卧式离心滚磨介质运动分析及数值模拟

发布时间：2018-06-12 11:18

本文选题：离心滚磨 + 离散元仿真　；参考：《昆明理工大学》2017年硕士论文

【摘要】：表面光整加工技术作为绝大多数零件的最终加工工艺,对提高产品质量和延长零件及整机的使用寿命等具有十分重要的影响。离心滚磨中磨料颗粒运动的复杂性,导致了其加工参数确定上的困难,大大限制了其在高端市场中的应用。随着设备行业的快速发展,对光整加工技术提出了更高的要求。本文通过对滚筒宏观的运动过程进行分析,再结合离散元软件EDEM对滚磨光整加工过程中磨料的运动、磨料对工件的作用进行分析。本文以某型号的卧式离心滚磨设备为研究对象,从运动过程分析和参数化仿真两方面深入研究离心滚磨滚筒内混合介质的相对运动和碰撞过程。一方面运用理论分析离心滚磨光整的介质运动规律及介质群的分布特征,研究了工艺参数与结构参数的计算关系,并分析加工效率,加工质量与冲击能量的联系。另一方面,对比两种临界传动比的计算模型,运用EDEM软件对不同临界传动比进行仿真验证,探讨离心滚磨光整加工过程中传动比对磨料与工件间碰撞过程的影响。同时,运用EDEM对离心滚磨设备的两个重要结构参数,回转倾角和截面形状进行仿真,并结合离散元理论和能量模型从碰撞次数,冲击能量和碰撞力等方面进行对比研究。研究发现,当传动比在0.6和1.4这两临界点以内时,滚磨机内介质群的流动状态好,磨料和工件的碰撞次数较高,切向冲击能量占比高;超过或低于这两个临界传动比时,滚筒内的强制流动层不明显,加工效率不高,得出了第二种临界传动比的计算方法更优。同时得出了当回转倾角为10°时,滚筒内工件和磨料的碰撞次数最大,但是此时磨料与工件的相对碰撞速度,冲击能量较低,同时碰撞作用力也较小,不过此时碰撞作用较均匀,适合精磨。而对不同截面形状的滚筒进行仿真分析,得出正八边形截面的滚筒内,磨料和工件的相对碰撞速度和碰撞作用力最大,但是此时碰撞速度不均匀;而正六边形截面的滚筒内相对碰撞速度和作用力次之,但此时碰撞作用均匀,与实际生产中运用正六边形截面的滚筒相吻合。
[Abstract]:As the final processing technology of most parts, surface finishing technology plays an important role in improving the product quality and prolonging the service life of the parts and the whole machine. The complexity of abrasive particle movement in centrifugal roller mill leads to the difficulty in determining the processing parameters, which greatly limits its application in the high-end market. With the rapid development of equipment industry, higher requirements for finishing technology have been put forward. In this paper, the macroscopic motion process of the roller is analyzed, and the movement of the abrasive and the effect of the abrasive on the workpiece are analyzed in combination with the discrete element software EDEM. In this paper, the relative motion and collision process of the mixing medium in a centrifugal roller are studied from two aspects of motion process analysis and parametric simulation, taking a certain type of horizontal centrifugal roller mill equipment as the research object. On the one hand, the law of medium motion and the distribution characteristics of medium group of centrifugal rolling finishing are analyzed by using theory, the relationship between process parameters and structural parameters is studied, and the relationship between processing efficiency, machining quality and impact energy is analyzed. On the other hand, comparing the two calculation models of critical transmission ratio, using EDEM software to verify the different critical transmission ratio, the effect of transmission ratio on the collision process between abrasive and workpiece during centrifugal rolling finishing process is discussed. At the same time, EDEM is used to simulate two important structural parameters of centrifugal rolling mill, such as rotation angle and section shape, and the discrete element theory and energy model are used to compare the impact number, impact energy and impact force. It is found that when the transmission ratio is within 0.6 and 1.4, the flow state of the medium group in the roller mill is good, the number of collisions between the abrasive and the workpiece is higher, the tangential impact energy is high, and when the transmission ratio exceeds or falls below these two critical transmission ratios, The forced flow layer in the drum is not obvious and the machining efficiency is not high, so the calculation method of the second critical transmission ratio is better. At the same time, when the angle of rotation is 10 掳, the impact times of workpiece and abrasive in the cylinder are the largest, but the relative impact velocity of abrasive and workpiece is lower, the impact energy is lower, and the impact force is smaller, but the impact action is more uniform at this time. Suitable for grinding. The results show that the relative impact velocity and impact force of abrasive and workpiece are the largest in the cylinder with normal octagonal section, but the impact velocity is not uniform at this time. The relative impact velocity and force in the cylinder of hexagonal section are the second, but the impact action is uniform, which is consistent with the cylinder with hexagonal cross section in actual production.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG580.6

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