Transformer
A pair of flanges 16 are formed on both ends of a spool 14 of a bobbin 12 , and an insulation layer 32 formed by heat curing an interlayer insulation prepreg tape 22 is formed on the external periphery of the spool 14 . A primary coil 26 is wound on the external periphery of the insulation layer 32 , and a secondary coil 28 is wound on the external periphery of the primary coil 26 . Insulation layers 32 are provided respectively between the primary coil 26 and the secondary coil 28 , and on the external periphery of the secondary coil 28 . Insulation layers 34 formed by heat curing an inner wall insulation prepreg tape 24 are provided on mutually opposed faces 16 A of the paired flanged 16 , and such insulations layers 32 and 34 have a mutually linked structure.
1. A transformer comprising:
a bobbin having a spool and a pair of flanges positioned on both ends of the spool;
two or more coils wound in superposition on the spool; and
an insulation layer formed by curing an insulation tape constituted of an epoxy resin coated on a support material, the insulation tape constituted of a prepreg tape in which an epoxy resin is coated on a surface of a polyester tape;
wherein the insulation tape is provided respectively on mutually opposed faces of the paired flanges and also respectively on an internal periphery and an external periphery of the two or more coils, and such insulation tapes are cured to constitute an insulation layer covering the two or more coils.
2. A transformer as claimed in claim 1 , wherein the insulation tape is constituted of a prepreg tape having a three-layered structure, in which an epoxy resin is coated on a surface of a polyester tape, and a tacky material is coated on the epoxy resin.
3. A transformer as claimed in claim 1 , wherein the insulation tape is constituted of a prepreg tape having a three-layered structure, in which an epoxy resin is coated on a surface of a polyester tape, and a tacky material is coated on the other surface of the polyester tape.
4. A transformer as claimed in claim 1 , wherein the polyester tape is a multilayered polyester film tape having at least two layers.
5. A transformer as claimed in claim 4 , wherein said multilayered polyester film tape has a three-layered structure.
6. A transformer as claimed in claim 1 , wherein the insulation tape provided respectively on the opposed faces of the paired flanges is constituted of a prepreg tape having a three-layered structure, in which an epoxy resin is coated on a surface of a polyester tape, and a tacky material is coated on the other surface of the polyester tape, and
the insulation tape provided respectively on the internal periphery and the external periphery of at least one of the two or more coils is constituted of a prepreg tape having a three-layered structure, in which an epoxy resin is coated on a surface of a polyester tape, and a tacky material is coated on the epoxy resin.
7. A transformer as claimed in claim 1 , wherein the insulation tapes are cured by heating for about 60 to 120 minutes at 120° C.