JP2000308184A - Loundspeaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply large magnetic force to a gap by improving the utilization efficiency of a magnet. SOLUTION: In a flange part 116B on the rear end side of a frame 116, a first plate 210 is arranged on the back side and continuously, a first magnet 220 magnetized in the axial direction of a center pole part 122C, a second plate 230, a second magnet 240 oppositely magnetized to the first magnet 220 and a base flange part 122A of a yoke 122 are successively arranged in the axial direction of the center pole part 122C. Besides, this magnetic circuit is surrounded with a magnetic shield cover 250. On the other hand, a third magnet 260 and a third plate 270 oppositely magnetized to the first magnet 220 are provided on the front side of the flange part 116B of the frame 116. Then, a voice coil 118 is arranged in a gap part 130A corresponding to the second plate 230.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cone type speaker device.

[0002]

2. Description of the Related Art FIG. 4 is a cross-sectional view showing a structure of a cone type speaker device using a general dynamic drive system. This speaker device has a voice coil bobbin 12 on an inner peripheral portion of a cone-shaped diaphragm (cone paper) 10 having a truncated cone shape.
The outer peripheral portion of the front end side (upper side in FIG. 4) is bonded, and a damper 14 is adhered to a middle outer peripheral portion of the bobbin 12. The voice coil bobbin 12 has a voice coil 18 mounted on the outer peripheral portion on the rear end side (the lower side in FIG. 4).

A dome-shaped cap 20 is provided at the center of the diaphragm 10 so as to cover the front end of the voice coil bobbin 12.
The center pole portion 22 </ b> C of the yoke 22 is inserted into the rear end of the voice coil bobbin 12. The frame 16 has a truncated conical shape arranged on the outer periphery of the diaphragm 10, and has a flange 16A bent outward at the front end thereof.
Is provided with a gasket 24. An inwardly bent flange portion (bottom plate) is provided on the rear end side of the frame 16.
16B are formed.

[0004] An arc-shaped edge portion 10 A is formed on the outer peripheral portion of the diaphragm 10 and is joined to the front end of the frame 16. An input terminal 26 is provided on the outer peripheral portion of the frame 16, and a lead wire (kinshi wire) 28 is stretched between the input terminal 26 and the diaphragm 10. A flange 30B on the rear end side of the frame 16 faces the voice coil 18 of the voice coil bobbin 12 and has a plate 30.
Is disposed on the rear end face of the plate 30.
2 are arranged. That is, the gap portion 30A is provided between the plate 30 and the center pole portion 22C of the yoke 22.
Are formed, and the voice coil 18 is arranged. The rear end of the yoke 22 has an outwardly facing flange 22.
A is provided, and the magnet 32 is positioned and mounted by a magnet guide 22B formed on the front surface of the flange portion 22A.

FIG. 5 is a sectional view showing the structure of a cone type speaker device provided with a cancel magnet 36 in the cone type speaker device shown in FIG. In the speaker device shown in FIG. 5, by providing a cancel magnet 36 having a polarity opposite to that of the magnet (main magnet) 32 on the rear surface side of the flange portion 22A of the yoke 22, the resonance sharpness at the lowest resonance frequency of the speaker can be achieved in a small device configuration. The lower the degree, the better the bass reproduction.

FIG. 6 is a sectional view showing the structure of a cone type speaker device provided with a shield cover 38 in addition to the cone type speaker device shown in FIG. The shield cover 38 is provided so as to be in close contact with the rear surface of the cancel magnet 36 and to cover the outer periphery of the magnet 32 and the plate 30 from the cancel magnet 36. By providing such a shield cover 38, a magnetic shield effect can be obtained against an external magnetic field, the magnetic flux in the gap of the magnetic circuit is increased, and the resonance sharpness at the lowest resonance frequency of the speaker is slightly reduced. Can be lowered.

FIG. 7 is a sectional view showing a structure in which the cone type speaker device shown in FIG. 6 is provided in a speaker box.
As shown in the figure, the cone type speaker device has a gasket 2
4, and is attached to the front opening 40A of the speaker box 40. The input terminal 26 of the cone type speaker device is connected to an input terminal 44 provided on the back of the speaker box 40 by a lead wire 42. A duct 46 and a duct opening 48 are formed below the speaker box 40.

FIG. 8 is a sectional view showing the structure of another cone type speaker device. Members common to those shown in FIGS. 4 to 6 are denoted by the same reference numerals, and description thereof is omitted. In this speaker device, the center pole portion 22C of the plate 50 and the yoke 22 is formed by a pair of magnets 52 and 54 disposed on the front and rear surfaces of the intermediate plate 50.
In this case, a stronger magnetic field is concentrated in the gap 50A between the two. The voice coil 18 is provided on the center pole portion 22C at a position corresponding to the gap portion 50A. In this structure, the magnetic force of the gap portion 50A decreases due to the presence of the gap portion 30A, but the magnetic force of the pair of magnets 52 and 54 is concentrated,
This is to increase the magnetic force of the gap 50A.

[0009]

However, in the above-mentioned conventional loudspeaker apparatus having an external magnet type magnetic circuit as shown in FIG. 4, the efficiency of use of the magnet is poor, and the power of the magnet is about 1 /. I only use about three. In the case where the cancel magnet is provided as shown in FIG. 5 and the case where the shield cover is provided as shown in FIG. 6, the magnetic force applied to the gap is reduced by up to 20% due to the reduction of the magnetic leakage. To some extent.
However, in terms of magnet utilization efficiency, if the cancellation magnet is the same size as the main magnet,
Since the magnetic force of the magnet is doubled and the magnetic force applied to the gap is 1.2 times, it is about 1/5.
However, the cancellation magnet is rarely the same size as the main magnet, and is usually slightly smaller. Further, as shown in FIG. 8, when the magnetic force of the gap is concentrated by a pair of magnets, the magnetic force of the gap 30A of the speaker device shown in FIG.
Three times the magnetic force can be obtained. In this case, the utilization efficiency of the magnet is about 1.15 / 3, which is slightly higher than 1/3.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a speaker device which can improve the utilization efficiency of a magnet and can apply a large magnetic force to a gap.

[0011]

According to the present invention, in order to achieve the above object, a cone-shaped diaphragm provided with a voice coil bobbin in a central portion is mounted on a frame, and the voice coil bobbin is provided on the back side of the cone-shaped diaphragm. A yoke having a center pole portion arranged coaxially is arranged, and a plate and a magnet are arranged on the outer periphery of the center pole portion to form a magnetic circuit, and between the center pole portion and the plate. In a speaker device in which a voice coil mounted on the voice coil bobbin is arranged in a formed gap portion, a first plate is arranged on a back side of a bottom plate provided on the frame, and the first plate is arranged following the first plate. The first magnet, the second plate, and the second plate, which are magnetized in the axial direction of the center pole portion, A second magnet that is opposite magnetized,
A bottom flange portion of the yoke and an axial direction of the center pole portion, a magnetic shield surrounding a magnetic circuit on a back side of the frame is further provided, and a front surface of a bottom plate provided on the frame is provided. A third magnet is disposed on the side of the third magnet, and a third plate is provided on the front side of the third magnet.

In the loudspeaker device of the present invention, three pairs of magnets and plates are sequentially arranged in the axial direction of the center pole portion to efficiently apply a magnetic force to the gap between the center pole portion and the plate, and Drive the coil bobbin. For example, when the third magnet is reversely magnetized with respect to the first magnet, the voice coil of the voice coil bobbin is arranged at a position corresponding to the second plate, so that the voice coil bobbin and the second plate can be connected to each other. The magnetic force is concentrated on one gap between them. Also,
When the third magnet is sequentially magnetized with respect to the first magnet, the voice coil of the voice coil bobbin is moved to the first magnet.
The magnetic force is concentrated on the two gaps between the voice coil bobbin and the first and second plates by arranging them at the position corresponding to the first plate and the position corresponding to the second plate.

With such a configuration, the magnetic force applied to the gap can be increased by effectively utilizing the magnetic force of the first to third magnets. For example, a magnetic force approximately four times less than that of the configuration shown in FIG. 4 can be applied to the gap portion, and the utilization efficiency of the magnet can be improved to about 1.4 / 3. Further, since the third magnet and the third plate are disposed on the front side of the bottom plate of the frame, that is, on the diaphragm side, the magnetic circuit disposed on the rear side of the bottom plate of the frame can be reduced in size. It can be configured and a compact structure can be obtained. Further, in the configuration of the present invention, since the voice coil bobbin can be lengthened in the axial direction, the resonance sharpness at the lowest resonance frequency can be reduced by effectively utilizing the resistance of the airflow film in the gap between the voice coil bobbin and the center pole portion. In addition, the airflow film in the gap between the voice coil bobbin and the center pole portion is used as an air bearing, so that the vibration of the voice coil bobbin can be obtained smoothly, and the vibration of the diaphragm (reduction in rolling) can be prevented. Can radiate bass.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a speaker device according to the present invention will be described below. FIG. 1 is a sectional view showing a first structural example of a speaker device according to the present invention. In this speaker device, a front end side (upper side in FIG. 1) outer periphery of a voice coil bobbin 112 is joined to an inner periphery of a cone-shaped diaphragm (cone paper) 110 having a truncated cone shape,
A damper 114 is bonded to an outer peripheral portion on the front end side of the bobbin 112, and an outer peripheral portion of the damper 114 is joined to a third plate 270 described later. The voice coil bobbin 112 has a voice coil 118 mounted on the outer peripheral portion on the rear end side (the lower side in FIG. 1).

At the center of the diaphragm 110, a dome-shaped cap 120 is provided so as to cover the front end of the voice coil bobbin 112. At the rear end of the voice coil bobbin 112, a center pole portion 122C of a yoke 122 is provided. Is inserted. The frame 116 has a truncated conical shape arranged on the outer periphery of the diaphragm 110, and has a flange 116A bent outward at the front end thereof. A gasket 124 is provided on the flange 116A. ing. An inwardly bent flange portion (bottom plate) 116B is formed on the rear end side of the frame 116.
An arc-shaped edge portion 110A is provided on the outer peripheral portion of the diaphragm 110.
Is formed and joined to the front end of the frame 116. An input terminal 126 is provided on the outer periphery of the frame 116, and a lead wire (kinshi wire) 128 is stretched between the input terminal 126 and the diaphragm 110.

A first plate 210 is disposed on the rear side (lower side in FIG. 1) of the flange portion 116B on the rear end side of the frame 116, and following the first plate 210, The first magnet 220 and the second magnet 220
The plate 230, the second magnet 240, and the bottom flange portion 122A of the yoke 122 are sequentially arranged in the axial direction of the center pole portion 122C. The first magnet 220 is magnetized in the axial direction of the center pole portion 122C, and in this example, the first plate 210 side is N
The pole and the second plate 230 side are magnetized to the S pole.
The first magnet 220 is fixed to the first plate 210 and the second plate 230 by bonding. Second
Is magnetized reversely with respect to the first magnet 220, and in this example, the second plate 230
The side is magnetized to the S pole and the bottom flange portion 122A is magnetized to the N pole. The second magnet 240 is connected to the second plate 2
30 and the second bottom flange portion 122A are fixed by bonding. Further, a magnet guide 122B is formed on the bottom flange portion 122A, and performs positioning and the like when configuring the above-described magnetic circuit.

A magnetic shield cover 250 is provided on the first plate 210. The magnetic shield cover 250 includes a magnetic circuit on the back side of the frame 116, that is, the first plate 210, the first magnet 220, the second plate 230, and the second magnet 2.
40 and the yoke 122 to provide a magnetic shield. The magnetic shield cover 250 is fixed to the first plate 210 by bonding.

On the other hand, on the front side of the flange portion (bottom plate) 116B of the frame 116, a third magnet 260 is provided.
A third plate 270 is provided on the front side of the. The third magnet 260 is reversely magnetized with respect to the first magnet 220, and in this example, the first plate 21
The 0 side is magnetized to the N pole, and the third plate 270 side is magnetized to the S pole. The third magnet 260 is connected to the third plate 2
70 and the flange portion 116B. The voice coil 1 of the voice coil bobbin 112
Reference numeral 18 is disposed at a position corresponding to the second plate 230.

A drive signal is supplied to the voice coil 118 via a lead wire 128 or the like, and the voice coil 118 is inserted into a gap 130A formed between the center pole portion 122C and the second plate 230. Vibrates to vibrate the diaphragm 110 via the voice coil bobbin 112. That is, in this example, the gap portion 130B formed between the center pole portion 122C and the first plate 210, and the gap portion 1 formed between the center pole portion 122C and the third plate 270.
No voice coil is arranged in 30C.

When assembling the speaker device as described above, first, the second magnet 240 is positioned and adhered and fixed to the flange portion 122A of the yoke 122 by the magnet guide 122B, and the second plate is attached to the second magnet 240. 230 is adhered and fixed. At this time, a gap guide is interposed between the center pole portion 122C and the second plate 230, and the positioning is performed while fixing. On the other hand, the flange portion 116B of the frame 116 and the first
After the first and second plates 210 and 210 are joined by caulking or the like, the first
The first magnet 220 is bonded and fixed to the plate 210 of FIG. After the second magnet 240 and the first magnet 220 are reversely magnetized, the center pole 1
With the gap guide interposed between 22C and the first plate 210, the second plate 230 and the first magnet 220 are positioned and bonded and fixed.

After positioning and bonding and fixing the third magnet 260 and the third plate 270, the third magnet 260 is reversely magnetized with respect to the first magnet 220, and the center pole 122C Third plate 27
0 with the gap guide interposed between the third magnet 260 and the flange 116 of the frame 116.
B is adhered and fixed. After this, the magnetic shield cover 250
Also, the attachment of the voice coil bobbin 112, the diaphragm 110, and the like are sequentially performed.

In the speaker device having the above configuration, 3
Magnetic force by the two magnets 220, 240, 260
By concentrating on one gap 130A, the magnetic force applied to gap 130A can be increased by effectively utilizing the magnetic forces of first to third magnets 220, 240, and 260. Explaining this principle, first, in the magnetic circuit shown in FIG. 1, there are three effective magnetic paths passing through the gap 130A. The first is the N of the second magnet 240
From the pole, the flange portion 122A of the yoke 122, the center pole portion 122C, the gap portion 130A, and the second
From the plate 230 of the second magnet 240,
This is a closed circuit that further reaches the N pole.

Second, the N of the first magnet 220
From the pole to the first plate 210 and the center pole part 122C
Through the gap 130B between the second plate 2
Gap portion 13 between the center pole portion 30 and the center pole portion 122C
This is a closed circuit that passes through 0A and extends from the second plate 230 to the S pole of the first magnet 220 and further to the N pole. Third, from the N pole of the third magnet 260 to the center pole 122C via the gap 130B, from the gap 130A to the S plate of the first magnet 220 via the second plate 230, and from the S pole of the first magnet 220 to the third magnet. It is a closed circuit reaching the N pole of 260.

With such three magnetic paths, an extremely large magnetic force is applied to the gap 130A in which the voice coil 118 is disposed. That is, the magnetic force of the gap portion 130A obtained by adding the above magnetic paths is about 2.5 times that of the conventional example shown in FIG. Also, the magnetic force generated in the plate 230 between the reversely magnetized magnets 220 and 240 is about 1.5 times the magnetic force due to the magnetic path, so the magnetic force applied to the gap 130A is about 3.7 times. . Therefore, according to the structure of the present example, it is possible to apply a magnetic force about 3.7 times that of the configuration shown in FIG. 4 to the gap portion 130A, and it is possible to improve the magnet utilization efficiency to about 1.4 / 3.

Further, since the third magnet 260 and the third plate 270 are arranged on the front side of the bottom plate 116B of the frame 116, that is, on the diaphragm 110 side, they are arranged on the back side of the bottom plate 116B of the frame 116. The magnetic circuit can be configured without increasing the size, and a compact structure can be obtained. Further, in the configuration of this example, since the voice coil bobbin 112 can be lengthened in the axial direction, the resonance sharpness at the lowest resonance frequency can be reduced by effectively utilizing the resistance of the airflow film in the gap between the voice coil bobbin 112 and the center pole portion 122C. Can be smaller. In addition, by using the airflow film in the gap between the voice coil bobbin 112 and the center pole portion 122C as an air bearing, smooth vibration of the voice coil bobbin can be obtained, and furthermore, vibration of the diaphragm (reduction in rolling) can be prevented. In particular, when a speaker dedicated to bass is used, it is possible to radiate powerful and clear bass of good quality.

FIG. 2 shows a second embodiment of the speaker device according to the present invention.
It is sectional drawing which shows the structural example of. The same components as those of the speaker device shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In the example shown in FIG.
0 is reversely magnetized with respect to the first magnet 220, but in this example, the third magnet 260 </ b> A is magnetized with respect to the first magnet 220. In this example, two gap portions 1 are provided in the voice coil bobbin 112.
Voice coil 118A, 1 corresponding to 30A, 130B
18B.

In such a configuration, although the structure of the magnetic path is different from that of the example shown in FIG.
0, 240, 260 A magnetic force is applied to the two gap portions 130.
The driving of the diaphragm 110 by the voice coils 118A and 118B is realized by a sufficient magnetic force concentrated on the A and 130B. Also in this example, the third magnet 260A and the third plate 270 are
6, the front side of the bottom plate 116B, that is, the diaphragm 110
Side plate, the bottom plate 116 of the frame 116
The magnetic circuit disposed on the back side of B can be configured without increasing the size, and a compact structure can be obtained.

Further, in the configuration of this embodiment, since the voice coil bobbin 112 can be lengthened in the axial direction, the resonance at the lowest resonance frequency can be effectively utilized by effectively utilizing the resistance of the airflow film in the gap between the voice coil bobbin 112 and the center pole portion 122C. Sharpness can be reduced. Voice coil bobbin 1
By using the airflow film in the gap between the center pole 12 and the center pole portion 122C as an air bearing, smooth vibration of the voice coil bobbin can be obtained, and furthermore, vibration of the diaphragm (reduction in rolling) can be prevented. When used as a speaker, it is possible to radiate powerful and clear bass of good quality.

FIG. 3 is a sectional view showing a structure in which the speaker device shown in FIG. 2 is provided in a speaker box. As shown in the figure, the speaker device is mounted on the front opening 140A of the speaker box 140 via the gasket 124. The input terminal 126 of the speaker device is connected to an input terminal 144 provided on the back of the speaker box 140 via a lead wire 142. A duct 146 and a duct opening 148 are formed below the speaker box 140. FIG. 3 shows an example in which the speaker device shown in FIG. 2 is provided in a speaker box.
Similarly, it goes without saying that the speaker device shown in FIG. 1 is provided in the speaker box.

[0030]

As described above, in the speaker device of the present invention, the first plate is arranged on the back side of the bottom plate provided on the frame holding the cone-shaped diaphragm, and the first plate is connected to the first plate. A first magnet magnetized in the axial direction of the center pole portion, a second plate,
A second magnet reversely magnetized to the first magnet and a bottom flange portion of the yoke are sequentially arranged in the axial direction of the center pole portion, and a magnetic circuit surrounding a magnetic circuit on the back side of the frame. Providing a shield body, disposing a third magnet on the front side of the bottom plate provided on the frame, and further providing a third plate on the front side of the third magnet,
A magnetic force is applied to the gap of the magnetic circuit by the three magnets, and the voice coil of the voice coil bobbin disposed in the gap is driven.

Therefore, the magnetic force applied to the gap can be increased by effectively utilizing the magnetic force of the first to third magnets, and an efficient speaker device can be provided. Further, since the third magnet and the third plate are disposed on the front side of the bottom plate of the frame, that is, on the diaphragm side, the magnetic circuit disposed on the rear side of the bottom plate of the frame can be reduced in size. It can be configured and a compact structure can be obtained. Further, since the voice coil bobbin can be lengthened in the axial direction in the above configuration, the resonance sharpness at the lowest resonance frequency can be reduced by effectively using the resistance of the airflow film in the gap between the voice coil bobbin and the center pole portion. In addition, by using the airflow film in the gap between the voice coil bobbin and the center pole portion as an air bearing, smooth vibration of the voice coil bobbin can be obtained, and furthermore, vibration of the diaphragm (reduction in rolling) can be prevented.
Good quality bass can be radiated.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first structural example of a cone type speaker device according to the present invention.

FIG. 2 is a sectional view showing a second structural example of the cone type speaker device according to the present invention.

FIG. 3 is a cross-sectional view showing a structural example in which the cone-type speaker device shown in FIG. 2 is arranged in a speaker box.

FIG. 4 is a cross-sectional view showing a structure of a cone type speaker device using a general dynamic driving method.

5 is a cross-sectional view showing a structure of a cone type speaker device provided with a cancel magnet in the cone type speaker device shown in FIG.

6 is a cross-sectional view showing the structure of a cone-type speaker device provided with a shield cover in addition to the cone-type speaker device shown in FIG.

7 is a cross-sectional view showing a structure in which the cone-type speaker device shown in FIG. 6 is provided in a speaker box.

FIG. 8 is a cross-sectional view showing the structure of another conventional cone-type speaker device.

[Explanation of symbols]

110: cone type diaphragm, 112: voice coil bobbin, 114: damper, 116: frame, 116
B: Flange (bottom plate), 122: Yoke, 12
2A: bottom flange portion, 122C: center pole portion, 210: first plate, 220: first magnet, 230: second plate, 240: second magnet, 250: magnetic Shield cover, 260 ...
... Third magnet, 270... Third plate.

Claims (5)

[Claims] 1. A cone type diaphragm having a voice coil bobbin provided at a center portion is mounted on a frame, and a yoke having a center pole portion coaxially arranged with the voice coil bobbin is disposed on the back side of the cone type diaphragm. A voice coil mounted on the voice coil bobbin in a gap formed between the center pole and the plate, and a plate and a magnet are arranged on the outer periphery of the center pole to form a magnetic circuit. In the speaker device in which the coil is disposed, a first plate is disposed on a back side of a bottom plate provided in the frame, and the first plate is magnetized in an axial direction of the center pole portion following the first plate. A first magnet, a second plate, a second magnet reversely magnetized with respect to the first magnet, A surface flange portion is sequentially arranged in the axial direction of the center pole portion, and a magnetic shield body surrounding a magnetic circuit on the rear side of the frame is further provided; and a magnetic shield body is provided on a front side of a bottom plate provided on the frame. 3. The speaker device according to claim 1, wherein a third plate is provided on a front side of the third magnet. 2. The method according to claim 1, wherein the third magnet is reversely magnetized with respect to the first magnet, and a voice coil of the voice coil bobbin is arranged at a position corresponding to the second plate. 2. The speaker device according to 1. 3. The third magnet is sequentially magnetized with respect to the first magnet, and a voice coil of the voice coil bobbin is positioned at a position corresponding to the first plate and at a position corresponding to the second plate. The speaker device according to claim 1, wherein the speaker device is arranged in a speaker. 4. The speaker device according to claim 1, wherein a damper is provided between the third plate and the voice coil bobbin. 5. The speaker device according to claim 1, wherein the speaker device is a dynamic speaker that drives the diaphragm by supplying a drive signal to the voice coil.