JP2007336293A - Electromagnetic converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electromagnetic converter having stable operation performance regardless of the technique of an assembling worker by allowing a vibration not to be disturbed in a diaphragm and appropriately arranging and fixing the diaphragm in a short time. <P>SOLUTION: A structural body 2 is obtained by laminating a lower permanent magnetic board 11 having a plurality of belt shape magnetization parts, a buffering member 12a, the diaphragm 13 having tongue shape pieces 13c at edge ends, a buffering member 12b, and an upper permanent magnetic board 14 having the plurality of belt shape magnetization parts. The structural body 2 is enclosed with frames 3. The tongue shape pieces 13c are pinch-held in the connection of a lower frame 31 and an upper frame 32 constituting the frames 3, so as to support the diaphragm 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic transducer that reproduces audible sound by supplying an audio signal to a coil pattern formed on a vibrating membrane.

In an electromagnetic transducer in which a permanent magnet and a vibrating membrane are combined, a permanent magnet plate and a vibrating membrane are arranged to face each other, and a buffer member is interposed therebetween. The permanent magnet plate, the vibration film, and the buffer member are covered with a frame member and attached to the speaker housing.
The permanent magnet plate has a band-shaped magnetized portion where the polarity is alternately changed at regular intervals. Further, the vibration film is opposed to a gap portion of different polarity of the permanent magnet plate, a so-called magnetized neutral zone, and a meandering conductor pattern acting as an electromagnetic coil is formed on the vibration film. . When the current of the audio signal flows through the coil pattern, the coil pattern and the magnetized portion of the permanent magnet plate are electromagnetically coupled, and the diaphragm having the coil pattern vibrates according to Fleming's law to perform audio reproduction (for example, , See Patent Document 1).

Japanese Patent Laid-Open No. 9-331596 (pages 3 to 5, FIGS. 1 and 2)

  Since the conventional electromagnetic transducer is configured as described above, when assembling the electromagnetic transducer, the coil pattern formed on the vibrating membrane is composed of the S pole magnetized portion and the N pole of the permanent magnet plate. Place the vibration film at the optimal position while observing the magnetization pattern of the permanent magnet plate with a magnet viewer etc. so that it is placed in the middle of the magnetized part, and attach adhesive tape etc. to a part of the vibration film. It is fixed to a nearby member. For this reason, it takes time to align and fix the diaphragm, and the number of assembling steps increases, and depending on the skill of the operator, the above-mentioned tape application position varies, making it difficult to fix the diaphragm in the same way and playing audio. There has been a problem that individual differences occur in the operation performance.

  The present invention has been made to solve the above-described problems, and the vibration film can be appropriately arranged and fixed in a short time so as not to disturb the vibration of the vibration film. It is an object of the present invention to obtain an electromagnetic transducer having a stable operation performance regardless of the skill of an operator.

  In the electromagnetic transducer according to the present invention, the diaphragm is provided with a tongue-like piece projecting from an edge portion of the diaphragm, and the tongue-like piece is narrowed at a joint portion between the first frame and the second frame forming the frame. It is held and supports the vibrating membrane.

  According to the present invention, the tongue-like piece projecting from the edge portion of the vibration film is supported between the first frame and the second frame so as to support the vibration film. The vibration membrane can be fixed in a short time so as not to hinder the performance, and it is possible to stabilize the performance by suppressing the individual difference generated in the assembly work and to improve the reliability of the electromagnetic transducer. .

An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is an exploded perspective view showing a configuration of an electromagnetic transducer according to Embodiment 1 of the present invention. The illustrated electromagnetic transducer 1 includes a structure 2 and a frame 3 that covers the structure 2. The structure 2 is configured by stacking sheet-like or plate-like components. Here, a permanent magnet plate provided with a sound radiation hole for radiating the generated audible sound to the outside is referred to as an upper permanent magnet plate, and a permanent magnet plate disposed to face the upper permanent magnet plate is referred to as a lower permanent magnet plate. . In the structure 2, a buffer member 12 a is stacked on the upper side of the lower permanent magnet plate 11 disposed in the lowermost layer, and a vibration film 13 is stacked on the upper side. A buffer member 12b is laminated on the upper side of the vibration film 13, and an upper permanent magnet plate 14 is laminated on the upper side. The upper permanent magnet plate 14 has a plurality of sound radiation holes 14a penetrating in the vertical direction in the figure.

1 is formed so as to form a rectangle when the structure 2 is viewed from above in the drawing, and a frame 3 is also formed so as to surround the entire structure 2 having such a shape. Has been. As described above, the vibration film 3 constituting the structure 2 has a rectangular film shape, and the lower permanent magnet plate 11, the upper permanent magnet plate 14, and the buffer members 12a and 12b are formed in accordance with the film shape. Has been.
The lower permanent magnet plate 11 has a band-shaped magnetized portion of a sintered ferrite magnet, and is magnetized almost entirely on the surface of the magnet plate so that S poles and N poles are alternately arranged. Hereinafter, such a parallel striped magnetization pattern is referred to as a multipolar magnetization pattern.
The buffer member 12 a is inserted between the vibration film 13 and the lower permanent magnet plate 11 as described above, and the buffer member 12 b is inserted between the vibration film 13 and the upper permanent magnet plate 14. Is. The buffer members 12a and 12b prevent contact between the vibration film 13 that vibrates when the electromagnetic transducer 1 is operated and each magnet plate, so that no abnormal noise is generated. Those having a thickness, hardness and the like that have little influence are used.

The vibration film 13 is formed by forming a meandering conductive pattern acting as an electromagnetic coil on a thin resin film 13a such as flexible polyimide. Hereinafter, the meandering conductive pattern is referred to as a meandering coil pattern 13b. In addition, the meandering coil pattern 13b is laminated in the resin film 13a so that the electromagnetic action reaches both sides of the resin film 13a. The vibration film 13 illustrated here is formed such that the shape of the resin film 13a, that is, the film shape forms a rectangle. The meandering coil pattern 13b is provided so as to have a long linear portion in the longitudinal direction of the resin film 13a.
Further, the vibrating membrane 13 is provided with tongue-like pieces 13c extending in the short direction in the rectangular resin film 13a as described above, for example, at the four corners of the rectangular surface. Each tongue-like piece 13c is integrally formed with the resin film 13a.

The upper permanent magnet plate 14 is magnetized in the same manner as the lower permanent magnet plate 11 described above. A plurality of sound radiation holes 14a provided in the upper permanent magnet plate 14 are provided in correspondence with the position of the meandering coil pattern 13b of the vibration film 13 arranged in the lower layer.
The frame 3 is composed of an upper frame 32 and a lower frame 31. For example, by fitting fitting portions provided on the upper frame 32 and the lower frame 31, for example, a hexahedral box-shaped frame 3. Is formed. As illustrated in FIG. 1, when the lower frame 31 has a flat plate shape, the upper frame 32 is formed in a box having no bottom end surface, that is, a box having an opening portion below. The frame 3 is made of a ferromagnetic material such as iron, and is configured to act as a yoke material for the lower permanent magnet plate 11 and the upper permanent magnet plate 14.

FIG. 2 is an explanatory diagram showing the configuration of the electromagnetic transducer according to the first embodiment. This figure shows a schematic aspect of the internal cross section of the electromagnetic transducer 1 taken along line AA 'shown in FIG. 1 with a dashed line. The same reference numerals are used for the same parts as those shown in FIG. Is omitted. In FIG. 2, only the components essential for the operation of the electromagnetic transducer are shown, and the buffer members 12 a and 12 b are not shown for easy understanding of the cross-sectional configuration and the magnetic action.
As shown in FIG. 2, a plurality of sound radiation holes 32a are provided on the upper surface of the upper frame 32. The sound radiation holes 32a communicate with the sound radiation holes 14a of the upper permanent magnet plate 14 when the frame 3 sandwiches the structure 2. It has been.
As shown in FIG. 2, the basic configuration of the completed electromagnetic transducer 1 includes a vibration film 13 formed of two permanent magnet plates, that is, a lower permanent magnet plate 11 and an upper permanent magnet plate 14 as shown in FIG. It becomes the structure inserted | pinched from the upper and lower sides via 12b. The lower permanent magnet plate 11 and the upper permanent magnet plate 14 are formed with a multipolar magnetization pattern as described above. This multipolar magnetization pattern is obtained by magnetizing each magnet plate such that when the electromagnetic transducer 1 is assembled and the lower permanent magnet plate 11 and the upper permanent magnet plate 14 are laminated, the magnetized portions of the same polarity overlap. It has been made. A so-called neutral zone nz of magnetization is generated in the gap between the N pole magnetized portion and the adjacent S pole magnetized portion of the lower permanent magnet plate 11 and the upper permanent magnet plate 13.

The meandering coil pattern 13b provided in the vibration film 13 is configured such that when the vibration film 13 is sandwiched between the lower permanent magnet plate 11 and the upper permanent magnet plate 14 via the buffer members 12a and 12b and laminated, The linear portion of the meandering coil pattern 13b in the longitudinal direction is arranged at a position that is a gap between the belt-like N pole and S pole, that is, at the position of the belt-like neutral zone nz. The linear portions in the longitudinal direction of the meandering coil pattern 13b are arranged in parallel at regular intervals, and are parallel to the belt-like magnetized portions of the lower permanent magnet plate 11 and the upper permanent magnet plate 14. Are arranged as follows.
The sound radiating holes 14a provided in the upper permanent magnet plate 14 and the sound radiating holes 32a provided in the upper frame 32 are arranged at a constant interval along the neutral zone nz, like the meandering coil pattern 13b. ing.

  As described above, the tongue-like piece 13c provided on the vibration film 13 is not limited to the rectangular shape illustrated in FIG. 1 but may be formed in an elliptical shape or the like, and in a direction parallel to the film surface of the resin film 13a. That is, it extends from the edge part of the vibration film 13 by extending in the tangential direction of the resin film 13a. The tongue-like pieces 13c are provided at the four corners of the vibration film 13 as shown in FIG. If the tongue-like pieces 13c provided at the four corners of the vibration film 13 are sandwiched between the lower frame 31 and the upper frame 32, the vibration film 13 is supported / fixed inside the frame 3 so as not to adversely affect vibration. It becomes possible to do. The tongue-shaped piece 13c is not limited to being provided at the above four corners due to differences in the shape, size, material, and the like of the diaphragm, but the shape of the tongue-shaped piece, the position, quantity, and the meandering coil pattern 13b. It is not limited to what was illustrated here, such as a positional relationship. Since the tongue-shaped piece 13c affects the vibration of the vibration film 13, it is preferable that the contact area with the frame 3 and other members be made as small as possible. In the quadrilateral vibration film 13 illustrated here, If they are provided at the four corners, the influence on vibration is suppressed.

Next, assembly of the electromagnetic transducer will be described.
The lower permanent magnet plate 11 is stacked on the lower frame 31 of the ferromagnetic material so that the multipolar magnetization pattern of the lower permanent magnet plate 11 is exposed upward, and the magnetic force of the lower permanent magnet plate 11 is applied. To attach / fix. The buffer member 12a is placed on the surface of the lower permanent magnet plate 11 having the multipolar magnetization pattern, and the vibration film 13 is overlaid on the buffer member 12a. At this time, while observing the magnetization pattern of the lower permanent magnet plate 11 using a magnet viewer, the vibrating membrane 13 is moved to an appropriate position, that is, the multipolar magnetization pattern and the meandering coil pattern 13b are in the above-described positional relationship. To place.
The upper permanent magnet plate 14 is mounted inside the box-shaped upper frame 32 using the magnetic force of the magnet plate so that the multipolar magnetization pattern of the upper permanent magnet plate 14 is exposed downward. A buffer member 12b is disposed between the surface of the upper permanent magnet plate 14 having the multipolar magnetization pattern and the vibration film 13, so that the vibration film 13 is sandwiched between the lower permanent magnet plate 11 and the upper permanent magnet plate 14. The lower frame 31 and the upper frame 32 are overlapped, and, for example, the above-mentioned fitting portions are fitted and fixed. At this time, each tongue-like piece 13 c of the vibration film 13 is sandwiched between the upper frame 32 and the lower frame 31, and the vibration film 13 is supported / fixed inside the frame 3.

  In the example illustrated in FIG. 2, the length of the tongue-like piece 13 c is configured so as to reach the joining portion of the lower frame 31 and the upper frame 32 along the side surface of the lower permanent magnet plate 11. The shape piece 13c is sandwiched between the lower permanent magnet plate 11 and the upper frame 32. For example, the shape of the lower frame 31 is different from that illustrated in FIG. The upper frame 32 may be configured to fit the side frame 31, and the tongue-like piece 13 c may be sandwiched only at a portion where the upper frame 32 and the lower frame 31 are joined. Or you may comprise so that the tongue-like piece 13c may be pinched | interposed between the upper side permanent magnet plate 14 and the lower side frame 31. FIG.

FIG. 3 is a perspective view showing another configuration of the electromagnetic transducer according to the first embodiment. The same reference numerals are used for the same or corresponding parts as those shown in FIG. 1, and the description thereof is omitted. 3 is provided with a tongue-like piece 13d instead of the tongue-like piece 13c of the vibrating membrane 13 shown in FIG. The other parts are configured in the same manner as shown in FIG. 1, and therefore, a duplicate description of these parts is omitted here. The vibrating membrane 13 shown in FIG. 3 is provided with tongue-like pieces 13d extending in the longitudinal direction of a rectangular resin film 13a at four corners. The tongue-shaped piece 13 d is sandwiched between the lower frame 31 and the upper frame 32 in the same manner as the tongue-shaped piece 13 c described above, and the vibration film 13 is disposed / fixed inside the frame 3.
Even when configured in this way, the same effects as those of the electromagnetic transducer 1 shown in FIG. 1 and the like can be obtained. Compared to the case where the vibration membrane is fixed using a tape, Effects caused by variations in length, effects caused by differences in tape attachment position and tape contact area, and vibration caused by tape attached to the vibration film that occurs even when tape is applied to the vibration film accurately It is possible to eliminate the influence of hindering the tape and the influence of aging deterioration of the tape adhesive force.

  As described above, according to the first embodiment, the tongue-shaped piece 13c provided in the vibration film 13 is sandwiched between the lower frame 31 and the upper frame 32 so that the vibration film 13 is fixed to the frame 3. There is an effect that it is possible to obtain an electromagnetic transducer that suppresses individual differences and has stable performance.

It is a disassembled perspective view which shows the structure of the electromagnetic transducer by Embodiment 1 of this invention. 2 is an explanatory diagram illustrating a configuration of an electromagnetic transducer according to Embodiment 1. FIG. 6 is a perspective view showing another configuration of the electromagnetic transducer according to Embodiment 1. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Electromagnetic transducer, 2 structure, 3 frame, 11 lower permanent magnet plate, 12a, 12b shock absorbing member, 13 vibration film, 13a resin film, 13b meander coil pattern, 13c, 13d tongue-like piece, 14 upper permanent magnet plate , 14a, 32a Sound radiation hole, 31 lower frame, 32 upper frame.

Claims (3)

A permanent magnet plate having a plurality of belt-shaped magnetized portions, an oscillation film having a coil pattern for inputting an audio signal and electromagnetically coupled to the permanent magnet plate, and a frame surrounding the permanent magnet plate and the oscillation film In electromagnetic transducer,
The vibrating membrane is provided with a tongue-shaped piece protruding from an edge portion of the vibrating membrane,
An electromagnetic transducer, wherein the vibrating membrane is supported by sandwiching the tongue-like piece at a joint portion between the first frame and the second frame forming the frame.   2. The electromagnetic transducer according to claim 1, wherein a tongue-like piece of the vibration film is sandwiched between a permanent magnet plate attached to the first frame and the second frame.   The electromagnetic transducer according to claim 1, wherein the tongue pieces are provided at four corners of the vibration film formed in a quadrilateral shape.

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