覆盖层密集精密小孔冲压工艺及模具设计

阐述柔性印刷线路板 (FPCB)覆盖层四排密集精密小孔的冲压工艺 ,分析冲压产生孔边毛边、凹模强度低、凸模易断等问题 ,并设计合理的冲压工艺和模具结构     

普通冲孔与无飞边精密冲孔的瞬时间隙及对冲孔质量的影响

提出了瞬时间隙的概念 ,研究了瞬时间隙对冲孔剪口质量的影响 ,对普通冲孔工艺与精密无飞边冲孔工艺凸、凹模间的瞬时间隙进行了对比分析 ,认为普通冲孔时瞬时间隙不定常是造成剪口质量差的根本原因 ,而无飞边精密冲孔时凸、凹模间为负间隙 ,其瞬时间隙保持定常 ,因此可使剪口光洁剪切带长度提高 1.5倍 ,且冲制的孔无纵向飞边     

热冲压模具冷却管道设计计算

以典型热冲压件—汽车B柱为例,在对实际生产工况分析的基础上,基于传热学基本原理计算并确定热冲压模具冷却管道的工艺参数。在尽量保证冷却管道与模具型面距离一致以及各截面上冷却管道均布的前提下,采用多镶块拼接的方式分别设计出凸模、凹模的冷却管道。     

某汽车保险杠横梁前板成形质量控制研究

针对汽车冲压件的成形质量问题,以某汽车保险杠横梁前板为例,采用正交试验进行工艺参数方案设计,并借助Dynaform软件进行工艺参数分析,以开裂和回弹量为优化目标,完成了压边力、模具间隙、摩擦系数和冲压速度4个工艺参数的优化,利用模面回弹补偿方法对拉延模进行回弹补偿,经3次回弹补偿迭代后,冲压件回弹量符合要求。将补偿后的模面加工,并完成试模。实验表明经工艺参数优化和拉延工序模面补偿后,某汽车保险杠横梁前板成形质量得到有效控制。     

基于Taguchi方法的镍涂层薄板冲压工艺参数研究

从厚度减薄和厚度分布角度出发,结合Taguchi实验设计方法,建立了镍涂层薄板的数值仿真模型,分析研究了凹模圆角半径、压边力、摩擦系数等工艺参数对镍涂层薄板冲压成形性能的影响,最终确定了各个工艺参数对成形质量(厚度变化)的影响及其相对影响程度。同时,通过对比仿真数据与实验结果,验证了该仿真模型的有效性。     

音响盖板精密级进模具设计与制造

通过对音响盖板冲压件的冲压工艺性进行分析,确定了音响盖板冲压件的工艺方案和排样设计方案,详细介绍了精密级进模具的结构形式及模具关键零件的设计、制造方法要点、模具试验装配过程。通过实验试模,实现了多工位精密级进模的设计开发和自动化生产。实践表明,与原来采用的单工序冲压相比,不仅保证了产品质量,减小了劳动强度,生产效率也显著提高,并由冲压设备、机械手、精密级进模具、成型模具、自动攻丝机和零件自动清洗防锈处理流水线共同组成了汽车冲压件自动化生产线,实现了音响盖板自动化生产。     

基于正交实验的铝瓶盖冲压成型参数优化

以某型号药用铝3003瓶盖为研究对象,针对瓶盖顶部凸环内壁处拉深变薄率较高,生产中拉裂安全裕度不够的问题,通过将正交试验设计与冲压数值模拟相结合应用的方法,以ABAQUS有限元软件为仿真优化平台,综合评估了冲压过程中的压边力、坯料直径、凹模圆角和模具间隙等参数对冲压件冲压成形质量的影响;通过对仿真数据的极差分析和工艺分析,确定了优选的工艺参数组合。实验表明,基于正交试验对瓶盖成形工艺参数和结构参数优化的方法可行,所得结论对拉深工艺的设计具有指导意义。     

基于Dynaform的汽车零件冲压成形模拟的研究

在Dynaform软件中,对汽车某冲压件进行冲压模拟分析,提出了具有圆滑特点的工艺补充面的设计思想,有效改善板料在凹模内流动情况,避免拉裂等缺陷产生。通过反复的工艺修改、比较及重分析,确定了合理的工艺补充面及拉延筋的布置形式,仿真计算结果满意。为实际生产提供参考,证明了仿真设计方法的实用性。     

基于逆向工程技术的反求因子回弹补偿法

为减少冲压回弹导致的模具型面补偿的次数,在一步法模面几何修正的基础上,提出了反求因子补偿法:通过逆向工程技术获得试模冲压件的数字模型,将该模型当作假想的理论模型进行成形、回弹模拟,计算出仿真回弹量;由试模模面和试模件取差值获得真实补偿量,进而计算出补偿因子。假定在冲压件小变形、仿真参数、冲压工艺不变的情况下补偿因子基本保持不变,对实际设计零件做回弹仿真,再引入该补偿因子,计算出模具补偿型面。实验结果表明,该方法通过一次模面补偿,可有效控制回弹,提高补偿效率。     

KMAS冲压仿真在压力锅盖工艺优化中的应用

在优化冲压成形工艺过程中,为了防止仅仅依靠经验而造成设计周期长、成本高,甚至难以控制冲压件成形质量的问题,需要先在计算机上进行试模.介绍使用KMAS软件进行冲压成形仿真的流程和关键步骤,并模拟了铝合金压力锅盖拉深件的一次拉延成形工艺.研究了工艺参数对冲压件成形质量的影响,经过不断改变冲压速度、压边力、摩擦系数等工艺参数,最终得到较好的模拟结果,提出了合理的工艺参数设置,为后续工件的一次拉延工艺优化设计提供参考.     

An Analysis of Draw-Wall Wrinkling in a Stamping Die Design

Wrinkling that occurs in the stamping of tapered square cups and stepped rectangular cups is investigated. A common characteristic of these two types of wrinkling is that the wrinkles are found at the draw wall that is relatively unsup-ported. In the stamping of a tapered square cup, the effect of process parameters, such as the die gap and blank-holder force, on the occurrence of wrinkling is examined using finite-element simulations. The simulation results show that the larger the die gap, the more severe is the wrinkling, and such wrinkling cannot be suppressed by increasing the blank-holder force. In the analysis of wrinkling that occurred in the stamping of a stepped rectangular cup, an actual production part that has a similar type of geometry was examined. The wrinkles found at the draw wall are attributed to the unbalanced stretching of the sheet metal between the punch head and the step edge. An optimum die design for the purpose of eliminating the wrinkles is determined using finite-element analysis. The good agreement between the simulation results and those observed in the wrinkle-free production part validates the accuracy of the finite-element analysis, and demonstrates the advantage of using finite-element analysis for stamping die design.     

射灯罩复杂件成形工艺及模具

常用的广告牌射灯灯罩是一种复杂成形件,由于灯光反射度的要求,表面要求比较高,所以成形难度较大,通过对其结构和冲压工艺分析和计算,制定了一套可行的成形工艺,设计了一种复合模具,拉深成形和凸缘切边一次完成,再通过一副横向和纵向冲孔模完成冲孔,全套生产工艺仅需两副模具。介绍了该成形复合模具的结构、灯罩的冲压过程和模具的设计要点。     

面向设计的板料成形快速仿真系统FASTAMP

FASTAMP是基于改进的有限元逆算法和动力显式算法的板料成形快速仿真软件。改进的逆算法求解器采用了考虑弯曲效应的DKQ四边形单元及方程组快速求解算法,真实考虑了摩擦、压边力、背压力和曲压料面等实际工艺条件,在模拟精度和速度上均有较大的提高。系统结合了两种算法的优势,将产品设计、选材和工艺设计三个独立的过程紧密结合起来,可快速分析产品设计中的潜在缺陷,为工艺设计人员提供有效的工艺设计参考和强有力的设计辅助分析工具。     

基于神经网络的板料冲压回弹预测系统的研究

文中以NUMISHEET’93标准考题中U形板料作为研究对象,将正交试验法和数值模拟法结合,产生各工艺参数组合下的冲压回弹量,以这些仿真试验结果作为神经网络的训练样本,在NeuroSolution软件环境下建立输入为工艺参数、输出为冲压回弹量的神经网络模型预测模型,以测试样本验证模型的预测精度作为反馈信息,构成闭环系统。该方法为板料冲压工艺参数的优化提供了有效的工具。     

KBE-based stamping process paths generated for automobile panels

As automobile body panels are one kind of sheet metal part with groups of free form surfaces, the process planning is more complicated than common sheet metal stamping to implode effectively and practically. Based on KBE, new frameworks have been presented as intelligent master model at the system level and as procedure model at the activity level. In accordance with these frameworks, an intelligent CAPP system has been specifically developed. Based on feature technology, features have been extracted and represented by the object-oriented method. Stamping features and their parameters have been defined and extracted based on feature technology and stamping process rules. The whole product knowledge has been represented by frames which directly map to objects (or features) in the object-oriented sense. Relevant appropriate operations features have been assigned to stamping features of a product based on feature-operation criteria, parameters of the stamping feature and their correlativity. This assignment is a decision-making activity using a set of rules with a decision-making tree and model-based reasoning methods. With knowledge between operations, such as operations order constraint (do-after) and operations combination constraint, process paths have been improved based on relevant intelligent reasoning methods. Based on the relationships (preferred-to) between processes and machines/dies, the structure of die and machine for each process can be identified, since the process route has been determined. In this stamping process planning, the procedure and information have been controlled by a process control structure that is associative and integrated.     

基于RP/RT/RE技术的金属板料冲压成形回弹误差补偿系统

针对冲压件回弹误差，建立了基于RP／RT／RE技术的三维复杂形状板料冲压成形回弹误差精度闭环控制系统。以回弹误差为控制目标，以线性控制系统、空间Fourier变换和频域传递函数为理论基础，基于模具实验迭代，建立了模具回弹误差补偿修正算法，并首次将该算法应用于三维复杂形状板料冲压模具制造过程。工程实例表明，该系统对于三雏自由曲面板料冲压模具制造具有良好的工程实用价值，特别能对冲压件回弹误差进行有效补偿。     

基于冲压成形分析的车身覆盖件模具设计

以车身覆盖件为研究对象,根据板料成形特点及回弹规律,在利用Dynaform软件对前围板冲压成形进行了回弹仿真分析、正交试验和基于BP人工神经网络的回弹预测之后,根据前围板的拉深成形特点,在前围板冲压过程工艺分析的基础上,进行了冲压方向选择、工艺补充面、压料面以及拉延筋设计等拉深工艺设计,最后,对前围板拉伸模具进行了设计。     

An experimental study of contact pressure distribution in panel stamping operations

This paper presents an analysis of the dynamic contact pressure distribution at the sheet metal-tooling interface in normal and defective panel stamping operations. Specifically, the stamping of a 1.27?×?20?×?15?cm rectangular aluminum alloy panel has been simulated using finite-element modeling methods. The modeling results are leveraged to determine the forces acting on sensors embedded in the die structure. Based on these results, a customized stamping test bed has been designed, which incorporates an array of force sensors embedded into the stamping die to enable online measurement of the forces in the die. The force measurements are processed by the thin plate spline numeric surface interpolation method to evaluate a continuous contact pressure distribution map of the die cavity. The pressure distribution in the die cavity in normal and defective scenarios has been presented along with a suggested volume thresholding method for automated defect detection. By leveraging the numeric surface generation method to analyze experimental data, the present study establishes the basis for intelligent tooling and in-process monitoring for improved observability in sheet metal stamping.     

冲压模参数化NURBS曲面造型及有限元网格划分

针对冲压模具的特点 ,提出了模具型面参数化NURBS曲面分片 ,局部网格调整的思想 ,较好地解决了板料成形有限元模拟前处理中模具型面造型及网格划分的问题。基于NURBS方法 ,在VC + +平台上开发了一个NURBS曲面造型及网格生成系统 ,对实际的盒形件拉深凹模型面进行了描述 ,获得了满意的曲面形状 ;基于参数空间法对型面进行了四边形网格剖分 ,并自动实现四边形到三角形网格的转换     

Simulation and Experiment on Workability for Cold Pressure Forming of Sheet Metal Part with Step Cross-section

In modem manufacturing, a new type of sheet metal part with step cross-section in both inner hole and outer edge is proposed. The traditional stamping separating processes can only produce sheet metal part with vertical cross-section. According to the latest developing theory and potential of cold pressure forming: combination of pressure and cold forging, a new flow control forming of sheet metal(FCF) is excogitated based on blanking process of general stamping and combined with cold forging processes such as extrusion and coining, etc, which is aiming at the above-mentioned new type of sheet metal part. With utilization of this new process, the new type of sheet metal parts can be manufactured. In order to shorten the testing period, the numerical simulation was carried out by using DEFORM-3D software, and both deformation and mechanics rules were analyzed. Based on the simulation, both punching part and blanked parts of this new type were successfully developed. Then a new conception of optimal distance between the step walls of inner hole and outside edge was proposed and the design principle for its numerical value was inferred. Furthermore, a mold set for combination of stamping & cold forging was designed and manufactured, by which the technologic experiments were taken for validation with Aluminum plate of thickness 2.35 mm for power battery cover board, which verified the principle of the distance between the step walls. The research of cold pressure forming of thin sheet metal with step cross-section is significant, not only to the development of modem mechanical manufacture, but also to metal plastic forming science.