JP2000184492A - Diaphragm for loudspeaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm for loudspeaker which is strengthened while its superior sound quality is maintained. SOLUTION: On the surface of a diaphragm 10 for loudspeaker, twenty-one radial lines 11 which are arranged at prescribed angular intervals in the circumferential direction and three circumferential lines 12 concentrically arranged in the radial direction are formed. On the surface of the diaphragm 10, plural partially spheric recessed sections 13a, 13b, and 13c are formed in such a way that the centers of their circular openings 14 are positioned at the intersections of the radial lines 11 and circumferential lines 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm for a speaker device such as audio equipment, and more particularly to a diaphragm for a speaker having a reinforced structure.

[0002]

FIG. 3 is a front view of a conventional speaker diaphragm 30. As shown in FIG. The conical speaker diaphragm 30 has, for example, five raised ribs 31 on the surface side at equal angular intervals in the circumferential direction in order to increase the strength. 4 and 5 are cross-sectional views taken along lines IV-IV and VV of FIG. 3, respectively. FIG.
, The left side and the right side correspond to the center side and the peripheral side of the speaker diaphragm 30, and the upper side and the lower side correspond to the front side and the back side, respectively. In the raised rib 31, both side edges in the circumferential direction of the speaker diaphragm 30 are corners 32.

[0003]

The problems of the conventional speaker diaphragm 30 are as follows. (A) On the surface of the loudspeaker diaphragm 30, during the period in which the center of the loudspeaker diaphragm 30 is displaced forward, the loudspeaker diaphragm
The air flows from the periphery to the center of the 30, that is, inward in the radial direction. The raised ribs 31 act as a resistance to the flow of the air and affect the sound quality. (B) The same raised ribs 31 only exist at equal angular intervals in the circumferential direction, and the effect of increasing strength is small. (C) The presence of the corners 32 on both sides in the width direction of the raised rib 31
This may be an obstacle to the sound of the raised rib 31 trying to spread in the width direction.

[0004]

According to the speaker diaphragm (10) of the present invention, a plurality of partial spherical recesses (1) are formed on the front side.
3a, 13b, 13c) are distributed in the radial direction and the circumferential direction.

The speaker diaphragm (10) is reinforced by the existence of partially spherical recesses (13a, 13b, 13c) distributed in the radial direction and the circumferential direction in the speaker diaphragm (10). Since the partial spherical recesses (13a, 13b, 13c) are present as recesses on the surface side of the speaker diaphragm (10), the surface of the speaker diaphragm (10) is smaller than when they exist as protrusions. This greatly reduces the effect of the airflow resistance on the air flow and prevents sound quality from deteriorating.

According to the loudspeaker diaphragm 10 of the present invention, the partial spherical recesses (13a, 13b, 13c) are formed in an odd number, preferably three rows, in the radial direction.

[0007] The partial spherical recesses (13a, 13b, 13c) are an odd number of rows in the radial direction.
The arrangement of (13a, 13b, 13c) is not limited on the same radiation (11). Radiation such as staggered footprint for radiation (11)
They may be arranged with some deviation from (11). When the speaker diaphragm (10) causes split vibration in the radial direction, the split vibration is an even-number split in the radial direction. However, the partial spherical recesses (13a, 13b, 13c) are odd-numbered, preferably three in the radial direction, so that even-numbered splitting is suppressed, and as a result, splitting vibrations in the radial direction due to resonance are reduced. Can be suppressed.

According to the speaker diaphragm (10) of the present invention, the radially outward partial spherical recesses (13a, 13b, 13c)
The diameter of the opening (14) is increased.

[0009] The area of the speaker diaphragm (10) per equal center angle increases in the radial direction from the center to the periphery, and the partial spherical recesses (13a, 13b, 13c) are increased in accordance with the increase in the area.
Since the diameter of the opening (14) is increased, appropriate strength can be maintained by the appropriate number of partial spherical recesses (13a, 13b, 13c) having a large opening (14). In addition, partial spherical recesses (13a, 13
(b, 13c), while keeping the diameter of the opening equal, there is also a method of increasing the number of partial spherical recesses (13a, 13b, 13c) toward the outer part in the radial direction, but the rib effect increases as the outer circumference increases It is not obtained very much and is disadvantageous in sound quality.

According to the speaker diaphragm (10) of the present invention, the partial spherical recesses (13a, 13b, 13c) are formed as an odd number, preferably 21 rows, in the circumferential direction.

The partial spherical recesses (13a, 13b, 13c) form an odd number of rows in the circumferential direction.
The arrangement of (13a, 13b, 13c) is not limited on the same circumferential line (12). Circumferential line, such as a zigzag foot around the circumferential line (12)
They may be arranged with some deviation from (12). When the speaker diaphragm (10) generates a divided vibration in the circumferential direction, the divided vibration is divided into even numbers in the circumferential direction. However, the partial spherical recesses (13a, 13b, 13c) are odd-numbered, preferably 21 in the circumferential direction, so that even-numbered division is suppressed, and as a result, division in the circumferential direction due to resonance occurs. Vibration can be suppressed.

According to the speaker diaphragm (10) of the present invention, an odd number of partial spherical recesses (13a, 13b, 13c) in the circumferential direction are provided.
Is a group of an odd number, preferably three, in the circumferential direction (16a, 1
6b, 16c), the central angles occupied by each group (16a, 16b, 16c) are set equal, and the groups (16a, 16b, 16c) adjacent in the circumferential direction
Between the partial spherical recesses (13a, 13
b, 13c), the angular interval a2 between the centers of the openings (14) is
a, 16b, 16c) and the circumferentially adjacent partial spherical recesses (13a, 1c)
3b, 13c) is larger than the angular interval a1 between the centers of the openings (14).

[0013] Between the groups (16a, 16b, 16c) in the circumferential direction, there is an appropriately poor range of partial spherical recesses (13a, 13b, 13c), that is, a range in which the strength is slightly reduced. When the speaker diaphragm (10) generates a divided vibration in the circumferential direction, it easily becomes a node of vibration. However, the divided vibration of the speaker diaphragm (10) due to the resonance in the circumferential direction is an even-number division, whereas the portion that is likely to be a node is the speaker diaphragm (1).
Since the number is 0 at equal angular intervals in the circumferential direction of (0),
Divided vibration of the speaker diaphragm (10) in the circumferential direction is prevented.

According to the speaker diaphragm 10 of the present invention, the angular interval a2 is set to 1.5 to 3 times, preferably 2 times the angular interval a1.

According to the speaker diaphragm (10) of the present invention, in the depth range (17) of the partial spherical recesses (13a, 13b, 13c),
The thickness of the partial spherical recesses (13a, 13b, 13c) is increased more than other areas (18).

The partial spherical recesses (13a, 13b, 13c)
Although resonance is most likely to occur in (17), this can be avoided by increasing the wall thickness in the deeper range (17), and sound quality can be improved.

According to the speaker diaphragm (10) of the present invention, the depth range (17) of the partial spherical recesses (13a, 13b, 13c) is the same as that of the partial spherical recesses (13a, 13b, 13c). A concave portion (19) is formed on the inner surface of the partial spherical concave portion (13a, 13b, 13c) while making the thickness equal to the range (18).

The partial spherical recesses (13a, 13b, 13c)
Although resonance is most likely to occur in (17), the predetermined rigidity is imparted by the concave portion (19), so that such resonance can be avoided and the sound quality can be improved.

According to the speaker diaphragm (10) of the present invention, the speaker diaphragm is made of an injection-molded product of polypropylene.

By forming the speaker diaphragm (10) by injection molding of polypropylene, the partial spherical recesses (13a, 13b, 1) are formed.
Accurate control of the thickness of 3c) (particularly, the thickness of the back area (17)) becomes possible, and the sound quality can be improved. Further, if a colorant is mixed with the resin at the time of molding, the color can be changed every moment during the operation of the speaker diaphragm (10).

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a speaker diaphragm 10. The speaker diaphragm 10 has a bowl shape, and the center of the speaker diaphragm 10 is recessed from the periphery as viewed from the front side. The speaker diaphragm 10 is also made of an injection-molded product of polypropylene. Radiation 11 and circumferential line 12
Is only written in FIG. 1 to explain the positions of the partial spherical recesses 13a, 13b, 13c, but is not actually formed on the speaker diaphragm 10. Total 21
The radiation 11 extends radially from the center of the speaker diaphragm 10, and forms three groups 16a, 16b, 16c for every seven continuous radiation in the circumferential direction. In each of the groups 16a, 16b, and 16c, the angular interval a1 of the radiation 11 is 15 °, and the angular interval a2 between the closest radiations 11 between the circumferentially adjacent groups 16a, 16b, and 16c is 30 °. A2 is 1.5 to 3 times, preferably 2 times, a1. The three circumferential lines 12 are arranged concentrically, and the interval between the innermost circumferential line 12 and the central circumferential line 12 and the interval between the central circumferential line 12 and the outermost line are set to be equal. The partial spherical recesses 13a, 13b, and 13c open to the surface of the loudspeaker diaphragm 10 at the circular openings 14, and the center of each circular opening 14 corresponds to each radiation 11 and each circumferential line 12
Is the intersection with The diameter of the circular opening 14 is larger than that of the radially outer partial spherical recesses 13a, 13b, 13c. The partial spherical recesses 13a, 13b, 13c are divided into three groups 16a, 16b, 16c according to the grouping of the radiation 11 to which they belong.

As an example of the dimensions of the speaker diaphragm 10, the diameter of the speaker diaphragm 10 is 30 cm, and the diameter of the circular opening 14 of the partial spherical recesses 13a, 13b, 13c (unit: m)
m) are φ8, φ11, and φ14, respectively.

FIG. 2 shows a predetermined radiation of the speaker diaphragm 10.
FIG. 11 is a cross-sectional view along 11. 2, the left and right correspond to the center side and the peripheral side in the radiation direction of the speaker diaphragm 10, respectively, and the upper and lower correspond to the front side and the back side of the speaker diaphragm 10, respectively. The diameter of the circular opening 14 increases in the order of the partial spherical recesses 13a, 13b, 13c, and the depth also increases in the order of the partial spherical recesses 13a, 13b, 13c. The solid angles formed by the partial spherical surfaces of the partial spherical concave portions 13a, 13b, and 13c with respect to the center of the spherical surface become smaller in the order of the partial spherical concave portions 13a, 13b, and 13c. That is, the radially outward partial spherical recess
13a, 13b and 13c, the diameter of the circular opening 14 is increased, but the depth of the partial spherical recesses 13a, 13b and 13c is
For the diameter increase of 4, it is not deepened. The deep range (including the deepest portion) 17 of the partial spherical recesses 13a, 13b, 13c is
Swells to the back side of speaker diaphragm 10 and partially spherical recess 13
The wall thickness is larger than that of the opening side area 18 as the area excluding the deep area 17 in a, 13b, 13c.

FIG. 6 is a cross-sectional view of a modification of the structure of the back area 17 in FIG. In the partial spherical recesses 13a, 13b, and 13c of FIG. 6, the wall thickness is equalized in both the deep region 17 and the opening-side region 18, while the deep region 17 protrudes to the rear side, and the partial spherical recess 13
The inner surfaces of a, 13b, and 13c are recessed portions 19 in the back region 17. With such a cross-sectional structure, the rigidity of the inner region 17 is enhanced.

As shown in FIG. 2, the partial spherical recesses 13a, 13b and 13c are formed on the front side of the diaphragm 10 for a speaker.
It exists not as a convex part but as a concave part, and
Although the partial spherical recesses 13a, 13b, and 13c leave slight corners near the boundary with the surface main body of the speaker diaphragm 10, they have extremely small resistance to air flowing on the surface of the speaker diaphragm 10. Become. When the center of the speaker diaphragm 10 is displaced forward during the operation of the speaker diaphragm 10, air flows from the periphery to the center of the speaker diaphragm 10 in the radial direction on the front side of the speaker diaphragm 10. At this time, the resistance received from the partial spherical recesses 13a, 13b, 13c is suppressed, and high sound quality is maintained. Also, especially regarding the spread of the sound from the speaker diaphragm 10 in the left-right direction, the partial spherical recess 13
Since a, 13b, and 13c have low resistance, good sound quality can be provided to the user.

The resonance of the loudspeaker diaphragm 10 is divided into an even number in the radial direction, but due to the odd number of partial spherical recesses 13a, 13b, 13c in the radiating direction in the loudspeaker diaphragm 10, the resonance in the radial direction is caused. The resonance of the speaker diaphragm 10 is suppressed. Further, the partial spherical recesses 13a, 13b, 13c are divided into three groups 16a, 16b, 16c occupying equal central angles, and a2 is a1
Set to a larger value, the circumferential groups 16a, 16b, 16
In the boundary part of c, the strength of the speaker diaphragm 10 is made weaker than in the groups 16a, 16b and 16c. When the speaker diaphragm 10 resonates in the circumferential direction, the groups 16a, 16
Since the boundary between b and 16c tends to be a node of vibration, and the resonance of the speaker diaphragm 10 in the circumferential direction is an even number, the resonance of the speaker diaphragm 10 in the circumferential direction is Is suppressed. Furthermore, in each group 16a, 16b, 16c, the partial spherical recess 1
Since 3a, 13b, and 13c are an odd number of seven pieces in the circumferential direction, the divided vibration in the circumferential direction in each of the groups 16a, 16b, and 16c is also suppressed. Although there is a possibility of resonance at each of the partial spherical recesses 13a, 13b, and 13c, the resonance of each of the partial spherical recesses 13a, 13b, and 13c is suppressed by increasing the thickness of the depth range 17.
The circumferential length of the speaker diaphragm 10 increases in the radially outer portion, but the outer partial spherical recess 13 increases.
The diameter of the circular opening 14 is increased as a, 13b, 13c, and the strength of the portion is secured while suppressing an increase in the number of the partial spherical recesses 13a, 13b, 13c.

The partial spherical recesses 13a, 13b, 13c
7 is most likely to resonate, but the wall thickness is increased in the inner part 17 (FIG. 2) or
Is given a predetermined rigidity to avoid such resonance,
Sound quality can be improved.

By making the speaker diaphragm 10 an injection-molded product of polypropylene mixed with a coloring agent, the color of the speaker diaphragm 10 can be changed every moment during the operation of the speaker diaphragm 10.

[Brief description of the drawings]

FIG. 1 is a front view of a speaker diaphragm.

FIG. 2 is a cross-sectional view of the speaker diaphragm along a predetermined radiation.

FIG. 3 is a front view of a conventional speaker diaphragm.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along the line VV of FIG. 3;

FIG. 6 is a cross-sectional view of a modified example of the structure in the back area of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Speaker diaphragm 11 Radiation 12 Circumferential line 13a, 13b, 13c Partially spherical concave part 14 Circular opening part (opening part) 16a, 16b, 16c Group 17 Back part area 19 Concave part

Claims (9)

[Claims] 1. A plurality of partial spherical recesses (13a, 1
3b, 13c) are distributed in the radial direction and the circumferential direction. 2. The diaphragm for a speaker according to claim 1, wherein the partial spherical recesses (13a, 13b, 13c) are formed as an odd number, preferably three, rows in the radial direction. 3. Partially spherical recesses (13a, 13
3. The diaphragm for a loudspeaker according to claim 1, wherein the diameter of the opening (14) is made larger as the distance becomes larger. 4. The method according to claim 1, wherein the partial spherical recesses are formed as an odd number, preferably 21 rows, in the circumferential direction. The diaphragm for a speaker as described in the above. 5. An odd number of partial spherical recesses (13) in the circumferential direction.
The rows of (a, 13b, 13c) are circumferentially divided into an odd number, preferably three groups (16a, 16b, 16c), and the central angles occupied by each group (16a, 16b, 16c) are set equal. , Circumferentially adjacent groups (16
a, 16b, 16c), the angular interval a2 between the centers of the openings (14) of the partial spherical recesses (13a, 13b, 13c) closest in the circumferential direction.
Is the angular interval a between the centers of the openings (14) of the circumferentially adjacent partial spherical recesses (13a, 13b, 13c) in the group (16a, 16b, 16c).
The diaphragm for a speaker according to claim 4, wherein the diaphragm is larger than 1. 6. The diaphragm for a speaker according to claim 5, wherein the angular interval a2 is 1.5 to 3 times, preferably 2 times, the angular interval a1. 7. The inner part of the partial spherical recess (13a, 13b, 13c) has a greater thickness than the other part (18) of the partial spherical recess (13a, 13b, 13c). The speaker diaphragm according to any one of claims 1 to 6, wherein: 8. The depth range (17) of the partial spherical recesses (13a, 13b, 13c) is equal in thickness to other ranges (18) in the partial spherical recesses (13a, 13b, 13c). While the partial spherical recess
The diaphragm for a speaker according to any one of claims 1 to 6, wherein a recess (19) is formed with respect to an inner surface of the (13a, 13b, 13c). 9. The speaker diaphragm according to claim 1, wherein the diaphragm is made of an injection-molded product of polypropylene.