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提出了转向节预成形优化设计新工艺.针对某转向节半封闭式锻造成形过程,利用有限元法进行了数值模拟分析,研究了坯料四个关键部位尺寸对成形质量的影响;通过模拟转向节成形过程,预测成形缺陷,确定了预成形优化工艺参数.结果表明,通过预成形优化设计,成功解决了成形过程中的缺陷,有效地降低了最大成形载荷,提高了模具寿命,在很大程度上减少了试模时间和生产成本,提高了生产效率. 相似文献
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热水器水桶固定支架成形分析与成形模具设计 总被引:2,自引:2,他引:0
形状复杂板金冲压件一直是冲压成形的难题.以热水器水桶固定架为案例,对形状复杂板金冲压件成形进行了分析,对生产中使用的模具结构进行研究,找出了影响工件成形原因;根据热水器水桶固定架工件结构特点,优化设计了成形模.通过生产证明,此模具结构提高了工件质量. 相似文献
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In metal-forming industries, die is an important tool for fabrication of metal-formed products. Die service life, which is defined as the maximum product number produced by die before it fails, and die performance directly determine the quality of metal-formed product and production cost. In cold forming process, die service life basically refers to the die fatigue life. The die fatigue life is determined by the design of metal-formed product and die, forming process configuration, die stress and the entire metal-forming system. In this paper, a methodology for optimization of die fatigue life is developed via the rational design of metal-forming system in such a way that the die stress is optimal and further the die design in terms of its service life is the best. To realize this thought, the S–N approach is employed for evaluation of die fatigue life. The die stress is first identified via the integrated simulation of billet plastic flow and the die deformation during the forming process. The die stress is then optimized via the rational design of the combination of metal-formed product, die and process configuration. The optimal die life is thus determined. Furthermore, a framework for implementation of this methodology is developed and case studies are used for verification and validation of the developed methodology. 相似文献
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Understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography 总被引:1,自引:0,他引:1
The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic part just after mold opening as well as after part ejection. The wall thickness and dimensions of the bottles of the finished parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final part characteristics. 相似文献
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以实际生产中某MPV车型出现的顶盖尾部造型两位置的起皱案例为基础,通过对模具结构以及原有生产工艺进行分析,结合现场生产情况的跟踪调查,采用CAE软件对冲压件生产过程进行模拟,找出起皱产生的主要原因,并分别针对两位置的起皱原因制定顶盖尾部起皱优化工艺。在前工序加工过程中,会因工艺型面R角产生加工硬化;而在后工序整形中,该硬化部分形状不能恢复平整,导致出现型面起皱缺陷。通过消除加工硬化,提高零件装车匹配性及车身精度,避免顶盖在冲压成形过程中因起皱、叠料导致的凸、凹模型面磨损快,提高模具使用寿命。 相似文献
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在现代工业生产中,冲压模具的使用非常普遍.冲压模具寿命的高低是影响冲压产品成本的重要因素.提高模具寿命、降低产品成本是模具生产、制造和使用企业不断追求的目标.影响冲压模具寿命的因素很多,本文从模具设计、选材、制造加工工艺以及模具零件的表面处理等方面,对提高冲压模具使用寿命的方法进行探讨,供同行参考. 相似文献
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Design of forging process variables under uncertainties 总被引:4,自引:0,他引:4
Jalaja Repalle Ramana V. Grandhi 《Journal of Materials Engineering and Performance》2005,14(1):123-131
Forging is a complex nonlinear process that is vulnerable to various manufacturing anomalies, such as variations in billet
geometry, billet/die temperatures, material properties, and workpiece and forging equipment positional errors. A combination
of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion,
and reduced productivity. Identifying, quantifying, and controlling the uncertainties will reduce variability risk in a manufacturing
environment, which will minimize the overall production cost. In this article, various uncertainties that affect the forging
process are identified, and their cumulative effect on the forging tool life is evaluated. Because the forging process simulation
is time-consuming, a response surface model is used to reduce computation time by establishing a relationship between the
process performance and the critical process variables. A robust design methodology is developed by incorporating reliability-based
optimization techniques to obtain sound forging components. A case study of an automotive-component forging-process design
is presented to demonstrate the applicability of the method. 相似文献
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中、小型企业由于设备条件受限(吨位小、数量少),对于批量生产、尺寸较大、工艺流程较长的机架零件,其产量和质量都难以保证,为此,我们研究了工序合并及降低冲裁力的方法,介绍了合并后的工艺方案及模具。通过工艺合并及模具结构改进,实现了工艺与企业硬件系统的最佳匹配,使加工工效提高30%以上,模具寿命达到50万次以上,企业经济效益显著。 相似文献
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为了提高车辆A柱加强板的热冲压质量,提出了响应面法与NSGA-Ⅱ算法相结合的工艺多目标优化方法。以最小化冲压件的最大减薄率和最大增厚率为优化目标,选择板料初始温度、摩擦系数、上下模压料力等作为优化参数,使用Box-Behnken方法设计了4因素3水平实验,依据Autoform有限元软件得到了实验仿真结果。基于二阶响应面法,拟合质量参数-工艺参数之间的非线性关系,经决定系数法检验,响应面法的拟合精度较高。通过基因编码将优化问题转化为寻优问题,使用NSGA-Ⅱ算法搜索到多目标优化的Pareto前沿解。选择Pareto解集中的一个优化方案:初始温度为947.25℃、摩擦系数为0.429、上模压料力为3.06 MPa、下模压料力为1.05 MPa。经仿真和实验验证,优化后冲压件的最大减薄率均值减小了6.79%,最大增厚率均值减小了8.47%,说明优化后冲压件质量明显提高。另外,优化后冲压件的标准差略有下降,说明优化后冲压件质量的一致性略有提高。 相似文献
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拉伸成形工艺是飞机蒙皮零件的基本成形方法。针对某大厚度双曲度铝合金飞机蒙皮进行了拉伸成形工艺研究和优化。为了保证数值模拟的准确性和可靠性,进行了材料性能测试试验,获取了该蒙皮多道次加工时每一道次、不同热处理状态下的材料性能。通过数值模拟,研究了拉伸成形工艺参数包括各道次拉伸量、上模压力、合模间距对贴模和回弹的影响规律。结果表明:合模间距为7 mm时,成形后零件的厚度在大部分区域基本均匀;上模压力在200~1000 kN之间时,增加压力能有效地改善贴模度。据此,提出了优化拉伸成形工艺。针对该蒙皮零件厚度大而导致的回弹大、仅靠工艺优化不能完全满足贴模度要求的问题,进行了模具型面补偿研究。结果表明,该工艺可用于生产满足质量要求的蒙皮零件,并能减少成形道次、降低加工成本、提高生产效率。 相似文献