JP7126763B2 - speaker - Google Patents

Description

The present invention relates to a speaker in which a plurality of cover portions having a plurality of openings are provided in front of the diaphragm in the direction of sound generation.

Patent Document 1 describes an invention relating to a speaker grill.
The speaker grill of the first invention described in Patent Document 1, as shown in FIG. is ensured, and good speaker acoustic characteristics can be obtained. The second invention described in Patent Document 1 is, as shown in FIG. can be reduced and the strength can be improved. A third aspect of the present invention is to secure both acoustic characteristics and strength characteristics by providing sound holes with non-uniform aperture ratios in the front face of the speaker.

Patent Document 2 describes an invention relating to a speaker protection device.
In this protective device, a protective net made of wires is provided in front of the diaphragm, and the protective net is composed of two or more kinds of metal wires having different internal losses. As a result, the function of protecting the diaphragm is sufficiently fulfilled, and the characteristic sound is hardly added.

JP-A-2003-37883 Japanese Utility Model Publication No. 6-25112

The inventions described in Patent Documents 1 and 2 are inferior in terms of dustproofness and waterproofness because they have a structure in which a single layer of speaker grill and protective net are provided in front of the diaphragm. It is not suitable for use in places where there is a high possibility of dust and moisture adhering to it, such as when it is attached to a vehicle body.

In FIG. 4 of Patent Document 1, as a second invention, an acoustic tube that is long in the front-rear direction is provided in front of the diaphragm, a rib is provided inside the acoustic tube according to the shape of the hole, and the length of the rib is varied. A structure approximating the length of an acoustic tube is described. With this structure, it is possible to improve dustproofness and waterproofness to some extent. However, since long holes partitioned by ribs are formed inside the acoustic tube, resonance is likely to occur within the holes. Resonance and interference increase at specific frequencies of the pressure, peak dips are likely to be formed, and there is a risk of generating large noise.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the conventional problems described above, and to provide a speaker that is excellent in dustproofness and waterproofness, and that has a structure capable of suppressing superimposition of noise on sound pressure.

The present invention provides a speaker provided with a magnetic circuit section including a magnet, a coil on which a magnetic field generated by the magnetic circuit section acts, and a diaphragm that vibrates together with the coil,
A plurality of cover portions are arranged in front of the diaphragm in the direction of sound generation, and each of the cover portions is provided with a plurality of openings and a plurality of partitions for partitioning the openings,
A space is formed between a front cover portion located farthest forward in the direction of sound generation and a rear cover portion located behind it,
The front cover portion has a convex portion and a concave portion, and the width dimension of the space portion in the direction of sound generation is made uneven.

In the speaker of the present invention, it is preferable that the opening and the partition are misaligned in a direction intersecting with the direction of sound generation between the covers located in the front and rear.

In the loudspeaker of the present invention, the width dimension of the space is continuously changed in the direction intersecting with the direction of sound generation.

For example, it is preferable that the width dimension of the space appearing in a cross section including the center line extending in the direction of sound generation passing through the diaphragm changes curvilinearly in the direction intersecting the center line.

In the speaker of the present invention, it is preferable that the convex portion and the concave portion are formed in an annular shape centering on the center line.

In this case, it is preferable that the width of the space in the direction of sound generation is narrow at the concave portion and wide at the convex portion.

In the speaker of the present invention, since a plurality of cover portions having a plurality of openings are provided in front of the diaphragm in the direction of sound generation, dust resistance and water resistance can be enhanced. In addition, the space between the front and rear covers has a non-uniform width dimension in the direction of sound generation, and the width dimension differs from place to place. It is possible to disperse, suppress the occurrence of peak dips, and reduce noise.

1 is a perspective view showing the appearance of a speaker according to an embodiment of the present invention; A perspective view showing a cross-sectional shape of the speaker shown in FIG. A partial cross-sectional view showing the cross-sectional part of the speaker shown in FIG. 2 from the front, A partial cross-sectional view showing only the front cover portion and the rear cover portion in the partial cross-sectional view of FIG. A partial cross-sectional view showing a speaker according to another embodiment of the present invention,

The speaker 1 according to the embodiment of the present invention shown in FIGS. 1 to 4 is for vehicle use, and is suitable for usage environments where dust and moisture are likely to adhere. The Y1 direction of the loudspeaker 1 is the front in the direction of sound generation, and the Y2 direction is the rear. 1, 3 and 4 show a center line O extending in the direction of sound generation.

A speaker 1 has a case 2 . Case 2 is separated into front case 3 and rear case 4 . As shown in FIG. 2, the rear end portion of the front case 3 and the front end portion of the rear case 4 are fitted together, and the front case 3 and the rear case 4 are connected by the uneven fitting portions 5 provided at a plurality of locations. are fixed to each other. The front case 3 and the rear case 4 are formed by injection molding using a synthetic resin material or die-casting using a light metal material.

As shown in FIGS. 2 and 3, a bracket 6 is provided inside the front case 3 . The bracket 6 is made of a non-magnetic or magnetic metal plate, and its upper end 6a is fixed to the front case 3. As shown in FIG. A support plate portion 6b perpendicular to the center line O is formed at the lower portion of the bracket 6, and the magnetic circuit portion 10 is fixed to the lower surface of the support plate portion 6b. The magnetic circuit section 10 is composed of a magnet 11, a lower yoke 12 to which the lower surface of the magnet 11 is joined, and an upper yoke 13 to which the upper surface of the magnet 11 is joined. is adhered and fixed to the lower surface of the support plate portion 6b. The lower yoke 12 and the upper yoke 13 are made of magnetic material. A center pole portion 12a projecting forward (in the Y1 direction) is formed integrally with the central portion of the lower yoke 12, and the outer peripheral surface of the center pole portion 12a and the inner peripheral surface of the ring-shaped upper yoke 13 are formed integrally. A magnetic gap G is formed therebetween.

A diaphragm 15 is provided in front of the magnetic circuit section 10 (Y1 direction). The diaphragm 15 is cone-shaped, and its outer peripheral portion 15 a is bonded and fixed to the bracket 6 by an edge member 16 . The outer peripheral surface of the bobbin 17 is adhered and fixed to the inner peripheral portion 15 b of the diaphragm 15 . A damper 19 having a corrugated cross section is provided between the outer peripheral surface of the bobbin 17 and the bracket 6 . The center line O passes through the center of the damper 19 . The elastic deformation of the edge member 16 and the damper 19 allows the cone-shaped diaphragm 15 to vibrate in the front-rear direction (Y1-Y2 direction). A voice coil 18 is wound around the lower end of the bobbin 17 and positioned within the magnetic gap G.

As shown in FIG. 2, inside the rear case 4, a circuit board 8 on which electronic components are mounted and other members are accommodated.

As shown in FIGS. 2 and 3, the front portion of the front case 3 is integrally formed with a cover structure portion 20 facing forward in the direction of sound generation by the vibration of the diaphragm 15 . The cover structure portion 20 is provided with a plurality of cover portions spaced apart in the direction of sound generation. In the embodiment, the cover structure 20 is provided with two cover portions, a front cover portion 21 and a rear cover portion 22, with a space portion C interposed therebetween. In addition, in the cover structure part 20, three or more cover parts may be provided via a space part.

As shown in FIGS. 1 and 2, the front cover portion 21 and the rear cover portion 22 have openings and partitions of a so-called grill structure. The front cover portion 21 is formed with a plurality of openings 24 and a partition portion 23 for partitioning the respective openings 24. As shown in FIG. 3, the rear cover portion 22 is also formed with a plurality of openings 26. A partition portion 25 is formed to partition the opening portion 26 of the . The opening 24 of the front cover part 21 and the opening 26 of the rear cover part 22 are rectangular through holes with long sides extending in the X1 direction, and are arranged parallel to each other. The partition portion 23 of the front cover portion 21 and the partition portion 25 of the rear cover portion 22 are rib-shaped extending in the X1 direction and extend parallel to each other.

Only the front cover part 21 and the rear cover part 22 are shown in the partial cross-sectional view of FIG. In the front cover portion 21, the width dimension W2 of the opening portion 26 and the width dimension W1 of the partition portion 23 are the same. Also in the rear cover portion 22, the width dimension W4 of the opening portion 26 and the width dimension W3 of the partition portion 25 are the same. The width dimension W2 of the opening 26 of the front cover portion 21 and the width dimension W4 of the opening portion 26 of the rear cover portion 22 are the same, and the width dimension W1 of the partition portion 23 of the front cover portion 21 and the partition of the rear cover portion 22 are the same. The width dimension W3 of the portion 25 is also the same.

As shown in FIGS. 1 and 2, the openings 24 formed in the front cover portion 21 are elongated in the X1 direction, and a plurality of openings 24 are arranged in rows in the X2 direction. The columns are partitioned by a transverse partition 27 extending in the X2 direction. The length dimension of the opening 24 in the X1 direction is longer than the width dimension of the transverse partition 27 in the X1 direction. Therefore, the opening ratio of the front cover portion 21 can be made as high as 50% or more, for example. A crossing partition is also provided in the rear cover part 22, and the length dimension of the opening 26 in the X1 direction is larger than the width dimension of the crossing partition in the X1 direction. The rear cover portion 22 can also have an aperture ratio of, for example, 50% or more. The front cover part 21 and the rear cover part 22 can secure a sufficient opening ratio and maintain a high strength.

As shown in FIGS. 3 and 4, the opening 24 and partition 23 of the front cover 21 and the opening 26 and partition 25 of the rear cover 22 are displaced in the X2 direction. The positional deviation between the openings and the partitions in the front cover part 21 and the rear cover part 22 is 1/2 of the arrangement pitch. are opposed to each other, and the partition portion 23 of the front cover portion 21 is opposed to the front of the opening portion 26 of the rear cover portion 22 . Therefore, the cover structure part 20 having the two cover parts 21 and 22 is excellent in dust resistance and water resistance.

As shown in FIGS. 1 and 4, the front cover portion 21 has a recess S1 formed in a circular region including the center line O. As shown in FIGS. An annular convex portion S2 centered on the center line O is formed outside the concave portion S1 in the radial direction from the center line O, an annular concave portion S3 is formed outside the concave portion S3, and further an annular convex portion is formed outside the concave portion S2. A portion S4 is formed. The rear cover portion 22 is also formed with an annular convex portion and an annular concave portion centered on the center line O so as to follow the front cover portion 21 .

As shown in FIGS. 3 and 4, the front cover portion 21 and the rear cover portion 22 are spaced apart in the front-rear direction (Y1-Y2 direction). A space C is formed between them. The interval dimension of the space C in the direction of sound generation is non-uniform and varies continuously so as to differ from place to place.

The cross-sectional view of FIG. 4 shows a plate thickness center line L1 connecting the center of the thickness dimension of the opening 24 of the front cover portion 21 and the partition portion 23 in the front-rear direction. A plate thickness center line L2 connecting the centers of thickness dimensions of the portion 26 and the partition portion 25 in the front-rear direction is shown. The plate thickness center line L1 is a curve extending in the X2 direction following the uneven shape of the front cover portion 21, and the plate thickness center line L2 is also a curve extending in the X2 direction.

As shown in FIG. 4, the distance between the plate thickness center line L1 and the plate thickness center line L2 is narrow at the concave portion S1 in the center of the front cover portion 21, and the width dimension H1 of the space portion C in the front-rear direction is at this portion. is narrowed. Similarly, the distance between the plate thickness center line L1 and the plate thickness center line L2 is narrow at the annular recess S3, and the width dimension H2 of the space C in the front-rear direction is narrow at this portion. In the portion of the annular projection S2 of the front cover portion 21, the width dimension H3 in the front-to-rear direction of the space C is wider than the width dimensions H1 and H2 of the recesses. The width dimension H4 in the front and rear of the recess is wider than the width dimensions H1 and H2 of the recess. That is, the change in the width dimension (rate of increase in width dimension) of the space C in the direction of sound generation changes continuously in a curvilinear manner following the changes in the plate thickness center lines L1 and L2.

Next, the sound generation operation of the speaker 1 will be described.
When a voice current is applied to the voice coil 18, the diaphragm 15 vibrates in the front-rear direction (Y1-Y2 direction) due to the electromagnetic force excited by the voice current and the magnetic field acting on the voice coil 18 in the magnetic circuit section 10. , the sound pressure is applied forward in the sounding direction (Y1 direction). The sound pressure is emitted forward of the case 2 through the opening 26 of the rear cover portion 22 and the opening 24 of the front cover portion 21 .

In the cover structure portion 20, the partition portion 25 of the rear cover portion 22 faces the rear of the opening 24 of the front cover portion 21, and the partition portion 23 of the front cover portion 21 faces the front of the opening 26 of the rear cover portion 22. Therefore, a space portion C is formed between the front cover portion 21 and the rear cover portion 22, which is separated by both cover portions. Sound pressure resonance (resonance) occurs in this space C, and when the resonance increases, peaks and dips appear in the sound formed by the vibration of the diaphragm 15, and noise tends to occur.

In the speaker of the embodiment, as shown in FIGS. 3 and 4, the width dimension in the front-rear direction of the space portion C is non-uniform, and the width dimension changes continuously from the center line O in the radial direction. there is Therefore, even if resonance occurs in the space C, the resonance frequency (resonance point) can be dispersed, an increase in peak dip can be suppressed, and noise can be reduced. In particular, in the cover structure part 20, since the rate of increase in the spacing of the space part C changes curvilinearly in the radial direction from the center line O, it is possible to smoothly disperse the resonant frequencies, and the occurrence of peak dips. can be effectively suppressed.

As shown in FIG. 1, the front cover portion 21 has a recess S1 formed at the position of the center line O, and radially outward from the center line O, an annular protrusion S2, an annular recess S3, and an annular protrusion. Portions S4 are formed alternately. Therefore, the appearance is good and the design is excellent.

As shown in FIGS. 3 and 4, the width dimension of the space C in the front-rear direction is narrow at the concave portions S1 and S3 and wide at the convex portions S2 and S4. Therefore, the rate of change in the uneven shape of the rear cover portion 22 can be made smaller than the rate of change in the uneven shape of the front cover portion 21, and the thickness dimension of the front cover portion 21 in the front-rear direction can be reduced. The thickness dimension of the cover portion 22 in the front-rear direction can be reduced. Therefore, as shown in FIG. 3, the rear cover portion 22 can be shaped to follow the shape of the diaphragm 15 and the edge member 16, and the distance between the rear cover portion 22 and the diaphragm 15 in the front-rear direction and the rear cover portion 22 and the edge member 16 can be made substantially uniform in the radial direction from the center line O. Thereby, it is possible to avoid forming extra space in the case 2 .

FIG. 5 shows a cover structure 20 used in a loudspeaker according to another embodiment of the invention. In FIG. 5, the plate thickness center line La of the front cover portion 21 and the plate thickness center line Lb of the rear cover portion 22 linearly change from the center line O in the radial direction. Therefore, the rate of increase in the longitudinal width dimension of the space C between the front cover portion 21 and the rear cover portion 22 linearly changes from the center line O in the radial direction. Also in this embodiment, since the width dimension of the space portion C is continuously changed, the frequencies that resonate in the space portion C can be dispersed, and an increase in peak-dip can be suppressed.

In the two embodiments described above, the width dimension of the space C in the front-rear direction changes continuously in a curved or straight line from the center line O radially outward. The width dimension of the portion C in the front-rear direction may vary stepwise depending on the location. Moreover, the front cover part 21 and the rear cover part 22 are not limited to the grille structure, and the respective openings may be square or round holes.

1 speaker 3 front case 10 magnetic circuit 15 diaphragm 17 bobbin 18 voice coil 21 front cover 22 rear cover 23 partition 24 opening 25 partition 26 opening C space H1, H2, H3, H4 space Width O Centerline S1, S3 Concave S2, S4 Convex

Claims (6)

A speaker provided with a magnetic circuit section including a magnet, a coil on which a magnetic field generated by the magnetic circuit section acts, and a diaphragm that vibrates together with the coil,
A plurality of cover portions are arranged in front of the diaphragm in the direction of sound generation, and each of the cover portions is provided with a plurality of openings and a plurality of partitions for partitioning the openings,
A space is formed between a front cover portion located farthest forward in the direction of sound generation and a rear cover portion located behind it,
1. A speaker according to claim 1, wherein said front cover portion has a convex portion and a concave portion, and the width dimension of said space portion in the direction of sound generation is non-uniform. 2. The loudspeaker according to claim 1 , wherein said convex portion and said concave portion are formed in an annular shape centered on a center line extending through said diaphragm and extending in a direction of sound generation. 3. The speaker according to claim 1 , wherein the width of said space in the direction of sound generation is narrow at said concave portion and wide at said convex portion. 4. The speaker according to any one of claims 1 to 3, wherein the rear cover portion has projections and recesses following the projections and recesses of the front cover portion. 5. The speaker according to any one of claims 1 to 4 , wherein the width dimension of said space changes continuously in a direction intersecting with the direction of sound generation. 6. The speaker according to claim 5 , wherein the width dimension of said space appearing in a cross section including a center line extending through said diaphragm and extending in a direction of sound generation curves in a direction intersecting said center line.

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