JPH0217800A - Dynamic type electric/acoustic transducer - Google Patents

Abstract

PURPOSE:To efficiently collect a magnetic flux and to enhance sensitivity by forming a magnetic pole piece on the surface facing through a cylindrical magnetic cavity in the diameter direction to a field magnet for an oscillation force generating coil. CONSTITUTION:Two ring-shaped magnetic members 17 and 18 formed by a magnetic substance are overlapped in upper and lowe directions and a stator 20, the vertical cross section forms a U-shaped part 19, is constituted. The stator 20 has magnetic pieces 17a and 18a on the surface facing through toe magnetic cavity in the diameter direction to the outer peripheral surface of a field magnet 22. By these magnetic pieces 17a and 18a, a housing recessed part 23 of a coil 24 for generating oscillation force is formed. The field magnet 22 is supported reciprocatively freely in the shaft direction in a ring-shaped magnetic cavity 21.

Description

[Detailed Description of the Invention] [Industrial Application Field of the Invention] The present invention relates to an electrodynamic electroacoustic exchanger (electrodynamic electroacoustic device) such as a speaker, a microphone, an earphone, etc.
The feature is that the vibration force generating coil is fixed and the field magnet moves, which reduces the weight of the movable body, improving the response speed and suppressing the vibration. Increase the efficiency of converting sound or electric current.

Low-pitched fvI can be generated easily, and since there is no need to drag the lead wire, you can expect it to last a long time.

It simplified IT construction and allowed mass production at low cost.

The reason is that it is an efficient electroacoustic exchanger.

[Technical background and problems] Electrodynamic electroacoustic exchanger 2 For example, in a speaker, the voice coil is movably placed in a magnetic field and when a sound current is applied, the voice coil vibrates as the current changes. It is something. In this case, a speaker that reproduces sound waves by moving a vibrating body with a coil is called a dynamic speaker, and a speaker that emits sound waves by directly connecting a coil to a cone-shaped paper or the like is called a dynamic cone speaker. A dynamic horn speaker is one in which a small vibrating body is moved by a voice coil, and a horn (or trumpet) is attached to the front of the vibrating body to efficiently emit sound waves.

These electrodynamic electroacoustic exchangers all have similar M
3'M, the speaker will be explained below.

Many conventional dynamic cone speakers 1 are constructed as shown in FIG.

That is, a permanent magnet 4 made of a cylindrical ferrite magnet is attached to a yoke plate 3 having a center ball (center magnetic pole) 2. A similarly cylindrical upper yoke plate 5 is disposed and fixed with an adhesive or the like to form a field section 6, thereby forming a fixed side. The field section 6 shown here is called an external magnet type, but it may also be an internal magnet type that uses a yoke and incorporates a columnar permanent magnet and a center ball in the center of the inside of the yoke. good.

A cone-shaped frame 7 is coupled to this field section 6.
The peripheral edge of a cone-shaped vibrating body 9 is bonded to the peripheral edge of the frame 7 together with a gasket (satellite) 8 using an adhesive or the like. At the center of the vibrating body 9 is a coil bobbin 1 made of paper, thin plastic, etc., in which a cylindrical voice coil 10 is wound around the lower part of the vibrating body 9.
1 are combined.

The middle part of the coil bobbin 11 holds the voice coil 10 at the center between the magnetic poles and performs appropriate damping (braking) on vibrations.
The voice coil 10 is supported by a damper 12 for applying pressure, so that the voice coil 10 is correctly positioned within the magnetic gap 13 of the field section 6. Further, a dust cap 14 such as a dustproof cloth is attached to the upper surface of the central portion of the vibrating body 9 to prevent dust in the air from entering the annular magnetic gap 13.

According to such a conventional speaker 1, the voice coil 1
0 drags the lead wire and vibrates, and if used for a long time, the lead wire may break or the solder may come off, leading to breakage, and the service life may be shortened. Ta.

In addition, both terminals of the lead wire (not shown) of the voice coil 10 are pulled out from the top through the magnetic gap ]3, and
Since it is guided to the vibrating body 9 (or it may be the frame 7) and soldered at that position, ■ Magnetic gap 1
By using the voice coil 10 with a limited thickness in order to pass both terminals of the lead wire of the voice coil 10 inside the magnetic gap 13, the magnetic flux density within the magnetic gap 13 cannot be increased by the thickness of the lead wire. It was becoming inefficient.

■ Since both terminals of the lead wire of the voice coil 10 must be passed through the magnetic gap 13, and both terminals of this lead wire must be soldered to the vibrating body 9, etc., it is not suitable for mass production and is expensive. It had become. ■ Also, the vibrating body 9 is
When the vibrating body 9 is made of the thin film plastic of today, if the terminal of the lead wire is soldered to it, the heat generated at the time will cause holes to form, resulting in a high defect rate. could not be mass-produced. ■
In addition, since both terminals of the lead wire of the voice coil 10 are passed through the magnetic gap 13, there is a risk that the lead wire may come into contact with the fixed side when the voice coil 10 vibrates, so it must be manufactured with great precision. The defect rate was also very high.

In addition, in the case of the conventional speaker 1, since the voice coil 10 vibrates, ■ The conducting wire that makes up the voice coil 10 has a heavy specific gravity (the specific gravity of copper is approximately 7), so the load is large, and the response speed is low. This method has the disadvantage that it is slow and cannot extract audio signals with high precision over a wide range. In particular, it wasn't good enough to extract dynamic bass. ■ Also, in order to eliminate the drawback of ■ above due to the extremely heavy conductor wire for forming the voice coil 1, i.e., voice coil 1.
In order to prevent the weight of the wire from becoming heavy and to widen the magnetic gap 13 so as not to reduce the magnetic flux density in the magnetic gap 13, the conducting wires are placed closely together so as not to overlap.
The winding must be formed in a close-winding manner in a row (also called aligned winding).Manufacturing the winding of the voice coil 10 tightly wound in a single row in this way requires extremely high precision and is difficult. However, it had the disadvantage of having a high defect rate and being extremely expensive. (1) One of the causes of the above-mentioned drawbacks (2) and (2) is that the resistance value of the voice coil 10 is set as 1, for example, 8Ω, according to the standards of the conventional loudspeaker 1 and the like. However, manufacturing the voice coil 10 according to the resistance value is extremely troublesome and has the disadvantage of not being suitable for mass production.

In addition, as described above, the voice coil 10 must be formed by tightly winding it in one row, which makes it impossible to wind the conductive wire in multiple turns, which results in the generation of a large driving force to vibrate the voice coil 10. Therefore, in the case of low-pitched sounds, it was not possible to output audio signals with high accuracy. Also,
In particular, when trying to produce bass sounds with high precision, the precision becomes extremely high.

It has not been possible to produce a speaker or the like that can produce accurate bass sounds at low cost.

Note that the driving force T for vibrating the voice coil 10 is as follows.

T = t-1 t: Number of turns of the conductor I: Given by the current, but conventionally, the number of winding turns t of the conductor cannot be made to a large value due to the above reasons, so a large driving force is required as described above. Not only can you not get
This has the drawback that the value of the current I also becomes large, resulting in an inefficient speaker l.

[Problem of the Invention] An object of the present invention is to completely change the concept of conventional electrodynamic electroacoustic exchangers and move the field magnet without moving the coil, so that the coil does not drag the lead wire. The objective of this project was to provide an electrodynamic electroacoustic exchanger that would have a long life and high reliability by eliminating breakage of lead wires due to vibration and damage due to solder coming off.

In particular, in an electrodynamic electroacoustic exchanger configured to achieve such a problem, the magnetic force of a small field magnet is used to make the magnetic force of a small field magnet small enough to wait for a high-performance bass acoustic signal. The objective of this project was to obtain a high-performance electrodynamic electroacoustic exchanger that could be used in a variety of ways.

Although there are some common items to achieve such problems, in addition to these, there are also problems obtained by items unique to the embodiments, and these problems will be explained below.

Another challenge is to be able to efficiently collect the magnetic flux density of the field magnet.

And in order to accomplish these tasks.

In order to concentrate the magnetic flux density of the field magnet, the present invention provides magnetic pole pieces that can alternately form N-pole and S-pole as shown below. The object of the present invention is to make effective use of the magnetic pole pieces to effectively house the vibration force generating coil.

That is, a vibration force generating coil storage part is formed of a magnetic material so that the coils can be held, and the coils are separated from each other in the axial direction and have different polarities in the coil storage holding part. By forming a plurality of magnetic pole pieces that can efficiently collect the magnetic flux density of the field magnet on the plurality of magnetic pole pieces, and switching the energization to the vibration force generation coil provided in the coil storage and holding part, the plurality of magnetic pole pieces can be N on the pole piece
An actuator that forms magnetic poles such as poles or south poles, generates large attractive and repulsive forces, and generates a large vibration force of the field magnet, and can generate acoustic signals with good vibration response, that is, with high precision. The objective was to make it possible to mass-produce electroacoustic exchangers in a small size and at low cost.

Also, there is no need to pass the lead wire through the magnetic gap between the field magnet and the vibration force generating coil.

It is something that was given.

Another problem of the present invention is that by configuring the coil so that it does not move, the lead wire does not come into sliding contact with the fixed side.
Moreover, by constructing the field magnet using a magnetic material with a specific gravity smaller than that of the conducting wire forming the coil (for example, one with a specific gravity of 4 to 6), and making it move,
By reducing the weight of the transducer and increasing its response speed, we have made it possible to extract audio signals over a wide range with greater accuracy, and in particular, to be able to construct a device that can extract dynamic bass sounds at a low cost. This was done with the goal of making it possible.

In this way, as a field magnet, a magnetic material with a specific gravity smaller than that of the conducting wire forming the coil (for example, a specific gravity of 4 to 6
The objects of the present invention can be achieved by using an appropriate radially anisotropic rare earth-based or neodymium-iron-boron-based magnet material that can obtain a strong magnetic flux even when constructed using ing.

In addition, by creating a configuration that does not require moving the coil,
The conductor wires, which are very difficult to manufacture, should be placed closely together so that they do not overlap.
By making it possible to use flat winding, which eliminates the need for the close winding method of winding wires in rows (also called aligned winding), it is extremely easy to manufacture a single winding, reducing the defective rate and making the vibration force generating coil cheaper. And by making it easy to mass produce.

The objective was to mass produce electrodynamic electroacoustic exchangers of constant quality at low cost.

In addition, if the purpose is to obtain an extremely large vibration force according to certain specifications, the structure should be such that there is enough space to accommodate a coil wound with many turns. so that it does not have to form,
To extract accurate low-pitched audio signals even in the case of low-pitched sounds by using a coil formed by winding many turns of a conducting wire to generate a large driving force for vibrating the field magnet. This was done with the goal of making it possible to do so.

By doing this, the driving force for vibrating the field magnet T T = t・I t: Number of turns of the conductor ■ 2 i In the current, the number of winding turns t of the conductor is formed to a large value. By doing so, it is possible to obtain a large driving force T, and also electric power! The object of this invention is to make it possible to obtain an efficient electrodynamic electroacoustic exchanger such as a speaker by reducing the value of I.

The object of the present invention is to provide a cylindrical single-pole field magnet whose inner and outer surfaces are magnetized with different polarities so that it can move freely in the axial direction within the palanquin-shaped magnetic gap of the magnetic circuit, and to On the fixed side facing the side surface of the magnet with a gap in the radial direction, a ring-shaped vibration force generating coil housing recess is provided at both upper and lower ends in the axial direction, each of which has magnetic pole pieces that are separated from each other and can form a different shape. 1. A vibrating body that is provided with a magnetic body having a magnetic body, and a vibrating force generating coil formed in a ring shape is housed and fixed in a vibrating force generating coil housing recess of the magnetic body, and is interlocked or brought into contact with the vibration movement in the axial direction of the field magnet. This is achieved by providing an electrodynamic electroacoustic exchanger that is installed directly or at a distance from the field magnet.

[Embodiment of the present invention] [First embodiment of the invention] Figure 1 shows the dynamic cone speed 15 of the present invention.
FIG. 2 is an exploded perspective view with a part thereof cut away, and FIG. 2 is a longitudinal sectional view thereof. A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A dynamic cone speaker 15 showing a first embodiment of the present invention is constructed so that the magnetic circuit 16 can be formed very thin in the axial direction, and therefore can be constructed very flat and lightweight. ing.

The magnetic circuit 16 includes two ring-shaped magnetic members 17 and 18 made of one magnetic material, stacked one above the other to form a stator 20 made of a magnetic material and having a U-shaped section 19 in longitudinal section.

This stator 20 consists of a cylindrical unipolar field magnet 22 whose inner and outer surfaces are magnetized with different polarities so as to be movable in the axial direction within the yA-shaped magnetic gap 21. void 2
They are separated from each other at both upper and lower ends in the axial direction so that different poles can be formed on the sides of the stator 20 facing each other via the magnetic gap 21. (It means "on the surface facing the magnetic magnet 22," and the expression "separation" will be used in this sense in similar embodiments below.) Magnetic pole piece 17
a, forming 18a. By forming the magnetic pole pieces 17a and 18a on the stator 20 body, the field magnet 22
A vibration force generating coil accommodating recess 23 formed by a U-shaped vertical section 19 is formed on the stator 20 side facing the outer circumferential surface of the stator 20 with a radial magnetic gap 21 interposed therebetween. A vibration force generating coil 2 formed in a ring shape in a vibration force generating coil housing recess 23 formed by the U-shaped portion 19 made of the magnetic material.
4 is stored and fixed. The lead wire 25 of the vibration force generating coil 24 is connected to the magnetic member 18 forming the U-shaped portion 19.
It is led to an external circuit through a through hole 26 formed in the. The inner surface of the stator 20 and the magnetic gap 21 in the radial direction must be formed to have a width of 22 mm using an optimal magnetic material and an appropriate forming method. Here,! & A suitable magnetic material for forming the field magnet 22 is one in which the field magnet 22 is lighter than the specific gravity of the vibration force generating coil 24, has a strong magnetic flux density, and is extremely easy to process or form. For this reason, the field magnet 22 selected and prototyped by the inventor of the present invention is made of a rare earth material of about 4 to 6 or neodymium.
Using a boron/iron based (may be made of materials other than the above three types of components) resin magnet (of course, a sintered type magnet may be used), the magnet may be molded by appropriate means such as injection molding means. A cylindrical shape is used. In this embodiment, the field magnet 22 is magnetized into a single pole so that the inner and outer peripheries have different polarities.

It is a single-pole type with the inner circumference magnetized to the S pole and the outer circumference magnetized to the N pole. A cone-shaped frame 27 is fixed to the upper part of the stator 20.

The peripheral edge of a cone-shaped vibrating body 28 is coupled to the upper peripheral edge of the frame 27 with a gasket (not shown) by adhesive or the like. The lower end cylindrical portion 28 of this vibrating body 28
The field magnet 22 is coupled to a, and the magnetic air gap 2
1, reciprocating vibrations can be made in the axial direction.

Between the frame 27 and the cylindrical part 28a, the field magnet 22 is held at the center of the magnetic pole and supported by a damper 29 for applying appropriate damping (braking) to vibrations. The vibrating body 28 is positioned correctly within the magnetic gap 21 of the magnetic circuit 16).The upper surface of the central portion of the vibrating body 28 is covered with dustproof cloth or the like to prevent dust in the air from entering the magnetic gap 21. Cap 30 is attached.

[Second Embodiment of the Invention] FIG. 3 shows a dynamic cone speaker 31 of the present invention.
FIG. A second embodiment of the present invention will be described below with reference to FIG. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

A dynamic speaker 31 according to a second embodiment of the present invention is the same as the speaker 15 according to the first embodiment, but has an inner surface of the field magnet 22 and a minute annular magnetic gap 32 in the radial direction.
A center ball 33 having a cylindrical shape in longitudinal section is provided through the magnetic circuit 34 to almost completely close the magnetic path in the magnetic circuit 34, thereby obtaining a larger vibration force.

The center ball 33 made of a magnetic material is constructed by integrally forming a cylindrical magnetic material perpendicular to the inner circumference of a flat ring-shaped magnetic material 35 fixed to the lower part of the magnetic material 18.

In the speaker 31 of the second embodiment, a center ball 33 is provided on the inner periphery of the field magnet 22 to completely close the magnetic path, so vibrations are larger than that of the speaker 15 of the first embodiment. Although a force is generated, depending on certain specifications, the generated sound may be somewhat distorted, so it is necessary to optimally design the components of the speaker 31 in consideration of specifications, cost, etc.

[Third Embodiment of the Invention] Both the speakers 15 and 31 of the first and second embodiments have an outer periphery drive type structure, but in this third embodiment, an inner periphery drive type structure is used with reference to FIG. The dynamic cone speaker 36 will be explained. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

A dynamic cone speaker 36 showing a third embodiment of the present invention has a magnetic circuit 37 that is very thin in the axial direction and has a small outer diameter and can be formed compactly, and is therefore very flat, small and lightweight. drawing things.

The magnetic circuit 37 includes a field magnet 22 and a magnetic material fixed to a cup-shaped stator 40 made of a non-magnetic material via the inner periphery of the field magnet 22 and a fine radial annular magnetic gap 39. It is mainly formed by the formed ring-shaped magnetic member 38. The ring-shaped magnetic member 38 is formed to have a U-shaped portion 41 in a longitudinal section, and a field is supported on the outer periphery of the U-shaped portion 41 so as to be movable in the axial direction within the annular magnetic gap 39. Magnetic pole pieces 38a, 38 which are separated from each other and can form different poles are provided at both upper and lower ends in the axial direction facing the inner circumferential surface of the magnet 22 via a radial magnetic gap 39.
It forms b. By forming the magnetic pole pieces 38a and 38b, a vibration force generating coil housing recess with a U-shaped longitudinal section is formed in the ring-shaped magnetic body 38 via the □ inner peripheral surface of the field magnet 22 and the radial magnetic gap 39. '42. A ring-shaped vibrating force generating coil 24 is housed and fixed in the four vibrating force generating coil storage parts 42. A lead wire (not shown) of the vibration force generating coil 24 is led to an external circuit via a through hole (not shown) formed in the stator 40 or the like.

Stator 40 is fixed to frame 27 by appropriate means. The stator 40 may be formed integrally with the frame 27. If the stator 40 is made of a magnetic material, the stator 40 may be formed integrally with the frame 27. Side surface 4 of cup-shaped stator 40
0a can also function as a five-back yoke for closing the magnetic path of the field magnet 22.

[Fourth embodiment of the invention] FIG. 5 shows a dynamic cone speaker 44 of the invention.
FIG. 6 is an exploded perspective view with a part thereof cut away, and FIG. 6 is a longitudinal sectional view of the same. A fourth embodiment of the present invention will be described below with reference to FIGS. 5 and 6. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

In a dynamic cone speaker 44 showing a fourth embodiment of the present invention, a magnetic circuit 45 has two magnetic circuits in the speaker 15.
Two ring-shaped magnetic members 17 and 18 magnetic pole pieces 17a, 18
It can be said that the structure is such that each of the coils a is slightly bent and extended on the side of the vibration force generating coil 24 facing the field magnet 22.

Referring to FIGS. 5 and 6, the magnetic circuit 45 is made of a magnetic material in which two ring-shaped magnetic members 46 and 47 formed of a magnetic material are stacked vertically to form a U-shaped portion 48 in longitudinal section. This constitutes the finished stator 49. The four stators are separated from each other on the side of the stator 49 that faces the outer peripheral surface of the field magnet 22 supported movably in the axial direction within the annular magnetic gap 50 via the magnetic gap 50 in the radial direction. Magnetic pole pieces 46a and 47a are formed at both upper and lower ends in the axial direction, respectively, so that poles can be formed.

The magnetic pole pieces 46a and 47a are respectively connected to the field magnet 2.
A part of the side facing 2 is further bent and extended inward in the axial direction, and bent to cover a part facing the vibration force generating coil 24 which faces the field magnet 22 through the magnetic gap 50. Extension parts 46b and 47b are formed.

In this way, the magnetic pole piece 46a of the stator 49, which faces the outer circumferential surface of the field magnet 22 via the radial magnetic gap 50,
By configuring the area of 47a to be large.

This allows for greater vibration force and more accurate acoustic signals to be obtained. By forming the magnetic pole pieces 38a and 38b, a magnetic gap 50 is formed between the outer peripheral surface of the field magnet 22 and the radial direction.
On the inner surface of the stator 49 formed by the ring-shaped magnetic bodies 46 and 47, four ring-shaped vibration force generating coil storage parts 51 having a U-shaped vertical section 48 are formed. A ring-shaped vibration force generation coil 24 is housed and fixed in the four vibration force generation coil storage parts 51. A lead wire (not shown) of the vibration force generating coil 24 is led to an external circuit via a through hole (not shown) formed in the ring-shaped magnetic member 47 or the like. The inner surface of the stator 49 and the radial magnetic gap 50
The cylindrical field magnet 22 is connected to the annular magnetic gap 5 through the annular magnetic gap 5.
0 is arranged so that it can freely reciprocate in the axial direction. Stator 49
is fixed to the lower end of the frame 27 with a screw 52, but this is because the prototype was drawn by chance in the drawings, and there is no need to employ such means during mass production.

[Fifth embodiment of the invention] FIG. 7 shows a dynamic cone speaker 53 of the invention.
FIG. A fifth embodiment of the present invention will be described below with reference to FIG. Note that the same reference numerals are given to the same parts as in the fourth embodiment, and the explanation thereof will be omitted.

A dynamic cone speaker 53 showing a fifth embodiment of the present invention has a magnetic circuit 45 of the speaker 44 of the fourth embodiment.
In this case, a center pole 56 having a cylindrical shape in longitudinal section is provided between the inner surface of the field magnet 22 and a fine annular magnetic gap 55 in the radial direction, so that the magnetic path in the magnetic circuit 54 is almost completely closed. to obtain greater vibrational force. Center ball 5 made of magnetic material
6 is constructed by integrally forming a cylindrical magnetic body perpendicular to the inner circumference of a flat ring-shaped magnetic body 57 fixed to the lower part of the stator 49.

[Sixth Embodiment of the Invention] Both the speakers 44 and 53 of the fourth and fifth embodiments have an outer periphery drive type structure, but in this sixth embodiment, an inner periphery drive type structure is used with reference to FIG. The dynamic cone speaker 58 will be explained. Note that parts that are common to those in the above embodiment are denoted by the same reference numerals, and explanation thereof will be omitted.

In the dynamic con speaker 58 showing the sixth embodiment of the present invention, the magnetic circuit 59 can be formed to be very thin in the axial direction and small in outer diameter, and therefore can be configured to be extremely flat, small and lightweight. It depicts something structured like this.

Magnetic diagram F1859 shows the field magnet 22, the inner circumference of the field magnet 22, and the minute annular magnetic gap 6 in the radial direction.
A ring-shaped magnetic member 6 made of a magnetic material is fixed to the upper part of a cup-shaped stator 61 made of a non-magnetic material through
It is mainly formed by 2. The ring-shaped magnetic member 62 is
It is formed to have a U-shaped portion 63 in the longitudinal section, and the inner circumferential surface of the field magnet 22 supported so as to be movable in the axial direction within the annular magnetic gap 60 is formed on the outer periphery of the U-shaped portion 63. Radial magnetic sky Ilj! Magnetic pole pieces 62a and 62b which are separated from each other and can form different poles are formed at the upper and lower ends in the axial direction that face each other via the magnetic pole piece 60.

By forming the magnetic pole pieces 62a and 62b, a vibration force generating coil with a vertical cross-section shape is attached to the ring-shaped magnetic body 62 via the inner peripheral surface of the field magnet 22 and the radial magnetic gap 60. A storage recess 64 is formed. A vibration force generation coil 2 formed in a ring shape in the vibration force generation coil storage recess 64
4 is stored and fixed. A lead wire (not shown) of the vibration force generating coil 24 is led to an external circuit through a through hole (not shown) formed in the stator 61 or the like.

Stator 61 is fixed to frame 27 by any suitable means. The stator 61 may be formed integrally with the frame 27. If the stator 61 is made of a magnetic material, the stator 61 may be formed integrally with the frame 27. Side surface 6 of cup-shaped stator 61
1a can also function as a back yoke for closing the magnetic path of the field magnet 22.

15. At 31, 36, 44, 53 and 58, when an alternating current of a magnitude based on the acoustic signal is passed through the vibration force generating coil 24, two magnetic pole pieces 17a formed separated from each other in the axial direction and 18a, 38a and 38b, 4
6a and 47a.

62a and 62b have N and S poles so that they are different from each other.
Since magnetic poles are formed, the magnetic poles generated in these magnetic pole pieces and the field magnet 22 repeat attraction and repulsion.
Since the field magnet 22 generates a force that causes the field magnet 22 to reciprocate along the axial direction of the magnetic gaps 21, 42, 50° 60, the field magnet 22 vibrates in the magnetic gaps 21, 42, 50, 60.
0 along its axial direction. For this reason.

The vibrating body 28 fixed to the field magnet 22 vibrates back and forth to generate an acoustic signal sound of an appropriate wavelength and magnitude.

[Action of the invention]
[Effects of the Invention] In the embodiments of the present invention, the principle of operation is as follows: As is clear from the above structure, both vibrations are the same, so to summarize, the speaker generating coil has a field magnet and a diameter Since the magnetic pole pieces are formed on opposing surfaces with a cylindrical magnetic gap in the axial direction, magnetic flux can be efficiently collected, and two magnetic pole pieces separated from each other in the axial direction have different polarities. Because of this, it is possible to generate a large vibration force and cause the field magnet to vibrate back and forth with good responsiveness, making it possible to obtain an electrodynamic electroacoustic exchanger that can generate or receive highly sensitive acoustic signals. be. In addition, there is no need to use a voice coil, which is difficult to manufacture and effective as in the past, and because the voice coil does not move and the field magnet moves, there is no lead caused by dragging the lead wire and vibrating. It is possible to obtain a highly reliable electrodynamic electroacoustic exchanger that is free from damage due to wire cutting or soldering and has a long life. Furthermore, since the troublesome process of soldering both terminals of the lead wire of the vibration force generating coil to the vibrating body or the like can be omitted, mass productivity is excellent and manufacturing is possible at low cost.

Furthermore, since the lead wire terminals do not need to be soldered to the vibrating body, the vibrating body can be easily mass-produced at low cost using a desirable thin film plastic. In addition, the field magnet (for example, specific gravity 4 to 6) has a lighter specific gravity than the conductor wire (specific gravity 7), and by constructing it with a magnetic material that can strengthen the magnetic force, the weight of the vibrator can be reduced and the response speed can be increased. This has been difficult in the past because it is faster and allows audio signals to be extracted over a wider range with higher precision. In particular, it has the effect of being able to construct a highly efficient device that can extract dynamic bass acoustic signals at low cost. Furthermore, a large amount of storage space can be obtained for the coil for generating sufficient vibration force.

Since the coil does not need to be moved, it is not necessary to use the conventional close winding method in which the conductor wires are closely wound in a single row to avoid overlapping, which is extremely difficult to manufacture. Since winding can be adopted, it is possible to extremely easily manufacture the winding of the power generating coil, reduce the defective rate, and make it possible to mass-produce the vibration force generating coil at low cost and easily. Yet again. A field magnet is made of Madai-t material that can generate strong magnetic force even if it is thin (especially recent technology has made this possible), and a ring-shaped vibration force generating coil is wound with a large number of turns. Therefore, it is possible to generate a large driving force to vibrate the field magnet by using the vibration force generating coil formed by winding a conductor wire with many turns, thereby generating low-pitched sounds. Even in the case of acoustic signals, there is an effect that highly accurate audio signals can be extracted.

Also, if you want to obtain a particularly large vibration force, the driving force to vibrate the field magnet is TT = t・I t: Number of turns in the conductor: In terms of current, the number of turns t in the conductor can be made to a large value. ,
Since a large driving force T can be obtained and the value of electric fiI can also be made small, there is an effect that an efficient electrodynamic electroacoustic exchanger such as a speaker can be obtained. Although the embodiments of the present invention have mainly been described with respect to speakers, the present invention is naturally applicable to other electrodynamic electroacoustic exchangers such as microphones having a common structural principle.

[Brief explanation of drawings]

FIG. 1 shows a dynamic cone according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the speaker, and FIG. 7 is a longitudinal sectional view of the dynamic cone speaker according to the second and third embodiments of the present invention, respectively. , FIG. 5 is an exploded perspective view of the main part of the dynamic cone bias force according to the fourth embodiment of the present invention, and FIG. 6 is a vertical cross-sectional view of the same, and FIGS. FIG. 9 is a vertical cross-sectional view of a conventional dynamic cone speaker. [Explanation of symbols] l: Dynamic cone speaker. 2...Center ball (center magnetic pole). 3...Center ball, 4...Permanent magnet. 5... Upper yoke plate, 6... Field section. 7...Frame 8...Gasket (arrow paper), 9...Vibrating body. 10... Voice coil 11... Coil bobbin, 12... Damper 13...
magnetic air gap. 14...Dust cap. 15...Dynamic cone speaker. 16... Magnetic circuit, 17... Ring-shaped magnetic member, 1
7a... Magnetic pole piece, 18... Ring-shaped magnetic member, 18
a... Magnetic pole piece, 19... U-shaped part, 20... Stator, 21... Annular magnetic gap, 22... Field magnet, 23... Coil storage part for generating vibration force , 24...
Vibration force generation coil, 25...Lead wire, 26...
Through hole. 27... Frame, 28... Vibrating body. 28a... Cylindrical part, 29... Damper 30... Dust cap, 31... Dynamic cone speaker, 32... Annular magnetic gap, 33... Center ball, 34... Magnetic circuit , 35...Flat ring-shaped magnetic material. 36...Dynamic cone speaker 237...
- Magnetic circuit, 38... ring-shaped magnetic member, 38a, 3
8b...Magnetic pole piece, 39...Annular magnetic gap, 40...
・Stator, 40a... Side, 41... ・U-shaped part, 4
2... Coil for generating vibration force, 43... Annular magnetic gap, 44 Dynamic cone speaker, 45... Magnetic circuit, 46.47... Ring-shaped magnetic member 4 (, a
47a...Magnetic pole piece, 48...U-shaped portion, 49...
- Stator, 50... Annular magnetic gap, 51... Coil housing section for generating vibration force. 52... Screw, 53... Dynamic con speaker, 54... Magnetic circuit, 55... Annular magnetic gap,
56...Center ball. 57...Flat ring-shaped magnetic material, 58...Dynamic cone speaker 59...Magnetic circuit, 60...
- Annular magnetic gap, 61... Stator, 61a... Side surface, 62... Ring-shaped magnetic member, 62a, 62b...
Magnetic pole piece, 63... U-shaped part, 64... Coil storage part for generating vibration force, 65... Annular magnetic gap.

Claims (3)

[Claims] (1) A cylindrical unipolar field magnet whose inner and outer surfaces are magnetized with different polarities so that it can move freely in the axial direction within the cylindrical magnetic gap of the magnetic circuit is provided, and the side surface of the field magnet A magnetic device having a ring-shaped vibration force generating coil storage recess formed with a plurality of magnetic pole pieces that are separated from each other in the axial direction and can form different poles on fixed sides facing each other through a radial magnetic gap. A vibration force generating coil formed in a ring shape is housed and fixed in a vibration force generating coil storage recess of the magnetic body, and the vibrating body is interlocked with or in contact with the vibration movement of the field magnet in the axial direction. An electrodynamic electroacoustic exchanger that is installed directly or at intervals on a field magnet. (2) The magnetic pole pieces formed at both the upper and lower ends in the axial direction of the magnetic body are formed so as to extend slightly to the vibrating force generating coil surface facing the field magnet. The electrodynamic electroacoustic exchanger described in . (3) The field magnet is formed of an anisotropic magnetic material oriented in the radial direction, and is formed of a magnetic material having a specific gravity lighter than the vibration force generating coil. ) or (2).