JP2009094915A - Speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speaker that can realize thinning, can increase the sound pressure of a high output, and can reduce distortions and defective gaps by suppressing the rolling phenomenon. <P>SOLUTION: The speaker comprises first and second magnets 11, 13 arranged in a slanting direction or in a substantially horizontal direction via a magnetic gap 17; a voice coil body 16 arranged movably in the magnetic gap 17; a diaphragm 15 coupled to the voice coil body 16; a center pole 19 provided at the center of a lower plate 18; and a shaft 24 provided in the diaphragm 15. The first magnet 11 is provided on the lower surface at an outer-periphery edge 20 of the center pole; the second magnet 13 is provided on the upper surface of the lower plate 18, at a position which is farther out than that of the first magnet 11; and the shaft 24 is inserted into a through-hole provided at the center of the center pole 19, and a magnetic fluid 25 is interposed between the shaft 24 and the through-hole. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  A conventional speaker will be described with reference to FIG.

  FIG. 5 shows a cross-sectional view of a conventional speaker.

  According to FIG. 5, the magnetized magnet 1 is coupled to the lower plate 3 having the center pole 3A, and the upper plate 2 is coupled to the opposite side of the magnet 1 to which the lower plate 3 is coupled. A magnetic circuit 4 is configured.

  A frame 6 is coupled to the magnetic circuit 4, and a diaphragm 7 is coupled to the peripheral edge of the frame 6.

  A voice coil body 8 is coupled to the diaphragm 7 and the voice coil body 8 is inserted into the magnetic gap 5 of the magnetic circuit 4 to constitute a speaker.

  In this conventional speaker, as a configuration of the entire height, it is a so-called stacked configuration in which the frame 6 is coupled to the magnetic circuit 4.

  For this reason, the total height of the speaker requires a total size of the magnetic circuit 4 and the frame 6 at a minimum.

  Recently, in the AV product field, thin televisions such as liquid crystal and plasma have been widely used, and the demand for thinning all the dimensions of the speaker is becoming very strong.

  Also, in the mobile product field, the multifunction and thinning of mobile phones are remarkable, and in this field also, the demand for thinning the speaker is becoming very strong.

  On the other hand, in the in-vehicle field, demands for miniaturization, thinning, and weight reduction of speakers are becoming very strong as activities aiming at energy saving for the purpose of dealing with the global environment.

  Against this background, the development of downsizing, thinning, and high output of the above-described conventional speaker has been strengthened.

  Under these circumstances, in order to reduce the thickness and increase the output while maintaining the structure of the conventional speaker, the limit has already been reached due to strict market demands, and it has become necessary to add new structural reforms to the speaker. Yes.

  Therefore, recently, development of a speaker for realizing this thinning has been strengthened.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2005-51283 A

  The above-described conventional speaker has a problem that it has already reached the limit for strict market demand in order to reduce the thickness while maintaining the structure.

  Further, in the market demand, there is a strict demand for further improvement of the sound pressure level and lower distortion for improving the conversion efficiency of the speaker for the purpose of energy saving.

  In order to cope with these, it is necessary to use a magnet with a large volume or add a cancel magnet to form a repulsive magnetic circuit so that the magnetic energy of the magnet can be used efficiently.

  In any case, the conventional loudspeaker tends to increase the volume of the magnetic circuit including the magnet, and it has become more difficult to reduce the thickness.

  Also, when increasing the sound pressure of a high output in AV equipment, the voice coil body 8 which is a drive system component swings up and down like a pendulum at this large amplitude, thereby causing distortion and gap failure due to rolling. It also had a problem of generating abnormal sounds.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems, to realize a reduction in thickness, to increase a high output sound pressure, to prevent a rolling phenomenon, and to reduce a gap defect.

  In order to achieve this object, the present invention includes first and second magnets arranged obliquely or substantially horizontally through a magnetic gap, a voice coil body movably arranged in the magnetic gap, It consists of a diaphragm coupled to the voice coil body, a center pole provided at the center of the lower plate, and a shaft provided on the diaphragm, and the first magnet is disposed on the lower surface of the outer peripheral edge of the center pole. The second magnet is provided on the upper surface of the lower plate at a position outside the first magnet, the shaft is inserted into a through hole provided in the center of the center pole, and the shaft and the through hole are provided. And a magnetic fluid between them.

  The present invention uses two magnets, a first magnet and a second magnet, arranged obliquely or substantially horizontally through a magnetic gap, thereby generating a large driving force and increasing a high-output sound pressure. In addition, when the same output is provided, the thickness of the second magnet can be reduced, so that the overall height of the speaker can be reduced and the thickness can be reduced.

  In addition, the shaft provided on the diaphragm is inserted into the through hole provided in the center of the center pole, and a magnetic fluid is interposed between the shaft and the through hole, so that the voice coil body can be used even at a large amplitude. Thus, the distortion of the speaker and the gap defect can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a sectional view of the structure of the speaker of the present invention.

  In FIG. 1, a center pole 19 having an outer peripheral edge 20 is provided at the center of the lower plate 18.

  The first magnet 11 and the first plate 12 are disposed on the lower surface of the outer peripheral edge 20 of the center pole 19 by adhesion, and the second magnet 13 and the second plate 14 are connected to the first magnet 11 and the first plate 12. It is arrange | positioned by adhesion | attachment on the upper surface of the lower plate 18 in the position outside the position where this plate 12 is arrange | positioned.

  The first magnet 11 and the first plate 12 are arranged obliquely or substantially horizontally with the second magnet 13 and the second plate 14, and the lower plate 18, the center pole 19, and the first magnet. 11, the first plate 12, the second magnet 13, and the second plate 14 constitute a magnetic circuit. The magnetic circuit having such a configuration is called an outer magnet type oblique magnetic circuit.

  The magnetic gap 17 is formed by the first magnet 11, the first plate 12, the second magnet 13, and the second plate 14 so as to open toward the upper surface side.

  The voice coil body 16 has a structure in which the coil 23 is wound around the outer periphery of the bobbin 22, and is disposed so as to be movable in the vertical direction with respect to the magnetic gap 17. It has a structure that serves as an axis for vibrating the connected diaphragm 15.

  The diaphragm 15 has an outer peripheral portion connected to the frame 21 and a shaft 24 provided at the center of the diaphragm 15. The shaft 24 is inserted into a through hole provided in the center of the center pole 19 and a magnetic fluid 25 is interposed between the shaft 24 and the through hole.

  FIG. 2 is a diagram showing magnetic field analysis of the voice coil portion in the magnetic gap of the speaker of the present invention.

  The magnetic flux emitted from the N pole on the upper surface of the second magnet 13 enters inward in a substantially horizontal direction in the magnetic gap 17 and enters the S pole on the lower surface of the first magnet 11. In the coil 23 portion of the magnetic gap 17, there is a magnetic flux that is substantially perpendicular to the vibration direction of the diaphragm effective for driving, that is, substantially perpendicular to the coil 23 portion of the voice coil body 16, as indicated by a white arrow. It has come to be obtained.

  Then, by applying an audio signal to the coil 23 of the voice coil body 16, the voice coil body 16 reacts with the magnetic field of the magnetic gap 17 to drive the voice coil body 16 in the vertical direction. Sound is transmitted.

  Since the speaker of the present invention comprises the magnetic gap 17 using the two magnets of the first magnet 11 and the second magnet 13, a large driving force can be generated in the voice coil body 16, As a result, the sound output by the diaphragm 15 can be increased.

  Also, when designing a speaker that outputs the same output, the volume of the second magnet can be reduced compared to the conventional configuration using only one magnet, so the second The height of the magnet can be kept low, the overall height of the speaker can be reduced, and the thickness can be reduced.

  In addition, since the configuration of the magnetic circuit of the present invention is a so-called outer magnet type configuration, a space for arranging the second magnet 13 provided on the upper surface of the lower plate 18 can be increased, so that it is not like a ferrite magnet. An inexpensive magnet can be used.

  Further, by inserting the shaft 24 provided in the center portion of the diaphragm 15 into the through hole provided in the center of the center pole 19 and having the magnetic fluid 25 interposed between the shaft 24 and the through hole, Even when the amplitude is large, the rolling phenomenon of the voice coil body 16 can be suppressed and the distortion of the speaker and the gap defect can be reduced.

  FIG. 3 is a perspective view in which the structure of the speaker of the present invention is applied to a circular speaker, and half of the circular speaker is cut out.

  In this configuration, the first magnet 11, the first plate 12, the second magnet 13, and the second plate 14 are annular magnets and plates. Similarly, the voice coil body 16 and the diaphragm 15 are of course circular.

(Embodiment 2)
FIG. 4 is a perspective view in which the structure of the speaker of the present invention is applied to an elongated speaker, and half of the elongated speaker is cut out.

  In this configuration, the first magnet 11, the first plate 12, the second magnet 13, and the second plate 14 use rod-like magnets and plates having a plate-like elongated rectangular body, and the length of the elongated speaker. Arranged in the direction.

  In selecting the material of the rod-shaped magnet, the first magnet 11 and the second magnet 13 are both neodymium magnets, the first magnet 11 and the second magnet 13 are both ferrite-based magnets, and the first magnet. A combination of a neodymium magnet 11 and a ferrite magnet can be considered for the second magnet 13.

  Further, in configuring this elongated speaker, it is necessary to limit the first magnet 11, the first plate 12, the second magnet 13, and the second plate 14 to a rod-like shape having a plate-like elongated rectangular body. Of course, a plate-like elliptical magnet and plate may be used.

  Also in the elongated speaker of the present invention, a speaker having the same effect as that of Embodiment 1 can be realized.

  The loudspeaker of the present invention can generate a large driving force by using two magnets to increase the high-output sound pressure, and can reduce the overall height of the loudspeaker so that it can be thinned. Since it can suppress and reduce distortion and gap defects, it is useful for thin speakers used in various audio equipment.

Cross-sectional view of the structure of the speaker of the present invention The figure which shows the magnetic field analysis of the voice coil part in the magnetic gap of the speaker of this invention The perspective view which cut off half of the circular speaker of this invention The perspective view which cut off half of the elongate type speaker of this invention Cross-sectional view of a conventional speaker structure

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st magnet 12 1st plate 13 2nd magnet 14 2nd plate 15 Diaphragm 16 Voice coil body 17 Magnetic gap 18 Lower plate 19 Center pole 20 Center pole outer peripheral part 21 Frame 22 Bobbin 23 Coil 24 Shaft 25 Magnetic fluid

Claims (5)

First and second magnets disposed obliquely or substantially horizontally through a magnetic gap, a voice coil body movably disposed in the magnetic gap, a diaphragm coupled to the voice coil body, and a lower plate And a shaft provided on the diaphragm, the first magnet is provided on the lower surface of the outer peripheral edge of the center pole, and the second magnet is the first magnet. Provided on the upper surface of the lower plate at a position outside the shaft, the shaft is inserted into a through hole provided in the center of the center pole, and a magnetic fluid is interposed between the shaft and the through hole. Speaker. The speaker according to claim 1, wherein the first and second magnets are magnetically coupled to form a magnetic circuit. The speaker according to claim 1, wherein the first and second magnets are annular magnets. The speaker according to claim 1, wherein the first and second magnets are plate-like bar magnets. The speaker according to claim 1, wherein the first and second magnets are arranged in the voice coil portion in the magnetic gap so that the magnetic flux is substantially orthogonal to the voice coil portion.

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