JP2000152363A - Dynamic speaker unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic speaker unit easy in wiring to a voice coil and capable of obtaining satisfactory frequency characteristics wide in reproduction frequency band. SOLUTION: A 2nd diaphragm 12 is provided to outer circumference of a cone diaphragm 1 that is driven through connection to a voice coil 4. The diaphragm 12 is formed conical made of an electrically insulated material and a large diameter part 12a is in contact with an outer circumferential face of the cone diaphragm 1 and a small diameter part 12b is parted from the cone diaphragm 1 and connects to the outre circumference of the voice coil 4. Thus, the strength of the cone diaphragm 1 is increased to increase a maximum input, and distortion at a low frequency of the cone diaphragm 1, split vibration at a high frequency and resonance can be suppressed, the reproduction frequency band is extended and satisfactory frequency characteristics can be obtained. Furthermore, a lead wire 13 connects to the diaphragm 12 and power is supplied to the voice coil 4 through the lead wire 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodynamic loudspeaker unit having a wide reproduction frequency band and obtaining good frequency characteristics.

[0002]

2. Description of the Related Art Conventionally, a speaker unit of an electrodynamic type, an electrostatic type, a piezoelectric type, an electromagnetic type or the like is known. Of these, electrodynamic speakers (dynamic speakers)
Are classified into moving coil type, ribbon type, Bratthara type, Heile type, etc. according to the structure of the diaphragm and its vibration source.The basic principle is that the diaphragm is driven by electromagnetic force. Since high conversion efficiency can be obtained with a simple structure, it has become the mainstream of loudspeakers. Among them, the moving coil type occupies most of the electrodynamic type speaker,
This includes cone speakers and dome speakers.

Among them, the cone type speaker uses a conical diaphragm (cone diaphragm), as shown in FIG. 6, and generates a voice for generating an electromagnetic force for driving the cone diaphragm C. The coil Vc, the magnetic circuit Mc, the damper D for keeping the voice coil Vc at a fixed position with respect to the gap Gp of the magnetic circuit Mc, the edge E supporting the periphery of the cone diaphragm C connected to the tip of the voice coil Vc. , And a frame F connecting these components.

According to this type of speaker unit, a voice current is caused to flow through the lead wire L to the boil coil Vc placed in the gap of the magnetic circuit, so that the voice coil reciprocates in a direction perpendicular to the line of magnetic force and is directly connected. Can be driven.

[0005] Here, the voice coil is formed by winding a copper wire or the like on a tubular bobbin made of, for example, paper, aluminum, a polymer material, or a composite material thereof, and is integrated therewith. The cone diaphragm is formed of paper, metal such as aluminum, ceramics, or plastic such as polypropylene, which is made of wood pulp and various fibers such as carbon fibers.

In particular, the cone diaphragm is made of paper to form concentric folds called corrugation, or made of plastic and mixed with carbon in order to prevent split vibration in which the whole is unevenly moved. The rigidity is increased by using metal as described above. Among them, the plastic cone diaphragm can obtain relatively high rigidity by mixing carbon as described above, and can be easily formed. The spread is remarkable because of its excellent appearance.

[0007]

However, of the electrical input applied to the loudspeaker, most of the remaining electrical energy converted into acoustic energy is converted into heat by the voice coil, so that an excessive electrical input is applied. In addition to burning out the voice coil, the plastic cone diaphragm is made of thermoplastic resin such as polypropylene or polyester, so if you connect the lead wire to the boil coil with solder, the connection will be Thermal deformation will occur.

In addition, although a suitable vibration characteristic can be easily obtained with a conductive diaphragm made of plastic or carbon or metal on which metal is deposited on the surface, a short circuit occurs if a lead wire is directly connected to the portion. However, in this case, insulating paper must be stuck on the cone diaphragm, the lead wire must not be laid on the cone diaphragm, and a certain area must be secured between the damper and the lead wire, or drawn along the damper. There was a disadvantage that it did not become.

Further, since the cone diaphragm is driven alone at only one portion connected to the voice coil, the reproduction frequency band is narrow, such as distortion in the low frequency range and split vibration and resonance in the high frequency range. As a result, there is a disadvantage that the frequency characteristic is disturbed and a sound quality habit called coloration occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrodynamic loudspeaker unit which is easy to wire to a boil coil and has a wide reproduction frequency band and good frequency characteristics. Is to provide.

[0011]

In order to achieve the above object, the present invention provides an electrodynamic speaker unit having a voice coil and a cone diaphragm connected to the voice coil. It is another object of the present invention to provide an electrodynamic loudspeaker unit characterized in that a second diaphragm for connecting a voice coil and a portion on the peripheral surface of the cone diaphragm is provided above.

In particular, in the invention according to claim 2, the second diaphragm connecting the cone diaphragm and the voice coil has a conical shape made of an electrically insulating material, and the large-diameter portion has the outer periphery of the cone diaphragm. The present invention provides an electrodynamic speaker unit that is connected to a surface and has a small-diameter portion connected to a voice coil.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a preferred example of an electric speaker unit according to the present invention.
FIG. 2 is a partial cross-sectional view showing a main part thereof partially broken away. In FIG. 1, reference numeral 1 denotes a cone-shaped (tapered) plastic cone diaphragm formed by injection molding or blow molding using a thermoplastic resin such as polypropylene as a main material, and 2 drives the cone diaphragm 1. The vibration source 2 includes a magnetic circuit 3 for generating an electromagnetic force for driving the cone diaphragm 1 and a voice coil 4.

The magnetic circuit 3 comprises a pair of plates 5 and 6 made of, for example, a magnetic material connected via a ring-shaped magnet 7 and a pole piece 8 disposed at the center thereof. According to this, the magnetic flux of the magnet 7 can be concentrated in the gap 9 by the pair of plates 5, 6 and the pole piece 8, and a magnetic field can be generated in a direction perpendicular to the voice coil 4 placed in the gap.

On the other hand, the voice coil 4 is formed by, for example, winding a copper wire or the like coated with an insulating film around an aluminum bobbin 10. According to the voice coil 4, the gap in the magnetic circuit 3 is increased as described above. 9, the cone diaphragm 1 is connected to the tip side. In particular, the cone diaphragm 1 is connected to the bobbin 10 with an adhesive or the like at one end centered on the voice coil 4. A spherical cap 11 is attached to the inner peripheral surface of the cone diaphragm 1 so as to cover the end of the voice coil at a portion where the voice coil 4 penetrates. Note that the tip of the voice coil 4 is connected to the back surface of the cap 11 by an adhesive or the like, so that the resonance of the cap 11 is suppressed, and the sound quality in a high frequency range can be improved.

Here, reference numeral 12 denotes a second diaphragm provided separately from the cone diaphragm 1, and as shown in FIG. 2, the diaphragm 12 has an outer periphery of the cone diaphragm 1 as a main cone. And a portion on the peripheral surface of the cone diaphragm 1 and the voice coil 4.

In particular, the diaphragm 12 as a sub-cone (drive cone) is formed by forming an electrically insulating material containing no conductive material into a conical (tapered) shape. The opening edge on the large-diameter portion 12a side is connected to an intermediate portion of the outer peripheral surface of the cone diaphragm 1 using an adhesive or the like, and the opening edge on the small-diameter portion 12b side is formed by cone vibration. The voice coil 4 is connected to the outer periphery of the voice coil 4 at a distance from the plate 1. The connection between the cone diaphragm 1 and the diaphragm 12 on the bobbin 10 of the voice coil 4 is separated from each other by about several mm to several cm. A lead wire 13 is connected to the peripheral surface of the diaphragm 12, and a driving current is supplied to the voice coil 4 through the lead wire 13.

Therefore, according to the diaphragm 12, the cone diaphragm 1 can be protected from the heat generation of the voice coil 4, and the wiring to the voice coil 4 can be easily performed regardless of the material of the cone diaphragm 1. Further, the distortion of the cone diaphragm 1 in the low frequency range, the divided vibration in the high frequency range, and the resonance can be suppressed.

In FIG. 1, reference numeral 14 denotes a frame, 1
Reference numeral 5 denotes a damper for keeping the boiling coil 4 at a fixed position with respect to the gap 9 of the magnetic circuit 3, and 16 denotes a cone diaphragm 1.
An edge 17 formed at the opening edge of the distal end of the frame to prevent the lateral vibration of the frame 16 is a gasket for fixing the edge 16 to the frame 14.

Here, the frequency characteristics of the speaker unit of the present invention configured as described above and the conventional speaker unit shown in FIG. 6 will be compared.

[0021]

[Table 1]

[0022]

[Table 2]

Table 1 is based on the present example, and Table 2 is based on the conventional example. Comparing both graphs, the conventional speaker having only the cone diaphragm has a reproduction frequency band of f0 to 8 kHz as shown in Table 2. While a large peak is recognized in the middle and high end regions, a peak is hardly recognized in the speaker unit of the present invention having the second diaphragm 12 as a sub-cone, and it is understood that the output sound pressure level is stable.

FIG. 3 is a schematic view showing another embodiment of the speaker unit according to the present invention. This speaker unit is an example in which the cone diaphragm 1 is replaced with a straight type (conical cone) as shown in FIG. 1 and is a non-porous parabolic type (parabolic cone). The tip of the voice coil 4 is connected to the center of the bottom in a non-penetrating state. And the cone diaphragm 1
A diaphragm 12 having the same shape as that of FIG. 1 is connected in the same manner as the speaker unit of FIG.

A parabolic cone diaphragm 1 as shown in FIG. 3 is provided. A circular hole is formed in the center of the bottom to penetrate the front end of the voice coil 4, and a cap for covering the front end of the voice coil is formed on the inner peripheral surface. May be attached.
Further, instead of the straight or parabolic cone diaphragm 1, a paracurve (curved cone) as shown in FIG. 4 can be used. Further, the diaphragm 12 serving as a sub-cone (drive cone) has a larger diameter portion 12a than the cone diaphragm 1.
Can be provided on the inner peripheral surface side of the cone diaphragm 1 instead of being provided on the outer peripheral surface side of the cone diaphragm 1.

FIG. 5 shows an example of this. In the speaker unit of this example, a second diaphragm 12 is provided on the inner peripheral surface side of the cone diaphragm 1 instead of the cap 11 of FIG. The diaphragm 12 has, for example, a parabolic shape as shown in the drawing, and its bottom center is connected to the tip of the voice coil 4 with an adhesive or the like, and its upper opening edge is formed on the inner peripheral surface of the cone diaphragm 1. It is connected between the connection portion of the boil coil 4 and the edge 16. The diaphragm 12 serving as the cap can also suppress the distortion of the cone diaphragm 1 in the low frequency range, the divided vibration in the high frequency range, and the resonance, similarly to the above-described example.

In the embodiment shown in FIG. 5, for example, the cone diaphragm 1
Is formed of non-conductive paper or the like, and a lead wire 13 is connected to the peripheral surface thereof as shown in the figure. Also, when the cone diaphragm 1 is made of plastic or conductive metal which is easily thermally deformed,
The voice coil 4 without passing the lead wire 13 through the cone diaphragm 1
Directly from the outside.

Although the application examples of the present invention have been described in detail with reference to the drawings, the present invention is not limited to providing the second diaphragm on either the inside or the outside of the cone diaphragm, but on both sides thereof. You may do so. For example, as shown in FIG. 1, by extending the voice coil 4 to the back surface of the cap 11 and connecting it to the cap,
Can be used as a third diaphragm connecting the voice coil 4 and the cone diaphragm 1.

[0029]

As is apparent from the above description, according to the electrodynamic speaker unit of the present invention, the portion on the peripheral surface of the cone diaphragm constituting the base is supported by the second diaphragm, and the diaphragm is provided. And the voice coil drive the two locations of the cone diaphragm, so that distortion in the low range of the cone diaphragm, split vibration and resonance in the high range are suppressed, and the reproduction frequency band is greatly improved. In addition, since the resonance of the cone diaphragm is suppressed, the disturbance of the frequency characteristics is small, and the sound quality is hardly attached.

Further, since the strength of the cone diaphragm is increased by the provision of the second diaphragm, the maximum input of the speaker unit can be increased.

Further, since the second diaphragm is formed on the outer peripheral surface side of the cone diaphragm while being formed of an electrically insulating material, the input lead wire leading to the voice coil is externally connected via the diaphragm. It can be easily pulled out, and since the diaphragm blocks the heat conduction from the voice coil to the cone diaphragm, there is no danger of being thermally deformed by using a plastic cone diaphragm, and its durability is greatly improved. I do.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an electrodynamic loudspeaker unit according to the present invention.

FIG. 2 is a partial cross-sectional view showing a main part of the unit, partially cut away;

FIG. 3 is a schematic sectional view of a main part showing a second example of the present invention.

FIG. 4 is a schematic sectional view of a main part showing a third example of the present invention.

FIG. 5 is a schematic sectional view of a main part showing a fourth example of the present invention.

FIG. 6 is a sectional view showing a conventional speaker unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cone diaphragm 2 Vibration source 3 Magnetic circuit 4 Voice coil 10 Voice coil bobbin 11 Cap 12 Second diaphragm 13 Lead wire 15 Damper

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigekatsu Ochiai 3-12-12 Moriyacho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside (72) Inventor Mitsuo Komori 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Address F-term in JVC Co., Ltd. (reference) 5D012 AA03 BA07 BC02 CA05 CA10 DA01 EA04 FA02 GA01 5D016 AA09 AA15 GA01 HA01

Claims (2)

[Claims] 1. An electrodynamic speaker unit comprising a voice coil and a cone diaphragm connected to the voice coil, wherein a portion on the peripheral surface of the cone diaphragm is coaxial with the cone diaphragm. An electrodynamic loudspeaker unit comprising a second diaphragm connected to the speaker. 2. A second diaphragm connecting the cone diaphragm and the voice coil, wherein the second diaphragm has a conical shape made of an electrically insulating material,
The electrodynamic speaker unit according to claim 1, wherein the large-diameter portion is connected to the outer peripheral surface of the cone diaphragm, and the small-diameter portion is connected to the voice coil.