CN107682793B

CN107682793B - Sound production device

Info

Publication number: CN107682793B
Application number: CN201711092410.3A
Authority: CN
Inventors: 霍亮; 刘岩涛
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2017-11-08
Filing date: 2017-11-08
Publication date: 2020-09-22
Anticipated expiration: 2037-11-08
Also published as: CN107682793A

Abstract

The invention discloses a sound production device, which comprises a shell, a vibrating diaphragm arranged in the shell, and two vibrating diaphragms symmetrically arranged in the vibrating diaphragmThe magnetic circuit systems on two sides comprise a magnet yoke and a magnet arranged on the magnet yoke, and the magnet is also provided with a washer; the voice coil is characterized by further comprising two voice coils which are symmetrically distributed on two sides of the vibrating diaphragm, one end of each voice coil is connected to the vibrating diaphragm, and the other end of each voice coil is matched with the corresponding magnetic circuit system. The sound generating device of the invention can make the diaphragm matched with the magnetic circuit system easier to select, and the low-frequency distortion and the resonant frequency f of the generating device can be greatly reduced by matching the diaphragm and the magnetic circuit system₀Nearby distortions.

Description

Sound production device

Technical Field

The invention relates to the field of electroacoustic conversion, in particular to a sound production device.

Background

The loudspeaker is an important acoustic device in electronic equipment and comprises a shell, a vibrating diaphragm arranged in the shell, a voice coil fixedly connected to the vibrating diaphragm and a magnetic circuit system. When the voice coil receives an audio signal, the voice coil drives the diaphragm to vibrate under the action of the magnetic circuit system, so that surrounding air is driven to sound, and further conversion from electric energy to sound energy is realized.

With this conventional speaker configuration, the voice coil is displaced significantly when it is operated at low frequencies. At this moment, the acting force of the magnetic circuit system on the voice coil is greatly weakened, and the influence of the stiffness coefficient of the diaphragm at this moment can cause larger low-frequency THD distortion.

Disclosure of Invention

One object of the present invention is to provide a new solution for a sound generating device.

According to a first aspect of the invention, a sound production device is provided, which comprises a shell, a vibrating diaphragm arranged in the shell, and a magnetic circuit self-check, wherein the magnetic circuit assembly comprises two magnetic circuit systems symmetrically arranged on two sides of the vibrating diaphragm, each magnetic circuit system comprises a magnetic yoke and a magnet arranged on the magnetic yoke, and a washer is further arranged on the magnet; the voice coil is characterized by further comprising two voice coils which are symmetrically distributed on two sides of the vibrating diaphragm, one end of each voice coil is connected to the vibrating diaphragm, and the other end of each voice coil is matched with the magnetic gap of the corresponding magnetic circuit system.

Optionally, the housing includes a first housing and a second housing symmetrically distributed on two sides of the diaphragm, and the diaphragm is clamped between the first housing and the second housing; and the two magnetic circuit systems are respectively arranged on the first shell and the second shell.

Optionally, four magnetic yokes are arranged in each magnetic circuit system, and the four independent magnetic yokes surround a rectangular structure.

Optionally, one yoke is provided in each magnetic circuit system.

Optionally, the magnetic circuit system is a single magnetic circuit structure or a double magnetic circuit structure.

Optionally, the washer and the shell are injection-molded together, and the washer is exposed from the shell; and the magnets in the magnetic circuit system are positioned and arranged on the washer.

Optionally, the diaphragm is a planar diaphragm.

Optionally, a dome is disposed on the diaphragm.

Optionally, two of the ball tops are arranged and attached to two sides of the diaphragm.

Optionally, a hollow part is arranged in the central area of the diaphragm, and one dome is arranged on the dome and is an FPCB plate covering the hollow part of the diaphragm; in two voice coils that are arranged on two sides of the vibrating diaphragm, a lead is respectively connected to the FPCB plate.

According to the sound production device, because the two magnetic circuit systems symmetrically distributed on the two sides of the vibrating diaphragm are adopted, no matter which side of the vibrating diaphragm is relatively large in displacement, the voice coil on one side can be extended into the magnetic gap of the magnetic circuit systems; that is, even if the diaphragm is displaced a relatively large amount, the voice coil can still be coupled to the region of the magnetic circuit system where the magnetic density is relatively high. The magnetic circuit component with a symmetrical structure is adopted, so that the whole magnetic circuit component can have symmetrical BL (X), a vibrating diaphragm matched with the magnetic circuit component can be selected more easily, and the low-frequency distortion and the resonant frequency f of the generating device can be greatly reduced by matching the magnetic circuit component and the vibrating diaphragm₀Nearby distortions.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a cross-sectional view of a sound generating device of the present invention.

Fig. 2 is an exploded view of a part of the structure of the sound generating device of the present invention.

Fig. 3 is a schematic diagram of a first embodiment of the magnetic circuit system of the present invention.

Fig. 4 is a schematic diagram of a second embodiment of the magnetic circuit system of the present invention.

Fig. 5 is a sectional view of another embodiment of the sound generating device of the present invention.

Fig. 6 is a schematic structural view of the washer and the housing of the present invention.

Fig. 7 is a schematic diagram of a third embodiment of the magnetic circuit system of the present invention.

Fig. 8 is an exploded view of a voice coil and a diaphragm according to the present invention.

Fig. 9 and 10 are schematic diagrams of two different implementations of matching the diaphragm and the magnetic circuit assembly.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

The invention provides a sound production device which comprises a shell, a vibrating diaphragm and magnetic circuit components, wherein the magnetic circuit components comprise two magnetic circuit systems symmetrically arranged on two sides of the vibrating diaphragm.

The diaphragm may be mounted in the housing with the magnetic circuits distributed on opposite sides of the diaphragm such that the two magnetic circuits are symmetrical with respect to the diaphragm. And voice coils are respectively arranged on two sides of the vibrating diaphragm, one end of each voice coil is connected to the vibrating diaphragm, and the other end of each voice coil is matched with the magnetic circuit system on the side. After the two voice coils are electrified with alternating current, the two voice coils are respectively matched with respective magnetic circuit systems together, so that the vibrating diaphragm is driven to produce sound together.

The sound generating device of the present invention may be a microphone, a speaker or other sound generating devices known to those skilled in the art. The sound generating device can be applied to electronic equipment, such as a mobile phone, a computer, an IPAD, a player and the like. Therefore, the invention also provides electronic equipment which comprises the sound generating device.

According to the sound production device, because the two magnetic circuit systems symmetrically distributed on the two sides of the vibrating diaphragm are adopted, no matter which side of the vibrating diaphragm is relatively large in displacement, the voice coil on one side can be extended into the magnetic gap of the magnetic circuit systems; that is, even if the diaphragm is displaced to a large extent, the voice coil can still be matched with the region with higher magnetic density in the magnetic circuit system, so that the low-frequency distortion of the generating device can be greatly reduced.

The bl (x) curve, kms (x) curve and rms (v) curve for measuring important design quantities inside the sounding device take displacement x of the diaphragm and a derivative thereof, namely speed v, as variables, so that THD needs to be approximately expressed by the displacement x.

For a magnetic circuit system, the farther from the center of the magnetic gap, the smaller the magnetic field strength B and the smaller the value of Bl as the voice coil moves in the magnetic gap. The bl (x) curve of the magnetic circuit assembly in the sound generating device is therefore non-linear.

In addition, when the voice coil moves in a balanced displacement mode, the displacement x is small, the restoring force is mainly provided by the deformation of the folded ring, and the restoring force is small; the larger the displacement x of the voice coil, the larger the deformation of the edge, the larger the material is stretched, and the larger the restoring force, so that the stiffness coefficient k is increased with the displacement x, i.e., kms (x), is a non-linear curve.

Furthermore, the mechanical damping rms (v) of the vibration system of the sound generating device changes with the vibration speed of the diaphragm, and the vibration speed v of the diaphragm is the first derivative of the displacement x. The mechanical damping rms (v) is therefore a non-linear curve.

When the sounding device is at low frequency, the amplitude x is large, the speed v is small, the damping force rms (v) v of the sounding device can be ignored, and the restoring force reaches the maximum value. At this time, the driving force bl (x) i and the restoring force kms (x) x are major influencing factors of low-frequency harmonic distortion, and the vibration system of the loudspeaker can be simplified into vibration of a mass point without considering that the diaphragm generates divided vibration or polarization, and the resultant force received by the vibration system is: f (x) bl (x) i-kms (x) x.

When at low frequency ω, displacement x is relatively large, and f (x) does not deviate from f (x) - ω as displacement x becomes larger²The linear relationship of x reduces the distortion of the sound generating device.

According to the sound production device, the magnetic circuit components are two magnetic circuit systems symmetrically arranged on two sides of the vibrating diaphragm, so that a Bl (X) curve provided by the magnetic circuit components is symmetrical relative to an original point of displacement X, and BL (X) is a flat straight line or a curve gradually bending upwards along with the increase of the displacement X by adjusting the length of the voice coil and the size of a magnetic gap matched with the voice coil.

This just makes can select for use corresponding vibrating diaphragm more easily to cooperate with magnetic circuit component together, thereby the both coactions can reduce sound generating mechanism's low frequency harmonic distortion.

Referring to fig. 9, for example, when bl (X) of the magnetic circuit assembly is a curve that gradually bends upward with the increase of the displacement X, a planar diaphragm may be used, and the kms (X) curve of the planar diaphragm itself gradually bends upward with the increase of the displacement X. IIAre matched together such that f (x) bl (x) i-kms (x) x may not deviate from f (x) ω²The linear relationship of x.

Referring to fig. 10, when bl (x) of the magnetic circuit assembly is a flat straight line, a diaphragm having a flat kms (x) may be selected, for example, by designing the diaphragm in a corrugated ring shape or a pattern shape, so that kms (x) of the diaphragm is a flat straight line. The magnetic circuit component is matched with the diaphragm, so that F (x) Bl (x) i-Kms (x) x can not deviate from F (x) omega²The linear relationship of x.

At the resonance frequency f₀Nearby, the working characteristics of the sound generating device are: the vibration speed of the diaphragm is maximum, and the restoring force at the equilibrium position (x ═ 0) is zero (i.e., kms (x) x ═ 0), and at this time, the driving force bl (x) i and the damping force rms (v) dx/dt are main influencing factors. Therefore, the magnetic circuit component with a symmetrical structure is adopted, so that BL (X) is symmetrical, when the displacement X is positioned at the balance position, the driving force reaches the maximum, and the driving force and the damping force are optimally matched, so that the resonant frequency f of the sound generating device can be obviously reduced₀Nearby THD.

Fig. 1 and 2 show a specific structure of the sound generating device of the present invention. In this embodiment, the housing 1 includes a first housing 1a and a second housing 1b symmetrically distributed on two sides of the diaphragm 4, and the first housing 1a and the second housing 1b have the same structure and are symmetrically distributed on two sides of the diaphragm 4. With reference to the orientation shown in fig. 1, the diaphragm 4 is clamped between the first housing 1a and the second housing 1b to achieve fixation of the diaphragm 4 on the housings. The first housing 1a is disposed below the diaphragm 4, and the second housing 1b is disposed above the diaphragm 4.

The two magnetic circuits are respectively marked as a first magnetic circuit 2 oppositely arranged on the first shell 1a and a second magnetic circuit 3 oppositely arranged on the second shell 1b, and the two magnetic circuits have the same structure and are symmetrically distributed on the upper side and the lower side of the diaphragm 4. Two sides of the diaphragm 4 are respectively provided with a voice coil 5, one end of the voice coil 5 is connected to the diaphragm 4, and the other end of the voice coil is matched with the magnetic gap of the corresponding magnetic circuit system. So that the two voice coils 5 can cooperate with the first magnetic circuit 2 and the second magnetic circuit 3 to drive the diaphragm 4 to vibrate and produce sound.

The magnetic circuit system of the present invention may be a single magnetic circuit structure, or may be a dual magnetic circuit or other magnetic circuit structures known to those skilled in the art. The magnet comprises a magnet yoke and a magnet arranged on the magnet yoke, wherein a washer is further arranged on the magnet. The different structures of the magnetic circuits are different, so the distribution modes of the magnets and the magnetic yokes are different, which depends on actual requirements.

Since the first magnetic circuit 2 and the second magnetic circuit 3 have the same structure, the magnetic circuit system of the present invention will be described in detail by taking the first magnetic circuit 2 as an example. In a specific embodiment of the present invention, the magnetic circuit system may be a single magnetic circuit structure, and referring to fig. 1 and 3, four magnetic yokes 20 in the first magnetic circuit 2 may be provided, and the four independent magnetic yokes 20 are mounted on the first housing 1a and together form a hollow rectangular structure.

The first magnetic circuit 2 further includes a magnet 21 correspondingly disposed on the yoke 20, and a washer 22 disposed on the magnet 21. The magnet 21 and the side wall of the yoke 20 form a magnetic gap 23 of the magnetic circuit system. When mounted, the voice coil 5 is connected at one end to the diaphragm 4 and at the other end extends into the magnetic gap 23 of the magnetic circuit.

In another embodiment of the invention, the yoke 20 in the first magnetic circuit 2 may be provided with one, see fig. 4. The yoke 20 includes a bottom portion 20a, and side wall portions 20b formed at positions around the bottom portion 20 a. The four side wall portions 20b may be formed at four edge areas of the bottom portion 20a, for example. Four magnets 21 are correspondingly arranged and distributed at the periphery of the bottom portion 20a, and each magnet 21 and the corresponding side wall portion 20b enclose a magnetic gap 23 of the magnetic circuit system.

Preferably, a hollow is formed in a central region of the yoke bottom 20a to form an annular structure; the side wall portion 20b is formed at the hollowed-out edge position.

In another embodiment of the present invention, the magnetic circuit system may be a dual magnetic circuit structure, as follows: the yoke 20 of the first magnetic circuit 2 is flat, and further includes a central magnet 26 disposed in a central region of the yoke 20, the central magnet 26 may be bonded to the central region of the yoke 20 by an adhesive, and a central washer 27 may be bonded to an end surface of the central magnet 26. The first magnetic circuit 2 further comprises a side magnet 24 arranged around a central magnet 26. Four side magnets 24 are arranged and attached to the magnetic yoke 20 at positions opposite to the four side walls of the central magnet 26; and a rim washer 25 is further provided on the end face of each rim magnet 24. The side magnets 24 and the side walls of the center magnet 26 form a magnetic gap of the first magnetic circuit 2.

The first magnetic circuit 2 is mounted on the first case 1a, and the second magnetic circuit 3 is mounted on the second case 1 b. Specifically, the first and second cases 1a and 1b have hollow inner cavities, and end faces for mounting respective magnetic circuit systems are provided on the inner walls of the two cases. The positioning and installation of the magnetic circuit system are realized through the end face.

In a preferred embodiment of the present invention, the washer in the magnetic circuit system may be injection molded with the housing, and the washer is exposed from the housing; the magnet and other structures in the magnetic circuit system can be positioned and installed on the washer.

Regardless of the four independent yoke structures shown in fig. 3 or the integrated yoke structure shown in fig. 4, the four washers 22 on the magnets may be independent from each other or integrated. In a preferred embodiment of the present invention, the washer 22 is an integral ring, and the washer 22 is bonded to the inner wall of the first casing 2 by injection molding, so that the washer 22 can be used as a positioning surface and a mounting surface for mounting the first magnetic circuit 2, so as to realize positioning and mounting of the first magnetic circuit 2.

When the magnetic circuit system adopts the above-mentioned double-magnetic circuit structure, the side washer 25 may be injection-molded together with the housing, and the side washer 25 may be integrated into a ring shape, which is not described in detail herein.

The diaphragm 4 of the present invention may adopt a conventional diaphragm structure, which may include, for example, a vibrating portion in the middle region, a connecting portion at the edge for connecting to the housing, and a corrugated portion between the connecting portion and the vibrating portion, and such a diaphragm structure is well known to those skilled in the art and will not be described in detail herein. In a preferred embodiment of the present invention, the diaphragm 4 of the present invention is a planar diaphragm. The planar diaphragm can better suppress polarization of the diaphragm.

Preferably, in order to improve the vibration performance of the diaphragm 4, a dome 6 is provided on the diaphragm 4. In order to ensure the symmetry of the sound generating device, two dome tops 6 may be provided, and are respectively attached to two opposite sides of the diaphragm 4, as shown in fig. 1.

In a preferred embodiment of the present invention, referring to fig. 8, a hollow 40 is provided in the central region of the diaphragm 4, and one of the domes 6 is provided, which is an FPCB plate covering the hollow region of the diaphragm 4. That is to say, the FPCB board itself can be used as a dome structure of the diaphragm 4, and it can be attached to the upper surface of the diaphragm 4, and also can be attached to the lower surface of the diaphragm 4, so as to cover the hollow 40 in the central area of the diaphragm 4. This FPCB board can also play the effect of switching on when playing the ball top effect to the transmission of sound generating mechanism internal circuit signal.

Wherein, the lead wires of the voice coils positioned at both sides of the diaphragm 4 are respectively connected to the FPCB board. Specifically, the two voice coils may be respectively referred to as a first voice coil 51 located below the diaphragm 4, and a second voice coil 50 located above the diaphragm 4, referring to fig. 8. After the first voice coil 51 and the second voice coil 50 are attached to both sides of the diaphragm 4, a lead 51a of the first voice coil 51 may be connected to the FPCB board by soldering, and the other lead 51b is bent in a reverse U-shape and protrudes from the case. A lead 50a of the second voice coil 50 may be connected to the FPCB board by soldering, and the other lead 50b is reversely bent in a U-shape and protrudes from the case.

The lead 51a is drawn from the first voice coil 51 at a position symmetrical to the lead 50a from the second voice coil 50 with respect to the center of the FPCB board. Referring to the view direction of fig. 8, a lead wire 51a is drawn from the lower right corner of the first voice coil 51, and a lead wire 50a is drawn from the upper left corner of the second voice coil 50. The other leads of the first voice coil 51 and the second voice coil 50 may also be symmetrical with respect to the center of the FPCB board, and will not be described in detail herein. By adopting the structural design, the two voice coil structures can be symmetrically distributed, so that the polarization of the vibrating diaphragm can be inhibited as much as possible.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A sound generating device, characterized by: the magnetic circuit component comprises two magnetic circuit systems symmetrically arranged on two sides of the vibrating diaphragm, each magnetic circuit system comprises a magnet yoke and a magnet arranged on the magnet yoke, and the magnet is also provided with a washer; the voice coil is symmetrically distributed on two sides of the vibrating diaphragm, one end of each voice coil is connected to the vibrating diaphragm, and the other end of each voice coil is matched with the magnetic gap of the corresponding magnetic circuit system;

a dome is arranged on the vibrating diaphragm;

two ball tops are arranged and attached to two sides of the vibrating diaphragm; or

The center area of the vibrating diaphragm is provided with a hollow part, and one ball top is arranged and is an FPCB plate covering the hollow part of the vibrating diaphragm; one lead wire of each of the two voice coils positioned at the two sides of the vibrating diaphragm is connected to the FPCB board;

the shell comprises a first shell and a second shell which are symmetrically distributed on two sides of the vibrating diaphragm, and the vibrating diaphragm is clamped between the first shell and the second shell; the first shell and the second shell have the same structure and are symmetrically distributed on two sides of the vibrating diaphragm.

2. The sound generating apparatus of claim 1, wherein: the two magnetic circuit systems are respectively arranged in the first shell and the second shell.

3. The sound generating apparatus of claim 1, wherein: the number of the magnetic yokes in each magnetic circuit system is four, and the four independent magnetic yokes surround a rectangular structure.

4. The sound generating apparatus of claim 1, wherein: and one magnetic yoke is arranged in each magnetic circuit system.

5. The sound generating apparatus according to claim 3 or 4, wherein: the magnetic circuit system is of a single magnetic circuit structure or a double magnetic circuit structure.

6. The sound generating apparatus of claim 1, wherein: the washer and the shell are injected and molded together, and the washer is exposed out of the shell; and the magnets in the magnetic circuit system are positioned and arranged on the washer.

7. The sound generating apparatus of claim 1, wherein: the diaphragm is a planar diaphragm.