PURPOSE: To avoid occurrence of cracks and separation at the time of hardening the molding resin by a coil wherein a bobbin integrally formed by crape insulating paper and the impregnated resin is disposed in the inner side of the coil.
CONSTITUTION: The axial direction of a core 1 is coincident with the direction of shrunk folds of a bobbin 2, which includes voids caused by the folds of crape insulating paper. The crape paper is formed of insulating paper endowed with shrunk folds. A wound-up coil 3 using this crape insulating paper as a bobbin is set in a mold such that the shrunk folds of the bobbin 2 extends in the longitudinal direction. After drying and degassing, the coil 3 is impregnated with liquid resin and then molding resin is injected round the coil 3. With this, a mold coil can be attained in which fine portions of the bobbin, coil 3 and main insulating layers are filled with the impregnated resin and coarse portions of them are filled with the molding resin. At this time, since the shrunk folds extends in the longitudinal direction, air bubbles can escape upwardly so that the resin impregnation is made thoroughly. In case of mixing filler powder such as silica or talc, the coil is first impregnated with liquid resin and then is molded with injected resin including such fillers.
| JP7161459 | Coil device |
| JP2011159577 | INSULATED ELECTRICAL WIRE AND ELECTRIC COIL AND MOTOR USING THE SAME |
TAKAHASHI TADASHI
OONISHI ISAO
OOTSUKA TAKASHI
TOSHIBA CHEM PROD