| 摘要 |
PURPOSE:To obtain a coil for a transformer having excellent dielectric strength by forming a clearance between sheet-shaped electric wires. CONSTITUTION:Sheet-shaped electric wires 1 and inter-layer insulating materials 4 wider than the width of electric wires inserted among the electric wires 1 are wound spirally to form a coil. For form clearances 3, the both end sections of the inter-layer insulating materials 4 are folded back, and the tip sections of the sheet-shaped electric wires are placed on the folded-back sections. Consequently, conductive foreign matters mixing among the sheet-shaped electric wires do not damage the inter-layer insulating materials 4 because of the clearances. The insulating materials of sections, which are in contact with the burrs of the tip sections of the sheet-shaped electric wires, are reinforced to the burrs. Accordingly, dielectric strength can be increased without inserting another insulating material by folding back the both ends of the inter-layer insulating materials. When the number of fold-back is increased, the clearances augment, and the dielectric strength increases only by a section corresponding to the augmentation of the clearances. |
