close

Вход

Забыли?

вход по аккаунту

?

JPH11243593

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH11243593
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
compact and lightweight loudspeaker and a speaker apparatus, and more particularly to an
improvement of a compact loudspeaker and a loudspeaker apparatus in which the increase of the
lowest resonance frequency and the rise of resonance sharpness are small.
[0002]
2. Description of the Related Art Conventionally, as an effective means for extending the low
range reproduction limit of a speaker device, for example, an opening and a duct are provided in
a baffle plate provided with a speaker, and the phase of sound emitted from the back of the
diaphragm of the speaker is detected. It is well known that a bass reflex type (phase reversal
type) speaker device that inverts and radiates from the opening through the duct to intensify the
sound wave emitted to the front from the diaphragm of the speaker so as not to distort the bass
region. It is done.
[0003]
As shown in FIG. 3A, such a phase-reversal type speaker device fixes the speaker 3 so as to face
the speaker sound emission hole 2a formed in the baffle plate 2 provided on the front surface of
the speaker box 1.
[0004]
12-05-2019
1
For example, as shown in FIG. 3A, this speaker 3 is provided with a ring-shaped magnet 4 and a
plate 5 and a yoke 6 attached so as to sandwich the ring-shaped magnet 4. A magnetic air gap 7
is formed between the six center poles 6a.
Further, a frame 8 of the speaker 3 is attached to the plate 5, an edge 9 is provided on the outer
peripheral portion of the frame 8, and the outer peripheral portion of the cone-shaped
diaphragm 10 is held by the edge 9.
[0005]
On the other hand, a voice coil bobbin 11 is attached to the inner periphery of the diaphragm 10,
a voice coil 12 is wound around the voice coil bobbin 11, and the voice coil 12 is formed by the
plate 5 and the center pole 6a of the yoke 6. The magnetic gap 7 is inserted.
A damper 17 holds the voice coil 12 in the magnetic gap 7.
[0006]
Further, an acoustic signal from the input terminal 13a provided at a predetermined position
outside the speaker box 1 is supplied to the terminal 15 of the speaker 3 through the connection
line 14a, and an acoustic signal from the terminal 15 is voiced through the tinsel wire 16. The
coil 12 is supplied.
[0007]
In addition, a duct 18 having an opening 18a in the same plane as the speaker sound emission
hole 2a of the baffle plate 2 is provided, and the phase of the sound emitted from the back
surface of the diaphragm 10 of the speaker 3 is reversed. And radiate the sound out of the front
of the diaphragm 10 to a wide range.
[0008]
The electrical equivalent circuit in the phase inversion type speaker device as described above
can be represented as shown in FIG. 3 (B).
12-05-2019
2
[0009]
3A and 3B, S0 is the stiffness of the support system of the speaker 3, M0 is the equivalent mass
of the support system of the speaker 3, Rms0 is the mechanical resistance of the speaker support
system, and Rm0 is the air load of the speaker The mechanical resistance R0 is the equivalent
mechanical resistance of the speaker and can be expressed as Rm0 + Rms0 = R0.
SC is the stiffness in the speaker box 1, RD is the mechanical resistance of the air load of the duct
18 portion, and MD is the air mass of the duct 18 portion.
[0010]
As described above, by employing the phase-reversal type speaker device, the bass reproduction
limit can be lowered compared to the closed type, and the low-range reproduction range is
expanded to about 80% of the bass resonance frequency f0 of the speaker 3 It is supposed to be
possible.
[0011]
In such a speaker device, the sound radiation force F1 due to the vibration of the diaphragm 10
of the speaker 3 in FIG. 3A can be expressed by the acceleration α0 acting on the diaphragm 10
of the speaker 3 on the equivalent mass M0 of the speaker 3, that is, F1 = M0 α0 .
With respect to such a sound radiation force F1, the reaction force -F1 directed from the back
side of the diaphragm 10 toward the inside of the speaker box 1 is also remarkable when the
speaker apparatus is small and light and the volume of the speaker box 1 is small. The air in the
speaker box 1 repeats compression and expansion due to the vibration of 10, and this air acts as
a force to return the diaphragm 10 to the original position, thereby swinging the speaker box 1,
and the bass reproduction is inhibited. Had a problem.
[0012]
In order to solve such a problem, the present applicant has previously proposed a speaker
apparatus as shown in FIG. 4, and in FIG. 4, the corresponding parts to FIG.
12-05-2019
3
[0013]
In FIG. 4, the speaker box 1 is made of synthetic resin and molded integrally with the baffle plate
2 in a box shape.
The speaker 3 having the same configuration as that described in detail in FIG. 3A is fixed so as
to face the speaker sound emission hole 2 a formed on the upper side of the baffle plate 2.
The first duct 18 and the opening 18 a disposed on the lower side of the baffle plate 2 are
integrally molded when the baffle plate 2 is molded.
[0014]
In the upper part of the back plate 1B, a speaker sound emitting hole 2b is formed at a position
facing the speaker sound emitting hole 2a formed in the baffle plate 2, and the second speaker
3b, preferably the speaker 3 and the back face face each other. Similarly, the second duct 18b
fixed to the rear plate 1B to face the speaker sound emission hole 2b and having a larger duct
diameter than the first duct 18 is overlapped within a predetermined length of the first duct 18
And an integral mass of air which radiates to the opening 18a of the first duct 18 through the
opening 18c of the second duct 18b, and is integrally embedded with the rear face plate 1B so
that a concentric cross section is formed. It is configured to increase RD.
[0015]
Further, acoustic signals of the same input are supplied to the first and second speakers 3 and 3b
via the input terminals 13a and 13b disposed on the rear plate 1B and the connection lines 14a
and 14b.
[0016]
According to the speaker apparatus of FIG. 4 described above, the reaction force of the duct
radiation force FD1 and FD2 / 2 + FD2 / 2 between the first and second ducts 18 and 18b-FD1
and -FD2 / 2 + (-FD2 / 2) respectively Because of the cancellation, the reaction forces -F1 and -F2
of the radiation forces F1 and F2 of the first and second speakers 3 and 3b can be mutually
canceled if F1 .apprxeq.F2.
[0017]
12-05-2019
4
However, in the above configuration, a pair of speakers 3 and 3b having substantially the same
structure is required in the speaker box 1, so that it becomes difficult to miniaturize the speaker
box 1 and it becomes expensive. There was a problem.
[0018]
Furthermore, 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 the voice coil bobbin with a
small diameter to increase the sound pressure of the speaker. The resonance sharpness
(hereinafter referred to as Q0) of f0) is increased.
[0019]
In addition, when such a small speaker with large Q0 is disposed in the speaker box of a small
volume, reproduction expansion of the low range can not be performed, and Q0 at f0 becomes
even larger, so the sound quality in the low range is significantly deteriorated. There was a
problem.
[0020]
Generally, a very small speaker often uses a fixed edge that simultaneously produces an edge
when making a diaphragm, but the fixed edge of such a small speaker is hard and the voice coil is
also lightweight, so the speaker's f0 There was a problem that it was also difficult to lower.
[0021]
Furthermore, in the two loudspeakers in which the vibration system of the loudspeakers is made
equal, the higher the value of f0, the larger the Q becomes in proportion to f0.
[0022]
The present invention is intended to provide a speaker device that solves the problems of
overhead, and the problem to be solved by the present invention is to use a single speaker using
an inexpensive diaphragm such as a fixed edge to provide Q0. To make the speaker's f0
transition to the low band side, thereby expanding the low band and emitting a good low band
radiation, and to obtain a speaker apparatus capable of preventing the vibration of the
lightweight speaker box.
[0023]
SUMMARY OF THE INVENTION A speaker device according to the present invention uses an air-
12-05-2019
5
permeable damper, in which a diaphragm having an airtight cap is pierced with a plurality of
pores.
[0024]
According to the speaker apparatus of the present invention, the equivalent mass of air passing
through the plurality of through holes formed in the diaphragm can be used to lower the Q0 of
the speaker and to expand f0 to the low frequency side.
[0025]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The small speaker of the present
invention will be described in detail below with reference to FIGS. 1 and 2. FIG.
The parts corresponding to the speakers shown in FIGS. 3 and 4 are indicated by the same
reference numerals.
[0026]
FIG. 1 (A) is a plan view of the speaker device of this example, FIG. 1 (B) is a side sectional view, 3
shows the small speaker of this example as a whole, and the yoke 6 is a disc made of plate
material such as pure iron. , A cylindrical center pole 6a erected at the center position of the
discoid part, and a magnet guide part 6b consisting of a stepped part formed in the discoid part
concentrically with the center pole 6a. It is formed.
[0027]
A ring-shaped drive magnet 4 magnetized in the thickness direction of ferrite or the like is
adhered onto the disk-like portion of the yoke 6 described above via an adhesive.
The inner diameter of the ring-shaped drive magnet 4 is fitted to the step of the magnet guide
portion 6 b formed in the disk-like portion of the yoke 6 and positioned.
[0028]
12-05-2019
6
The plate 5 is joined to the driving magnet 4.
In this case, the gap guide is kept inserted into the center pole 6a, an adhesive is applied to the
upper surface of the driving 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 pure iron or the like in the form of a disk, and is a punched plate material
having a through hole at its center and is a voice coil in a magnetic gap 7 formed between the
inner peripheral edge of the through hole and the outer diameter of the center pole 6a. 12 are
provided.
[0029]
The metal part of the magnetic circuit is constituted by fixing the frame 8 formed in a funnel
shape with steel or the like to the plate 5, and the magnetic gap part 7 is surrounded by the outer
periphery of the center pole 6a and the inner diameter of the magnet 4 below the magnetic gap
7. A second space 20b is formed.
[0030]
The voice coil 12 wound around a cylindrical voice coil bobbin 11 is inserted into the magnetic
gap 7 of the magnetic circuit described above, and the voice is transmitted through the airpermeable damper 17 having a corrugated corrugation capable of vibrating in the vertical
direction. The coil bobbin 11 is held.
[0031]
The inner diameter portion of the damper 17 is bonded to the upper end of the voice coil bobbin
11 via an adhesive, and the outer diameter portion is bonded to the outer periphery of the
bottom surface portion of the frame 8.
Further, the inner diameter of a funnel-shaped diaphragm 10 with a free or fixed edge 9 made of
paper or the like is joined to the upper outer diameter of the voice coil bobbin 11 and the largest
diameter of the diaphragm 10 is the upper opening rim of the frame 8 The gasket 19 is fixed via
12-05-2019
7
the gasket 19.
[0032]
A cap 22 formed on the upper end of the voice coil bobbin 11 or the inclined portion of the
diaphragm 10 together with the bonding portion 23 made of a highly airtight material such as
aluminum in a dome shape such that the upper end of the voice coil bobbin 11 is airtightly
covered. It is joined via an adhesive.
[0033]
As shown in the plan view of FIG. 1A, in the diaphragm 10 of the present invention, a plurality of
thin through holes 21 are formed at appropriate positions of the inclined portion of the
diaphragm 10.
[0034]
Furthermore, the tinsel cord 16 is connected to the voice coil 12, and an audio signal is supplied
to the voice coil 12 through the input terminal 15 attached to the frame 8.
[0035]
As described above, by assembling a small speaker, the first space 20a between the diaphragm
10 and the upper surface of the plate 5 and the above-described second space 20b are formed.
[0036]
In general, it is well known that the low frequency characteristic of the vibration system of the
speaker 3 is determined by Q0 at f0.
[0037]
Now, the effective mass of the speaker's vibration system is M0, the stiffness of the vibration
supporting portion is S0, the internal resistance of the output amplifier is R0, the voice coil
resistance is Rv, the voice coil length is Lv (cm), the vibration system machine Assuming that the
resistance is Rm, the stiffness of the internal volume of the speaker box is Sc, the resistance in
the speaker box is Ra, and the magnetic flux is Bg, Q0 can be expressed by the following equation
(1).
[0038]
12-05-2019
8
As apparent from the above equation (1), when the diaphragm 10 is driven, the air resistance Rm
passing through the through holes 21 is increased through the plurality of through holes 21
formed in the diaphragm 10 (1 It is obvious that the denominator of the equation increases and
works to lower the value of Q0.
[0039]
Therefore, with the decrease of Q0, the transition of f0 to the high band side can be prevented,
the low band is expanded, and a speaker device capable of emitting a high-quality low band can
be obtained.
[0040]
FIG. 2 shows the case where the speaker 3 shown in FIG. 1 is disposed in the speaker box 1
having the phase inversion type duct 18, and the speaker box 1 has the same configuration as
that described in FIG. Is omitted.
[0041]
The above speaker box 1 is made of ABS resin or the like and is small and lightweight with a
volume of about 1 to 3 liters, and when considering the diameter of the speaker 3 having a
diameter of 8φ cm or less, an acoustic signal is transmitted from the terminal 13a to the voice
coil 12 When supplied and driving the speaker 3, the driving force F1 = M0 α0 and the reaction
force -F1 in the direction of the diaphragm F1 work.
[0042]
On the other hand, assuming that the number of the plurality of through holes 21 formed in the
inclined portion 10 of the diaphragm 10 is n, since the diaphragm 10 such as the fixed edge is
relatively thick in the respective through holes 21, The air that causes a duct effect and enters
the second space 20b from the back side of the diaphragm 10 through the first space 20a
generates a reaction force -FD / n against the action force FD / n.
[0043]
Therefore, countering the reaction forces -F1 and -F2 with the two speakers 3 and 3b as
described in Fig. 4 if counterbalanced such that FD / n + FD / n + ... = F1 like this The reaction
force of -F1 and the reaction force of-(FD / n + FD / n + ....) can be offset to some extent.
[0044]
12-05-2019
9
In this case, it is difficult to set F1 ≒ (FD / n + FD / n +...) Since F1> (FD / n + FD / n +...), But it is
clear that the offsetting effect can be expected to some extent.
[0045]
Further, when the radiation force at the opening 18a of the duct 18 when the phase inversion
duct 18 shown in FIG. 2 is provided is FD1 and the reaction force is -FD1, a conditional
expression for preventing the speaker box 1 from swinging. May be selected such that F1 + FD1
= (W + F1 + FD1) R.
In the above equation, W indicates the weight of the speaker device, and R indicates the frictional
resistance between the bottom of the speaker box 1 and the mounting portion.
[0046]
EXAMPLES Examples of measurement of f0 and Q0 and mechanical sharpness (QM) with and
without a plurality of through holes in the diaphragm 10 having a diameter of 6.5 .phi. Along
with
[0047]
First, as a comparative example, QM, Q0, and f0 when the speaker 3 of 6.5 .phi.cm is disposed in
a closed box (volume of 1000 liters) or a JIS box such as an infinite baffle plate are shown below.
(A) In the case of a speaker in which the through hole 21 is not formed QM = 4.88Q 0 = 2.79 f 0
= 170 Hz (b) through holes 21 having a diameter of 0.7 mm 12 from the center of the diaphragm
10 to the inclined portion at equal angles 12 In the case of a single speaker, QM = 4.74Q0 =
2.74f0 = 166Hz
[0048]
Next, QM, Q0 and f0 in the case where the same speaker 3 with a diameter of 6.5 .phi.cm as
described above is installed in a 1 liter speaker box are (H) Speaker QM with no through holes 21
= 7.3Q0 = 4. 2 f 0 = 245 Hz (D) In the case of a speaker in which twelve through holes 21 with a
12-05-2019
10
diameter of 0.7 mm are opened at the same angle from the center of the diaphragm 10 in the
inclined portion, QM = 5.15Q0 = 3.2f0 = 195 Hz.
[0049]
As apparent from the above measurement results, in the case of the present invention, the rise of
f0 can be shifted to the low band side of 195 Hz with respect to 245 Hz, and the resonance
acuity Q0 at the lowest resonance frequency f0 is also 4.2 Since the size can be lowered to 3.2, it
is possible to obtain a speaker and a speaker device capable of enhancing the low frequency
range and improving the sound quality of the low frequency range even with a small, inexpensive
speaker.
[0050]
In the above-described embodiment and example of the present invention, the number of the
through holes formed in the diaphragm 10 is twelve. However, if the number n is extremely
increased, the response of the midrange characteristic decreases, so less than 15 It is preferable
to reduce the number.
In addition, since the effect of the present invention can not be obtained if the number is
reduced, at least three or more through holes are required.
[0051]
Furthermore, the size of the through hole 21 is preferably 3 mm or less in diameter, and the
through hole position does not have to be drilled equiangularly in the range of 360 degrees from
the center of the diaphragm as shown in FIG. It is clear.
[0052]
According to the speaker of the present invention, the value of the resonance sharpness Q0 at
the lowest resonance frequency f0 can be reduced only by forming a thin through hole in the
diaphragm so that the low resonance frequency f0 can be reduced. It is possible to transition to
the side.
12-05-2019
11
Furthermore, a speaker device capable of attenuating the reaction force of the speaker can be
obtained by disposing only one speaker having a through hole in the above-described diaphragm
in the speaker box.
12-05-2019
12
Документ
Категория
Без категории
Просмотров
0
Размер файла
22 Кб
Теги
jph11243593
1/--страниц
Пожаловаться на содержимое документа