JPH06113395A - Electroacoustic transducer - Google Patents

Abstract

PURPOSE:To provide the electroacoustic transducer in which an iron core being a separate member is formed of a base member and a base part is simplified by making a hybrid configuration of base members. CONSTITUTION:The electroacoustic transducer is the one in which a diaphragm 30 and a magnetic drive section 5 receiving an electric signal and vibrating the diaphragm magnetically are built in an outer case 2 and provided with a base member metal base 40 formed of a magnetic material and whose one side is integrally formed with an iron core 60 to clog an opening of the outer case, and terminal conductor patterns 50, 52 formed on an insulation film 48 formed on the other side of the base member and to which lead section of a coil 20 wound on the iron core are connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroacoustic transducer for converting an input electric signal into sound.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic electroacoustic transducer is shown in FIG.
Further, as shown in FIG. 7, a cylindrical outer case 2 formed of synthetic resin is provided, and a base portion 4 is installed on the opening side of the outer case 2. The base portion 4 is a closing means that closes the opening of the outer case 2 and a portion that functions as a support member for the magnetic drive portion 5. The iron core 6, the base 8, the substrate 10, and the terminal 1 are provided.
2, 14 and caulking pins 16 and 18 are composed of 7 parts of 5 types. That is, the substrate 10 and the base 8 are fixed by caulking the rear portion of the iron core 6. The base portion 4 has a double structure including the substrate 10 and the base 8, and the substrate 10 is provided with the crimping pins 16 and 18 on the terminal 1.
2 and 14 are fixed.

The iron core 6 constitutes a part of the magnetic drive unit 5, around which a coil 20 is wound, and its lead portions 22 and 24 are individually connected to the terminals 12 and 14. An annular magnet 26 fixed to the base 8 is installed around the coil 20.

Further, in this electroacoustic transducer, a step portion 27 is provided inside the outer case 2 so that the front side has a small diameter and the rear side has a large diameter, and is supported between the step portion 27 and the base 8. A space retaining ring 28 as a member is installed. A vibration plate 30 that converts magnetic vibrations into mechanical vibrations is installed on a seating surface formed on the inner peripheral portion of the spacing ring 28. The vibrating plate 30 is installed with a gap 32 between the vibrating plate 30 and the end surface of the iron core 6 to allow mechanical vibration.
A magnetic piece 34 is fixed to the diaphragm 30, and a resonance space 36 for causing resonance vibration is provided inside the exterior case 2 on the front side thereof. A cylindrical sound emission hole 38 that opens the resonance space 36 to the outside air is formed on the front surface side of the outer case 2.

Therefore, in such an electroacoustic transducer, when an electric signal of an appropriate level is applied to the terminals 12 and 14, the coil 20 is excited by the electric signal,
The vibration causes the diaphragm 30 to vibrate vertically in the drawing. The vibration of the diaphragm 30 depends on the amplitude and frequency of the applied electric signal. As a result, the sound generated by the vibration of the diaphragm 30 is emitted to the outside air from the sound emitting hole 38 while being accompanied by the resonance vibration of the resonance space 36. In this case, the base portion 4 also has a function of keeping airtightness from the back surface side of the diaphragm 30, and contributes to a certain acoustic characteristic in generating sound.

[0006]

By the way, in such an electroacoustic transducer, the base portion 4 in the outer case 2 is used.
Is a very large proportion, which hinders its size and weight reduction. Conventionally, for downsizing and weight reduction,
Although the iron core 6 has been shortened, such a method affects the number of windings of the coil 20 and the winding form, and the flattening of the electroacoustic transducer lowers the generated magnetic field, that is, the magnetic drive. There is a drawback that the force is lowered and the sound pressure is lowered.

Further, reducing the resonance space 36 that occupies a large volume in the outer case 2 is effective for downsizing the electroacoustic transducer. The resonance space 36 plays an important resonance effect in generating sound. Therefore, the narrowing thereof deteriorates the resonance effect and has a bad influence on the acoustic characteristics far more than the reduction of the magnetic driving force, which is not a good idea.

The iron core 6 includes a base 8 and a substrate 10.
It is erected by piercing it and staking its rear end. That is, in this electroacoustic transducer, the base 8 and the substrate 1
It forms a fixing means that integrates 0 and 0, and is configured as a separate member from the base 8. Moreover, in order to perform the function as such a fixing means, the step portion 11 is provided in the middle portion.
Is provided to form the small diameter portion 13 on the rear end side, and the small diameter portion 13 requires a length obtained by adding a crimping length to the thickness of the base 8 and the substrate 10 for crimping.

Therefore, the use of the iron core 6 has the following drawbacks. Firstly, since it is a fixing means for the base 8 and the substrate 10, the iron core 6 becomes long, and moreover, caulking processing is required and the processing cost becomes high. Secondly, since the iron core 6 is a separate member, the number of parts increases accordingly. Thirdly, the caulking process forms a head portion by caulking at the rear end portion of the iron core 6, and in an electroacoustic transducer having a major axis of 10 mm and a height of 8 mm, the ratio is large. This causes a loss of miniaturization of the converter. For example, the outer case 2 needs to be large in order to cover the head. Fourth
In addition, the base 8 together with the iron core 6 is formed of a ferromagnetic material and forms a part of the magnetic circuit of the magnetic drive unit 5. However, when the iron core 6 and the base 8 are mechanically coupled, The effect of the joint is to affect the magnetic characteristics and thus the acoustic characteristics.

Therefore, an object of the present invention is to provide an electroacoustic transducer in which an iron core, which is a separate member, is formed of a base member and simplification is realized by hybridizing the base portion.

[0011]

The electroacoustic transducer of the present invention, as illustrated in FIGS. 1 and 2, together with a diaphragm (30), magnetically vibrates the diaphragm by receiving an electric signal. An electroacoustic transducer having a magnetic drive unit (5) built in an outer case (2), which is formed of a magnetic material, and an iron core portion (60) is integrally formed on one surface side by molding the magnetic material (5). A coil (20) formed on the base member (metal base substrate 40) that closes the opening of the outer case and the insulating film (48) formed on the other surface of the base member and wound around the iron core portion. ) Lead part (22,2)
4) terminal patterns to be connected (conductive patterns 50, 5
2) and are provided.

[0012]

In the electroacoustic transducer of the present invention, the base member is formed of a magnetic material, the iron core portion is integrally formed on one surface side of the base member by molding, and the insulating film is formed on the other surface side. The terminal pattern is formed on the top. A coil is wound around the iron core portion to have a structure required for the magnetic drive unit.
The lead portion of the coil is connected to the conductive pattern of the base member and is drawn to the outside. With this structure, the base member is integrated with the iron core part and hybridized, the number of parts is reduced, the electroacoustic transducer is flattened, and the magnetic properties are improved by the integration with the iron core part. It is.

Further, such simplification of the base member contributes to the effect of suppressing unnecessary vibration and also contributes to the improvement of acoustic characteristics.

[0014]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

1 and 2 show one embodiment of the electroacoustic transducer of the present invention. In this electroacoustic transducer, a single metal base substrate 40 is used for the base portion 4 as a plate-shaped base member formed of a magnetic material. The metal base substrate 40 is formed with a closing portion 42 that closes an opening on the back surface side of the outer case 2 and a terminal portion 44 that is formed by extending a part of the closing portion 42 in the diametrical direction. The terminal portion 44 is formed with a bent portion 46 that is bent in an L shape on the side of the outer case 2.

The closing portion 42 has a circular shape corresponding to the opening shape of the outer case 4, and a core-shaped iron core portion 60 is formed on one surface side of the central portion by a molding process.
That is, the iron core portion 60 is formed into a rod shape similar to a conventional iron core by subjecting the closed portion 42 of the metal base substrate 40 to a drawing process at the center thereof.

An insulating film 48 is formed on the outer surface of the closing portion 42 and the terminal portion 44 of the metal base substrate 40 by printing or applying an insulating paste or the like. Further, a conductive paste is selectively printed on the surface of the insulating film 48 by using the insulating film 48 as an insulating means.
Conductive patterns 50 and 52 are formed as a plurality of terminal patterns by a conductor forming means such as plating. The conductive patterns 50 and 52 may be used for mounting a circuit or an element associated with the electroacoustic transducer for downsizing and simplification of an electronic device, and need not be a mere lead.

In the case of this embodiment, the lead portions 22, 24 of the coil 20 of the magnetic drive unit 5 housed in the outer case 2 are provided in the closed portion 42 at a position slightly separated from the central portion thereof.
Through holes 54 and 56 are formed for drawing out. The through holes 54 and 56 are formed by punching a magnetic plate as a material before the metal base substrate 40 is bonded to the outer case 2.

The lead portions 22 and 24 drawn out from the through holes 54 and 56 are electrically connected to the conductive patterns 50 and 52 with solder or a conductive adhesive. Also,
The through holes 54 and 56 are filled with an insulating agent 53 as an insulating means and a fixing means. As a result, the lead portion 2
It is possible to prevent unnecessary stress from being applied to the wires 2 and 24, protect the electroacoustic transducer from an accident such as disconnection, and contribute to improvement in reliability of the electroacoustic transducer.

The outer case 2 has a cylindrical shape formed by molding a synthetic resin, and its basic structure is the same as that of a conventional electroacoustic transducer. However, in this embodiment, a metal base substrate 40 is used as a base. Since the iron core portion 60 is formed integrally with the portion 4, the effective length of the iron core portion 60 is shortened and the height of the electroacoustic transducer is reduced in the electroacoustic transducer of this embodiment. It is clear that

The iron core portion 60 is the metal base substrate 4
Since it is formed of 0, it does not have an auxiliary function such as the conventional coupling means, simply functions as a magnetic core, and has no mechanical coupling with the base portion as in the conventional case. It forms a magnetic closed circuit that is integral with 40 and constitutes a part of the magnetic path of the magnetic drive unit 5. For this reason, the magnetic characteristics are good, and thus the acoustic characteristics are also positively affected.

A coil 20 is wound around the iron core portion 60, and an annular magnet 26 is installed around the iron core portion 60 to form the magnetic drive unit 5.
The magnet 26 is firmly fixed to the upper surface of the metal base substrate 40 with an adhesive or the like, with a slight distance from the periphery of the coil 20.

A vibrating plate 30 that forms a closed magnetic path with the magnet 26 and is driven by an oscillating magnetic field from the iron core portion 60 of the magnetic drive unit 5 is installed. The peripheral edge of the vibration plate 30 is fixed to a seating surface formed on the inner peripheral portion of the spacing ring 28 provided so as to surround the magnet 26. Inside the outer case 2, a step portion 27 is provided to form a small diameter on the front side and a large diameter on the rear side, and the large diameter portion is fitted with a spacing ring 28 for mechanical positioning and fixing. It has been done.

Further, in the central portion on the outer surface side of the diaphragm 30,
A magnetic piece 34 for fixing the mass to the diaphragm 30 and improving the magnetic efficiency is fixed. A resonance space 36 is formed by the exterior case 2 on the front side of the vibration plate 30, and a cylindrical sound emission hole 38 that opens the resonance space 36 to the outside air is provided in a form facing the magnetic piece 34. Has been.

Next, FIG. 3 shows a concrete example of the metal base substrate 40. The metal base substrate 40 is
It is a closing means for closing the outer case 2, and magnetically constitutes a part of the closed magnetic path and is made of a magnetic plate in order to have appropriate rigidity. Therefore, the conductive pattern 5 forming a terminal for pulling out the lead portions 22 and 24 to the outside
0 and 52 are formed. In this embodiment, the insulating coating 48 is formed on the surface of the metal base substrate 40 with an insulating paste or the like, and the conductive pattern 5 is formed on the surface with the conductive paste.
0 and 52 are formed. The insulating film 48 may be formed of an insulating paint, an oxide film or the like, and the conductive patterns 50 and 52 may be formed of copper foil or the like.

According to this structure, as shown in FIG. 4, the closing portion 42 and the terminal portion 44 are placed in accordance with the conductive pattern 64 of the printed circuit board 62 of the electronic device, and electrically connected with the solder 66. , Can be mechanically fixed. That is, there is no need to provide a separate member for installing the electroacoustic transducer, and the mechanical structure and electrical connection structure around the electroacoustic converter can be simplified.

In this electroacoustic transducer, the base portion 4 is simplified by using the metal base substrate 40 in which the iron core portion 60 is integrated, and the iron core portion 60 has a function other than a magnetic function with the flattening. Since it is not used as a connecting member for other members and the conventional length for crimping is unnecessary, in addition to simplifying the configuration by reducing the number of parts,
The processing or assembling process could be simplified. In addition, the use of the metal base substrate 40 has an effect of suppressing unnecessary vibration, and contributes to improvement of acoustic characteristics.

Next, FIG. 5 shows another embodiment of the electroacoustic transducer of the present invention. That is, the metal base substrate 40
The bent portion 46 provided on the terminal portion 44 may be formed toward the back side as shown in FIG. 5, and its form does not hinder the hybridization. In particular, the electroacoustic transducer using the metal base substrate 40 brings about not only flattening but also a revolution in the terminal form, and the degree of freedom from simple leads to simplification of a part of the circuit and fixing means, etc. It will increase Therefore, with such a configuration, the printed circuit board 6 to which the electroacoustic transducer is to be mounted is
A through hole 68 into which the bent portion 46 can be inserted is formed on the second side, and after the bent portion 46 is inserted and temporarily fixed, the solder 66 or the conductive material is provided between the bent portion 46 and the conductive pattern 64 on the back surface side. Adhesive can be placed and mechanically secured with electrical connections. Compared with the embodiment shown in FIG. 4, there is an advantage that the fixing strength to the printed board 62 is further increased and the reliability can be improved.

Further, in the embodiment, the case where the terminal portion 44 and the printed circuit board 62 are connected or fixed with solder or a conductive adhesive has been described. However, the electroacoustic transducer of the present invention includes a screw and a nut. Other mechanical fixing means, such as cutting and raising of the chassis may be used without impairing the degree of freedom of the fixing means.

[0030]

As described above, according to the present invention,
Since the iron core part is integrally formed on one surface side of the base member made of magnetic material and the terminal pattern is formed on the other surface side with the insulating film interposed, the iron core as a conventional independent component is omitted. As a result, the number of parts can be reduced and the configuration can be simplified, and the electroacoustic transducer can be flattened by hybridizing the base member, and the acoustic characteristics can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the electroacoustic transducer of the present invention.

FIG. 2 is a plan view showing a back surface portion of the electroacoustic transducer shown in FIG.

3 is a cross-sectional view showing a configuration of a metal base substrate in the electroacoustic transducer shown in FIG.

FIG. 4 is a vertical cross-sectional view showing a mounted state of the electroacoustic transducer shown in FIG.

FIG. 5 is a vertical cross-sectional view showing another embodiment of the electroacoustic transducer of the present invention and a mounting state thereof.

FIG. 6 is a vertical sectional view showing a conventional electroacoustic transducer.

FIG. 7 is a plan view showing a back surface portion of the electroacoustic transducer shown in FIG.

[Explanation of symbols]

 2 Outer case 5 Magnetic drive part 20 Coil 22, 24 Lead part 30 Vibration plate 40 Metal base substrate (base member) 48 Insulating film 50, 52 Conductive pattern (terminal pattern) 60 Iron core part

Claims (1)

[Claims] 1. An electroacoustic transducer in which an exterior case includes a magnetic drive unit that magnetically vibrates the diaphragm by receiving an electric signal together with the diaphragm, and the electroacoustic transducer is made of a magnetic material and is formed by molding the magnetic material. A base member integrally forming an iron core portion on one surface side to close the opening of the outer case, and an insulating film formed on the other surface side of the base member and wound around the iron core portion. An electroacoustic transducer comprising: a terminal pattern to which a lead portion of a coil is to be connected.