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1.
多腔壁板铝型材挤压过程数值模拟及模具优化   总被引:4,自引:2,他引:2  
挤压模具在铝型材挤压生产中起着至关重要的作用,挤压模具设计的优劣直接影响挤压产品的质量。然而实际生产中,挤压模具的设计更多依赖传统设计经验,需要多次试模和修模,无法满足产品开发需求。以典型的多腔壁板铝型材为例,应用UG建立分流组合模几何模型,采用基于任意拉格朗日—欧拉(Arbitrary Largrang-Euler,ALE)算法的HyperXtrude软件对多腔壁板铝型材的挤压成形过程进行数值模拟,获得挤压过程中速度场、温度场、应力场及金属流动情况。针对初始模具设计的不足,提出多腔壁板铝型材挤压模具优化三步曲(开设引流槽、增设阻流块、优化工作带),有效地解决了初始模具设计中速度分布不均的问题。利用数值模拟方法可以优化模具结构,提出的多腔壁板铝型材挤压模具优化三步曲对同类铝型材挤压模具结构设计具有一定的指导意义。  相似文献
2.
八通缓冲器联接螺栓预紧力控制方法分析   总被引:1,自引:0,他引:1  
分析了八通缓冲器联接螺栓预紧力的控制方法,给出了各种控制方法的工艺参数.通过计算分析得出力矩法是目前最经济有效的控制手段,而液压拉紧器法是最精确而投资最大的一种预紧力控制手段.螺母转角法,力矩/转角法和预紧力指示垫圈法介于上述两者之间.螺栓伸长法由于空间限制无法实施.  相似文献
3.
电动车组电气配线工艺设计系统开发关键技术研究   总被引:1,自引:0,他引:1  
针对公司工艺设计部电气配线组的电动车组电气配线工艺设计系统开发中的若干关键技术进行详细描述,包括用户池与锁池并发处理技术、数据库扩展值对技术、数据库索引优化技术。通过这些关键技术的实施,解决了B/S模式下多用户并发数据操作请求情况下,数据无法保持一致性以及完整性的固有缺陷,大规模数据量情况下多条件数据查询数据库响应速度较慢这一技术难题。  相似文献
4.
The extrusion die plays a crucial role in the quality control of aluminum alloy profile production. But in practice, the design of extrusion die is mainly dependent on the experience and intuition of die designers; thus, many times of modifications and experiments should be undergone until an acceptable product is gained. In this paper, the extrusion process of a large wallboard aluminum alloy profile used for high-speed train was simulated by means of HyperXtrude software, and the flow behavior of material and deformation mechanism in the die cavity were investigated. With the simulation results of the initial die design scheme, a nonuniform velocity distribution in cross-section of the extrudate was observed. For optimizing the die design scheme, two optimal schemes (adoption of double-step welding chamber and introduction of baffle plate) were proposed. Through optimization, the velocity differences in the extrudate for optimal schemes are decreased from 39.9 to 12.2 and 10.8 mm/s, respectively. Thus, the uniformity of velocity distribution was improved in optimal schemes. The extrusion die design methods for large wallboard profiles were summarized and proposed, including the design methods of baffle plate and double-step welding chamber. Through trial production, a sound wallboard aluminum profile with good geometric shape and high dimensional accuracy was gained. Additionally, the mechanical properties of the extrudate were examined by means of experimental method. It is found that the test results stratified the practical engineering requirements.  相似文献
5.
The most important way to improve the quality of aluminum profiles is to assure the material flow through die land exit with the same velocity. In this paper, a numerical model was developed to investigate metal flow behavior during aluminum profile extrusion. Firstly, the numerical model for a complex hollow aluminum profile was built based on the arbitrary Lagrangian–Eulerian program HyperXtrude. Then, with the numerical model, metal flow behavior at each stage during the whole extrusion process was analyzed and dead zones in the die cavity were also investigated by means of the particle tracking method. Finally, the numerical results were validated by comparing with the nose ends of two extrudates in practice, and the comparison showed that the numerical model developed in this work could provide the effective guidance for practical production.  相似文献
6.
Taguchi’s design of experiment and numerical simulation were applied in the optimization of an aluminum profile extrusion process. By means of HyperXtrude, the extrusion process was simulated and the effects of process parameters on the uniformity of metal flow and on the extrusion force were investigated with the signal to noise ratio and the analysis of variance. Through analysis, the optimum combination of process parameters for uniform flow velocity distribution was obtained, with the billet diameter of 170?mm, ram speed of 2.2?mm/s, die temperature of 465°C, billet preheated temperature of 480°C, and container temperature of 425°C. Compared with the initial process parameters, the velocity relative difference in the cross-section of extrudate was decreased from 2.81% to 1.39%. In the same way, the optimum process parameters for minimum required extrusion force were gained, with the billet diameter of 165?mm, ram speed of 0.4?mm/s, die temperature of 475°C, billet preheated temperature of 495°C, and container temperature of 445°C. A 24.7% decrease of required extrusion force with optimum process parameters was realized. Through the optimization analysis in this study, the extrusion performance has been greatly improved. Finally, the numerical results were validated by practical experiments, and the comparison showed that the optimization strategy developed in this work could provide the effective guidance for practical production.  相似文献
7.
针对电动车组系统部件的预防性维修,引入役龄回退因子的概念,建立预防性维修前后故障率的递推关系,对预防性维修后的可靠度进行了预估,为电动车组的修程优化提供了改进方向.  相似文献
8.
对于有超声引入的铝合金大型锭坯半连铸过程,建立了声场、流场和温度场耦合的数学模型,合理地考虑了凝固过程不同状态铝合金的动力粘度和湍动粘度以及边界条件,并利用有限体积软件FLUENT求解得到了三维声场、流场和温度场分布.模拟结果显示,声场对流场和温度场影响很大.若超声振动的工艺参数设置合理,可使流场规模显著增加,有效地促进传热、传质和晶核弥散:可使温度场分布更加均匀,凝固前沿的温度梯度显著减小,对枝状晶向等轴晶转变有极大的促进作用.  相似文献
9.
以沈阳地铁二号线样车的客室侧墙板安装为例,结合侧墙板的工艺流程对侧墙板安装进行工艺分析,并进行探讨。同时,分析了侧墙骨架模块化设计对侧墙板工艺安装的影响。  相似文献
10.
受电弓是关系动车组运行安全的重要设备.文中以CRH380AL型动车组为例,基于动车组四级检修规程并结合现车实际检修经验,对受电弓的四级检修工艺进行了研究.  相似文献
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