共查询到19条相似文献,搜索用时 203 毫秒
1.
热冲压成形模具冷却系统临界水流速度研究 总被引:6,自引:0,他引:6
为保证热冲压过程中模具具有良好散热效果,优化超高强度钢板热冲压成形模具冷却系统设计,提出热成形模具冷却系统中的临界水流速度.采用解析法建立热冲压模具冷却系统中模具与支撑柱及水流传热模型,获得临界水速的解析公式;通过计算机数值模拟的方法,分析了冷却水流速度对模具向支撑柱和向水流传热的热流密度的影响,验证了临界水速的存在性,继而探索了临界水速下支撑柱半径对模具散热量的影响.结果表明,热冲压模具冷却系统中,水流速度达到临界水速时,模具冷却系统中支撑柱尺寸及有无支撑柱均不影响模具总散热量,即冷却系统中水流速度为临界水速时,模具设计可不考虑支撑柱尺寸的影响,从而给优化热冲压模具冷却系统设计提供了理论支持. 相似文献
2.
利用板料成形CAE软件DynaForm对高强板汽车覆盖件地板中通道进行回弹仿真分析,结合模具几何补偿,通过对成形工艺参数的正交优化,找到了最优参数组合及各因素对回弹的影响程度,有效地控制了零件在多工序冲压成形过程中产生的回弹. 相似文献
3.
汽车覆盖件冲压回弹仿真的研究 总被引:1,自引:0,他引:1
为了解决汽车覆盖件冲压成形过程中的回弹问题,以板料冲压成形有限元理论和仿真方法为基础,对某汽车U形梁采用板料成形仿真软件Dynaform,在计算机上模拟冲压成形及回弹的过程,预测出实际的模具制造过程中可能出现的回弹量,通过将仿真结果与实验对比,说明了仿真设计方法的实用性,从而总结出控制回弹的措施. 相似文献
4.
5.
为避免汽车覆盖件冲压时出现起皱、开裂等成形缺陷,提出基于带精英策略的非排序遗传算法(NSGA-Ⅱ)对冲压成形工艺参数进行优化,实现对冲压成形质量的控制与预测。以某型汽车后背门内板作为研究对象,以压边力、摩擦系数、冲压速度和模具间隙作为试验因素,拉延变形时的最大增厚率和最大减薄率作为质量控制目标。应用拉丁超立方抽样方法并结合CAE分析技术建立试验样本,构建冲压工艺参数同成形质量控制目标之间的响应面模型,基于NSGA-Ⅱ算法在构建的响应面模型内计算获得了满足成形质量的一组最优工艺参数组合,同时给出了成形质量的预测值。实际冲压试模结果证明了文章所提方法的有效性,为汽车覆盖件的冲压成形质量控制与预测提供了一套可借鉴的方法。 相似文献
6.
汽车覆盖件冲压成形仿真研究进展 总被引:2,自引:0,他引:2
汽车覆盖件冲压成形仿真技术的发展,突破了原有汽车冲压件模具及工艺设计的设计方法,对保证工件质量、减少材料消耗、缩短产品开发周期、降低制造成本具有重要意义.概述了目前汽车覆盖件冲压成形仿真所涉及到的热点领域,如摩擦与接触、回弹分析、模具系统和工艺参数、材料屈服模型和板料形状设计,讨论了这些领域的研究进展和进一步研究的发展方向. 相似文献
7.
8.
9.
正铝板比钢板密度小,重量轻,铝板零件通常用于汽车的发动机盖和行李箱盖等零件,利于吸能,提高碰撞安全性,并且具有一定的防腐蚀性能。但是铝板成形性差、回弹量难以控制,相似零件的回弹量是钢板的3倍,冲压易产生碎屑,模具结构比钢板模具复杂。目前铝板覆盖件冲压模具研发技术主要掌握在欧美和日本等发达国家,国内尚不具备完善的铝板模具技术的开发能力。在铝板模具结构设计方面,相关资料少,缺乏标准规范。本文通过某项目铝板发动机盖外板模具的研发实验,对铝板模具做了总结归纳。 相似文献
10.
以22MnB5热成形钢为材料,基于类B柱零件U形件,研究热冲压模具冷却系统设计制造、工艺试验以及性能验证。基于传统经验公式,计算得到冷却水道尺寸以及相对位置等重要设计参数,并制造出热冲压模具;建立共轭传热仿真模型,实现U形件在设计模具内保压淬火过程的数值模拟,保压10 s后模具表面和成形件表面最高温度出现在侧壁,最高温度为388 K。利用开发的热冲压模具,开展U形件冷冲压后保压淬火试验,用热电偶记录的模具表面3个测量点温度分布情况与模拟结果吻合良好,用红外测温仪记录的不同保压时间下成形件表面温度变化情况与模拟结果吻合良好,验证了仿真模型的准确性。通过在成形件上截取拉伸试样进行力学性能测试验证冷却系统工作性能,基于传统经验设计方案的试样的抗拉强度达到1 504 MPa;微观分析结果显示在模具内保压淬火后成形件的金相组织为大量马氏体和极少量贝氏体的混合组织,说明冷却系统性能良好。 相似文献
11.
板料冲压成形过程出现的起皱、破裂等缺陷影响产品品质。利用有限元软件对城市轨道车辆上弯梁零件的成形进行了模拟分析,研究了摩擦系数、冲压速度对成形极限和壁厚变化的影响,为预测和控制该类零件的冲压成形品质提供指导。 相似文献
12.
F. Lambiase A. Di Ilio A. Paoletti 《The International Journal of Advanced Manufacturing Technology》2013,64(5-8):829-840
The effect of passive water cooling in laser forming of thin sheets made of AISI 304 stainless steel is experimentally investigated. Indeed, since each laser scan can produce only small bending angles, multiple laser scans are required to produce a given deformation with a significant increase of production time due to cooling between consecutive scans. Therefore, passive water cooling is tested to verify its influence on minimum time between consecutive scans (cooling time), bending angle, and surface quality. A parametric approach is involved in the investigation and main process parameters are changed among the experiments by varying laser scanning speed, laser beam power, sheet thickness, and cooling media among several levels. It was discovered that the employment of passive water cooling in laser forming of thin sheets would be beneficial since the capability to dramatically reduce the cooling time and oxidation of both irradiated and cooled surfaces. In addition, the bending angle is only marginally affected by employment of water cooling. The effect of water cooling on stress and deformations are discussed by developing a numerical model based on finite element model. 相似文献
13.
以铝制错列锯齿翅片为研究对象,利用ANSYS/LS-DYNA非线性动力有限元求解功能,模拟了翅片成形过程与卸载后回弹变形的全过程,得到了成形过程中任意时刻各处的应力、应变和卸载后板料的回弹结果。研究翅片成形过程中压边力、板料厚度、冲压速度、刀具齿形组合、刀具圆角半径等对回弹的影响。利用回弹规律进行模具补偿设计,以此优化专用翅片成形机及模具的结构参数和工艺参数,从根本上提高铝制错列锯齿翅片的制造精度,为翅片的结构优化设计提供了可靠的依据。 相似文献
14.
工程机械车辆常出现散热系统过热问题,针对某型号装载机散热器组的散热性能,在自行开发的整车散热系统测试平台上进行实验研究.利用测试数据对车辆散热器组的散热进行分析,获取车辆散热系统散热器组的散热特性,在此基础上提出了改进方案,在新型车辆上尝试采用新方案并得到了满意的实验结果. 相似文献
15.
《机械工程学报(英文版)》2019,32(3)
In order to control the ferrite and austenite percentage in duplex stainless steel welding, many researchers try to change the laser welding parameters and cooling medium, but ignore to study the influence of heat sink e ect on weld strength. In this work, the e ect of aluminium heat sink and varying cooling medium on the laser welding of duplex stainless steel(DSS) 2205 is studied. The 2 mm thick DSS sheets welded with pulsed Nd: YAG laser welding machine by varying the cooling medium(air and oil) and an aluminium plate used as a heat sink. The welded specimens tested for tensile strength, micro-hardness, distortion, microstructure and radiography analysis. The faster cooling rate in the oil quenching process enhances the ferrite percentage compared with air-cooled samples. But the faster cooling rate in oil quenching leads to more distortion and using aluminium as a heat sink influenced positively the distortion to a small extent. The lower cooling rate in air quenching leads to a higher tensile strength of the welded specimen. The objective of this work is to analyse experimentally the e ect of cooling medium and heat sink in the mechanical and metallurgical properties of laser welded duplex stainless steel. 相似文献
16.
Hongsheng Liu Chengxi Lei Zhongwen Xing 《The International Journal of Advanced Manufacturing Technology》2013,69(1-4):211-223
The innovative hot stamping press of quenchable steel mainly includes two stages: hot forming of blank at elevated temperature and quenching of hot stamped part in closed water-cooled tools. Crucial stage in hot stamping process is quenching of hot formed part in water-cooled tool to achieve final high ultimate tensile strength. In quenching stage, cooling rate of hot stamped part has a significant effect on final mechanical properties of hot stamped part. Hence, in this paper, a new method is proposed to optimize cooling system to improve effectiveness of quenching and thus final mechanical properties of hot stamped part. In this method, cooling channel is introduced in tools, and hot stamping experiments are combined with corresponding finite element numerical simulations to optimize cooling system. According to cooling system optimization, two different sets of tools used to manufacture square-box-shaped part and B pillar of automobile are manufactured using drilling method and pre-embedding method, respectively. Hot stamping experiments and corresponding simulations are performed to verify the effectiveness of optimized cooling system. 相似文献
17.
18.
伺服冲压运动设计是伺服压力机实施伺服冲压作业的核心技术之一。提出NURBS运动曲线混合阶次插值方法,能任意给定冲压运动关键点上位置、速度或加速度中的一个或多个约束,以同时满足伺服冲压运动精确性和灵活性要求;提出快速生成给定时间的保压段冲压运动曲线算法;给出构造插值方程过程中合理设置切矢模长的取值方法,以避免运动曲线畸变;提出适当改变速度或加速度约束调节运动曲线性能的方法;在此基础上引入板料成形和伺服电动机驱动能力等约束,提出伺服冲压运动设计的一般流程,开发出交互式伺服冲压运动设计软件;以某型汽车翼子板拉深冲压运动设计为例进行了验证。 相似文献