CN115884054A - Magnetic circuit unit and loudspeaker using same - Google Patents

Abstract

The invention discloses a magnetic circuit unit and a loudspeaker using the magnetic circuit unit, comprising: a permanent magnet made of rare earth material, a U-iron, and a washer; the permanent magnet is placed in an accommodating groove of the U-iron; The center of the permanent magnet is provided with a concave part; the washer covers the surface of the permanent magnet away from the bottom. The permanent magnet is roughly a cylinder, and the depression is roughly a cylinder-shaped through hole; the axis of the permanent magnet coincides with the axis of the depression; the washer is in a ring shape. The diameter length of the recessed part is 20%-70% of the diameter length of the permanent magnet. The diameter length of the concave part is 35% of the diameter length of the permanent magnet. The number of the permanent magnets is two, which includes an outer magnet and an inner magnet; the center of the outer magnet is provided with an accommodation portion covering the inner magnet; the grade of the outer magnet is larger than the The grade of the inner layer magnet; the whole body of the inner layer magnet is solid or a cavity is opened in the center.

Description

A magnetic circuit unit and a loudspeaker using the magnetic circuit unit

technical field

The present application relates to the technical field of loudspeaker devices, in particular to a magnetic circuit unit and a loudspeaker using the magnetic circuit unit.

Background technique

Divided from the structure of the speaker, the speaker can be roughly divided into an external magnetic speaker and an internal magnetic speaker; both of these two speakers include a magnetic circuit unit; The magnetically conductive part of the magnetic speaker is U iron; the magnetically conductive part is also used to place the magnet, which is a key component in the magnetic circuit of the speaker unit and determines the performance of the speaker.

T has an iron core, so the permanent magnet corresponding to the T iron will be equipped with a corresponding avoidance channel; the magnetically conductive component is the internal magnetic speaker of the U iron, in the inherent cognition of those skilled in the art, the U The permanent magnet in the iron does not require additional modification, it only needs to be placed in the groove of the U iron as a whole.

Thanks to the use of permanent magnets made of rare earth materials in internal magnetic speakers, internal magnetic speakers can be made smaller in size and better in performance than other types of speakers, but the price of permanent magnets made of rare earth materials continues to rise. The contained rare earth elements are still non-renewable resources, and the mining of rare earth mines also causes serious environmental pollution.

In the magnetic circuit design of the internal magnetic speaker, the structure of the whole rare earth magnet is not optimized to reduce the material cost of the speaker.

Contents of the invention

The present invention mainly aims at the above problems, and proposes a magnetic circuit unit and a loudspeaker using the magnetic circuit unit, aiming to solve the technical problems in the background art.

In order to achieve the above object, the present invention provides a magnetic circuit unit, comprising: a permanent magnet made of rare earth material, a U-iron, and a washer; the permanent magnet is placed in the accommodation groove of the U-iron; the permanent magnet A concave part is opened in the center of the magnet; the washer covers the surface of the permanent magnet away from the bottom.

Further, the permanent magnet is roughly a cylinder, and the depression is roughly a cylinder-shaped through hole; the axis of the permanent magnet coincides with the axis of the depression; and the washer is ring-shaped.

Further, the diameter of the recessed portion is 20% to 70% of the diameter of the permanent magnet.

Further, the diameter of the recessed portion is 35% of the diameter of the permanent magnet.

Further, the number of the permanent magnets is two, which include an outer magnet and an inner magnet; the center of the outer magnet is provided with an accommodation portion covering the inner magnet; The grade is greater than that of the inner magnet; the inner magnet is solid or has a cavity in the center.

Further, the number of the permanent magnets is multiple, which includes an outer magnet and a plurality of inner magnets surrounded by each other; the center of the outer magnet is provided with an accommodation portion covering a plurality of the inner magnets Among the outermost inner layer magnets; the grade of the outer layer magnets is greater than the grades of the multiple inner layer magnets; the grade of the relatively outer magnets among the multiple inner layer magnets is greater than the grades of the ring sleeves Describe the brand name of the inner layer magnet.

Further, the innermost magnet among the plurality of inner magnets is solid or has a cavity in the center.

A magnetic circuit unit, comprising a permanent magnet made of rare earth material, a U-iron, and a washer; the permanent magnet is roughly a cuboid; the permanent magnet is placed in the accommodation groove of the U-iron; the permanent magnet The magnet includes a middle magnet and one or more side magnets arranged side by side on both sides of the middle magnet; the grade of the side magnet is larger than that of the middle magnet, and the washer covers the permanent magnet. The magnet faces away from the surface of the bottom.

A loudspeaker using the aforementioned magnetic circuit unit.

Compared with the prior art, the magnetic circuit unit provided by the present invention and the loudspeaker using the magnetic circuit unit can be provided with recesses by the permanent magnet in the magnetic circuit unit of the magnetic circuit unit of the inner magnetic loudspeaker. In order to reduce the use of rare earth magnets such as permanent magnets, the cost of the magnetic circuit unit is reduced, and the pollution caused by rare earth mining is also reduced to a certain extent.

Description of drawings

Fig. 1 is a cross-sectional view of a conventional internal magnetic loudspeaker magnetic circuit unit.

FIG. 2 is a schematic diagram of a three-dimensional structure of an embodiment of a magnetic circuit unit of the present application.

FIG. 3 is a cross-sectional view of FIG. 3 .

Fig. 4 is a cross-sectional view of a permanent magnet with a diameter of 28.4 mm in the magnetic circuit unit of the present application when the size of the concave part is a through hole of 20 mm.

Fig. 5 is a sectional view of a permanent magnet in a magnetic circuit unit of the present application divided into two, an outer magnet and an inner magnet.

Fig. 6 is a cross-sectional view of another embodiment of a magnetic circuit unit in which the permanent magnet is divided into two, an outer magnet and an inner magnet.

Fig. 7 is a cross-sectional view of a permanent magnet in a magnetic circuit unit of the present application divided into two, an outer magnet and an inner magnet, and the inner magnet is provided with a cavity.

Fig. 8 is a cross-sectional view of a magnetic circuit unit of the present application when there are multiple permanent magnets, which includes an outer magnet and two inner magnets surrounded by each other.

FIG. 9 is a perspective structural diagram of an embodiment in which the permanent magnet is a cuboid in a magnetic circuit unit of the present application.

FIG. 10 is a cross-sectional view of FIG. 9 .

Fig. 11 is a perspective view of another embodiment of a rectangular parallelepiped permanent magnet in a magnetic circuit unit of the present application.

FIG. 12 is a cross-sectional view of FIG. 11 .

Fig. 13 is a cross-sectional view of another embodiment of a rectangular parallelepiped permanent magnet in a magnetic circuit unit of the present application.

Fig. 14 is a magnetic field distribution diagram of a conventional internal magnetic loudspeaker magnetic circuit unit with a diameter of 28.4 mm, a thickness of 6 mm, and a brand of N40 magnet.

FIG. 15 is a graph showing the magnetic induction in the magnetic gap of the magnet in FIG. 14 .

Fig. 16 is a magnetic field distribution diagram of a permanent magnet with a diameter of 28.4 mm and a thickness of 6 mm in a magnetic circuit unit of the present application, which is a permanent magnet of the brand N40, and the concave part is a cylindrical through hole with a diameter of 6 mm.

Fig. 17 is a magnetic field distribution diagram of a permanent magnet with a diameter of 28.4 mm and a thickness of 6 mm in a magnetic circuit unit of the present application, the brand is N40, and the concave part is a cylindrical through hole with a diameter of 10 mm.

Fig. 18 is a magnetic field distribution diagram of a permanent magnet with a diameter of 28.4 mm and a thickness of 6 mm in a magnetic circuit unit of the present application, the brand is N40, and the concave part is a cylindrical through hole with a diameter of 20 mm.

FIG. 19 is a comparative graph of magnetic induction in the magnetic gap of the magnets in FIGS. 14-18 .

Fig. 20 is a magnetic field distribution diagram of a permanent magnet with a thickness of 6 mm in the magnetic circuit unit of the present application, the outer magnet of the brand N40 with an outer diameter of 28.4 mm, and the housing part is provided with an inner magnet with an outer diameter of 10 mm of the brand N35.

Fig. 21 is a magnetic field distribution diagram of a permanent magnet with a thickness of 6 mm in the magnetic circuit unit of the present application, the outer magnet with an outer diameter of 28.4 mm, grade N40, and the housing part is provided with an inner layer magnet with an outer diameter of 20 mm, grade N35.

22 is a magnetic field distribution diagram of a permanent magnet with a thickness of 6 mm in the magnetic circuit unit of the present application, the outer magnet with an outer diameter of 28.4 mm, grade N40, and the housing part is provided with an inner layer magnet with an outer diameter of 20 mm, grade N32.

Fig. 23 is a comparative graph of the magnetic induction in the magnetic gap of the magnets in Fig. 14, Fig. 18, Fig. 20-Fig. 22.

Fig. 24 is a permanent magnet with a thickness of 6 mm in the magnetic circuit unit of the present application. The outer magnet has an outer diameter of 28.4 mm, grade N40, and its accommodation part is provided with an inner layer magnet with an outer diameter of 10 mm. Magnetic field diagram of a magnet.

Figure 25 is a magnetic circuit unit of the present application with a permanent magnet with a thickness of 6 mm. The outer magnet has an outer diameter of 28.4 mm. The brand N40 has an inner magnet with an outer diameter of 10 mm. The brand N35 has a cylindrical cavity magnet with a diameter of 10 mm. The magnetic field distribution map.

Fig. 26 is a comparative graph of the magnetic induction in the magnetic gap of the magnets in Fig. 14, Fig. 18, Fig. 20-Fig. 22, Fig. 24 and Fig. 25.

Reference signs shown in the figure: 1, permanent magnet; 101, recessed part; 110, outer magnet; 120, inner magnet; 121, cavity; 130, middle magnet; 140, side magnet; 2, U iron; 3, Huasi.

Detailed ways

Please refer to Fig. 2-Fig. 6, Fig. 14-Fig. 26, this embodiment provides a magnetic circuit unit, including a permanent magnet 1 made of rare earth material, a U iron 2, and a washer 3; the permanent magnet 1 is placed In the accommodating groove of the U iron 2; the center of the permanent magnet 1 is provided with a recessed portion 101; the washer 3 covers the surface of the permanent magnet 1 away from the bottom.

When the permanent magnet 1 was improved and tested, it was found that the magnetic field strength of the central part of the permanent magnet 1 and the Washer 3 was significantly lower than that of the surrounding area, so the central part of the permanent magnet 1 and the Washer 3 was excavated to form a depression Part 101, the magnetic field strength provided by the permanent magnet 1 and Washer 3 is to a certain extent compared with the magnetic field strength of the permanent magnet 1 as a whole, within an acceptable range, and has an impact on the performance of the magnetic circuit unit Also within the acceptable range. The recessed portion 101 may be a through hole or a blind hole.

Through the internal magnetic speaker, the permanent magnet 1 in the magnetic circuit unit of the U-iron 2 is provided with a recessed part 101 to reduce the amount of magnets used in the permanent magnet 1, which is a rare earth material, and reduce the weight of the magnetic circuit unit. The cost has also reduced the pollution caused by rare earth mining to a certain extent.

Setting the recessed part 101 on the permanent magnet 1 not only reduces the use of materials and reduces the cost, but the presence of the recessed part 101 also reduces the weight of the magnetic circuit unit, making the speaker lighter and easier to transport and carry, and increases the permanent magnet 1 surface area, because when the loudspeaker is working at high power, it will generate heat, which will cause high temperature in the magnetic gap part, which may cause irreversible magnetic loss to the magnet made of rare earth material, and the magnet will slowly demagnetize until there is no magnetism, and the concave part 101 makes the permanent The surface area of the magnet 1 is increased, which reduces heat energy storage, makes it easier for the permanent magnet 1 to dissipate heat, and prolongs the service life of the permanent magnet 1 .

Please refer to Fig. 3-Fig. 4, the permanent magnet 1 is roughly a cylinder, and the concave portion 101 is roughly a cylindrical through hole; the axis of the permanent magnet 1 coincides with the axis of the concave portion 101; the Washer 3 is ring-shaped.

The washer 3 corresponds to the permanent magnet 1. After the permanent magnet 1 is provided with a cylindrical through hole, the washer 3 adopts a ring shape corresponding to the concave portion 101, and the magnetic field strength of the central part of the permanent magnet 1 and the washer 3 is lower than Periphery, so the washer 3 is designed in a ring shape, and the impact on the performance of the magnetic circuit unit is also within an acceptable range.

Please refer to FIGS. 3-4 , 16-19 , in some embodiments, the diameter of the recessed portion 101 is 20%-70% of the diameter of the permanent magnet 1 .

Taking a cylindrical rare-earth magnet with a brand name of N40, a diameter of 28.4 mm, and a thickness of 6 mm as an example, after testing, the center of the magnet is respectively dug out with a depression 101 with a diameter of 6 mm, 10 mm, and 20 mm. The magnetic field strength of this magnet is analyzed and compared again, curve a, curve b, curve c, curve d correspond respectively to the magnet as a whole block structure, the depression 101 is 6 millimeters, the depression 101 is 10 millimeters, and the depression 101 is 10 millimeters. The magnetic induction intensity in the millimeter magnetic gap, and then these permanent magnets 1 are applied to the magnetic circuit unit, assembled into a loudspeaker, and tested and compared. Within an acceptable range, the diameter length of the concave portion 101 is the diameter of the permanent magnet 1 When the length is less than 35%, from an acceptable level, the impact on the overall performance of the loudspeaker is relatively low.

Preferably, the diameter of the recessed portion 101 is 35% of the diameter of the permanent magnet 1 .

After repeated testing and selection, the diameter and length of the recessed portion 101 that can reduce the amount of magnets used, reduce the cost, and ensure the magnetic induction of the permanent magnet 1 is less than 35% of the diameter of the permanent magnet 1 .

Please refer to FIG. 5-FIG. 7, the number of the permanent magnet 1 is two, which includes an outer magnet 110 and an inner magnet 120; The layer magnet 120; the grade of the outer layer magnet 110 is greater than the grade of the inner layer magnet 120; the whole body of the inner layer magnet 120 is solid or has a cavity in the center.

In some embodiments, the accommodating portion is a cylindrical through hole, or a blind hole, and the accommodating portion is the concave portion 101 of the original single permanent magnet 1 .

The grade of magnet made of rare earth material is positively correlated with its selling price, the higher the grade, the more expensive the selling price. It is not an optimal design to only set the recessed part 101 in the permanent magnet 1, because the distribution of the magnetic field strength of the magnet from the center to the periphery is continuous from weak to strong, and according to this rule, magnets of different grades are used to distribute from the center to the edge arrangement, the grade of the outer magnet 110 is set to be greater than the grade of the inner magnet 120, and for the permanent magnet 1 provided with the recessed portion 101, the inner layer magnet 120 of a relatively lower grade is filled in the recessed portion 101. The low magnetic induction intensity caused by the empty recessed portion 101 is compensated to achieve the highest cost performance.

Please refer to Fig. 14, Fig. 18, Fig. 20-Fig. 23, the grade of the outer magnet 110 is N40, and the grade of the inner magnet 120 is N35, N32. Combination comparison is carried out in the recessed portion 101, the grades of the outer magnets 110 are all N40, and the diameter is 28.4 millimeters; the curve e is the magnetic induction intensity in the magnetic gap where the permanent magnet 1 adopts a whole piece of N40 grade magnet, and the curve f is the permanent magnet The magnetic induction intensity in the magnetic gap with a diameter of 6 millimeters in the concave portion 101 of 1, the curve g is the magnetic induction intensity in the magnetic gap with a diameter of 10 millimeters in the concave portion 101 of the permanent magnet 1, and the curve h is the through hole of the outer magnet 110 The diameter is 10 millimeters, and the inner layer magnet 120 grade is the magnetic induction intensity in the magnetic gap of N35, and the curve i is that the through hole diameter of the outer layer magnet 110 is 20 millimeters, and the inner layer magnet 120 grade is the magnetic induction intensity in the magnetic gap of N35, Curve j is the magnetic induction intensity in the magnetic gap where the diameter of the through hole of the outer layer magnet 110 is 20 mm, and the grade of the inner layer magnet 120 is N32. strength.

After comparative analysis, except that the curve g deviates more from the curve e than the curve k, other scheme combinations are close to the curve e. Therefore, a low-cost scheme can be selected to replace the permanent magnet 1 with a whole piece of high-grade magnet. In order to achieve the highest cost performance.

The scheme corresponding to the curve h and the curve i shows that the loss of the magnetic field intensity of these two designs is relatively small, and it is basically maintained between the permanent magnet 1 without the recessed part 101 and the opening of the recessed part 101 at 6 mm, which is a more preferred solution.

Please refer to Fig. 8, the quantity of described permanent magnet 1 is a plurality of, and it comprises an outer layer magnet 110 and the inner layer magnet 120 of a plurality of mutual loop; The inner magnet 120 of the outermost layer among the inner magnets 120; the grade of the outer magnet 110 is greater than the grade of the plurality of inner magnets 120; the outermost of the plurality of inner magnets 120 The grade of the magnet of the layer is greater than that of the inner layer magnet 120 surrounded by it.

Referring to FIG. 7 , the innermost magnet among the plurality of inner magnets 120 is solid or has a cavity in the center.

The number of inner layer magnets 120 is provided in multiples, which are mutually encircled, so as to reduce the consumption of high-grade and high-priced permanent magnets 1 , reduce material costs, and improve the cost performance of the magnetic circuit unit.

Please refer to Fig. 14, Fig. 18, Fig. 20-Fig. 22, Fig. 24- Fig. 26, the grade of outer magnet 110 is N40, and the grade of inner magnet 120 is N35, N32. The inner layer magnet 120 is built into the recessed portion 101 for combination comparison, and the outer layer magnet 110 is all N40, with a diameter of 28.4 millimeters; Curve 1 is the magnetic induction intensity in the magnetic gap of the permanent magnet 1 adopting the whole N40 brand magnet, Curve m is the magnetic induction intensity in the magnetic gap in which the diameter of the concave portion 101 of the permanent magnet 1 is 6 millimeters, the curve n is the magnetic induction intensity in the magnetic gap in which the diameter of the concave portion 101 of the permanent magnet 1 is 10 millimeters, and the curve o is the outer The through-hole diameter of the layer magnet 110 is 10 millimeters, and the magnetic induction intensity in the magnetic gap of the inner layer magnet 120 grade is N35. The magnetic induction intensity in the gap, the curve q is the magnetic induction intensity in the magnetic gap where the diameter of the through hole of the outer layer magnet 110 is 20 mm and the grade of the inner layer magnet 120 is N32; the curve r is the outer layer magnet 110 surrounded by two inner layer magnets 120, the diameter of the innermost inner layer magnet 120 is 10 mm, the grade is N32, and the inner layer magnet 120 of the innermost layer of the inner layer magnet 120 and the outer layer magnet 110 is a ring-shaped magnetic gap with a width of 5 mm and the grade is N35 The magnetic induction intensity in; Curve s is the through-hole diameter of outer layer magnet 110 is 15 millimeters, the grade of inner layer magnet 120 is N35, and the through-hole diameter of inner layer magnet 120 is the magnetic induction intensity in the magnetic gap of 10 millimeters; Curve t is the magnetic induction intensity in the magnetic gap where the diameter of the concave portion 101 of the permanent magnet 1 is 20 mm.

The scheme corresponding to the curve r shows that the loss of the magnetic field intensity of the three inner layer magnets 120 that are set around each other is also basically maintained between no opening and the 6 mm recess 101; if the centermost N32 inner layer magnet 120 is removed, That is to say, for the scheme corresponding to the curve s, the central value is only 1.5% lower than that of the design with a 10mm through hole.

Therefore, this low-cost solution can be selected to replace the permanent magnet 1 with a whole piece of high-grade magnet to achieve the highest cost performance.

It is worth noting that, in order to facilitate the understanding of the above description, the depression 101 is expressed as being dug out from the permanent magnet 1, and it does not mean that the depression 101 is drilled and drilled from the entire permanent magnet 1 in the later stage. Rather, when the recessed portion 101 is sintered together with the permanent magnet 1 , the recessed portion 101 is formed plastically by the mold, not secondary processing.

Please refer to FIG. 7-FIG. 13, a magnetic circuit unit, including a permanent magnet 1 made of rare earth material, a U iron 2, and a washer 3; the permanent magnet 1 is roughly a cuboid; the permanent magnet 1 is placed in the In the accommodating groove of the U iron 2; the permanent magnet 1 includes a middle magnet 130 and one or more side magnets 140 arranged side by side on both sides of the middle magnet 130; the side magnets 140 The grade is greater than that of the middle magnet 130 , and the washer 3 covers the surface of the permanent magnet 1 away from the bottom.

This magnetic circuit unit is applied to the situation when the loudspeaker is square as a whole, so as to prevent the permanent magnet 1 from being set in the magnetic circuit unit as a whole, reduce the usage of rare earth magnets such as the permanent magnet 1, and reduce the magnetic The cost of the road unit also reduces the pollution caused by rare earth mining to a certain extent.

The present invention also provides a loudspeaker using the aforementioned magnetic circuit unit.

Claims (10)

1. A magnetic circuit unit, characterized in that it comprises a permanent magnet made of rare earth material, a U iron, and a washer; the permanent magnet is placed in the accommodation groove of the U iron; the center of the permanent magnet is opened There is a concave part; the washer is covered on the surface of the permanent magnet away from the bottom. 2. A magnetic circuit unit according to claim 1, characterized in that, the permanent magnet is approximately a cylinder, and the recess is approximately a cylindrical through hole; the axis of the permanent magnet is in line with the The axes of the depressions are coincident; the washers are ring-shaped. 3 . The magnetic circuit unit according to claim 2 , wherein the diameter of the recessed portion is 20% to 70% of the diameter of the permanent magnet. 4 . 4 . The magnetic circuit unit according to claim 3 , wherein the diameter of the recessed portion is 35% of the diameter of the permanent magnet. 5. A kind of magnetic circuit unit according to claim 2, is characterized in that, the quantity of described permanent magnet is two, and it comprises an outer layer magnet and an inner layer magnet; The center of described outer layer magnet is provided with The accommodating part covers the inner magnet; the brand of the outer magnet is larger than that of the inner magnet; the inner magnet is solid or has a cavity in the center. 6. A magnetic circuit unit according to claim 2, characterized in that, the number of the permanent magnets is multiple, which includes an outer magnet and a plurality of inner magnets that are surrounded by each other; The center of the layer magnet is provided with an accommodation portion covering the outermost inner layer magnet among the plurality of inner layer magnets; the grade of the outer layer magnet is larger than the grade of the plurality of inner layer magnets; The grade of the relatively outer magnet in the layer magnet is larger than the grade of the inner magnet surrounded by it. 7 . The magnetic circuit unit according to claim 6 , wherein the innermost magnet among the plurality of inner magnets is solid or has a cavity in the center. 8 . 8. A magnetic circuit unit, characterized in that it comprises a permanent magnet made of rare earth material, a U iron, and a washer; the permanent magnet is roughly a cuboid; the permanent magnet is placed in the accommodation groove of the U iron In; the permanent magnet includes a middle magnet and one or more side magnets arranged side by side on both sides of the middle magnet; the grade of the side magnet is greater than the grade of the middle magnet, and the washer Cover the surface of the permanent magnet facing away from the bottom. 9. A loudspeaker, characterized in that the magnetic circuit unit according to any one of claims 1-7 is used. 10. A loudspeaker, characterized in that the magnetic circuit unit as claimed in claim 8 is used.

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