| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that a case is made of plastic, the side wall is thick, and mass of a weight is difficult to be secured. <P>SOLUTION: A vibration body is provided with a bowl-like yoke 2, a magnetic circuit portion 1 composed of a plate-like magnet 3 sequentially laminated inside the yoke 2 and a top plate 4, a voice coil 5 arranged within a gap "g" formed between an inner radius of a side wall of the yoke 2 of the magnetic circuit portion 1 and an outer radius of the top plate 4, a vibration plate 8 which holds the voice coil 5 outside the magnetic circuit portion 1, and a ring-like weight 10 fixed to the outer radius of the yoke 2. A case 6 outside the magnetic circuit portion 1 is a metal member. A suspension 9 is integrally formed on a tube-like side wall portion 6a and its bottom portion, and the bottom of the suspension 9 fixes the yoke 2. The tube-like side wall portion 6a of the case 6 is formed thin, a storing capacity of the weight 10 is extended, the volume of the weight can be increased, and a vibration value can be improved. Also, an insert mold is not required, thereby enabling parts and a mounting cost to be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT |
