WO2020015472A1

WO2020015472A1 - Electromagnetic exciter and screen sound production apparatus

Info

Publication number: WO2020015472A1
Application number: PCT/CN2019/090122
Authority: WO
Inventors: 祖峰磊; 杨鑫峰
Original assignee: 歌尔股份有限公司
Priority date: 2018-07-17
Filing date: 2019-06-05
Publication date: 2020-01-23
Also published as: CN109068244B; CN109068244A

Abstract

Disclosed are an electromagnetic exciter and a screen sound production apparatus. The exciter comprises a housing, a vibrator assembly and a stator assembly. The stator assembly and the vibrator assembly are accommodated in the housing. The vibrator assembly is suspended in the housing by means of an elastic element, comprises a coil and a core post disposed in the coil, and is located in the magnetic field of the stator assembly. The stator assembly comprises a Halbach permanent magnet array.

Description

Electromagnetic exciter and screen sounding device

Technical field

The invention relates to the technical field of electroacoustic conversion, and more particularly, to an electromagnetic exciter and a screen sounding device.

Background technique

In order to increase the screen ratio (ie, the ratio of the screen area to the front area) of electronic products such as mobile phones, cancelling the handset has become a development trend. In some solutions, a screen sound device is used instead of the handset. The screen sounding device usually includes a screen body and an electromagnetic actuator provided on the screen body. The electromagnetic exciter vibrates, thereby driving the screen body to vibrate to produce a sound.

Existing electromagnetic exciters usually include a stator, a vibrator, and a housing. The stator includes a coil. The vibrator includes a permanent magnet and a mass connected together. The vibrator is suspended in the cavity of the casing through the elastic sheet. The coil is fixed on the inner wall of the casing.

However, such an electromagnetic actuator has a low magnetic field utilization rate and a small driving force.

In addition, the driving force varies non-linearly with the displacement of the vibrator, resulting in unstable vibration and large distortion of the radiated sound.

In addition, the stator is fixed, and the heat dissipation of the coil is poor, which makes the electromagnetic exciter generate heat seriously.

Therefore, it is necessary to provide a new technical solution to solve the above technical problems.

Summary of the invention

An object of the present invention is to provide a new technical solution for an electromagnetic actuator.

According to a first aspect of the invention, an electromagnetic exciter is provided. The exciter includes a casing, a vibrator assembly, and a stator assembly. The stator assembly and the vibrator assembly are housed in the casing, the vibrator assembly is suspended in the casing by an elastic element, and the vibrator assembly includes a coil and A core post disposed in the coil, the vibrator assembly is located in a magnetic field of a stator assembly, and the stator assembly includes a Haierback permanent magnet array.

Optionally, the Haierbeck permanent magnet array includes a first permanent magnet, a second permanent magnet, and a third permanent magnet arranged side by side along a vibration direction; the first permanent magnet and the third permanent magnet are oppositely magnetized, and The magnetization direction is parallel to the vibration direction, and the magnetization direction of the second permanent magnet is directed to the coil.

Optionally, the coil has a rectangular ring shape or a track-like ring shape, and the first permanent magnet, the second permanent magnet, and the third permanent magnet are opposed to a long side of the coil.

Optionally, it further includes a fourth permanent magnet and a fifth permanent magnet provided at both ends of the second permanent magnet in the long axis direction, and the fourth permanent magnet and the fifth permanent magnet are oppositely magnetized.

Optionally, the core post includes a sixth permanent magnet and a seventh permanent magnet arranged side by side along the vibration direction, and the sixth permanent magnet and the seventh permanent magnet are opposite to each other in a magnetization direction.

Optionally, the core post includes an eighth permanent magnet and a ninth permanent magnet arranged side by side perpendicular to the vibration direction, and the eighth permanent magnet and the ninth permanent magnet are relatively magnetized.

Optionally, the elastic element includes an elastic piece, the elastic piece includes a first connection portion, a second connection portion, and a spring arm portion located between the first connection portion and the second connection portion, and the first A connection portion is connected to the housing, and the second connection portion is connected to the vibrator assembly.

Optionally, the shell and the elastic sheet form an integrated structure.

Optionally, the elastic pieces are multiple and are respectively located on the upper side and the lower side of the vibrator component in the vibration direction; or, the multiple elastic pieces are located on the same side of the vibrator component in the vibration direction.

Optionally, the elastic arm portion is linear or V-shaped.

Optionally, a boss protruding into the cavity is formed on the shell wall of the outer shell, and the first connection portion is fixed on the boss so that the elastic arm portion is in contact with the shell wall. A gap is formed between them.

Optionally, the casing is made of a magnetically permeable material.

According to another aspect of the present invention, a screen sound device is provided. The device includes a screen body, a middle frame, and the electromagnetic actuator provided by the present invention, and the electromagnetic actuator is disposed on the screen body or the middle frame.

Optionally, it further includes foam glue, and the electromagnetic actuator is fixedly connected to the screen body or the middle frame through the foam glue; or the electromagnetic actuator is connected to the screen body or the middle frame. Frame bolted.

According to one embodiment of the present disclosure, a vibrator assembly includes a coil and a stem. The electric signal of the corresponding external circuit of the coil is vibrated by the ampere force in the magnetic field of the stator assembly. The stem can increase the inertia of the vibrator and increase its amplitude.

In addition, the Halebeck permanent magnet array makes the magnetic field more concentrated. According to Ampere's law, under the set input current, the coil receives more force, thereby improving the energy conversion efficiency of the electromagnetic exciter.

In addition, the ampere force received by the vibrator assembly during the vibration process is more uniform, which avoids the non-linear phenomenon of the driving force of the existing structure as the displacement changes, and makes the vibration more stable, thereby further reducing the radiation sound distortion.

In addition, the coil vibrates, which can effectively dissipate heat, and due to the barrier effect of air, it is difficult for the heat of the coil to be transferred to the housing, which makes the indication temperature of the electromagnetic actuator lower, which is conducive to the sound of the louder screen.

Other features and advantages of the present invention will become clear from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is a schematic structural diagram of a stator assembly and a vibrator assembly according to an embodiment of the present invention.

FIG. 2 is a side view of a stator assembly according to an embodiment of the present invention.

FIG. 3 is a side view of another stator assembly according to an embodiment of the present invention.

4 is a cross-sectional view of an electromagnetic exciter along a short axis according to an embodiment of the present invention.

5 is a cross-sectional view of another electromagnetic exciter along a short axis according to an embodiment of the present invention.

6 is a cross-sectional view of an electromagnetic exciter along a long axis according to an embodiment of the present invention.

7 is a cross-sectional view of another electromagnetic exciter along a long axis according to an embodiment of the present invention.

FIG. 8 is a top view of an electromagnetic exciter according to an embodiment of the present invention.

Reference sign description:

11: first permanent magnet; 12: second permanent magnet; 13: third permanent magnet; 14: fourth permanent magnet; 15: fifth permanent magnet; 16: sixth permanent magnet; 17: seventh permanent magnet; 18 : Eighth permanent magnet; 19: Ninth permanent magnet; 20: Coil; 21: Magnet; 22: Housing; 23: Shrapnel; 24: Spring arm; 25: First connection; 26: Second connection 27: stator assembly; 28: vibrator assembly.

detailed description

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

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

Techniques, methods, and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but where appropriate, the techniques, methods, and equipment should be considered as part of the description.

In all examples shown and discussed herein, any specific value should be construed as exemplary only and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

It should be noted that similar reference numerals and letters indicate similar items in the following drawings, so once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

According to an embodiment of the present invention, an electromagnetic exciter is provided. The electromagnetic exciter is used for a screen sounding device and includes a housing 22, a vibrator assembly 28, and a stator assembly 27.

As shown in FIGS. 4-8, the stator assembly 27 and the vibrator assembly 28 are housed in the housing 22. The inside of the casing 22 forms a cavity. The stator assembly 27 and the vibrator assembly 28 are located in the cavity. For example, the casing 22 has a rectangular parallelepiped structure.

Preferably, the housing 22 is made of a magnetically permeable material, such as iron, cobalt, nickel, low carbon steel, and the like. In this way, on the one hand, the concentration effect of the magnetic field can be enhanced and the magnetic induction intensity can be enhanced, and on the other hand, it has a good magnetic shielding effect, and the magnetic field of the stator assembly 27 will not affect the external magnetic sensitive devices.

The vibrator assembly 28 is suspended in the housing 22 by an elastic element. The elastic element may be, but is not limited to, an elastic piece 23, a spring, or an elastic rubber piece. The vibrator assembly 28 includes a coil 20 and a stem provided inside the coil 20. The vibrator assembly 28 is located in a magnetic field of the stator assembly 27. Preferably, the stem is a magnetically permeable magnet 21. For example, the magnetizer 21 is made of materials such as iron, cobalt, nickel, low carbon steel, SPCC, and the like. The magnet guide 21 can guide more magnetic lines of force through the coil 20, which improves the magnetic induction strength at the coil 20 and increases the driving force of the vibrator assembly 28.

The stator assembly 27 includes a Halebeck permanent magnet array. Haierbeck permanent magnet array refers to an array structure assembled by a plurality of permanent magnets with different magnetization directions in a set combination manner. This structure enables the magnetic induction lines to be more concentrated at a set location, and increases the magnetic induction strength of the location, while the magnetic induction strength at other locations can be effectively reduced. In this way, the magnetic field utilization rate is effectively improved.

In the embodiment of the present invention, the vibrator assembly 28 includes a coil 20 and a stem. The electric signal corresponding to the external circuit of the coil 20 is vibrated by the ampere force in the magnetic field of the stator assembly 27. The stem can increase the inertia of the vibrator and increase its amplitude.

In addition, the Halebeck permanent magnet array makes the magnetic field more concentrated. According to Ampere's law, under the set input current, the force applied to the coil 20 is greater, thereby improving the energy conversion efficiency of the electromagnetic exciter.

In addition, the ampere force received by the vibrator assembly 28 during the vibration process is more uniform, which avoids the non-linear phenomenon of the driving force of the existing structure as the displacement changes, and makes the vibration of the vibrator assembly more stable, thereby further reducing the radiation sound distortion.

In addition, the coil 20 vibrates and can effectively dissipate heat, and due to the air blocking effect, the heat of the coil 20 is difficult to transfer to the casing 22, which makes the surface temperature of the electromagnetic exciter lower, which is beneficial to the sound of the louder screen.

In one example, a magnetic conductive plate is disposed on one end surface of the coil 20 along the vibration direction, and the magnetic conductive plate can gather magnetic induction lines, thereby further improving the magnetic induction intensity at the coil 20. The vibration direction is shown as A in FIG. 5.

In addition, the magnetically conductive plate can also serve as a connection for connection with the elastic element.

In one example, as shown in FIG. 2, the Haierbeck permanent magnet array includes a first permanent magnet 11, a second permanent magnet 12, and a third permanent magnet 13 which are arranged side by side along a vibration direction. The first permanent magnet 11, the second permanent magnet 12 and the third permanent magnet 13 are arranged in pairs on both sides of the coil 20. The first permanent magnet 11 and the third permanent magnet 13 are oppositely magnetized, and the magnetization direction is parallel to the vibration direction. The magnetizing directions of the first permanent magnet 11 and the third permanent magnet 13 point toward the second permanent magnet 12. The second permanent magnet 12 is pointed toward the second permanent magnet 12. The magnetizing direction of the second permanent magnet 12 is directed toward the coil 20, that is, N is close to the coil 20. In this structure, the first permanent magnet 11, the second permanent magnet 12, and the third permanent magnet 13 collectively form a set magnetic circuit according to the respective magnetization directions, and the magnetic fields of the three permanent magnets are more effectively concentrated, which makes The magnetic induction strength at the coil 20 can be significantly increased.

In one example, as shown in FIG. 1, the coil 20 has a rectangular ring shape or a race track type ring shape. The first permanent magnet 11, the second permanent magnet 12, and the third permanent magnet 13 are opposed to the long sides of the coil 20. The long side refers to the side having the longer length in the orthographic projection of the surface of the coil 20 perpendicular to the vibration direction. For example, the two long sides of a rectangular ring and the two straight sides of a runway ring. The long side has a longer length. Compared with the first permanent magnet 11, the second permanent magnet 12, and the third permanent magnet 13 being disposed on other sides, this arrangement makes the driving force of the vibrator assembly 28 greater.

In one example, as shown in FIG. 3, the stator bracket further includes a fourth permanent magnet 14 and a fifth permanent magnet 15 provided at both ends of the second permanent magnet 12 in the long axis direction. The long axis direction is parallel to the long side of the coil 20, the short axis is perpendicular to the long side of the coil 20, and both the long axis and the short axis are perpendicular to the vibration direction. The fourth permanent magnet 14 and the fifth permanent magnet 15 are oppositely magnetized, that is, the N poles of the two permanent magnets are close to each other. In this way, the magnetic field directions of the permanent magnets from the up, down, left, and right directions of the second permanent magnet 12 are directed toward the second permanent magnet 12. This makes the magnetic induction lines of the plurality of permanent magnets more highly concentrated, effectively improves the magnetic field at the coil 20, improves the magnetic field utilization rate, and increases the driving force of the vibrator.

In addition, the space occupied by the stator assembly 27 is small, which facilitates the miniaturization design of the electromagnetic exciter.

In one example, as shown in FIG. 4, the stem includes a sixth permanent magnet 16 and a seventh permanent magnet 17 which are arranged side by side along the vibration direction. The magnetization directions of the sixth permanent magnet 16 and the seventh permanent magnet 17 are opposite to each other, that is, the S poles of the two permanent magnets are close to each other, and the N poles are away from each other. For example, the sixth permanent magnet 16 and the seventh permanent magnet 17 are both bar magnets, and the thickness direction is parallel to the vibration direction.

When the height of the vibrator assembly 28 is high, the magnetization direction of the sixth permanent magnet 16 and the seventh permanent magnet 17 corresponds to the magnetic circuit of the Haierbeck permanent magnet array. The sixth permanent magnet 16 and the seventh permanent magnet 17 can gather the magnetic induction lines after passing through the coil 20.

In addition, since the magnetization directions of the sixth permanent magnet 16 and the seventh permanent magnet 17 follow the direction of the magnetic field formed by the stator assembly 27, the magnetic induction intensity at the coil 20 is further improved, and the driving force of the vibrator assembly 28 is improved.

In one example, as shown in FIG. 5, the stem includes an eighth permanent magnet 18 and a ninth permanent magnet 19 which are arranged side by side perpendicular to the vibration direction. The eighth permanent magnet 18 and the ninth permanent magnet 19 are relatively magnetized, that is, the N poles of the two permanent magnets are close to each other. For example, the eighth permanent magnet 18 and the ninth permanent magnet 19 are both bar magnets, and the thickness direction is perpendicular to the vibration direction.

The magnetization directions of the eighth permanent magnets 18 and the ninth permanent magnets 19 are the same as the magnetization directions of the second permanent magnets 12 that are close to each other. In this way, due to the orientation of the magnetic fields of the eighth permanent magnet 18 and the ninth permanent magnet 19, the magnetic induction lines of the second permanent magnet 12 can pass through the coil 20 to remain perpendicular to the coil 20 instead of tilting. As a rule, the direction of the ampere force received by the coil 20 is more consistent, thereby improving the reliability of the vibration.

In addition, the eighth permanent magnet 18 and the ninth permanent magnet 19 can further gather the magnetic induction lines and increase the magnetic induction intensity at the coil 20.

In addition, since the magnetization directions of the eighth permanent magnet 18 and the ninth permanent magnet 19 follow the direction of the magnetic field formed by the stator assembly 27, the magnetic induction intensity at the coil 20 is further improved, and the driving force of the vibrator assembly 28 is improved.

In one example, as shown in FIGS. 6-7, the elastic element includes an elastic piece 23. The elastic piece 23 includes a first connection portion 25, a second connection portion 26, and a spring arm portion 24 located between the first connection portion 25 and the second connection portion 26. The first connection portion 25 is connected to the housing 22, and the second connection portion 26 is connected to the vibrator assembly 28. For example, the connection is made by welding, bonding, riveting, or the like.

For example, as shown in FIG. 6, the first connection portion 25 is parallel to the second connection portion 26. The elastic arm portion 24 is linear and has a sheet-like structure, and has an obtuse angle with the first connection portion 25 and the second connection portion 26. The elastic piece 23 has a simple structure and is easy to manufacture.

Preferably, as shown in FIG. 8, the casing 22 and the elastic piece 23 form an integrated structure. For example, the casing 22 is stamped from metal, and the elastic piece 23 is integrally punched out by press molding at a position of the casing wall of the casing 22 opposite to the vibrator assembly 28 in the vibration direction. The first connection portion 25 is integrally connected with the housing 22. The second connection portion 26 is welded to the vibrator assembly 28. In this way, the processing of the elastic piece 23 and the connection between the elastic piece 23 and the casing 22 are easier.

In addition, the space of the thickness of the elastic piece 23 is saved, and the electromagnetic exciter can be made thinner.

Alternatively, as shown in FIG. 7, the elastic arm portion 24 has a V-shaped structure. A first connection portion 25 and a second connection portion 26 are formed by two free ends of the V-shaped structure extending outward. The V-shaped structure has a larger telescopic range, thereby increasing the amplitude of the vibrator assembly 28.

Optionally, as shown in FIG. 7, there are multiple elastic pieces 23 and are respectively located on the upper side and the lower side of the vibrator assembly 28 in the vibration direction. For example, there are two elastic pieces 23, which are respectively located on the upper side and the lower side of the vibrator assembly 28. In this way, the spring force received by the vibrator assembly 28 is more balanced.

Alternatively, as shown in FIG. 6, the plurality of elastic pieces 23 are located on the same side of the vibrator assembly 28 in the vibration direction. For example, there are two elastic pieces 23. The vibrator assembly 28 has a rectangular parallelepiped structure. The two elastic pieces 23 are arranged side by side on the same side of the vibrator assembly 28 in the same arrangement direction along the long axis of the vibrator assembly 28. In this way, the space of the cavity in the vibration direction can be saved, so that the electromagnetic exciter can be made thinner.

Those skilled in the art can set the number and position of the shrapnels according to actual needs.

In one example, a boss protruding into the cavity is formed on the shell wall of the shell 22. The first connection portion 25 is fixed on the boss to form a gap between the elastic arm portion 24 and the shell wall. For example, the housing 22 is formed into a boss by stamping. The first connection portion 25 is welded to the boss. In this way, the space where the elastic piece 23 vibrates is increased. When the elastic piece 23 is compressed, a gap is formed between the elastic arm portion 24 and a portion other than the boss of the casing 22, so that the elastic piece 23 can be effectively prevented from hitting the casing 22.

Those skilled in the art can set the height of the boss according to actual needs.

According to another embodiment of the present invention, a screen sound device is provided. The device comprises a screen body, a middle frame and an electromagnetic exciter provided by the present invention. The middle frame may be a middle frame of a mobile phone, a smart watch, a tablet computer, a notebook computer, a game console, or the like. The screen body is mounted on the middle frame. The electromagnetic actuator is arranged on the screen body or the middle frame. The sound generating device has the characteristics of good sound generating effect and good heat dissipation effect.

In one example, the screen sounding device further includes foam. The electromagnetic exciter is fixedly connected to the screen body or the middle frame through foam rubber.

Alternatively, the electromagnetic actuator is bolted to the screen body or the middle frame. The above connection methods can achieve a firm connection between the electromagnetic actuator and the screen body or the middle frame.

Of course, those skilled in the art may use other connection methods for connection.

Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the invention is defined by the appended claims.

Claims

An electromagnetic exciter, comprising a housing, a vibrator assembly, and a stator assembly, the stator assembly and the vibrator assembly are housed in the housing, and the vibrator assembly is suspended in the housing by an elastic element, The vibrator assembly includes a coil and a core post disposed in the coil, the vibrator assembly is located in a magnetic field of a stator assembly, and the stator assembly includes a Haierback permanent magnet array.
The electromagnetic exciter according to claim 1, wherein the Haierbeck permanent magnet array comprises a first permanent magnet, a second permanent magnet, and a third permanent magnet arranged side by side along a vibration direction; the first permanent magnet The magnetization is opposite to the third permanent magnet, and the magnetization direction is parallel to the vibration direction. The magnetization direction of the second permanent magnet is directed to the coil.
The electromagnetic exciter according to claim 2, wherein the coil has a rectangular ring shape or a track-like ring shape, and the first permanent magnet, the second permanent magnet, and the third permanent magnet are connected to all The longer sides of the coils are opposite.
The electromagnetic exciter according to claim 2, further comprising a fourth permanent magnet and a fifth permanent magnet provided at both ends of the second permanent magnet in a long axis direction, the fourth permanent magnet and The fifth permanent magnet is oppositely magnetized.
The electromagnetic exciter according to claim 2, wherein the core post includes a sixth permanent magnet and a seventh permanent magnet arranged side by side along a vibration direction, and the sixth permanent magnet and the seventh permanent magnet The magnetization directions are opposite.
The electromagnetic exciter according to claim 2, wherein the core post includes an eighth permanent magnet and a ninth permanent magnet arranged side by side perpendicular to the vibration direction, and the eighth permanent magnet and the ninth permanent magnet For relative magnetization.
The electromagnetic exciter according to claim 1, wherein the elastic element comprises an elastic piece, the elastic piece comprising a first connection portion, a second connection portion, and the first connection portion and the second connection portion A spring arm portion between the first connection portion is connected to the housing, and the second connection portion is connected to the vibrator assembly.
The electromagnetic exciter according to claim 7, wherein the casing and the elastic piece form an integrated structure.
The electromagnetic exciter according to claim 7 or 8, wherein the elastic pieces are multiple and are respectively located on an upper side and a lower side of the vibrator component along a vibration direction; or, a plurality of the elastic pieces are located on the The vibrator assembly is on the same side along the vibration direction.
The electromagnetic exciter according to claim 7 or 8, wherein the elastic arm portion is linear or V-shaped.
The electromagnetic exciter according to claim 7 or 8, wherein a boss protruding into the cavity is formed on a shell wall of the housing, and the first connection portion is fixed on the boss, To form a gap between the spring arm portion and the shell wall.
The electromagnetic exciter according to claim 1, wherein the casing is made of a magnetically conductive material.
A screen sounding device, comprising a screen body, a middle frame, and the electromagnetic exciter according to any one of claims 1-12, wherein the electromagnetic exciter is disposed on the screen body or the screen On the middle frame.
The screen sound generating device according to claim 13, further comprising foam rubber, and the electromagnetic actuator is fixedly connected to the screen body or the middle frame through the foam rubber; or,

The electromagnetic actuator is bolted to the screen body or the middle frame.