close

Вход

Забыли?

вход по аккаунту

JP2003219496

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 JP2003219496
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
electrodynamic speaker having a magnetic circuit in which a magnet is magnetically repelled.
[0002]
2. Description of the Related Art In recent years, along with space saving of audio equipment and
the like, there has been an increasing demand for smaller and lighter speakers mounted on these.
Since downsizing of the magnetic circuit is effective in reducing the size and weight of the
speaker, Nd-Fe-B based magnets having a high energy product are often used. Since the Nd-Fe-B
based magnet is expensive, the magnetic circuit is also required to have high efficiency from the
viewpoint of cost. In addition, in particular, in the case of in-vehicle speakers, many full-range
speakers that reproduce the entire audible band are used.
[0003]
Here, a conventional speaker will be briefly described with reference to FIG. In the figure, 21 is a
top plate, 22 is a vertically magnetized magnet, 23 is an under plate, 24 is a yoke, 25 is a voice
coil, 26 is a voice coil bobbin, 27 is a diaphragm, 28 is an edge, 29 is a damper , 30 is a frame,
31 is a dust cap. In order to realize a magnetic circuit with the outer peripheral portion of the top
plate 21 and the inner peripheral surface of the yoke 24, magnetic flux from the top plate 21 is
13-05-2019
1
set to at least the diameter of the magnet 22 up to the diameter of the top plate 21 forming the
magnetic gap. Leaked to the
[0004]
SUMMARY OF THE INVENTION In order to make a speaker having the above structure into a full
range speaker, it is necessary that the vibration system composed of the voice coil 25, the voice
coil bobbin 26, and the dust cap 31 be lightweight. The voice coil 25 should also be lightweight.
In order to reduce the weight of the voice coil 25 by making the direct current resistance of the
voice coil 25 constant, the wire diameter is small and the wire length is short. The voice coil 25 is
present in the magnetic gap, generates a driving force according to the electric signal, and
transmits the driving force to the diaphragm 27 through the voice coil bobbin 26, so a highly
efficient internal magnetic type magnetic circuit is used. In order to obtain a full-range speaker,
the diameter of the magnet 22 is small, so the amount of magnetic flux supplied to the magnetic
gap is small, and the driving force generated in the voice coil 25 is also small. That is, the
efficiency of the speaker was lowered, and a sufficient volume could not be obtained. In addition,
Joule heat is generated from the voice coil 25 by the current flowing through the voice coil 25,
but if the heat can not be dissipated efficiently, the voice coil 25 is broken, which makes it
difficult to achieve high input resistance. The
[0005]
Conversely, although it is sufficient to increase the diameter of the magnet 22 in order to obtain
a sufficient driving force, the efficiency of the magnetic circuit decreases, and the weight, volume,
and cost increase. Further, if the wire diameter of the voice coil 25 is increased and the driving
force is increased by the wire length, the voice coil 25 becomes heavy, high frequency
reproduction is disadvantageous, and a full range speaker can not be realized.
[0006]
SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention
according to claim 1 of the present invention is disposed at least in the direction to magnetically
repel the center plate and the lower and upper surfaces of the center plate. First and second
magnets, a top plate disposed on the upper surface of the second magnet, an under plate
disposed on the lower surface of the first magnet, and an outer peripheral portion of the under
plate A yoke provided so as to form a magnetic gap with the outer peripheral portion of the plate,
a voice coil wound around a voice coil bobbin which exists in the magnetic gap and generates a
13-05-2019
2
driving force in accordance with an electrical signal, a voice A diaphragm attached to the coil
bobbin, an edge joined to the outer peripheral portion of the diaphragm, a damper joined to and
supported by the voice coil bobbin or the diaphragm, a yoke, Center frame and the outer
periphery of the rim are joined together, the second magnet and the top plate have the same
inner diameter and outer diameter, and the second magnet and the top plate are smaller than the
outer diameter of the center plate; A convex portion smaller than the thickness of the second
magnet on the upper surface of the second magnet, and the convex portion of the center plate
substantially engages with the outer peripheral portion or the inner peripheral portion of the
second magnet; The speaker has a structure in which the top surface positional relationship of
each yoke sets the top surface of the yoke in the range from the top surface of the center plate to
the top surface of the top plate. A speaker that has a structure that substantially mates with the
inner circumference, and is arranged to magnetically repel the second magnet on the top surface
of the center plate, so that it is possible for the magnetic gap to be efficient. One in which can
supply sufficient magnetic flux.
[0007]
Furthermore, by making the second magnet annular, the operating point can be set high without
increasing the thickness of the magnet, and furthermore, by providing the annular top plate on
the top surface of the second magnet, the operation in the magnet is achieved. Since the points
can be made uniform, high temperature demagnetization is difficult.
In addition, the configuration in which the convex portion of the center plate is substantially
fitted to the outer peripheral portion or the inner peripheral portion of the second magnet not
only facilitates positioning in a method, but also for the second magnet. It serves as a guide to
prevent misalignment in the horizontal direction and helps to improve product reliability.
[0008]
The heat generation of the voice coil can be efficiently dissipated by having a structure in which
the top surface of the yoke is set in the range from the top surface of the center plate to the top
surface of the top plate to the top surface of the center plate and the yoke. It is possible to
achieve higher input tolerance.
[0009]
In the invention according to claim 2 of the present invention, the entire lower surface of the
second magnet is the center plate even at the maximum eccentricity of the second magnet
13-05-2019
3
generated due to the space between the convex portion of the center plate and the fitting portion
of the second magnet. A configuration is provided in the upper surface, and a clearance is
intentionally provided in the fitting of the convex portion of the second magnet and the top plate
to improve the methodic ease, and the eccentricity of the second magnet. Even in the case where
a problem occurs, the second magnet is prevented from protruding into the magnetic gap.
[0010]
The invention according to claim 3 of the present invention is a speaker in which the convex
portion of the center plate has a single disk shape or ring shape and is disposed concentrically
with the center plate, and the convex portion of the center plate has a simple shape. As well as
facilitating the formation of the center plate, as in the first aspect of the invention, it serves as a
guide for preventing the horizontal displacement of the second magnet, thereby improving the
reliability of the product.
[0011]
According to a fourth aspect of the present invention, there is provided a speaker in which a
plurality of convex portions of the center plate are arranged on concentric circles of the center
plate, and in the same manner as in the first aspect It serves as a guide and helps to improve
product reliability.
Furthermore, by arranging a plurality of convex portions of the center plate, it is possible to
reduce the area with the convex portions of the center plate which approaches the top surface of
the second magnet and magnetically attracts each other. The magnetic leakage from the second
magnet to the convex portion of the center plate is reduced, so that the magnetic flux of the
second magnet can be concentrated to the magnetic gap side.
[0012]
In the invention according to claim 5 of the present invention, the center plate, the first magnet,
and the hole in the center portion of the under plate, the nonmagnetic rod-like or cylindrical
rivets It is a speaker which was enlarged on the upper surface side of the plate to connect the
underplate, the first magnet and the center plate, and the diameter of the rivet on the upper
surface side of the center plate is at least smaller than the inner diameter of the second magnet,
The rivets provide a strong bond between the center plate, the first magnet, and the under plate,
13-05-2019
4
thereby improving product reliability.
Furthermore, it becomes possible to bond-free these parts that were normally joined by adhesion,
and it is possible to eliminate the magnetic resistance caused by the presence of the adhesive
layer, and therefore the efficiency of the magnetic circuit can be enhanced.
[0013]
In the invention according to claim 6 of the present invention, the diameter of the hole of the
center plate and the diameter of the hole of the under plate are equal and at least equal to the
diameter of the hole of the first magnet. A speaker in which the minimum width formed by the
outer peripheral surface of the first magnet and the inner peripheral surface of the yoke at the
time of maximum eccentricity of the first magnet caused by the difference in diameter of the
holes is equal to or less than the width of the magnetic gap, At the time of maximum eccentricity
of the first magnet, the minimum width formed by the outer peripheral surface of the first
magnet and the inner peripheral surface of the yoke is larger than that of the magnetic air gap,
thereby making the first magnet maximum. Even if eccentricity occurs, the gap formed by the
outer circumferential surface of the first magnet and the inner circumferential surface of the
yoke is larger than the width of the magnetic gap through which the voice coil and voice coil
bobbin move when the speaker is driven. Does not inhibit migration
In addition, although it generally requires polishing to increase the dimensional accuracy of the
hole, the cost is increased, but such a configuration can eliminate the need for high-precision
machining of the hole of the first magnet, It also becomes easy in terms of construction method.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will
be described below with reference to FIGS.
[0015]
(First Embodiment) FIG. 1 is a structural cross-sectional view of an embodiment of a speaker
according to the present invention, and FIG. 2 (a) is a structural cross-sectional view of a
magnetic circuit portion which is an essential part of the same spread example. 2 (b) is a
13-05-2019
5
structural cross-sectional view of a magnetic circuit portion which is a main part of the other
development example, and mainly described in claims 1 to 3.
According to the figure, 1 is a center plate, 2 is a vertically polarized first magnet, 3 is a vertically
polarized second magnet so as to magnetically repel the first magnet 2, 4 Is a top plate, 5 is an
under plate, 6 is a yoke, 7 is a voice coil, 8 is a voice coil bobbin, 9 is a diaphragm, 10 is an edge,
11 is a damper, 12 is a frame, and 13 is a dust cap.
[0016]
Next, the detailed configuration of the above-described embodiment will be described along with
the operation.
[0017]
The magnetic flux emitted from the first magnet 2 flows into the lower surface of the center plate
1 and passes through the magnetic gap formed by the outer peripheral surface of the center
plate 1 and the inner peripheral surface of the yoke 6. , And returns to the first magnet 2.
On the other hand, the magnetic flux emitted from the second magnet 3 flows into the upper
surface of the center plate 1, most of which passes through the magnetic gap and passes through
the yoke 6 and the top plate 4 to the first magnet 2. I will return. By magnetically repelling the
first magnet 2 and the second magnet 3 and arranging the center plate 1 in the vicinity of the
magnetic gap, a large amount of magnetic flux emitted from the first magnet 2 and the second
magnet 3 can be obtained. Since the part can be made to leak to the magnetic gap, a highly
efficient magnetic circuit can be realized.
[0018]
Further, since the second magnet 3 has a large gap between the yoke 6 and the top plate 4 and
the magnetic resistance is increased, the operating point of the second magnet 3 becomes a
smaller value than that of the first magnet 2 . Generally, the operating point of the magnet
decreases as the magnetic resistance of the magnetic circuit increases, and decreases as the
thickness in the direction of magnetization decreases. As in the present invention, the operating
point can be set high by making the second magnet 3 annular and making the thickness in the
13-05-2019
6
magnetization direction relatively thick as viewed from the entire second magnet 3. Further, by
providing the annular top plate 4, the internal magnetic flux density of the second magnet 3 can
be made uniform, and the operating point is stabilized.
[0019]
Furthermore, at the time of operation of the speaker, the heat generation of the voice coil 7
causes the first magnet 2 and the second magnet 3 to have a high temperature, particularly when
the input is large. In order to realize a small magnetic circuit, high energy demagnetization
becomes a problem when the operating point is low if high energy Nd-Fe-B magnets are used, but
the annular second magnet 3 and the annular top plate 4 is intended to ensure stability of the
operating point of the second magnet 3 and to take measures against high temperature
demagnetization.
[0020]
Further, the top surface positional relationship between the center plate 1 and the yoke 6 has a
structure in which the top surface of the yoke 6 is set in the range from the top surface of the
center plate 1 to the top surface of the top plate 4. The heat can be dissipated efficiently, and
higher input resistance can be achieved.
[0021]
A driving force is generated in response to the electric signal in the voice coil 7 disposed in the
magnetic gap, and the driving force increases as the magnetic flux density of the magnetic gap
increases, and further increases as the wire length of the voice coil 7 increases.
[0022]
In the case of a full-range speaker that reproduces the entire audible band with a single speaker,
the vibration system needs to be lightweight, and the voice coil 7 having a metal wire with
specific gravity must also be lightweight, which is inevitable. In order to make the wire diameter
of the voice coil 7 small and to shorten the wire length to make the voice coil 7 having a specific
DC resistance value, the voice coil 7 is designed to be small.
[0023]
Since the voice coil 7 is disposed in the magnetic air gap, the diameter of the first magnet 2 is
smaller than that of the voice coil 7, but by disposing the repelled second magnet 3 as in the
13-05-2019
7
present invention, Since sufficient magnetic flux, ie, magnetic flux density, can be obtained in the
magnetic gap, a compact magnetic circuit can realize a full range speaker having sufficient
driving power.
[0024]
The operation in the case where a general speaker is configured using the above magnetic circuit
will be briefly described.
The driving force generated in the voice coil 7 disposed in the magnetic gap drives the
diaphragm 9 through the voice coil bobbin 8 to emit a sound wave.
The yoke 6 and the frame 12 are fixed, the inner and outer peripheral portions of the damper 11
are respectively coupled to the voice coil bobbin 8 and the frame 12, and the inner and outer
peripheral portions of the edge 10 are respectively connected to the outer peripheral portion of
the diaphragm and the frame 12 The damper 11 and the edge 10 are joined to allow the
vibration of the voice coil 7, the voice coil bobbin 8 and the diaphragm 9, and serve as a support
member.
The dust cap 13 is joined to the inner peripheral portion of the diaphragm 9 for dust prevention.
[0025]
In addition, when the center plate 1 and the second magnet 3 are bonded by bonding, the
bonding area is small because the second magnet 3 is annular, and the bonding strength is not
necessarily large.
Since the magnetic attraction force acts on the upper surface of the center plate 1 and the lower
surface of the second magnet 3, the possibility that they are separated in the vertical direction is
extremely small. Therefore, in order to improve the reliability of the speaker as a product, it is
preferable to prevent lateral displacement of the second magnet 3 and to avoid collision with the
voice coil 7 or the voice coil bobbin 8.
13-05-2019
8
[0026]
Therefore, by providing a convex portion 1a at the central portion of the center plate 1 and
fitting it to the second magnet 3, the horizontal displacement of the second magnet 3 is
prevented, and the reliability of the product is enhanced. In addition, since the convex portion 1a
of the center plate 1 serves as a guide for the second magnet 3, the method is easy in
construction.
[0027]
Further, in order to make assembling of the center plate 1 and the second magnet 3 easier in
terms of the method, the outer diameter of the convex portion 1a of the center plate 1 and the
inner diameter of the second magnet 3 are easily fitted with a slight difference. It should be made
to match.
At this time, if the dimensional relationship is set so that the lower surface of the second magnet
3 always exists in the range of the upper surface of the center plate 1 at the maximum
eccentricity of the second magnet 3, the vibration of the voice coil 7 or the voice coil bobbin 8
The second magnet 3 does not disturb. Furthermore, the magnetic resistance of the upper
portion of the second magnet 3 and the convex portion 1a of the center plate 3 is secured large,
and the height of the convex portion 1a is set to the necessary minimum in order not to increase
the amount of magnetic flux therebetween. .
[0028]
In FIG. 1, the disk-shaped convex portion 1a having a simple shape is easily provided at the
central portion of the center plate 3 in terms of parts construction method, and the inner
peripheral side of the second magnet 3 is fitted. For example, although only the magnetic circuit
portion is shown, as shown in FIG. 2A, the convex portion 1b of the center plate 1 may be
annular, and as shown in FIG. An annular convex portion 1 c may be provided on the outer
peripheral portion to be fitted with the outer peripheral portion of the second magnet 3.
[0029]
Furthermore, the diaphragm 9, the edge 10, the damper 11, the frame 12 and the dust cap 13
shown in FIG. 1 are general ones up to an example and may not be limited thereto.
13-05-2019
9
[0030]
(Second Embodiment) A fourth embodiment of the speaker according to the present invention
will be mainly described with reference to FIGS. 3 (a) and 3 (b).
FIG. 3 (a) is a top view of the magnetic circuit part which is the main part, and FIG. 3 (b) is a
sectional view of the same structure.
About the number in a figure, the same part as Embodiment 1 attached the same number. A large
difference from the first embodiment is that a plurality of convex portions 1d of the center plate
are partially provided.
[0031]
Next, the detailed configuration of the above-described embodiment will be described along with
the operation. The operation is the same as that of the first embodiment. The difference is that,
since a plurality of projections 1 d on the upper surface of the center plate 1 are partially
provided, the total area of the upper surfaces of the projections 1 d can be made smaller than in
the first embodiment. Therefore, the magnetic resistance between the convex portion 1d and the
upper surface of the second magnet 3 is increased, and the amount of magnetic flux flowing out
during this time is decreased, and the amount of magnetic flux to the magnetic gap is increased
to improve the efficiency of the magnetic circuit. Have the advantage of
[0032]
In the drawing, the convex portion 1 d on the upper surface of the center plate 1 is in the form of
three disks, but this number and shape are merely an example, and it is not limited to this.
[0033]
Third Embodiment Another embodiment of the speaker according to the present invention will
be described mainly with reference to FIGS. 4A and 4B.
13-05-2019
10
FIG. 5 is a structural cross-sectional view of a magnetic circuit portion which is a main portion.
14 in the figure is a rivet. The same reference numerals as in the first embodiment denote the
same parts in FIG. A major difference from the first embodiment is that a hole is provided at the
center of the center plate 1, the first magnet 2 and the under plate 5, and the rivet 14 couples
the first magnet 2 to the center plate 1 from the under plate 5. It is
[0034]
Next, the detailed structure of the above embodiment will be described along with the operation.
The operation is the same as that of the first embodiment. The difference is that a hole is
provided at the center of the center plate 1, the first magnet 2 and the under plate 5, and the
rivet 14 firmly connects the first magnet 2 and the center plate 1 from the under plate 5 to
achieve product reliability. To raise The necessity of this coupling method is briefly explained.
[0035]
Since the outer peripheral surface of the center plate 1 and the inner peripheral surface of the
yoke 6 form a magnetic gap, a large magnetic attraction acts on these.
[0036]
Although the first magnet 2 bonded to the under plate 5 and the under plate 1 bonded to the
first magnet 2 are bonded if a conventional general method is applied, the adhesive has bonding
strength at high temperature It is preferable that these junctions be mechanically coupled,
because they are reduced, and the small magnetic circuit tends to have a high temperature when
driving the speaker because the heat capacity is small.
[0037]
Since the magnetic resistance in the magnetic path formed by the center plate 1 and the
magnetic gap, the yoke 6 and the under plate 5 as viewed from the center plate 1 and the first
magnet 2 decreases, the magnetic flux in the magnetic gap increases. Do.
The center plate 1, the first magnet 2, the under plate 5, and the yoke 6 are joined and
magnetized, the second magnet 3 and the top plate 4 are joined and magnetized, and these two
blocks are joined. Since the process of completing the magnetic circuit is realistic, it is effective to
13-05-2019
11
connect the center plate 1, the first magnet 2 and the under plate 5 with the rivets 14 instead of
the entire magnetic circuit.
The shape of the rivet 14 in the drawing is not limited to this, and is just an example. For
example, the shape may be hollow, and the rivet 14 may be a bolt.
[0038]
The holes of the center plate 1 and the holes of the under plate 5 have the same diameter, and
the diameter of the first magnet 2 is larger than the diameter of the holes of the center plate 1
and the diameter of the holes of the under plate 5. Even at the maximum eccentricity of the first
magnet 2 caused by the difference between the diameter and the diameter of the first magnet 12,
the distance between the outer peripheral surface of the first magnet 2 and the inner peripheral
surface of the yoke 6 The diameter of the first magnet 2 was set to be smaller than that.
Generally, in the case of using a high energy sintered Nd-Fe-B based magnet, polishing is
required to ensure the dimensional accuracy of the outer shape.
[0039]
Therefore, if the hole of the first magnet 2 is made large beforehand and the hole of the diameter
which can always insert the rivet 14 is set, the polishing process of the hole of the first magnet 2
can be omitted to reduce the cost. Become. Furthermore, as described above, by setting the
diameter of the hole of the first magnet 2 to be larger than the diameter of the hole of the center
plate 1 and the diameter of the hole of the under plate 5, It has the advantage of facilitating the
insertion of the rivet 14 without requiring strict positioning.
[0040]
As described above, according to the present invention, it is possible to provide a small-sized,
high-efficiency magnetic circuit which can supply sufficient magnetic flux to the magnetic gap, is
easy in terms of method, and has high reliability. It is possible to realize a full range speaker
capable of reproducing sound volume and efficiently radiating Joule heat generated from the
voice coil, thereby achieving high input resistance.
13-05-2019
12
1/--страниц
Пожаловаться на содержимое документа