WO2018119895A1 - 一种磁路系统及其制造方法、微型扬声器 - Google Patents

一种磁路系统及其制造方法、微型扬声器 Download PDF

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Publication number
WO2018119895A1
WO2018119895A1 PCT/CN2016/113073 CN2016113073W WO2018119895A1 WO 2018119895 A1 WO2018119895 A1 WO 2018119895A1 CN 2016113073 W CN2016113073 W CN 2016113073W WO 2018119895 A1 WO2018119895 A1 WO 2018119895A1
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WO
WIPO (PCT)
Prior art keywords
yoke
magnetic
central
magnetic gap
topsheet
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PCT/CN2016/113073
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English (en)
French (fr)
Inventor
刘振普
季文晖
Original Assignee
奥音科技（北京）有限公司
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Application filed by 奥音科技（北京）有限公司 filed Critical 奥音科技（北京）有限公司
Priority to PCT/CN2016/113073 priority Critical patent/WO2018119895A1/zh
Publication of WO2018119895A1 publication Critical patent/WO2018119895A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02—Details
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/06—Loudspeakers

Definitions

  • the present invention relates to the field of speaker technologies, and in particular, to a magnetic circuit system, a method of manufacturing the same, and a microspeaker.
  • the structure of the speaker generally includes three parts: a magnetic circuit system, a vibration system and a fixed system; the magnetic circuit system mainly comprises a magnet, a yoke and a washer (top sheet), and the three are surrounded by a toroidal magnetic gap, and a uniform magnetic field is filled therebetween.
  • the vibration system mainly comprises a voice coil disposed in the annular magnetic gap and a diaphragm integrally provided with the voice coil; the fixing system comprises a basin frame or the like for fixedly mounting the magnetic circuit system and the vibration system.
  • the voice coil acquires an electrical signal
  • the magnetic field line is cut in the magnetic field, and the magnetic field oscillates in the annular magnetic gap, thereby causing the diaphragm to oscillate, thereby emitting a corresponding sound.
  • the following three technical means are often employed.
  • the first is to use a multi-layer composite diaphragm to improve the damping.
  • the disadvantage is that the damping provided by this method is relatively small, the effect is limited, and it is difficult to achieve the best effect; the second is to add on the diaphragm.
  • Damping glue the disadvantage is that the damping rubber has a certain fluidity, and will be lost under long-term or high-temperature conditions; the third is to install a low-breathing damping net, the disadvantage is that due to the limited mesh type, It is only possible to roughly adjust the amplitude of the diaphragm, and it is difficult to make precise adjustments, and the bonding of the damping net requires a special process and the production cost is high.
  • the micro-speaker of the prior art has a small volume, and the inner voice coil easily collides with the magnetic circuit system, and the diaphragm of the prior art is prone to roll-pulsing phenomenon, thereby causing a large noise of the speaker.
  • Smart PA Smart PA
  • the demand for high-power micro-speakers is increasing.
  • air acts as a heat-dissipating medium around the voice coil, and the heat-dissipating ability is poor, and can only withstand a small working current; when the working current is large, the voice coil is burnt due to overheating, and cannot withstand High power operating current.
  • the magnetic circuit system provides a relatively small magnetic field strength, and the working current is relatively small.
  • the voice coil is easy to collide with the magnetic circuit system, and the diaphragm is prone to rolling vibration, so the sound quality and volume are relatively poor.
  • the material quality and processing precision of the magnetic circuit system and the vibration system can be improved, which greatly increases the production cost, and the high-quality micro-speaker is expensive, which is not conducive to market promotion.
  • Magnetic fluid also known as magnetic liquid, ferrofluid or magnetic fluid
  • magnetic fluid is a kind of stable glue which is made up of magnetic solid particles, base carrier liquid and surfactant which are of nanometer order (9 nm or less) in diameter. Liquid.
  • the magnetic fluid has no magnetic attraction when it is static. When it is applied by a magnetic field, it exhibits magnetism. Under the action of the magnetic field, it can be automatically positioned without flowing around.
  • magnetic fluid technology has been applied to the field of large-sized speakers, and the magnetic fluid is placed in the gap between the voice coil and the magnetic gap of the speaker, which can effectively improve the performance of the speaker.
  • the present invention provides a magnetic circuit system including a toroidal magnetic gap, two or more low magnetic field nodes, a magnetic gap region, and a magnetic fluid; the annular magnetic gap is surrounded by a yoke, a magnet, and a top sheet; The low magnetic field node is disposed in the annular magnetic gap; the magnetic gap region is a portion between any two low magnetic field nodes in the annular magnetic gap; the magnetic fluid is filled in at least one magnetic gap region .
  • the yoke includes a yoke bottom plate and a yoke side plate; the yoke side plate is disposed at an edge of the yoke bottom plate.
  • the magnet includes a central magnet and/or an edge magnet attached to a middle portion of an upper surface of the yoke bottom plate; the side magnet is attached to the yoke bottom plate At the edge of the upper surface.
  • the topsheet comprises a central topsheet and/or a topsheet, the central topsheet being attached to the upper surface of the central magnet; the topsheet being attached to the side The upper surface of the magnet.
  • the low magnetic field node includes more than two central topsheet notches and/or two or more side topsheet notches and/or two or more yoke grooves, the central topsheet notch is provided At the edge of the central topsheet, the opening direction thereof faces the annular magnetic gap; the edge top sheet notch is disposed at the edge of the edge top sheet, and the opening direction thereof faces the annular magnetic gap; the yoke concave The groove is disposed on the side end of the yoke side.
  • each central topsheet notch is positioned with a side topsheet notch And/or the positions of one yoke groove correspond to each other.
  • the yoke includes a yoke bottom plate.
  • the magnet includes a central magnet attached to a middle portion of an upper surface of the yoke bottom plate, and a side magnet attached to an upper surface of the yoke bottom plate At the edge of the.
  • the topsheet comprises a central topsheet and a side topsheet, the central topsheet being attached to the upper surface of the central magnet;
  • the side top sheet is attached to the upper surface of the side magnet.
  • the low magnetic field node includes more than two central topsheet notches and/or two or more side topsheet notches, the central topsheet notch being disposed at the edge of the central topsheet, The opening direction faces the annular magnetic gap; the side top sheet notch is disposed at the edge of the side top sheet, and the opening direction thereof faces the annular magnetic gap.
  • the position of each central topsheet notch corresponds to the position of one of the side topsheet notches.
  • the magnetic gap region filled with the magnetic fluid is an axisymmetric pattern whose axis of symmetry is a center line of the annular magnetic gap.
  • the present invention also provides a microspeaker comprising any of the magnetic circuit systems described above.
  • the microspeaker further includes a voice coil disposed in the annular magnetic gap; the magnetic fluid is filled on both sides of the voice coil and/or a bottom thereof; the magnetic fluid is stuck Attached to the yoke and/or the magnet and/or the edge of the topsheet.
  • the microspeaker includes, but is not limited to, a flat diaphragm speaker, a conical diaphragm speaker, or a dome shaped speaker.
  • the present invention also provides a method for manufacturing the magnetic circuit system, comprising the steps of: enclosing a magnet, a yoke and a top sheet into a toroidal magnetic gap; and setting two or more in the annular magnetic gap.
  • a low magnetic field node, a portion between any two low magnetic field nodes in the annular magnetic gap forms a magnetic gap region; and at least one magnetic gap region is filled with magnetic fluid.
  • the step of enclosing the yoke, the magnet and the top sheet into an annular magnetic gap comprises the steps of: providing a yoke side plate at an edge of the upper surface of the yoke bottom plate of the yoke; A central magnet is attached to a central portion of the upper surface of the yoke bottom plate of the yoke; and a central top sheet is attached to the upper surface of the central magnet.
  • the step of providing two or more low magnetic field nodes in the annular magnetic gap includes the steps of: providing more than two central topsheet notches at the edge of the central topsheet, the opening direction thereof Facing the annular magnetic gap; and/or providing more than two yoke grooves on the yoke side plate end.
  • the step of enclosing the magnet, the yoke and the top sheet into the annular magnetic gap further comprises the step of attaching at least one set at the edge of the upper surface of the yoke bottom plate of the yoke Side magnets facing each other; a top sheet is attached to the upper surface of the side magnet.
  • the step of providing two or more low magnetic field nodes in the annular magnetic gap includes the steps of: providing more than two central topsheet notches at the edge of the central topsheet, the opening direction thereof Facing the annular magnetic gap; and/or providing two or more side top sheet notches at the edge of the side panel, the opening direction of which faces the annular magnetic gap; and/or two of the yoke side ends More than one yoke groove.
  • the step of enclosing the magnet, the yoke and the top sheet into an annular magnetic gap comprises the steps of: attaching a central magnet to a middle portion of the upper surface of the yoke bottom plate of the yoke; At least one set of side magnets facing each other is attached to an edge of the upper surface of the yoke bottom plate of the yoke; a central top sheet is attached to the upper surface of the central magnet, and a top sheet is attached to the upper surface of the side magnet.
  • the step of providing two or more low magnetic field nodes in the annular magnetic gap includes the steps of: providing more than two central topsheet notches at the edge of the central topsheet, the opening direction thereof Facing the annular magnetic gap; and/or providing more than two side topsheet notches at the edge of the side panel, the opening direction of which faces the annular magnetic gap.
  • An advantage of the present invention is that the present invention provides a magnetic circuit system and a method of fabricating the same, and a microspeaker that can apply magnetic fluid technology to a microspeaker to divide the annular magnetic gap in the magnetic circuit system into a plurality of mutual
  • the separated part is only filled with magnetic fluid in one or several of the parts, instead of filling the entire annular magnetic gap with the magnetic fluid, so that only a part of the voice coil is affected by the viscous force of the magnetic fluid, thereby appropriately increasing the voice coil damping.
  • the magnetic coil technology can also be applied to the micro-speaker to improve the magnetic field strength, improve the heat dissipation condition of the voice coil, and reduce the friction yoke of the voice coil, thereby improving the performance of the speaker. More importantly, the length of the magnetic gap region and the amount of magnetic fluid filling can be automatically adjusted by the designer as needed to achieve precise control of the voice coil damping/diaphragm damping.
  • FIG. 1 is a schematic exploded perspective view of a microspeaker according to Embodiment 1 of the present invention.
  • FIG. 2 is a schematic view showing the overall structure of a magnetic circuit system according to Embodiment 1 of the present invention.
  • FIG. 3 is a top plan view of a magnetic circuit system according to Embodiment 1 of the present invention.
  • FIG. 4 is a top structural view showing a voice coil and a magnetic fluid added to a magnetic circuit system according to Embodiment 1 of the present invention
  • FIG. 5 is a schematic exploded view of a microspeaker according to a modified embodiment 1 of the present invention.
  • FIG. 6 is a schematic view showing the overall structure of a magnetic circuit system according to a modified embodiment 1 of the present invention.
  • FIG. 7 is a flowchart of a method of manufacturing a magnetic circuit system according to Embodiment 1-3 of the present invention.
  • FIG. 8 is a flow chart of a method for enclosing a toroidal magnetic gap in Embodiment 1 of the present invention.
  • FIG. 9 is a schematic overall structural diagram of a magnetic circuit system according to Embodiment 2 of the present invention.
  • FIG. 10 is a schematic exploded view of a magnetic circuit system according to Embodiment 2 of the present invention.
  • FIG. 11 is a flow chart of a method for enclosing a toroidal magnetic gap according to Embodiment 2 of the present invention.
  • FIG. 12 is a schematic overall structural diagram of a magnetic circuit system according to Embodiment 3 of the present invention.
  • FIG. 13 is a schematic exploded view of a magnetic circuit system according to Embodiment 3 of the present invention.
  • FIG. 14 is a flow chart of a method of enclosing a toroidal magnetic gap in Embodiment 3 of the present invention.
  • 901 first axis of symmetry 902 second axis of symmetry.
  • a component When a component is described as being “on” another component, the component can be placed directly on the other component; an intermediate component can also be present, the component being placed on the intermediate component, And the intermediate part is placed on another part.
  • an intermediate component can also be present, the component being placed on the intermediate component, And the intermediate part is placed on another part.
  • a component is described as “mounted to” or “connected to” another component, both can be understood as direct “installation.” Or “connected”, or a component is “mounted” or “connected” to another component indirectly through an intermediate component.
  • Embodiment 1 exemplifies a structure of the present invention by taking a single magnetic circuit flat diaphragm speaker as an example.
  • the micro-speaker of this embodiment may also be other types of speakers, and further includes a conical diaphragm speaker or a dome-shaped speaker, and the like.
  • the microspeaker of Embodiment 1 includes a yoke 1, a central magnet 2, a center topsheet 3, a voice coil 4, a diaphragm 5, and a basin holder 6.
  • the magnetic circuit system of the microspeaker of the present embodiment mainly includes a yoke 1, a central magnet 2, and a central topsheet 3.
  • the yoke 1 includes a yoke bottom plate 11 and a yoke side plate 12, and the yoke side plate 12 is provided at the edge of the yoke bottom plate 11; the yoke side plate 12 and the yoke
  • the bottom plate 11 encloses a yoke basin 13.
  • Yoke 1 The magnetic field (magnetic line) is not generated by itself, and only magnetic lines are transmitted in the magnetic circuit system, and soft magnetic materials such as soft iron or soft magnetic alloy with relatively high magnetic permeability are generally used.
  • the yoke side plates 12 are uniformly and symmetrically distributed around the voice coil 4, and the magnetic flux leakage of the voice coil 4 is restricted to spread outward, thereby improving the efficiency of the induction intervention.
  • the yoke bottom plate 11 is rectangular
  • the yoke side plate 12 is four rectangular plates which are connected end to end, and are respectively disposed on four sides of the yoke bottom plate 11, and may be provided at the connection of two adjacent rectangular plates. Small side panel gap.
  • the yoke 1 may have other shapes, such as a circular shape, in which case the yoke base plate 11 is circular, and the yoke side plate 12 is a non-notched ring.
  • the central magnet 2 is disposed in the yoke cavity 13 and attached to the middle of the upper surface of the yoke base plate 11, but the central magnet 2 and the yoke side plate 12 are not in direct contact, but remain separated, leaving sufficient for both. gap.
  • the center top sheet 3 is attached to the upper surface of the center magnet 2, and the center top sheet 3 corresponds to the shape and size of the center magnet 2.
  • the central topsheet 3, the central magnet 2 and the yoke 1 enclose an annular magnetic gap 7, also referred to as an annular magnetic gap or a magnetic gap.
  • the annular magnetic gap 7 is covered with a uniform magnetic field, and the magnetic induction intensity in the magnetic field is the same as the direction.
  • the voice coil 4 is disposed in the annular magnetic gap 7. After the voice coil 4 acquires an electrical signal, the magnetic field line is cut in the magnetic field, and vibrates (oscillates) up and down in the annular magnetic gap 7.
  • the diaphragm 5 is disposed above the voice coil 4 and the center top sheet 3, and is connected to the voice coil 4.
  • the diaphragm 5 in this embodiment is a sunken diaphragm, and the voice coil 4 receives electrical signals of different frequencies, and physical vibration occurs at different frequencies, and the air medium around the diaphragm 5 cooperates with the diaphragm 5 to emit The sound of different frequencies, the whole process of speaker sound is the conversion process of electricity, force and sound.
  • the microspeaker of Embodiment 1 further includes a basin holder 6 to which the yoke 1 is fixedly mounted, and the diaphragm 5 is fixedly coupled to the top of the basin frame 6, so that the various components of the speaker are integrally formed.
  • two or more low magnetic field nodes 8, preferably four or eight, are disposed in the annular magnetic gap 7, and a portion between any two low magnetic field nodes 8 in the annular magnetic gap 7 forms a magnetic gap region 9, At least one of the magnetic gap regions 9 is filled with a magnetic fluid 10.
  • each low magnetic field node 8 may include a central topsheet notch 81 and/or a yoke recess 82.
  • Two or more central topsheet notches 81 are provided at the edge of the central topsheet 3, the opening direction of which faces the annular magnetic gap 7, the central topsheet 3 is in close contact with the central magnet 2, and the central topsheet notch 81 is exposed centrally. A part of the magnet 2. In the portion of the annular magnetic gap 7 that faces the central topsheet notch 81, the magnetic field density decreases, forming a low magnetic field strength region, which may be referred to as a "low magnetic field trap.”
  • the upper end of the yoke side plate 12 is provided with two or more yoke grooves 82, preferably four. In the portion of the annular magnetic gap 7 that faces the yoke groove 82, the magnetic field density decreases, and a low magnetic field strength region is formed.
  • Embodiment 1 only the central top sheet notch 81 or the yoke groove 82 may be selected as the low magnetic field node, or the central top sheet notch 81 and the yoke groove 82 may be simultaneously used as the low magnetic field node.
  • the position of the sheet notch 81 corresponds to the position of a yoke groove 82.
  • the annular magnetic gap 7 is divided into a plurality of magnetic gap portions by two or more low magnetic field nodes 8, and a magnetic gap portion between any two adjacent low magnetic field nodes 8 forms a small magnetic gap region 9.
  • the four low magnetic field nodes 8 divide the annular magnetic gap 7 into four magnetic gap regions 9, including a first magnetic gap region 91, a second magnetic gap region 92, a third magnetic gap region 93, and a fourth magnetic gap region.
  • the first magnetic gap region 91 and the third magnetic gap region 93 opposite to each other are equal in length; the second magnetic gap region 92 and the fourth magnetic gap region 94 opposed to each other are equal in length.
  • the length of the magnetic gap region filling the magnetic fluid 10 affects the damping of the voice coil of the speaker.
  • the magnetic fluid 10 is filled in one or more small magnetic gap regions, and as shown in FIG. 4, preferably, the magnetic fluid is filled in the first magnetic gap region 91 and the third magnetic gap region 93.
  • the magnetic fluid 10 itself has magnetic properties. Since both ends of the small magnetic gap region are low magnetic field strength regions, when the magnetic fluid 10 flows to a low magnetic field strength region, the magnetic fluid 10 is subjected to a certain repulsive force, making it difficult for the magnetic fluid 10 to pass through the low.
  • the magnetic field strength region flows to other portions of the annular magnetic gap 7.
  • the magnetic fluid 10 and the yoke 1, the central magnet 2, and the central topsheet 3 together form a magnetic circuit system, which can further enhance the magnetic field strength in the first magnetic gap region 91 and the third magnetic gap region 93, and improve the sound quality of the speaker.
  • the central top sheet notch 81 has a semicircular or arcuate cross section, which facilitates calculation of magnetic field strength and drawing of magnetic lines of force.
  • the cross-sectional diameter of the central topsheet notch 81 is 30% ⁇ 200% of the thickness of the central topsheet 3.
  • the cross-sectional diameter is calculated and adjusted by the designer according to the needs.
  • Various parameters such as the magnetic of the central magnet are needed in the calculation process. Media parameters, magnetic media parameters of magnetic fluid, voice coil quality, etc.
  • many magnetic fluid materials can reduce fluidity and become a semi-solidified gel in high temperature and high magnetic environments.
  • the magnetic fluid 10 is filled in one or several small magnetic gap regions in the annular magnetic gap 7, specifically, the magnetic fluid 10 is filled in the yoke 1 and the central magnet 2 In the gap between the center topsheet 3 and the voice coil 4, the magnetic fluid 10 is thus filled on both sides of the voice coil 4 and/or its bottom, and is attached to the edges of the yoke 1 and/or the center topsheet 3.
  • the voice coil 4 is filled with the magnetic fluid 10 on both sides. If only the central top sheet notch 81 is provided as the low magnetic field node 8, the magnetic fluid 10 near the central topsheet 3 side is subjected to a large repulsive force, and the other side The magnetic fluid 10 is less repulsive and may cause leakage of the magnetic fluid 10. Similarly, if only the yoke groove 82 is provided as the low magnetic field node 8, the magnetic fluid 10 on the side close to the yoke side plate 12 is subjected to a large repulsive force, and the magnetic fluid 10 on the other side is subjected to a small repulsive force, which may cause magnetic Leakage of fluid 10. In order to subject the magnetic fluid 10 on both sides of the voice coil 4 to the same or similar repulsive force, it is preferable to use the central top sheet notch 81 and the yoke groove 82 simultaneously as a low magnetic field node.
  • the magnetic fluid 10 adheres to the voice coil 4, and since the magnetic fluid 10 itself has a viscous force, the damping of the voice coil 4 and the diaphragm 5 can be increased to some extent.
  • the damping of the magnetic fluid 10 in a small magnetic gap is determined by the amount of magnetic fluid 10 in the annular magnetic gap 7, which can be said to be determined by the distance between the two central topsheet notches 81,
  • the spacing of adjacent low magnetic field nodes is proportional to the amount of magnetic fluid used.
  • the distance between any two central topsheet notches 81 is 30% ⁇ 80% of the length of the central topsheet 3.
  • the specific value of the distance can be calculated and adjusted by the designer according to the needs, and needs to be referenced in the calculation process.
  • Various parameters such as magnetic medium parameters of different types of magnetic fluid 10, voice coil quality parameters, annular magnetic gap width, and the like.
  • any one of the magnetic gap regions filled with the magnetic fluid 10 is an axisymmetric pattern whose axis of symmetry is a center line of the annular magnetic gap 9.
  • the magnetic gap regions filled with the magnetic fluid 10 are generally present in pairs, and a pair of opposite magnetic gap regions are symmetric with respect to a center line of the annular magnetic gap 9, thereby ensuring force balance on both sides or sides of the voice coil. If there is only one magnetic gap region filling the magnetic fluid 10, the one side of the voice coil is inevitably biased, so that the voice coil cannot vibrate normally.
  • the first magnetic gap region 91 and the third magnetic gap region 93 are filled with the magnetic fluid 10, and the first magnetic gap region 91 and the third magnetic gap region 93 are all axisymmetric.
  • the axis of symmetry is a center line of the annular magnetic gap 9, which may be referred to as a first axis of symmetry 901, the first magnetic gap region 91, the low magnetic field node 8 at both ends of the third magnetic gap region 93 to the first axis of symmetry 901 The distance is equal.
  • the first magnetic gap region 91 and the third magnetic gap region 93 are symmetric with respect to the other center line of the annular magnetic gap 9, and the center line may be referred to as the second symmetry axis 902.
  • the voice coil 4 is affected by the viscous force of the magnetic fluid 10 of the same magnitude in the opposite directions, so that the damping balance of the voice coil 4 can be achieved, so that the voice coil 4 can smoothly vibrate after being energized without tilting.
  • Embodiment 1 can be further improved.
  • the modified embodiment 1 can include eight low magnetic field nodes 8, each of which can include a central topsheet notch 81 and / Or the yoke groove 82, the working principle and technical effect are similar to those of the four low magnetic field nodes, and will not be described herein.
  • the magnetic field strength is generally weak, and in order to increase the magnetic field strength, only the method of reducing the distance between the central topsheet 3 and the yoke 1 can be employed.
  • the disadvantage is that this method requires a high degree of assembly processing and greatly increases the processing cost.
  • the magnetic circuit system (including the yoke 1, the central magnet 2, the central topsheet 3, and the magnetic fluid 10) can provide a higher magnetic field strength and can be better adjusted.
  • the Q value of the speaker improves the transient response speed and helps improve the frequency response of the speaker.
  • the microspeaker of the prior art has a very thin diaphragm, and a slight imbalance causes a rolling vibration, causing the voice coil 4 to collide with components of the magnetic circuit system (such as the yoke 1, the central magnet 2 or the central topsheet 3), thereby Produces noise.
  • the voice coil can be suspended to realize automatic positioning.
  • the magnetic fluid 10 isolates the voice coil 4 from the yoke 1 so that when the voice coil 4 oscillates, the occurrence of the voice coil friction yoke phenomenon can be reduced, and the distortion of the speaker, particularly the harmonic distortion, can be reduced.
  • Prior art microspeakers have an increasing demand for input power, so that the heat generated in the operation of the speaker will also become larger and larger. Due to the small size of the micro-speaker and the poor thermal conductivity of the air medium, the heat dissipation capability of the voice coil is poor, and it is easy to cause thermal damage of the speaker due to the high temperature of the voice coil. In this embodiment, since the thermal conductivity of the magnetic fluid is more than 6 times that of the air medium, the heat dissipation effect of the voice coil can be effectively improved, and the heat loss of the speaker due to overheating of the voice coil can be avoided.
  • the micro-speaker of this embodiment can withstand greater input power, and can make the input power of the micro-speaker more than twice the original input power.
  • Embodiment 1 further provides a method of manufacturing a magnetic circuit system as described above, comprising the following steps S1) to S3).
  • Step S1) enclosing the magnet, the yoke and the top sheet into a toroidal magnetic gap.
  • step S1) specifically includes: step S101) a yoke side plate is disposed at an edge of the upper surface of the yoke bottom plate of the yoke; a step S102) attaching a central magnet to a middle portion of the upper surface of the yoke bottom plate of the yoke; and step S103) on the central magnet The center top piece is attached to the surface.
  • Step S2) providing two or more low magnetic field nodes in the annular magnetic gap such that a portion between any two low magnetic field nodes in the annular magnetic gap forms a magnetic gap region.
  • two or more central topsheet notches are provided at the edge of the central topsheet, the opening direction of which faces the annular magnetic gap; and/or two or more yoke recesses are provided at the yoke side end of the yoke .
  • step S2) before setting the low magnetic field node, it is necessary to calculate the amount of magnetic fluid, calculate the position of the low magnetic field node; and also calculate the size of the central topsheet notch and/or the yoke groove, two adjacent The spacing between the low magnetic field nodes is proportional to the amount of magnetic fluid.
  • Step S3) filling the at least one magnetic gap region with magnetic fluid to complete the assembly of the magnetic circuit system.
  • step S1) to step S3) components such as the voice coil 4, the diaphragm 5, the basin frame 6, and the magnetic circuit system are assembled, and a microspeaker can be produced.
  • the position of the low magnetic field node can be set as needed, and the amount of magnetic fluid in the magnetic circuit system can be adjusted by itself, thereby effectively adjusting the damping of the voice coil and the diaphragm.
  • the advantage of this embodiment is that the damping of the voice coil and the diaphragm can be properly adjusted in the embodiment, and the magnetic circuit system can provide higher magnetic field strength, better adjust the Q value of the speaker, improve the transient response speed, and is beneficial to improvement.
  • the frequency response of the speaker When the voice coil oscillates, this embodiment can reduce the occurrence of the voice coil friction yoke phenomenon, thereby reducing the distortion of the speaker, especially the harmonic distortion, and effectively improving the sound quality of the speaker. In this embodiment, the heat dissipation effect of the voice coil can be effectively improved, and the heat loss of the speaker caused by the overheating of the voice coil can be avoided.
  • the micro-speaker of this embodiment can withstand greater input power, and can make the input power of the micro-speaker more than twice the original input power.
  • Embodiment 2 provides another type of microspeaker, the technical solution of which is mostly the same as that of Embodiment 1, and the distinguishing feature is that the magnetic circuit system of the microspeaker of Embodiment 2 is different from the magnetic circuit system of Embodiment 1.
  • the magnetic circuit system of the microspeaker of the present embodiment mainly includes a yoke 1, a central magnet 2, a central topsheet 3, a side magnet 21, and a side top sheet 22.
  • the yoke 1 includes a rectangular yoke base plate 11 on which a pair of opposite sides are provided with two opposite yoke side plates 12, and the other pair of opposite sides are provided with two Side magnets 21.
  • Two yoke side plates 12 are disposed at the edge of the yoke bottom plate 11, and the two opposite yoke side plates 12 do not generate a magnetic field by themselves, and only magnetic field lines are transmitted in the magnetic circuit system, generally using a soft magnetic material, such as a guide. Soft iron or soft magnetic alloy with high magnetic permeability.
  • the embodiment is a three-magnetic circuit design comprising a central magnet 2 and two side magnets 21 attached to the central portion of the upper surface of the yoke base plate 11, and two side magnets 21 attached to the yoke base plate 11 At the edge of the upper surface, the central magnet 2 and the two side magnets 21 are made of the same magnetic medium, which together form a magnetic field in the magnetic circuit system.
  • the central magnet 2 is not in direct contact with the two side magnets 21 and the yoke side plates 12, but remains separated, leaving a sufficient gap.
  • the center top sheet 3 is attached to the upper surface of the center magnet 2, and the center top sheet 3 corresponds to the shape and size of the center magnet 2.
  • the four side top sheets 22 are attached to the upper surfaces of the four side magnets 21, and each side top sheet 22 corresponds to the shape and size of the lower side magnets 21.
  • the yoke 1, the central magnet 2, the central topsheet 3, the side magnets 21 and the side topsheet 22 enclose an annular magnetic gap 7, also referred to as an annular magnetic gap or a magnetic gap.
  • the annular magnetic gap 7 is covered with a uniform magnetic field, and the magnetic induction intensity in the magnetic field is the same as the direction.
  • two or more low magnetic field nodes 8 are disposed in the annular magnetic gap 7, and a portion between any two low magnetic field nodes 8 in the annular magnetic gap 7 forms a magnetic gap region 9, at least one of the magnetic gap regions 9 It is filled with a magnetic fluid 10.
  • the low magnetic field node 8 can include a central topsheet notch 81 and/or a yoke recess 82 and/or a side topsheet notch 83.
  • Two or more central topsheet notches 81 are provided at the edge of the central topsheet 3, the opening direction of which faces the annular magnetic gap 7, preferably eight in the embodiment, and two central tops on the four sides of the central topsheet 3, respectively.
  • the central topsheet 3 is in close contact with the central magnet 2, and a portion of the central magnet 2 is exposed at the central topsheet notch 81.
  • the magnetic field density decreases, forming a low magnetic field strength region, which may be referred to as a "low magnetic field trap.”
  • Two or more yoke grooves 82 are provided at the upper end of the yoke side plate 12, and preferably four in the embodiment, corresponding to four central top plate notches 81, respectively.
  • the magnetic field density decreases, and a low magnetic field strength region, that is, a "low magnetic field trap" is formed.
  • Two or more top sheet notches 83 are provided at the edge of the side top sheet 22, and the opening direction thereof faces the annular magnetic gap 7, preferably four in the embodiment, corresponding to four central top sheet notches 81, respectively.
  • the side top sheet 22 is in close contact with the side magnet 21, and a part of the side magnet 21 is exposed at the top sheet notch 83.
  • the magnetic field density decreases, forming a region of low magnetic field strength, a "low magnetic field trap.”
  • the low magnetic field node may select only one of the central top sheet notch 81 or the yoke groove 82 or the side top sheet notch 83, or two or three of them may be used at the same time.
  • the position of a central topsheet notch 81 corresponds to the position of a yoke recess 82 and/or a topsheet notch 83.
  • a micro-speaker is manufactured by using the magnetic circuit system of the embodiment, and the voice coil is disposed in the annular magnetic gap 7, and magnetic fluid (not shown) is filled on both sides of the voice coil and/or the bottom thereof. If only one of the central top sheet notch 81 or the yoke groove 82 or the side top sheet notch 83 is selected, the magnetic fluid on both sides of the voice coil is repulsively different in size, which may cause leakage of the magnetic fluid. In order to subject the magnetic fluids on both sides of the voice coil to the same or similar magnitude of repulsive force, it is preferred to use both the central topsheet notch 81 and the yoke recess 82 and/or the topsheet notch 83 as low magnetic field nodes.
  • the annular magnetic gap 7 is divided into eight magnetic gap portions by eight low magnetic field nodes 8, and a magnetic gap portion 9 between any two adjacent low magnetic field nodes 8 forms a small magnetic gap region 9.
  • the magnetic flux can be filled in the four magnetic gap regions 9 located in the middle of the four sides of the rectangular annular magnetic gap 7, or the magnetic fluid can be filled in the two opposite magnetic gap regions 9.
  • the magnetic fluid itself has magnetic properties. Since both ends of the small magnetic gap region are low magnetic field strength regions, when the magnetic fluid flows to a low magnetic field strength region, the magnetic fluid is subjected to a certain repulsive force, making it difficult for the magnetic fluid to pass through the low magnetic field strength region. It flows to other parts of the annular magnetic gap 7.
  • the magnetic fluid and the yoke 1, the central magnet 2, the central topsheet 3, the side magnets 21 and the side topsheet 22 together form a magnetic circuit system, which can further enhance the magnetic field strength in the four magnetic gap regions 9 and improve the sound quality of the speaker.
  • the three magnets and the magnetic flux region filled with the magnetic fluid in Embodiment 2 can provide higher magnetic field strength, better adjust the Q value of the speaker, and improve the transient response speed, which is beneficial to improvement.
  • the frequency response of the speaker is beneficial to improvement.
  • Other technical effects of the magnetic fluid in Embodiment 2 are the same as or similar to those of the magnetic fluid in Embodiment 1, and are not described herein.
  • Embodiment 2 also provides a method of manufacturing a magnetic circuit system as described above, and as shown in FIG. 7, includes the following steps S1) to S3).
  • Step S1) enclosing the magnet, the yoke and the top sheet into a toroidal magnetic gap.
  • step S1) specifically includes the following steps: step S111) providing at least one set of yoke side plates opposite to each other at an edge of the upper surface of the yoke bottom plate of the yoke, adjacent two yokes Forming a side plate gap between the side plates; step S112) attaching a central magnet to a middle portion of the upper surface of the yoke bottom plate of the yoke; and step S113) attaching at least an edge of the upper surface of the yoke bottom plate of the yoke a pair of side magnets facing each other, the side magnets are disposed at the gaps of the side plates; step S114) attaching a central top sheet to the upper surface of the central magnet, and attaching a top sheet to the upper surface of the side magnets .
  • Step S2) providing two or more low magnetic field nodes in the annular magnetic gap such that a portion between any two low magnetic field nodes in the annular magnetic gap forms a magnetic gap region.
  • two or more central topsheet notches are provided at the edge of the central topsheet, the opening direction of which faces the annular magnetic gap; and/or two or more topsheets are provided at the edge of the sidesheet a notch whose opening direction faces the annular magnetic gap; and/or two or more yoke grooves are provided at the yoke side plate end.
  • step S2 before setting the low magnetic field node, it is necessary to calculate the amount of magnetic fluid, calculate the position of the low magnetic field node; and also calculate the central top sheet notch and/or the side top sheet notch and/or the yoke The size of the groove.
  • Step S3) filling the at least one magnetic gap region with magnetic fluid to complete the assembly of the magnetic circuit system.
  • step S1) to step S3) components such as the voice coil 4, the diaphragm 5, the basin frame 6, and the magnetic circuit system of the present embodiment are assembled, that is, a microspeaker can be produced.
  • the position of the low magnetic field node can be set as needed, and the amount of magnetic fluid in the magnetic circuit system can be adjusted by itself, thereby effectively adjusting the damping of the voice coil and the diaphragm.
  • the advantage of this embodiment is that, compared with Embodiment 1, the three magnets and the magnetic flux region filled with the magnetic fluid in the embodiment can provide higher magnetic field strength, better adjust the Q value of the speaker, and improve the transient state.
  • the response speed helps improve the frequency response of the speaker.
  • this embodiment can reduce the occurrence of the voice coil friction yoke phenomenon, thereby reducing the distortion of the speaker, especially the harmonic distortion, and effectively improving the sound quality of the speaker.
  • the heat dissipation effect of the voice coil can be effectively improved, and the heat loss of the speaker caused by the overheating of the voice coil can be avoided.
  • the micro-speaker of this embodiment can withstand greater input power, and can make the input power of the micro-speaker more than twice the original input power.
  • the third embodiment provides another micro-speaker, and the technical solution is mostly the same as that of the first embodiment, and the distinguishing feature is that the magnetic circuit system of the micro-speaker of the third embodiment is different from the magnetic circuit system of the first embodiment.
  • the magnetic circuit system of the microspeaker of the present embodiment mainly includes a yoke 1, a central magnet 2, a central topsheet 3, a side magnet 21, and a side topsheet 22.
  • the yoke 1 includes a rectangular yoke base plate 11 on which four side magnets 21 are provided.
  • the present embodiment is a five-magnetic circuit design comprising a central magnet 2 and four side magnets 21 attached to the central portion of the upper surface of the yoke base plate 11, and two side magnets 21 attached to the yoke base plate 11 At the edge of the upper surface, the central magnet 2 and the four side magnets 21 are made of the same magnetic medium, which together form a magnetic field in the magnetic circuit system.
  • the central magnet 2 is not in direct contact with the four side magnets 21, but remains separated, leaving sufficient clearance.
  • the center top sheet 3 is attached to the upper surface of the center magnet 2, and the center top sheet 3 corresponds to the shape and size of the center magnet 2.
  • the side top sheet 22 is an annular sheet which is attached to the upper surface of the four side magnets 21, and the side top sheet 22 corresponds to the shape and size of the four side magnets 21.
  • the yoke 1, the central magnet 2, the central topsheet 3, the side magnets 21 and the side topsheet 22 enclose an annular magnetic gap 7, also referred to as an annular magnetic gap or a magnetic gap.
  • the annular magnetic gap 7 is covered with a uniform magnetic field, and the magnetic induction intensity in the magnetic field is the same as the direction.
  • two or more low magnetic field nodes 8 are disposed in the annular magnetic gap 7, and a portion between any two low magnetic field nodes 8 in the annular magnetic gap 7 forms a magnetic gap region 9, at least one of the magnetic gap regions 9 Filled with magnetic fluid (not shown).
  • the low magnetic field node 8 can include a central topsheet notch 81 and/or a side topsheet notch 83.
  • Two or more central topsheet notches 81 are provided at the edge of the central topsheet 3, the opening direction of which faces the annular magnetic gap 7, preferably eight in the embodiment, and two central tops on the four sides of the central topsheet 3, respectively.
  • the central topsheet 3 is in close contact with the central magnet 2, and a portion of the central magnet 2 is exposed at the central topsheet notch 81.
  • the magnetic field density decreases, forming a low magnetic field strength region, which may be referred to as a "low magnetic field trap.”
  • Two or more apex notches 83 are provided at the edges of the side panels 22, and the opening direction thereof faces the annular magnetic gap 7, preferably eight in the present embodiment, corresponding to four central louver notches 81, respectively.
  • the side top sheet 22 is in close contact with the side magnet 21, and a part of the side magnet 21 is exposed at the top sheet notch 83.
  • the magnetic field density decreases, forming a region of low magnetic field strength, a "low magnetic field trap.”
  • the low magnetic field node may select only one of the central top sheet notch 81 or the side top sheet notch 83, or two types may be used at the same time. At this time, the position and the top of each central top sheet notch 81 are selected. The position of the sheet notch 83 corresponds.
  • the annular magnetic gap 7 is divided into eight magnetic gap portions by eight low magnetic field nodes 8, and a magnetic gap portion 9 between any two adjacent low magnetic field nodes 8 forms a small magnetic gap region 9.
  • the magnetic flux (not shown) may be filled in the four magnetic gap regions 9 located in the middle of the four sides of the rectangular annular magnetic gap 7, or the magnetic fluid may be filled in the two opposite magnetic gap regions 9. .
  • the magnetic fluid itself has magnetic properties. Since both ends of the small magnetic gap region are low magnetic field strength regions, when the magnetic fluid flows to a low magnetic field strength region, the magnetic fluid is subjected to a certain repulsive force, making it difficult for the magnetic fluid to pass through the low magnetic field strength region. It flows to other parts of the annular magnetic gap 7.
  • the magnetic fluid and the yoke 1, the central magnet 2, the central topsheet 3, the side magnets 21 and the side topsheet 22 together form a magnetic circuit system, which can further enhance the magnetic field strength in the four magnetic gap regions 9 and improve the sound quality of the speaker.
  • the five magnets and the magnetic flux region 9 filled with magnetic fluid in Embodiment 3 can provide higher magnetic field strength, better adjust the Q value of the speaker, and improve the transient response speed. Helps improve the frequency response of the speaker.
  • Other technical effects of the magnetic fluid in Embodiment 3 are the same as or similar to those of the magnetic fluids in Embodiments 1 and 2, and are not described herein.
  • Embodiment 3 also provides a method of manufacturing a magnetic circuit system as described above, comprising the following steps S1) to S3).
  • Step S1) enclosing the magnet, the yoke and the top sheet into a toroidal magnetic gap.
  • the step S1) includes: step S121) Attaching a central magnet to a central portion of the upper surface of the yoke bottom plate of the yoke; and step S122) attaching at least one set of opposite side magnets at an edge of the upper surface of the yoke bottom plate of the yoke; step S123) A central top sheet is attached to the upper surface of the central magnet, and a top sheet is attached to the upper surface of the side magnet.
  • step S2) arranging two or more low magnetic field nodes in the annular magnetic gap such that a portion between any two low magnetic field nodes in the annular magnetic gap forms a magnetic gap region.
  • two or more central topsheet notches are provided at the edge of the central topsheet, the opening direction of which faces the annular magnetic gap; and/or two or more topsheets are provided at the edge of the sidesheet The notch has an opening direction facing the annular magnetic gap.
  • step S2) before setting the low magnetic field node, it is necessary to calculate the amount of magnetic fluid and calculate the position of the low magnetic field node; it is also necessary to calculate the size of the central top sheet notch and/or the side top sheet notch.
  • step S1) to step S3) components such as the voice coil 4, the diaphragm 5, the basin frame 6, and the magnetic circuit system are assembled, and a microspeaker can be produced.
  • the position of the low magnetic field node can be set as needed, and the amount of magnetic fluid in the magnetic circuit system can be adjusted by itself, thereby effectively adjusting the damping of the voice coil and the diaphragm.
  • the advantage of this embodiment is that, relative to Embodiments 1, 2, the five magnets and the four magnetic fluid filled magnetic gap regions of the present embodiment can provide higher magnetic field strength, better adjust the Q value of the speaker, and improve Transient response speed helps improve the frequency response of the speaker.
  • this embodiment can reduce the occurrence of the voice coil friction yoke phenomenon, thereby reducing the distortion of the speaker, especially the harmonic distortion, and effectively improving the sound quality of the speaker.
  • the heat dissipation effect of the voice coil can be effectively improved, and the heat loss of the speaker caused by the overheating of the voice coil can be avoided.
  • the micro-speaker of this embodiment can withstand greater input power, and can make the input power of the micro-speaker more than twice the original input power.

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Abstract

一种磁路系统，包括环形磁间隙（7）、两个以上低磁场节点（8）、磁隙区（9）以及磁流体（10）；所述环形磁间隙（7）由磁轭（1）、磁铁（2）、顶片（3）围成；所述低磁场节点（8）设于所述环形磁间隙（7）内；所述磁隙区（9）为所述环形磁间隙（7）内任意两个低磁场节点（8）之间的部分；所述磁流体（10）被填充于至少一个磁隙区（9）内。还提供一种所述磁路系统的制造方法，以及一种微型扬声器，所述微型扬声器包括所述磁路系统。

Description

一种磁路系统及其制造方法、微型扬声器
技术领域
本发明涉及扬声器技术领域，具体涉及一种磁路系统及其制造方法、微型扬声器。
背景技术
扬声器的结构，一般包括磁路系统、振动系统及固定系统三个部分；其磁路系统主要包括磁体、磁轭及华司（顶片），三者围成环形磁间隙，其间布满均匀磁场；其振动系统主要包括设于环形磁间隙内的音圈及与音圈一体设置的振膜；其固定系统包括盆架等，用于固定安装所述磁路系统及所述振动系统。在扬声器中，音圈获取一电信号后，在磁场内切割磁力线，在环形磁间隙内轴向振荡，从而带动振膜发生振荡，从而发出相应的声音。
在扬声器设计领域，如何调整和平衡音圈及振膜阻尼一直是研发人员的重要课题，如果阻尼过大，音圈振动困难，就会导致扬声器声压损失过大、发声音质较差；如果阻尼过小，扬声器的Q值就会过高，扬声器瞬态的后沿特性就会比较差，发声浑浊。因此，人们需要多种可以增大或减小振膜阻尼的技术手段，以实现对振膜阻尼的精确控制，进一步提升扬声器的发声音质。
现有技术的微型扬声器，例如手机中的听筒、耳机等，为了增加振膜的阻尼，经常采用如下三种技术手段。第一种是采用多层复合振膜，以提高阻尼，其不足之处在于，这种方式能提供的阻尼比较小，作用比较有限，难以达到最佳效果；第二种是在振膜上加阻尼胶，其不足之处在于，阻尼胶有一定流动性，长时间或高温条件下会流失；第三种是加装低透气度的阻尼网，其不足之处在于，由于网布型号有限，只能大致调整振膜的振幅，难以做到精确调整，而且阻尼网的贴合需要专门工艺，生产成本较高。
现有技术的微型扬声器，由于体积较小，其内部的音圈容易与磁路系统发生碰撞，其振膜容易发生滚振现象，从而导致扬声器产生较大杂音。
随着智能功放（Smart PA）在移动终端领域大规模普及，对高功率微型扬声器的需求越来越大。现有技术的微型扬声器，音圈周围只有空气作为散热介质，其散热能力较差，只能承受较小的工作电流；当工作电流较大时，音圈就会因过热导致被烧毁，无法承受高功率的工作电流。
现有技术的微型扬声器，其磁路系统提供的磁场强度比较小，其工作电流也比较小，音圈容易碰撞磁路系统，振膜容易发生滚振，因此其音质、音量都比较差。为了提升微型扬声器音质，只能改进磁路系统及振动系统的部件材质和加工精度，这样就大幅提高了生产成本，导致高音质微型扬声器价格昂贵，不利于市场推广。
磁流体，又称磁性液体、铁磁流体或磁液，是由直径为纳米量级(9纳米以下）的磁性固体颗粒、基载液以及界面活性剂三者混合而成的一种稳定的胶状液体。磁流体在静态时无磁性吸引力，当外加磁场作用时，才表现出磁性，在磁场的作用下可以自动定位，而不会四处流动。目前，磁流体技术已经应用于大尺寸扬声器领域，将磁流体设置于扬声器音圈和磁隙的间隙中，可以有效改善扬声器的性能。
然而，磁流体技术在微型扬声器领域却少有应用，其原因在于，微型扬声器的功率很小、输入电流也小，驱动音圈发生振动的驱动力很弱。一旦在微型扬声器的磁间隙中加入磁流体，受其粘滞性的影响，会使得音圈振动困难、振膜阻尼过大，从而影响振膜的振动发声，使得微型扬声器声压损失过大、发声音质较差。
因此，本领域的技术人员致力于开发一种可以将磁流体技术应用到微型扬声器的技术方案，将磁路系统中的环形磁间隙分成若干个磁隙区，只在其中的一个部分或几个部分添加磁流体，使得只有音圈的一部分会受到磁流体粘滞力影响，从而适当增加音圈阻尼，而不会导致音圈阻尼过大。
发明内容
有鉴于现有技术的上述缺陷，本发明的目的在于，提供一种磁路系统，以解决现有技术中存在的无法将磁流体技术应用于微型扬声器的技术问题。
为解决上述技术问题，本发明提供一种磁路系统，包括环形磁间隙、两个以上低磁场节点、磁隙区以及磁流体；所述环形磁间隙由磁轭、磁铁、顶片围成；所述低磁场节点设于所述环形磁间隙内；所述磁隙区为所述环形磁间隙内任意两个低磁场节点之间的部分；所述磁流体被填充于至少一个磁隙区内。
进一步地，在不同实施方式中，所述磁轭包括磁轭底板及磁轭侧板；所述磁轭侧板设于所述磁轭底板边缘处。
进一步地，在不同实施方式中，所述磁铁包括中央磁铁和/或边磁铁，所述中央磁铁贴附于所述磁轭底板上表面的中部；所述边磁铁贴附于所述磁轭底板上表面的边缘处。
进一步地，在不同实施方式中，所述顶片包括中央顶片和/或边顶片，所述中央顶片贴附于所述中央磁铁上表面；所述边顶片贴附于所述边磁铁上表面。
进一步地，在不同实施方式中，所述低磁场节点包括两个以上中央顶片缺口和/或两个以上边顶片缺口和/或两个以上磁轭凹槽，所述中央顶片缺口设于所述中央顶片边缘处，其开口方向朝向所述环形磁间隙；所述边顶片缺口设于所述边顶片边缘处，其开口方向朝向所述环形磁间隙；所述磁轭凹槽设于所述磁轭侧板上端。
进一步地，在不同实施方式中，当所述低磁场节点包括中央顶片缺口，还包括边顶片缺口和/或磁轭凹槽时，每一中央顶片缺口的位置与一个边顶片缺口和/或一个磁轭凹槽的位置彼此对应。
进一步地，在不同实施方式中，所述磁轭包括磁轭底板。
进一步地，在不同实施方式中，所述磁铁包括中央磁铁以及边磁铁，所述中央磁铁贴附于所述磁轭底板上表面的中部；所述边磁铁贴附于所述磁轭底板上表面的边缘处。
进一步地，在不同实施方式中，所述顶片包括中央顶片以及边顶片，所述中央顶片贴附于所述中央磁铁上表面； 所述边顶片贴附于所述边磁铁上表面。
进一步地，在不同实施方式中，所述低磁场节点包括两个以上中央顶片缺口和/或两个以上边顶片缺口，所述中央顶片缺口设于所述中央顶片边缘处，其开口方向朝向所述环形磁间隙；所述边顶片缺口设于所述边顶片边缘处，其开口方向朝向所述环形磁间隙。
进一步地，在不同实施方式中，当所述低磁场节点包括中央顶片缺口和边顶片缺口时，每一中央顶片缺口的位置与一个边顶片缺口的位置彼此对应。
进一步地，在不同实施方式中，填充有所述磁流体的磁隙区为轴对称图形，其对称轴为所述环形磁间隙的一中心线。
本发明的目的在于，提供一种微型扬声器，以解决现有技术中存在的无法将磁流体技术应用于微型扬声器的技术问题。
为解决上述技术问题，本发明还提供一种微型扬声器，包括前文所述的任一种磁路系统。
进一步地，在不同实施方式中，所述微型扬声器还包括音圈，设于所述环形磁间隙内；所述磁流体填充于所述音圈两侧和/或其底部；所述磁流体粘附于所述磁轭和/或所述磁铁和/或所述顶片的边缘处。
进一步地，在不同实施方式中，所述微型扬声器包括但不限于平板形振膜扬声器、圆锥形振膜扬声器或球顶形扬声器。
本发明的目的在于，提供一种磁路系统的制造方法，以解决现有技术中存在的无法将磁流体技术应用于微型扬声器的技术问题。
为解决上述技术问题，本发明还提供一种所述磁路系统的制造方法，包括如下步骤：将磁铁、磁轭与顶片围成环形磁间隙；在所述环形磁间隙内设置两个以上低磁场节点，所述环形磁间隙内任意两个低磁场节点之间的部分形成一个磁隙区；向至少一个磁隙区内填充磁流体。
进一步地，在不同实施方式中，将磁轭、磁铁与顶片围成环形磁间隙的步骤，包括如下步骤：在所述磁轭的磁轭底板上表面的边缘处设置磁轭侧板；在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；在所述中央磁铁上表面贴附中央顶片。
进一步地，在不同实施方式中，在所述环形磁间隙内设置两个以上低磁场节点的步骤，包括如下步骤：在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或在所述磁轭侧板上端设置两个以上磁轭凹槽。
进一步地，在不同实施方式中，将磁铁、磁轭与顶片围成环形磁间隙的步骤中，还包括如下步骤：在所述磁轭的磁轭底板上表面的边缘处贴附至少一组彼此相对的边磁铁；在所述边磁铁上表面贴附边顶片。
进一步地，在不同实施方式中，在所述环形磁间隙内设置两个以上低磁场节点的步骤，包括如下步骤：在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或在所述边顶片边缘处设置两个以上边顶片缺口，其开口方向朝向所述环形磁间隙；和/或在所述磁轭侧板上端设置两个以上磁轭凹槽。
进一步地，在不同实施方式中，将磁铁、磁轭与顶片围成环形磁间隙的步骤，包括如下步骤：在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；在所述磁轭的磁轭底板上表面的边缘处贴附至少一组彼此相对的边磁铁；在所述中央磁铁上表面贴附中央顶片，且在所述边磁铁上表面贴附边顶片。
进一步地，在不同实施方式中，在所述环形磁间隙内设置两个以上低磁场节点的步骤，包括如下步骤：在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或在所述边顶片边缘处设置两个以上边顶片缺口，其开口方向朝向所述环形磁间隙。
本发明的优点在于，本发明提供一种磁路系统及其制造方法，还提供一种微型扬声器，可以将磁流体技术应用到微型扬声器中，将磁路系统中的环形磁间隙分成若干个彼此分离的部分，只在其中的一个或几个部分添加磁流体，而不是将整个环形磁间隙充满磁流体，这样只有音圈的一部分会受到磁流体粘滞力影响，从而适当增加音圈阻尼，而不会导致音圈阻尼过大，使得磁流体技术也可以应用在微型扬声器中，提高磁场强度，改善音圈的散热条件、减少音圈摩擦磁轭现象，从而可以有效改善扬声器的性能。更重要的是，磁隙区的长度、磁流体填充量可以由设计人员根据需要自动调整，从而实现音圈阻尼/振膜阻尼的精确控制。
以下将结合附图对本发明的构思、具体结构及产生的技术效果作进一步说明，以充分地了解本发明的目的、特征和效果。
附图说明
图1为本发明实施例1中一种微型扬声器的分解结构示意图；
图2为本发明实施例1中一种磁路系统的整体结构示意图；
图3为本发明实施例1中一种磁路系统的俯视结构图；
图4为本发明实施例1中一种磁路系统中加入音圈和磁流体的俯视结构图；
图5为本发明改进型实施例1中一种微型扬声器的分解结构示意图；
图6为本发明改进型实施例1中一种磁路系统的整体结构示意图；
图7为本发明实施例1-3中一种磁路系统的制造方法的流程图；
图8为本发明实施例1中一种围成环形磁间隙的方法流程图；
图9为本发明实施例2中一种磁路系统的整体结构示意图；
图10为本发明实施例2中一种磁路系统的分解结构示意图；
图11为本发明实施例2中一种围成环形磁间隙的方法流程图；
图12为本发明实施例3中一种磁路系统的整体结构示意图；
图13为本发明实施例3中一种磁路系统的分解结构示意图；
图14为本发明实施例3中一种围成环形磁间隙的方法流程图。
图中部件标识如下：
1磁轭，2中央磁铁，3中央顶片，4音圈，5振膜，6盆架；
7环形磁间隙， 8低磁场节点，9磁隙区，10磁流体；
11磁轭底板，12磁轭侧板；
21边磁铁，22边顶片；
81中央顶片缺口，82磁轭凹槽；
91第一磁隙区，92第二磁隙区，93第三磁隙区，94第四磁隙区；
901第一对称轴，902第二对称轴。
具体实施方式
以下参考说明书附图介绍本发明的优选实施例，可以向本领域中的技术人员完整介绍本发明，使其技术内容更加清楚和便于理解。本发明可以通过许多不同形式的实施例来得以体现，本发明的保护范围并非仅限于文中提到的实施例。
在附图中，结构相同的部件以相同数字标号表示，各处结构或功能相似的部件以相似数字标号表示。附图所示的每一部件的尺寸和厚度是任意示出的，本发明并没有限定每个部件的尺寸和厚度。为了使图示更清晰，附图中有些地方适当夸大了部件的厚度。
本发明所提到的方向用语，例如，上、下、前、后、左、右、内、外、侧面、顶部、底部、顶端、底端、末端等，仅是附图中的方向，只是用来解释和说明本发明，而不是用来限定本发明的保护范围。
当某些部件被描述为“在”另一部件“上”时，所述部件可以直接置于所述另一部件上；也可以存在一中间部件，所述部件置于所述中间部件上，且所述中间部件置于另一部件上。当一个部件被描述为“安装至”或“连接至”另一部件时，二者可以理解为直接“安装” 或“连接”，或者一个部件通过一中间部件间接 “安装至”或“连接至”另一个部件。
实施例1
实施例1以一种单磁路平板形振膜扬声器为例，详细介绍本发明的结构。本实施例所述微型扬声器也可以为其他类型扬声器，还包括圆锥形振膜扬声器或球顶形扬声器，等等。
如图1所示，实施例1所述微型扬声器包括磁轭1、中央磁铁2、中央顶片3、音圈4、振膜5及盆架6。
如图2所示，本实施例所述微型扬声器的磁路系统，主要包括磁轭1、中央磁铁2及中央顶片3。
如图1~2所示，实施例1中，磁轭1包括磁轭底板11及磁轭侧板12，磁轭侧板12设于磁轭底板11边缘处；磁轭侧板12及磁轭底板11围成磁轭盆腔13。磁轭1 本身不产生磁场（磁力线），在磁路系统中只起磁力线传输作用，一般采用软磁材料，例如导磁率比较高的软铁或软磁合金等。
磁轭侧板12均匀对称地分布于音圈4的四周，约束音圈4漏磁向外扩散，提高感应介入的效率。本实施例中，磁轭底板11为矩形，磁轭侧板12为四块首尾相连的矩形板，分别设于磁轭底板11四条边上，在相邻两块矩形板的连接处可能设有小的侧板缺口。磁轭1也可以为其他形状，例如圆形，此时磁轭底板11为圆形，磁轭侧板12为无缺口的圆环。
中央磁铁2设于磁轭盆腔13内，且贴附于磁轭底板11上表面的中部，但中央磁铁2与磁轭侧板12不直接接触，而是保持分离状态，为二者保留足够的间隙。中央顶片3贴附于中央磁铁2上表面，中央顶片3与中央磁铁2的形状、尺寸相对应。
如图3所示，中央顶片3、中央磁铁2及磁轭1围成环形磁间隙7，也称为环形磁隙或磁隙。环形磁间隙7内布满均匀磁场，该磁场内磁感应强度大小与方向处处相同。
音圈4设于环形磁间隙7内，音圈4获取电信号后，在磁场内切割磁力线，在环形磁间隙7内上下振动（振荡）。
如图1所示，振膜5设于音圈4及中央顶片3上方，并连接至音圈4。本实施例中的振膜5为下沉式振膜，音圈4收到不同频率的电信号，会以不同频率发生物理振动，振膜5周围的空气介质与振膜5共同作用，从而发出频率不同的声音，扬声器发声的整个过程就是电、力、声的转换过程。
实施例1所述微型扬声器还包括盆架6，磁轭1固定安装至盆架6内，振膜5固定连接至盆架6顶部，从而使得扬声器的各个部件形成一个整体。
在实施例1中，环形磁间隙7内设有两个以上低磁场节点8，优选四个或八个，环形磁间隙7内任意两个低磁场节点8之间的部分形成磁隙区9，至少一个磁隙区9内填充有磁流体10。
如图3~4所示，在实施例1中可以包括四个低磁场节点8，每一低磁场节点8可以包括中央顶片缺口81和/或磁轭凹槽82。
在中央顶片3边缘处设有两个以上中央顶片缺口81，优选四个，其开口方向朝向环形磁间隙7，中央顶片3与中央磁铁2紧贴，中央顶片缺口81处露出中央磁铁2的一部分。在环形磁间隙7内正对中央顶片缺口81的部分，磁力线密度会降低，形成低磁场强度区域，可以将其称为“低磁场陷阱”。
磁轭侧板12上端设有两个以上磁轭凹槽82，优选四个。在环形磁间隙7内正对磁轭凹槽82的部分，磁力线密度会降低，会形成低磁场强度区域。
实施例1中，可以只选用中央顶片缺口81或磁轭凹槽82作为低磁场节点，也可以同时使用中央顶片缺口81和磁轭凹槽82作为低磁场节点，此时每一中央顶片缺口81的位置与一磁轭凹槽82的位置相对应。
如图3所示，环形磁间隙7被两个以上低磁场节点8分隔成多个磁间隙部分，任意两个相邻低磁场节点8之间的磁间隙部分形成一个小型的磁隙区9。本实施例中四个低磁场节点8将环形磁间隙7分成四个磁隙区9，包括第一磁隙区91、第二磁隙区92、第三磁隙区93及第四磁隙区94，彼此相对的第一磁隙区91与第三磁隙区93的长度相等；彼此相对的第二磁隙区92与第四磁隙区94的长度相等。填充磁流体10的磁隙区的长短会影响扬声器音圈的阻尼，磁隙区越长，磁流体填充越多，音圈的阻尼也就越大；反之，磁隙区越短，磁流体填充越少，音圈的阻尼也就越小。因此，设计人员可以通过调整磁隙区长度的手段来调节音圈阻尼。
在一个或多个小型磁隙区内填充有磁流体10，如图4所示，优选地，在第一磁隙区91与第三磁隙区93填充磁流体。磁流体10本身具有磁性，由于小型磁隙区两端皆为低磁场强度区域，磁流体10流动到一个低磁场强度区域时，磁流体10会受到一定斥力，使得难以磁流体10穿过该低磁场强度区域，流向环形磁间隙7的其他部分。磁流体10与磁轭1、中央磁铁2、中央顶片3共同组成磁路系统，可以进一步提升第一磁隙区91、第三磁隙区93内的磁场强度，提升扬声器的音质。
本实施例1中，中央顶片缺口81的横截面为半圆形或弓形，便于进行磁场强度的计算和磁力线的描画。中央顶片缺口81的横截面直径为中央顶片3厚度的30%~200%，其横截面直径由设计者根据需要自行计算和调整，计算过程中需要参考各种参数，如中央磁铁的磁介质参数、磁流体的磁介质参数、音圈质量等。中央顶片缺口81横截面的面积越大，中央顶片3下露出的中央磁铁2面积越大，该中央顶片缺口81处的磁力线分布也就越分散，磁流体10会受到的斥力也就越大，磁流体10越难穿过低磁场强度区域流入环形磁间隙7中的其他区域。同时，很多磁流体10材料在高温、高磁环境下，可以降低流动性，成为半凝固状态的胶状物。
由于音圈4设于环形磁间隙7内，磁流体10填充于环形磁间隙7内的一个或几个小型磁隙区内，具体地说，磁流体10是填充于磁轭1、中央磁铁2、中央顶片3及音圈4之间的间隙内，因此，磁流体10填充于音圈4两侧和/或其底部，且贴附于磁轭1和/或中央顶片3边缘处。
本实施例中音圈4两侧都填充有磁流体10，如果只设置中央顶片缺口81作为低磁场节点8，靠近中央顶片3一侧的的磁流体10受到斥力较大，另一侧的磁流体10受到斥力较小，就有可能造成磁流体10的泄露。同理，如果只设置磁轭凹槽82作为低磁场节点8，靠近磁轭侧板12一侧的磁流体10受到斥力较大，另一侧的磁流体10受到斥力较小，也有可能造成磁流体10的泄露。为了使得音圈4两侧磁流体10受到斥力大小相同或近似，因此优选同时使用中央顶片缺口81和磁轭凹槽82作为低磁场节点的方案。
磁流体10粘附于音圈4上，由于磁流体10自身具备粘滞力，因此可以在一定程度上增大音圈4及振膜5的阻尼。一个小型磁隙区内磁流体10形成的阻尼，是由环形磁间隙7内磁流体10用量来决定的，也可以说，是由两个中央顶片缺口81之间的距离来决定的，两个相邻低磁场节点的间距与磁流体用量成正比。一般情况下，任意两个中央顶片缺口81之间的距离为中央顶片3长度的30%~80%，该距离的具体数值可以由设计者根据需要自行计算和调整，计算过程中需要参考各种参数，如不同类型磁流体10的磁介质参数、音圈质量参数、环形磁间隙宽度等。
填充有磁流体10的任意一个磁隙区皆为轴对称图形，其对称轴为环形磁间隙9的一条中心线。填充有磁流体10的磁隙区一般都是成对出现的，一组相对的磁隙区关于环形磁间隙9的一条中心线对称，从而保证音圈两侧或多侧受力平衡。如果只有一个填充磁流体10的磁隙区，必然会导致音圈单侧受力偏大，从而使得音圈无法正常振动。
本实施例中，如图3所示，第一磁隙区91和第三磁隙区93内填充有磁流体10，第一磁隙区91、第三磁隙区93皆为轴对称图形，其对称轴皆为环形磁间隙9的一条中心线，可以称其为第一对称轴901，第一磁隙区91、第三磁隙区93两端的低磁场节点8到第一对称轴901的距离相等。同时，第一磁隙区91、第三磁隙区93关于环形磁间隙9的另一条中心线对称，可以称该中心线为第二对称轴902。音圈4在相对的两个方向受到同样大小的磁流体10粘滞力的影响，这样才能实现音圈4的阻尼平衡，使得音圈4在通电后可以平稳地发生振动，不会发生倾斜。
类似地，如图5~6所示，实施例1的技术方案可以进一步改进，改进型实施例1可以包括八个低磁场节点8，每一低磁场节点8可以包括中央顶片缺口81和/或磁轭凹槽82，其工作原理及技术效果与四个低磁场节点的情况类似，在此不做赘述。
现有技术的微型扬声器，其磁场强度普遍比较弱，为了提高磁场强度，只能采用减少中央顶片3与磁轭1的距离的方式。其不足之处在于，这种方式对组装加工工艺要求很高，大幅提高了加工成本。在本实施例中，当阻尼调整到合适的数值时，磁路系统（包括磁轭1、中央磁铁2、中央顶片3及磁流体10）可以提供更高的磁场强度，可以更好地调整扬声器的Q值，提高瞬态响应速度，有利于改善扬声器的频率响应。
现有技术的微型扬声器，其振膜非常薄，轻微的不平衡就会引发滚振，使得音圈4碰撞磁路系统的部件（如磁轭1、中央磁铁2或中央顶片3），从而产生杂音。在本实施例中，由于磁流体10填充于音圈4两侧和/或其底部，可以使音圈悬浮，实现自动定位。磁流体10将音圈4与磁轭1隔离开，因此在音圈4发生振荡时，可以减少音圈摩擦磁轭现象的发生，进而可以减少扬声器的失真，特别是高次谐波失真。
现有技术的微型扬声器，对输入功率的需求越来越高，这样在扬声器工作中产生的热量也会越来越大。由于微型扬声器体积较小，而且空气介质的导热能力差，因此音圈的散热能力较差，很容易会由于音圈高温而导致扬声器的热损毁。在本实施例中，由于磁流体导热系数是空气介质的6倍以上，可以有效改善音圈的散热效果，可以避免因音圈过热而导致的扬声器热损毁。本实施例的微型扬声器，可以承受更大的输入功率，可以使得微型扬声器可承受的输入功率达到原来的2倍以上。
如图7所示，实施例1还提供一种如前文所述磁路系统的制造方法，包括下述步骤S1）~步骤S3）。
步骤S1）将磁铁、磁轭与顶片围成环形磁间隙。如图8所示，步骤S1）具体包括：步骤S101） 在所述磁轭的磁轭底板上表面的边缘处设置磁轭侧板；步骤S102）在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；步骤S103）在所述中央磁铁上表面贴附中央顶片。
步骤S2）在所述环形磁间隙内设置两个以上低磁场节点，使得所述环形磁间隙内任意两个低磁场节点之间的部分形成一个磁隙区。具体地说，在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或在所述磁轭侧板上端设置两个以上磁轭凹槽。步骤S2）中，在设置低磁场节点之前，需要计算磁流体用量、计算低磁场节点的位置；还需要计算所述中央顶片缺口和/或所述磁轭凹槽的尺寸，两个相邻低磁场节点之间的间距与磁流体用量成正比。
步骤S3）向至少一个磁隙区内填充磁流体，从而将磁路系统组装完成。
步骤S1）~步骤S3）之后，将音圈4、振膜5、盆架6等部件及磁路系统组装在一起，即可以生产出微型扬声器。
实施例1所述磁路系统的制造方法，可以根据需要设置低磁场节点的位置，自行调整磁路系统中的磁流体用量，从而有效调整音圈和振膜的阻尼。
本实施例优点在于，本实施例可以适当调整音圈和振膜的阻尼，其磁路系统可以提供更高的磁场强度，更好地调整扬声器的Q值，提高瞬态响应速度，有利于改善扬声器的频率响应。在音圈发生振荡时，本实施例可以减少音圈摩擦磁轭现象的发生，进而可以减少扬声器的失真，特别是高次谐波失真，可以有效改善扬声器的音质。本实施例可以有效改善音圈的散热效果，可以避免因音圈过热而导致的扬声器热损毁。本实施例的微型扬声器，可以承受更大的输入功率，可以使得微型扬声器可承受的输入功率达到原来的2倍以上。
实施例2
实施例2提供另一种微型扬声器，其技术方案大部分与实施例1相同，其区别特征在于，实施例2所述微型扬声器的磁路系统与实施例1的磁路系统不同。
如图9~10所示，本实施例所述微型扬声器的磁路系统，主要包括磁轭1、中央磁铁2、中央顶片3、边磁铁21及边顶片22。
实施例2中，磁轭1包括一个矩形磁轭底板11，矩形磁轭底板11上一组相对边上设有两个相对设置的磁轭侧板12，其另一组相对边上设有两个边磁铁21。
两个磁轭侧板12设于磁轭底板11边缘处，两个相对设置的磁轭侧板12本身不产生磁场，在磁路系统中只起磁力线传输作用，一般采用软磁材料、例如导磁率比较高的软铁或软磁合金等。
本实施例为三磁路设计，包括一个中央磁铁2和两个边磁铁21，中央磁铁2贴附于磁轭底板11上表面的中部，两个边磁铁21贴附于所述磁轭底板11上表面的边缘处，中央磁铁2与两个边磁铁21为同样的磁介质制成，共同形成磁路系统中的磁场。
中央磁铁2与两个边磁铁21、磁轭侧板12不直接接触，而是保持分离状态，保留足够的间隙。中央顶片3贴附于中央磁铁2上表面，中央顶片3与中央磁铁2的形状、尺寸相对应。四个边顶片22贴附于四个边磁铁21上表面，每一边顶片22与其下方边磁铁21的形状、尺寸相对应。
磁轭1、中央磁铁2、中央顶片3、边磁铁21及边顶片22围成环形磁间隙7，也称为环形磁隙或磁隙。环形磁间隙7内布满均匀磁场，该磁场内磁感应强度大小与方向处处相同。
在实施例2中，环形磁间隙7内设有两个以上低磁场节点8，环形磁间隙7内任意两个低磁场节点8之间的部分形成磁隙区9，至少一个磁隙区9内填充有磁流体10。低磁场节点8可以包括中央顶片缺口81和/或磁轭凹槽82和/或边顶片缺口83。
在中央顶片3边缘处设有两个以上中央顶片缺口81，其开口方向朝向环形磁间隙7，本实施例中优选八个，中央顶片3的四条边上分别设有两个中央顶片缺口81。中央顶片3与中央磁铁2紧贴，中央顶片缺口81处露出中央磁铁2的一部分。在环形磁间隙7内正对中央顶片缺口81的部分，磁力线密度会降低，形成低磁场强度区域，可以将其称为“低磁场陷阱”。
磁轭侧板12上端设有两个以上磁轭凹槽82，本实施例中优选四个，分别对应四个中央顶片缺口81。在环形磁间隙7内正对磁轭凹槽82的部分，磁力线密度会降低，会形成低磁场强度区域，即“低磁场陷阱”。
在边顶片22边缘处设有两个以上边顶片缺口83，其开口方向朝向环形磁间隙7，本实施例中优选四个，分别对应四个中央顶片缺口81。边顶片22与边磁铁21紧贴，边顶片缺口83处露出边磁铁21的一部分。在环形磁间隙7内正对边顶片缺口83的部分，磁力线密度会降低，形成低磁场强度区域，即“低磁场陷阱”。
实施例2中，低磁场节点可以只选用中央顶片缺口81或磁轭凹槽82或边顶片缺口83中的任一种，也可以同时使用其中的两种或三种，此时，每一中央顶片缺口81的位置与一磁轭凹槽82和/或边顶片缺口83的位置相对应。
利用本实施例所述磁路系统制造一种微型扬声器，将音圈设于环形磁间隙7内，磁流体（图未示）填充于音圈两侧和/或其底部。如果只选用中央顶片缺口81或磁轭凹槽82或边顶片缺口83中的一种，音圈两侧磁流体受到斥力有大小区别，有可能造成磁流体的泄露。为了使得音圈两侧磁流体受到斥力大小相同或近似，优选同时使用中央顶片缺口81和磁轭凹槽82和/或边顶片缺口83作为低磁场节点的方案。
本实施例中，环形磁间隙7被八个低磁场节点8分隔成八个磁间隙部分，任意两个相邻低磁场节点8之间的磁间隙部分形成一个小型的磁隙区9。本实施例中，位于矩形环形磁间隙7四条边的中部的四个磁隙区9内皆可以填充磁流体，或者，可以在两个相对的磁隙区9内填充磁流体。
磁流体本身具有磁性，由于小型磁隙区两端皆为低磁场强度区域，磁流体流动到一个低磁场强度区域时，磁流体会受到一定斥力，使得磁流体难以穿过该低磁场强度区域，流向环形磁间隙7的其他部分。磁流体与磁轭1、中央磁铁2、中央顶片3、边磁铁21及边顶片22共同组成磁路系统，可以进一步提升上述四个磁隙区9内的磁场强度，提升扬声器的音质。
相对于实施例1，实施例2中的三个磁铁和四个填充磁流体的磁隙区可以提供更高的磁场强度，更好地调整扬声器的Q值，提高瞬态响应速度，有利于改善扬声器的频率响应。实施例2中磁流体的其他技术效果与实施例1中磁流体的技术效果相同或类似，在此不做赘述。
实施例2还提供一种如前文所述磁路系统的制造方法，如图7所示，包括下述步骤S1）~步骤S3）。
步骤S1）将磁铁、磁轭与顶片围成环形磁间隙。如图11所示，步骤S1）具体包括如下步骤：步骤S111）在所述磁轭的磁轭底板上表面的边缘处设置至少一组彼此相对的磁轭侧板，相邻的两个磁轭侧板之间形成侧板缺口；步骤S112）在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；步骤S113）在所述磁轭的磁轭底板上表面的边缘处贴附至少一组彼此相对的边磁铁，所述边磁铁设于所述侧板缺口处；步骤S114）在所述中央磁铁上表面贴附中央顶片，且在所述边磁铁上表面贴附边顶片。
步骤S2）在所述环形磁间隙内设置两个以上低磁场节点，使得所述环形磁间隙内任意两个低磁场节点之间的部分形成一个磁隙区。具体地说，在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或，在所述边顶片边缘处设置两个以上边顶片缺口，其开口方向朝向所述环形磁间隙；和/或，在所述磁轭侧板上端设置两个以上磁轭凹槽。步骤S2）中，在设置低磁场节点之前，需要计算磁流体用量、计算低磁场节点的位置；还需要计算所述中央顶片缺口和/或所述边顶片缺口和/或所述磁轭凹槽的尺寸。
步骤S3）向至少一个磁隙区内填充磁流体，从而将磁路系统组装完成。
步骤S1）~步骤S3）之后，将音圈4、振膜5、盆架6等部件及本实施例所述磁路系统组装在一起，即可以生产出微型扬声器。
实施例2所述磁路系统的制造方法，可以根据需要设置低磁场节点的位置，自行调整磁路系统中的磁流体用量，从而有效调整音圈和振膜的阻尼。
本实施例优点在于，相对于实施例1，本实施例中的三个磁铁和四个填充磁流体的磁隙区可以提供更高的磁场强度，更好地调整扬声器的Q值，提高瞬态响应速度，有利于改善扬声器的频率响应。在音圈发生振荡时，本实施例可以减少音圈摩擦磁轭现象的发生，进而可以减少扬声器的失真，特别是高次谐波失真，可以有效改善扬声器的音质。本实施例可以有效改善音圈的散热效果，可以避免因音圈过热而导致的扬声器热损毁。本实施例的微型扬声器，可以承受更大的输入功率，可以使得微型扬声器可承受的输入功率达到原来的2倍以上。
实施例3
实施例3提供另一种微型扬声器，其技术方案大部分与实施例1相同，其区别特征在于，实施例3所述微型扬声器的磁路系统与实施例1的磁路系统不同。
如图12~13所示，本实施例所述微型扬声器的磁路系统，主要包括磁轭1、中央磁铁2、中央顶片3、边磁铁21及边顶片22。磁轭1包括一个矩形磁轭底板11，其四条边上设有四个边磁铁21。
本实施例为五磁路设计，包括一个中央磁铁2和四个边磁铁21，中央磁铁2贴附于磁轭底板11上表面的中部，两个边磁铁21贴附于所述磁轭底板11上表面的边缘处，中央磁铁2与四个边磁铁21为同样的磁介质制成，共同形成磁路系统中的磁场。
中央磁铁2与四个边磁铁21不直接接触，而是保持分离状态，保留足够的间隙。中央顶片3贴附于中央磁铁2上表面，中央顶片3与中央磁铁2的形状、尺寸相对应。边顶片22为一个环形片，同时贴附于四个边磁铁21上表面，边顶片22与四个边磁铁21的形状、尺寸相对应。
磁轭1、中央磁铁2、中央顶片3、边磁铁21及边顶片22围成环形磁间隙7，也称为环形磁隙或磁隙。环形磁间隙7内布满均匀磁场，该磁场内磁感应强度大小与方向处处相同。
在实施例3中，环形磁间隙7内设有两个以上低磁场节点8，环形磁间隙7内任意两个低磁场节点8之间的部分形成磁隙区9，至少一个磁隙区9内填充有磁流体（图未示）。低磁场节点8可以包括中央顶片缺口81和/或边顶片缺口83。
在中央顶片3边缘处设有两个以上中央顶片缺口81，其开口方向朝向环形磁间隙7，本实施例中优选八个，中央顶片3的四条边上分别设有两个中央顶片缺口81。中央顶片3与中央磁铁2紧贴，中央顶片缺口81处露出中央磁铁2的一部分。在环形磁间隙7内正对中央顶片缺口81的部分，磁力线密度会降低，形成低磁场强度区域，可以将其称为“低磁场陷阱”。
在边顶片22边缘处设有两个以上边顶片缺口83，其开口方向朝向环形磁间隙7，本实施例中优选八个，分别对应四个中央顶片缺口81。边顶片22与边磁铁21紧贴，边顶片缺口83处露出边磁铁21的一部分。在环形磁间隙7内正对边顶片缺口83的部分，磁力线密度会降低，形成低磁场强度区域，即“低磁场陷阱”。
实施例3中，低磁场节点可以只选用中央顶片缺口81或边顶片缺口83中的任一种，也可以同时使用两种，此时，每一中央顶片缺口81的位置与一边顶片缺口83的位置相对应。
本实施例中，环形磁间隙7被八个低磁场节点8分隔成八个磁间隙部分，任意两个相邻低磁场节点8之间的磁间隙部分形成一个小型的磁隙区9。本实施例中，位于矩形环形磁间隙7四条边的中部的四个磁隙区9内皆可以填充磁流体（图未示），或者，可以在两个相对的磁隙区9内填充磁流体。
磁流体本身具有磁性，由于小型磁隙区两端皆为低磁场强度区域，磁流体流动到一个低磁场强度区域时，磁流体会受到一定斥力，使得难以磁流体穿过该低磁场强度区域，流向环形磁间隙7的其他部分。磁流体与磁轭1、中央磁铁2、中央顶片3、边磁铁21及边顶片22共同组成磁路系统，可以进一步提升上述四个磁隙区9内的磁场强度，提升扬声器的音质。
相对于实施例1、2，实施例3中的五个磁铁和四个填充磁流体的磁隙区9可以提供更高的磁场强度，更好地调整扬声器的Q值，提高瞬态响应速度，有利于改善扬声器的频率响应。实施例3中磁流体的其他技术效果与实施例1、2中磁流体的技术效果相同或类似，在此不做赘述。
实施例3还提供一种如前文所述磁路系统的制造方法，包括下述步骤S1）~步骤S3）。
步骤S1）将磁铁、磁轭与顶片围成环形磁间隙。如图14所示，所述步骤S1）包括：步骤S121） 在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；步骤S122）在所述磁轭的磁轭底板上表面的边缘处贴附至少一组彼此相对的边磁铁；步骤S123）在所述中央磁铁上表面贴附中央顶片，且在所述边磁铁上表面贴附边顶片。
S2）在所述环形磁间隙内设置两个以上低磁场节点，使得所述环形磁间隙内任意两个低磁场节点之间的部分形成一个磁隙区。具体地说，在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或，在所述边顶片边缘处设置两个以上边顶片缺口，其开口方向朝向所述环形磁间隙。步骤S2）中，在设置低磁场节点之前，需要计算磁流体用量、计算低磁场节点的位置；还需要计算所述中央顶片缺口和/或所述边顶片缺口的尺寸。
S3）向至少一个磁隙区内填充磁流体，从而将磁路系统组装完成。
步骤S1）~步骤S3）之后，将音圈4、振膜5、盆架6等部件及磁路系统组装在一起，即可以生产出微型扬声器。
实施例3所述磁路系统的制造方法，可以根据需要设置低磁场节点的位置，自行调整磁路系统中的磁流体用量，从而有效调整音圈和振膜的阻尼。
本实施例优点在于，相对于实施例1、2，本实施例中的五个磁铁和四个填充磁流体的磁隙区可以提供更高的磁场强度，更好地调整扬声器的Q值，提高瞬态响应速度，有利于改善扬声器的频率响应。在音圈发生振荡时，本实施例可以减少音圈摩擦磁轭现象的发生，进而可以减少扬声器的失真，特别是高次谐波失真，可以有效改善扬声器的音质。本实施例可以有效改善音圈的散热效果，可以避免因音圈过热而导致的扬声器热损毁。本实施例的微型扬声器，可以承受更大的输入功率，可以使得微型扬声器可承受的输入功率达到原来的2倍以上。
以上详细描述了本发明的较佳具体实施例。应当理解，本领域的普通技术人员无需创造性劳动就可以根据本发明的构思作出诸多修改和变化。因此，凡本技术领域中技术人员依本发明的构思在现有技术的基础上通过逻辑分析、推理或者有限的实验可以得到的技术方案，皆应在由权利要求书所确定的保护范围内。

Claims (22)

  1. 一种磁路系统，包括
    环形磁间隙，由磁轭、磁铁、顶片围成；
    其特征在于，还包括
    两个以上低磁场节点，设于所述环形磁间隙内；
    磁隙区，其为所述环形磁间隙内任意两个低磁场节点之间的部分；以及
    磁流体，被填充于至少一个磁隙区内。
  2. 如权利要求1所述的磁路系统，其特征在于，所述磁轭包括
    磁轭底板； 以及
    磁轭侧板，设于所述磁轭底板边缘处。
  3. 如权利要求2所述的磁路系统，其特征在于，所述磁铁包括
    中央磁铁，贴附于所述磁轭底板上表面的中部；和/或
    边磁铁，贴附于所述磁轭底板上表面的边缘处。
  4. 如权利要求3所述的磁路系统，其特征在于，所述顶片包括
    中央顶片，贴附于所述中央磁铁上表面；和/或
    边顶片，贴附于所述边磁铁上表面。
  5. 如权利要求4所述的磁路系统，其特征在于，所述低磁场节点包括
    两个以上中央顶片缺口，设于所述中央顶片边缘处，其开口方向朝向所述环形磁间隙；和/或
    两个以上边顶片缺口，设于所述边顶片边缘处，其开口方向朝向所述环形磁间隙；和/或
    两个以上磁轭凹槽，设于所述磁轭侧板上端。
  6. 如权利要求5所述的磁路系统，其特征在于，
    当所述低磁场节点包括中央顶片缺口、边顶片缺口和/或磁轭凹槽时，
    每一中央顶片缺口的位置与一个边顶片缺口和/或一个磁轭凹槽的位置彼此对应。
  7. 如权利要求1所述的磁路系统，其特征在于，所述磁轭包括磁轭底板。
  8. 如权利要求7所述的磁路系统，其特征在于，所述磁铁包括
    中央磁铁，贴附于所述磁轭底板上表面的中部；
    边磁铁，贴附于所述磁轭底板上表面的边缘处。
  9. 如权利要求8所述的磁路系统，其特征在于，所述顶片包括
    中央顶片，贴附于所述中央磁铁上表面；
    边顶片，贴附于所述边磁铁上表面。
  10. 如权利要求9所述的磁路系统，其特征在于，
    所述低磁场节点包括
    两个以上中央顶片缺口，设于所述中央顶片边缘处，其开口方向朝向所述环形磁间隙；和/或
    两个以上边顶片缺口，设于所述边顶片边缘处，其开口方向朝向所述环形磁间隙。
  11. 如权利要求9所述的磁路系统，其特征在于，
    当所述低磁场节点包括中央顶片缺口和边顶片缺口时，
    每一中央顶片缺口的位置与一个边顶片缺口的位置彼此对应。
  12. 如权利要求1所述的磁路系统，其特征在于，
    填充有所述磁流体的磁隙区为轴对称图形，其对称轴为所述环形磁间隙的一中心线。
  13. 一种微型扬声器，包括权利要求1-12中任一项所述的磁路系统。
  14. 如权利要求13所述的微型扬声器，其特征在于，
    所述微型扬声器还包括音圈，设于所述环形磁间隙内；
    所述磁流体填充于所述音圈两侧和/或其底部；
    所述磁流体粘附于所述磁轭和/或所述磁铁和/或所述顶片的边缘处。
  15. 如权利要求13所述的微型扬声器，其特征在于，
    所述微型扬声器包括但不限于平板形振膜扬声器、圆锥形振膜扬声器或球顶形扬声器。
  16. 一种如权利要求1所述的磁路系统的制造方法，其特征在于，包括如下步骤：
    将磁铁、磁轭与顶片围成环形磁间隙；
    在所述环形磁间隙内设置两个以上低磁场节点，所述环形磁间隙内任意两个低磁场节点之间的部分形成一个磁隙区；以及
    向至少一个磁隙区内填充磁流体。
  17. 如权利要求16所述的磁路系统的制造方法，其特征在于，
    将磁轭、磁铁与顶片围成环形磁间隙的步骤，包括如下步骤：
    在所述磁轭的磁轭底板上表面的边缘处设置磁轭侧板；
    在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；以及
    在所述中央磁铁上表面贴附中央顶片。
  18. 如权利要求17所述的磁路系统的制造方法，其特征在于，
    在所述环形磁间隙内设置两个以上低磁场节点的步骤，包括如下步骤：
    在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或
    在所述磁轭侧板上端设置两个以上磁轭凹槽。
  19. 如权利要求18所述的磁路系统的制造方法，其特征在于，
    将磁铁、磁轭与顶片围成环形磁间隙的步骤中，还包括如下步骤：
    在所述磁轭的磁轭底板上表面的边缘处贴附至少一组彼此相对的边磁铁；以及
    在所述边磁铁上表面贴附边顶片。
  20. 如权利要求19所述的磁路系统的制造方法，其特征在于，
    在所述环形磁间隙内设置两个以上低磁场节点的步骤，包括如下步骤：
    在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或
    在所述边顶片边缘处设置两个以上边顶片缺口，其开口方向朝向所述环形磁间隙；和/或
    在所述磁轭侧板上端设置两个以上磁轭凹槽。
  21. 如权利要求16所述的磁路系统的制造方法，其特征在于，
    将磁铁、磁轭与顶片围成环形磁间隙的步骤，包括如下步骤：
    在所述磁轭的磁轭底板上表面的中部贴附中央磁铁；
    在所述磁轭的磁轭底板上表面的边缘处贴附至少一组彼此相对的边磁铁；以及
    在所述中央磁铁上表面贴附中央顶片，且在所述边磁铁上表面贴附边顶片。
  22. 如权利要求21所述的磁路系统的制造方法，其特征在于，
    在所述环形磁间隙内设置两个以上低磁场节点的步骤，包括如下步骤：
    在所述中央顶片边缘处设置两个以上中央顶片缺口，其开口方向朝向所述环形磁间隙；和/或
    在所述边顶片边缘处设置两个以上边顶片缺口，其开口方向朝向所述环形磁间隙。
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