Loudspeaker and vehicle-mounted audio system

Abstract

The invention discloses a loudspeaker and a vehicle-mounted audio system. The loudspeaker comprises a voice coil and a magnetic circuit, the magnetic circuit comprises a magnet yoke, magnetic steel and a magnetic conductive plate, the magnetic conductive plate is laminated on the magnetic steel, and the magnetic circuit is provided with a magnetic gap for insertion of the voice coil; the magnetic conductive plate comprises a main body part and a protruding part, the main body part is provided with a first surface and a second surface which are opposite, the protruding part protrudes and extends from the first surface or the second surface along the vibration axis of the loudspeaker, the first surface is attached to the magnetic steel, the protruding part is provided with a side face opposite to the magnet yoke, and the side face is provided with a side face opposite to the magnet yoke. A portion of a boundary of the magnetic gap is defined by a side of the boss. According to the loudspeaker, the magnetic field utilization rate of a magnetic circuit is improved, the voice coil rubbing risk is reduced, and the uniformity of a magnetic gap is improved.

Description

Technical Field

[0001] This invention relates to a loudspeaker and an in-vehicle audio system. Background Technology

[0002] The magnetic circuit is a key elastic component of a loudspeaker. Its main function is to provide a magnetic field, driving the voice coil to vibrate linearly along its axis of vibration within the magnetic field. The magnetic circuit typically includes a yoke, a magnet, and a magnetic guide plate. The magnetic guide plate, also called the front plate or pole piece, is generally stacked on top of the magnet. The magnetic guide plate is primarily responsible for guiding and constraining the magnetic field, ensuring the voice coil operates efficiently and stably.

[0003] Traditionally, magnetic guide plates (front panels) in the industry mostly use soft magnetic materials with high permeability, such as low-carbon steel (low cost, mature technology), and iron-silicon-aluminum materials. Magnetic guide plates (front panels) are mostly circular (corresponding to circular speakers) or rectangular (corresponding to rectangular speakers), forming a closed magnetic circuit in conjunction with magnets (usually toroidal or cylindrical) and yokes (U-iron / T-iron). If the circular or rectangular magnetic guide plate is misaligned with the magnets, it may cause voice coil rubbing problems, resulting in insufficient uniformity of the magnetic field gap. The guiding effect of the magnetic guide plate on the magnetic field lines also plays an important role in the utilization rate of the magnetic field.

[0004] 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. Summary of the Invention

[0005] This invention provides a loudspeaker that improves the magnetic field utilization of the magnetic circuit, reduces the risk of voice coil rubbing, and improves the uniformity of the magnetic gap. This invention also provides a vehicle audio system incorporating this loudspeaker.

[0006] The present invention adopts the following technical solution: A loudspeaker includes a voice coil and a magnetic circuit, the magnetic circuit including a yoke, a magnet, and a magnetic guide plate, the magnetic guide plate being stacked on the magnet, and a magnetic gap in the magnetic circuit for the voice coil to be inserted; the magnetic guide plate includes a main body and a protrusion, the main body having opposite first and second surfaces, the protrusion extending protruding from the first or second surface along the vibration axis of the loudspeaker, the first surface and the magnet being in contact with each other, the protrusion having a side surface opposite to the yoke, and a portion of the boundary of the magnetic gap being defined by the side surface of the protrusion.

[0007] In some embodiments, the magnetic yoke comprises a U-shaped iron, and a portion of the inner boundary of the magnetic gap is defined by the outer surface of the protrusion. In other embodiments, a portion of the outer boundary of the magnetic gap is defined by the inner surface of the protrusion.

[0008] In some preferred embodiments, the protrusion includes a first flange that protrudes rearward from the first surface along the vibration axis, the first flange surrounding the magnet, and a positioning groove is formed between the annular inner side of the first flange and the first surface, a portion of the magnet being located in the positioning groove.

[0009] In some preferred embodiments, the protrusion includes a second flange extending forward from the second surface along the vibration axis.

[0010] In some preferred embodiments, the annular outer surface of the first flange is aligned with the outer surface of the main body, and the outer diameter of the first flange is equal to the diameter of the magnet; the annular outer surface of the second flange is aligned with the outer surface of the main body, and the outer diameter of the second flange is equal to the diameter of the magnet; the inner boundary of the magnetic gap is defined by the annular outer surface of the first flange, the outer surface of the main body, and the annular outer surface of the second flange.

[0011] In some preferred embodiments, the height of the first flange along the vibration axis is equal to the height of the second flange along the vibration axis.

[0012] In some preferred embodiments, the first flange has a thickness in a direction perpendicular to the vibration axis, and the second flange has a thickness in a direction perpendicular to the vibration axis, wherein the thickness of the first flange and the thickness of the second flange are the same.

[0013] In some preferred embodiments, the ratio of the thickness of the first flange to the diameter of the main body is (0.1~20):100. In some preferred embodiments, the ratio of the thickness of the second flange to the diameter of the main body is (0.1~20):100.

[0014] In some preferred embodiments, the ratio of the height of the first flange along the vibration axis to the height of the main body is (0.2~1):3. In some preferred embodiments, the ratio of the height of the second flange along the vibration axis to the height of the main body is (0.2~1):3.

[0015] In some preferred embodiments, the cross-section of the magnetic conductive plate along the vibration axis is an axisymmetric figure, and its axis of symmetry is perpendicular to the vibration axis.

[0016] In some preferred embodiments, the first surface and the second surface are perpendicular to the vibration axis, the main body is circular, the diameter of the magnet is smaller than the diameter of the main body, and the protrusion is an annular shape with uniform thickness and height.

[0017] In some preferred embodiments, the magnetic circuit is fixed to a support, a diaphragm is suspended on the support, one end of the voice coil is fixed to the diaphragm, and the other end of the voice coil can be movably inserted into the magnetic gap along the vibration axis.

[0018] In some preferred embodiments, the loudspeaker is a tweeter, midrange speaker, or woofer, and the diaphragm has a spherical dome that arches forward along the vibration axis or has a cone that is truncated into a cone shape.

[0019] The present invention also adopts the following technical solution: An in-vehicle audio system including the aforementioned speaker.

[0020] In some embodiments, the loudspeaker is a tweeter, and the diaphragm of the loudspeaker has a spherical top that arches forward along the vibration axis.

[0021] In some embodiments, the loudspeaker is a midrange loudspeaker, the diaphragm of the loudspeaker extends along a plane perpendicular to the vibration axis, or has a cone in the shape of a truncated cone.

[0022] In some embodiments, the loudspeaker is a woofer, and the diaphragm of the loudspeaker has a cone-shaped truncated cone. The present invention adopts the above solution, which has the following advantages compared with the prior art: The loudspeaker of the present invention has a magnetic circuit with a raised portion that protrudes along the vibration axis relative to the main body, which makes the magnetic field utilization rate higher and the magnetic field distribution more uniform, without occupying too much space. The structure of the magnetic guide plate design can ensure the support and positioning of the voice coil, avoiding problems such as rubbing or distortion caused by voice coil misalignment. At the same time, the design of the magnetic guide plate can protect the magnet. Attached Figure Description

[0023] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a perspective view of a loudspeaker according to Embodiment 1 of the present invention.

[0025] Figure 2 This is a top view of a loudspeaker according to Embodiment 1 of the present invention.

[0026] Figure 3 for Figure 2 Sectional view along the AA direction.

[0027] Figure 4 This is a perspective view of a magnetic conductive plate according to Embodiment 1 of the present invention.

[0028] Figure 5 for Figure 4 A cross-sectional view of the magnetic conductive plate.

[0029] Figure 6 This is a perspective view of a loudspeaker according to Embodiment 2 of the present invention.

[0030] Figure 7 This is a cross-sectional view of a loudspeaker according to Embodiment 2 of the present invention.

[0031] Figure 8 This is a perspective view of a loudspeaker according to Embodiment 3 of the present invention.

[0032] Figure 9 This is a top view of a loudspeaker according to Embodiment 3 of the present invention.

[0033] Figure 10 for Figure 9 A cross-sectional view along the CC direction.

[0034] Figure 11 This is a cross-sectional view of a scaled-up loudspeaker.

[0035] Figure 12 This is a magnetic flux density mode contour plot of the comparative sample.

[0036] Figure 13 The magnetic flux density mode cloud diagram is for sample 1 according to Example 1.

[0037] Figure 14 The magnetic flux density mode cloud diagram is for sample 2 according to Example 1.

[0038] Figure 15 The magnetic flux density mode cloud diagram is for sample 3 according to Example 1.

[0039] Figure 16 The graphs show the changes in vibration displacement and magnetic flux for Example 1 and the comparative example.

[0040] In the above attached figures, 1. Bracket; 2. Diaphragm; 21. Dome; 22. Cone; 23. Dust cap; 24. Tweeter cup; 3. Voice coil; 4. Magnetic circuit; 40. Magnetic gap; 41. Magnetic yoke; 42. Magnet; 43. Magnetic guide plate; 430. Main body; 431. First surface; 432. Second surface; 433. First flange; 434. Second flange; 5. Spiral wave; 6. Capacitors. Detailed Implementation

[0041] 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.

[0042] In this article, "front" and "rear" are defined with reference to the speaker's vibration axis. "Front" refers to the direction of sound wave radiation along the vibration axis, and "outer" refers to the opposite direction. The directional terms "up," "down," and "horizontal" are intended to help those skilled in the art understand the speaker's structure and are not used to limit the speaker's position in its intended use. For example, a speaker can be mounted on a horizontal, inclined, or vertical surface of a vehicle, with the diaphragm facing up, down, front, back, left, or right.

[0043] Figures 1 to 10 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.

[0044] Example 1 Figures 1 to 5 An embodiment of a speaker is shown, specifically a tweeter. This speaker is suitable for installation in a vehicle as part of an in-vehicle audio system.

[0045] This loudspeaker is a moving-coil loudspeaker, employing the traditional electroacoustic conversion principle. (See reference...) Figures 1 to 5 As shown, the loudspeaker mainly includes a bracket 1, a diaphragm 2, a voice coil 3, and a magnetic circuit 4. The diaphragm 2 is suspended from the open end of the bracket 1, and the voice coil 3 is connected to the diaphragm 2 and driven by the magnetic circuit 4. The magnetic circuit 4 provides a magnetic field. When an electrical signal is applied to the coil of the voice coil 3, under the action of electromagnetic induction, the voice coil 3 is driven to reciprocate along the vibration axis of the loudspeaker, causing the diaphragm 2 to vibrate reciprocally along the expected vibration axis, producing a piston-like motion pattern. In this embodiment, the vibration axis of the loudspeaker is basically coincident with the center line of the voice coil 3.

[0046] The bracket 1 is made of a material with good strength, such as plastic or metal. The bracket 1 is preferably a single, integral part, for example, injection molded from plastic. Referring to Figures 1 and 2, the bracket 1 has an open end for connecting the diaphragm 2, etc. The bracket 1 may be provided with solder tabs for connecting to the leads of the voice coil 3 to receive electrical signals as a sound source. A flexible, porous pad can be connected to the bracket 1. The bracket 1 is mounted on a vehicle, and the pad is located between the bracket 1 and the vehicle to reduce vibrations transmitted from the vehicle to the speaker.

[0047] The front of the diaphragm 2 faces forward, and the back of the diaphragm 2 faces backward. The voice coil 3 is connected to the back of the diaphragm 2, for example, by adhesive bonding. The diaphragm 2 has a dome 21 that arches forward along the vibration axis; the diaphragm 2 also includes a surround surrounding the dome 21, which is suspended from the open end of the support 1. The dome 21 can be made of paper, fabric, non-woven fabric, plastic sheet, etc., and has good rigidity. The surround is elastic, allowing the cone to vibrate back and forth along the vibration axis, producing a piston-like motion. The surround can be made of rubber or fabric or non-woven fabric composited with thermoplastic / thermosetting resin. The surround and the dome 21 can be integrated or separate; if the surround and the dome 21 are two independent components, they are glued together.

[0048] like Figure 3 As shown, the voice coil 3 is connected to the diaphragm 2, and one end of the voice coil 3 is inserted into the magnetic gap 40 of the magnetic circuit 4. Specifically, the lower end of the voice coil 3, with the coil wound around it, is inserted into the magnetic gap 40 of the magnetic circuit 4. The coil of the voice coil 3 is connected to an electrical signal through a pair of leads. The magnetic circuit 4 provides a magnetic field. When the coil is energized, under the action of electromagnetic induction, the voice coil 3 will move in one direction, which is the vibration axis of the loudspeaker, that is, the axial center line of the voice coil 3. The bracket 1 is provided with a wiring port, in which solder pads are embedded for connecting external cables. Audio signals can be connected to the leads of the voice coil 3 through external cables.

[0049] The magnetic circuit 4 includes a magnetic yoke 41, a magnet 42, and a magnetically conductive plate 43 stacked on the magnet 42. The yoke 41 can be made of a magnetically conductive material, selected from iron, cobalt, nickel, or one of these or their alloys, such as ferrosilicon, silicon steel, or soft magnetic ferrite. The magnet 42 is made of a permanent magnet. The magnetically conductive plate 43 can be made of the same material as the yoke 41, a magnetically conductive material selected from iron, cobalt, nickel, or one of these or their alloys. In this embodiment, the yoke 41 includes a U-shaped iron, with the magnet 42 and the magnetically conductive plate 43 fixed inside the U-shaped iron. A magnetic gap 40 is formed inside the U-shaped iron, located between the inner peripheral wall of the U-shaped iron and the outer peripheral surface of the magnet 42 / magnetically conductive plate 43. In another embodiment, the yoke 41 can be a T-shaped iron. In this embodiment, the magnetic gap 40 is formed between the inner peripheral wall of the U-shaped iron and the outer peripheral side surface of the magnetically conductive plate 43.

[0050] Combination Figure 4 and Figure 5 As shown, the magnetic guide plate 43 includes a main body 430 and a protrusion. The main body 430 has a first surface 431 and a second surface 432 that are opposite to each other. The protrusion extends from the first surface 431 or the second surface 432 along the vibration axis of the speaker. Figure 3As shown, the first surface 431 and the magnet 42 are in contact with each other, the protrusion has a side surface opposite to the magnetic yoke 41, and a portion of the boundary of the magnetic gap 40 is defined by the side surface of the protrusion. In this embodiment, a portion of the inner boundary of the magnetic gap 40 is defined by the outer side surface of the protrusion.

[0051] The protrusion includes a first flange 433 that protrudes rearward from the first surface 431 along the vibration axis, and the first flange 433 surrounds the magnet 42. A positioning groove is formed between the annular inner side of the first flange 433 and the first surface 431, and a portion of the magnet 42 is located in the positioning groove. This positioning groove serves a positioning function. During assembly, adhesive is applied to the first surface 431 of the main body 430 or to the magnet 42, and then the magnet 42 is placed in the positioning groove. This reduces the risk of misalignment between the magnetic guide plate 43 and the magnet 42, ensures uniform magnetic gap 40, and thus avoids the problem of voice coil rubbing.

[0052] The protrusion includes a second flange 434 extending forward from the second surface 432 along the vibration axis. The annular outer surface of the first flange 433 is aligned with the outer surface of the main body 430, and the outer diameter of the first flange 433 is equal to the diameter of the magnet 42; the annular outer surface of the second flange 434 is aligned with the outer surface of the main body 430, and the outer diameter of the second flange 434 is equal to the diameter of the magnet 42; the inner boundary of the magnetic gap 40 is defined by the annular outer surface of the first flange 433, the outer surface of the main body 430, and the annular outer surface of the second flange 434. In this embodiment, the entire inner boundary of the magnetic gap 40 is defined by the magnetic guide plate 43, and the outer boundary of the magnetic gap 40 is defined by the magnetic yoke 41. In some other embodiments, the inner boundary of the magnetic gap 40 is defined by the magnet 42 and the magnetic guide plate 43.

[0053] The height of the first flange 433 along the vibration axis is equal to the height of the second flange 434 along the vibration axis. The ratio of the height of the first flange 433 along the vibration axis to the height of the main body 430 is (0.2~1):3, preferably (0.5~0.8):3. The ratio of the height of the second flange 434 along the vibration axis to the height of the main body 430 is (0.2~1):3, preferably (0.5~0.8):3.

[0054] The first flange 433 has a thickness in a direction perpendicular to the vibration axis, and the thickness is half the difference between the outer diameter and the inner diameter of the first flange 433. The second flange 434 has a thickness in a direction perpendicular to the vibration axis, and the thickness is half the difference between the outer diameter and the inner diameter of the first flange 433. The thickness of the first flange 433 and the thickness of the second flange 434 are the same. The ratio of the thickness of the first flange 433 to the diameter of the main body 430 is (0.1~20):100, preferably (1~10):100. The ratio of the thickness of the second flange 434 to the diameter of the main body 430 is (0.1~20):100, preferably (1~10):100.

[0055] like Figure 5 As shown, the cross-section of the magnetic plate 43 along the vibration axis is an axisymmetric figure, with its axis of symmetry perpendicular to the vibration axis. The first surface 431 and the second surface 432 are perpendicular to the vibration axis. The main body 430 is circular, and the diameter of the magnet 42 is smaller than the diameter of the main body 430. The protrusion is a ring with uniform thickness and uniform height.

[0056] The embodiment also provides an in-vehicle audio system including the speaker described above. The speaker is a tweeter responsible for reproducing high-frequency sounds.

[0057] Example 2 Figure 6 and Figure 7 This embodiment illustrates a loudspeaker, which is a midrange loudspeaker and can be used in a vehicle audio system to reproduce midrange frequencies. The magnetic plate 43 and magnet 42 in this embodiment have the same structure as in Embodiment 1, but are larger in size.

[0058] Reference Figure 6 and Figure 7 As shown, the diaphragm 2 of this midrange loudspeaker has a cone 22 in the shape of a truncated cone. The outer edge of the cone 22 is suspended from the bracket 1 by a surrounding member; a central hole is formed at the tip of the cone 22, through which the voice coil 3 passes. A dust cap 23 is connected to the cone 22, covering the front of the voice coil 3. A through hole is formed on the voice coil 3 to connect the inner and outer cavities of the voice coil 3. The loudspeaker also includes a spider 5, which is connected to the diaphragm 2 and / or the voice coil 3 to suppress the diaphragm 2 and / or the voice coil 3 from moving in directions other than intended. Specifically, the spider 5 is fitted onto the voice coil 3, the inner edge of the spider 5 is fixedly connected to the outer surface of the voice coil 3, and the outer edge of the spider 5 is directly fixedly connected to the outer surface of the voice coil 3.

[0059] The support 1 has a hollow cylindrical body that is open at both ends, and the cylindrical body encloses the diaphragm 2, voice coil 3, and all or part of the magnetic circuit 4 inside. A capacitor 6 is fixed inside the support 1, and the capacitor 6 and the coil of the voice coil 3 are connected in series.

[0060] In this embodiment, the inner boundary of the magnetic gap 40 is jointly defined by the outer side of the magnetic guide plate 43 and a portion of the outer side of the magnet 42, and the outer boundary of the magnetic gap 40 is defined by the inner surface of the magnetic yoke 41. The magnetic yoke 41 itself also has an annular groove, which is located below the component 40 and is interconnected.

[0061] Example 3 Figures 7 to 10 This embodiment illustrates a loudspeaker, which is a woofer and can be used in a vehicle audio system to reproduce low-frequency sounds. The magnetic plate 43 and magnet 42 in this embodiment have the same structure as in Embodiment 1, but are larger in size.

[0062] Reference Figures 7 to 10 As shown, the midrange loudspeaker has a cone 22 in the shape of a truncated cone. The outer edge of the cone 22 is suspended from the bracket 1 by a surrounding member; a central hole is formed at the tip of the cone 22, through which the voice coil 3 passes. A dust cap 23 is connected to the cone 22, covering the front of the voice coil 3. A through hole is formed on the voice coil 3 to connect the inner and outer cavities of the voice coil 3. The loudspeaker also includes a spider 5, which is connected to the diaphragm 2 and / or the voice coil 3 to suppress the diaphragm 2 and / or the voice coil 3 from moving in directions other than intended. Specifically, the spider 5 is fitted onto the voice coil 3, with its inner edge fixedly connected to the outer surface of the voice coil 3, and its outer edge directly fixedly connected to the outer surface of the voice coil 3. The bracket 1 has a hollow cylindrical body open at both ends, which encloses the diaphragm 2, the voice coil 3, and all or part of the magnetic circuit 4 inside. A tweeter 24 is also provided in front of the voice coil 3 for enhancing the sound in the high-frequency range. The tweeter 24 is a hollow, horn-shaped structure with openings at both ends. The smaller end is connected to the front end of the voice coil 3, and the larger end extends forward.

[0063] In this embodiment, the inner boundary of the magnetic gap 40 is jointly defined by the outer side of the magnetic guide plate 43 and a portion of the outer side of the magnet 42, and the outer boundary of the magnetic gap 40 is defined by the inner surface of the magnetic yoke 41. The magnetic yoke 41 itself also has an annular groove, which is located below the component 40 and is interconnected.

[0064] Comparative Example Reference Figure 11 The comparative speaker differs from Embodiment 1 only in the structure of the magnetic guide plate 43'; otherwise, they are essentially the same. Specifically, the comparative magnetic guide plate 43' is entirely circular and does not have any protrusions. The thickness of the magnetic guide plate 43' is equal to the thickness of the main body 430 of the magnetic guide plate 43 in Embodiment 1.

[0065] Simulation test: The comparative loudspeaker sample and the three samples according to Example 1 were subjected to reverse testing, and the results are as follows: Figure 12A magnetic flux density mode cloud diagram of a comparative sample is shown, wherein the thickness of the magnetic plate 43' in the comparative sample is equal to the thickness of the main body 430 of the magnetic plate 43 in the three samples according to Example 1. Figure 13 The magnetic flux density mode cloud diagram of sample 1 according to Example 1 is shown, wherein the thickness of the first flange 433 and the second flange 434 is 0.5 mm. Figure 14 The magnetic flux density mode cloud diagram of sample 2 according to Example 1 is shown, wherein the thickness of the first flange 433 and the second flange 434 is 0.8 mm. Figure 15 A magnetic flux density mode cloud diagram of sample 2 according to Example 1 is shown, wherein the thickness of the first flange 433 and the second flange 434 is 1 mm.

[0066] Combination Figures 12 to 15 A comparison of the region of the magnetic plate 43 near the magnetic gap 40 shows that the magnetic flux density of the "I"-shaped magnetic plate 43 in the embodiment is greater than that of the ordinary magnetic plate 43 in the comparative example. The structure of the magnetic plate 43 in the embodiment can make fuller use of the magnetic field and improve the magnetic field utilization rate. From Figure 13 and Figure 14 It can be seen that when the flange height increases, the magnetic field uniformity near the magnetic gap 40 will be affected. The inventors found that controlling the height of the first flange 433, the second flange 434 and the main body 430 to (0.5~0.8):3 has a better effect.

[0067] Figure 16 The curves showing the variation of vibration displacement with magnetic flux for Example 1 and the comparative example are shown. Figure 16 As can be seen, the trend of the change curve of vibration displacement and magnetic flux in the embodiment is lower than that in the comparison, which also indicates that the voice coil 3 moves to cut magnetic lines of force in the magnetic gap 40, and its magnetic field distribution is more uniform.

[0068] The embodiment optimizes the design of the magnetic circuit 4 to ensure that the magnetic field acts efficiently on the voice coil 3. Among them, (1) the magnetic circuit 4 of the loudspeaker is composed of a magnet 42, a magnetic guide plate 43, and a magnetic yoke 41. The magnetic field generated by the magnetic circuit 4 will spread to the surroundings (magnetic leakage), while the function of the magnetic guide plate 43 is to concentrate and guide the magnetic field lines of the magnet to the gap between the magnetic guide plate 43 and the magnetic yoke 41 (i.e., the core area of ​​the vibration of the voice coil 3). The three work together to form a closed magnetic circuit 4, which greatly reduces magnetic field leakage and improves magnetic field utilization. Otherwise, most of the magnetic field would be wasted in the air. (2) Forming a uniform magnetic field gap: The magnetic guide plate 43 and the other precise fit (parallelism, spacing control) can generate a uniform and stable magnetic field in the magnetic gap 40. After the voice coil 3 is energized, its wires cut the magnetic field lines to generate an Ampere force (F=BIL). The uniform magnetic field can ensure that the voice coil 3 is subjected to linear force, reduce nonlinear distortion, and improve the accuracy of sound reproduction. (3) Support and positioning of voice coil 3: The magnetic plate 43 provides radial positioning for the voice coil 3 (limiting the left and right offset of the voice coil 3), generating a uniform magnetic gap 40. Together with the axial support of the spring 5, it ensures that the voice coil 3 only moves in the vertical direction (vibration direction), avoiding rubbing (friction with the magnet) or distortion caused by offset.

[0069] The magnetic guide plate 43, through efficient magnetic conduction, closed magnetic circuit 4, and optimized magnetic field uniformity, directly affects the speaker's sensitivity, distortion, and reliability (positioning and heat dissipation design). The I-shaped magnetic guide plate 43 design results in higher magnetic field utilization and more uniform magnetic field distribution without occupying too much space. The structure of this magnetic guide plate 43 design ensures support and positioning of the voice coil 3, avoiding problems such as rubbing or distortion caused by voice coil 3 misalignment. At the same time, the I-shaped magnetic guide plate 43 design protects the magnet 42 and helps optimize heat dissipation in the magnetic circuit 4 system. As a rigid structural component, it also prevents the magnet 42 from being deformed by external forces.

[0070] 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.

[0071] It can be further understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar.

[0072] 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.

[0073] The above embodiments are only for illustrating the technical concept and features of the present invention, and are preferred embodiments. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention.

Claims

1. A loudspeaker, comprising a voice coil and a magnetic circuit, the magnetic circuit comprising a magnetic yoke, a magnet, and a magnetic guide plate, the magnetic guide plate being stacked on the magnet, and the magnetic circuit having a magnetic gap for the voice coil to be inserted; characterized in that, The magnetic guide plate includes a main body and a protrusion. The main body has a first surface and a second surface that are opposite to each other. The protrusion extends from the first surface or the second surface along the vibration axis of the speaker. The first surface and the magnet are in contact with each other. The protrusion has a side surface that is opposite to the magnetic yoke. A portion of the boundary of the magnetic gap is defined by the side surface of the protrusion.

2. The loudspeaker according to claim 1, characterized in that, The protrusion includes a first flange that protrudes rearward from the first surface along the vibration axis. The first flange surrounds the magnet, and a positioning groove is formed between the annular inner side of the first flange and the first surface. A portion of the magnet is located in the positioning groove.

3. The loudspeaker according to claim 2, characterized in that, The protrusion includes a second flange extending forward from the second surface along the vibration axis.

4. The loudspeaker according to claim 3, characterized in that, The annular outer surface of the first flange is aligned with the outer surface of the main body, and the outer diameter of the first flange is equal to the diameter of the magnet; the annular outer surface of the second flange is aligned with the outer surface of the main body, and the outer diameter of the second flange is equal to the diameter of the magnet; the inner boundary of the magnetic gap is defined by the annular outer surface of the first flange, the outer surface of the main body, and the annular outer surface of the second flange.

5. The loudspeaker according to claim 3, characterized in that, The height of the first flange along the vibration axis is equal to the height of the second flange along the vibration axis.

6. The loudspeaker according to claim 3, characterized in that, The first flange has a thickness in a direction perpendicular to the vibration axis, and the second flange has a thickness in a direction perpendicular to the vibration axis, wherein the thickness of the first flange and the thickness of the second flange are the same. The ratio of the thickness of the first flange to the diameter of the main body is (0.1~20):100; the ratio of the thickness of the second flange to the diameter of the main body is (0.1~20):

100.

7. The loudspeaker according to any one of claims 3 to 6, characterized in that, The ratio of the height of the first flange along the vibration axis to the height of the main body is (0.2~1):3; the ratio of the height of the second flange along the vibration axis to the height of the main body is (0.2~1):

3.

8. The loudspeaker according to any one of claims 3 to 6, characterized in that, The cross-section of the magnetic conductive plate along the vibration axis is an axisymmetric figure, and its axis of symmetry is perpendicular to the vibration axis.

9. The loudspeaker according to claim 1, characterized in that, The first surface and the second surface are perpendicular to the vibration axis; the main body is circular; the diameter of the magnet is smaller than the diameter of the main body; the protrusion is an annular shape with uniform thickness and height. The magnetic circuit is fixed on the bracket, a diaphragm is suspended on the bracket, one end of the voice coil is fixed to the diaphragm, and the other end of the voice coil can be movably inserted into the magnetic gap along the vibration axis; The loudspeaker is a tweeter, midrange speaker, or woofer, and the diaphragm has a spherical dome that arches forward along the vibration axis or has a cone that is truncated into a cone shape.

10. A vehicle-mounted audio system, characterized in that, Includes the loudspeaker as described in any one of claims 1 to 9.

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