Surround structure of speaker

1. A surround structure of a speaker, comprising:

an inner rim;

an outer rim; and

a wave-shaped elastic protrusion, disposed between the inner rim and the outer rim,

wherein the wave-shaped elastic protrusion is integrally formed by a plurality of arc-shaped parts surrounding each other, each arc-shaped part comprising:

a first end;

a second end; and

a middle part between the first end and the second end,

wherein a radial section of each arc-shaped part is arcuate and comprises two arc-shaped segments and a top edge located between the two arc-shaped segments, and

wherein a curvature of a radial section of each arc-shaped segment from the first end to the middle part gradually decreases, a curvature of a radial section of each arc-shaped segment from the middle part to the second end gradually increases, and a shape of a radial section of the first end is the same as a shape of a radial section of the second end.

2. The surround structure of a speaker according to claim 1 , wherein the top edges of the arc-shaped parts are located at same heights and are concyclic.

3. The surround structure of a speaker according to claim 1 , wherein each arc-shaped part comprises an inner arc edge and an outer arc edge, the inner arc edges of the arc-shaped parts are located at same heights and are concyclic, and the outer arc edges of the arc-shaped parts are located at same heights and are concyclic.

4. The surround structure of a speaker according to claim 1 , wherein each arc-shaped part is symmetrically disposed by using the middle part as a center.

5. The surround structure of a speaker according to claim 1 , wherein the radial section of the first end and the radial section of the second end are semicircular.

6. The surround structure of a speaker according to claim 1 , wherein the wave-shaped elastic protrusion is symmetrically disposed with respect to a reference plane, and the reference plane is coplanar with the first end or the second end of one of the arc-shaped parts.

7. The surround structure of a speaker according to claim 6 , wherein the wave-shaped elastic protrusion comprises an odd quantity of arc-shaped parts, and the reference plane is further coplanar with the middle part of another arc-shaped part.

8. The surround structure of a speaker according to claim 1 , wherein each arc-shaped segment comprises one first point on the first end and one second point on the second end, and

wherein the first point and the second point are located at same heights, and a connection line from the first point to the second point along a surface of the arc-shaped segment is a smooth curve.

9. The surround structure of a speaker according to claim 1 , wherein the radial section of the first end of each arc-shaped part comprises a first vertex and two first bottom end points, and a reference line is defined between the two first bottom end points, and

wherein a reference circle is defined according to the first vertex and a midpoint of the reference line, connection lines between the first vertex and the first bottom end points run through the reference circle to form intersection points, and a curvature of each arc-shaped segment in the middle part is defined according to an arc from the intersection point to the first vertex.

10. The surround structure of a speaker according to claim 1 , wherein each arc-shaped part comprises a plurality of first sampling points at positions of different heights on the first end and a plurality of second sampling points respectively corresponding to the plurality of first sampling points on the second end, the curvature of the radial section of each arc-shaped segment from the first end to the middle part and the curvature of the radial section from the middle part to the second end are defined according to respective connection lines between the plurality of first sampling points and the plurality of second sampling points.