磁致伸缩微小驱动器驱动电磁线圈的设计研究

Electromagnetic Coil Design for Mini-Magnetostrictive Actuator

激励磁场强度对磁致伸缩驱动器驱动位移的大小具有决定作用。对于微小磁致伸缩驱动器 ,如何进行驱动线圈的整体设计 ,使小尺寸线圈产生较大磁场强度是本研究的主要目标。通过优选电磁线圈参数Gcoil确定线圈几何结构尺寸 ,并通过建立磁场强度Hcoil与电磁线圈的电流密度Jcoil进而与电磁线圈线径 之间的关系模型计算和优选电磁线圈线径来提高线圈电磁转化率 ,从而增大激励磁场强度是研究的具体方法。针对 7mm× 2 0mm的Terfenol D试样确定驱动线圈几何参数Gcoil=0 .17,线圈电流密度为最大时的线径 =1mm。 1mm线径的电磁线圈 ,经ANSYS计算 ,比线径为 0 .5mm线圈产生的磁化强度提高了 2 5 %

The displacement of a magnetostrictive actuator vitally depends on the intensity of the exciting magnetic fields. For a mini-actuator, the key point is how to enhance the intensity of magnetic excitation generated by a small magnetic coil whose size is strictly limited in a mini-housing. This paper focuses on how to optimize a cent-metric size electromagnetic coil both on its geometric dimension and on the wire′s diameter in order to improve the efficiency of electro-magnetic coupling and the current density applied in the coil. By the approaches of optimizing the coil′s geometric factor G_(coil)and establishing an arithmetic model for optimizing the wire′s diameter , a coil with higher electro-magnetic coupling efficiency could be achieved. For a 7 mm×20mm Terfenol-D rod, the driving coil′s geometry is settled with G_(coil)=0.17, and its wire′s optimized diameter is 1 mm. Finally, a FEA result derived from ANSYS shows that the 1 mm diameter wire′s solenoid improves its magnetizing capacity by 25% compared with the one of 0.5 mm-diameter.