This disclosure relates to a diaphragm structure, and in particular to a diaphragm structure of a loudspeaker.
A loudspeaker is a transducer converting electric energy into sound energy. The sound energy generates sound to the surrounding in the form of radiation of sound waves, and the radiation of sound waves is mainly achieved by a diaphragm driving surrounding air media. A diaphragm is an important component of a loudspeaker, and generally includes an annular body and a surround disposed on an outer rim of the annular body.
Referring to
In addition, high-power loudspeakers often have larger vibration, and while the strength of the traditional diaphragm is sometimes insufficient to resist the vibration. Therefore, it is necessary to develop a diaphragm with high strength.
In view of this, this disclosure provides a diaphragm structure of a loudspeaker, including a surround and an annular body. The surround is annular and has an inner rim and an outer rim relative to the inner rim. The annular body disposed on the inner rim of the surround is integrally formed by a plurality of rigid reinforcing units arranged in a circle. Each rigid reinforcing unit includes a first side edge, a second side edge, and two third side edges connected to the first side edge and the second side edge. The two third side edges are located on opposite sides, and the first side edge and the second side edge are separately located on opposite sides. The two third side edges are formed by a plurality of first reference points at different height positions, and heights of the first reference points asymmetrically and gradually decrease from the middle towards the first side edge and the second side edge to form a substantially upward curve. A peak ridge line is defined between first reference points at the highest position of the two third side edges located on the opposite sides, and the peak ridge line is formed by a plurality of second reference points at different height positions, and heights of the second reference points symmetrically and gradually increase from the middle towards the two third side edges to form a substantially downward curve. All first side edges of the plurality of rigid reinforcing units at the same height position form an inner circle of the annular body, and all second side edges at the same height position form an outer circle of the annular body.
In an embodiment, the first reference points of the highest height position at the two third side edges are at the same height position.
In an embodiment, a plurality of normal lines is defined at positions perpendicular to the peak ridge line between the first side edge and the second side edge, and a curvature of each of the third side edges is greater than or equal to a curvature of each of the normal lines.
In an embodiment, the highest positions of the normal lines are intersections of the normal lines and the peak ridge line.
In an embodiment, each of the normal lines is formed by a plurality of third reference points at a plurality of different height positions, a normal line passing the lowest position of the peak ridge line is defined as a reference normal line, and a third reference point at the highest position of the reference normal line is a second reference point at the lowest position of the peak ridge line.
In an embodiment, each of the rigid reinforcing units comprises a first surface and a second surface connected to the first surface; the first surface is between the peak ridge line and the first side edge and between the two third side edges, and the second surface is between the peak ridge line and the second side edge and between the two third side edges, where a bent portion is formed between the first surface and the second surface.
In an embodiment, the height position of the second side edge is higher than a height position of the first side edge.
In an embodiment, the material of the annular body is aluminum. The aluminum material of the annular body has a density of 2700 kg/m3. The aluminum material of the annular body has a Young's modulus of 75 GPa. The aluminum material of the annular body has a Poisson's ratio of 0.33.
In summary, in the diaphragm structure of the loudspeaker according to this disclosure, positions of the first reference points of the third side edges gradually decrease from the highest point (the first reference points at the highest height position in the third side edges) towards a direction of the first side edge and a direction of the second edge; height positions of the second reference points of the peak ridge line gradually increase from the lowest point (the first reference points at the lowest height position of the peak ridge line) towards directions of the highest points at both ends (the first reference points at the highest position). Thus, each rigid reinforcing unit forms a bent portion between the first surface and the second surface (at the peak ridge line), and forms a downward curve and presents a saddle shape at the peak ridge line, and the rigid reinforcing units of the diaphragm structure can solve the stress concentration problem between the first surface and the second surface (at the peak ridge line) so as to improve the strength of the rigid reinforcing units and enhance vibration energy of the diaphragm, thereby effectively improving sensitivity of the loudspeaker and extending a service life of the diaphragm structure.
The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein:
Referring to
Referring to
The surround 20 is disposed on an outer circumference of the annular body 10. In some embodiments, as shown in
Referring to
As shown in
Referring to
In some embodiments, referring to
Each normal line is perpendicular to a peak ridge line, and each normal line is defined by a connecting line between one point of the first side edge and one point of the second side edge, where the connecting line is perpendicular to the peak ridge line and passes one of the second reference points. The normal lines 115 are formed by a plurality of third reference points P3 at different height positions (positions and numbers of the third reference points P3 shown in
In some embodiments, referring to
In some embodiments, referring to
In some embodiments, referring to
In addition, because the peak ridge line 114 is a downward curve, the bent portion between the first surface 31 and the second surface 32 need not be too sharp so as to solve the stress concentration problem between the first surface 31 and the second surface 32 (at the peak ridge line 114), thereby improving the strength of the rigid reinforcing unit 11. In some embodiments, each rigid reinforcing unit 11 substantially is a saddle shape. In some embodiments, the reference numeral P11 of each first reference point is at the highest height position in the rigid reinforcing unit 11.
The annular body 10 may be made of an aluminum material. Preferably, material parameters of the annular body 10 of this disclosure are shown in Table 1.
A modal analysis is performed to compare the strength of the annular body 10 of this disclosure and a conventional annular body (without rigid reinforcing units) having a uniform curvature. First five natural frequencies of the annular body 10 of this disclosure and of the traditional annular body (shown in
As can be seen from Table 2, the first five natural frequencies of the annular body 10 of this disclosure are higher than the first five natural frequencies of the conventional annular body. According to the following formula (1):
where n is an order, Kn is the nth modal stiffness, and Mn is the nth modal mass, when the thickness is same, because a total area of the annular body 10 of this disclosure is larger than that of the conventional annular body, the mass of the annular body 10 of this disclosure is greater than that of the conventional annular body. According to the above formula (1), the stiffness of the annular body 10 of this disclosure is greater than that of the conventional annular body.
Referring to
In summary, in the diaphragm structure of the loudspeaker according to this disclosure, height positions of the first reference points of the third side edges gradually decrease from the highest point (the first reference points at the highest height position in the third side edges) towards a direction of the first side edge and a direction of the second edge; height positions of the second reference points of the peak ridge line gradually increase from the lowest point (the first reference points at the lowest height position of the peak ridge line) towards directions of the highest points at both ends (the first reference points at the highest position). Thus, each rigid reinforcing unit forms a bent portion between the first surface and the second surface (at the peak ridge line), and forms a downward curve and presents a saddle shape at the peak ridge line, and the rigid reinforcing units of the diaphragm structure can solve the stress concentration problem between the first surface and the second surface (at the peak ridge line) so as to improve the strength of the rigid reinforcing units and enhance vibration energy of the diaphragm, thereby effectively improving sensitivity of the loudspeaker and extending a service life of the diaphragm structure.
Although this disclosure has been disclosed above with reference to an embodiment, this disclosure is not intended to be limited to this. Any person skilled in the art may make some variations and modifications without departing from the spirit and scope of this disclosure. Therefore, the protection scope of this disclosure is subject to the scope defined by the claims.
Number | Date | Country | |
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62681399 | Jun 2018 | US |