共查询到19条相似文献,搜索用时 500 毫秒
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在斜轧方法中,轧辊辊形与轧件的几何关系对于辊形设计及金属塑性流动的研究具有重要的作用。本文建立了斜轧辊形与由辊形所构成的轧制空间的关系的数学模型,利用该数学模型,可进行斜轧穿孔机、延伸机、斜辊式管、棒材矫直机以及行星轧管机的理论辊形曲线的设计和有关金属变形的研究。本文给出了行星轧管辊形设计的具体算例。 相似文献
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本文根据空间解析几何理论,建立了二辊斜轧穿孔时的轧辊辊面方程,继而利用平截面法描绘了轧件与轧辊接触迹线的形状及其随送进角变化的性质。 相似文献
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整体型螺旋高翅片管孔型斜轧运动学分析 总被引:1,自引:1,他引:0
介绍了螺旋翅片管孔型斜轧工艺的主要特点,通过建立运动学分析的几何模型,研究了轧辊与轧件的运动关系,主要包括两者圆周速度的关系以及接触区域的相对滑动情况.研究了变形区轴向和切向速度分布规律.结果表明,沿轧制方向轧件轴向分速度和周向分速度都增大,周向速度增加的趋势远大于轴向速度,从而使轧件在轧制过程中发生扭转和轴向延伸.引入扭转率的概念描述轧制方向上轧件圆周速度的变化程度,给出了表达式,通过公式简单分析了主要参数如轧辊转速、相对压下量、轧辊轧件中心距以及轧片半径等对扭转率的影响. 相似文献
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三辊行星轧机辊型设计方法 总被引:1,自引:1,他引:0
本文给出一种根据预定轧件变形区形状及均整区长度来确定三辊行星轧辊辊型曲线的方法。为了改善轧制质量、消除轧件螺旋纹缺陷,减小轧件出口处的变形阻力以利轧制顺利进行,本文推荐轧件变形区采用幂函数曲线。本文还给出了轧辊与轧件接触的速度分折方法,以此为基础可导出最佳辊型的优化设计方法以及轧机的合理运动参数的确定方法。三辊行星轧机的结构十分紧凑,因而三个轧辊干涉与否是辊型设计中一个必须解决的问题。本文在彻底弄清轧辊之间以及轧辊与轧件之间的几何关系的基础上,提出了一种精确的切片干涉检查方法。上述三部分内容均已编写成可供实际使用的电算程序,程序可在Apple-Ⅱ或IBM机上使用。 相似文献
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研究了减速机蜗杆零件滚轧成形过程中滚轧轮运动方式对成形的影响。首先根据蜗杆零件特点,设计了轴线平行的两滚轧轮滚轧方式,并确定了滚轧轮的具体结构参数。然后进行了蜗杆材料20Cr Mn Ti钢的热压缩实验,在应变速率分别为0.1,1,10和30 s~(-1),实验温度分别为800,900和1000℃的情况下,得到了材料的应力-应变曲线。最后通过数值模拟研究了蜗杆滚轧过程中两种滚轧轮运动方式的成形结果,并进行了实验验证。结果表明:当两个滚轧轮顺时针单向旋转时,数值模拟中工件轴向位移达到6.48 mm,实验件达到2.66 mm;当两个滚轧轮先顺时针、再逆时针往复旋转时,工件的轴向位移矢量和接近零。滚轧轮往复旋转的滚轧方式能够有效避免蜗杆工件轴线位移严重的问题,保证了滚轧的顺利进行。 相似文献
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This paper proposes a new approach to analyze the stability of a cutting process. Previously, most studies have generally assumed the work-piece to be rigid and have, therefore, ignored work-piece deformation. In analyzing, the stability of the cutting process, these studies simply considered the dynamic equation of the tool. However, in practice, the work-piece undergoes deformation as a result of the application of an external force by the cutting tool. This deformation changes the chip thickness and has an effect on the critical chip thickness. Consequently, this study proposes a novel stability analysis method for the turning process in which deformation of the work-piece is considered. The cutting, which takes place in the turning process, is described using partial differential equations, and a set of dynamic equations is developed by considering the interaction between the tool and the work-piece. Having performed Laplace transformation, the stability of the cutting system can be analyzed in terms of the work-piece length, radius, natural frequency, deflection, slenderness ratio, cutting point, and material. The relationship between the critical chip width and the cutter spindle speed is investigated under a range of cutting and work-piece conditions. The analytical results for the current flexible work-piece are compared with those for a rigid work-piece. It is found that the critical chip width of the flexible work-piece is always greater than that of the rigid body. 相似文献
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研究剥叶滚筒转速对采用弹簧剥叶元件的甘蔗剥叶机的影响。通过仿真分析得出:剥叶滚筒转速越快,剥叶元件对甘蔗的打击力越大,对剥叶越有利;剥叶滚筒转速越快,剥叶元件与甘蔗接触次数越多,越有利于剥叶。通过试验得出:剥叶滚筒转速越快其含杂率越低,剥叶效果越好,这一结论与仿真分析是一致的。 相似文献
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介绍用G50建立工件坐标系的原理、格式与含义,分析用G50建立坐标系的实际使用情况,并结合FANUC 0i系统,介绍用G50建立坐标系的常用方法,针对使用该方法时容易出现的问题提供了解决方案,总结了G50指令的特点及使用时的注意事项,并对如何灵活使用G50进行了阐述,为数控车床工件坐标系的建立提供了高效灵活的实用方法。 相似文献
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Impulse electromagnetic forming (IEMF) is an effective and powerful technique widely used for joining and shaping metals and field-shaper is a main part of the electromagnetic forming which has important effect on the distribution of magnetic field. In this technique, a metal work-piece is pushed to a die and formed by a pressure created using an intensive, transient magnetic field. This magnetic field is produced by passing a pulse of electric current through a forming coil in a pulsed power circuit. The produced transient magnetic field induces eddy currents in the surface of work-piece. Induced eddy currents in work-piece produce a magnetic field with reverse direction of initial magnetic field; this results in a mutual repulsion between coil and work-piece and in this way the work-piece is thrown toward the die. In this process created magnetic forces applied to work-piece are much like uniform, but in real applications, some regions of a work-piece have to be more deformed and therefore a much greater pressure has to be applied to these regions. The task of concentration of magnetic forces to some desired regions can be accomplished using field-shapers. Yu et al. [Yu, H., Li, C., Zhao, Z., Li, Z., 2005. Effects of field-shaper on magnetic pressure in electromagnetic forming. J. Mater. Process. Technol. 168, 245–249] have recently shown the effect of field-shaper on the distribution of the magnetic fields in electromagnetic forming, but because of the nature of 2D simulations some edge effects in real geometries could not be taken into consideration. In this paper, a 3D simulation using the FEA software MAXWELL has been applied to study the magnetic field distribution during an impulse electromagnetic forming process. Comparison of the 3D and 2D simulation results indicates that the maximum magnetic fields achieved in front of nodules of the field-shaper are about 15% stronger than those expected by 2D simulations.By changing the geometry of the field-shaper, the influence of the shape of the field-shaper on the distribution of the applied forces on the work-piece has been studied. Based on these simulations, some simple guidelines to design the field-shaper have been derived. 相似文献
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针对塑胶加工件成型过程中保温时间、注射压力与过程温度难于实施精确控制的问题,探讨了基于多模态控制的强鲁棒性策略。剖析了过程存在的控制难题,总结了过程的控制论特性,基于控制策略的对比研究,探讨了基于仿人智能的强鲁棒性控制策略,构造了塑胶加工件成形过程的多模态控制算法。以过程温度控制为例,仿真验证了提出的强鲁棒性控制策略的良好动静态控制品质。实验仿真结果表明:该强鲁棒性控制策略是合理可行的。 相似文献
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首次提出将斜轧钢球轧辊的转动与轧件的轴秘移动分开考虑,用画法几何中的图形变换法与微分几何中的包络法分别求出斜轧钢球轧辊轧形曲面的图解解与解析解。进一步分析结果表明,从理论上完整地描述斜轧钢球轧辊辊形曲面仅需要四个独立坐标。 相似文献