A precise structure positioning strong magnetic array for annular planar coil horn

Abstract

The utility model relates to the technical field of electroacoustics, concretely is a kind of precision structure positioning strong magnetic array for annular planar coil loudspeaker, including the backplate made of one metal sheet, one side of backplate is defined as working surface, and working surface has the air gap of openwork, further including the magnet array fixed on working surface, the magnet array includes a circular magnet and multiple annular magnets concentric with the circular magnet, and the circular magnet and the annular magnet are spaced apart;Multiple positioning lugs are integrally formed on the working surface of backplate by insert injection molding, and circular magnet and annular magnet are respectively clamped and fixed in the form of at least two positioning lugs cooperating into group. When the circular magnet and the annular magnet in the magnet array are clamped and fixed by positioning lug, it can be clamped in place in one step, without additional dispensing, while reducing the assembly difficulty of magnet array and overall thickness, it can also better prevent the loosening displacement of magnet array when subjected to impact and vibration.

Description

Technical Field

[0001] This utility model relates to the field of electroacoustic technology, specifically a precision structure positioning strong magnetic array for a ring-shaped planar coil loudspeaker, and a magnetic circuit system for a planar diaphragm loudspeaker. Background Technology

[0002] A planar diaphragm loudspeaker, also known as a flat-panel speaker, is an audio device that uses a planar diaphragm structure. Its core feature is the use of a planar diaphragm. A coil similar to the conductive layer of a printed circuit board is formed on the surface of the planar diaphragm. Magnet arrays are arranged on both sides of the planar diaphragm to form a uniform vertical magnetic field. When an alternating current passes through the coil of the planar diaphragm, the coil is excited by the Lorentz force in the magnetic field, thereby driving the planar diaphragm to vibrate and produce sound.

[0003] In existing technologies, the magnet arrays of planar diaphragm loudspeakers are mostly made by injection molding permanent magnets as in-mold inserts onto the array support. Due to the limited space in the injection mold cavity, the precise distribution of permanent magnets within the mold is technically challenging, and maintaining the positioning accuracy of the permanent magnets under the impact of the injection fluid also presents significant technical difficulties. Furthermore, since the array support needs to cover the bottom and sides of the permanent magnets, the material thickness of the array support itself is difficult to reduce to below 1.8mm. When magnet arrays are arranged on both sides of the planar diaphragm, the magnet array device alone will occupy at least 3.6mm of thickness, limiting the overall thinness and lightness of the planar diaphragm loudspeaker.

[0004] Regarding the above issues, the applicant previously filed a Chinese utility model application with application number 2025216325365, providing a high-polymer ultrathin magnet array device for a planar diaphragm loudspeaker as a solution.

[0005] In subsequent practice, the applicant discovered that the aforementioned application used clips to pre-assemble the permanent magnets in the magnet array onto the back plate, and then fixed them with adhesive. However, the clips are made of thin metal sheets and the back plate is stamped as a single piece, resulting in limited structural strength of the clips themselves, which is insufficient to overcome the impact of the repulsive force between the permanent magnets on the assembly reliability. When the finished planar diaphragm loudspeaker is subjected to impacts and vibrations during use, the adhesive fixing of the permanent magnets may still fail, and the magnets may easily loosen and displace from the clips, leading to abnormal magnetic field of the planar diaphragm.

[0006] Therefore, it is necessary to propose further iterative technologies for the magnet array device of planar diaphragm loudspeakers, which can reduce the assembly difficulty and overall thickness of the magnet array while strengthening the fixing effect of the magnet array on the permanent magnet. Utility Model Content

[0007] In response to the aforementioned needs of the prior art, this utility model provides a precision structure positioning strong magnetic array for a ring-shaped planar coil horn, the technical solution of which is as follows.

[0008] A precision-structured positioning magnetic array for a ring-shaped planar coil horn includes a backplate made of a thin metal sheet, one side of which is defined as a working surface with a perforated air gap. The backplate also includes a magnet array fixed to the working surface, comprising a circular magnet and multiple ring magnets concentrically aligned with the circular magnet, spaced apart from each other. Multiple positioning protrusions are integrally molded onto the working surface of the backplate using insert injection molding, with at least two positioning protrusions used in groups to clamp and fix the circular magnet and the ring magnets respectively.

[0009] On one hand, the positioning protrusions used to clamp and fix the circular magnets engage with each other on opposite sides, and are used to clamp the circular surface of the clamped circular magnets toward the central axis.

[0010] On the other hand, the positioning protrusions for clamping and fixing the ring magnet engage with each other on opposite sides to clamp the outer ring surface of the clamped ring magnet toward the central axis; or, the positioning protrusions for clamping and fixing the ring magnet engage with each other on opposite sides to support the inner ring surface of the clamped ring magnet away from the central axis.

[0011] In an improved design, the back plate has through holes corresponding to the positioning protrusions, and the other side of the back plate opposite the working surface has a base integrally formed with the positioning protrusions through the through holes.

[0012] In another improved design, the end of the positioning bump furthest from the working surface is lower than or flush with the circular or annular magnet.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) Multiple positioning protrusions are integrally formed on the working surface of the back plate by insert injection molding. The positioning protrusions have extremely high molding accuracy and stronger structural strength. When the circular magnets and ring magnets in the magnet array are clamped and fixed by the positioning protrusions, they can be clamped in one step without additional glue application. This reduces the assembly difficulty and overall thickness of the magnet array, and also better prevents the magnet array from loosening and shifting when subjected to collisions and vibrations.

[0015] (2) The back plate combined with the magnet array forms a single-sided magnetic structure, which significantly enhances the magnetic line density of the working surface. Compared with the prior art, the driving force of the planar diaphragm is significantly improved when using the same magnet array.

[0016] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is an exploded view of the structure of this utility model.

[0019] Figure 3 This is a schematic diagram of the clamping of the circular magnet in this utility model.

[0020] Figure 4 This is a schematic diagram of one type of clamping of the ring magnet in this utility model.

[0021] Figure 5 This is another schematic diagram of the mounting of the ring magnet in this utility model.

[0022] Figure 6 This is a schematic diagram of the molding structure of the positioning protrusion and the back plate in this utility model.

[0023] Figure 7 This is a structural schematic diagram of the first embodiment of the present utility model.

[0024] Figure 8 This is a structural schematic diagram of the second embodiment of the present invention.

[0025] Figure 9 This is a structural schematic diagram of the third embodiment of the present invention.

[0026] Figure 10 This is a structural schematic diagram of the fourth embodiment of this utility model.

[0027] Explanation of reference numerals in the attached figures:

[0028] Backplate 1, working surface 11, air gap 12, positioning bump 2, magnet array 3, circular magnet 31, ring magnet 32, positioning bump 2a, positioning bump 2b, ring magnet 32a, ring magnet 32b, through hole 13, base 21, inspection port 14. Detailed Implementation

[0029] Please see Figures 1 to 2 In one embodiment, the present invention provides a precision structure positioning strong magnetic array for a ring-shaped planar coil horn. A back plate 1 is made of a thin metal sheet, one side of which is defined as a working surface 11. The working surface 11 has a hollowed-out air gap 12. Multiple positioning protrusions 2 are integrally formed on the working surface 11 of the back plate 1 by injection molding. A magnet array 3 is also fixedly arranged on the working surface 11. The magnet array 3 includes a circular magnet 31 and multiple ring magnets 32 concentrically aligned with the circular magnet 31. The circular magnet 31 and the ring magnets 32 are spaced apart. The circular magnet 31 and the ring magnets 32 are clamped and fixed in groups of at least two positioning protrusions 2.

[0030] In the above embodiment, because the backplate 1 is made of a thin metal sheet, and the backplate 1 combined with the magnet array 3 forms a single-sided magnetic structure, the magnetic linear density of the working surface 11 is significantly enhanced. Compared with the prior art, when using the same permanent magnets, the driving force for the planar diaphragm is significantly improved. In a random measurement, other types of magnet arrays had a peak magnetic field strength of 1868 Gs on the working surface, while the above embodiment achieved a peak magnetic field strength of 2188 Gs on the working surface 11. After multiple sets of tests, the results show that this invention can increase the magnetic field strength of the working surface 11 by 17%-20%.

[0031] Preferably, the back panel 1 is made of cast iron sheet, galvanized iron sheet or stainless steel sheet by stamping.

[0032] In the above embodiments, the positioning protrusions 2 can be in groups of two, three, or more, and the grouped positioning protrusions 2 are equidistantly distributed on the circumference. Obviously, the equidistant distribution of the grouped positioning protrusions 2 on the circumference is more conducive to maintaining the stability of the central axis for the fixed circular magnet 31 or annular magnet 32.

[0033] Meanwhile, in the above embodiment, multiple positioning protrusions 2 are integrally formed on the working surface 11 of the back plate 1 by insert injection molding. The positioning protrusions 2 have extremely high molding precision and stronger structural strength. When the circular magnets 31 and annular magnets 32 in the magnet array 3 are clamped and fixed by the positioning protrusions 2, they can be clamped in one step without additional glue application. This reduces the assembly difficulty and overall thickness of the magnet array, and also better prevents the magnet array from loosening and shifting when subjected to collisions and vibrations.

[0034] like Figure 3 As shown, in a preferred embodiment, the positioning protrusions 2 for clamping and fixing the circular magnet 31 engage with each other on opposite sides, and are used to clamp the circular surface of the clamped circular magnet 31 toward the central axis. In this arrangement, the positioning protrusions 2 for clamping and fixing the circular magnet 31 provide a centripetal clamping force from the circular surface of the clamped circular magnet 31, and with the cooperation of multiple positioning protrusions 2 in the same group, a clamping and fixing effect is achieved to keep the central axis of the circular magnet 31 stable.

[0035] Furthermore, the positioning protrusions 2 used to clamp and fix the circular magnet 31 have arc surfaces on their opposite sides that mate with the circular surface of the clamped circular magnet 31, which increases the contact area and enhances the centripetal clamping effect.

[0036] like Figure 4As shown, in another preferred embodiment, the positioning protrusions 2a used to clamp and fix the annular magnet 32a engage with each other on opposite sides, clamping the outer ring surface of the clamped annular magnet 32a toward the central axis. This arrangement has a similar effect to the clamping of the circular magnet 31 described above. The positioning protrusions 2a used to clamp and fix the annular magnet 32a provide a centripetal clamping force from the outer ring surface of the clamped annular magnet 32a. With the cooperation of multiple positioning protrusions 2a in the same group, a clamping and fixing effect is achieved to maintain the stability of the central axis of the annular magnet 32a.

[0037] Furthermore, the positioning protrusions 2a used to clamp and fix the annular magnet 32a have arc surfaces on their opposite sides that mate with the outer ring surface of the clamped annular magnet 32a, which increases the contact area and enhances the centripetal clamping effect.

[0038] like Figure 5 As shown, in another preferred embodiment, the positioning protrusions 2b used to clamp and fix the annular magnet 32b engage with each other on opposite sides, supporting the inner ring surface of the clamped annular magnet 32b outwards from the central axis. In this arrangement, the positioning protrusions 2b used to clamp and fix the annular magnet 32b provide centrifugal outward support from the inner ring surface of the clamped annular magnet 32b. With the cooperation of multiple positioning protrusions 2b in the same group, the clamping and fixing effect of maintaining the central axis stability can also be achieved.

[0039] Furthermore, the positioning protrusions 2b used to clamp and fix the annular magnet 32b are opposite to each other and respectively form arc surfaces that mate with the inner ring surface of the clamped annular magnet 32b. Their positive effect is still to increase the contact area on the one hand and enhance the centripetal clamping effect on the other.

[0040] like Figure 6 As shown in the various embodiments described above, to further enhance the structural strength of the positioning protrusion 2, the following improvement scheme can also be adopted. Specifically, a through hole 13 corresponding to the positioning protrusion 2 is formed on the back plate 1, and the other side of the back plate 1 opposite to the working surface 11 has a base 21 integrally formed with the positioning protrusion 2 through the through hole 13. In this improvement scheme, the positioning protrusion 2, the base 21, and the back plate 1 are integrally combined, resulting in higher structural strength and making it less likely to separate and detach from the back plate 1. In addition, by setting the positioning protrusion 2 to extend beyond the outer edge of the through hole 13, the bonding strength between the positioning protrusion 2 and the back plate 1 will be further improved.

[0041] like Figure 7 As shown, in the first embodiment of this utility model, the end of the positioning protrusion 2 away from the working surface 11 is set to be lower than the circular magnet 31 and the ring magnet 32, which reduces the molding difficulty and saves raw materials.

[0042] like Figure 8As shown, in the second embodiment of this utility model, the end of the positioning protrusion 2 away from the working surface 11 is set to be flush with the circular magnet 31 and the annular magnet 32, which can achieve a better clamping and fixing effect.

[0043] Furthermore, to facilitate inspection of the accuracy of the magnet array's positioning, the air gap 12 on the working surface 11 is an arc-shaped opening distributed in the gap between the circular magnet 31 and the annular magnet 32, and the arc-shaped edges of the air gap 12 on opposite radial sides are aligned with the edges of the circular magnet 31 or the annular magnet 32 ​​on that side, respectively. When the central axes of the circular magnet 31 and the annular magnet 32 ​​are significantly offset, the edges of the circular magnet 31 and the annular magnet 32 ​​will be clearly exposed in the air gap 12, facilitating quality inspection.

[0044] Furthermore, based on the aforementioned setting regarding the accuracy of the positioning of the inspection magnet array, this invention provides inspection ports 14 along the radially opposite arcuate edges of the air gap 12. The shape of the inspection ports 14 is not limited to a specific shape; their purpose is to increase the inspection range of the edges of the circular magnet 31 and the annular magnet 32. For example... Figure 9 As shown, in the third embodiment of this utility model, the inspection port 14 is exemplaryly set as a semi-circular notch; as Figure 10 As shown, in the fourth embodiment of this utility model, the inspection port 14 is exemplaryly set as a triangular notch. Furthermore, the inspection port 14 can also be formed by radially widening the arcuate edge along the air gap 12.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A precision-structured positioning magnetic array for a ring-shaped planar coil horn, comprising a backplate made of a thin metal sheet, one side of which is defined as a working surface with a perforated air gap, and a magnet array fixed to the working surface, the magnet array comprising a circular magnet and a plurality of ring magnets concentrically aligned with the circular magnet, the circular magnet and the ring magnets being spaced apart; characterized in that, Multiple positioning protrusions are integrally molded onto the working surface of the back plate by insert injection molding, and circular magnets and ring magnets are respectively clamped and fixed by at least two positioning protrusions in a group.

2. The precision structure positioning magnetic array for a ring-shaped planar coil horn as described in claim 1, characterized in that, The positioning bumps that are matched in groups are evenly distributed in the circumferential direction.

3. The precision structure positioning magnetic array for a ring-shaped planar coil horn as described in claim 1, characterized in that, The positioning protrusions used to clamp and fix the circular magnet engage with each other on opposite sides, and are used to clamp the circular surface of the clamped circular magnet toward the central axis.

4. A precision structure positioning high magnetic array for a toroidal planar coil horn according to claim 3, wherein, The positioning protrusions used to clamp and fix the circular magnets each form an arc surface on one side facing each other, which mates with the circular surface of the clamped circular magnet.

5. A precision structure positioning magnetic array for a ring-shaped planar coil horn as described in claim 1, characterized in that, The positioning protrusions used to clamp and fix the ring magnet engage with each other on opposite sides to hold the outer ring surface of the clamped ring magnet toward the central axis.

6. A precision structure positioning high magnetic array for a toroidal planar coil horn according to claim 5, wherein, The positioning protrusions used to clamp and fix the ring magnets each form an arc surface on one side facing each other, which mates with the outer ring surface of the clamped ring magnet.

7. A precision structure positioning high magnetic array for toroidal planar coil horn according to claim 1, characterized in that, The positioning protrusions used to clamp and fix the ring magnet engage with each other on opposite sides, and are used to support the inner ring surface of the clamped ring magnet outward from the central axis.

8. A precision structure positioning high magnetic array for a toroidal planar coil horn according to claim 7, wherein, The positioning protrusions used to clamp and fix the ring magnet are on opposite sides and each forms an arc surface that mates with the inner ring surface of the clamped ring magnet.

9. A precision structure positioning magnetic array for a ring-shaped planar coil horn as described in any one of claims 1 to 8, characterized in that, The back plate has through holes corresponding to the positioning protrusions, and the other side of the back plate opposite the working surface has a base integrally formed with the positioning protrusions through the through holes.

10. A precision construction positioning high field array for a toroidal planar coil horn according to any one of claims 1 to 8, characterized in that The end of the positioning protrusion furthest from the working surface is lower than or flush with the round or ring magnet.

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