平板件电磁成形用线圈的设计

通过对线圈产生的磁感应强度的推导，并结合实验结果分析，得出线圈形状选择时遵循的原则：长形工件采用椭圆形线圈要优于圆形线圈，中心部位变形要求较高的工件应尽可能采用圆形线圈。通过对平板件上电磁力分布特点的分析，确定在成形特定尺寸的工件时，存在一个最小线圈尺寸，若线圈最外圈尺寸小于该尺寸，则工件边缘部分所受磁场力垂直向上，不利于工件的变形。从设备能量利用率的角度进行分析，得出在设备能量相同的情况下，板料厚度等于趋肤深度时，设备能量利用率最高，板料变形程度最大。在设备电容确定的情况下，可以通过改变线圈导线的材料、规格、线圈的匝数、匝间距等获得最高的设备能量利用率．

Design of Working Coil Used for Sheet Metal Electromagnetic Forming

By the deduction of the distribution of magnetic induction intensity induced by intense winding conductor plane coil, combined with the experimental results, the selection principles of the working coil shape is achieved, that was, for the long workpiece, elliptic coil is more suitable than circular coil, and for the workpiece that has much demand for the deformation of its center area, circular coil should be selected. By the analysis of distribution of the electromagnetic pressure on the sheet metal, it is proposed that a minimum working coil size is existed when a workpiece is formed. If working coil size is smaller than the minimum size, the direction of electromagnetic pressure at the edge of the sheet metal will be upward, and it is disadvantageous to the deformation of the sheet metal. It is acquired that in the cases where all of other forming conditions are the same, the equipment energy utility efficiency and deformation heights of the workpieces are both maximum when the sheet metal thickness is equal to skin depth. And the maximum equipment energy utility efficiency can be acquired by modification of working coil conductor material, size, windings, and winding space when the equipment capacitance is determinate.