| 摘要 |
PURPOSE:To suppress temperature rise of a magnetic circuit and prevent burn dependent upon heating of a coil by sealing gas such as high-heat conductivity and chemically stable helium into a space surrounding a voice coil. CONSTITUTION:Damper 1 is so constituted that air permeability may be prevented by sticking a thin film such as a rubber, and frame 2 is so structured that the space form damper adhesion part 9 to bottom yoke 3 of a magnetic circuit may be sealed. Gas injection unit 6 and exhaustion unit 7 are so provided that gas can be sealed into this sealed space from the external. Gas such as high-head conductivity and chemically stable helium is sealed in this sealed space. Thus, heat generated in the voice coil can be transferred to the outside of the magnetic circuit efficiently to prevent burning of the coil. |
