JP7708789B2 - Sound emitting member for speaker and speaker device - Google Patents

Description

The present disclosure relates to a speaker sound-emitting member and a speaker device.

Cone-type speakers have a center cap in the center of the cone-shaped diaphragm. The center cap is a dome-shaped sound-emitting member that vibrates with the cone, and tends to affect mainly mid-range and higher sounds. In dome-type speakers such as tweeters, the dome-shaped sound-emitting member functions as the main diaphragm.

For example, Patent Document 1 discloses a cone-type speaker with a bullet-shaped center cap in the center of the cone-shaped diaphragm. In the speaker of Patent Document 1, the bullet-shaped center cap has a high mechanical strength in the direction of sound pressure emission, so the high-frequency resonance frequency shifts to a higher frequency range and a sharp peak dip occurs. In contrast, the bullet-shaped center cap of Patent Document 1 has a smaller radius of curvature in the center than in other parts, and a highly flexible part is provided in this other part, thereby suppressing the peak dip in the high frequency range.

Publication number 1-41273

However, due to its structure, the bullet-shaped center cap in Patent Document 1 is long in the direction of sound pressure emission, which means that the overall height of the center cap is high, which hinders speaker miniaturization. For example, speakers used in portable speakers require center caps to be thin, and there is also a demand for further improvements in high-frequency characteristics.

This disclosure has been made to solve these problems, and its purpose is to provide a speaker sound-emitting component and speaker device that can achieve both improved high-frequency characteristics and a slim design.

In order to achieve the above-mentioned objective, the sound-emitting member of the speaker disclosed herein includes a dome portion having a shape of a rotating body rotated within the range from the intersection of the quarter ellipse arc with the rotation axis to the intersection of the quarter ellipse arc with the rotation axis, the dome portion having a shape of a rotating body rotated within the range from the intersection of the quarter ellipse arc with the rotation axis to the intersection of the quarter ellipse with the major axis.

The sound-emitting member of the above-mentioned speaker may have a cylindrical portion connected to the opening edge of the dome portion and having the rotation axis as its central axis.

The sound-emitting member of the above-mentioned speaker may have a flange portion extending radially from the tip edge of the cylindrical portion relative to the rotation axis.

In addition, in order to achieve the above-mentioned object, the speaker device of the present disclosure comprises a sound-emitting member of the above-mentioned speaker and a cylindrical voice coil bobbin that fits into an opening of the sound-emitting member.

The above-mentioned speaker device may further include a cone-shaped diaphragm connected to the outer peripheral surface of the voice coil bobbin.

The speaker sound-emitting member and speaker device disclosed herein, which use the above-mentioned means, can achieve both improved high-frequency characteristics and a slim design.

1 is a perspective view of a speaker device including a sound emitting member according to a first embodiment of the present disclosure; 1 is a side cross-sectional view of a speaker device including a sound radiating member according to a first embodiment of the present disclosure. FIG. 2 is a structural explanatory diagram consisting of a plan view and a side sectional view of the center cap. 1A is a graph showing frequency characteristics of the speaker device according to the first embodiment and a speaker device of a first comparative example, and FIG. 1B is a partial side cross-sectional view of a center cap of the first comparative example. 1A is a graph showing frequency characteristics of the speaker device according to the first embodiment and a speaker device of a second comparative example, and FIG. 1B is a partial side cross-sectional view of a center cap of the second comparative example. 11 is a perspective view of a speaker device including a sound radiating member according to a second embodiment of the present disclosure. FIG. 11 is a side cross-sectional view of a speaker device including a sound radiating member according to a second embodiment of the present disclosure. FIG.

Below, an embodiment of the present disclosure is described based on the drawings.

First Embodiment
Fig. 1 is a perspective view of a speaker device 1 according to a first embodiment. Fig. 2 is a side cross-sectional view of the speaker device 1. The configuration of the speaker device 1 according to the first embodiment will be described below with reference to these drawings.

The speaker device 1 of this embodiment is a cone-type speaker with a center cap, and has a vibration unit 10 and a magnetic circuit unit 20. In the following description of this embodiment, the speaker device 1 will be described with the vibration unit 10 side on the central axis O1 as the front side, and the magnetic circuit unit 20 side as the rear side. The speaker device 1 radiates sound from the vibration unit 10 toward the front side.

The vibration section 10 comprises a center cap 11, a cone-shaped diaphragm 12, and an edge section 13. The center cap 11, which is a dome-shaped sound-emitting member, is disposed in the center of the vibration section 10, and the cone-shaped diaphragm 12 extends radially from the center. An edge section 13 is formed on the outer periphery of the cone-shaped diaphragm 12. The outer periphery of the edge section 13 is connected to a frame 14. The frame 14 has a cross-sectional concave shape whose diameter gradually decreases toward the rear side, and the rear side end of the frame 14 is connected to a yoke 21 of the magnetic circuit section 20.

The material of each part of the vibrating part 10 is not particularly limited. For example, the center cap 11 and the cone-shaped diaphragm 12 can be made of various materials such as paper, polymer, metal, or a combination of these materials and ceramics. The edge part 13 can be made of a relatively highly elastic polymer material such as rubber or resin. In addition, natural fiber or synthetic fiber materials may also be used as the material of each part of the vibrating part 10. Furthermore, the base material of each part of the vibrating part 10 may be coated with a rubber coat or the like.

The frame 14 can be made of a metal material. The magnetic circuit section 20 includes a yoke 21, a first magnet 22, a main plate 23, a second magnet 24, and a top plate 25. Inside the bottomed cylindrical yoke 21, the first magnet 22, the main plate 23, the second magnet 24, and the top plate 25 are stacked along the central axis O1.

Specifically, the yoke 21 has a disk-shaped bottom 21b, a cylindrical portion 21a standing from the periphery of the bottom 21b, and a cylindrical protrusion 21c protruding from the center of the bottom 21b to the front side. A first magnet 22 having a cylindrical shape and the same diameter as the protrusion 21c is laminated on the top surface (front surface) of the protrusion 21c. A cylindrical main plate 23 having a slightly larger diameter than the first magnet 22 is laminated on the first magnet 22. A cylindrical second magnet 24 having the same diameter as the first magnet 22 is laminated on the main plate 23, and a cylindrical top plate 25 having the same diameter is laminated on the second magnet 24. The thickness of each of these components in the direction of the central axis O1 becomes thinner in the order of the main plate 23, the first magnet 22, the second magnet 24, and the top plate 25. The diameters and thicknesses of the protrusions of the yoke, the first magnet, the main plate, the second magnet, and the top plate are merely examples, and the shapes and dimensions are not limited to these.

Between the outer circumferential surface of the main plate 23 and the inner circumferential surface of the cylindrical portion 21a of the yoke 21, a cylindrical voice coil bobbin 26 is disposed, which extends toward the front side with the central axis O1 as its axis. A voice coil 27 is wound around the outer circumferential surface of the voice coil bobbin 26 in a position facing the outer circumferential surface of the main plate 23. The voice coil bobbin 26 is supported by the frame 14 via an elastic damper 28, and can vibrate in the direction of the central axis O1. Note that a cone-type speaker without a damper 28 may also be used.

The magnetic circuit section 20 is a so-called repulsive magnetic circuit in which a first magnet 22 and a second magnet 24, which are permanent magnets, are arranged with the same poles facing each other, and a voice coil 27 is arranged in a repulsive magnetic field generated on the outer periphery of a main plate 23 made of a magnetic material arranged between the two magnets 22 and 24. Although not shown, the voice coil 27 is connected to a signal transmission circuit, and the voice coil bobbin 26 vibrates together with the voice coil 27 upon receiving a signal from the signal transmission circuit, and the vibration is transmitted to the center cap 11 and the cone-shaped diaphragm 12, which vibrate and radiate sound.

The cone-shaped diaphragm 12 of the vibrating part 10 is adhered to the outer peripheral surface of the front side of the voice coil bobbin 26 with an adhesive, and the center cap 11 is fitted (externally fitted) into the opening on the front side of the voice coil bobbin 26.

Figure 3 shows a structural diagram consisting of a plan view and a side cross-sectional view of the center cap 11. The center cap 11 will be described in more detail below based on this figure.

In this embodiment, the center cap 11 is composed of a dome portion 11a, a cylindrical portion 11b, and a flange portion 11c.

As shown in FIG. 3, the dome portion 11a has a shape of a part of an ellipse. Specifically, the dome portion 11a has a shape of a part of an ellipse Ea (hereinafter referred to as a quarter ellipse Ea) of an ellipse E shown by a two-dot chain line in FIG. 3, cut by a major axis Al (semi-major axis) and a minor axis As (semi-minor axis) shown by a solid line, and rotated around a rotation axis Ar parallel to the minor axis As. The rotation axis Ar is a straight line parallel to the minor axis As that passes through a position moved (offset) from the intersection (origin) of the minor axis As and the major axis Al toward the tip side of the major axis (in the direction of shortening the major axis). The part of the quarter ellipse Ea between the intersection P1 with the rotation axis Ar and the intersection P2 with the major axis Al is rotated around the rotation axis Ar to form the shape of a part of an ellipse of the dome portion 11a, and the shaded portion in FIG. 3 is the internal space of the dome portion 11a.

That is, the dome portion 11a has a shape of a rotating body rotated in the range from the intersection point P1 with the rotation axis Ar to the intersection point P2 with the major axis Al on the quarter ellipse arc Ea, with the rotation axis Ar being a straight line perpendicular to the major axis Al on the quarter ellipse arc Ea and different from the minor axis As. The dome portion 11a configured in this way is arranged so that the rotation axis Ar coincides with the central axis O1 when attached to the speaker device 1. The apex of the dome portion 11a is the intersection point P1 between the quarter ellipse arc Ea and the rotation axis Ar, and the apex has a slightly pointed shape. Note that the rotation axis Ar of the dome portion 11a is preferably located closer to the minor axis As than the center on the major axis Al of the quarter ellipse arc Ea so that the height H from the opening to the apex on the central axis O1, that is, the length of the rotation axis Ar, is shorter than the opening radius R.

The cylindrical portion 11b is connected to the opening edge of the dome portion 11a and is a cylindrical portion with the rotation axis Ar as its central axis. The opening edge of the dome portion 11a is the intersection P2 with the major axis Al on the quarter ellipse arc Ea, and the cylindrical portion 11b extending from the opening edge along the rotation axis Ar extends in the normal direction of the opening edge of the dome portion 11a. Therefore, the cylindrical portion 11b is smoothly connected to the opening edge of the dome portion 11a without creating an inflection point.

The flange 11c is an expanded diameter portion that expands radially from the tip edge of the cylindrical portion 11b relative to the rotation axis Ar. More specifically, the flange 11c extends from the tip edge of the cylindrical portion 11b toward the rear side and smoothly curves radially outward. The outer peripheral edge of the flange may be curved further upward.

The center cap 11 configured in this manner is placed over the opening of the voice coil bobbin 26, and the inner peripheral surface of the cylindrical portion 11b and the outer peripheral surface of the opening edge of the voice coil bobbin 26 are bonded. In other words, the bonding surface between the center cap 11 and the voice coil bobbin 26 is parallel to the vibration direction. Furthermore, as shown in FIG. 2, the bonding portion between the center cap 11 and the voice coil bobbin 26 is separated from the bonding portion between the cone-shaped diaphragm 12 and the voice coil bobbin 26, and the center cap 11 and the cone-shaped diaphragm 12 are not in direct contact. This has the advantage that the vibrations of the center cap 11 and the cone-shaped diaphragm 12 do not interfere with each other because they are not in direct contact with each other. However, this configuration is not limited to this, and the center cap and the cone-shaped diaphragm may be in contact with each other.

Figure 4 shows (a) a graph showing the frequency characteristics of the speaker device 1 according to the first embodiment and the speaker device of the first comparative example, and (b) a partial cross-sectional side view of the center cap of the first comparative example. Figure 5 shows (a) a graph showing the frequency characteristics based on a simulation result of the speaker device 1 according to the first embodiment and the speaker device of the second comparative example, and (b) a partial cross-sectional side view of the center cap of the second comparative example. Below, the action and effect of the speaker device 1 equipped with the sound emitting member of the first embodiment will be explained based on these figures.

Figure 4 (a) shows frequency (in Hz) on the horizontal axis and speaker output sound pressure level (in dB) on the vertical axis, with the characteristics of the speaker device 1 of the first embodiment shown by a solid line and the characteristics of the speaker device of the first comparative example shown by a dotted line.

The speaker device 1 of this embodiment and the speaker device of the first comparative example are different only in the center cap. The center cap 101 of the first comparative example is dome-shaped as shown in FIG. 4(b). In the side cross section of the center cap 101 of the first comparative example, the top surface 101a is an arc shape with a certain curvature, and a conical surface 101b is formed that expands radially outward as it approaches the opening side (back side) from the periphery of the top surface 101a, and a flange portion 101c is folded back from the opening end of the conical surface 101b to the front side. In the center cap 101 of the first comparative example, the flange portion 101c is attached by being glued to the cone-shaped diaphragm. Note that the center cap 11 of the speaker device 1 of the first embodiment having the characteristics shown in FIG. 4(a) is made of aluminum, and the center cap 101 of the first comparative example is made of a polymer (resin) film.

In the speaker device of the first comparative example shown by the dotted line in Fig. 4(a), a peak occurs near 10 kHz on the high-frequency side, and a dip occurs near 12.5 kHz, resulting in non-uniform high-frequency characteristics. In contrast, in the speaker device 1 of the first embodiment shown by the solid line in Fig. 4(a), the peak near 10 kHz in the comparative example disappears, and the dip near 12.5 kHz is also suppressed, resulting in uniform high-frequency characteristics.

Figure 5 (a) shows frequency (in Hz) on the horizontal axis and speaker output sound pressure level (in dB) on the vertical axis, with the characteristics of the speaker device 1 of the first embodiment shown by a solid line and the characteristics of the speaker device of the second comparative example shown by a dotted line.

The speaker device 1 of this embodiment and the speaker device of the second comparative example differ only in the center cap. The center cap 201 of the second comparative example is dome-shaped as shown in FIG. 5(b). In the side cross section of the center cap 201 of the second comparative example, the entire dome portion 201a is an arc shape with a constant curvature, and the opening end of the dome portion 201a has a flange portion 201b that is folded back to the front side. In the center cap 201 of the second comparative example, the flange portion 201b is attached by being glued to the cone-shaped diaphragm. The center cap 11 of the speaker device 1 of the first embodiment having the characteristics shown in FIG. 5(a) is made of aluminum, and the center cap 201 of the second comparative example is also made of aluminum.

In the speaker device of the second comparative example shown by the dotted line in Fig. 5(a), a peak occurs near 10 kHz on the high-frequency side, and a dip occurs near 15 kHz, resulting in non-uniform high-frequency characteristics. In contrast, in the speaker device 1 of the first embodiment shown by the solid line in Fig. 5(a), the peak near 10 kHz in the second comparative example disappears, and the dip near 15 kHz is suppressed while moving to the vicinity of 12.5 kHz, resulting in uniform high-frequency characteristics.

In this manner, in the speaker device 1 of this embodiment, the dome portion 11a of the center cap 11 has a partially elliptical arc shape, and while the length in the direction of the central axis O1 is shortened, the apex is slightly pointed, thereby improving the shape rigidity.

In addition, the center caps 101 and 201 of the first and second comparative examples are attached to a diaphragm, so that vibrations are transmitted from the voice coil to the center caps 101 and 201 via the diaphragm. Furthermore, the center cap 101 of the first comparative example has an inflection point in the dome portion. In contrast, the center cap 11 of this embodiment has a shape in which there is no inflection point from the apex to the opening edge in the dome portion 11a, and furthermore, the cylindrical portion 11b of the opening edge is connected without an inflection point. In addition, since the cylindrical portion 11b is formed to extend parallel to the vibration direction of the voice coil bobbin 26, the transmission efficiency from the voice coil bobbin 26 can be improved more than the center caps 101 and 201 of the comparative examples while increasing the rigidity of the center cap 11. Therefore, split resonance of the center cap 11 can be prevented, and the high-frequency characteristics can be improved as shown in Figures 4(a) and 5(a).

Furthermore, the center cap 11 has a flange 11c formed at the tip edge of the cylindrical portion 11b, which is smoothly curved radially outward, so that the flange 11c functions as a guide when attaching the center cap 11 to the voice coil bobbin 26. This allows the center cap 11 to be easily fitted to the voice coil bobbin 26, improving the ease of attachment of the center cap 11.

In this way, the center cap 11 of the first embodiment is able to achieve both improved high-frequency characteristics and a slim design, and the speaker device 1 equipped with this center cap 11 is also able to achieve both improved high-frequency characteristics and a slim design.

Second Embodiment
The speaker device 1 of the first embodiment is a cone-type speaker, but the speaker to which the sound emitting member of the present invention can be applied is not limited to this, and the sound emitting member of the present invention can also be applied to a dome-type speaker such as a tweeter.

Figure 6 is a perspective view of the speaker device 2 according to the second embodiment, and Figure 7 is a side cross-sectional view of the speaker device 2. The speaker device 2 according to the second embodiment will be described below with reference to these figures.

The speaker device 2 of the second embodiment is a dome-shaped speaker, and has a vibration unit 30 and a magnetic circuit unit 40. In the following description of the speaker device 2, the vibration unit 30 side on the central axis O2 is referred to as the front side, and the magnetic circuit unit 40 side is referred to as the rear side. In the speaker device 2, sound is radiated from the vibration unit 30 toward the front side.

The vibration section 30 comprises a dome-shaped vibration plate 31 and an edge section 32, and the edge section 32 is connected to the periphery of the dome-shaped vibration plate 31. The outer peripheral edge of the edge section 32 is clamped and fixed by a first frame 53 and a second frame 54.

The dome-shaped diaphragm 31 is a sound-emitting member similar to the center cap 11 of the first embodiment, and is composed of a dome portion 31a, a cylindrical portion 31b, and a flange portion 31c. The configuration of each of these portions is similar to that of the first embodiment, and a description thereof will be omitted. However, in the dome-shaped diaphragm 31 of the second embodiment, an edge portion 32 is bonded from the outer periphery of the cylindrical portion 31b to the flange portion 31c.

The magnetic circuit section 40 has a magnet 42 and a plate 43 stacked inside a cylindrical yoke 41 with a bottom, and a cylindrical voice coil bobbin 45 with a voice coil 44 wound around it is disposed between the plate 43 and the yoke 41.

The voice coil bobbin 45 extends in the direction of the central axis O2, and the outer peripheral surface on the front side is fitted and bonded to the inner peripheral surface of the cylindrical portion 31b of the dome-shaped diaphragm 31. Although not shown, the voice coil 44 is connected to a signal transmission circuit, and upon receiving a signal from the signal transmission circuit, the voice coil bobbin 45 vibrates together with the voice coil 44, and the vibration is transmitted to the dome-shaped diaphragm 31, emitting sound.

In the speaker device 2 of the second embodiment configured in this manner, the dome portion 31a of the dome-shaped diaphragm 31 has a partially elliptical arc shape, so that the length in the direction of the central axis O2 can be shortened while improving the shape rigidity. In addition, the same effects as those of the first embodiment can be achieved, and the dome-shaped diaphragm 31 of the second embodiment can achieve both improved high-frequency characteristics and a slim design, and the speaker device 2 equipped with the dome-shaped diaphragm 31 can also achieve both improved high-frequency characteristics and a slim design.

This concludes the explanation of the first and second embodiments of the present disclosure, but the scope of the present disclosure is not limited to these embodiments.

For example, the configuration of the magnetic circuit section is not limited to the above embodiment and may be other configurations of the magnetic circuit section.

1, 2 Speaker device 10, 30 Vibration part 11 Center cap (sound emitting member)
11a, 31a Dome portion 11b, 31b Cylindrical portion 11c, 31c Flange portion 12 Cone-shaped diaphragm 13, 32 Edge portion 14 Frame 20, 40 Magnetic circuit portion 21, 41 Yoke 22 First magnet 23 Main plate 24 Second magnet 25 Top plate 26, 45 Voice coil bobbin 27, 44 Voice coil 28 Damper 31 Dome-shaped diaphragm (sound emitting member)
53 First frame 54 Second frame 42 Magnet 43 Plate

Claims (5)

A sound-emitting component of a speaker that includes a dome portion having a shape of a rotating body rotated within the range from the intersection of the quarter ellipse with the rotation axis to the intersection of the quarter ellipse with the rotation axis, the dome portion having a rotation axis that is perpendicular to the major axis and different from the minor axis on the quarter ellipse. The sound-emitting member of the speaker according to claim 1, which has a cylindrical portion connected to the opening edge of the dome portion and having the rotation axis as its central axis. A sound-emitting member for a speaker as described in claim 2, having a flange portion extending radially from the tip edge of the cylindrical portion relative to the rotation axis. A sound emitting member of a speaker according to any one of claims 1 to 3;
a cylindrical voice coil bobbin that fits into the opening of the sound emitting member;
A speaker device comprising: The speaker device according to claim 4 , further comprising a cone-shaped diaphragm connected to an outer circumferential surface of the voice coil bobbin.