JPH09307995A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the speaker where rubbing caused by an insufficient gap hardly takes place. SOLUTION: The speaker is made up of a thin and long main frame 101 to which an outer circumferential part of a common diaphragm 102 resulting from integrating a plurality of cones arranged side by side is fitted, a subframe 150 fitted to the main frame 101 and made of a material with a smaller linear expansion coefficient than that of a material of the main frame 101, and a plurality of magnetic circuits 114, 115 driving a plurality of voice coils and fitted to the subframe 150.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker in which a plurality of voice coils are mounted on a common diaphragm in which a plurality of cones are continuously arranged and integrated, that is, a so-called multi-point drive type speaker.

Recently, speakers installed in televisions, display devices for multimedia computers, etc., have a limited installation space due to an increase in screen size, and narrow and narrow speakers are used.

In such an elongated speaker,
Driving at one point in the center of the diaphragm causes split resonance in the long-axis direction to deteriorate the sound quality, and thus a multi-point drive type speaker is preferable.

[0004]

2. Description of the Related Art Next, a conventional example will be described with reference to the drawings.
FIG. 11 is a plan view of a conventional multi-point drive type speaker, FIG.
2 is a sectional view taken along the line AA in FIG. 11, FIG.
11 is a cross-sectional view taken along the cutting line BB in FIG. 11, FIG. 14 is an enlarged view of the cross-sectional portion in FIG. 13, FIG. 15 is a configuration diagram of the first and second magnetic circuits in FIG. 11, and FIG.
FIG. 6 is a diagram for explaining the connection between the first voice coil bobbin and the second voice coil bobbin in FIG.

In these figures, 1 is an elongated resin frame. The flange 1a of the frame 1 has a common diaphragm 2 in which a plurality of cones are continuously arranged and integrated.
The outer peripheral portion of is attached via the edge 3. Further, a gasket 4 is provided on the flange portion 1 a of the frame 1.

The diaphragm 2 is provided with a first voice coil bobbin 7 around which a voice coil 6 is wound, and a second voice coil 8 (not shown) in the same winding direction as the voice coil 6. One end of the voice coil bobbin 9 is attached. Further, the open ends of the first and second voice coil bobbins 7 and 9 on the diaphragm 2 side are sealed with caps 10 and 11.

Further, the first and second voice coil bobbins 7 and 9 are attached to the first and second voice coil bobbins 7 and 9 by means of dampers 12 and 13 whose inner peripheral portions are attached to the first and second voice coil bobbins 7 and 9 and whose outer peripheral portion is attached to the frame 1. Are attached to the frame 1.

The frame 1 is provided with first and second magnetic circuits 14 and 15 so as to face the first and second voice coil bobbins 7 and 9, respectively. First magnetic circuit 1
4 is a cylindrical portion 1 fitted in the first voice coil bobbin 7.
6a, a first yoke 16 composed of a collar portion 16b, and a first yoke 16 provided on the collar portion 16b of the first yoke 16.
The circular magnet 17 arranged at a distance from the circumferential surface of the cylindrical portion 16a of the yoke 16, and the cylindrical portion 16a of the first yoke 16 provided on the magnet 17.
Is provided on the annular second yoke 18 and the flange portion 16b of the first yoke 16 which are arranged with a gap (magnetic gap G) from the circumferential surface of In the opposite direction, the canceling magnet 19 for reducing the leakage magnetic flux is brought into contact with the second yoke 18 and the canceling magnet 19, and the first yoke 16, the magnet 17,
It comprises a second yoke 18 and an outer yoke 20 provided so as to cover the canceling magnet 19.

Similarly, the second magnetic circuit 15 has a columnar portion 26a fitted in the second voice coil bobbin 9 and a collar portion 2.
The first yoke 26 composed of 6b and the first yoke 2
6 is provided on the flange portion 26b of the first yoke 26, is arranged at a distance from the circumferential surface of the cylindrical portion 26a of the first yoke 26, and is magnetized in the same direction as the magnet 17 of the first magnetic circuit 14. Ring-shaped magnet 27, and a second ring-shaped magnet 27 provided on the magnet 27 with a gap (magnetic gap G) from the circumferential surface of the cylindrical portion 26a of the first yoke 26. Yoke 28 and the brim portion 26 of the first yoke 26.
a canceling magnet 29, which is provided in b and whose magnetizing direction is opposite to that of the magnet 17, and a second yoke 28 and a canceling magnet 29, the first yoke 26, the magnet 27, the second yoke 28, The outer yoke 30 is provided so as to cover the canceling magnet 29.

The voice coils 6 and 8 of the first and second voice coil bobbins 7 and 9 are disposed in the magnetic gaps G of the magnetic circuits 14 and 15, respectively. Two terminals 32 and 33 are provided at the center of the frame 1. And
The lead wire 34 is connected to the terminal 32 from one end of the voice coil 6 of the first voice coil bobbin 7, the lead wire 35 is connected to the terminal 33 from the other end, and the voice coil 8 of the second voice coil bobbin 9 is Leader line 36 from one end
To the terminal 32, and the lead wire 37 from the other end to the terminal 33.
Respectively connected to.

Since the winding directions of the voice coil 6 of the first voice coil bobbin 7 and the voice coil 8 of the second voice coil bobbin 9 are the same, one of the voice coil 6 and the voice coil 8 has the same polarity in order to match the polarities of the voice coils. The lead wires, in the present conventional example, the lead wires 36 and 37 are folded back near the voice coil 7 and connected to the voice coil 8.

Then, when a drive current is passed through the voice coil 6 of the first voice coil bobbin 7 and the voice coil 8 of the second voice coil bobbin 9 via the terminals 32 and 33, the first and second voice coil bobbins 7 and 9 perform a piston motion, the diaphragm 2 vibrates in that direction, and the diaphragm 2
A sound wave is emitted from.

[0013]

However, the speaker having the above structure has the following problems. (1) To reduce the magnetic flux leakage, and further for cost reduction,
The frame 1 is made of resin. Generally, the coefficient of linear expansion of resin is larger than that of metal. For example, SPC (cold rolled steel sheet) as an example of metal is 1.18 × 10 ^-5 cm / cm / ° C, whereas ABS resin as an example of resin is 3.75 × 10 ^-5 cm /
cm / ° C. On the other hand, the linear expansion coefficient of the diaphragm 2 is almost 0.
It is.

Therefore, due to the heat generated in the magnetic circuit and the increase in the ambient temperature around the speaker, only the frame 1 thermally expands, and the first and second voice coil bobbins 7 and 9 provided on the diaphragm 2 are separated. There is a problem that a phenomenon of hitting the magnetic gap G of the first and second magnetic circuits 14 and 15 on the frame 1 side, that is, so-called “gap rubbing” occurs.

(2) The diameters of the dampers 12 and 13 are determined by the width of the elongated frame 1, and the diameters of the dampers 12 and 13 cannot be set large. If the diameters of the dampers 12 and 13 are limited, the amplitude cannot be made large, the reproduction band is narrow, and the distortion is increased.

(3) The first and second magnetic circuits 14 and 15 are attached to the resin frame 1 by a method such as adhesion, but the number of steps is large and the reliability of the attachment strength is poor. There is a point.

(4) The first and second magnetic circuits 14 and 15 are provided with canceling magnets 19 and 29, respectively, in order to reduce the leakage magnetic flux. Is leaking from. In a multi-point drive speaker, a plurality of magnetic circuits are provided, and the amount of magnetic flux leaking increases.

In particular, when it is built in a television or a computer display, the amount of magnetic flux leakage is severely limited, so that a magnetic shielding member is additionally required, which causes a problem of increased cost.

The present invention has been made in view of the above problems, and an object thereof is to prevent gap scraping even under high temperature, to set a large diameter of a damper, and to easily and reliably form a magnetic circuit in a frame. It is to provide a speaker that can be attached to a speaker and that has less magnetic flux leakage.

[0020]

Means for Solving the Problems A first method for solving the above problems is described below.
The invention of claim 1, in a speaker in which a plurality of voice coils are attached to a common diaphragm in which a plurality of cones are arranged in series and integrated, and an elongated main frame to which an outer peripheral portion of the diaphragm is attached, and the main frame. A subframe made of a material having a linear expansion coefficient smaller than that of the material of the main frame; and a plurality of magnetic circuits attached to the subframe and driving the plurality of voice coils. is there.

Since the voice coil is provided on the diaphragm having almost no thermal expansion and the magnetic circuit is provided on the sub-frame made of a material having a linear expansion coefficient smaller than that of the material of the main frame, the gap scraping of the voice coil is performed. Can be reduced.

In a second aspect of the invention, in the first aspect, the main frame is made of resin and the sub frame is made of metal. Generally, the linear expansion coefficient of metal is smaller than the linear expansion coefficient of resin, so that the gap rubbing of the voice coil can be prevented.

ABS resin is an example of a particularly preferable resin, and SPC (cold rolled steel sheet) is a metal. In a third aspect of the invention, in the second aspect of the invention, when the subframe is made of metal, the magnetic circuit and the subframe are attached using "caulking".

By using the "caulking", the magnetic circuit and the subframe can be easily and securely attached. In a fourth aspect based on the first to third aspects, a hole is formed in a side surface of the main frame on the long width side, and an extension portion extending to a vicinity of an outer wall side opening of the hole of the main frame is provided. An outer peripheral portion of a damper provided on the subframe and having an inner peripheral portion attached to the diaphragm is attached to an extending portion of the subframe.

Since the outer peripheral part of the damper is attached to the extending part of the sub-frame located outside the main frame,
The diameter of the damper can be set to a large value, the playback band is widened, and distortion is reduced.

According to a fifth aspect of the present invention, in a speaker in which a plurality of voice coils are attached to a common diaphragm in which a plurality of cones are connected in series and integrated, a plurality of magnetic circuits for driving the voice coils are arranged adjacent to each other. The circuit is magnetized in the opposite direction.

By setting the magnetizing directions of the adjacent magnetic circuits to be opposite to each other, the magnetic fluxes leaking from the respective magnetic circuits are canceled each other and the magnetic flux leaking from the speaker is reduced.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is a plan partial cross-sectional view of a speaker of a multi-point drive system according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the cutting line CC in FIG. 1, and FIG. 3 is a cross-sectional view taken along the cutting line DD in FIG. 4 is an enlarged view of a cross-sectional portion in FIG. 3, FIG. 5 is a perspective view of the main frame and sub-frame in FIG. 1, FIG. 6 is a configuration diagram of the first and second magnetic circuits in FIG. 1, and FIG. FIG. 6 is a diagram for explaining the connection between the first voice coil bobbin and the second voice coil bobbin in FIG.

In these figures, reference numeral 101 designates an elongated resin frame (ABS resin in this embodiment).
In the flange portion 101a of the main frame 101,
A common diaphragm 102 in which a plurality of cones are arranged in series and integrated.
The outer peripheral portion of is attached via the edge 103.
Further, a gasket 104 is provided on the flange portion 101a of the main frame 101.

On the diaphragm 102, a first voice coil bobbin 107 around which a voice coil 106 is wound, and a voice coil 108 in the same winding direction as the voice coil 106 are wound.
Second voice coil bobbin 10 provided with (not shown)
9 and one end is attached. Further, the diaphragm 1 of the first and second voice coil bobbins 107, 109
The open end on the 02 side is sealed with caps 110 and 111.

The lower part of the main frame 101 is made of metal.
A sub-frame 150 (SPC in this embodiment) is attached. Then, holes 101b and 101c for attaching the magnetic circuit are formed on the bottom surface of the main frame 101, and the main frame 10 is provided on the sub frame 150.
Holes 150a, 150 facing the first holes 101b, 101c
b is formed.

Further, square holes 101d and 101e are formed on one side surface of the main frame 101 on the long width side, and square holes 101f and 101g are also formed on the other side surface. The sub-frame 150 is formed with extension parts 150c to 150f extending to the openings on the outer wall side of the rectangular holes 101d, 101e, 101f, 101g of the main frame 101. And each extension part 150c-150f
Bend portions 150g to 150j that are bent in a direction away from the outer wall of the main frame 101 are formed at the tip of the.

First and second voice coil bobbins 10
Inner peripheral portions of dampers 112 and 113 are attached to 7,109. Of the outer peripheral parts of the dampers 112 and 113,
The portion facing the narrow side surface of the main frame 101 is a damper mounting portion 1 formed in the main frame 101.
The portion attached to 01h and facing the wide side surface of the main frame 101 is the extension portion 15 of the sub frame 150.
Bent part 150g formed at each tip of 0c to 150f
It is attached to 150j.

On the sub-frame 150, facing the first and second voice coil bobbins 107, 109,
The first and second magnetic circuits 114 and 115 are attached by a "staking" method.

The first magnetic circuit 114 is provided on the cylindrical portion 116a fitted into the first voice coil bobbin 107, the first yoke 116 including the collar portion 116b, and the collar portion 116b of the first yoke 116. And an annular magnet 117 disposed at a distance from the circumferential surface of the cylindrical portion 116a of the first yoke 116, and the cylindrical portion 1 of the first yoke 116 provided on the magnet 117.
An annular second yoke 118 is provided with a gap (magnetic gap G) with respect to the circumferential surface of 16a, and a flange portion 116b of the first yoke 116 is provided.
7, the direction of magnetization is opposite to that of the canceling magnet 119 for reducing the leakage magnetic flux, and the second yoke 118 and the canceling magnet 119 are brought into contact with each other, and the first yoke 116, the magnet 117, and the second yoke 118, The outer yoke 120 is provided so as to cover the canceling magnet 119.

Similarly, the second magnetic circuit 115 has a cylindrical portion 126a fitted in the second voice coil bobbin 109,
A first yoke 126 including a flange portion 126b, and a first yoke 126 provided on the flange portion 126b of the first yoke 126.
The annular magnet 127, which is arranged at a distance from the circumferential surface of the cylindrical portion 126a of the yoke 126, has a magnetization direction opposite to that of the magnet 117 of the first magnetic circuit 114.
And the first yoke 1 provided on the magnet 127.
An annular second yoke 128 which is arranged with a gap (magnetic gap G) from the circumferential surface of the cylindrical portion 126a of 26.
And provided on the collar portion 126b of the first yoke 126,
The canceling magnet 129, which is magnetized in the opposite direction to the magnet 117, comes into contact with the second yoke 128 and the canceling magnet 129, and the first yoke 12
6, a magnet 127, a second yoke 128, and an outer yoke 130 provided so as to cover the canceling magnet 129.

The voice coils 106 and 108 of the first and second voice coil bobbins are disposed in the magnetic gap G of each magnetic circuit 114 and 115. Two terminals 132 and 133 are provided at the center of the main frame 101. Then, the first voice coil bobbin 107
Lead wire 134 from one end of voice coil 106 of
To the terminal 132, the lead wire 135 from the other end to the terminal 133, and the lead wire 136 from one end of the voice coil 107 of the second voice coil bobbin 109 to the terminal 132 and the other end. Line 137 is terminal 13
3 are connected to each.

In the present embodiment, the magnetizing direction of the magnet 117 of the first magnetic circuit 114 and the magnetizing direction of the magnet 127 of the second magnetic circuit 115 are opposite to each other. Since the winding directions of the voice coil 106 arranged in the magnetic gap G of the magnetic circuit 114 and the voice coil 108 arranged in the magnetic gap G of the second magnetic circuit 115 are the same, the drawer explained in the conventional example. No need to fold lines.

Then, through the terminals 132 and 133, the first
Voice coil 106 of the voice coil bobbin 107 of
When a drive current is applied to the coil 108 of the second voice coil bobbin 109, the first and second voice coil bobbins 1
07 and 109 perform piston movement, the diaphragm 102 vibrates in that direction, and sound waves are emitted from the diaphragm 102.

According to the above structure, the following effects can be obtained. (1) The first and second magnetic circuits 114 and 115 are made of SPC, which is a material having a coefficient of linear expansion smaller than that of ABS resin, which is a material of the main frame 101, and the subframe 15 made of SPC.
Since it is provided at 0, the first and second magnetic circuits 11
It is possible to reduce the gap scraping of the 4,115 voice coils 106, 108.

(2) First and second magnetic circuits 114, 11
5 is attached to the sub-frame 150 by "staking", the first and second magnetic circuits 114, 115 are attached.
The subframe 150 is easily and securely attached.

(3) Of the outer peripheral portions of the dampers 112 and 113, the portion facing the wide side surface of the main frame 101 is the bent portion 150g formed at each tip of the extended portions 150c to 150f of the subframe 150. By mounting the damper 112, 113, the diameters of the dampers 112 and 113 can be set large, the reproduction band is widened, and the distortion is reduced.

(4) First and second magnetic circuits 114, 11
By setting the magnetization directions of 5 to the opposite directions, the magnetic fluxes leaking from the magnetic circuits cancel each other out, and the magnetic fluxes leaking from the speaker can be reduced.

[0044]

EXAMPLES The inventors of the present application conducted the following experiments in order to confirm the effects of the present invention. (1) The distortion frequency characteristics of the speaker of the embodiment and the speaker described in the conventional example were measured. FIG. 8 is a diagram showing the distortion frequency characteristics of the speaker of the embodiment and the speaker of the conventional example, the solid line shows the embodiment example, and the broken line shows the conventional example.

As can be seen from FIG. 8, it was confirmed that the distortion was significantly reduced in all bands. (2) The sound pressure frequency characteristics of the speaker of the embodiment and the speaker described in the conventional example were measured. FIG. 9 is a diagram showing sound pressure frequency characteristics of the speaker of the embodiment and the speaker of the conventional example, the solid line shows the embodiment example, and the broken line shows the conventional example.

As can be seen from FIG. 9, the reproduction band, in particular,
It was confirmed that the bass range became wider. (3) In the loudspeaker of the embodiment, the leakage magnetic flux density when the magnetization directions of the first magnetic circuit 114 and the second magnetic circuit 115 are changed, and the leakage magnetic flux density of each of these magnetic circuits are measured. The results are shown in FIG.

As can be seen from FIG. 10, when the magnetization directions of the first magnetic circuit 114 and the second magnetic circuit are opposite to each other, the leakage magnetic flux density is smaller than that in the case of only one magnetic circuit. It was confirmed that the leakage magnetic flux density was the smallest.

[0048]

As described above, according to the present invention, the following effects can be obtained. (1) Speaker of the first invention In a speaker in which a plurality of voice coils are attached to a common diaphragm in which a plurality of cones are connected in series and integrated, a slender main frame to which an outer peripheral portion of the diaphragm is attached A subframe made of a material having a linear expansion coefficient smaller than that of the material of the main frame, and a plurality of magnetic circuits attached to the subframe and driving the plurality of voice coils; Since the voice coil is provided on the diaphragm with almost no thermal expansion, and the magnetic circuit is provided on the sub-frame made of a material having a linear expansion coefficient smaller than that of the material of the main frame, the voice coil is The gap rubbing can be reduced.

(2) Speaker of the second invention In the first invention, the main frame is made of resin and the sub frame is made of metal.

Since the coefficient of linear expansion of metal is generally smaller than that of resin, gap rubbing of the voice coil can be prevented. ABS resin is an example of a particularly preferable resin, and SPC (cold rolled steel sheet) is a metal.

(3) Speaker of the third invention In the second invention, when the sub-frame is made of metal, the magnetic circuit and the sub-frame are attached using "caulking".

By using the "caulking", the attachment of the magnetic circuit and the sub-frame is simple and reliable. (4) The speaker of the fourth invention. In the first to third inventions, a hole is bored in the side surface of the main frame on the long width side, and the speaker is extended to the vicinity of the outer wall side opening of the hole of the main frame. The projecting portion is provided on the subframe, and the outer peripheral portion of the damper, the inner peripheral portion of which is attached to the diaphragm, is attached to the extending portion of the subframe.

Since the outer peripheral portion of the damper is attached to the extending portion of the sub-frame located outside the main frame,
The diameter of the damper can be set to a large value, the playback band is widened, and distortion is reduced.

(5) Speaker of the fifth invention In a speaker in which a plurality of voice coils are attached to a common diaphragm in which a plurality of cones are arranged in series and integrated, a plurality of magnetic circuits for driving the voice coils are provided. By setting the magnetization directions of the adjacent magnetic circuits to be opposite to each other, the magnetic fluxes leaking from the magnetic circuits are canceled each other and the magnetic flux leaking from the speaker is reduced.

[Brief description of drawings]

FIG. 1 is a plan partial cross-sectional view of a multipoint drive type speaker according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the section line CC in FIG.

FIG. 3 is a sectional view taken along a cutting line DD in FIG.

FIG. 4 is an enlarged view of a cross section of FIG.

FIG. 5 is a perspective view of a main frame and a sub frame in FIG.

FIG. 6 is a configuration diagram of first and second magnetic circuits in FIG. 1.

7 is a first voice coil bobbin and a second voice coil bobbin in FIG.
FIG. 6 is a diagram for explaining the connection of the voice coil bobbin of FIG.

FIG. 8 is a diagram showing distortion frequency characteristics of the speaker of the embodiment and the speaker of the conventional example.

FIG. 9 is a diagram showing sound pressure frequency characteristics of the speaker of the embodiment and the speaker of the conventional example.

FIG. 10 is a diagram showing the leakage magnetic flux density when the magnetization directions of the first magnetic circuit and the second magnetic circuit are changed, and the leakage magnetic flux density of these magnetic circuits alone in the speaker of the embodiment. is there.

FIG. 11 is a plan view of a conventional multi-point drive speaker.

12 is a cross-sectional view taken along the section line AA in FIG.

13 is a cross-sectional view taken along the cutting line BB in FIG.

FIG. 14 is an enlarged view of a cross section of FIG.

FIG. 15 is a configuration diagram of first and second magnetic circuits in FIG. 11.

16 is a diagram for explaining the connection between the first voice coil bobbin and the second voice coil bobbin in FIG.

[Explanation of symbols]

 101 main frame 102 diaphragm 114,115 magnetic circuit 150 subframe

Claims (5)

[Claims] 1. A speaker in which a plurality of voice coils are attached to a common diaphragm in which a plurality of cones are arranged in series and integrated, and an elongated main frame to which an outer peripheral portion of the diaphragm is attached, and the main frame. A subframe made of a material having a coefficient of linear expansion smaller than that of the material of the main frame, and a plurality of magnetic circuits mounted on the subframe and driving the plurality of voice coils. Speaker. 2. The speaker according to claim 1, wherein the main frame is made of resin and the sub frame is made of metal. 3. The speaker according to claim 2, wherein the magnetic circuit and the sub-frame are attached by caulking. 4. A hole is formed in a side surface on the long width side of the main frame, and an extension portion extending to a vicinity of an opening on the outer wall side of the hole of the main frame is provided in the subframe, and an inner peripheral portion is provided. 4. The speaker according to claim 1, wherein an outer peripheral portion of a damper attached to the diaphragm is attached to an extending portion of the subframe. 5. A speaker in which a plurality of voice coils are mounted on a common diaphragm in which a plurality of cones are arranged in series and integrated into one another, wherein a plurality of magnetic circuits for driving each voice coil are magnetized in adjacent magnetic circuits. A speaker characterized in that the direction is reversed.