Sound generating device and terminal device

Abstract

The present invention discloses a sounding device and a terminal device. The sounding device includes a chassis, a magnetic circuit system and a vibration system. The magnetic circuit system includes a U-shaped iron, an inner magnetic circuit part and an outer magnetic circuit part. The inner magnetic circuit part is arranged in the accommodating groove of the U-shaped iron, and the outer magnetic circuit part is arranged on the supporting surface of the U-shaped iron and connected to the chassis. The outer magnetic circuit part and the U-shaped iron cooperate to cover the opening at one end of the accommodating cavity. A magnetic gap is formed by the side wall of the accommodating groove and the outer magnetic circuit part being spaced from the inner magnetic circuit part. A notch groove is provided on one side of the inner magnetic circuit part facing the magnetic gap. The vibration system includes a diaphragm and a voice coil connected to the diaphragm. The diaphragm is connected to the chassis and covers the opening at the other end of the accommodating cavity. One end of the voice coil away from the diaphragm is suspended in the magnetic gap. The purpose of the present invention is to provide a sounding device with good BL value and linear range. The sounding device can not only effectively reduce the weight, ensure good BL value and linear range, but also meet the design requirements of miniaturization and light weight.

Description

Technical Field

[0001] The present invention relates to the technical field of electroacoustic conversion, and particularly relates to a sound generating device and a terminal device applying the sound generating device. Background Art

[0002] A loudspeaker, also known as a speaker, is an electroacoustic transducer that converts electrical energy into sound energy through a certain physical effect. When different electrical energies are transmitted to the voice coil of the loudspeaker, the voice coil generates an energy that interacts with the magnetic field of the magnet. This interaction causes the diaphragm to vibrate. Since the electrical energy changes at any time, the voice coil of the loudspeaker moves forward or backward, and thus the diaphragm of the loudspeaker follows the movement. This action causes changes in the density of the air to generate sound.

[0003] In related technologies, the top plates of loudspeakers are mostly cylindrical or circular ring-shaped, and are bonded to the magnet with glue to form the magnetic circuit system of the loudspeaker together with the U-shaped iron or T-shaped iron. The top plate plays a role in guiding magnetism, and forms a magnetic circuit together with the U-shaped iron or T-shaped iron and the magnet, so that the energized voice coil makes a cutting magnetic induction line movement therein, driving the diaphragm to vibrate and generate sound. However, the magnetic permeability of some regions of the disc-shaped or circular ring-shaped top plate is very low. Retaining the regions with low magnetic permeability results in an increase in the weight of the top plate, which cannot meet the design requirements of miniaturization and light weight, and there are also problems with poor BL value and linear range. Summary of the Invention

[0004] The main object of the present invention is to provide a sound generating device and a terminal device, aiming to provide a sound generating device with good BL value and linear range. The sound generating device not only effectively reduces the weight, ensures good BL value and linear range, but also can meet the design requirements of miniaturization and light weight.

[0005] To achieve the above object, the present invention provides a sound generating device, and the sound generating device includes:

[0006] A chassis having a cavity with two open ends;

[0007] A magnetic circuit system including a U-shaped iron, an inner magnetic circuit part and an outer magnetic circuit part. The U-shaped iron has a receiving groove, the inner magnetic circuit part is disposed in the receiving groove, an end surface of the U-shaped iron adjacent to the notch of the receiving groove forms a supporting surface, the outer magnetic circuit part is disposed on the supporting surface and connected to the chassis. The outer magnetic circuit part and the U-shaped iron cooperate to cover an opening at one end of the cavity. A magnetic gap is formed by spacing between the side wall of the receiving groove and the outer magnetic circuit part and the inner magnetic circuit part. A notch groove is provided on a side of the inner magnetic circuit part facing the magnetic gap; and

[0008] A vibration system, the vibration system includes a diaphragm and a voice coil connected to the diaphragm, the diaphragm is connected to the chassis and covers the opening at the other end of the cavity, and one end of the voice coil away from the diaphragm is suspended in the magnetic gap.

[0009] In one embodiment, the inner magnetic circuit portion includes an inner magnet and an inner washer stacked, the inner magnet is clamped between the inner washer and the bottom wall of the accommodating groove, and a notch groove is provided on the side of the inner washer facing the magnetic gap;

[0010] The outer magnetic circuit portion includes an outer magnet and an outer washer stacked, the outer magnet is clamped between the outer washer and the supporting surface, and the outer washer is connected to the chassis.

[0011] In one embodiment, a concave groove is provided on the side of the inner washer facing away from the inner magnet.

[0012] In one embodiment, define the thickness of the inner magnet as h1 and the thickness of the outer magnet as h2, where 0.8 ≤ h1 / h2 ≤ 1.2;

[0013] And / or, define the maximum thickness of the inner washer as t1 and the thickness of the outer washer as t2, where 2 ≤ t1 / t2 ≤ 2.5;

[0014] And / or, define the radius of the inner washer as d1 and the width of the outer washer as d2, where 1.5 ≤ d1 / d2 ≤ 2;

[0015] And / or, the cross-section of the concave groove is semicircular, define the radius of the concave groove as R, define the maximum thickness of the inner washer as t1, and define the radius of the inner washer as d1, where t1 < R < d1.

[0016] In one embodiment, the notch groove extends along the circumference of the inner washer;

[0017] And / or, the notch groove is adjacent to the inner magnet;

[0018] And / or, a limiting protrusion protrudes from the side of the outer washer facing away from the magnetic gap, and a limiting groove is provided on the chassis, and the limiting protrusion is received and limited in the limiting groove.

[0019] In one embodiment, the inner magnetic circuit portion further includes a short-circuit ring, the short-circuit ring includes a first section and a second section arranged at an angle, the first section is connected to the side of the inner washer facing away from the inner magnet, and the second section is attached to the side of the inner washer facing the magnetic gap and extends to the inner magnet to cover the notch groove.

[0020] In one embodiment, the length of the notch groove along the axis of the magnetic gap is defined as a, and the length of the notch groove along a direction perpendicular to the axis of the magnetic gap is defined as b; wherein 1.8≤a / b≤2.2.

[0021] In one embodiment, a boss is protruding from the bottom wall of the accommodating groove, the boss is spaced apart from the side wall of the accommodating groove, and encloses a avoidance groove connected to the accommodating groove, the avoidance groove corresponds to the magnetic gap, and the inner magnetic circuit is partially supported by the boss;

[0022] And / or, a groove is formed on a side of the U iron facing away from the notch of the accommodating groove.

[0023] In one embodiment, the vibration system further comprises a centering ring, the inner side of which is connected to the outer wall of the voice coil, the basin frame is convexly provided with a fixing platform, and the outer side of the centering ring is connected to the fixing platform;

[0024] And / or, the U iron extends adjacent to the supporting surface toward a side away from the accommodating groove to form a supporting platform, the supporting platform is flush with the supporting surface, and the external magnetic circuit is partially supported by the supporting surface and the supporting platform.

[0025] The present invention further provides a terminal device, comprising a device housing and the above-mentioned sound-generating device, wherein the sound-generating device is arranged in the device housing.

[0026] The sound-generating device of the technical solution of the present invention is provided with a cavity with openings at both ends in a basin frame, so as to use the basin frame to install, fix and protect the magnetic circuit system and the vibration system. The magnetic circuit system is provided as a U-iron, an inner magnetic circuit part and an outer magnetic circuit part, and the inner magnetic circuit part is installed and fixed by using the containing groove of the U-iron, and the outer magnetic circuit part is provided on the supporting surface of the U-iron, so that the inner magnetic circuit part, the side wall of the containing groove of the U-iron and the outer magnetic circuit part are enclosed to form a magnetic gap for suspending the voice coil of the vibration system. When the voice coil is energized, the voice coil moves in the magnetic gap of the magnetic circuit system to cut the magnetic flux lines, thereby driving the diaphragm to vibrate and produce sound; a notch groove is provided on the side of the inner magnetic circuit part facing the magnetic gap, so as to eliminate the part of the inner magnetic circuit part with low magnetic permeability to reduce the weight of the inner magnetic circuit part, and make full use of the part of the inner magnetic circuit part with high magnetic permeability to ensure a good BL value and linear range of the sound-generating device, while meeting the design requirements of miniaturization and lightweight. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 Schematic cross-sectional view of the sound generating device in an embodiment of the present invention;

[0029] Figure 2 Schematic cross-sectional view of the magnetic circuit system in an embodiment of the present invention;

[0030] Figure 3 Schematic cross-sectional view of the magnetic circuit system in an embodiment of the present invention;

[0031] Figure 4 Schematic enlarged partial cross-sectional view of the magnetic circuit system in an embodiment of the present invention;

[0032] Figure 5 Schematic cross-sectional view of the U-shaped iron in an embodiment of the present invention;

[0033] Figure 6 Schematic diagram of the simulated magnetic induction lines of a part of the magnetic circuit system in an embodiment of the present invention;

[0034] Figure 7 Schematic diagram of the simulated magnetic induction lines of a part of the magnetic circuit system in the prior art;

[0035] Figure 8 BL curve graph of the sound generating device of the present invention and the prior art in an embodiment of the present invention.

[0036] Explanation of the reference numerals in the drawings:

[0037] Label Name Label Name 100 Sound generating device 222 Inner washer 1 Basket 2221 Notch groove 11 Cavity 2222 Recessed groove 12 Limit groove 223 Short-circuit ring 13 Fixed platform 2231 First section 2 Magnetic circuit system 2232 Second section 21 U-shaped iron 23 Outer magnetic circuit part 211 Receiving groove 231 Outer magnet 212 Support surface 232 Outer washer 213 Boss 2321 Limit protrusion 214 Avoidance groove 24 Magnetic gap 215 Groove 3 Vibration system 216 Support platform 31 Diaphragm 22 Inner magnetic circuit part 32 Voice coil 221 Inner magnet 33 Centering ring

[0038] The realization of the object of the present invention, functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0041] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously.

[0042] In addition, in the present invention, descriptions such as "first", "second", etc. are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. Additionally, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or inability to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0043] A horn, also known as a loudspeaker, is an electroacoustic transducer that converts electrical energy into sound energy through a certain physical effect. When different electrical energies are transmitted to the voice coil of the horn, the voice coil generates an energy that interacts with the magnetic field of the magnet. This interaction causes the diaphragm to vibrate. Since the electrical energy changes at any time, the voice coil of the horn moves forward or backward, and thus the diaphragm of the horn follows the movement. This action causes changes in the density of the air to produce sound.

[0044] In the related art, the washer of the loudspeaker is mostly cylindrical or circular, and is adhered to the magnet with glue, and forms the magnetic circuit system of the loudspeaker together with the U-shaped iron or T-shaped iron. The washer plays a role in guiding magnetism, and forms a magnetic circuit together with the U-shaped iron or T-shaped iron and the magnet, so that the energized voice coil makes a cutting magnetic induction line movement therein, driving the diaphragm to vibrate and generate sound. However, the magnetic permeability of some areas of the disc-shaped or circular washer is very low. Retaining the areas with low magnetic permeability leads to an increase in the weight of the washer, which cannot meet the design requirements of miniaturization and light weight, and there are also problems with poor BL value and linear range.

[0045] Based on the above concept and problems, the present invention proposes a sound generating device 100. It can be understood that the sound generating device 100 is applied to a terminal device, and the terminal device can be a speaker, a car speaker, etc., which is not limited herein.

[0046] Please refer to Figures 1 to 5As shown, in the embodiment of the present invention, the sound generating device 100 includes a chassis 1, a magnetic circuit system 2, and a vibration system 3. Among them, the chassis 1 is provided with a cavity 11 with both ends open. The magnetic circuit system 2 includes a U-shaped iron 21, an inner magnetic circuit part 22, and an outer magnetic circuit part 23. The U-shaped iron 21 has a receiving groove 211. The inner magnetic circuit part 22 is arranged in the receiving groove 211. The end face of the U-shaped iron 21 adjacent to the notch of the receiving groove 211 forms a supporting surface 212. The outer magnetic circuit part 23 is arranged on the supporting surface 212 and is connected to the chassis 1. The outer magnetic circuit part 23 and the U-shaped iron 21 cooperate to cover the opening at one end of the cavity 11. The side wall of the receiving groove 211 and the outer magnetic circuit part 23 are spaced from the inner magnetic circuit part 22 to form a magnetic gap 24. A notch groove 2221 is provided on one side of the inner magnetic circuit part 22 facing the magnetic gap 24. The vibration system 3 includes a diaphragm 31 and a voice coil 32 connected to the diaphragm 31. The diaphragm 31 is connected to the chassis 1 and covers the opening at the other end of the cavity 11. The end of the voice coil 32 away from the diaphragm 31 is suspended in the magnetic gap 24.

[0047] In this embodiment, the chassis 1 is used to install, fix, support, and protect components such as the vibration system 3 and the magnetic circuit system 2. That is, the chassis 1 provides an installation foundation for components such as the vibration system 3 and the magnetic circuit system 2. It can be understood that the chassis 1 can be a structure such as an installation shell, a housing, or a box body with a cavity 11. That is, the chassis 1 defines a receiving space, which is not limited here.

[0048] It can be understood that the chassis 1 can be selected as a cylindrical, square, or horn-shaped structure, etc. The cavity 11 of the chassis 1 can be a cavity structure with one end open. Of course, it can also be a cavity structure with both ends open. Optionally, the chassis 1 is a horn-shaped or basin-shaped structure with both ends open. In this embodiment, the chassis 1 is a columnar or basin-shaped structure with both ends open. The magnetic circuit system 2 is arranged at the opening at one end of the chassis 1. By connecting and fixing the periphery of the diaphragm 31 of the vibration system 3 to the other end of the chassis 1 and covering the opening at the other end, the diaphragm 31 is opposite to the magnetic circuit system 2, and a vibration space of the sound generating device 100 is formed by enclosing with the chassis 1.

[0049] In this embodiment, the magnetic circuit system 2 includes a U-shaped iron 21, an inner magnetic circuit portion 22, and an outer magnetic circuit portion 23. The U-shaped iron 21 is arranged in a U shape. At this time, the U-shaped iron 21 has a receiving groove 211 with one end open. The U-shaped iron 21 is arranged at the open end of the chassis 1. The receiving groove 211 of the U-shaped iron 21 communicates with the cavity 11. The notch of the receiving groove 211 faces the diaphragm 31. The end face of the U-shaped iron 21 adjacent to the notch of the receiving groove 211 forms a supporting surface 212. The outer magnetic circuit portion 23 is arranged on the supporting surface 212 and is connected to the chassis 1. The inner magnetic circuit portion 22 is arranged in the receiving groove 211, so that the side wall of the receiving groove 211 and the outer magnetic circuit portion 23 are spaced apart from the inner magnetic circuit portion 22 to form a magnetic gap 24. The voice coil 32 of the vibration system 3 is located in the vibration space of the sound generating device 100, so that one end of the voice coil 32 is connected to the diaphragm 31, and the other end of the voice coil 32 is suspended in the magnetic gap 24. In this way, when the voice coil 32 is energized, the voice coil 32 introduces electrical energy into the magnetic gap 24 of the magnetic circuit system 2. Under the action of the magnetic field of the magnetic circuit system 2, the voice coil 32 is driven to cut the magnetic induction line, so that the electrical energy is converted into mechanical energy. When the voice coil 32 moves, it drives the diaphragm 32 to vibrate, so that the diaphragm 32 vibrates and generates sound, so that the mechanical energy is converted into sound energy, realizing electro-acoustic conversion.

[0050] It can be understood that when the chassis 1 is a metal part, the magnetic circuit system 2 and the chassis 1 are fixed by bonding or welding, so as to improve the heat dissipation effect of the sound generating device 100. In another embodiment, when the chassis 1 is injection molded of plastic, the magnetic conduction plate of the outer magnetic circuit portion 23 of the magnetic circuit system 2 can also be used as an insert and injection molded into the chassis 1, or the magnetic circuit system 2 and the chassis 1 are fixed by bonding, and then other parts are fixed by bonding, which is not limited here.

[0051] In this embodiment, the inner magnetic circuit portion 22 is arranged in the receiving groove 211, which can reduce the longitudinal space of the sound generating device 100, reduce the product height, and can be used in a smaller space, realizing the miniaturization of the product. At the same time, compared with the traditional design, this structure avoids the interference between the diaphragm 31 and the magnetic circuit system 2 during large-amplitude operation. At the same time, the outer magnetic circuit portion 23 is arranged on the supporting surface 212 formed on the end face of the U-shaped iron 21 adjacent to the notch of the receiving groove 211, so as to further increase the magnetic field intensity.

[0052] In this embodiment, as Figures 1 to 4As shown, by installing and fixing the outer magnetic circuit part 23 on the end face of the U-shaped iron 21 and arranging the inner magnetic circuit part 22 in the accommodating groove 211 of the U-shaped iron 21, the inner magnetic circuit part 22, the outer magnetic circuit part 23 and the U-shaped iron 21 are used to increase the magnetic field strength and magnetic flux density, so as to increase the driving force on the voice coil 32. At the same time, by providing a notch groove 2221 on one side of the inner magnetic circuit part 22 facing the magnetic gap 24, that is, by providing the notch groove 2221 on the inner magnetic circuit part 22, the part with low magnetic permeability on the inner magnetic circuit part 22 is cancelled, thereby reducing the weight of the inner magnetic circuit part 22. In this way, the part with high magnetic permeability of the inner magnetic circuit part 22 can be fully utilized to ensure good BL value and linear range of the sound generating device 100 while meeting the design requirements of miniaturization and light weight.

[0053] The sound generating device 100 of the present invention forms a cavity 11 with both ends open in the chassis 1, so as to install, fix and protect the magnetic circuit system 2 and the vibration system 3 by using the chassis 1. The magnetic circuit system 2 is set as the U-shaped iron 21, the inner magnetic circuit part 22 and the outer magnetic circuit part 23. The inner magnetic circuit part 22 is installed and fixed by using the accommodating groove 211 of the U-shaped iron 21, and the outer magnetic circuit part 23 is arranged on the supporting surface 212 of the U-shaped iron 21, so that the inner magnetic circuit part 22, the side wall of the accommodating groove 211 of the U-shaped iron 21 and the outer magnetic circuit part 23 enclose a magnetic gap 24 for the voice coil 32 of the vibration system 3 to be suspended. In this way, after the voice coil 32 is energized, the voice coil 32 makes a movement of cutting the magnetic induction line in the magnetic gap 24 of the magnetic circuit system 2, thereby driving the diaphragm 31 to vibrate and generate sound; by providing a notch groove 2221 on one side of the inner magnetic circuit part 22 facing the magnetic gap 24, the part with low magnetic permeability of the inner magnetic circuit part 22 is cancelled, so as to reduce the weight of the inner magnetic circuit part 22 and make full use of the part with high magnetic permeability of the inner magnetic circuit part 22 to ensure good BL value and linear range of the sound generating device 100 while meeting the design requirements of miniaturization and light weight.

[0054] In an embodiment, the inner magnetic circuit part 22 includes an inner magnet 221 and an inner washer 222 arranged in a stacked manner. The inner magnet 221 is clamped between the inner washer 222 and the bottom wall of the accommodating groove 211, and a notch groove 2221 is provided on one side of the inner washer 222 facing the magnetic gap 24; the outer magnetic circuit part 23 includes an outer magnet 231 and an outer washer 232 arranged in a stacked manner. The outer magnet 231 is clamped between the outer washer 232 and the supporting surface 212, and the outer washer 232 is connected to the chassis 1.

[0055] In this embodiment, as Figures 1 to 4As shown, the inner magnetic circuit part 22 includes an inner magnet 221 and an inner washer 222. The inner magnet 221 can be selected as a magnet, and the inner washer 222 can be selected as a magnetic conductive plate structure. The shape profile of the inner magnet 221 is the same as or consistent with that of the inner washer 222. Optionally, the inner magnet 221 and the inner washer 222 can be circular, oval, square, or racetrack-shaped, etc., which are not limited herein. It can be understood that the outer magnetic circuit part 23 includes an outer magnet 231 and an outer washer 232. The outer magnet 231 can be selected as a magnet, and the outer washer 232 can be selected as a magnetic conductive plate structure. The shape profile of the outer magnet 231 is the same as or consistent with that of the outer washer 232. Optionally, the outer magnet 231 and the outer washer 232 can be circular ring, oval ring, square ring, or racetrack ring-shaped, etc., which are not limited herein.

[0056] It can be understood that the shape profiles of the inner magnet 221 and the inner washer 222 of the inner magnetic circuit part 22 are generally similar to the shape profile of the receiving groove 211 of the U-shaped iron 21, and the shape profiles of the outer magnet 231 and the outer washer 232 of the outer magnetic circuit part 23 are generally similar to the shape profile of the notch of the receiving groove 211 of the U-shaped iron 21. Optionally, the U-shaped iron 21 is a cylindrical structure with one end open. In this embodiment, the supporting surface 212 of the U-shaped iron 21 is adhesively fixed to the outer magnet 231 of the outer magnetic circuit part 23, the outer magnet 231 and the outer washer 232 are adhesively fixed to each other, and the outer magnetic circuit part 23 is fixedly connected to the chassis 1 through the outer washer 232.

[0057] Optionally, the outer washer 232 and the chassis 1 can be connected by welding, bonding, or integrally forming, etc., which are not limited herein. In this embodiment, as Figures 1 to 5 shown, a limiting protrusion 2321 protrudes from the side of the outer washer 232 facing away from the magnetic gap 24, and the chassis 1 is provided with a limiting groove 12. The limiting protrusion 2321 is received and limited in the limiting groove 12. It can be understood that by setting it like this, the connection stability between the chassis 1 and the outer magnetic circuit part 23 can be improved, and the limiting installation of the magnetic circuit system 2 can be realized.

[0058] In one embodiment, as Figures 1 to 4 shown, a recessed groove 2222 is provided on the side of the inner washer 222 facing away from the inner magnet 221.

[0059] In this embodiment, by providing a notch groove 2221 on the side of the inner washer 222 facing the magnetic gap 24 and a recessed groove 2222 on the side of the inner washer 222 facing away from the inner magnet 221, the inner washer 222 is formed into a stepped structure, so as to further cooperate with the notch groove 2221 and the recessed groove 2222 to cancel the part with low magnetic permeability on the inner washer 222, reduce the weight of the inner washer 222, achieve the purpose of weight reduction, and ensure the magnetic permeability and magnetic field strength of the inner washer 222 under the action of the inner magnet 221.

[0060] In this embodiment, the notch groove 2221 can be structures such as a notch or a groove. The recessed groove 2222 can be optionally a groove structure or a through groove structure, etc., which is not limited herein. The recessed groove 2222 is recessed from the side of the inner washer 222 facing away from the inner magnet 221 towards the inner magnet 221. Optionally, the recessed groove 2222 is located in the middle of the inner washer 222.

[0061] To further increase the magnetic flux density at the magnetic gap 24, the inner wall of the recessed groove 2222 is arranged as an arc surface, so that the air flow generated by the vibration of the diaphragm 31 flows more smoothly. In this embodiment, as Figures 6 to 8 shown, the notch groove 2221 and the recessed groove 2222 of the inner washer 222 of the present invention cooperate to remove the part with low magnetic permeability on the inner washer 222, which can increase the magnetic flux density of the inner washer 222. Thus, on the premise of ensuring the magnetic flux, the weight of the inner washer 222 can be effectively reduced, the use efficiency of the inner washer 222 can be improved, and the BL curve is more symmetrical, and the force on the voice coil 32 during the reciprocating vibration is more balanced, and the vibration state is more stable.

[0062] It can be understood that in order to ensure that when the voice coil 32 of the vibration system 3 makes a cutting magnetic induction line movement in the magnetic gap 24, a constant number of voice coils can maintain the maximum displacement in the magnetic gap 23. The voice coil 32 adopts a long voice coil and is matched with a stepped inner washer 222, so that the inner washer 222 is stepped adjacent to the magnetic gap 24, which can increase the magnetic flux density at the magnetic gap 24, ensure that the sound generating device 100 has high sensitivity, and increase the linear range of the sound generating device 100 while ensuring the BL value.

[0063] Optionally, the notch groove 2221 extends along the periphery of the inner washer 222. Thus, the notch groove 2221 extends along the circumferential direction of the magnetic gap 24 to form an annular groove structure on the outer side wall of the inner washer 222. To further ensure the magnetic flux density of the inner washer 222 at the magnetic gap 24, the notch groove 2221 is arranged adjacent to the inner magnet 221.

[0064] In this embodiment, the notch groove 2221 penetrates the bottom surface of the inner washer 222 facing the inner magnet 221, so that the outer side wall of the inner washer 222 facing the magnetic gap 24 is arranged in a stepped manner. It can be understood that the recessed groove 2222 can be optionally a semi-circular groove or a hemispherical groove. The connection between the groove wall of the recessed groove 2222 and the surface of the side of the inner washer 222 facing away from the inner magnet 221 is provided with a fillet or an arc transition, so that the air flow generated by the vibration of the diaphragm 31 can flow more smoothly.

[0065] Optionally, the inner wall of the recessed groove 2222 includes a connected convex arc surface and a concave arc surface, and the side of the convex arc surface away from the concave arc surface is connected to the outer side wall of the inner washer 222.

[0066] In this embodiment, asFigures 1 to 4 As shown, by setting the inner wall of the recessed groove 2222 as a connected convex arc surface and concave arc surface, the convex arc surface is located at the edge of the concave arc surface and is connected to the outer side wall of the bobbin 222, so as to ensure that the upper end of the bobbin 222 is smoothly transitioned, to uniformize the magnetic induction lines and further increase the magnetic flux density at the magnetic gap 24. Optionally, the connection between the convex arc surface and the concave arc surface is smoothly transitioned, that is, the inner wall of the recessed groove 2222 is a smooth arc surface structure, so that the airflow generated by the vibration of the diaphragm 31 flows more smoothly, reducing the interference caused by the airflow impact on the magnetic circuit system 2.

[0067] In an embodiment, define the thickness of the inner magnet 221 as h1 and the thickness of the outer magnet 231 as h2, where 0.8 ≤ h1 / h2 ≤ 1.2. It can be understood that, as Figure 3 and Figure 4 shown, the thickness h1 of the inner magnet 221 is the thickness of the inner magnet 221 along the moving direction of the voice coil 32 or the vibration direction of the diaphragm 31, and the thickness h2 of the outer magnet 231 is the thickness of the outer magnet 231 along the moving direction of the voice coil 32 or the vibration direction of the diaphragm 31.

[0068] In this embodiment, by controlling the ratio of the thickness h1 of the inner magnet 221 to the thickness h2 of the outer magnet 231 within the range of 0.8 to 1.2, the magnetic field distribution of the magnetic circuit system 2 is made more uniform, and the magnetic field intensity is maximized within the limited space and cost range. Optionally, the ratio of the thickness h1 of the inner magnet 221 to the thickness h2 of the outer magnet 231 is 0.8, 0.9, 1, 1.1, 1.2, etc., which is not limited here.

[0069] In an embodiment, define the maximum thickness of the bobbin 222 as t1 and the thickness of the outer bobbin 232 as t2, where 2 ≤ t1 / t2 ≤ 2.5. It can be understood that, as Figure 3 and Figure 4 shown, the maximum thickness t1 of the bobbin 222 is the maximum distance between the side of the bobbin 222 facing away from the inner magnet 221 and the side of the bobbin 222 facing the inner magnet 221, the thickness of the bobbin 222 is the thickness of the bobbin 222 along the moving direction of the voice coil 32 or the vibration direction of the diaphragm 31, and the thickness t2 of the outer bobbin 232 is the thickness of the outer bobbin 232 along the moving direction of the voice coil 32 or the vibration direction of the diaphragm 31.

[0070] In this embodiment, by controlling the ratio of the maximum thickness t1 of the inner washer 222 to the thickness t2 of the outer washer 232 within the range of 2 to 2.5, the magnetic field distribution of the magnetic circuit system 2 becomes more uniform, and the magnetic field intensity is maximized within a limited space and cost range. Optionally, the ratio of the maximum thickness t1 of the inner washer 222 to the thickness t2 of the outer washer 232 is 2, 2.1, 2.2, 2.3, 2.4, 2.5, etc., which is not limited herein.

[0071] In one embodiment, as Figure 3 and Figure 4 shown, define the radius of the inner washer 222 as d1, and define the width of the outer washer 232 as d2, where 1.5 ≤ d1 / d2 ≤ 2. It can be understood that the inner washer 222 can be selected as a disc structure, and the radius d1 of the inner washer 222 is the radius of the surface of the inner washer 222 facing away from the inner magnet 221, and the outer washer 232 can be selected as an annular structure.

[0072] In this embodiment, by controlling the ratio of the radius d1 of the inner washer 222 to the width d2 of the outer washer 232 within the range of 1.5 to 2, the magnetic field distribution of the magnetic circuit system 2 becomes more uniform, and the magnetic field intensity is maximized within a limited space and cost range. Optionally, the ratio of the radius d1 of the inner washer 222 to the width d2 of the outer washer 232 is 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc., which is not limited herein.

[0073] In one embodiment, as Figures 1 to 4 shown, the cross-section of the recessed groove 2222 is semi-circular. Define the radius of the recessed groove 2222 as R, define the maximum thickness of the inner washer 222 as t1, and define the radius of the inner washer 222 as d1, where t1 < R < d1.

[0074] In this embodiment, the inner washer 222 is cut from the middle along the moving direction of the voice coil 32 or the vibration direction of the diaphragm 31. The cross-section of the recessed groove 2222 is semi-circular. By limiting the radius R of the recessed groove 2222 between the maximum thickness t1 of the inner washer 222 and the radius d1 of the inner washer 222, the length of the outer wall of the inner washer 222 adjacent to the magnetic gap 24 is ensured, so as to ensure the magnetic flux density of the inner washer 222 at the magnetic gap 24.

[0075] In one embodiment, the inner magnetic circuit portion 22 further includes a short-circuit ring 223. The short-circuit ring 223 includes a first section 2231 and a second section 2232 arranged at an angle. The first section 2231 is connected to the side of the inner washer 222 facing away from the inner magnet 221, and the second section 2232 is attached to the side of the inner washer 222 facing the magnetic gap 24 and extends to the inner magnet 221 to cover the notch groove 2221.

[0076] In this embodiment, asFigures 1 to 4 As shown, by providing the short - circuit ring 223, the back electromotive force of the voice coil 32 in the magnetic gap 24 can be effectively reduced by using the short - circuit ring 223, so as to reduce the inductance and improve the high - frequency sensitivity. Optionally, the short - circuit ring 223 is made of copper.

[0077] It can be understood that the short - circuit ring 223 has an annular cylindrical structure. As Figures 1 to 4 shown, the short - circuit ring 223 includes a first section 2231 and a second section 2232 arranged at an angle. Optionally, the first section 2231 and the second section 2232 are arranged perpendicularly. The first section 2231 is connected to the side of the bobbin 222 facing away from the inner magnet 221, and the first section 2231 has an opening corresponding to the recessed groove 2222, that is, the recessed groove 2222 is exposed at this opening. The second section 2232 is attached to the side of the bobbin 222 facing the magnetic gap 24 and extends to the inner magnet 221 to cover the notch groove 2221.

[0078] In an embodiment, as Figure 4 shown, the length of the notch groove 2221 along the axis direction of the magnetic gap 24 is defined as a, and the length of the notch groove 2221 along the direction perpendicular to the axis of the magnetic gap 24 is defined as b; wherein, 1.8 ≤ a / b ≤ 2.2.

[0079] In this embodiment, the axis direction of the magnetic gap 24 is the moving direction of the voice coil 32, and the direction perpendicular to the axis of the magnetic gap 24 is the direction from the inner magnetic circuit part 22 to the side wall of the accommodating groove 211 of the U - shaped iron 21. By providing a notch groove 2221 on the side of the inner magnetic circuit part 22 facing the magnetic gap 24, defining the length of the notch groove 2221 along the axis direction of the magnetic gap 24 as a and the length of the notch groove 2221 along the direction perpendicular to the axis of the magnetic gap 24 as b, such that the ratio range of the length a of the notch groove 2221 along the axis direction of the magnetic gap 24 to the length b of the notch groove 2221 along the direction perpendicular to the axis of the magnetic gap 24 is within the range of 1.8 - 2.2, thereby by providing the notch groove 2221 on the inner magnetic circuit part 22, the part with low magnetic permeability on the inner magnetic circuit part 22 is eliminated, so as to reduce the weight of the inner magnetic circuit part 22. In this way, the part with high magnetic permeability of the inner magnetic circuit part 22 can be fully utilized to ensure good BL value and linear range of the sound - generating device 100 while meeting the design requirements of miniaturization and light weight.

[0080] Optionally, the ratio of the length a of the notch groove 2221 along the axis direction of the magnetic gap 24 to the length b of the notch groove 2221 along the direction perpendicular to the axis of the magnetic gap 24 is 1.8, 1.9, 2, 2.1, 2.2, etc., which is not limited herein.

[0081] In one embodiment, a boss 213 protrudes from the bottom wall of the receiving groove 211. The boss 213 is spaced from the side wall of the receiving groove 211 and encloses an avoidance groove 214 communicating with the receiving groove 211. The avoidance groove 214 corresponds to the magnetic gap 24, and the inner magnetic circuit portion 22 is supported on the boss 213.

[0082] In this embodiment, as Figures 1 to 5 shown, by providing a boss 213 on the bottom wall of the receiving groove 211 of the U-shaped iron 21, the boss 213 is spaced from the side wall of the receiving groove 211 to enclose an avoidance groove 214, and the avoidance groove 214 corresponds to and communicates with the magnetic gap 24. Thus, while using the boss 213 to support and fix the inner magnetic circuit portion 22, the avoidance groove 214 is used to avoid the movement of the voice coil 32 in the magnetic gap 24 to ensure the amplitude of the sound generating device 100.

[0083] It can be understood that the boss 213 may be a convex structure protruding from the bottom wall of the receiving groove 211. Of course, the boss 213 may also be formed by protruding from the side of the U-shaped iron 21 facing away from the bottom wall of the receiving groove 211 into the receiving groove 211, which is not limited herein. Optionally, a groove 215 is recessed on the side of the U-shaped iron 21 facing away from the notch of the receiving groove 211, that is, a groove 215 is recessed corresponding to the boss 213 on the side of the U-shaped iron 21 facing away from the bottom wall of the receiving groove 211.

[0084] In this embodiment, in order to ensure the air pressure balance in the vibration space when the voice coil 32 drives the diaphragm 31 to vibrate, a through hole is provided on the chassis 1, and the through hole communicates with the vibration space. Of course, a through hole structure may also be provided on the inner magnetic circuit portion 22 corresponding to the through hole. Optionally, the through hole is opened on the bottom wall of the cavity 11 of the chassis 1 and penetrates the bottom wall of the cavity 11.

[0085] In one embodiment, as Figure 1 shown, the vibration system 3 further includes a centering ring 33. The inner side of the centering ring 33 is connected to the outer wall of the voice coil 32, and a fixing platform 13 protrudes from the chassis 1. The outer side of the centering ring 33 is connected to the fixing platform 13. It can be understood that by providing the centering ring 33, the centering ring 33 is effectively used to prevent the voice coil 32 from being polarized or swinging left and right during vibration, so as to improve the vibration and sound generation effect of the diaphragm 31.

[0086] It can be understood that the fixing platform 13 may be a boss structure convexly provided on the inner wall of the cavity 11, or a stepped structure formed by the inner wall of the cavity 11, which is not limited herein.

[0087] In one embodiment, as Figures 1 to 5As shown, the yoke 21 extends toward the side away from the receiving groove 211 adjacent to the supporting surface 212 to form a supporting platform 216. The supporting platform 216 is flush with the supporting surface 212, and the outer magnetic circuit portion 23 is supported on the supporting surface 212 and the supporting platform 216. It can be understood that by providing the supporting platform 216, the contact area with the outer magnetic circuit portion 23 is increased by using the supporting platform 216 and the supporting surface 212, so as to improve the connection stability between the outer magnetic circuit portion 23 and the yoke 21.

[0088] The present invention also provides a terminal device, which includes a device housing and the above-mentioned sound generating device 100. The sound generating device 100 is disposed in the device housing. The specific structure of the sound generating device 100 refers to the foregoing embodiments. Since this terminal device adopts all the technical solutions of all the foregoing embodiments, it at least has all the beneficial effects brought by the technical solutions of the foregoing embodiments, which will not be elaborated herein one by one.

[0089] The above are only the optional embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A sound generating device, characterized in that, The sound generating device includes: a chassis having a cavity with openings at both ends; a magnetic circuit system including a U-shaped iron, an inner magnetic circuit portion, and an outer magnetic circuit portion. The U-shaped iron has a receiving groove, the inner magnetic circuit portion is disposed in the receiving groove, an end face of the U-shaped iron adjacent to the opening of the receiving groove forms a supporting surface, the outer magnetic circuit portion is disposed on the supporting surface and connected to the chassis. The outer magnetic circuit portion and the U-shaped iron cooperate to cover an opening at one end of the cavity. A side wall of the receiving groove, the outer magnetic circuit portion, and the inner magnetic circuit portion are spaced apart to form a magnetic gap. The inner magnetic circuit portion includes an inner magnet and an inner washer stacked together. The inner magnet is clamped between the inner washer and the bottom wall of the receiving groove. A notch groove is provided on a side of the inner washer facing the magnetic gap, and the notch groove penetrates the bottom surface of the inner washer facing the magnet. A recessed groove is provided on a side of the inner washer facing away from the inner magnet, and the recessed groove and the notch groove are portions with low magnetic permeability of the inner washer; and a vibration system including a diaphragm and a voice coil connected to the diaphragm. The diaphragm is connected to the chassis and covers an opening at the other end of the cavity. One end of the voice coil away from the diaphragm is suspended in the magnetic gap.

2. The sound generating device according to claim 1, wherein, The outer magnetic circuit portion includes an outer magnet and an outer washer stacked together. The outer magnet is clamped between the outer washer and the supporting surface, and the outer washer is connected to the chassis.

3. The sound generating device according to claim 2, wherein, Define the thickness of the inner magnet as h1 and the thickness of the outer magnet as h2, where 0.8 ≤ h1 / h2 ≤ 1.2; and / or, define the maximum thickness of the inner washer as t1 and the thickness of the outer washer as t2, where 2 ≤ t1 / t2 ≤ 2.5; and / or, define the radius of the inner washer as d1 and the width of the outer washer as d2, where 1.5 ≤ d1 / d2 ≤ 2; and / or, the cross section of the recessed groove is semicircular. Define the radius of the recessed groove as R, the maximum thickness of the inner washer as t1, and the radius of the inner washer as d1, where t1 < R < d1.

4. The sound generating device according to claim 2, wherein The notch groove extends along the circumference of the inner washer; and / or, the notch groove is adjacent to the inner magnet; and / or, a limiting protrusion protrudes from a side of the outer washer facing away from the magnetic gap, and the chassis is provided with a limiting groove, and the limiting protrusion is received and limited in the limiting groove.

5. The sound generating device according to claim 1, wherein, The inner magnetic circuit portion further includes a short-circuit ring. The short-circuit ring includes a first section and a second section disposed at an angle. The first section is connected to a side of the inner washer facing away from the inner magnet, and the second section adheres to a side of the inner washer facing the magnetic gap and extends to the inner magnet to cover the notch groove.

6. The sound generating device according to any one of claims 1 to 5, characterized in that Define the length of the notch groove along the axis direction of the magnetic gap as a, and the length of the notch groove along a direction perpendicular to the axis direction of the magnetic gap as b; where 1.8 ≤ a / b ≤ 2.

2.

7. The sound generating device according to any one of claims 1 to 5, characterized in that The bottom wall of the accommodating groove is provided with a boss, the boss is spaced from the side wall of the accommodating groove, and encloses a avoidance groove connected to the accommodating groove, the avoidance groove corresponds to the magnetic gap, and the inner magnetic circuit is partially supported by the boss; And / or, a groove is formed on a side of the U iron facing away from the notch of the accommodating groove.

8. The sound generating device according to any one of claims 1 to 5, characterized in that, The vibration system further comprises a centering ring, the inner side of which is connected to the outer wall of the voice coil, the basin frame is convexly provided with a fixing platform, the outer side of which is connected to the fixing platform; And / or, the U iron extends adjacent to the supporting surface toward a side away from the accommodating groove to form a supporting platform, the supporting platform is flush with the supporting surface, and the external magnetic circuit is partially supported by the supporting surface and the supporting platform.

9. A terminal device, characterized in that, The device comprises a device housing and a sound-generating device as claimed in any one of claims 1 to 8, wherein the sound-generating device is arranged in the device housing.

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