| 摘要 |
PURPOSE: To attain partial thickened parts by obtaining a sufficient compliance and selecting properly the thickness by a metallic die. CONSTITUTION: One end of plural movable arms 9b, 9c bridged between an inner circumferential frame 9A to which a voice coil bobbin is inserted and an outer circumferential frame 9B of almost elliptic shape engaged with a speaker frame 8 is supported to an outer circumferential frame 9B at a position less than 45 deg. from the major axis direction of the outer circumferential frame 9B. Furthermore, a positioning groove 9a is formed to the outer circumferential frame 9B and engaged with a positioning projection 8b formed to a hold step 8a of the speaker frame 8 to make positioning and a butterfly damper 9 is made of a resin and formed integrally by the injection forming. A compliance of the same degree as a circular damper having a radius in matching with the length of the moving arms 9b, 9c with respect to the outer circumferential frame 9B is obtained. Even in the case of the butterfly damper 9 of an elliptic shape having difficulty in the positioning because of axial symmetry, the positioning with respect to the speaker frame 8 is facilitated. |
