Positive and negative air pushing double-voice-diaphragm automobile sound equipment

Abstract

The invention discloses a positive and negative air-propelled double-diaphragm automobile audio, which comprises a permanent magnet, a magnetic ring is coaxially mounted on the radial outer side of the permanent magnet, a magnetic conductive ring is coaxially arranged on the radial outer side of the magnetic ring, and a first gap with an opening facing the axial left end of the permanent magnet is arranged between the permanent magnet and the magnetic ring. A second gap facing the axial right end of the permanent magnet is arranged between the magnetic ring and the magnetic conductive ring, a left loudspeaker assembly and a right loudspeaker assembly are installed at the axial left end and the axial right end of the magnetic conductive ring respectively, a left voice coil in the left loudspeaker assembly extends into the first gap, and a right voice coil in the right loudspeaker assembly extends into the second gap. The permanent magnet comprises a left-section permanent magnet matched with the left voice coil, a right-section permanent magnet matched with the right voice coil, and a middle isolation layer located between the left voice coil and the right voice coil. The problems that an existing automobile sound box is large in size, the air pushing amount of a single sound box is small, and two independent loudspeakers are prone to mutual interference when working can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile audio, in particular to a dual-diaphragm automobile audio system with positive and negative air push. Background Art

[0002] Traditional in-car audio systems, designed to cover both the front and rear rows, typically require separate speakers installed at the front and rear of the vehicle (e.g., one or two speakers each for the front and rear doors). Each speaker contains core components such as permanent magnets and magnetic circuit components, resulting in a large overall installation space requirement. Traditional unidirectional speakers (e.g., facing forward or backward) exhibit significant directionality in sound wave propagation, leading to sound pressure level differences of up to 8-15dB between the front and rear seats, and between the left and right sides of the vehicle. Furthermore, the air displacement of existing single-diaphragm speakers is limited by the diaphragm's area and amplitude. Low-frequency signals (e.g., below 60Hz) require a large volume of air to effectively reproduce them, but the limited air displacement of a single diaphragm results in insufficient low-frequency depth. If two independent speakers are used in conjunction, the resonant frequencies of their vibration systems (voice coil, damper, diaphragm) may differ, leading to mutual interference and increased total harmonic distortion (THD) to over 1%. Especially at high volumes, this distortion can mask musical details and compromise the purity of the sound quality. Summary of the Invention

[0003] The present invention provides a dual-diaphragm car audio system with positive and negative air propulsion, which can solve the problems of the existing car audio system being relatively large in size, the air propulsion volume of a single speaker being relatively small, and the two independent speakers being easily interfered with each other when working.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a positive and negative air-propelled dual-diaphragm car audio system, comprising a permanent magnet, a magnetic ring coaxially mounted on the radial outer side of the permanent magnet, a magnetic conductive ring coaxially mounted on the radial outer side of the magnetic ring, a first gap opening toward the axial left end of the permanent magnet is provided between the permanent magnet and the magnetic ring, a second gap opening toward the axial right end of the permanent magnet is provided between the magnetic ring and the magnetic conductive ring, a left speaker assembly and a right speaker assembly are respectively mounted on the axial left end and the axial right end of the magnetic conductive ring, the left voice coil in the left speaker assembly extends into the first gap, and the right voice coil in the right speaker assembly extends into the second gap, the permanent magnet comprises a left-segment permanent magnet matching the left voice coil, a right-segment permanent magnet matching the right voice coil, and an intermediate isolation layer located between the left voice coil and the right voice coil. The left end face of the left section permanent magnet is an N pole, and the right end face is an S pole. The left end face of the right section permanent magnet is an S pole, and the right end face is an N pole. The design of the left speaker component and the right speaker component sharing one permanent magnet eliminates the extra permanent magnets and supporting magnetic circuit components in the traditional dual-speaker solution. The left speaker component and the right speaker component emit sound to both sides respectively, which can cover the front and back or left and right directions in the car. When the dual sound membranes work at the same time, the total air pushing area is times that of the single sound membrane. With the coordinated vibration of the dual voice coils, the air displacement is significantly increased. The left and right speaker components adopt a symmetrical structure design with opposite vibration directions, which can offset some harmful vibrations. The permanent magnet adopts a segmented structure to realize N→S and S→N reverse magnetic fields in a single integrated permanent magnet, and realizes stable output of reverse magnetic fields on a single permanent magnet, eliminating additional magnets while improving magnetic field efficiency.

[0005] Preferably, the right end face of the left-segment permanent magnet and the left end face of the right-segment permanent magnet are both provided with tapered side portions, so that the docking area of ​​the left-segment permanent magnet and the right-segment permanent magnet forms a V-shaped magnetic field transition zone. This structure can reduce the sudden change of the magnetic field at the boundary, and reduce the rate of change of the magnetic field intensity between the first gap and the second gap from 20% / mm of the traditional right-angle docking to 5% / mm, thereby improving the stability of the force on the voice coil. Through the tapered transition design, the continuity of the magnetic field at the boundary between the two sections is improved.

[0006] Preferably, the intermediate isolation layer is a polyimide film with a thickness of no more than 0.1 mm. The intermediate isolation layer can avoid magnetic field short circuit caused by direct contact between the two permanent magnets, and at the same time buffer the magnetic field interference during magnetization, ensuring that the boundaries of the two magnetization directions are clear. The thickness of the intermediate isolation layer is less than 0.1 mm to avoid affecting the continuity of the magnetic field.

[0007] Preferably, the left voice coil includes a tubular hollow frame and a plurality of multi-layer wire groups wound around the right end of the tubular hollow frame, and the right voice coil includes a tubular frame, a single-layer wire coil is sparsely wound on the left end of the tubular frame, and a solid portion is provided inside the right end of the tubular frame. The weight of the right voice coil is greater than that of the left voice coil. Through the different arrangements of the multi-layer wire groups and the wire coils, the inductance of the left voice coil is smaller than that of the right voice coil, forming a dynamic match with the characteristic that the weight of the right voice coil is greater than that of the left voice coil, thereby further suppressing the mutual inductance fluctuations caused by vibration coupling.

[0008] Preferably, the weight ratio of the left voice coil to the right voice coil is 1:2, so that the inertia of the right voice coil can offset part of the vibration during the reverse movement, and can also match the inductance ratio between the left voice coil and the right voice coil.

[0009] Preferably, the wire diameter of the wire coil on the right voice coil is larger than the wire diameter of the multi-layer wire group on the left voice coil, and the winding spiral pitch of the wire coil gradually increases from the left end to the right end. Such a structural setting can adapt to the axial displacement difference during low-frequency vibration.

[0010] Preferably, the left speaker assembly also includes a left basin frame connected to the axial left end of the magnetic ring, and the left basin frame is equipped with a left elastic wave and a left sound membrane connected to the left voice coil. The right speaker assembly also includes a right basin frame connected to the axial right end of the magnetic ring, and the right basin frame is equipped with a right elastic wave and a right sound membrane connected to the right voice coil. The structure is simple, the installation is convenient, and the left sound membrane and the right sound membrane are in opposite directions.

[0011] Preferably, foam gaskets are installed on the right side of the end surface of the left basin frame and the right side of the end surface of the right basin frame, which can improve the vibration reduction effect of the entire audio system during installation.

[0012] Preferably, dust covers are installed in the middle of the left and right sound diaphragms to prevent external impurities from entering the left and right voice coils.

[0013] Preferably, the left and right ends of the permanent magnet are respectively equipped with a left pole piece and a right pole piece, and the two ends of the magnetic ring are respectively against the magnetic conductive ring and the right pole piece. The left pole piece and the right pole piece are tightly attached to the axial ends of the permanent magnet, which can concentrate the magnetic flux lines emitted by the permanent magnet into the gap formed by the magnetic cup and the magnetic conductive ring, and can also block the magnetic field coupling between the permanent magnet and external metal parts (such as speaker housing, vehicle-mounted metal frame).

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The new design structure uses a shared permanent magnet for both the left and right speaker assemblies, eliminating the additional permanent magnets and supporting magnetic circuit components found in traditional dual-speaker solutions. The left and right speaker assemblies each emit sound in two directions, covering the front, back, or left and right directions within the vehicle. When the dual diaphragms operate simultaneously, the total air displacement area is twice that of a single diaphragm. Combined with the coordinated vibration of the dual voice coils, air displacement is significantly increased. The symmetrical structure of the left and right speaker assemblies vibrates in opposite directions, offsetting some harmful vibrations.

[0016] The permanent magnet adopts a segmented structure, realizing N→S and S→N reverse magnetic fields in a single integrated permanent magnet. This achieves stable output of reverse magnetic fields on a single permanent magnet, eliminating the need for additional magnets while improving magnetic field efficiency and resolving the technical prejudice that a single permanent magnet cannot provide reverse magnetic fields.

[0017] The left and right voice coils adopt differently designed structures. Through the differentiated arrangement of multi-layer wire groups and wire coils, the inductance of the left voice coil is made smaller than that of the right voice coil. This forms a dynamic match with the characteristic that the right voice coil is heavier than the left voice coil, further suppressing the mutual inductance fluctuations caused by vibration coupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 It is a main cross-sectional structural diagram of the present invention;

[0020] Figure 3 It is a structural diagram of the permanent magnet of the present invention;

[0021] Figure 4 2 is a structural diagram of the left voice coil and the right voice coil of the present invention.

[0022] Reference numerals:

[0023] 1. Magnetic ring, 11. Second gap, 12. First gap, 13. Right elastic wave, 14. Left elastic wave, 15. Dust cover, 16. Left basin, 17. Left diaphragm, 18. Foam gasket, 2. Magnetic ring, 3. Left voice coil, 31. Tubular hollow skeleton, 32. Multi-layer wire group, 4. Right voice coil, 41. Wire coil, 42. Tubular skeleton, 43. Solid part, 5. Left pole piece, 6. Right diaphragm, 7. Right basin, 8. Right pole piece, 9. Permanent magnet, 91. Right section permanent magnet, 92. Left section permanent magnet, 93. Tapered side, 94. Middle isolation layer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] In existing technologies, if traditional in-vehicle audio systems need to cover the front and rear sound fields, independent speakers usually need to be installed at the front and rear of the vehicle (such as 1-2 units for the front door and 1-2 units for the rear door). Each speaker contains core components such as permanent magnets and magnetic circuit components, resulting in a large total installation space (especially in the cabin of new energy vehicles, where space is further compressed by batteries and electronic control systems). The multi-magnet structure also increases the weight of the vehicle (a single permanent magnet weighs about 50-100g, and a dual unit adds 100-200g). New energy vehicles now generally have more than 15 speakers, so the overall multi-magnet structure is relatively heavy, which will affect battery life or fuel economy.

[0026] The amount of air displaced by a traditional single-diaphragm speaker is limited by the diaphragm's area and amplitude (in automotive environments, the diaphragm diameter is typically ≤10cm). Low-frequency signals (e.g., below 60Hz) require a large volume of air to effectively reproduce them. However, the limited air displacement of a single diaphragm results in insufficient bass depth (typically stopping at 80Hz) and a narrow dynamic range (≤80dB), making it difficult to reproduce low-frequency details such as drums and bass in music. If two independent speakers are used in conjunction, the resonant frequencies of their vibration systems (voice coil, damper, and diaphragm) may differ, causing mutual vibration interference and increasing total harmonic distortion (THD) to over 1%. Especially at high volumes, this distortion can mask musical details and affect the purity of the sound quality.

[0027] In order to solve the above problems, Figure 1-4As shown, the present invention provides a positive and negative air-propelled dual-diaphragm car audio system, comprising a permanent magnet 9, a magnetic ring 2 is coaxially mounted on the radial outer side of the permanent magnet 9, a magnetic conductive ring 1 is coaxially mounted on the radial outer side of the magnetic ring 2, a first gap 12 opening toward the axial left end of the permanent magnet 9 is provided between the permanent magnet 9 and the magnetic ring 2, a second gap 11 opening toward the axial right end of the permanent magnet 9 is provided between the magnetic ring 2 and the magnetic conductive ring 1, a left speaker assembly and a right speaker assembly are respectively mounted on the axial left end and the axial right end of the magnetic conductive ring 1, the left voice coil 3 in the left speaker assembly extends into the first gap 12, and the right voice coil 4 in the right speaker assembly extends into the second gap 11, the permanent magnet 9 comprises a left segment permanent magnet 92 matching the left voice coil 3, a right segment permanent magnet 91 matching the right voice coil 4, and a second segment permanent magnet 91 located between the left voice coil 3 and the right voice coil 4. The middle isolation layer 94, the left end face of the left section permanent magnet 92 is the N pole, and the right end face is the S pole, the left end face of the right section permanent magnet 91 is the S pole, and the right end face is the N pole. The design of the left speaker component and the right speaker component sharing a permanent magnet eliminates the extra permanent magnets and supporting magnetic circuit components in the traditional dual-speaker solution. The left speaker component and the right speaker component emit sound to both sides respectively, which can cover the front and back or left and right directions in the car. When the dual sound membranes work at the same time, the total air pushing area is twice that of the single sound membrane. With the coordinated vibration of the dual voice coils, the air displacement is significantly increased. The left and right speaker components adopt a symmetrical structural design with opposite vibration directions, which can offset some harmful vibrations. The permanent magnet 9 adopts a segmented structure to realize N→S and S→N reverse magnetic fields in a single integrated permanent magnet, and realizes stable output of reverse magnetic fields on a single permanent magnet, eliminating additional magnets while improving magnetic field efficiency.

[0028] Specifically, the magnetic ring 1 can adopt a split structure, and after assembly, the cross-section is "I-shaped", which is conducive to the fixed connection of its axial ends to the left speaker assembly and the right speaker assembly respectively. The magnetic ring 2 is arranged inside the magnetic ring 1. In order to facilitate the formation of the first gap 12 and the second gap 11, the axial left end of the magnetic ring 2 is provided with a radially outward first step, and the axial right end of the magnetic ring 2 is provided with a radially inward second step, so the first step is used to form the second gap 11, and the second step is used to form the first gap 12. This structure is more compact and reasonable, and maximizes the use of the radial space of the audio.

[0029] In this embodiment, the left permanent magnet 92 is made of a high-performance neodymium iron boron alloy, with an axial length L1 of 15 mm and a diameter D of 20 mm. The right permanent magnet 91 is also made of N52 neodymium iron boron alloy, with an axial length L2 of 15 mm and the same diameter as the left permanent magnet 92. When the two permanent magnets are coaxially docked, the total length L is 30 mm, and the diameter remains 20 mm, making them suitable for the compact installation space of the vehicle speaker. The intermediate isolation layer 94 is a polyimide film with a thickness of no more than 0.1 mm. The intermediate isolation layer 94 prevents magnetic field short circuits caused by direct contact between the two permanent magnets, and also buffers magnetic field interference during magnetization, ensuring a clear boundary between the two magnetization directions. The thickness of the intermediate isolation layer 94 is less than 0.1 mm to avoid affecting the continuity of the magnetic field. The two permanent magnets are bonded to the intermediate isolation layer 94 using epoxy resin glue (model E-51), with a bond strength of ≥ 20 MPa and a thickness of less than 0.05 mm.

[0030] In this embodiment, the right end face of the left-segment permanent magnet 92 and the left end face of the right-segment permanent magnet 91 are both provided with a tapered side portion 93, so that the docking area of ​​the left-segment permanent magnet 92 and the right-segment permanent magnet 91 forms a V-shaped magnetic field transition zone. This structure can reduce the sudden change of the magnetic field at the boundary, and reduce the rate of change of the magnetic field intensity between the first gap and the second gap from 20% / mm in the traditional right-angle docking to 5% / mm, thereby improving the stability of the force on the voice coil. Through the tapered transition design, the continuity of the magnetic field at the boundary between the two sections is improved. Specifically, the taper of the tapered side portion 93 is 3°, and the end of the tapered side portion 93 is chamfered with 0.5mm×45° to avoid the magnetic field being concentrated at the corners and generating leakage magnetic flux.

[0031] In the traditional single-magnet structure, when the dual voice coils move in opposite directions, one voice coil is always in the inefficient magnetic field area. However, in the technical solution of this embodiment, the radial magnetic field strength B1=0.96T at the first gap 12, and the radial magnetic field strength B2=1.44T at the second gap 11, are both in the efficient force range. In addition, through the tapered transition design, the continuity of the magnetic field at the boundary between the two sections is improved, and the electromagnetic force fluctuation during the movement of the left and right voice coils is reduced from ±15% to ±5%, and the total harmonic distortion (THD) is reduced from 1% to 0.3%.

[0032] In this embodiment, as a specific structure of the left voice coil 3, as shown in FIG. Figure 4As shown, the left voice coil 3 includes a tubular hollow skeleton 31 and a plurality of multi-layer wire groups 32 wound around the right end of the tubular hollow skeleton 31. The right voice coil 4 includes a tubular skeleton 42. The left end of the tubular skeleton 42 is provided with a single-layer sparsely wound wire coil 41. The right end of the tubular skeleton 42 is provided with a solid portion 43. The weight of the right voice coil 4 is greater than that of the left voice coil 3. The different arrangement of the multi-layer wire group 32 and the wire coil 41 makes the inductance of the left voice coil 3 smaller than that of the right voice coil 4, forming a dynamic match with the characteristic that the weight of the right voice coil 4 is greater than that of the left voice coil 3, further suppressing the mutual inductance fluctuation caused by vibration coupling.

[0033] Specifically, the multilayer conductor assemblies 32 utilize high-purity oxygen-free copper wire. Four multilayer conductor assemblies 32 are arranged axially side by side, each wound with 30 turns, for a total of 120 turns. 0.01mm thick polyimide film is used as insulation between the multilayer conductor assemblies 32. The winding tension is controlled at 5g±1g to ensure a tight fit of the coils, maintaining a stable inductance L1 of 0.5mH±0.02mH. The winding direction is clockwise when viewed from the top of the left voice coil 3. This, combined with the radially outward magnetic field of the first gap 12, generates an axial forward driving force when current is applied.

[0034] The wire coil 41 is made of silver-plated oxygen-free copper wire. The wire diameter of the wire coil 41 on the right voice coil 4 is larger than that of the multilayer wire assembly 32 on the left voice coil 3, specifically 0.2 mm in diameter, allowing it to carry a higher current. The wire coil 41 has a total of 50 turns, and the pitch of the winding spiral gradually increases from the left end to the right end. This structural arrangement can accommodate axial displacement differences during low-frequency vibration. The winding tension is controlled at 15g ± 2g, ensuring a close fit between the coil and the tubular bobbin 42 while leaving enough room for vibration. Its inductance L2 is stabilized at 1.0mH ± 0.05mH. The winding direction is counterclockwise when viewed from the top of the right voice coil 4. This, in conjunction with the radially inward magnetic field of the second gap 11, generates an axially backward driving force when current is applied.

[0035] Therefore, the weight ratio of the left voice coil 3 and the right voice coil 4 is 1:2, so that when the right voice coil 4 moves in the reverse direction, its inertia can offset part of the vibration, and it can also match the inductance ratio between the left voice coil 3 and the right voice coil 4.

[0036] Specifically, the tubular hollow skeleton 31 is made of a polyimide tube, and a 0.05mm thick graphene thermal conductive coating (thermal conductivity 500W / m·K) can be sprayed on the inner wall of the tubular hollow skeleton 31. This can quickly transfer the heat of the left voice coil 3 during operation to the magnetic cup for heat dissipation; three axial guide grooves can also be opened on the outer wall to form an air flow channel in conjunction with the magnetic circuit ventilation holes, thereby improving the heat dissipation efficiency by 40%.

[0037] The tubular skeleton 42 and the solid portion 43 are made of 6061-T6 aluminum alloy. A 0.1 mm deep spiral groove is made on the outer surface of the tubular skeleton 42 to match the winding direction of the wire coil 41. The wire is embedded in the groove to achieve mechanical positioning to prevent loosening.

[0038] When the two voice coils move in opposite directions, electromagnetic induction causes the current change in the left voice coil to generate a mutual electromotive force in the right voice coil. In conventional structures, this mutual electromotive force can cause signal distortion (total harmonic distortion (THD)) by increasing to 1.2%. However, with the technical solution described above, the tubular bobbin 42 of the right voice coil 4, when moving in opposite directions, cuts through the alternating magnetic field generated by the left voice coil 3, inducing eddy currents in the opposite direction of the current flow in the left voice coil. The magnetic field generated by these eddy currents is in the opposite direction of the mutual induction field, creating a "reverse cancellation" effect, reducing the mutual inductance from 0.3mH to 0.05mH.

[0039] At the same time, the inductance L1 of the left voice coil 3 is 0.5mH and the inductance L2 of the right voice coil 4 is 1.0mH, with an inductance ratio of 1:2, which forms a dynamic match with the mass ratio of the dual voice coils of 1:2, further suppressing the mutual inductance fluctuations caused by vibration coupling.

[0040] In this embodiment, the left speaker assembly also includes a left basin frame 16 connected to the axial left end of the magnetic ring 1, and the left basin frame 16 is equipped with a left elastic wave 14 and a left sound membrane 17 connected to the left voice coil 3. The right speaker assembly also includes a right basin frame 7 connected to the axial right end of the magnetic ring 1, and the right basin frame 7 is equipped with a right elastic wave 13 and a right sound membrane 6 connected to the right voice coil 4. It has a simple structure and is easy to install. The left sound membrane 17 and the right sound membrane 6 are oriented in opposite directions. At the same time, foam gaskets 18 are installed on the right side of the end face of the left basin frame 16 and the right side of the end face of the right basin frame 7, which can improve the vibration reduction effect of the entire audio installation. Dust covers 15 are installed in the middle of the left sound membrane 17 and the right sound membrane 6 to prevent external impurities from entering the left voice coil 3 and the right voice coil 4.

[0041] In this embodiment, the left and right ends of the permanent magnet 9 are respectively mounted with left and right pole pieces 5 and 8. The ends of the magnetic ring 2 abut against the magnetic ring 1 and right pole piece 8, respectively. The left and right pole pieces 5 and 8 are in close contact with the axial ends of the permanent magnet 9, concentrating the magnetic flux lines emitted by the permanent magnet into the gap formed by the magnetic cup and the magnetic ring. This also blocks magnetic field coupling between the permanent magnet and external metal components (such as the speaker housing or the vehicle's metal frame). Specifically, without pole pieces, the magnetic flux lines at both ends of the permanent magnet diffuse randomly into space (with a magnetic flux leakage rate of approximately 30%). With the pole pieces installed, the magnetic flux lines are confined within the magnetic circuit through the magnetic conductivity of the pole pieces, increasing the magnetic field strength in the first and second gaps, for example, from 0.8 T to 1.0 T. This in turn enhances the electromagnetic force acting on the voice coil and improves the speaker's sensitivity.

[0042] Furthermore, the magnetic field distribution of the permanent magnet 9 itself may exhibit axial non-uniformity. The pole piece, through its inherent reluctance properties, creates a smooth magnetic field gradient. For example, the left pole piece 5 can reduce the deviation in the radial component distribution of the magnetic field in the first gap 12 from ±5% to ±2%, while the right pole piece 8 simultaneously optimizes the magnetic field uniformity in the second gap 11. This improved magnetic field uniformity reduces force fluctuations during voice coil vibration, thereby reducing nonlinear distortion.

[0043] As a specific embodiment 1 of the dual-tone membrane car audio in this embodiment:

[0044] Designed for the interior of the front door trim of a certain pure electric SUV, the system has a reserved installation space of 120mm × 80mm × 60mm. The left speaker assembly faces the interior of the cockpit, toward the driver's ears, while the right speaker assembly faces the exterior of the door, toward the door panel cavity. The left and right booms (16, 7) are connected to the metal frame of the interior trim panel with M4 screws. The foam gaskets (18) on the boom ends are compressed to a minimum of 0.5mm to provide a vibration-damping seal and prevent vibration transmission to the vehicle body and unwanted noise. Based on the front door cavity volume (approximately 5L), the left sound diaphragm (17) uses a 100mm diameter composite paper pulp membrane (rigidity modulus 2.5GPa), while the right sound diaphragm (6) uses a 100mm diameter butyl rubber composite membrane (damping coefficient 0.3) to accommodate the low-frequency resonance characteristics of the door.

[0045] The left voice coil 3 receives high-frequency signals of 2kHz-20kHz. Through the dense winding design of the multi-layer wire group 32, the high-frequency directivity is controlled within the range of ±30°, and the high-frequency sound pressure level at the driver's ear reaches 85dB; the right voice coil 4 receives intermediate-frequency signals of 20Hz-2kHz. The eddy current effect of the tubular skeleton 42 reduces the mutual inductance distortion in the 500Hz frequency band from 0.8% to 0.2%.

[0046] When the dual diaphragms work together, they push air at a rate of 0.8 L / s, boosting the 60Hz low-frequency sound pressure level by 6dB. The door cavity resonance is effectively utilized, extending the bass down to 45Hz. The overall installation volume is 85 cm³, compared to 150 cm³ for a traditional dual-speaker solution, and the weight is 120 g, compared to 220 g for a traditional solution. This reduces the door's overhang load and extends hinge life.

[0047] As a specific embodiment 2 of the dual-tone membrane car audio in this embodiment:

[0048] Installation Location: The dual-diaphragm car audio system is embedded beneath the center console's central storage compartment, with the left speaker assembly facing the driver and the right speaker assembly facing the front passenger seat, achieving symmetrical sound coverage for the front seats. Designed for the metallic center console environment, the left and right pole pieces 5 and 8 utilize a laminated structure of 3mm-thick silicon steel sheets, improving magnetic shielding effectiveness by 20dB and preventing interference with the vehicle's navigation signal.

[0049] The 1:2 weight ratio of the left and right voice coils reduces the 1kHz mid-frequency total harmonic distortion (THD) to 0.3%. The V-shaped magnetic field transition zone ensures that the change rate of the magnetic field strength of the left and right voice coils is ≤5% / mm, the 2kHz signal phase difference is controlled at ±5°, and the stereo image positioning error in the center of the front row is ≤5cm.

[0050] As a specific embodiment 3 of the dual-tone membrane car audio in this embodiment:

[0051] Installation Location: The dual-diaphragm car audio system is integrated on both sides of the rear roof armrest. The left speaker assembly points forward toward the second-row passengers, and the right speaker assembly points rearward toward the third-row passengers, covering the entire rear area of ​​the seven-seat vehicle. The diameter of the right voice coil's four wires has been increased to 0.25mm, and the current carrying capacity has been increased to 2A to accommodate the high volume requirements of the rear seats. The solid 43 aluminum frame has been increased to 2mm in thickness to enhance eddy current compensation capabilities.

[0052] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0053] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being described. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0054] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0055] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A positive and negative air-driven dual-diaphragm car audio system, comprising a permanent magnet (9), a magnetic ring (2) coaxially mounted radially outwardly of the permanent magnet (9), and a magnetic conductive ring (1) coaxially mounted radially outwardly of the magnetic ring (2), characterized in that: A first gap (12) opening toward the axial left end of the permanent magnet (9) is provided between the permanent magnet (9) and the magnetic ring (2), and a second gap (11) opening toward the axial right end of the permanent magnet (9) is provided between the magnetic ring (2) and the magnetic conductive ring (1). A left speaker assembly and a right speaker assembly are respectively installed at the axial left end and the axial right end of the magnetic conductive ring (1). The left voice coil (3) in the left speaker assembly extends into the first gap (12), and the right voice coil (3) in the left voice coil extends into the first gap (12). The right voice coil (4) in the speaker assembly extends into the second gap (11), and the permanent magnet (9) includes a left section permanent magnet (92) matching the left voice coil (3), a right section permanent magnet (91) matching the right voice coil (4), and an intermediate isolation layer (94) located between the left voice coil (3) and the right voice coil (4). The left end face of the left section permanent magnet (92) is an N pole, and the right end face is an S pole. The left end face of the right section permanent magnet (91) is an S pole, and the right end face is an N pole.

2. The positive and negative air-driven dual-diaphragm car audio system according to claim 1, characterized in that: The right end surface of the left permanent magnet (92) and the left end surface of the right permanent magnet (91) are both provided with a tapered side portion (93), so that the butt joint area of ​​the left permanent magnet (92) and the right permanent magnet (91) forms a V-shaped magnetic field transition zone.

3. The positive and negative air-driven dual-diaphragm car audio system according to claim 1, characterized in that: The intermediate isolation layer (94) is a polyimide film with a thickness not greater than 0.1 mm.

4. The positive and negative air-driven dual-diaphragm car audio system according to claim 1, characterized in that: The left voice coil (3) includes a tubular hollow frame (31) and a plurality of multi-layer wire groups (32) wound around the right end of the tubular hollow frame (31). The right voice coil (4) includes a tubular frame (42). The left end of the tubular frame (42) is provided with a single-layer sparsely wound wire coil (41). The right end of the tubular frame (42) is provided with a solid portion (43). The weight of the right voice coil (4) is greater than that of the left voice coil (3).

5. The positive and negative air-driven dual-diaphragm car audio system according to claim 4, characterized in that: The weight ratio of the left voice coil (3) to the right voice coil (4) is 1:

2.

6. The positive and negative air-driven dual-diaphragm car audio system according to claim 4, characterized in that: The wire diameter of the wire coil (41) on the right voice coil (4) is greater than the wire diameter of the multilayer wire group (32) on the left voice coil (3), and the winding spiral pitch of the wire coil (41) gradually increases from the left end to the right end.

7. The positive and negative air-driven dual-diaphragm car audio system according to claim 1, characterized in that: The left speaker assembly further comprises a left basin frame (16) connected to the axial left end of the magnetic ring (1), wherein the left basin frame (16) is provided with a left elastic wave (14) and a left sound membrane (17) connected to the left voice coil (3), and the right speaker assembly further comprises a right basin frame (7) connected to the axial right end of the magnetic ring (1), wherein the right basin frame (7) is provided with a right elastic wave (13) and a right sound membrane (6) connected to the right voice coil (4).

8. The positive and negative air-driven dual-diaphragm car audio system according to claim 7, characterized in that: A foam gasket (18) is installed on the right side of the end surface of the left basin rack (16) and the right side of the end surface of the right basin rack (7).

9. The positive and negative air-driven dual-diaphragm car audio system according to claim 7, characterized in that: Dust covers (15) are installed in the middle of the left sound diaphragm (17) and the right sound diaphragm (6).

10. The positive and negative air-driven dual-diaphragm car audio system according to any one of claims 1 to 9, characterized in that: The left end and right end of the permanent magnet (9) are respectively mounted with a left pole piece (5) and a right pole piece (8), and the two ends of the magnetic ring (2) are respectively against the magnetic conductive ring (1) and the right pole piece (8).

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