JP2007324644A - Speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speaker which is compact and yet has stable low frequency sound reproduction capability by improving a speaker having been widely used as a low frequency sound reproduction speaker including a speaker for acoustic equipment. <P>SOLUTION: The speaker can achieve stable low frequency sound reproduction without unbalancing a vibration system by arranging a vibration system weight adjustment weight 6 at nearly a center inside a voice coil 4 supported by a diaphragm 3 and a damper 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a speaker used for various audio equipment.

  In recent years, in vehicle interior acoustics, a system for controlling the engine noise, road noise, and the like outside the vehicle to make the vehicle interior a comfortable space, such as ANC (active noise control), is increasing. Briefly, ANC is a system that cancels noise by generating a sound having a phase opposite to engine noise and road noise at a speaker. A speaker that can stably reproduce a low frequency, which is a main frequency band of noise, is demanded by an ANC development manufacturer. In addition, there is a demand for contradictory performance that is small and lightweight and can be reproduced in a low frequency range. In terms of specific size, the development manufacturer demands a diameter of 60 mm and a total height of 35 mm or less. A conventional speaker used for such a purpose will be described with reference to a side sectional view of the speaker shown in FIG.

  According to the figure, reference numeral 11 is composed of a lower plate 11a having a center pole, a ring-shaped magnet 11b adhesively bonded to the lower plate 11a, and an upper plate 11c adhesively bonded to the ring-shaped magnet 11b. This is a magnetic circuit, and a magnetic gap 11d is formed between the center pole of the lower plate 11a and the inner peripheral surface of the upper plate 11c.

  Reference numeral 12 denotes a frame that is adhesively bonded to the upper plate 11c. Reference numeral 13 denotes an outer periphery that is adhesively bonded to the frame 12 through an edge portion. An inner periphery does not contact the magnetic circuit 11 in the magnetic gap 11d at the lower end side. The diaphragm is adhesively bonded to the voice coil 14 arranged as described above.

  Reference numeral 15 denotes a damper having an inner periphery adhesively bonded to the voice coil 14 and an outer periphery adhesively bonded to the bottom surface of the frame 12.

  Reference numeral 16 denotes a weight adjusting weight attached to the upper end portion of the voice coil 14, which attaches the weight adjusting weight 16 to the voice coil 14 which is a vibration system to make the vibration system heavy and perform low-frequency reproduction. It is.

  In addition, there is a special shape that uses two diaphragms 13 to increase the weight of the diaphragm itself, but there is a problem that the cost is high because the shape of the diaphragm is special.

For example, Patent Document 1 is known as prior art document information regarding a speaker using the weight adjustment weight 16.
Japanese Utility Model Publication No. 6-49038

  However, since the above-described conventional speaker only has a weight adjustment weight 16 mounted thereon as a separate part, the weight adjustment weight 16 is attached at a position where the weight adjustment weight 16 is installed at a relatively low cost. 14 may cause rolling when the diaphragm 13 swings, and there is a problem that adjustment for maintaining stable low-frequency reproduction is difficult. In the worst case, abnormal sound is generated. It was possible.

  The present invention can solve the above-mentioned problems and provide a low-frequency reproduction speaker excellent in performance at a low cost without changing the manufacturing process.

  In order to solve the above problems, a speaker according to the present invention has a vibration system weight adjustment weight disposed in an inner space of a voice coil, and is substantially at the center in both the circumferential direction and the vertical direction of the vibration system or supports the voice coil. By arranging the vibration system weight adjustment weight at substantially the center, it is possible to provide a speaker capable of suppressing the rolling of the voice coil and achieving stable low-frequency reproduction.

  The speaker according to the present invention places the weight center of gravity at the approximate center of both the circumferential direction and the vertical direction of the vibration system or the approximate center of the support of the voice coil by arranging the weight adjustment weight in the gap on the inner peripheral side of the voice coil. Thus, the weight balance is improved, the rolling that occurs at the time of the amplitude of the diaphragm is suppressed, and stable low-frequency reproduction is achieved.

  A speaker according to an embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1)
FIG. 1 is a side sectional view of a speaker according to an embodiment of the present invention, FIG. 2 is a sound pressure-frequency characteristic diagram, FIG. 3 is a side sectional view of a speaker of the same development example, and FIG. FIG. 5 is a pressure-frequency characteristic diagram, and FIG. 5 is a side sectional view of a speaker of another example of development.

  According to FIG. 1, reference numeral 1 is composed of a lower plate 1a having a center pole, an annular magnet 1b, and an upper plate 1c superposed thereon, and a magnetic gap is formed between the outer periphery of the center pole and the inner periphery of the upper plate 1c. 1d is a magnetic circuit, 2 is a frame bonded to the upper plate 1c, 3 is a cone-shaped diaphragm, and the outer periphery of the diaphragm 3 is bonded to the frame 2 via an edge. Are combined.

  Reference numeral 5 denotes a damper, and the outer periphery of the damper 5 is adhesively bonded to the frame 2.

  The inner peripheral portion of the diaphragm 3 and the inner peripheral portion of the damper 5 are adhesively bonded to the voice coil 4 fitted in the magnetic gap 1d, and the voice coil 4 is supported by the diaphragm 3 and the damper 5. Has been.

  Reference numeral 6 denotes a vibration system weight adjustment weight, which is disposed on the inner peripheral side of the voice coil 4 with an outer diameter substantially the same as or slightly smaller than the inner peripheral diameter of the voice coil 4.

  The weight balance between the vibration system weight adjustment weight 6 and the voice coil 4 supported at two locations between the diaphragm 3 and the damper 5 is the weight balance of the vibration system weight adjustment weight at the center of the support portion. The center of 6 is preferably positioned in both the circumferential direction and the vertical direction.

  However, as far as the vertical direction is concerned, it was confirmed that if it is about ± 20%, the balance with respect to the amplitude of the diaphragm is hardly lost, and rolling can be suppressed to achieve stable bass reproduction.

  FIG. 2 shows the sound pressure-frequency characteristic a.

  Regarding the circumferential direction, since the vibration system weight adjustment weight 6 is fitted in the voice coil 4, the error is negligible.

  In the speaker according to the present embodiment as described above, the vibration system weight adjustment weight 6 is disposed at the center of the support portion in the voice coil 4. A plurality of leg portions 6a extended to the upper end of the voice coil and an L-shaped hook portion 6b for hooking on the upper end surface of the voice coil.

  Although the description has been given on the assumption that there are a plurality of the foot portions 6a, it may be extended upward from the outside of the vibration system weight adjusting weight 6 over the entire circumference, and it may be divided into a plurality of portions. May be.

  Further, the vibration system weight adjusting weight 6 may be fixed in the voice coil 4 by adhesively bonding the hook portion 6b and the upper end surface of the voice coil 4.

  The vibration system weight adjustment weight 6 may be made of any material as long as it is a non-magnetic material. However, as long as it is used for a small speaker, it can be as much as possible. What has a high specific gravity and can be made small is desirable. For example, copper and aluminum are desirable for metal materials, but there is one aspect that is expensive to process. In addition, when a resin material is used, the securing of dimensions and processing costs can be suppressed, but there is a difficulty in miniaturization.

  Thus, another conceivable method is a method using a composite material of a metal material and a resin material.

  For example, by using a moldable resin material (specific gravity of approximately 10) in which polyamide (PA6) is kneaded with tungsten (specific gravity 19.3), the vibration system weight is small, heavy, and has good dimensional accuracy. An adjustment weight can be obtained. Note that since tungsten is a very expensive material, the same effect can be obtained by using other metals. A die-cast product is also a useful means.

  FIG. 3 is a side sectional view of the speaker of the development example of the present embodiment, and only differences from the embodiment of FIG. 1 will be described. The difference is the shape of the vibration system weight adjustment weight. In this development example, a dome-shaped vibration system weight adjustment weight 6c is used instead of the flat disk-shaped vibration system weight adjustment weight 6 of FIG. It is.

  Although the shape of the vibration system weight adjustment weight 6c is not limited to the flat shape as long as the balance in the vertical direction is not lost, the dome shape or the like improves the acoustic characteristics. Direction. FIG. 4 shows the sound pressure-frequency characteristic b. It is confirmed that the characteristic is smoother than that of FIG. 2, and distortion in the high range (first harmonic b1 and second harmonic b2). In addition, it was confirmed that the speaker of this development example was lower and improved than the distortion (first harmonic a1, second harmonic a2) of FIG.

  FIG. 5 is also a side sectional view of the speaker of the development example of the present embodiment, but only the difference from the present embodiment of FIG. 1 will be described. The tip of the hook portion 6e of the vibration system weight adjustment weight 6d is shown. The voice coil 4 and the diaphragm 3 extend downward to the adhesive application portion.

  With this configuration, the speaker assembly process can be simplified by simultaneously bonding the three points of the voice coil 4, the diaphragm 3, and the vibration system weight adjustment weight 6d.

  Note that the four points of the voice coil 4, the diaphragm 3, the vibration system weight adjusting weight 6d, and the damper 5 can be bonded simultaneously. As a result, the speaker assembly process can be further simplified.

  In the above description, the outer diameters of the vibration system weight adjustment weights 6, 6 c and 6 d are matched to the inner peripheral shape of the voice coil 4, and a cylindrical shape that is the same as or slightly smaller in diameter than the inner periphery of the voice coil 4 is assumed. As described above, as long as the center of gravity position of the vibration system weight adjustment weight can be held and fixed, the circumferential cross section may be elliptical or substantially pentagonal.

  In the speaker according to the present invention, the vibration system weight adjustment weight is arranged in the gap on the inner peripheral side of the voice coil of the speaker, and the center of gravity of the weight is provided at the approximate center of both the circumferential direction and the vertical direction of the vibration system or the support center of the voice coil. By placing the, the weight balance becomes good and the rolling that occurs when the diaphragm swings can be suppressed, and stable low-frequency reproduction can be achieved. ANC (active noise) such as low-frequency reproduction speakers and cars This is useful for use as a speaker for control.

1 is a side sectional view of a speaker according to an embodiment of the present invention. Same sound pressure vs. frequency characteristics Side sectional view of the speaker in the same development example Same sound pressure vs. frequency characteristics Side sectional view of the speaker in another development example Side view of a conventional speaker

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic circuit 1a Lower plate 1b Annular magnet 1c Upper plate 1d Magnetic gap 2 Frame 3 Diaphragm 4 Voice coil 5 Damper 6, 6c, 6d Vibration system weight adjustment weight 6a Foot part 6b, 6e Hook part

Claims (4)

A magnetic circuit having at least a magnetic gap, a frame coupled to the magnetic circuit, a diaphragm and a damper having an outer periphery adhesively coupled to the frame, and an inner periphery of the diaphragm and the damper are adhesively coupled to each other. A speaker comprising a voice coil partially disposed in a magnetic gap, wherein a vibration system weight adjustment weight is disposed in an inner circumferential space of the voice coil. The vibration system weight adjustment weight is a speaker in which the center of the vibration system weight adjustment weight is disposed at a position within ± 20% of at least the central portion of the voice coil supported by the diaphragm. 3. The speaker according to claim 1, wherein the vibration system weight adjusting weight is made of a metal material, a resin material, or a composite of the metal material and the resin material. At least the inner periphery of the diaphragm and the adhesive application range for adhesive bonding of the voice coil or the inner periphery of the diaphragm The speaker according to claim 1, wherein the speaker extends to an adhesive application range for adhesive bonding between the inner periphery of the damper and the voice coil.

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