KR20040110467A - Small speaker and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A small-sized speaker using a separate bottom plate and a fabricating method thereof are provided to arrange efficiently a magnetic circuit and improve density of magnetic flux within a gap by coupling two magnet assemblies to each other. CONSTITUTION: A first magnet assembly is formed by coupling a first top plate(22) having a center hole, a first magnet(23), and a first bottom plate(24) to a frame(21) having an internal space. A second magnet assembly(50) is formed by adhering a second top plate(58), a second magnet(59), and a second bottom plate(54). A vibration plate assembly including a diaphragm and a voice coil is adhered to the first magnet assembly. The first magnet assembly is adhered to the second magnet assembly.

Description

Small speaker and its manufacturing method {SMALL SPEAKER AND MANUFACTURING METHOD THEREOF}

The present invention relates to a small speaker, and more particularly, to assemble a magnet (permanent magnet) into the speaker, and to form and combine a magnet having a different magnetization direction into a separate sub-assembly, thereby effectively combining the magnetic circuit. The present invention relates to a small speaker using a separated bottom plate and a method for manufacturing the same.

The loudspeaker converts electrical energy into mechanical energy by a voice coil existing between the gaps, according to Fleming's left-handed law, in which a current-carrying conductor is forced when it is in a magnetic field.

That is, when a current signal containing several frequencies is applied to the voice coil, the voice coil generates mechanical energy according to the strength of the current and the magnitude of the frequency, and ultimately generates vibrations in the diaphragm attached to the voice coil. The ear produces a sound pressure of a predetermined magnitude.

The magnetic circuit of the speaker is designed so that magnetic flux can be bridged at right angles to the voice coil existing in the air gap by using a magnet and an upper plate in the yoke made of ferrous metal. The voice coil is bonded to the diaphragm to generate electromotive force up and down by an input signal, thereby vibrating the diaphragm bound to the frame to generate sound pressure. The diaphragm has various shapes of waves in order to remove the buckling phenomenon and excellent response during the up and down oscillation, and the shape of the diaphragm acts as a design variable having the greatest influence on the frequency characteristics.

In recent years, in order to meet the trend of the commercialization of high-energy magnets and the molding technology of microstructures, and the trend of miniaturization and weight reduction in the information and communication field, the speaker has been continuously miniaturized and reduced in weight and high performance. In addition, as the size of the LCD window increases in the mobile communication terminal, the miniaturization of the speaker, which is a sound reproduction component, is accelerating.

However, when miniaturization of the speaker is realized according to such a requirement, the magnetic flux density in the air gap is lowered due to the reduced volume of the magnet, and as a result, the sound pressure is reduced.

Therefore, the development of a speaker with a stronger magnetic circuit that can overcome this has been required.

In order to solve this problem, Korean Patent Application Publication No. 2002-0073876 discloses a dual magnet structure in which a ring-shaped auxiliary magnet is added to a conventional magnet structure.

Referring to FIG. 1, a small speaker having the dual magnet structure is illustrated, and a frame 11 having a space on an inner surface thereof, a sound generating diaphragm 15 having an outer end portion fixed to an upper end of the frame, and the diaphragm. The voice coil 16 is fixed to the lower end of the cylindrical coil 16, the main magnet 19 magnetized in the vertical direction embedded in the frame, the upper plate (18) attached to the main magnet to form a magnetic circuit, the magnet And a yoke 14 for forming a magnetic circuit and an auxiliary magnet 13 embedded in the frame in the form of a ring.

However, such a conventional method of manufacturing a small speaker is magnetized by first seating the ring-shaped auxiliary magnets 12 and 13 on the frame 11 and then in the opposite direction to the auxiliary magnets 12 and 13. The magnetized main magnet parts 18 and 19 are bonded to the frame using a jig (not shown), and then the diaphragm parts 15 and 16 and a protective plate (not shown) are used.

However, in the conventional manufacturing method as described above, the output sound pressure can be increased by an average of 2 to 3 dB by using the auxiliary magnet. However, since the magnetization direction of the main magnet and the auxiliary magnet is different, the iron that is magnetized during the process is different. When the speaker is vibrated, it may cause noise and defects. In addition, when assembling the magnetized magnets, an attraction force may occur between the main magnet and the auxiliary magnet, causing a void defect.

In addition, when combining the auxiliary magnet and the magnet magnetized in the opposite direction, there is a problem that an unnecessary space is generated due to an error in the magnet position generated by using the jig and formation of a space for inserting the jig.

The present invention is to overcome the above-mentioned conventional problems, an object of the present invention is to assemble a magnet to a speaker, and then to a magnet having a different magnetization direction as a separate sub-assembly and bonded to the speaker, production efficiency The present invention provides a method of manufacturing a compact speaker that reduces defects and improves the demagnetization process.

It is also an object of the present invention to provide a compact speaker capable of outputting high-quality sound as well as miniaturization and thinning by improving the magnetic force in the gap of the magnetic circuit formed between two magnets.

1 is a cross-sectional view showing a small speaker according to the prior art.

2A to 2D are assembly views showing a method of manufacturing a small speaker as the first embodiment of the present invention.

3 is a magnetic force diagram according to the first embodiment of the present invention.

4 is a sectional view of a speaker functioning as an actuator which is a second embodiment of the present invention;

Fig. 5 is a sectional view of a speaker serving as another actuator functioning as a third embodiment of the present invention.

6 is a graph showing the effect of increasing the sound pressure of the compact speaker according to the present invention.

◎ Explanation of symbols for main part of drawing

11, 21, 101, 201: frames

12, 22, 102, 202: first top plate

13, 23, 103, 203: first magnet (secondary magnet)

15, 35, 105, 205: diaphragm

16, 36, 106, 206: Voice Coil

18, 58, 108, 208: second top plate

19, 59, 109, 209: Second magnet (main magnet)

24, 104, 204: first lower plate

54, 114, 214: second lower plate 107, 207: weight

110, 210: Upper suspension spring

111, 211: lower suspension spring 120: vibration generating coil

As a means for achieving the above object, a method of manufacturing a small speaker according to the present invention, the frame having a space on the inner surface, having a hole in the center portion, the first upper plate, the first magnet and the first lower plate to the frame Combining therein to form a first magnet assembly; Bonding a second upper plate, a second magnet and a second lower plate, which can be inserted into the central hole, to form a second magnet assembly; Bonding a diaphragm assembly consisting of a diaphragm and a voice coil to the first magnet assembly; And attaching the second magnet assembly to the first magnet assembly to which the diaphragm assembly is bonded.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2A to 2D are assembly views showing the manufacturing method of the small speaker of the first embodiment according to the present invention. As shown, the protection plate 40, the diaphragm assembly 30, the first magnet assembly 20, and the second The magnet assembly 50 is comprised.

First, referring to FIG. 2A, in order to configure the first magnet assembly 20, a frame 21 having a space on an inner surface thereof, a ring-shaped first magnet 23, and a first upper plate ( The first magnet assembly 20 is formed by joining 22) and the first bottom plate 24 through insert injection. Here, the frame 21 serves to determine the size and shape of the speaker by fixing the diaphragm assembly 30 and the magnetic circuit (22, 23, 24). The first magnet 23, the first upper plate 22, and the first lower plate 24 may have a track shape, an elliptical shape, or a square shape. The use of the track and the square magnetic circuit as described above can evenly distribute the magnetic flux on the edge portion of the diaphragm, thereby reducing the distortion rate by vibrating the diaphragm as a whole uniformly and smoothly during sound reproduction.

At this time, the first upper plate 22 and the first lower plate 24 respectively have a step in the outer diameter portion “A”, thereby inserting the frame in a mold (not shown) composed of upper and lower molds. When inserting, make sure that it does not break out and that it can be tightly coupled.

The first magnet 23 is a neodymium (Nd) magnet, which is one of rare earth magnets, and has a strong magnetic energy, and is widely used for light, thin and high-tech products. Such Nd magnet type speakers are mainly incorporated in notebook computers, small personal computers, slim computers or LCD monitors.

Referring to FIG. 2B, the diaphragm assembly 30 including the diaphragm 35 and the voice coil 36 is attached to the first magnet assembly 20.

The diaphragm 35 has a concave shape in the inner direction and is assembled to the upper surface of the frame 21 so as to be naturally shaken up and down.

The voice coil 36 attached to the diaphragm 35 is positioned between the inner diameter of the first upper plate 22 and the outer diameter of the second upper plate 58 so that when a current is selectively applied from the outside, the flow of the magnetic field By doing the linear reciprocating motion up and down with the diaphragm 35.

Referring to FIG. 2C, a protector 47 for protecting the diaphragm assembly 30 which performs a fine shaking motion is coupled to the diaphragm assembly.

Referring to FIG. 2D, a second upper plate 58, a second magnet 59, and a second lower plate 54 may be bonded to each other to be coupled to a central portion of the first magnet assembly 20. After forming the two magnet assembly 50, it is finally bonded to the assembled first magnet assembly 20, the diaphragm assembly 30 and the protective plate 40. Such bonding means include bonding and spot or welding. Here, as in the first magnet assembly 20, the second magnet 59, the second upper plate 58 and the second lower plate 54 may be a track, oval or square shape, and the second Magnets also use Nd magnets.

In this case, the first magnet 23 and the second magnet 59 should be magnetized in opposite directions so that the directions of the magnetic poles are different from each other. By making the direction of the magnetic field formed by these two magnets, i.e., the direction of the lines of magnetic force, the magnetic flux is increased to obtain a high output even under the same input.

In addition, in order to couple the second magnet assembly 50 to the first magnet assembly 20, the inner diameter of the first lower plate 24 and the outer diameter of the second lower plate 54 are stepped (“B”). ) To engage with each other. In addition, the inner diameter of the first lower plate 24 and the outer diameter of the second lower plate 54 may be diagonally connected to be engaged with each other.

In such a small speaker, an alternating current is applied through a lead wire (not shown) from the outside to form a magnetic field in a voice coil in a magnetic circuit composed of an upper plate, a magnet, and a lower plate. have. As shown in FIG. 3, the lines of magnetic force from the north pole of the second magnet 59 may include the second upper plate 58, the voice coil 36, the first upper plate 22, the first magnet 23, and the first magnet 23. After passing through the lower plate 24 in order to form a magnetic field directed to the S pole of the second magnet 59, the voice coil functions as a speaker using the magnetic flux generated by the magnetic circuit.

In addition, in addition to the function of a small speaker capable of obtaining a sound pressure much higher than the existing output sound pressure, a second embodiment according to the present invention that can implement the actuator is shown in FIG.

In the second embodiment, a frame 101 having a space on an inner surface, a ring shape having a hole in a central portion thereof, and a lower surface of the first upper plate 102, a first magnet 103, and the first magnet 103 are provided. The first lower plate 104 is bonded, the second upper plate 108, which can be inserted into the hole in the center portion, the second magnet 109 magnetized in the opposite direction to the first magnet, and the second An inner diameter of the second lower plate 114 adhered to the lower surface of the magnet 109, the diaphragm 105 assembled to the upper surface of the frame 101, and supported to shake up and down, and the first upper plate 102. And a voice coil 106 provided between the outer diameter of the second upper plate 108 to vibrate the diaphragm 105 while linearly reciprocating up and down according to the flow of the magnetic field, and a vibrating body together with the upper plate and the lower plate. Weight 107 to form, support the weight up and down It is characterized in that it is installed on the lower end of the suspension spring (110, 111) and the frame consisting for the vibration generating coil 120 for generating a vibration using a part of the magnetic flux formed as above.

The speaker functioning as an actuator has a voice coil in the magnetic circuit part on the side of the diaphragm, and when the user wants to output audio output, an AC current is applied to the voice coil to output sound, and the lower magnetic circuit has a vibration coil to output vibration. When the current is applied to the lower coil to trigger the vertical movement of the vibrating body including the weight and the components constituting the magnetic field to generate a vibration.

The third embodiment of the present invention can be represented as shown in FIG.

The first lower plate adhered to the lower surface of the first upper plate 202, the first magnet 203 and the first magnet 203 of the frame 201 having a space on the inner surface, a ring shape having a hole in the center portion Plate 204, a second top plate 208, which can be inserted into a hole in the center portion, a second magnet 209 magnetized in a direction opposite to the first magnet, of the second magnet 209 An inner diameter of the second lower plate 214 adhered to the lower surface, a diaphragm 205 assembled to the upper surface of the frame 201, and supported to oscillate up and down, and the inner diameter of the first upper plate 202 and the second upper portion. Located between the outer diameter of the plate 208, the voice coil 206 for vibrating the diaphragm 205 while linearly reciprocating up and down in accordance with the flow of the magnetic field, the weight 207 forming a vibrating body with the upper plate and the lower plate And a suspension for supporting the weight up and down. It is characterized by consisting of the spring (210, 211).

The third embodiment of the present invention has a structure in which the vibration generating coil 120 installed at the lower end of the frame 201 is omitted in the second embodiment of the present invention, and its operation principle is similar to that of the second embodiment.

6 is a graph illustrating a sound pressure increase effect of the small speaker according to the present invention. As shown, the compact speaker according to the present invention has a sound pressure increase effect of about 2dB compared to the conventional product.

What has been described above is only an embodiment for implementing a small speaker and a method of manufacturing the same according to the present invention, the scope of the present invention is not limited to the above-described embodiment, but is limited by the interpretation of the claims Crazy

As described above, the compact speaker according to the present invention has an effect of increasing the output sound pressure by an average of 2dB by combining the two magnet assemblies to efficiently arrange the magnetic circuit to improve the magnetic flux density in the air gap.

In addition, in the small speaker according to the present invention, since the jig used in the conventional magnet coupling is not used, unnecessary space can be reduced, thereby realizing light weight and small size.

In addition, according to the present invention to solve the magnet magnetization problem by using a separate second magnet assembly to provide a simplified effect of the manufacturing process.

Claims (11)

Coupling a first upper plate, a first magnet, and a first lower plate having a space having an inner space and a hole at a central portion thereof to form a first magnet assembly; Bonding a second upper plate, a second magnet and a second lower plate, which can be inserted into the central hole, to form a second magnet assembly; Bonding a diaphragm assembly consisting of a diaphragm and a voice coil to the first magnet assembly; And Adhering the second magnet assembly to the first magnet assembly to which the diaphragm assembly is bonded Method for producing a compact speaker comprising a. According to claim 1, In the forming of the first magnet assembly, a frame is formed through insert injection in a mold in which the first magnet and the first upper plate and the first lower plate each having a step portion on the outer diameter portion are formed of upper and lower molds. Manufacturing method of a compact speaker characterized in that it is molded together. According to claim 1, The first magnet and the second magnet is a method of manufacturing a compact speaker, characterized in that the magnetic poles are arranged in different directions and magnetized in opposite directions. According to claim 1, The first magnet and the second magnet is a manufacturing method of the compact speaker, characterized in that any one of a circle, track, ellipse and square shape. According to claim 1, The inner diameter of the first lower plate and the outer diameter of the second lower plate is a step of manufacturing a compact speaker, characterized in that coupled to each other by having a stepped shape. According to claim 1, The inner diameter of the first lower plate and the outer diameter of the second lower plate has a diagonal shape, the method of manufacturing a compact speaker, characterized in that coupled to each other. A frame with space inside; A first upper plate having a hole in a central portion thereof; A first magnet having a hole in the center portion; A first lower plate adhered to a lower surface of the first magnet; A second top plate, which may be inserted into a hole in the center portion of the first top plate; A second magnet inserted into a hole of a central portion of the first magnet and magnetized in a direction opposite to the first magnet; A second lower plate adhered to a bottom surface of the second magnet; A diaphragm which is assembled to an upper surface of the frame and is supported to enable shaking up and down; And A voice coil attached to the diaphragm to vibrate the diaphragm while linearly reciprocating up and down according to a magnetic field between the inner diameter of the first upper plate and the outer diameter of the second upper plate. Small speaker made including. The method of claim 7, wherein The first magnet and the second magnet is a compact speaker, characterized in that any one of a circle, track, ellipse and square shape. The method of claim 7, wherein And a protector attached to the frame to protect the diaphragm. The method of claim 7, wherein A weight forming a vibrating body together with the upper plate and the lower plate; and Suspension spring for supporting the weight up and down Small speaker made further including. The method of claim 10, The compact speaker, characterized in that further comprises a vibration generating coil installed in the lower end of the frame to generate a vibration using a portion of the magnetic flux formed as described above.