设计了相应的电磁力施加装置以实现对超细径光纤熔融拉伸力的精确控制。采用有限元法分析不同线圈参数下电磁线圈与永磁铁之间电磁力的大小, 获得电磁力与线圈各参数间的数学关系式。以拉伸系统性能要求及线圈骨架的外形尺寸为限制条件建立约束方程及目标函数进行优化求解, 得到最优参数。在依据优化参数制作电磁线圈的基础上设计了电磁力控制电路, 通过调节线圈电流精确控制电磁力。最后, 进行电磁力施加装置性能实验。实验结果表明: 光纤拉伸力的范围达到26.073 mN; 光纤拉伸力的分辨率达到7.473 μN, 满足超细径光纤熔融拉伸对拉伸力范围及分辨率的要求。

An electromagnetic force device is designed to realize the precise force control in the process of fusion stretching of ultra-thin fibers. First, the electromagnetic force with different coil parameters is calculated based on finite element method, and the relationship between electromagnetic force and coil parameters is derived. With the demand of stretching system performance and the dimension restrictions of the coil frame, constraint equations and objective functions are established to optimize the solution to machine the electromagnetic coil. Then the control circuit for electromagnetic force is designed to regulate the current in the coil and achieve the fine adjustment of electromagnetic force. Finally, experiments of electromagnetic force device are performed. The results indicate that the range of stretching force for the optical fibers can achieve 26.073 mN and the measuring resolution is 7.473 μN. It satisfies the demand of the fusion stretching of ultra-thin fibers.