The speaker has a frame, a magnetic circuit, a voice coil body and a diaphragm. The magnetic circuit is disposed inside of the frame to form a magnetic gap. The voice coil body is disposed movably in the magnetic gap. The diaphragm is coupled to the voice coil body by an inner periphery edge thereof and to the frame by an outer periphery edge thereof. The outer peripheral surface of a convex portion provided on a bottom of the frame is at least either being brought into contact with or in proximity to the magnetic circuit. The configuration can provide the speaker with excellent heat dissipation characteristics.
1. A speaker, comprising:
a frame including a frame bottom and a convex portion extending upwardly from said frame bottom, said convex portion being open at a top end to form a through-hole in said frame;
a magnetic circuit having a magnetic gap, said magnetic circuit being disposed inside of said frame;
a voice coil body disposed movably in said magnetic gap; and
a diaphragm having an inner periphery edge and an outer periphery edge, said inner periphery edge being coupled to said voice coil body and said outer periphery edge being coupled to said frame,
wherein said magnetic circuit includes a magnet and a yoke supporting said magnet, said yoke having a sidewall portion and a flange portion extending radially outward from said sidewall portion, said sidewall portion of said yoke contacting said convex portion of said frame and said flange portion of said yoke contacting said frame bottom of said frame so as to dissipate heat from said magnetic circuit to said frame.
2. The speaker of claim 1 ,
wherein said convex portion is constituted by a bent bottom part of said frame.
3. The speaker of claim 1 , further comprising:
a dust-proof net covering said through-hole in said frame.
4. The speaker of claim 3 ,
wherein said dust-proof net is formed of a flexible member.
5. The speaker of claim 4 ,
wherein said flexible member is formed of a metal having a low hardness.
6. The speaker of claim 4 ,
wherein said flexible member is formed of a metal having a high thermal conductivity.
7. The speaker of claim 4 ,
wherein said flexible member is formed of aluminum.
8. The speaker of claim 1 ,
wherein said magnetic circuit has a circuit through-hole, and
the speaker further comprises a dust-proof net disposed so as to cover a top end of said circuit through-hole.
9. The speaker of claim 1 , further comprising:
a suspension-holder having one end coupled to said frame and another end coupled to a back surface of said diaphragm.
10. The speaker of claim 1 ,
wherein said sidewall portion is cylindrical.
11. The speaker of claim 1 ,
wherein said convex portion is in contact with said magnetic circuit at a junction formed between said sidewall portion and said flange portion.
12. The speaker of claim 1 , wherein said frame comprises an outer wall disposed radially outwardly of said convex portion and extending upwardly from said frame bottom to a frame top supporting said diaphragm, and wherein said outer wall, said frame bottom, and said convex portion are integrally formed so as to maximize heat dissipation from said magnetic circuit to said frame.