Countermeasure of the pattern formation phenomena generated on rolling contact systems

存在许多旋转机械系统，其中转子在转子的外周和与转子接触的其它系统之间的恒定压力的条件下旋转。伴随着系统本身的结构元件的变形，增长过程的发展成为强烈的振动，经常在机器中产生，使得连续操作不再可能。这种现象被称为花纹形成现象，作为发生这种现象的主体系统的例子，我们可以举出造纸机的压榨辊、纺织机的卷绕机、钢铁厂的轧机、钻头的切削孔、工具机的再生颤振、砂轮的多边形变形、钢轨的弯曲、铣削加工中的颤振现象。在机床领域中，花型形成现象的机理被广泛研究。然而，避免图案形成现象的对策尚未建立。在本研究中，通过改变辊的直径，并通过改变操作速度，以避免图案形成现象的对策进行了研究。从数值分析中发现，存在抑制斑图形成的最佳直径比，并且还发现，通过改变操作速度的对策对于降低斑图形成的增长速度是有效的。

There exist many rotatory machine systems in which a rotor is rotating under the condition of a constant pressure between outer circumference of the rotor and the other system being in contact with the rotor. Accompanying the deformation of the structure elements of the system itself, the development of the growth process into a strong vibration is often generated in the machine so that the continuous operation is not possible any more. This kind of phenomena is called pattern formation phenomena.As examples of the subject system in which such phenomena take place, we can give the press rolls in paper making machine, the winder of the textile machine, the rolling mill in the iron works, the drill cutting hole, regenerative chatter in the tool machine, the polygonal deformation of the grinding wheel, the corrugation of the rail, chattering in milling.In the field of machine tools, the mechanism of the pattern formation phenomena is widely investigated. However, the countermeasure to avoid the pattern formation phenomena has not been established. In this research, the countermeasure to avoid the pattern formation phenomena by changing the diameter of rolls, and by changing the operation speed is investigated. It was found from the numerical analysis that the optimum diameter ratio to suppress the pattern formation exists, and it was also found that the countermeasure by changing the operation speed is effective to decrease the growth speed of pattern formations.