JP2000041292A - Speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small sized light weight speaker system where a low pitch sound is reproduced excellently. SOLUTION: The speaker system is provided with a speaker 3 mounted on a baffle plate in front of a speaker box 1, an air-tight chamber 21 that is placed at a position corresponding to the speaker 3 on a rear side in the inside of the speaker box 1, a vibrating body 23 arranged via a moving body 22 which is placed on the speaker side of the air-tight chamber 21 and generates a reaction in opposite direction to the sound emission direction by using the reaction opposite to the sound emission direction of the speaker 3 as a drive force, and an air-tight space 20 formed to the speaker 3, and the air-tight chamber 21 and the air-tight space 20 are connected by a soft pipe 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a small and lightweight speaker device.

[0002]

2. Description of the Related Art Generally, as an effective means for extending a low-frequency reproduction limit of a small and lightweight speaker device, an opening and a duct are provided in a baffle plate provided with a speaker, and a phase of a sound emitted from a back surface of a diaphragm of the speaker is provided. A bass reflex type (phase inversion type) speaker device in which the sound is emitted from the diaphragm of the speaker to the front by inverting the sound through the duct to the outside through the duct to prevent distortion of the bass range is good. Are known.

In such a phase inversion type speaker device, a speaker 3 is fixed opposite a speaker sound emission hole 2a formed in a baffle plate 2 provided on a front surface of a speaker box 1 as shown in FIG.

As shown in FIG. 7, for example, a speaker 3 includes a ring-shaped magnet 4, a plate 5 and a yoke 6 mounted so as to sandwich the ring-shaped magnet 4.
And a magnetic gap 7 is formed between the inner peripheral side of the plate 5 and the center pole 6 a of the yoke 6. A frame 8 of the speaker 3 is attached to the plate 5, and an edge 9 is provided on an outer peripheral portion of the diaphragm 10. The outer peripheral portion of the cone-shaped diaphragm 10 is held by the frame 8 by the edge 9.

On the other hand, a voice coil bobbin 11 is mounted on the inner peripheral portion of the diaphragm 10, and a voice coil 12 is wound around the voice coil bobbin 11, and the voice coil 12 is mounted on the center pole 6a of the plate 5 and the yoke 6. Is inserted into the magnetic gap 7 formed by the above. Reference numeral 17 denotes a damper for holding the voice coil 12 in the magnetic gap 7.

An acoustic signal from an input terminal 13a provided at a predetermined position outside the speaker box 1 is connected to a connection line 1
4a to the terminal 15 of the speaker 3 via the terminal 15a.
Of the voice coil 12 via the tinsel wire 16
To supply.

[0007] Further, the speaker sound emission hole 2a of the baffle plate 2
A duct 18 having an opening 18a is provided on the same surface as the above, and the phase of the sound emitted from the back surface of the diaphragm 10 of the speaker 3 is inverted and radiated from the duct 18 to the outside of the speaker box 1. The bass range of the sound coming out from the front is expanded.

As described above, by using a phase inversion type speaker device, the bass reproduction limit can be lowered as compared with the sealed type, and about 80% of the bass resonance frequency f ₀ of the speaker 3 can be obtained.
It is said that the low-frequency reproduction range can be extended to a degree.

In such a speaker device, the sound radiation force F ₁ due to the vibration of the diaphragm 10 of the speaker 3 is obtained by multiplying the effective mass M ₁ of the speaker 3 by the acceleration α _{1 at} which the diaphragm 10 moves, that is, F ₁ = It can be expressed as M ₁ α ₁ . To such sound radiation force F _1, the reaction force -F ₁ toward the speaker box 1 from the rear side of the diaphragm 10 also becomes remarkable the smaller the volume of the speaker box 1 speaker device is small and light, The air in the speaker box 1 is repeatedly compressed and expanded by the vibration of the diaphragm 10, and this air is
As a result, the speaker box 1 is swung, and there is a problem that bass reproduction is hindered.

In order to solve such a problem, the present applicant has previously proposed a speaker device as shown in FIG. 8. In FIG. 8, parts corresponding to those in FIG. Description is omitted.

In FIG. 8, a speaker box 1 is formed of a synthetic resin into a box shape integrally with a baffle plate 2. A speaker 3 having the same configuration as that described in detail with reference to FIG. 7 is fixed to the speaker sound emission hole 2a formed on the upper side of the baffle plate 2. The first duct 18 and the opening 18a disposed below the baffle plate 2 are integrally formed when the baffle plate 2 is formed.

A speaker sound emission hole 2b is formed at a position opposite to the speaker sound emission hole 2a formed on the baffle plate 2 above the rear face plate 1B, so that the second speaker 3b, preferably the speaker 3 and the back surface, are connected to each other. Are fixed to the rear panel 1B so as to face the speaker sound emission hole 2b, and the second duct 18b having a larger duct diameter than the first duct 18 overlaps within a predetermined length of the first duct 18. And planted integrally with the rear plate 1B so that a concentric cross section is formed,
And it is configured so as to increase the equivalent mass M _D and the equivalent resistance R _D of the air emitted through the opening 18c of the second duct 18b in the opening 18a of the first duct 18.

Further, the first and second speakers 3 and 3b
Are supplied with the same input acoustic signal via input terminals 13a and 13b and connection lines 14a and 14b disposed on the rear panel 1B.

[0014] reaction forces of the duct radiation force F _D1 and F _D2 between the first and second ducts 18 and 18b to form a so-called folded duct according to the speaker apparatus of Figure 8 described above -F
_D1 and -F _D2 is reactive force -F ₁ radiation force F ₁ and F ₂ of the first and second speakers 3 and 3b so are respectively offset
And -F ₂ the F ₁ ≒ F ₂ Tosureba can each other to cancel.

[0015]

However, the above-described structure requires a pair of speakers 3 and 3b having substantially the same structure in the speaker box 1, which makes it difficult to reduce the size of the speaker box 1 and increases the cost. was there.

Further, the vibration system of the speaker was made equal.
In one speaker, the higher the low-pitched resonance frequency f ₀ , the larger the resonance sharpness Q of the diaphragm becomes in proportion to f ₀ , so that there is a problem that it is not suitable for low-frequency reproduction.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small and lightweight speaker device which can prevent swinging of a small and lightweight speaker box and can reproduce good bass sound.

[0018]

A speaker device according to the present invention comprises a speaker mounted on a baffle plate on a front surface of a speaker box, an airtight chamber provided at a position corresponding to the speaker on a rear surface inside the speaker box, and A vibrating body disposed on the speaker side of the airtight chamber and provided via a movable body that generates an acting force in a direction opposite to the sound radiation direction using a reaction force in a direction opposite to the sound radiation direction of the speaker as a driving force. And an airtight space formed in the speaker, and the airtight chamber and the airtight space are connected by a soft pipe.

According to the present invention, the vibrating body generates the acting force in the direction opposite to the sound radiation direction by using the reaction force in the direction opposite to the sound radiation direction of the speaker as the driving force, and is connected by the soft pipe. The volume change between the airtight space of the speaker and the airtight chamber is opposite to each other, and the vibrator in the airtight room moves in the direction opposite to the direction of sound emission of the speaker due to the change in volume, and generates a force. The radiation force can be offset by the acting force and the moving force of the vibrating body, and the vibration of the speaker box due to the radiation of the sound can be eliminated, so that good bass reproduction can be performed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a speaker device according to the present invention will be described below with reference to FIG. In FIG. 1, portions corresponding to FIG. 7 are denoted by the same reference numerals.

FIG. 1 shows a side cross section of the speaker device of the present embodiment. In the example of FIG. 1, a configuration of a phase inversion type speaker device using a so-called folded duct is used. In the speaker device of the example shown in FIG.
The speaker 3 is formed in a substantially rectangular parallelepiped shape with S resin or the like, and the speaker 3 is fixed to a speaker sound emission hole 2a formed in a baffle plate 2 provided on the front surface of the speaker box 1.

The speaker 3 is, for example, as shown in FIG.
A ring-shaped magnet 4, a plate 5 attached to sandwich the ring-shaped magnet 4, a yoke 6 having a center pole 6a and a flange 6b are provided, and an inner peripheral side of the plate 5 and a center pole 6a of the yoke 6 are provided. The frame 5 of the speaker 3 is attached to the plate 5, and an edge 9 is provided on the outer periphery of the diaphragm 10, and the edge 9 forms an outer periphery of the cone-shaped diaphragm 10. The part is held by the frame 8.

On the other hand, a voice coil bobbin 11 is mounted on the inner peripheral portion of the diaphragm 10, and a voice coil 12 is wound around the voice coil bobbin 11. The voice coil 12 is mounted on the center pole 6 a of the plate 5 and the yoke 6. Is inserted into the magnetic gap 7 formed by the above. A damper 17a holds the voice coil 12 in the magnetic gap 7.

In the example shown in FIG.
a is, for example, an airtight damper obtained by impregnating a cloth with a synthetic resin, and the cap 19 for preventing dust intrusion is also airtight;
The flange 6b of the yoke 6 of this speaker, the ring-shaped magnet 4, the airtight damper 17a, the voice coil bobbin 1
The space surrounded by 1 and the cap 19 is referred to as an airtight space 20.

An acoustic signal from an input terminal 13a provided at a predetermined position outside the speaker box 1 is supplied to a terminal 15 of the speaker 3 via a connection line 14a.
5 from the voice coil 1 through the tinsel wire 16.
2.

The speaker sound emission hole 2a of the baffle plate 2
A first duct 18 having an opening 18a on the same surface as the first duct 18, and a second duct 18b having a larger diameter than the first duct 18 is overlapped within a predetermined length of the first duct 18, and It is planted integrally with the rear plate 1B so that a concentric cross section is formed, and the sound from the back of the speaker 3 is inverted in phase from the opening 18a of the first duct 18 through the opening 18c of the second duct 18b. Radiated out of the speaker box 1 to expand the bass range of the sound from the front of the diaphragm 10.

In this embodiment, a cylindrical side wall 21a protruding inward is provided at a position facing the speaker 3 on the rear face plate 1B of the speaker box 1, and an outer peripheral portion is formed so as to close the opening of the cylindrical side wall 21a. And a disk-shaped vibrating body 23 is disposed at the center thereof, and a disk-shaped airtight chamber 21 is provided.

In this embodiment, a predetermined portion of the side wall 21a of the airtight chamber 21 and a through hole provided in a predetermined portion of the flange 6b of the yoke 6 of the airtight space 20 of the speaker 3 are formed by using a soft pipe such as a vinyl tube 24. So that they are connected via

In this case, the effective mass of the vibration system of the speaker 3 is M ₁ , and the acceleration at which the diaphragm 10 of the speaker 3 moves is α
₁ a sound radiation force F ₁ when the is represented as F ₁ = M ₁ alpha _1, the vibrating body 23, the sound emission direction opposite to the direction of the reaction force -F sound radiation force F ₁ of the speaker 3 The acting force F _{S in the} direction opposite to the sound radiation direction generated with ₁ as the driving force is given by F _S = M _S , where M _S is the mass of the vibrating body 23 and α _S is the moving acceleration of the vibrating body 23. represented by alpha _S.

Further, the diaphragm 1 due to the sound radiation of the speaker 3
The amplitude of 0 X, when the effective area of the vibration plate 10 and the S, when driving the diaphragm 10 of the speaker 3 sound radiation force F _1, the volume of air S · X in the speaker box 1
And the pressure of the air decreases.

At this time, the volume of the airtight space 20 of the speaker 3 is also set such that the effective area of the cap 19 is S _C , and the airtight damper 17 is provided.
Assuming that the effective area of a is S _D , it changes by S _C × X + S _D × X / 2, the pressure of the hermetic space 20 fluctuates, and this pressure fluctuation is transmitted to the hermetic chamber 21 through the vinyl tube 24, At this time, the air moves until the pressure in the hermetic space 20 and the pressure in the hermetic chamber 21 become equal. At this time, the vibrating body 23 is located at the center of the damper 22. And moves in the opposite direction to the diaphragm 10. Here, S _S is the sum of the areas of the damper 22 and the vibrating body 23 of the airtight chamber 21.

Therefore, the magnitude of the pressure due to the change in the volume of the hermetic chamber 21 is as follows. Becomes Here P _S is still pressure, V _S of the airtight chamber 21 is the volume of the airtight chamber 21.

Further, since the diaphragm 10 moves and the volume of the speaker box 1 changes by SX, Force acts in the direction opposite to the direction of the acting force of the vibrating body 23, so that the total acting force F _T of the vibrating body 23 is Becomes Here, P _B is the static pressure in the speaker box 1 and V _B is the volume in the speaker box 1.

In the present embodiment, it is assumed that F ₁ ≦ _FT is satisfied.

When the stiffness of the damper 22 in the airtight chamber 21 is k _S , the resonance frequency f _S of the vibrating body 23 is In this example, the resonance frequency f _S is set to be lower than the bass resonance frequency f _O of the speaker 3.

In this case, the resonance sharpness Q becomes large, and the vibrating body 23 of the airtight chamber 21 acts in the direction opposite to the sound radiation direction using the reaction force −F ₁ of the sound radiation force F ₁ of the speaker 3 as the driving force. A force F _S = M _S α _S is generated.

[0037] In this example, since the F ₁ ≦ F _T,
Reaction of the combined action force F _T of the sound radiation force F ₁ of the reaction force -F ₁ sufficiently supported by the reaction force -F _T of the combined action force F _T of the vibrator 23, or the sound radiation force F ₁ to the vibrating body 23 Force-F _T
Can be added, the sound radiation power of the speaker 3 can be increased without loss, and good low-frequency sound reproduction can be performed even with a small and lightweight speaker device.

FIGS. 2 to 6 show other examples of the embodiment of the present invention. 2 to 6, the same reference numerals are given to portions corresponding to FIG. 1, and detailed description thereof will be omitted.

The example of FIG. 2 is different from the example of FIG. 1 in that a predetermined portion of the side wall 21a of the airtight chamber 21 and the center pole of the yoke 6 of the airtight space 20 of the speaker 3 are used to connect the airtight chamber 21 and the airtight space 20 of the speaker 3. The through hole 6a is connected via a soft pipe, for example, a vinyl tube 24, and the other parts are configured in the same manner as in FIG.

It can be easily understood that the same operation and effect as in FIG. 1 can be obtained in the example of FIG.

The example shown in FIG. 3 is different from the example shown in FIG. 1 in that a predetermined portion of the side wall 21a of the airtight chamber 21 and a predetermined portion of the airtight damper 17a of the airtight space 20 of the speaker 3 are connected. The side portions are connected to each other via a soft pipe such as a vinyl tube 24, and the other portions are configured in the same manner as in the example of FIG.

It can be easily understood that the same effects as those of the example of FIG. 1 can be obtained in the example of FIG.

FIG. 4 shows an example in which the damper 17 shown in FIG.
a is a damper 17 having air permeability and the frame 8
Is an airtight frame 8a, and the airtight frame 8a, the diaphragm 10, the ring-shaped magnet 4, and the flange 6b of the yoke 6 form an airtight space 20a of the speaker 3. Other configurations are the same as those in the example of FIG.

In the example of FIG. 4, since the frame 8a of the speaker 3 is airtight, the total acting force F
_T is Becomes

[0045] The relationship also combined action force F _T of the sound radiation force F ₁ Toko of the vibrating member 23 in the present embodiment and F ₁ ≦ F _T.

[0046] Since the F ₁ ≦ F _T In FIG. 4 example the reaction force -F ₁ sound radiation force F ₁ sufficiently supported by the reaction force -F _T of the combined action force F _T of the vibrator 23, or the sound reaction force -F comprehensive action force F _T of the vibrating body 23 in a radial force F ₁
A part of _T can be added, the radiation power of the sound of the speaker 3 can be increased without loss, and good bass reproduction can be performed even with a small and lightweight speaker device.

In the example shown in FIG. 4, the frame 8a on the rear surface of the speaker 3 is airtight. Area S _S and amplitude 2X
The volume change of the product of S / S _S is S _S · 2X · S / S _S = 2X · S.

Therefore, the hermetic frame 8a has a very large volume, and the bass resonance frequency f _O of the speaker 3 hardly increases, and the bass range can be easily expanded.

The example of FIG. 5 differs from the example of FIG. 4 in that the airtight chamber 21 and the airtight space 20a of the speaker 3 are connected to each other.
1 and the airtight space 20 of the speaker 3
4A is connected to a predetermined portion of the airtight frame 8a via a soft pipe, for example, a vinyl tube 24.
It has the same configuration as the example.

It can be easily understood that the same operation and effect as in FIG. 4 can be obtained also in the example of FIG.

FIG. 6 shows an example in which the movable body for holding the vibrating body 23 on the side wall 21a of the airtight chamber 21 is constituted by an edge 22a in the example of FIG. Others are configured similarly to the example of FIG.

It can be easily understood that the same operation and effect as in FIG. 5 can be obtained also in the example of FIG. FIG.
In the example, the outer periphery of the vibrating body 23 is
a, the amplitude is smaller than when the outer periphery of the vibrating body 23 is fixed to the side wall 21a via the airtight damper 22.

It should be noted that the present invention is not limited to the above-described example, but may adopt various other configurations without departing from the gist of the present invention.

[0054]

According to the present invention the reaction force -F ₁ sound radiation force F ₁ sufficiently supported by the reaction force -F _T of the combined action force F _T of the vibrator according to the present invention, or the vibration to the sound radiation force F ₁ some of the reaction force -F _T of the combined action force F _T of the body can be added to, without radiation force of the sound of the speaker is impaired, becomes stronger, even better a compact lightweight speaker device It has the benefit of bass reproduction.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of a speaker device of the present invention.

FIG. 2 is a sectional view showing another example of the embodiment of the present invention.

FIG. 3 is a sectional view showing another example of the embodiment of the present invention.

FIG. 4 is a sectional view showing another example of the embodiment of the present invention.

FIG. 5 is a sectional view showing another example of the embodiment of the present invention.

FIG. 6 is a sectional view showing another example of the embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an example of a conventional speaker device.

FIG. 8 is a cross-sectional view illustrating an example of a conventional speaker device.

[Explanation of symbols]

1 speaker box, 3 speaker, 4 ring magnet, 5 plate, 6 yoke, 6a
{Center pole, 6b} Flange, 8a {Airtight frame, 17a, 22} Airtight damper, 20} Airtight space, 21} Airtight room, 21a {Side wall, 22a}
Edge, 23 ° vibrator

Claims (4)

[Claims] 1. A speaker attached to a baffle plate on a front surface of a speaker box; an airtight room provided at a position corresponding to the speaker on a rear surface inside the speaker box; and a speaker room disposed on the speaker side of the airtight room. A vibrating body provided via a movable body that generates an acting force in a direction opposite to the sound radiation direction using a reaction force in a direction opposite to the sound radiation direction of the speaker as a driving force, and an airtight space formed in the speaker. Wherein the airtight chamber and the airtight space are connected by a soft pipe. 2. The speaker device according to claim 1, wherein the movable body is constituted by an edge, a damper, or the like. 3. The speaker device according to claim 1, wherein the airtight space is formed by making a damper of the speaker airtight. 4. The speaker device according to claim 1, wherein the hermetic space is formed by hermetically sealing a frame of the speaker.