Miniature loudspeaker with Halbach magnetic circuit

Abstract

The utility model discloses a miniature loudspeaker with a Halbach magnetic circuit. The miniature loudspeaker comprises a shell, the Halbach magnetic circuit, a voice coil, a diaphragm and a protective cover, the shell is provided with a containing cavity, the Halbach magnetic circuit is installed in the containing cavity, and the Halbach magnetic circuit is formed by sequentially arranging an inner ring magnet, a middle radiation ring magnet and an outer ring magnet in a sleeved mode. The diaphragm is installed in the accommodating cavity and located above the Halbach magnetic circuit, and the voice coil is connected to one side of the diaphragm and located above the middle radiation ring magnet; the protective cover is arranged above the diaphragm in a covering manner and is positioned in the accommodating cavity; the magnetic lines of force of the whole Halbach magnetic circuit are guided to the outer ring magnet through the middle radiation ring magnet, so that the bottom magnetic leakage is reduced, the magnetic flux B value of the magnetic circuit is improved to the greatest extent, the BL value performance of the loudspeaker is improved, the frequency response characteristic is improved, and the sensitivity of the loudspeaker is improved.

Description

Technical Field

[0001] The utility model relates to the field of earphone speakers, in particular to a miniature speaker with a Halbach magnetic circuit. Background Art

[0002] A horn, also known as a loudspeaker, is a very common electroacoustic transducer device that can be found in any sound-generating electronic or electrical device. A loudspeaker is a transducer device that converts electrical signals into acoustic signals. The performance of the loudspeaker has a great influence on the sound quality. There are many types of loudspeakers, and their prices vary greatly. Audio electrical energy is transmitted through electromagnetic, piezoelectric or electrostatic effects, causing the cone or diaphragm to vibrate and resonate with the surrounding air to produce sound.

[0003] Existing miniature speakers generally include a bracket, a magnet, a diaphragm and a voice coil. The magnet, diaphragm and voice coil are arranged in the bracket. The voice coil is connected to one end of the diaphragm. The diaphragm is located above the magnet. Due to the influence of the structure of the single magnet itself, the magnetic field at the top of the magnet is higher, while the bottom of the magnet is relatively weak, which makes the speaker seriously distorted.

[0004] Later, a vibration sound-generating device and an electronic product appeared on the market, which include a housing, a fixing part and a driving component; at least a part of the housing is configured to vibrate relative to the fixing part; the driving component includes at least one coil and a Halbach magnet, the coil is fixedly connected to the fixing part, the Halbach magnet is fixedly connected to the housing, or the Halbach magnet is fixedly connected to the fixing part, and the coil is fixedly connected to the housing; the plane where the coil is located is perpendicular to the part of the housing used for vibration, the coil is located on the side of the Halbach magnet, the annular end face of the coil faces the Halbach magnet, and the coil passes through the magnetic field enhancement area of ​​the Halbach magnet; compared with ordinary magnets, the Halbach magnet has a high magnetic field density, a high magnetic field utilization rate, a large driving force, the Ampere force on the coil can be larger and more balanced, the vibration of the vibration component is smoother, stronger, and the vibration start-up speed is faster; however, this kind of dynamic sound-generating device has the following defects:

[0005] For example: the Halbach magnet includes multiple permanent magnets, which are arranged in an array form. The permanent magnets are respectively counted as the first permanent magnet, the second permanent magnet and the third permanent magnet. The coil is sandwiched between the first permanent magnet, the second permanent magnet and the third permanent magnet. A gap is formed between the two groups of permanent magnets, and the coil is located in the gap. Affected by the Halbach magnet array arrangement design, the overall thickness of the vibration sound-generating device increases, making it difficult to obtain a product with a small appearance and thin thickness, and the product miniaturization cannot be met.

[0006] Therefore, it is necessary to study a new technical solution to solve the above problems. Utility Model Content

[0007] In view of this, the utility model aims to solve the deficiencies in the prior art, and its main purpose is to provide a miniature speaker with a Halbach magnetic circuit, which is composed of an inner ring magnet, an intermediate radiation ring magnet and an outer ring magnet to reduce bottom magnetic leakage, increase the magnetic flux of the magnetic circuit, and reduce the height of the magnetic circuit structure, so that the speaker can be made smaller, thinner and less expensive.

[0008] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0009] A miniature speaker with a Halbach magnetic circuit comprises a housing, a Halbach magnetic circuit, a voice coil, a diaphragm and a protective cover; the housing has a containing cavity, the Halbach magnetic circuit is installed in the containing cavity, and the Halbach magnetic circuit is formed by an inner ring magnet, an intermediate radiation ring magnet and an outer ring magnet in sequence; the intermediate radiation ring magnet has an inner ring hole, and the intermediate radiation ring magnet is sleeved outside the inner ring magnet through the inner ring hole; the outer ring magnet has an outer ring hole, and the outer ring magnet is sleeved outside the intermediate radiation ring magnet through the outer ring hole; the inner ring magnet and the outer ring magnet are axial magnets; the intermediate radiation ring magnet is a radial magnet;

[0010] The diaphragm is installed in the accommodating cavity and is located above the Halbach magnetic circuit. The voice coil is connected to one side of the diaphragm and is located above the middle radiation ring magnet. The protective cover is arranged above the diaphragm and is located in the accommodating cavity.

[0011] As a preferred embodiment, the outer shell is also provided with a welding pad for current to flow in and out; the outer shell includes an outer ring wall and an extension portion, and the extension portion is extended outward from the outer ring wall; a clearance opening is opened on the outside of the outer ring wall corresponding to the extension portion, and the welding pad is integrally injection molded on the extension portion.

[0012] As a preferred solution, a gasket is further provided between the diaphragm and the outer ring magnet, and the side of the diaphragm close to the outer ring magnet is located on the gasket; one side of the diaphragm and one side of the outer ring magnet form a vibration space for the diaphragm to vibrate up and down.

[0013] As a preferred solution, one end of the gasket has an escape position, and the escape position is used for allowing the voice coil to extend.

[0014] As a preferred embodiment, the diaphragm includes a middle part and an outer ring part, the outer ring part is arranged around the outer circumference of the middle part, and a diaphragm ring is arranged on one side of the outer ring part; the voice coil is glued to the middle part; the diaphragm divides the accommodating cavity into a front cavity and a rear cavity, and the Halbach magnetic circuit and the voice coil are arranged in the rear cavity; one side of the outer ring part abuts against the gasket.

[0015] As a preferred solution, the outer wall surface of the outer ring magnet is in close contact with the inner wall surface of the accommodating cavity.

[0016] As a preferred solution, the magnetic poles of one end of the outer ring magnet close to the diaphragm and one end of the inner ring magnet close to the voice coil are opposite.

[0017] As a preferred solution, the magnetic pole at one end of the middle radiation ring magnet close to the outer ring magnet is an N pole, and the magnetic pole at one end of the middle radiation ring magnet close to the inner ring magnet is an S pole.

[0018] As a preferred solution, the protective cover has a sound outlet hole connected to the front cavity.

[0019] As a preferred solution, the inner ring magnet, the middle radiation ring magnet and the outer ring magnet are all circular, and the voice coil is flat.

[0020] Compared with the prior art, the utility model has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical scheme that the Halbach magnetic circuit is mainly formed by the inner ring magnet, the middle radiation ring magnet and the outer ring magnet, so that the magnetic lines of force of the whole Halbach magnetic circuit are guided to the outer ring magnet through the middle radiation ring magnet, the bottom magnetic leakage is reduced, the distortion caused by the uneven magnetic field is reduced, the magnetic flux B value of the magnetic circuit is maximized, the BL value performance of the speaker is improved, the frequency response characteristics are improved, and the sensitivity of the speaker is improved; secondly, when the magnetic flux B value of the magnetic circuit is increased, the cost of the speaker is also reduced; and while the magnetic flux B value is guaranteed, the height of the magnetic circuit structure can be reduced, so that the speaker can be made smaller and thinner, which is conducive to the flat design of the product;

[0021] Then, compared with the spliced ​​magnet structure, the leakage magnetic flux is small and there is no need to splice the magnets. It also solves the problem of unevenness between magnets during assembly and reduces the difficulty of operation during speaker production.

[0022] In order to more clearly illustrate the structural features and functions of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional diagram of an embodiment of the utility model;

[0024] Figure 2 It is a cross-sectional view of an embodiment of the utility model;

[0025] Figure 3 It is an exploded view of an embodiment of the utility model;

[0026] Figure 4 It is another exploded view of an embodiment of the utility model;

[0027] Figure 5 It is a magnetic field line diagram of the Halbach magnetic circuit of the embodiment of the utility model;

[0028] Figure 6 It is another magnetic field line diagram of the Halbach magnetic circuit of the embodiment of the utility model;

[0029] Figure 7 It is another magnetic line diagram of the Halbach magnetic circuit of the embodiment of the utility model.

[0030] Description of the accompanying drawings:

[0031] 10. Shell 11. Accommodating cavity

[0032] 111, front cavity 112, back cavity

[0033] 12. Welding pad 13. Outer ring wall

[0034] 121, soldering piece 122, conductive part

[0035] 14. Extension 15. Make way

[0036] 16. Gasket 161. Avoidance

[0037] 20. Halbach magnetic circuit 21. Inner ring magnet

[0038] 22. Middle radiation ring magnet 23. Outer ring magnet

[0039] 221, inner ring hole 231, outer ring hole

[0040] 30. Voice coil 40. Diaphragm

[0041] 41. Middle part 42. Outer ring part

[0042] 43, membrane ring 50, protective cover

[0043] 51. Sound hole. DETAILED DESCRIPTION

[0044] Please refer to Figures 1 to 7 As shown, it shows the specific structure of an embodiment of the utility model.

[0045] In the description of the present invention, it should be noted that directional words such as the terms "up", "down", "front", "back", "left", "right", etc., which indicate directions and positional relationships, are based on the directions or positional relationships shown in the drawings or during normal wearing and use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present invention.

[0046] A miniature speaker with a Halbach magnetic circuit includes a housing 10, a Halbach magnetic circuit 20, a voice coil 30, a diaphragm 40 and a protective cover 50.

[0047] The housing 10 has a receiving cavity 11. Preferably, the housing 10 is also provided with a pad 12 for current to flow in and out.

[0048] The shell 10 includes an outer ring wall 13 and an extension portion 14, and the extension portion 14 is extended outward from the outer ring wall 13; a clearance opening 15 is opened on the outside of the outer ring wall 13 corresponding to the extension portion 14, and the soldering pad 12 is integrally injection-molded on the extension portion 14, and the soldering pad 12 includes a soldering piece portion 121 for connecting to the lead of the voice coil and a conductive portion 122 for electrically connecting to an external component, and the conductive portion 122 extends out of the shell 10. Compared with the traditional welding method between the PCB and the lead of the voice coil 30, the difficulty of welding the lead of the bass coil 30 can be effectively reduced, the work efficiency can be improved, and the defects such as silent welding and short circuit can be reduced. In addition, the existence of the soldering pad 12 can save the need for welding external electronic wires, which can facilitate FPC connection welding.

[0049] The Halbach magnetic circuit 20 is installed in the accommodating cavity 11, and the Halbach magnetic circuit 20 is sequentially formed by an inner ring magnet 21, an intermediate radiation ring magnet 22 and an outer ring magnet 23; preferably, the inner ring magnet 21, the intermediate radiation ring magnet 22 and the outer ring magnet 23 are all circular.

[0050] The intermediate radiation ring magnet 22 has an inner ring hole 221, and the intermediate radiation ring magnet 22 is sleeved on the outside of the inner ring magnet 21 through the inner ring hole 221; the outer ring magnet 23 has an outer ring hole 231, and the outer ring magnet 23 is sleeved on the outside of the intermediate radiation ring magnet 22 through the outer ring hole 231; compared with the spliced ​​magnet structure, the leakage magnetic amount is small and there is no need to splice or bond the magnets, which solves the problem of unevenness between magnets during assembly and reduces the difficulty of operation during speaker production; finally, this type of Halbach magnetic circuit 20 does not require a magnetic conductive plate or T-iron, and its magnetic lines of force are guided to the area of ​​the outer ring magnet 23 through the intermediate radiation ring magnet 22, reducing the bottom leakage magnetic field, so that the speaker sensitivity will be correspondingly improved.

[0051] The inner ring magnet 21 and the outer ring magnet 23 are axial magnets; the middle radiation ring magnet 22 is a radial magnet, which can further increase the strength of the magnetic field, not only avoiding the breakage of the axial magnet during the magnetization process, but also the structure in which the inner ring magnet 21, the middle radiation ring magnet 22 and the outer ring magnet 23 are nested with each other, which is more conducive to the subsequent assembly of the entire magnetic circuit.

[0052] Preferably, the outer wall surface of the outer ring magnet 23 is in close contact with the inner wall surface of the accommodating cavity 11. Preferably, the end of the outer ring magnet 23 close to the diaphragm 40 is opposite to the end of the inner ring magnet 21 close to the voice coil 30. Preferably, the end of the intermediate radiation ring magnet 22 close to the outer ring magnet 23 is an N pole, and the end of the intermediate radiation ring magnet 22 close to the inner ring magnet 21 is an S pole.

[0053] The diaphragm 40 is installed in the accommodating cavity 11 and is located above the Halbach magnetic circuit 20. The voice coil 30 is connected to one side of the diaphragm 40 and is located above the intermediate radiation ring magnet 22. Preferably, the voice coil 30 is flat. The flat voice coil 30 is convenient for installation under the diaphragm 40 and can save the height space of the entire speaker.

[0054] Preferably, a gasket 16 is further provided between the diaphragm 40 and the outer ring magnet 23, and the side of the diaphragm 40 close to the outer ring magnet 23 is located on the gasket 16; one side of the diaphragm 40 and one side of the outer ring magnet 23 form a vibration space for the diaphragm 40 to vibrate up and down. Preferably, one end of the gasket 16 has an escape position 161, and the escape position 161 is used for the voice coil 30 to extend; on the premise of ensuring the accurate positioning of the Halbach magnetic circuit 20, the gasket 16 is provided, and the sound outlet hole 51 at the upper position is matched to expand the space of the front cavity 111 and improve the low-frequency performance.

[0055] Preferably, the diaphragm 40 includes a middle portion 41 and an outer ring portion 42, wherein the outer ring portion 42 is disposed around the outer periphery of the middle portion 41, and a diaphragm ring 43 is disposed on one side of the outer ring portion 42; the diaphragm ring 43 is disposed on the diaphragm 40 to improve low-frequency performance. The diaphragm 40 is flat, which can save the height space of the entire speaker.

[0056] The voice coil 30 is bonded to the middle part 41; the diaphragm 40 divides the accommodating cavity 11 into a front cavity 111 and a rear cavity 112, and the Halbach magnetic circuit 20 and the voice coil 30 are arranged in the rear cavity 112; one side of the outer ring part 42 abuts against the gasket 16. A middle sticker can also be provided on one side of the middle part 41, and the rigidity and symmetry of the central part of the diaphragm 40 are increased through the design of the middle sticker, so as to lay a good foundation for pasting the voice coil 30 below.

[0057] The protective cover 50 is disposed above the diaphragm 40 and is located in the accommodating cavity 11. Preferably, the protective cover 50 has a sound outlet hole 51 connected to the front cavity 111.

[0058] The design focus of the utility model is that it mainly forms a Halbach magnetic circuit through an inner ring magnet, an intermediate radiation ring magnet and an outer ring magnet, so that the magnetic lines of force of the entire Halbach magnetic circuit are guided to the outer ring magnet through the intermediate radiation ring magnet, thereby reducing bottom magnetic leakage, reducing distortion caused by uneven magnetic field, and maximizing the magnetic flux B value of the magnetic circuit, thereby improving the BL value performance of the speaker, improving the frequency response characteristics, and thus improving the sensitivity of the speaker; secondly, when the magnetic flux B value of the magnetic circuit is increased, the cost of the speaker is also reduced; and while the speaker ensures the magnetic flux B value, the height of the magnetic circuit structure can be reduced, so that the speaker can be made smaller and thinner, which is conducive to the flat design of the product;

[0059] Then, compared with the spliced ​​magnet structure, the leakage magnetic flux is small and there is no need to splice the magnets. It also solves the problem of unevenness between magnets during assembly and reduces the difficulty of operation during speaker production.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A miniature speaker with a Halbach magnetic circuit, characterized in that: It comprises a shell, a Halbach magnetic circuit, a voice coil, a diaphragm and a protective cover; the shell has a containing cavity, the Halbach magnetic circuit is installed in the containing cavity, and the Halbach magnetic circuit is formed by an inner ring magnet, an intermediate radiation ring magnet and an outer ring magnet in sequence; the intermediate radiation ring magnet has an inner ring hole, and the intermediate radiation ring magnet is sleeved outside the inner ring magnet through the inner ring hole; the outer ring magnet has an outer ring hole, and the outer ring magnet is sleeved outside the intermediate radiation ring magnet through the outer ring hole; the inner ring magnet and the outer ring magnet are axial magnets; the intermediate radiation ring magnet is a radial magnet; The diaphragm is installed in the accommodating cavity and is located above the Halbach magnetic circuit. The voice coil is connected to one side of the diaphragm and is located above the middle radiation ring magnet. The protective cover is arranged above the diaphragm and is located in the accommodating cavity.

2. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: The shell is also provided with a welding pad for current to flow in and out; the shell includes an outer ring wall and an extension portion, and the extension portion is extended outward from the outer ring wall; a clearance opening is opened on the outside of the outer ring wall corresponding to the extension portion, and the welding pad is integrally injection molded on the extension portion.

3. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: A gasket is also provided between the diaphragm and the outer ring magnet, and the side of the diaphragm close to the outer ring magnet is located on the gasket; one side of the diaphragm and one side of the outer ring magnet form a vibration space for the diaphragm to vibrate up and down.

4. The miniature speaker with Halbach magnetic circuit according to claim 3, characterized in that: One end of the gasket ring is provided with an escape position, and the escape position is used for allowing the voice coil to extend.

5. The miniature speaker with Halbach magnetic circuit according to claim 3, characterized in that: The diaphragm includes a middle part and an outer ring part, the outer ring part is arranged around the outer circumference of the middle part, and a diaphragm ring is arranged on one side of the outer ring part; the voice coil is glued to the middle part; the diaphragm divides the accommodating cavity into a front cavity and a rear cavity, the Halbach magnetic circuit and the voice coil are arranged in the rear cavity; one side of the outer ring part abuts against the gasket.

6. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: The outer wall surface of the outer ring magnet is in close contact with the inner wall surface of the accommodating cavity.

7. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: The magnetic poles of one end of the outer ring magnet close to the diaphragm and one end of the inner ring magnet close to the voice coil are opposite.

8. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: The magnetic pole of one end of the middle radiation ring magnet close to the outer ring magnet is an N pole, and the magnetic pole of one end of the middle radiation ring magnet close to the inner ring magnet is an S pole.

9. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: The protective cover is provided with a sound outlet hole connected to the front cavity.

10. The miniature speaker with Halbach magnetic circuit according to claim 1, characterized in that: The inner ring magnet, the middle radiation ring magnet and the outer ring magnet are all circular, and the voice coil is flat.

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