JPS6338630Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a horn speaker, and includes an equalizer having a structure including a separator that partitions a space on the exit side of radial slits so that each slit is acoustically independent. To provide a horn speaker which can exhibit frequency characteristics sufficiently extended to a high frequency range by eliminating sound interference in the treble range.

In general, a back-radiating horn speaker is equipped with an equalizer to match the impedance of the output of the diaphragm to the throat of the horn, while at the same time preventing phase interference, particularly in the high frequency range, to obtain a smooth sound pressure response. Figure 1 A and B are
In order to improve the above characteristics as an equalizer,
1 shows a part of a horn speaker equipped with an equalizer having a plurality of radially formed slits. The equalizer 1 has a structure in which a plurality of slits 3a to 3j are formed radially in a substantially conical main body 2, and is attached to a tapered portion 4a of a center pole 4. The sound waves radiated from the concave diaphragm 5 pass through each of the slits 3a to 3j, exit from the slits 3a to 3j, and are transmitted through the space 6 formed between the conical surface of the equalizer body 2 and the tapered portion 4a to reduce the sound inside the throat 4b. It is guided to path 7 and further radiated through the sound path inside the horn. Here, since the space 6 is an annular (umbrella-shaped) space without circumferential partitions, some of the sound waves emitted from different slits mix within the space 6, causing phase interference. It ends up. For example, the sound waves radiated from different points A and B on the diaphragm 5 are transmitted through the corresponding slits 3a and 3 as shown by thick broken lines.
The sound wave passes through the slit 3f, exits into the space 6, and heads directly to the sound path 7, but a part of the sound wave that comes out from the slit 3f enters the space 6.
go around in the circumferential direction along the slit 3a at point C.
Together with the sound waves emitted by the sound waves, they head towards sound path 7. Therefore, the travel distance of a sound wave radiated from point A and directly reaching the sound path and the travel distance of some sound waves radiating from point B and reaching the sound path via points D and C are point D.
There is a difference in arc length from point C to point C, and interference occurs in a frequency band higher than the frequency at which this distance difference is λ/2 (λ: wavelength), and the sound pressure is attenuated. For example, when the arc length is 2.5 cm, interference starts to occur at 6800 Hz. For this reason, the sound pressure frequency characteristics of the above-mentioned horn speaker have a lower level in the high range, as shown by the broken graph line in Figure 5, and it is said that a sufficiently satisfactory sound pressure frequency characteristic cannot be obtained. There were flaws.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.

FIG. 2 shows a driver unit of an embodiment of the horn speaker according to the present invention. This horn speaker driver unit 10 includes a magnetic circuit section 11
A diaphragm 12 and an equalizer 13, which is the main part of the present invention, are incorporated inside. In the magnetic circuit section 11, a ferrite magnet 14 is sandwiched between a top plate 15 and a base plate 16c which is integrated with the center pole 16, and is screwed to the base plate 16c. A gap 17 is formed. A voice coil 18 is inserted into the magnetic gap 17, and the voice coil 18 and the diaphragm 12 are directly connected. The center pole 16 also has a tapered portion 16a that is tapered at the top in the direction of sound wave propagation, and a throat portion 16b that is continuous with the tapered portion 16a and has a tapered shape that widens at the opposite end. The space within the throat portion 16b and the space within the front cover 19 continuously form a sound path 20. Further, a back cover 21 that covers the diaphragm 12 is attached to the back side of the magnetic circuit section 11, and a sound absorbing material 22 is provided inside this back cover 21.

The equalizer 13 is built into a tapered portion 16a within the center pole 16. As shown in FIGS. 3A to 3D, this equalizer 13 has a conical equalizer body 30 with radial slits 3.
1a to 31j and the partition plate portion 3 which constitutes the main part of the present invention
2a to 32j are provided.

3B and 3D are cross sections taken along line B-B and line D-D in FIG. 3C, respectively, and FIG. 4 is a cross section taken along line - in FIG. 3B. The top surface α ₁ of the equalizer body 30 is the tapered portion 1 of the center pole 16
6a is set to be larger than the taper angle α ₂ of
6a is formed with an umbrella-shaped space 33 that becomes wider toward the center of the sound path.

Here, the ten slits 31a to 31j and the partition plate portions 32a to 32j will be explained. First, the slits 31a to 31j have the same width (1 mm) and are arranged at equal angular intervals. Also, the slit 31a~
31j is a slit 31a, 3 with a cutting depth of _d1 .
The slits 1c, 31e, 31g, 31i and the slits 31b, 31d, 31f, 31h, 31j of small size _d2 are arranged alternately in the circumferential direction. Further, in this embodiment, since the number of slits is an even number, the slits with a large cutting depth and the slits with a small cutting depth face each other in the radial direction as well. By arranging the slits having different cutting depths alternately in the circumferential direction, the following effects are achieved.

Concentration of the slits near the center of the equalizer body can be avoided, and many slits can be formed without particularly impairing the mechanical strength of the equalizer body 30. This makes it possible to reduce the distance S between adjacent slits in the circumferential direction, and to extend the upper limit frequency at which interference begins.

Furthermore, the interval T between the slits in the approximately radial direction at the center of the dome-shaped surface 30a facing the diaphragm 12 of the equalizer body can be made small, which can similarly contribute to raising the high-frequency limit frequency.

Further, the partition plate portions 32a to 32j are formed in the shape of wings so as to protrude outward from the conical surface 30b of the equalizer main body 30 at the center of circumferentially adjacent slits. Each of the partition plate portions 32a to 32j has a substantially triangular shape and is formed near the top of the equalizer main body 30. The equalizer 13 is assembled with the top surfaces of the partition plate parts 32a to 32j in contact with the inner surface of the center pole tapered part 16a. As a result, especially as shown in FIG. 4, the umbrella-shaped space 33 is partitioned into spaces communicating with the respective slits 31a-31j by the partition plate portions 32a-32j. Therefore, channels 34a-34j that are acoustically independent from each other are formed on the exit side of each slit 31a-31j.

Therefore, the sound waves radiated from the diaphragm 12 pass through each of the slits 31a to 31j of the equalizer 13, exit into the corresponding channels 34a to 34j, and pass through each channel 34a to 34j separately to the center of the sound path. They are guided together and then emitted from a horn (not shown) through a sound path 20. That is, all of the sound waves emitted from each slit 31a to 31j are transmitted to the corresponding channel 3.
It spreads through 4a to 34j and is guided to the sound path. Therefore, phase interference between sounds radiated from adjacent slits within the umbrella-shaped space 33 does not occur, and the sound pressure frequency characteristics of the horn speaker using the driver unit 10 described above are shown by the graph line in FIG. As a result, the sound pressure is maintained sufficiently up to the high frequency range, and the horn speaker has an extended reproduction band in the high frequency range.

Further, due to its shape, the above-mentioned equalizer 13 has an equalizer main body 30 and partition plate parts 32a to 32.
j can be integrally molded with resin such as glass-filled polycarbonate. By integrally molding the partition plate portions 32a to 32j with the equalizer main body 30 in this manner, the equalizer 13 is inexpensive and stable in quality. Further, this equalizer 13 has an outer peripheral flange portion 35 in contact with one end surface of the center pole 16, and a partition plate portion 3
2a to 32j are adhesively fixed in contact with the inner surface of the center pole tapered portion 16a, and there is no need for curved surface processing after assembly, making the assembly work easy.

As described above, the horn speaker according to the present invention is a horn speaker including an equalizer having a plurality of slits arranged radially in the main body, in which the equalizer is extended outward from the main body between circumferentially adjacent slits. Since the structure has a partition plate section that makes the space on the slit exit side acoustically independent for each slit, phase interference between sound waves radiated from different slits within the slit exit space is ensured. As a result, the reproduction band can be sufficiently extended to the high frequency range, and since the partition plate part is integrated with the equalizer main body, it has features such as low cost and easy assembly work.

[Brief explanation of the drawing]

Figures 1A and 1B show one example of a conventional horn speaker, respectively.
A cross-sectional view and a right side view showing an enlarged equalizer portion of the example, FIG. 2 is a cross-sectional view of a driver unit portion of an example of the horn speaker according to the present invention, and FIGS. FIG. 4 is a cross-sectional view taken along the center line of FIG. 3B, and FIG. It is a figure shown in comparison with it. 10...Horn speaker driver unit,
11... Magnetic circuit section, 12... Vibration plate, 13...
Equalizer, 14...Ferrite magnet, 1
5... Top plate, 16... Center pole, 17... Magnetic gear, 18... Voice coil, 20... Sound path, 30... Equalizer body, 3
1a-31j...slit, 32a-32j...
Partition plate portion, 33...Umbrella-shaped space, 34a to 34
j...Channel, 35...Tsubabe.

Claims (1)

[Scope of utility model registration request] In a horn speaker equipped with an equalizer having a plurality of slits arranged radially in a main body, the equalizer is extended outward from the main body between circumferentially adjacent slits, and the space on the slit exit side is divided into two parts. A horn speaker having a structure having partition plate sections that are acoustically independent from each other.