Electromagnetic conversion device using the same and butterfly damper

摘要

PROBLEM TO BE SOLVED: To allow the electromagnetic transducer to be adaptable for many kinds of vehicles by obtaining a resonance frequency characteristic with a smaller Q and to prevent production of unpleasant rattle noise by limiting a maximum value of the resonance frequency specific to the kind of material. ;SOLUTION: The butterfly damper A comprises an inner race a1, an outer race a2, a plurality of legs a3 (thin leg), a4 (thick leg), a5 (thin leg) and a6 (thick leg) connecting the inner race a1 and the outer race a2, and a plurality of the legs consist of combinations of different shaped legs. The butterfly damper A can suitably be used for the electromagnetic transducer that consists of a center pole, a voice coil directly wound on the center pole, the damper (butterfly damper A) fixed to an upper part and a lower part of the center pole, a magnet and a plate supported at an outer circumferential part of the damper and placed in the vicinity of the voice coil and a mounting metallic fixture fixed to the center pole and placed at a prescribed resonance point.;COPYRIGHT: (C)2000,JPO