Magnetic circuit unit and vehicle-mounted loudspeaker

Abstract

The utility model discloses a magnetic circuit unit and a vehicle-mounted loudspeaker. The magnetic circuit unit of the loudspeaker comprises a magnetic conductive piece, a mounting groove is arranged in the magnetic conductive piece, the magnetic circuit unit comprises a plurality of magnetic steel sheets, the plurality of magnetic steel sheets are arranged in the mounting groove and are mutually spliced into closed annular magnetic steel, and the magnetic steel sheets are arranged in the mounting groove. A magnetic gap for insertion of a voice coil of the loudspeaker is formed between the annular magnetic steel and the surface of the magnetic conductive member. The magnetic circuit unit of the loudspeaker is beneficial for improving the sensitivity of the loudspeaker, reducing the distortion of the loudspeaker and simultaneously being beneficial for the heat dissipation of the voice coil.

Description

Technical Field

[0001] This utility model belongs to the field of loudspeakers, specifically relating to a magnetic circuit unit for a loudspeaker and a vehicle loudspeaker using the magnetic circuit unit. Background Technology

[0002] The magnetic circuit unit is a crucial component of a moving-coil loudspeaker, providing the driving force for the voice coil and cone vibration system. It typically includes a magnetic conductor and a magnet, and in some cases, a front panel. The magnet plays a vital role in driving the magnetic circuit unit. Currently, most traditional electrodynamic loudspeakers use axial magnetic circuits, employing a single, integrated toroidal or circular magnet—a common structural form in the industry. This design, to some extent, results in low magnetic field energy conversion efficiency and low sensitivity. Furthermore, this structure leads to uneven magnetic flux density distribution, increasing the likelihood of nonlinear distortion.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0004] This invention provides an improved magnetic circuit unit for a loudspeaker, which improves loudspeaker sensitivity, reduces distortion, and facilitates voice coil heat dissipation. This invention also provides a vehicle loudspeaker using this magnetic circuit unit, which features high sensitivity, low distortion, and good voice coil heat dissipation.

[0005] The present invention adopts the following technical solution:

[0006] A magnetic circuit unit for a loudspeaker includes a magnetic guide with a mounting groove. The magnetic circuit unit includes a plurality of magnets disposed in the mounting groove and joined together to form a closed annular magnet. A magnetic gap is formed between the annular magnet and the surface of the magnetic guide for the insertion of a voice coil of the loudspeaker.

[0007] In a preferred embodiment, one of the ring magnets is formed by splicing together 3 to 10 of the magnet sheets.

[0008] In a more preferred embodiment, one of the ring magnets is formed by splicing together four, six or eight of the magnet sheets.

[0009] In a preferred embodiment, each of the magnetic steel sheets includes an opposite top surface and a bottom surface, and a plurality of side surfaces located between the top surface and the bottom surface, at least one of the side surfaces being fixedly connected to the magnetic conductor, and the top surface and / or the bottom surface being fan-shaped.

[0010] In a more preferred embodiment, the mounting groove includes a stepped surface, a first sidewall and a second sidewall, the first sidewall being located around the second sidewall, the stepped surface extending laterally from the first sidewall toward the second sidewall, one side of the magnet being fixedly connected to the first sidewall, the bottom surface of the magnet being fixedly connected to the stepped surface, and the magnetic gap including the space between the magnet and the second sidewall.

[0011] In a further preferred embodiment, the mounting groove further includes a third sidewall opposite to the second sidewall, the third sidewall being located around the second sidewall, the stepped surface connecting the first sidewall and the third sidewall, and the magnetic gap further including the space between the third sidewall and the first sidewall.

[0012] In a further preferred embodiment, the mounting groove is generally annular, the distance between the first sidewall and the second sidewall is greater than the distance between the third sidewall and the second sidewall, and the height of the first sidewall is greater than or equal to the height of the magnet sheet.

[0013] In a preferred embodiment, the magnetic conductor has opposite first and second surfaces. The mounting groove includes a first mounting groove formed on the first surface and a second mounting groove formed on the second surface. The orthographic projections of the first and second mounting grooves onto the first or second surface are concentric rings and the distance between them is greater than zero. The depth of the first or second mounting groove is greater than half the distance between the first and second surfaces. The first and second mounting grooves are respectively provided with annular magnets formed by splicing multiple magnetic steel sheets. The outer diameter of one annular magnet is smaller than the inner diameter of another annular magnet. The ratio of the thickness of the magnetic steel sheet to the outer diameter of the annular magnet is 1:(4-50).

[0014] In a preferred embodiment, the magnetic conductive element is integrally formed from an iron block, and the material of the magnetic steel sheet is a rare earth permanent magnet material; the magnetic steel sheet is bonded to the magnetic conductive element, and / or, adjacent magnetic steel sheets are bonded to each other.

[0015] This utility model also adopts the following technical solution:

[0016] A loudspeaker includes a diaphragm and a voice coil connected to the diaphragm, the loudspeaker further including a magnetic circuit unit of the loudspeaker as described above, the voice coil being movably inserted into a magnetic gap in the magnetic circuit unit.

[0017] The present invention adopts the above solution and has the following advantages compared with the prior art:

[0018] The magnetic circuit unit of this invention effectively reduces speaker distortion, provides more uniform magnetic flux density, and achieves higher energy conversion, thus improving speaker sensitivity. The resulting vehicle speaker exhibits low distortion, high sensitivity, and better voice coil heat dissipation; it also reduces overall height and interior space occupancy. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an exploded view of a magnetic circuit unit according to Embodiment 1 of the present invention.

[0021] Figure 2 This is a cross-sectional view of a magnetic circuit unit according to Embodiment 1 of the present invention.

[0022] Figure 3 This is a perspective view of a vehicle speaker according to Embodiment 2 of the present invention.

[0023] Figure 4 This is a front view of a vehicle speaker according to Embodiment 2 of the present invention.

[0024] Figure 5 This is a top view of a vehicle speaker according to Embodiment 2 of the present invention.

[0025] Figure 6 This is an exploded view of a vehicle speaker according to Embodiment 2 of the present invention.

[0026] Figure 7 This is a structural diagram of a bracket according to Embodiment 2 of the present invention.

[0027] Figure 8 This is a structural diagram of half of a vehicle speaker according to Embodiment 2 of the present invention.

[0028] Figure 9 This is a cross-sectional view of a vehicle speaker according to Embodiment 2 of the present invention.

[0029] Figure 10 This is a schematic diagram of the magnetic circuit unit used in a car speaker for comparison.

[0030] Figure 11 The distortion curves are for the vehicle speakers of Example 2 and the comparative example.

[0031] Figure 12a and Figure 12bThese are magnetic field diagrams of the magnetic circuit unit in Example 1 and the magnetic circuit unit in the comparative example, respectively.

[0032] In the above attached figures,

[0033] 1. Support; 11. Cylinder; 111. Through hole; 12. Fixing ring;

[0034] 21. First diaphragm; 22. Second diaphragm;

[0035] 31. First voice coil; 32. Second voice coil;

[0036] 41. First wave; 42. Second wave;

[0037] 5. Magnetic circuit unit; 51. Magnetic conductor; 51a. First surface; 51b. Second surface; 510. Magnetic gap; 511. First mounting groove; 512. Second mounting groove; 513. Stepped surface; 514. First sidewall; 515. Second sidewall; 516. Third sidewall; 520. Magnet sheet; 521. First annular magnet; 522. Second annular magnet;

[0038] 6. Dust cap. Detailed Implementation

[0039] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] In this article, the directional terms "up," "down," and "horizontal" are used to help those skilled in the art understand the structure of the loudspeaker and its magnetic circuit unit, and are not intended to limit the state of the loudspeaker and its magnetic circuit unit after installation in the usage scenario. For example, the loudspeaker can be installed on a horizontal, inclined, or vertical surface of a vehicle.

[0041] Figures 1 to 9 The diagrams are drawn to scale. To keep the instructions concise, the proportions of each component are not listed individually. However, the proportions and positions of each component should be considered part of the contents of this instruction manual.

[0042] Example 1 – Magnetic Circuit Unit

[0043] Figures 1 to 2 A magnetic circuit unit 5 for a loudspeaker is shown, particularly a magnetic circuit unit 5 suitable for a vehicle loudspeaker. (See reference...) Figure 1 and Figure 2As shown, the magnetic circuit unit 5 of the loudspeaker includes a magnetic guide 51 and multiple magnetic steel sheets 520. The magnetic guide 51 has a mounting groove. The magnetic circuit unit 5 includes multiple magnetic steel sheets 520, which are disposed in the mounting groove and joined together to form a closed annular magnet. A magnetic gap 510 is formed between the annular magnet and the surface of the magnetic guide 51 for the insertion of the loudspeaker's voice coil. An annular magnet can be formed by joining 3 to 10 magnetic steel sheets 520. Further, an annular magnet can be formed by joining 4, 6, or 8 magnetic steel sheets 520. Different annular magnets can use the same or different magnetic steel sheets 520.

[0044] like Figure 1 and Figure 2 In the specific example shown, the magnetic conductor 51 has a first surface 51a, on which a first mounting groove 511 is formed. The first mounting groove 511 contains m magnetic steel pieces 520, which are joined together to form a closed first annular magnet 521. A magnetic gap 510 for inserting a voice coil is formed between the first annular magnet 521 and the inner surface of the magnetic conductor 51. Further, the magnetic conductor 51 has a second surface 51b opposite to the first surface 51a, on which a second mounting groove 512 is formed. The second mounting groove 512 contains n magnetic steel pieces 520, which are joined together to form a closed second annular magnet 522. A magnetic gap 510 for inserting another voice coil is formed between the second annular magnet 522 and the inner surface of the magnetic conductor 51. m and n are positive integers greater than 1. m is a positive integer between 3 and 10, and n is a positive integer between 3 and 10. Specifically, in this embodiment, m = 4 and n = 6. In this embodiment, the magnetic sheet 520 constituting the first annular magnet 521 and the magnetic sheet 520 constituting the second annular magnet 522 have different shapes and sizes. If the first annular magnet 521 and the second annular magnet 522 have the same shape and size, then both can use magnetic sheets 520 of the same specification.

[0045] Each magnet sheet 520 includes an opposite top surface and a bottom surface, and multiple side surfaces located between the top and bottom surfaces. At least one side surface is fixedly connected to the magnetic conductor 51. The top surface and / or the bottom surface is fan-shaped. Specifically, in this embodiment, the overall shape of the magnet sheet 520 is similar to a tile, wherein two side surfaces are arc surfaces, and the top and bottom surfaces are parallel planes with identical shapes and sizes, forming fan-shaped rings with equal areas.

[0046] The first mounting groove 511 includes a stepped surface 513, a first sidewall 514 and a second sidewall 515, the first sidewall 514 is located on the periphery of the second sidewall 515, the stepped surface 513 extends laterally from the first sidewall 514 toward the second sidewall 515, one side of the magnet 520 is fixedly connected to the first sidewall 514, the bottom surface of the magnet 520 is fixedly connected to the stepped surface 513, and the magnetic gap 510 includes the space between the magnet 520 and the second sidewall 515.

[0047] Similar to the first mounting groove 511, the second mounting groove 512 also includes a stepped surface 513, a first sidewall 514 and a second sidewall 515, the first sidewall 514 being located around the second sidewall 515, the stepped surface 513 extending laterally from the first sidewall 514 toward the second sidewall 515, one side of the magnet 520 being fixedly connected to the first sidewall 514, the bottom surface of the magnet 520 being fixedly connected to the stepped surface 513, and the magnetic gap 510 including the space between the magnet 520 and the second sidewall 515.

[0048] The first sidewall 514 and the second sidewall 515 of the first mounting groove 511 extend downward from the first surface 51a. The first mounting groove 511 also includes a third sidewall 516 opposite to the second sidewall 515, the third sidewall 516 being located around the second sidewall 515 and below the first sidewall 514. A stepped surface 513 connects the first sidewall 514 and the third sidewall 516, and there is a gap between the stepped surface 513 and the second sidewall 515. The magnetic gap 510 also includes the gap between the third sidewall 516 and the first sidewall 514, the distance between the first sidewall 514 and the second sidewall 515 is greater than the distance between the third sidewall 516 and the second sidewall 515, and the height of the first sidewall 514 is greater than or equal to the height of the magnetic sheet 520, so that the magnetic sheet 520 of the first annular magnet 521 does not protrude from the upper surface of the magnetic conductor 51, that is, the magnetic sheet 520 of the first annular magnet 521 is entirely embedded in the magnetic conductor 51.

[0049] The first sidewall 514 and the second sidewall 515 of the second mounting groove 512 extend upward from the second surface 51b. The second mounting groove 512 also includes a third sidewall 516 opposite to the second sidewall 515, the third sidewall 516 being located around the second sidewall 515 and above the first sidewall 514. A stepped surface 513 connects the first sidewall 514 and the third sidewall 516, and there is a gap between the stepped surface 513 and the second sidewall 515. The magnetic gap 510 also includes the gap between the third sidewall 516 and the first sidewall 514, the distance between the first sidewall 514 and the second sidewall 515 is greater than the distance between the third sidewall 516 and the second sidewall 515, and the height of the first sidewall 514 is greater than or equal to the height of the magnetic sheet 520, so that the magnetic sheet 520 of the second annular magnet 522 does not protrude from the lower surface of the magnetic conductor 51, that is, the magnetic sheet 520 of the second annular magnet 522 is entirely embedded in the magnetic conductor 51.

[0050] The first mounting groove 511 and the second mounting groove 512 are concentric rings projected onto the first surface 51a or the second surface 51b, and the distance between them is greater than zero. Further, the first mounting groove 511 and the second mounting groove 512 are both annular projected onto the first surface 51a or the second surface 51b. The outer diameter of the first annular magnet 521 is larger than the inner diameter of the second annular magnet 522. The depth of the first mounting groove 511 or the second mounting groove 512 is greater than half the distance between the first surface 51a and the second surface 51b, and portions of the first mounting groove 511 and the second mounting groove 512 overlap in the height / depth direction. The ratio of the thickness of the magnet sheet 520 to the outer diameter of the first annular magnet 521 or the second annular magnet 522 is 1:(4-50), preferably 1:(10-30).

[0051] The magnetic conductor 51 is integrally formed from a block of iron, for example, by punching a mounting groove into a single block of iron. The magnetic sheet 520 is made of rare-earth permanent magnet material. The magnetic sheet 520 is bonded to the magnetic conductor 51 with adhesive, and furthermore, adjacent magnetic sheets 520 are also bonded to each other with adhesive. There is a very small gap between adjacent magnetic sheets 520, the width of which is much smaller than the outer diameter of the toroidal magnet, for example, less than 1 / 100 of the outer diameter of the toroidal magnet.

[0052] Example 2 – Vehicle Speaker

[0053] Figures 3 to 9 This embodiment illustrates a vehicle speaker, such as a car door panel speaker, which is installed on the car door panel and radiates low-frequency sound into the passenger compartment.

[0054] Reference Figures 3 to 9As shown, the loudspeaker is specifically a dual-diaphragm loudspeaker, comprising a bracket 1 open at both ends, a first diaphragm 21 disposed on the first end of the bracket 1, a first voice coil 31 connected to the first diaphragm 21, a second diaphragm 22 disposed on the second end of the bracket 1, a second voice coil 32 connected to the second diaphragm 22, a first spring coil 41 fitted onto the first voice coil 31, and a second spring coil 42 fitted onto the second voice coil 32. The dual-diaphragm loudspeaker also includes a single magnetic circuit unit 5, disposed between the first diaphragm 21 and the second diaphragm 22. This single magnetic circuit unit is the magnetic circuit unit 5 of Embodiment 1, combined with... Figure 1 and Figure 2 As shown, the first surface 51a of the magnetic conductor 51 faces the first diaphragm 21, and the second surface 51b faces the second diaphragm 22. A magnetic gap 510 is formed between the first annular magnet 521 and the inner surface of the magnetic conductor 51 for the insertion of the first voice coil 31; a magnetic gap 510 is formed between the second annular magnet 522 and the inner surface of the magnetic conductor 51 for the insertion of the second voice coil 32.

[0055] The bracket 1 can be a one-piece component injection molded from plastic. The bracket 1 includes a cylindrical body 11, with a first diaphragm 21 and a second diaphragm 22 respectively suspended at opposite ends of the cylindrical body 11. The speaker is mounted and fixed to the vehicle via the cylindrical body 11, which may have mounting holes or other mounting structures. The cylindrical body 11 also has a wiring port, which includes a solder tab. The leads of the first voice coil 31 and the second voice coil 32 are connected to this solder tab to facilitate connection to a power amplifier and other components for receiving audio electrical signals.

[0056] The bracket 1 also includes a fixing ring 12 disposed within the cylinder 11, and a magnetic conductive element 51 is fixed to the fixing ring 12. The fixing ring 12 is bent multiple times to have multiple staggered annular mounting surfaces. The first surface 51a or the second surface 51b of the magnetic conductive element 51 is fixed to the first mounting surface. The outer edge of the first spring 41 is fixed to the second mounting surface, and the outer edge of the second spring 42 is fixed to the third mounting surface. The second and third mounting surfaces have opposite orientations, while the first mounting surface has the same orientation as the second or third mounting surface. For example, specifically to the attached... Figure 7 and 8 In the example, the first and second mounting surfaces face the first diaphragm 21, i.e., upwards; the third mounting surface faces the second diaphragm 22, i.e., downwards.

[0057] The cylinder 11 has multiple through holes 111, the first voice coil 31 has multiple through holes, the second voice coil 32 has multiple through holes, and the fixing ring 12 has multiple through holes to connect the various cavities inside the dual-diaphragm loudspeaker with the outside world, so as to facilitate heat dissipation.

[0058] The loudspeaker also includes a dust cap 6. The upper end of the first voice coil 31 is sealed by a dust cap 6, which is connected to the first diaphragm 21. The lower end of the second voice coil 32 is sealed by another dust cap 6, which is connected to the second diaphragm 22.

[0059] It should also be noted that the first diaphragm 21 has a truncated cone shape, and the second diaphragm 22 also has a truncated cone shape. The internal components of the loudspeaker are all housed inside the housing 11 and do not protrude outside the housing 11, thus being well protected by the housing 11.

[0060] Comparison – Speaker

[0061] A comparative example provides a dual-diaphragm loudspeaker similar to Embodiment 2, the only difference being the different magnetic circuit unit used, otherwise basically the same as Embodiment 2.

[0062] Specifically, such as Figure 10 As shown, the first annular magnet 521' and the second annular magnet 522' of the magnetic circuit unit 5' are an integral structure, and both are directly inserted into the magnetic conductor 51'.

[0063] Performance testing

[0064] The distortion curves of the dual-diaphragm loudspeakers in Example 2 and the comparative example are as follows: Figure 11 As shown, it can be seen that the distortion of the speaker in Example 2 is lower than that of the speaker in the comparative example.

[0065] The reasons are analyzed as follows:

[0066] Figure 12a The magnetic field distribution of the magnetic circuit unit 5 used in Embodiments 1 and 2 is shown. Figure 12b The magnetic field distribution of the magnetic circuit unit 5' used in the comparative example is shown. A comparison reveals that the directions of the magnetic field lines and the magnetic field distributions are significantly different. The energy conversion of the magnetic circuit unit 5' in the comparative example is insufficient, even low, which may result in lower speaker sensitivity; the magnetic flux density distribution is uneven, leading to nonlinear distortion. The magnetic circuit unit 5 designs in Examples 1 and 2 effectively improve sensitivity and reduce distortion, while also effectively solving the voice coil heat dissipation problem.

[0067] The magnetic circuit unit 5 in this embodiment solves the problems of low energy conversion efficiency, low sensitivity, and uneven magnetic flux density distribution, significantly improving sensitivity and reducing distortion, while also effectively addressing voice coil heat dissipation. The dual magnetic circuit structure design utilizes the gap structure of the magnetic circuit, making rational use of the internal structure and effectively reducing the height of the entire magnetic circuit unit 5 and the speaker. The magnetic circuit unit 5 in this embodiment effectively reduces speaker distortion, provides more uniform magnetic flux density, and achieves higher energy conversion, thus improving speaker sensitivity. The speaker in this embodiment exhibits low distortion, high sensitivity, and good voice coil heat dissipation; it also reduces overall height, making it suitable for use as a vehicle speaker and minimizing space occupation within the vehicle.

[0068] As indicated in this specification and claims, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0069] It can be further understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar.

[0070] It is further understood that the terms "first," "second," etc., are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.

[0071] The above embodiments are only for illustrating the technical concept and features of this utility model, and are preferred embodiments. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly, and they cannot be used to limit the protection scope of this utility model.

Claims

1. A magnetic circuit unit of a speaker comprising a magnetic conductor, characterized by, The magnetic conducting member is provided with an installation slot, the magnetic circuit unit comprises a plurality of magnetic steel sheets, the plurality of magnetic steel sheets are arranged in the installation slot and are spliced into a closed annular magnetic steel, and a magnetic gap for inserting a voice coil of a loudspeaker is formed between the annular magnetic steel and a surface of the magnetic conducting member.

2. The magnetic circuit unit of the loudspeaker according to claim 1, characterized in that, One of the annular magnetic steels is formed by splicing 3 to 10 magnetic steel sheets.

3. The magnetic circuit unit of the loudspeaker according to claim 2, characterized in that, One of the annular magnetic steels is formed by splicing 4, 6 or 8 magnetic steel sheets.

4. The magnetic circuit unit of the loudspeaker according to any one of claims 1 to 3, characterized in that, Each of the magnetic steel sheets comprises opposite top and bottom surfaces and a plurality of side surfaces between the top and bottom surfaces, at least one of the side surfaces is fixedly connected to the magnetic conducting member, and the top and / or bottom surface is in the shape of a fan ring.

5. The magnetic circuit unit of the loudspeaker according to claim 4, characterized in that, The installation slot comprises a stepped surface, opposite first and second side walls, the first side wall is located at the periphery of the second side wall, the stepped surface extends laterally from the first side wall towards the second side wall, one side surface of the magnetic steel sheet is fixedly connected to the first side wall, the bottom surface of the magnetic steel sheet is fixedly connected to the stepped surface, and the magnetic gap comprises a space between the magnetic steel and the second side wall.

6. The magnetic circuit unit of the loudspeaker according to claim 5, characterized in that, The installation slot further comprises a third side wall opposite to the second side wall, the third side wall is located at the periphery of the second side wall, the stepped surface is connected between the first and third side walls, and the magnetic gap further comprises a space between the third and first side walls.

7. The magnetic circuit unit of the loudspeaker according to claim 6, characterized in that, The installation slot is annular in whole, the distance between the first and second side walls is greater than the distance between the third and second side walls, and the height of the first side wall is greater than or equal to the height of the magnetic steel sheet.

8. The magnetic circuit unit of the loudspeaker according to claim 1, characterized in that, The magnetic conducting member has opposite first and second surfaces, the installation slot comprises a first installation slot formed on the first surface and a second installation slot formed on the second surface, the normal projections of the first and second installation slots on the first or second surface are concentric annular and the distance between them is greater than zero, the depth of the first or second installation slot is greater than half the distance between the first and second surfaces, each of the first and second installation slots is provided with an annular magnetic steel formed by splicing a plurality of magnetic steel sheets, the outer diameter of one of the annular magnetic steels is smaller than the inner diameter of the other annular magnetic steel, and the ratio of the thickness of the magnetic steel sheet to the outer diameter of the annular magnetic steel is 1:(4-50).

9. The magnetic circuit unit of the loudspeaker according to claim 1, characterized in that, The magnetic conducting member is integrally formed from a ferrous block, the material of the magnetic steel sheet is a rare earth permanent magnetic material, the magnetic steel sheet is bonded to the magnetic conducting member, and / or the adjacent magnetic steel sheets are bonded to each other.

10. A vehicle-mounted speaker comprising a diaphragm and a voice coil connected to the diaphragm, characterized by, The vehicle-mounted loudspeaker further comprises the magnetic circuit unit of the loudspeaker according to any one of claims 1 to 9, and the voice coil is movably inserted into the magnetic gap of the magnetic circuit unit.

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