JPH11355886A - Speaker device - Google Patents

Abstract

(57) Abstract: A simple reaction is applied to a yoke and a plate of one loudspeaker to offset or attenuate a reaction force due to a motive force when the loudspeaker is driven by a diaphragm. An air passage is formed between a yoke (6) and a plate (5) of a speaker (3) and a shield case (25), and a space (20a) in a voice coil bobbin (11) below a cap (22) of the speaker (3) and a space between a damper (17) and the plate (5). Part 20c
The reaction force of the diaphragm 10 of the speaker 3 is canceled or attenuated by allowing air to flow in and out according to the driving of the speaker 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and lightweight speaker device, and more particularly to a speaker device capable of canceling a reaction force of sound radiation of a speaker device by using one speaker.

[0002]

2. Description of the Related Art Conventionally, as an effective means for extending the low-frequency reproduction limit of a speaker device, for example, 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 adjusted. A bass reflex type (phase inversion type) speaker device which inverts and radiates to the outside through an opening through a duct to enhance the sound wave emitted from the diaphragm of the speaker to the front so as not to distort the bass range is well known. Have been.

[0003] Such a phase inversion type speaker device is shown in FIG.
As shown in FIG. 1A, a speaker 3 is fixed to a speaker sound emission hole 2a formed in a baffle plate 2 provided on the front surface of a speaker box 1.

As shown in FIG. 6A, for example, a speaker 3 is provided with a ring-shaped magnet 4, a plate 5 having a center hole, and a yoke 6 attached so as to sandwich the ring-shaped magnet 4. A magnetic gap 7 is formed between the inner diameter side of the plate 5 and the outer diameter of the center pole 6a.
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 frame 8, and the outer peripheral portion of the cone-shaped diaphragm 10 is held by the edge 9 with arrow paper or the like.

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 has an inner diameter of the plate 5 and a center pole of the yoke 6. 6
It is designed to be inserted into a magnetic gap 7 formed by the outer diameter of a. 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.

Also, a duct 18 having an opening 18a is provided on the same surface as the speaker sound emission hole 2a of the baffle plate 2, and the phase of the sound emitted from the back surface of the diaphragm 10 of the speaker 3 is inverted.
Radiation is emitted from the opening 18 a of the duct 18 to the outside of the speaker box 1, and the low-frequency range of the sound emitted from the front surface of the diaphragm 10 is widened.

As described above, an electrical equivalent circuit of the phase inversion type speaker device can be represented as shown in FIG.

6A and 6B, S ₀ is the stiffness of the support system of the speaker 3, M ₀ is the equivalent mass of the support system of the speaker 3, R _ms0 is the mechanical resistance of the speaker support system,
_m0 is the mechanical resistance of the air loading of the speaker, R ₀ is expressed by R _m0 + R _ms0 = R ₀ equivalent mechanical resistance of the speaker. S _C is the stiffness in the speaker box 1, R _D is the mechanical resistance of the air load in the duct 18, and M _D is the air mass in the duct 18.

[0010] With above phase inversion type speaker apparatus as in, to be able to lower the bass reproduction limit compared to sealed, about 80% of the bass resonance frequency f ₀ of the speaker 3
It is said that the low-frequency reproduction range can be extended to a degree.

In such a loudspeaker device, the sound radiation force F ₁ due to the vibration of the diaphragm 10 of the loudspeaker 3 is equal to the acceleration α ₀ acting on the loudspeaker diaphragm 10 on the equivalent mass M ₀ of the loudspeaker 3 in FIG. F ₁ = M ₀ · α ₀ 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 acts as a force to return the diaphragm 10 to its original position. There was a problem that was hindered.

In order to solve such a problem, the present applicant has previously proposed a speaker device as shown in FIG. 7. In FIG. 7, portions corresponding to those in FIG. 6 are denoted by the same reference numerals.

In FIG. 7, a speaker box 1 is formed of a synthetic resin into a box shape integrally with a baffle plate 2. The speaker 3 having the same configuration as that described in detail in FIG. 6A is fixed to the speaker sound emitting hole 2a formed on the upper side of the baffle plate 2. First duct 1 arranged below baffle plate 2
8 and the opening 18a are integrally formed when the baffle plate 2 is formed.

Further, 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, and the second speaker 3b, preferably, the speaker 3 and the back surface are connected. Is fixed to the rear plate 1B so that the first
Second duct 18b having a larger duct diameter than the second duct 18
Are overlapped within a predetermined length of the first duct 18 and are planted integrally with the rear plate 1B so as to form a concentric cross section, and the first through the opening 18c of the second duct 18b.
Equivalent mass M of air radiating to the opening 18a of the duct 18
_D and the equivalent resistance _RD are configured to be large.

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.

According to the speaker device shown in FIG.
Radiation force F _D1 between the first and second ducts 18 and 18b
And reaction force -F _D1 and -F _D2 of F _D2 so are respectively offset, the radiation power of the first and second speakers 3 and 3b F ₁
And reaction force -F ₁ and -F ₂ of F ₂ is F ₁ ≒ F ₂ Tosureba can cancel each other.

[0017]

[SUMMARY OF THE INVENTION] However, in the speaker box 1 in order to as in the above-mentioned structure does not swing supporting reaction forces -F ₁ by acting force F ₁ of the speaker 3 small and lightweight speaker box 1 In addition, there is a problem that a pair of speakers 3 and 3b having substantially the same structure is required, which is not only a bottleneck for miniaturization but also expensive.

Further, in the conventional small speaker, the magnet of the magnetic circuit for driving the diaphragm is very small, and the voice coil is wound around a small-diameter voice coil bobbin to increase the sound pressure of the speakers 3 and 3b. , The resonance sharpness (hereinafter referred to as Q ₀ ) of the lowest resonance frequency (hereinafter referred to as f ₀ ) was inevitably increased.

[0019] In addition, of the large small speaker of such a Q ₀ in Q ₀ is the low frequency range for further increases in the f ₀ can not play the expansion of the low-pass If you have disposed in the speaker box of small volume There was a problem that the sound quality was significantly deteriorated.

In general, a very small speaker often uses a fixed edge, which simultaneously forms an edge when the diaphragm is made, but the fixed edge of such a small speaker is hard and the voice coil is lightweight, so that the speaker is light. There is a problem that it is also difficult to lower f ₀ of.

Further, the vibration system of the speaker was made equal.
One of Q ₀ is higher f ₀ is the speaker had adverse effects become unsuitable for reproduction of low frequency increases in proportion to f _0.

An object of the present invention is to provide a speaker device which solves the above-mentioned problems, and a problem to be solved by the present invention is to provide a small and lightweight speaker box by performing simple processing on one speaker unit. To offset or attenuate the reaction force of the radiating force of the loudspeaker, to prevent rocking of the loudspeaker device, to radiate a strong low frequency band, to reduce Q ₀ , and to set f ₀ of the loudspeaker to the low frequency side. To perform low-frequency expansion and good-quality low-frequency radiation.

[0023]

A speaker device according to the present invention is a speaker device in which a speaker comprising a vibration system and a magnetic circuit is built in a speaker box, wherein a voice coil inner diameter and a cap are inserted through a magnetic gap constituting a magnetic circuit. An air passage that flows into and out of a second space surrounded by a first space and / or a damper that forms a vibration system and a plate that forms a magnetic circuit is provided when the speaker is driven. The reaction force against the sound radiation force of the diaphragm is the first
And attenuated or attenuated by the air flowing into and out of the second space.

According to the loudspeaker apparatus of the present invention, by simply performing a simple processing on one loudspeaker, the reaction force due to the radiating force of the loudspeaker built in the small and lightweight loudspeaker box is canceled to prevent oscillation and to reduce the low frequency. As the frequency increases, the speaker Q ₀ can be lowered and f ₀ can be expanded to a lower frequency side by the equivalent mass of air passing through a slit or a magnetic gap formed in the yoke of the magnetic circuit.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A small speaker according to the present invention will be described below in detail with reference to FIGS. In the present invention, parts corresponding to the speakers shown in FIGS. 6 and 7 are denoted by the same reference numerals.

FIG. 1 is a side sectional view of the speaker device of this embodiment, FIG. 2 is a side sectional view of a speaker used for the speaker device of the present invention, and FIGS. 3A and 3B are used for the speaker of the present invention. 4A and FIG. 4 are perspective views of a yoke and a plate.
(B) is a perspective view and a plan view of another yoke used for the speaker of the present invention, and FIG. 5 is a side sectional view of another speaker device of the present invention.

The speaker 3 incorporated in the speaker box of the speaker device in FIG. 1 will be described first with reference to FIGS. In FIG. 2, reference numeral 3 denotes a small speaker as a whole according to the present embodiment, and a yoke 6 has a disk-shaped portion made of a plate material such as pure iron and a column-shaped portion provided upright at the center of the disk-shaped portion. A center pole 6a and a magnet guide portion 6b formed of a step formed concentrically with the center pole 6a in a disk-like portion are integrally formed in an inverted T-shaped cross section.

FIG. 3A is a perspective view showing an example of the configuration of the yoke 6 used in this embodiment. Although the magnet guide portion 6b is not shown in the yoke 6 in FIG.
A slit 6c is formed in the upper surface of the yoke 6 in the radial direction within an angle range of, for example, 120 ° from the center of the center pole 6a to form an air passage, and a resistance material 6d is provided in the slit 6c as necessary. It may be configured to adjust the amount of air that is inserted and passes through the slit 6c. FIG.
Reference numeral 25 indicates a shielding case, which will be described later in FIG.

The ring-shaped magnet 4 magnetized in the thickness direction of ferrite or the like is adhered on the disc-shaped portion of the yoke 6 via an adhesive. The inner diameter of the ring-shaped magnet 4 is fitted and positioned in a step portion of a magnet guide portion 6b formed in a disk-shaped portion of the yoke 6.

The plate 5 is joined to the magnet 4. In this case, the gap guide is left inserted in the center pole 6a, and an adhesive is applied to the upper surface of the magnet 4, and the inner diameter of the plate 5 is inserted into the outer diameter of the gap guide and fixed. The plate 5 is made of a plate made of pure iron or the like and has a through hole 5b formed at the center thereof. The voice coil 12 is formed in a magnetic gap 7 formed between the inner circumference of the through hole 5b and the outer diameter of the center pole 6a. Is arranged. As shown in FIG. 3B, a slit 5a is formed in the outer periphery of the plate 5 as needed, for example, in an angle range of 120 ° from the center of the plate 5 so as to be in contact with the inner periphery of the shielding case 25. Air passage when mounting.

A metal part of the magnetic circuit is formed by fixing a funnel-shaped frame 8 made of steel or the like to the plate 5. Below the magnetic air gap 7, the outer circumference of the center pole 6 a and the inner diameter of the magnet 4 are defined. An enclosed second space 20b is formed.

A voice coil 12 wound around a cylindrical voice coil bobbin 11 is provided in the magnetic space 7 of the magnetic circuit.
Is inserted, and the voice coil bobbin 11 is held via an airtight damper 17 having a corrugation of a waveform so as to be able to swing up and down.

In order to obtain an airtight damper 17, two or three thin cloths are stacked and joined to form a damper, or a damper 17 having a surface coated with a synthetic resin solution or the like is used. .

The inner diameter of the damper 17 is joined to the upper end of the voice coil bobbin 11 via an adhesive, and the outer diameter is joined to the outer periphery of the bottom surface of the frame 8. Further, the inner diameter of the funnel-shaped diaphragm 10 having a free or fixed edge 9 made of paper or the like is attached to the voice coil bobbin 1.
1, and the largest diameter portion of the diaphragm 10 is fixed to the peripheral edge of the upper opening of the frame 8 via a gasket 19.

At the upper end of the voice coil bobbin 11 or the inclined portion of the diaphragm 10, a cap 22 made of a highly air-tight material such as aluminum is provided in a dome shape with an adhesive so as to air-tightly cover the upper end of the voice coil bobbin 11. To join.

The tinsel wire 16 is connected to the voice coil 12 and supplies an audio signal to the voice coil 12 via an input terminal 15 attached to the frame 8.

By assembling the small speaker as described above, the first space 20a surrounded by the inner diameter of the cap 22 and the voice coil bobbin 11 and the second space 20b
And the third between the airtight damper 17 and the upper surface of the plate 5.
Is formed.

The ring-shaped cancel magnet 26 joined to the lower side of the yoke 6 is magnetized so that the same polarity is opposed to the magnet 4, and the cylindrical portion of the cup-shaped shield case 25 is formed. The inner diameter and the outer periphery of the plate 5 are joined so that they have the same polarity.

A speaker device in the case where the speaker 3 having the structure described in FIGS. 2 and 3 is disposed in the speaker box 1 having the phase inversion type ducts 18a and 18b having the same structure as that described in detail in FIG. A side sectional view is shown in FIG.

The speaker 3 shown in FIG. 2 may be arranged to face the speaker sound emission hole 2a formed in the baffle plate 2 as shown in FIG. 1, but the speaker 3 shown in FIG. Since these are slightly changed, these points will be described with reference to a perspective view and a plan view of the yoke in FIG.

FIG. 4A is a perspective view of the yoke 6 as viewed from the bottom side, and the bottom surface of the yoke 6 has n equal angles around the center point 0 of the center pole 6a (in FIG. 4, each angle is 120 °). Slits 6c, 6 in the direction from the outer circumference toward the center point 0
The slits 6c, 6c, 6c are extended to the vicinity of the outer periphery of the center pole 6a beyond the position of the magnet guide 6b, and contact with the end positions of the slits 6c, 6c, 6c from the bottom surface of the yoke 6. Through hole 6 toward the upper surface
e, 6e, and 6e are formed to form an air passage, and the openings at the lower ends (upper ends in FIG. 4A) of the slits 6c, 6c, 6c are covered with the cancel magnet 26 to form a second air passage. Have been.

On the other hand, in the speaker 3 of FIG. 2, a slit 5a is formed on the outer periphery of the plate 5 as shown in FIG. 3B in order to form a first air passage.
As shown in the plan view of the plate 5 in FIG. 4B, the circumference generated due to a fitting difference at the time of machining between the outer circumference 5c of the plate 5 and the inner circumference 25a of the shield case 25 formed in a cup shape. The gap 27 having the shape of a circle is used as a first air passage.

The speaker box 1 in FIG.
When the speaker 3 is small and lightweight with a volume of about 1 to 2 liters and the diameter of the speaker 3 is 7 cmφ or less, an acoustic signal is supplied from the terminal 13a to the voice coil 12 to make the speaker 3 When the diaphragm 3 is driven, the driving force F _{1 in the} F ₁ direction is F ₁ = M ₀ · α ₀ and the reaction force −F
₁ = M ₀ · α ₀ works.

On the other hand, with respect to the sound radiation force F ₁ of the diaphragm 10, the air in the first to third spaces 20 a, 20 b, 20 c expands, and the inner circumference 25 a of the shielding case 25 and the plate 5 A circumferential gap 27 between the outer peripheries or, in the case of the speaker 3 of FIG.
a, 5a (see FIG. 3 (B)), air in the speaker box 1 flows between the outer periphery of the magnet 4 and the inner periphery of the shield case 25 as shown by an arrow 28 → slit 6c → through holes 6c, 6c in FIG. , 6c → the ring-shaped second space 20b between the inner circumference of the magnet 4 and the outer circumference of the center pole 6a →
The space of the magnetic gap 7 between the inner diameter of the through hole 5b of the plate 5 and the outer diameter of the voice coil 12 → the airtight damper 17 and the plate 5
Between the third space 20c and the second space 20b.
→ The space of the magnetic gap 7 between the outer periphery of the center pole 6a and the inner diameter of the voice coil bobbin 11 → Air flows in the path of the first space 20a.

The sound cancellation or like attenuating effect a reaction force -F ₁ to radiant force F ₁ forces the air diaphragm 10 that flows in this manner in the first and third space portions 20a and 20c F
_Dn = M _Dn · α _Dn (where M _Dn is the equivalent mass of air in each air passage, α _Dn is the acceleration of air in each air passage)
And reaction force -F _Dn action force at the gap 27 or the slits 5a is a first air passage above and reaction force (F _D1, -F _D1) and second slits 6c of the yoke 6 is an air passage Force and reaction force at (F _D2 , -F _D2 )
And the acting force and reaction force (F
_D3, -F _D3) a _{F Dn = F D1 + F D2} -F D3 -F Dn = -F D1 + (- F D2) + (- F D3) and ask F ₁ ≒ F _Dn become as balanced if For example, using one speaker 3-
The reaction forces F ₁ is capable canceled or attenuated by the action force F _Dn of the air passage portion is obtained.

The case where the diaphragm 10 is driven in the F direction has been described above. However, when the diaphragm 10 is driven in the -F ₁ direction, the air between the first to third space portions 20a, 20b, and 20c is compressed. It flows out into the speaker box 1 through the air path opposite to that described above, and operates in a transportable manner.

Therefore, if the balance is made so that F ₁ ≒ F _Dn , the reaction force −F ₁ of the sound radiation force F ₁ of the loudspeaker 3 can be applied to the yoke 6 and the plate 5 only by performing simple processing on the yoke 6 and the plate 5. A loudspeaker device that can be canceled or attenuated by the force F _Dn is obtained.

Also, in the case of FIG. 1, the first duct 18a and the second duct 18b are used to apply a second radiation force F _D4 (or −F _D4 ) to the duct 18 at the opening 18a of the first duct 18. Duct radiation force F _D5 at opening 18c of duct 18b ( _or-
Since F _D5 ) is set to F _D4 ≒ F _D5 , they are mutually offset and supported, so that the condition for not swinging the speaker box 1 is to satisfy the above-mentioned F ₁ ≒ F _Dn. Become.

Further, it is well known that the low-frequency characteristic of the vibration system of the speaker 3 is generally determined by Q _{0 at} f ₀ .

Now, let the effective mass of the speaker vibration system be M ₀ ,
The stiffness of the vibration supporting portion is S ₀ , the internal resistance of the output amplifier is R ₀ , the resistance of the voice coil is Rv, the length of the voice coil is Lv (cm), the mechanical resistance of the vibration system is Rm, and the internal volume of the speaker box is Assuming that the stiffness is Sc, the resistance in the speaker box is Ra, and the magnetic flux is Bg, Q ₀ can be expressed by the following equation (1).

As is apparent from the above equation (1), when the diaphragm 10 is driven, the magnetic gap 7, the plurality of slits provided in the yoke 6 and the plate 5, and the gap 27 provided between the yoke 25 and the plate 5. Etc., the air resistance Rm of the air passing therethrough increases, the denominator of the equation (1) increases, and Q
Obviously it works to reduce the value of ₀ .

Accordingly, the transition of f _{0 to} the high frequency side can be prevented with the decrease of Q ₀ , the low frequency range is expanded, and a speaker device capable of radiating high quality low frequency can be obtained.

In the above-described configuration, the speaker device in which the speaker 3 using the cancel magnet is disposed in the speaker box 1 has been described. However, as shown in FIG. 5, the speaker 3 having the same configuration as that described in FIGS. The third damper 17 and the cap 22 are kept airtight, and the third space 20 c
For example, one end of an L-shaped duct 30 is fixed to the frame 8 as shown in FIG.
Insert and the fixed and the other end to the damper 17 to one end hermetically By forming so as to extend into the speaker box 1, to F ₁ direction of the sound radiation force of the speaker 3, one opening of the duct 30 speaker acting force of the air suction or expelling duct 30 in a box with F _Dn and -F _Dn, for example, the manner to cancel or attenuate -F ₁ direction of the reaction force against the acting force F ₁ of the speaker 3 to You may.

[0054]

According to the speaker device of the present invention, a single speaker is used, and a slit is provided between the plate and the shield case or the yoke to form an air passage. A speaker device capable of canceling or attenuating a reaction force against a sound radiation force and expanding a low range and emitting sound without swinging a small and lightweight speaker box can be obtained. Furthermore, the transition value of at resonance sharpness Q ₀ to the lowest resonance frequency f _0, according to the speaker of the present invention can be reduced only by providing an air passage, the low band resonance frequency f ₀ to the low frequency side It becomes possible. Further, a speaker device capable of attenuating the reaction force of the speaker by simply arranging one of the above speakers in the speaker box is obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a speaker device of the present invention.

FIG. 2 is a side sectional view of the speaker of the present invention.

FIG. 3 is a perspective view of a yoke and a plate used for the speaker of the present invention.

FIG. 4 is a perspective view of another yoke used for the speaker of the present invention and a plan view of a plate.

FIG. 5 is a side sectional view of another speaker device of the present invention.

FIG. 6 is a cross-sectional view of a conventional speaker device and an electrical equivalent circuit diagram thereof.

FIG. 7 is another side sectional view showing the configuration of a conventional speaker device.

[Explanation of symbols]

1 speaker box, 3, 3b speaker, 5
a, 6c slit, 10 diaphragm, 17 damper, 18, 18b, 30 duct, 27 gap

Claims (3)

[Claims] 1. A speaker device in which a speaker comprising a vibration system and a magnetic circuit is incorporated in a speaker box, wherein a first space portion surrounded by a voice coil inner diameter and a cap through a magnetic gap constituting the magnetic circuit. And / or providing an air passage that flows into and out of a second space surrounded by a damper that forms the vibration system and a plate that forms the magnetic circuit, so that the sound radiation force of the diaphragm generated when the speaker is driven is provided. The speaker device is characterized in that the reaction force against the air is offset or attenuated by the air flowing into and out of the first and second spaces. 2. A first air inflow / outflow passage provided in a yoke constituting the magnetic circuit and a second air provided between a plate and a cover for allowing air to flow into the first and second spaces. 2. An inflow / outflow passage having an inflow / outflow passage.
The speaker device according to any one of the preceding claims. 3. A third air inflow / outflow passage is provided in a damper constituting the vibration system so that air flows into the second space. Speaker device.