JPH06105394A - Electroacoustic transducer - Google Patents

Abstract

PURPOSE:To make the size of the transducer small and to make the transducer flat and to improve the acoustic characteristic by forming a base member with a metallic plate, installing upright an iron core on the base member only, simplifying the structure and simplifying the processing or the assembling process. CONSTITUTION:A closing section 42 and a terminal section 44 are mounted on the transducer in matching with a conductor pattern of a printed circuit board of an electronic device, they are connected electrically by using solder and fixed mechanically. Thus, the mechanical configuration and the electric connection configuration around the electroacoustic equipment are simplified. Then a base 4 is simplified by omitting a a conventional board without any revision to the configuration of a magnetic drive section such as an effective length of an iron core 6 and a magnet 26 or the like in the electroacoustic transducer. The iron core 6 is made flat and the processing or the assembly process is simplified without using other member than the magnetic function or the like for joining member. Thus, the transducer is made small and flat to improve the acoustic characteristic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroacoustic transducer which receives an electric signal having an appropriate level and produces 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 also functions as a support member for the magnetic drive portion. The iron core 6, the base 8, the substrate 10, and the lead 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 crimping the rear portion of the iron core 6, that is, the base portion 4 has a double structure including the substrate 10 and the base 8, and the substrate 10 is not crimped. The leads 12 and 14 are fixed by tightening pins 16 and 18.

The iron core 6 constitutes a part of a magnetic drive unit, around which a coil 20 is wound, and its coil ends 22 and 24 are individually connected to the leads 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 for converting magnetic vibrations into mechanical vibrations is installed on a seating surface formed on the inner peripheral portion of the space retaining 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 leads 12 and 14, the coil 20 is excited by the electric signal, and the excitation causes the diaphragm 30 to move. , It vibrates in the vertical direction, and the vibration depends on the amplitude and frequency of the 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, and the narrowing thereof causes deterioration of the resonance effect, which adversely affects the acoustic characteristics far more than the reduction of the magnetic driving force. Such a method is not a good idea.

[0008] Therefore, an object of the present invention is to provide an electroacoustic transducer which is miniaturized and flattened without deteriorating acoustic characteristics such as a decrease in sound pressure.

[0009]

As shown in FIG. 1, an electroacoustic transducer according to the present invention is made of a metal material and forms a part of a magnetic path to close an end surface of an outer case (2). A base member (metal base substrate 40) and a coil (2) installed inside the exterior case and erected on the base member.
0) wound around an iron core (6), a magnet (26) installed on the base member and surrounding the iron core, and an end face of the magnet to form a closed magnetic path, and between the end face of the iron core. A vibrating plate (30) provided with a gap and a lead section (50, 52) provided on the insulating film (48) formed on the base member and connected to the coil. Characterize.

[0010]

In the electroacoustic transducer of the present invention, the base member is formed of a metal plate, and as a result, the base portion is simplified. That is, the conventional electroacoustic transducer has a double structure of a base and a substrate, whereas the electroacoustic transducer of the present invention has a single structure. As a result, in addition to the reduction of the number of parts, the number of parts is reduced by the amount of the board omitted.
The outer case can be flattened, and is flattened and downsized. Moreover, the simplification of the base member contributes to the effect of suppressing unnecessary vibrations, and the acoustic characteristics are improved.

In the conventional electroacoustic transducer, the iron core is the connecting means for connecting the substrate and the base. However, in the present invention, there is no function sharing as the connecting means in the iron core, and the iron core is erected on the base member. As a result, the degree of freedom in fixing the iron core is increased, and the working or assembling process is simplified.

Further, the base member has an insulating film formed as a function of a circuit board, and a lead portion is formed thereon. As a result, unlike the conventional leads, surface connection becomes possible, which can contribute to simplification of connection form such as direct attachment to a printed circuit board.

[0013]

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 the electroacoustic transducer of this embodiment, a single metal base substrate 40 as a plate-shaped base member made of a metal material is installed on the base portion 4. The metal base substrate 40 is formed by forming a terminal portion 44, which is formed by extending a part thereof in a diametrical direction, in a circular closing portion 42 that closes the opening on the back side of the outer case 2. In the case of this embodiment, a bent portion 46 bent into an L-shape is formed on the outer case 2 side.

The outer surface of the closed portion 42 and the terminal portion 44 of the metal base substrate 40 is covered with an insulating film 4 on the surface.
8, and lead portions 50 and 52 are selectively formed on the surface by means such as printing of a conductive paste. In the case of this embodiment, through-holes 54 and 56 are formed in the closed portion 42 at a position slightly separated from the center thereof, and the through-holes 54 and 5 are formed.
The coil ends 22 and 24 pulled out from 6 are electrically connected with solder or a conductive adhesive.

The outer case 2 has a cylindrical shape formed by molding a synthetic resin, and its basic structure is similar to that of a conventional electroacoustic transducer, but its height is the metal base substrate 40.
Since the base portion 4 is configured with the above, it is flattened. The effective length of the iron core 6 in the base portion 4 is set to a length excluding the portion of the iron core 6 penetrating the substrate 6 and the crimped portion in FIG. Turns out to be clearly shorter.

A through hole 58 is formed in the central portion of the metal base substrate 40, and the small diameter portion 60 of the iron core 6 is press-fitted and fixed in the through hole 58 to stand upright. That is, the iron core 6 does not have the additional function of the conventional coupling means but simply functions as the magnetic core.
In this way, the iron core 6 and the metal base substrate 40 magnetically form a closed circuit and form a part of the magnetic path of the magnetic drive unit. Further, as a fixing means of the iron core 6, a small diameter portion 60
Also, various methods such as welding and fixing with an adhesive can be used in addition to the method of screwing the through hole 58 and screwing.

A coil 20 is wound around the iron core 6, and an annular magnet 2 is formed around the coil 20.
6 is installed to configure a magnetic drive unit. 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.

The vibrating plate 3 forming a closed magnetic path with the magnet 26 and driven by the vibrating magnetic field from the iron core 6.
0 is set. 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. Exterior case 2
A step portion 27 is provided on the inside to form a small diameter on the front side and a large diameter on the rear side, and a space retaining ring 28 is fitted in this large diameter portion to be mechanically positioned and fixed. Of.

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 metal plate so as to have appropriate rigidity. Therefore, as means for pulling out the coil ends 22 and 24 to the outside, the lead portion 50,
52 is formed. In this embodiment, an insulating film 48 is formed on the surface of the metal base substrate 40 with an insulating paste or the like, and a conductive paste is applied on the surface of the insulating coating 48.
2 is formed. The insulating film 48 may be formed of an insulating paint, an oxide film or the like, and the lead portions 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 conductor 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 iron core 6
The flat length is achieved by simplifying the base portion 4 by omitting the substrate which has been conventionally required, without changing the effective length of the magnet or the form of the magnetic drive portion such as the magnet 26. No. 6 is not used as a connecting member for members other than the magnetic function, and the conventional length for crimping is not necessary. Therefore, in addition to simplifying the configuration by reducing the number of parts, processing or It is also possible to simplify the assembly process. Moreover, the simplification of the base portion 4 and the effect of suppressing the vibration that does not require the use of the metal base substrate 40 are effective, and the acoustic characteristics can be improved.

Next, FIG. 5 shows another embodiment of the electroacoustic transducer of the present invention. In the electroacoustic transducer of this embodiment, the bent portion 46 provided on the terminal portion 44 of the metal base substrate 40 is formed so as to face the back side. In this way, a through hole 68 into which the bent portion 46 can be inserted is formed on the printed circuit board 62 side to which the electroacoustic transducer is attached, and after the bent portion 46 is inserted and temporarily fixed, the through hole 68 is formed. Solder 66 or a conductive adhesive may be placed between the back side conductor pattern 64 and the back side conductor pattern 64 to be mechanically fixed together with electrical connection. As compared with the embodiment shown in FIG. 4, the fixing strength with the printed circuit board 62 is further enhanced, and the reliability can be enhanced.

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, mechanical fixing means such as screws and nuts, and cutting of the chassis. A means such as raising may be used.

[0026]

As described above, according to the present invention,
By simplifying the base portion, the structure can be simplified and the flattening can be achieved, and an electroacoustic transducer with improved acoustic characteristics can be provided.

[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 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 6 Iron core 20 Coil 26 Magnet 30 Vibration plate 40 Metal base substrate (base member) 48 Insulation film 50, 52 Lead part

Claims (1)

[Claims] 1. A base member which is made of a metal material and forms a part of a magnetic path and closes an end face of an outer case; and a coil which is installed inside the outer case and is erected on the base member so as to wind a coil. A rotated iron core; a magnet installed on the base member to surround the iron core; a diaphragm that forms a closed magnetic circuit with an end surface of the magnet and that is installed with a gap between the end surface of the iron core; An electroacoustic transducer, comprising: a lead portion that is installed on an insulating film formed on the base member and connected to the coil.