large flushing pressure was applied, thus reducing the machining precision. The micro fins were formed into a rectangular shape using kerosene as the MEDM dielectric. Using distilled water as the MEDM dielectric produced a higher material removal rate and serious assembled electrode wear. Therefore, the micro fins formed as triangle profiles. The micro heat sink was higher even when the pressing method was used. The heat sink deviated and was full of burrs on the fin edge when the scraping method was used.     

通用可微调快换冲模设计

设计了一种可应用于组合冲模及柔性冲压系统的快换冲模机构。通过斜楔机构的设计，模具间隙可做微量调节，工作安全可靠。模具更换快捷、方便并带自锁功能。适合中小型冲压制品的多品种、中小批量生产及系列产品的开发。     

U型支架成型、翻边复合模设计应用

通过对某车型U型支架的工艺分析,介绍一种成型、翻边复合模具,并且详细介绍了此模具在设计过程中的要点、工作原理及制造工艺.实践证明了该模具方便、适用、可靠、操作简便、非常有效地保证了产品质量、完好性,提高了生产效率,具有一定的参考价值.