Phase plug, vibration unit and sound generating device

Abstract

The present invention provides a phase plug, a vibration unit and a sound-generating device, the phase plug comprising: a phase plug central axis and a plurality of fins; one end of the phase plug central axis is a first cone, and the other end is a second cone; the bottoms of the two cones are completely aligned and connected, and the height of the first cone is greater than that of the second cone; the top of the second cone is used to bond to the middle of the sound film that matches the taper; each fin is erected on the side of the first cone, and all coincide with its axial section; each fin comprises a plurality of side edges, the first side edge is arranged along the side of the first cone, and the second side edge of each fin is extended along one side of the cross section of the second cone, the contour formed is in the shape of a truncated cone side and is on the same cone surface as the side of the second cone, and the third side edge can extend and converge at a point to form a contour surrounding the side of the first cone; the angles between two adjacent fins are all set angles. Through the above scheme, the problem of sound wave cancellation can be solved and the sound pressure level can be improved.

Description

Technical Field

[0001] The present invention relates to the field of acoustic technology, and in particular to a phase plug, a vibration unit and a sound-generating device. Background Art

[0002] In the prior art, the realization of high sound pressure level sound wave devices is to carry out different designs according to different acoustic index requirements. Each product has to undergo great changes and a long time to be completed, which is time-consuming, labor-intensive and costly. Often, after a product is designed, if new indicators are required, a new design must be carried out. At the same time, given the limitation of spatial flexibility, it is also difficult to design a large integrated device to achieve high-efficiency and high sound pressure level acoustic equipment. Moreover, it is difficult to maintain and upgrade each device with different indicators in a unified manner, and the sustainable performance improvement between each other is very poor. High-efficiency acoustic equipment is increasingly valued in today's security, but the technical bottleneck is difficult to break through. The sound pressure level has reached its peak and it is difficult to increase it, resulting in the delay in large-scale application of acoustic energy equipment.

[0003] Moreover, with the progress of society, a large number of social management and security management require intelligent automatic sound playback and long-distance sound prompts to convey prompt sounds intelligently, long-distance and efficiently. Traditional speaker technology cannot produce enough physiological stimulation of human hearing, making it difficult for people to hear the various required sound instructions. A new technical method is needed to solve this problem of making it easier for people to hear. Many sound deterrent devices are made of magnetic speakers. At the same frequency, the stimulation to human hearing is insufficient, and new technologies are needed to make it easier for people to hear auditory stimulation effects.

[0004] Therefore, in the prior art, solving the problem of sound wave cancellation and improving the sound pressure level are issues to be solved. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a phase plug, a vibration unit and a sound-generating device to eliminate or improve the problem of sound wave cancellation occurring during the superposition process of sound waves in the prior art.

[0006] The technical solution of the present invention is as follows:

[0007] According to one aspect of an embodiment of the present invention, there is provided a phase plug, comprising a phase plug central axis portion and a plurality of ribs;

[0008] One end of the central axis of the phase plug is in the shape of a first cone, and the other end is in the shape of a second cone; the bottom of the first cone is completely aligned with and connected to the bottom of the second cone, and the height of the first cone is greater than the height of the second cone; the top of the second cone is used to bond the middle part of the sound film that can match the second cone in taper;

[0009] The multiple fins are erected on the side of the first cone, and the planes where the fins are located coincide with the axial section of the first cone; each of the fins includes a first side, a second side and a third side, the first side of the fin is arranged along the side of the first cone, the second side of each fin is extended along one side of the cross section of the second cone, the contour formed by the second sides of all the fins is in the shape of a truncated cone side and is on the same conical surface as the side of the second cone, and the third sides of all the fins can extend and converge at one point to form a conical contour surrounding the side of the first cone; the angles between the planes where two adjacent fins are located are all set angles.

[0010] In some embodiments, the angle between the planes where two adjacent fins are located ranges from 12 degrees to 18 degrees.

[0011] In some embodiments, the taper angle of the first cone ranges from 10 degrees to 16 degrees.

[0012] In some embodiments, the point where the third sides of all fins extend and converge is located near the vertex of the first cone.

[0013] In some embodiments, the frequency range of the sound in the frequency range sensitive to human ears is 3.5 kHz to 3.7 kHz.

[0014] According to another aspect of the embodiments of the present invention, there is provided a vibration unit, such as the phase plug, short horn, piezoelectric ceramic sheet, sound membrane and resonance sound-generating cavity for generating sound in the frequency band sensitive to human ears as described in any of the above embodiments;

[0015] The short horn includes a sound wave constraint part and a peripheral part; the sound wave constraint part includes a contraction part and a cylindrical part, and the thinner end of the contraction part is connected to one end of the cylindrical part to form a funnel shape; the inner circumference of the contraction part is arranged around the outside of the third side of all the fins of the phase plug to form a sound wave transmission channel between every two adjacent fins; the peripheral part is arranged around the periphery of the sound wave constraint part to cooperate with the resonance sound cavity to form a resonance sound cavity for accommodating the phase plug, the sound membrane and the piezoelectric ceramic piece; the top of the second cone of the phase plug is bonded to the middle of one side of the sound membrane; the other side of the sound membrane is bonded to the middle of one side of the ceramic surface of the piezoelectric ceramic piece.

[0016] In some embodiments, the piezoelectric ceramic sheet includes a first piezoelectric ceramic diaphragm, a second piezoelectric ceramic diaphragm, and a metal sheet; the first piezoelectric ceramic diaphragm and the second piezoelectric ceramic sheet are symmetrically bonded to two sides of the metal sheet.

[0017] In some embodiments, the vibration unit further comprises:

[0018] A silicone pad is arranged between the peripheral edge of the outer portion of the short horn and the sound membrane.

[0019] In some embodiments, the thickness of the silicone pad ranges from 1.5 mm to 3 mm.

[0020] In some embodiments, the sound membrane is a paper sound membrane, and the mass of the paper sound membrane is 0.2g±5%.

[0021] In some embodiments, the volume range of the resonance sound cavity is 31cm 3 ~35cm 3 .

[0022] In some embodiments, the diameter of the piezoelectric ceramic diaphragm ranges from 26.55 mm to 37.55 mm, and the diameter of the metal sheet ranges from 28 mm to 39 mm, wherein the diameter of the piezoelectric ceramic diaphragm is smaller than the diameter of the metal sheet;

[0023] The thickness of the piezoelectric ceramic diaphragm ranges from 285μm to 315μm, and the thickness of the metal sheet ranges from 190μm to 210μm; the piezoelectric ceramic diaphragm includes oxygen, titanium, zirconium, lead, strontium and niobium, wherein the content of strontium ranges from 3.56% to 3.94%, and the content of niobium ranges from 5.38% to 5.95%.

[0024] According to another aspect of an embodiment of the present invention, a sound-generating device is provided, comprising: a vibration unit and a horn unit for generating sound in a frequency band sensitive to human ears as described in any of the above embodiments; the horn unit comprises a sound wave superposition outlet tube and at least one pair of sound wave introduction tubes; each pair of sound wave introduction tubes comprises a first sound wave introduction tube and a second sound wave introduction tube; the first sound wave introduction tube, the second sound wave introduction tube and the sound wave superposition outlet tube all comprise a first trapezoidal side surface and a second trapezoidal side surface arranged in parallel and a first square side surface and a second square side surface arranged oppositely, and the cross sections of the three are all squares that gradually increase in size along the sound wave conduction direction;

[0025] The end of the first sound wave introduction tube with a smaller cross section is formed by a transition from a square cross section to a first circular sound emission port; the end of the second sound wave introduction tube with a smaller cross section is formed by a transition from a square cross section to a second circular sound emission port; the end of the sound wave superposition export tube with a larger cross section is formed with a square sound outlet port; the end of the first sound wave introduction tube with a larger cross section and the end of the second sound wave introduction tube with a larger cross section are both connected to the end of the sound wave superposition export tube with a smaller cross section, and the first trapezoidal side surface of the first sound wave introduction tube and the first trapezoidal side surface of the second sound wave introduction tube are adjacent to form a V-shaped groove, and the second trapezoidal side surface of the first sound wave introduction tube and the second trapezoidal side surface of the second sound wave introduction tube are adjacent to the first square side surface and the second square side surface of the sound wave superposition export tube respectively, so that the same two sound wave signals are respectively transmitted from the first circular sound emission port into the first sound wave introduction tube and from the second circular sound emission port into the second sound wave introduction tube, and then superimposed in the sound wave superposition export tube and the superimposed and enhanced sound wave signals are transmitted from the square sound outlet; wherein, each first circular sound emission port and each second circular sound emission port of the horn unit is respectively equipped with a vibration unit.

[0026] A phase plug, a vibration unit, and a sound-generating device according to an embodiment of the present invention are designed accordingly for the phase plug, and the traditional piezoelectric ceramics are modified around the acoustic effect reaction characteristics. According to the characteristics of the human ear sensitive frequency band, a targeted design is performed, and the volume and cluster design of the characteristic frequency of the sound-generating cavity are modified. A comprehensive modification is performed around the 3.4K-3.8K Hz that the human ear is sensitive to, so that the sound can be heard more sensitively and stimulatingly, and the transmission directionality of the sound wave and the anti-interference performance are improved.

[0027] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically pointed out in the written description, claims, and drawings.

[0028] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are only for illustrating the principles of the present invention. In order to facilitate the illustration and description of some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other components in the exemplary device actually manufactured according to the present invention. In the drawings:

[0030] Figure 1 A schematic diagram of the structure of a phase plug according to an embodiment of the present invention;

[0031] Figure 2 A schematic structural diagram of a second cone of a phase plug according to an embodiment of the present invention;

[0032] Figure 3 A top view of a short horn according to an embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of the bottom structure of a short horn according to an embodiment of the present invention;

[0034] Figure 5 It is a structural schematic diagram of a resonance sound-generating cavity according to an embodiment of the present invention;

[0035] Figure 6 It is a structural schematic diagram of a horn unit according to an embodiment of the present invention;

[0036] Figure 7 FIG. 4 is a frequency response curve of a sound generating device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0038] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0039] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0040] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0042] Figure 1 FIG. 1 is a schematic diagram of the structure of a phase plug according to an embodiment of the present invention. Figure 1 As shown, the phase plug for generating sound in a frequency band sensitive to human ears comprises a phase plug central axis portion 10 and a plurality of ribs 20 .

[0043] One end of the central axis 10 of the phase plug is in the shape of a first cone 11, and the other end is in the shape of a second cone; the bottom of the first cone 11 is completely aligned with and connected to the bottom of the second cone, and the height of the first cone 11 is greater than the height of the second cone; the top of the second cone is used to bond the middle part of the sound film that can match the second cone in taper; the multiple fins 20 are vertically arranged on the side of the first cone 11, and the plane where each of the fins 20 is located coincides with the axial section of the first cone 11; each of the fins includes The ribs include a first side, a second side 21 and a third side 22, the first side of the rib is arranged along the side of the first cone 11, the second side 21 of each rib is extended along one side of the cross section of the second cone, the contour formed by the second side 21 of all the ribs is in the shape of a truncated cone side and is on the same conical surface as the side of the second cone, and the third side 22 of all the ribs can extend and converge at one point to form a conical contour surrounding the side of the first cone 11; the angles between the planes where two adjacent ribs are located are all set angles.

[0044] Among them, since the bases of the two cones in the central axis of the phase plug are completely aligned and connected, the height of the first cone is greater than that of the second cone. Figure 2 FIG. 1 is a schematic diagram of the structure of the second cone according to an embodiment of the present invention. Figure 2 As shown, the taper of the second cone is related to the sound film bonded to the taper of the second cone; therefore, the taper of the first cone is related to the first cone. The multiple fins of the phase plug are evenly spaced so that the sound waves can be squeezed and transmitted from between the fins. The convergence point of the extension lines of each fin can also coincide with the cone angle of the first cone. The sound waves are guided by the fins, so that the sound waves are converged to the cone head, and the squeezing of the sound waves between the fins can increase the sound pressure level of the sound waves. In addition to squeezing and propagating the sound waves through the fins, a sound wave channel can also be set using a prism. For example, the ribs of the phase plug used to form the sound wave channel can be in the shape of a quadrangular prism, with one end connected to the second cone being a first rectangle, and the other end connected to the first cone being a second rectangle, the first rectangle being parallel to the second rectangle, and the shape of the surface opposite to the central body being a trapezoid, the upper base of the trapezoid coinciding with the wide side of the second rectangle, and the lower base coinciding with the wide side of the first rectangle, and the extension of the perpendicular bisector of the trapezoid converging at the vertex of the cone angle of the first cone.

[0045] In some embodiments, the angle between the planes where two adjacent fins are located ranges from 12 degrees to 18 degrees.

[0046] The angle between the planes where two adjacent fins are located can be 12 degrees, 13 degrees, 14 degrees, 15 degrees, 16 degrees, 17 degrees or 18 degrees, etc. For example, the angle between the planes where two adjacent fins are located is 18 degrees. The angle between two adjacent fins is related to the frequency of the sound wave. The higher the frequency of the sound wave, the smaller the angle of the fins of the phase plug.

[0047] In some embodiments, the taper range of the first cone is 10 degrees to 16 degrees. Among them, the taper range of the phase plug is a set taper range that can reflect sound waves in the frequency band sensitive to human ears and superimpose them in phase. The taper is related to the taper of the second cone. The taper of the first cone can be 10 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees, 15 degrees or 16 degrees or other angles. For example, the taper of the first cone is 10 degrees. Therefore, under the set taper, the superposition effect of sound waves can be optimal and the loss is minimized.

[0048] In some embodiments, the point where the third sides of all fins extend and converge is located near the vertex of the first cone.

[0049] The extended convergence point may coincide with the vertex of the first cone, or may be below the vertex of the first cone, or may be above the vertex of the first cone, but the distance between the point and the vertex of the first cone may not exceed a set distance. The set distance may be set according to actual conditions.

[0050] In some embodiments, the frequency range of the sound in the frequency range sensitive to human ears is 3.5 kHz to 3.7 kHz.

[0051] The frequency range of human ear sensitive sound is 3.5kHz~3.7kHz, so the relevant acoustic equipment will stimulate the human ear when emitting sound in this frequency range. Therefore, in the actual use of phase plugs, if it is necessary to shock others, the purpose of shocking others can be achieved by using acoustic equipment that can produce sound in the frequency range of 3.5kHz~3.7kHz.

[0052] According to another aspect of an embodiment of the present invention, a vibration unit for producing sound in a frequency band sensitive to human ears is provided, such as the phase plug, short horn, piezoelectric ceramic diaphragm, sound membrane and resonance sound cavity for producing sound in a frequency band sensitive to human ears as described in any of the above embodiments.

[0053] Figure 3 FIG. 1 is a top view of a short horn according to an embodiment of the present invention. Figure 3As shown, the short horn includes a sound wave constraint part and a peripheral part; the sound wave constraint part includes a contraction part and a cylindrical part, and the thinner end of the contraction part is connected to one end of the cylindrical part to form a funnel shape; the inner circumference of the contraction part is arranged around the outside of the third side of all the fins of the phase plug to form a sound wave transmission channel between every two adjacent fins; the peripheral part is arranged around the outer periphery of the sound wave constraint part to cooperate with the resonance sound cavity to form a resonance sound cavity for accommodating the phase plug, the sound membrane and the piezoelectric ceramic piece; the top of the second cone of the phase plug is bonded to the middle of one side of the sound membrane; the other side of the sound membrane is bonded to the middle of one side of the ceramic surface of the piezoelectric ceramic piece.

[0054] The angle between the side wall of the contraction portion and the central axis needs to be equal to the angle between the third side of the rib of the phase plug and the central axis, so that when the phase plug is placed in the short horn, the inner side wall of the contraction portion and the phase plug can fit tightly together, and in the process of transmitting sound waves, the sound waves will not be transmitted from other positions outside the sound wave transmission channel formed by the two. In addition, multiple grooves can be set on the inner side wall, and fixings can be set on the outer side of the phase plug, so that the grooves on the inner side wall can be combined with the fixings of the phase plug to achieve the purpose of fixing the phase plug. A groove for fixing the silicone pad is set on the outer periphery of one end of the short horn into which the phase plug is placed. The end of the short horn combined with the resonant sound cavity can be tightly joined together so that the sound waves will not propagate outward from the joint between the two. Figure 4 The bottom structure schematic diagram of the short horn of one embodiment of the present invention. As shown in Figure 4, the constraint of the sound wave output port of the short horn pushes the air to transmit the sound wave and push the air to emit outward; and in the formed space, the piezoelectric ceramic sheet, the sound film, the silicone pad and the phase plug are accommodated. The short horn increases the compression ratio by reducing the area of ​​the unit radiation outlet of the sound wave, increasing the number of the sound wave radiation outlets, and constraining the angle of the sound wave radiation, thereby achieving the purpose of increasing the sound pressure level. The vibration unit can ensure that the energy of the sound wave can be radiated directly, and the loss of the radiated energy is extremely low, and there will be no back and forth reverberation, thereby avoiding the time difference caused by the back and forth reverberation, because if there is a time difference, the sound waves in the process of sound wave superposition will not reach the peak at the same time, and the best effect of sound wave superposition cannot be achieved.

[0055] In some embodiments, the piezoelectric ceramic diaphragm includes a first piezoelectric ceramic diaphragm, a second piezoelectric ceramic diaphragm, and a metal sheet; the first piezoelectric ceramic diaphragm and the second piezoelectric ceramic diaphragm are symmetrically bonded to two sides of the metal sheet.

[0056] The piezoelectric ceramic diaphragm includes two piezoelectric ceramic diaphragms and a metal sheet, one side of the metal sheet is bonded to the first piezoelectric ceramic diaphragm, and the other side of the metal sheet is bonded to the second piezoelectric ceramic diaphragm, and the first piezoelectric ceramic diaphragm and the second piezoelectric ceramic diaphragm are of the same size, and the bonding positions of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet on both sides of the metal sheet are symmetrical to each other, so as to generate a force that increases the energy of the sound wave. In addition, the mechanical quality factor is adjusted according to the alloy characteristics of the metal sheet, and the thickness of the piezoelectric ceramic sheet can also be adjusted according to the resistance impedance of the metal sheet.

[0057] In some embodiments, the vibration unit for generating sound in the frequency band sensitive to human ears further includes: a silicone pad, which is arranged between the peripheral edge of the outer portion of the short horn and the sound membrane. Among them, the voltage withstand characteristics of the piezoelectric ceramic diaphragm are improved to increase the sound pressure level of the sound, and the silicone pad of the right size can ensure that the piezoelectric ceramic diaphragm is within a safe and stable vibration amplitude range under high voltage working conditions. When the vibration unit is working, the sound membrane and the phase plug will come into contact, although there is a certain interval between the two, there will still be partial contact, and the change in the contact ratio will change the frequency characteristics, and the height of the silicone pad can determine the contact ratio between the sound membrane and the phase plug during operation.

[0058] In some embodiments, the thickness of the silicone pad ranges from 1.5 mm to 3 mm.

[0059] The thickness of the silicone pad can be 1.51mm, 1.53mm, 1.54mm, 1.55mm, 1.56mm, 1.58mm, 1.59mm, 2.11mm, 2.12mm, 2.30mm, 2.31mm, etc. When selecting the height of the silicone pad, it can be selected according to the actual required frequency characteristics to achieve the best effect of the required sound waves.

[0060] In some embodiments, the sound membrane is a paper sound membrane, and the mass of the paper sound membrane is 0.2g±5%.

[0061] Among them, the mass range of the paper sound film is 0.2g×(1-5%)~0.2g×(1+5%), that is, the mass range of the paper sound film is 0.19g~0.21g. For example, the mass of the paper sound film can be 0.191g, 0.193g, 0.195g, 0.197g, 0.199g, 0.201g or 0.203g, etc. In addition, since the elastic modulus, mass and compliance of the single characteristics can determine the distortion of the sound and the degree of frequency response; by comparing the elastic modulus, mass and compliance of PVC sound film, polymer sound film and paper sound film, it can be concluded that when the mass of the paper sound film is 0.2g±5%, the sound pressure level index is the highest when it is matched with the piezoelectric ceramic diaphragm to form a vibration unit. If ordinary sound film and other sound film are used, it can be found that the distortion of the restored human voice is high.

[0062] In some embodiments, the volume range of the resonance sound cavity is 31cm 3 ~35cm 3 .

[0063] in, Figure 5 FIG. 1 is a schematic diagram of the structure of a resonance sound-generating cavity in one embodiment of the present invention. Figure 5 As shown, the volume of the resonance sound cavity can be 31cm 3 、31.2cm 3 、31.4cm 3 、31.6cm 3 、31.8cm 3 、32cm 3 、32.1cm 3 、32.3cm 3 、32.5cm 3 、32.8cm 3 、33.1cm 3 、33.3cm 3 、33.5cm 3 、33.7cm 3 、33.9cm 3 、34.1cm 3 For example, the volume of the resonance cavity is 34.1cm 3 The maximum sound pressure level is achieved by adjusting the volume of the resonance sound cavity. The volume of the resonance sound cavity can be optimized by optimizing the cavity ratio to achieve the desired broadband, and the vibration of the sound wave is reflected through the cavity.

[0064] In some embodiments, the diameter of the piezoelectric ceramic diaphragm ranges from 26.55 mm to 37.55 mm, and the diameter of the metal sheet ranges from 28 mm to 39 mm, wherein the diameter of the piezoelectric ceramic diaphragm is smaller than the diameter of the metal sheet; the thickness of the piezoelectric ceramic diaphragm ranges from 285 μm to 315 μm, and the thickness of the metal sheet ranges from 190 μm to 210 μm; the piezoelectric ceramic diaphragm includes oxygen, titanium, zirconium, lead, strontium and niobium, wherein the content of strontium ranges from 3.56% to 3.94%, and the content of niobium ranges from 5.38% to 5.95%.

[0065] Among them, according to experimental research, it can be known that the sensitive frequency band for human ears is 3.4kHz to 3.8kHz. The first circular piezoelectric ceramic diaphragm and the second circular piezoelectric ceramic diaphragm are respectively pasted on both sides of the metal sheet, and the pasting positions and placement positions of the piezoelectric ceramic diaphragms on both sides overlap, so that during the vibration process, when the first circular piezoelectric ceramic diaphragm vibrates, the second circular piezoelectric ceramic diaphragm on the other side provides a force to the first circular piezoelectric ceramic diaphragm. Since the diameter of the piezoelectric ceramic diaphragm is smaller than the diameter of the metal sheet, the diameter of the piezoelectric ceramic diaphragm can be 26.55mm, 26.65mm, 26.75mm, 26.85mm, 26.95mm, 27.05mm, 27.15mm, 27.25mm, 27.35mm, 27.45mm, 29.50mm, 29.53mm, 29.55mm, 29.57mm, 29.61mm, 29.64mm, 29.66mm, 29.68mm, 29.78mm, 29.88mm, 29.98mm, 30.08mm or 30.18mm, etc. The diameter of the metal sheet can be 28.12mm, 28.22mm, 28.34mm, 28.45mm, 28.53mm, 28.55mm, 28.67mm, 28.79mm, 28.85mm, 29.15mm, 29.28mm, 31.56mm, 31.58mm, 31.60mm, 31.63mm, 31.67mm, 31.69mm, 31.71mm or 32.12mm, etc. Alternatively, the diameter of the piezoelectric ceramic diaphragm can be set to 29.75mm, 29.77mm, 29.79mm, 29.82mm, 29.84mm, 29.85mm, 29.88mm or 29.91mm; the diameter of the metal sheet can be set to 30.23mm, 30.25mm, 30.27mm, 30.30mm, 30.31mm, 30.33mm, 30.36mm, 30.38mm or 31.21mm, etc. The thickness of the piezoelectric ceramic diaphragm can be set to 285μm, 287μm, 289μm, 290μm, 291μm, 293μm, 296μm or 299μm, etc.; the thickness of the metal sheet can be set to 190μm, 191μm, 193μm, 194μm, 196μm, 198μm, 201μm or 203μm, etc.

[0066] By adjusting the content of each element in the piezoelectric ceramic diaphragm, it has higher toughness during use, can be used for a longer time and is not easy to break during use. The content of strontium element can be set to 3.56%, 3.57%, 3.59%, 3.61%, 3.63%, 3.66%, 3.68% or 3.70% and other contents, and the content of niobium element can be set to 5.38%, 5.40%, 5.41%, 5.43%, 5.46%, 5.48%, 5.51% or 5.53% and other contents. By adjusting the content of each element in the piezoelectric ceramic diaphragm, the ceramic grains can grow more evenly, and the resulting grains have fewer pores, good density, high conductivity efficiency, and thus, it can produce better sound stimulation.

[0067] For example, the diameter of the piezoelectric ceramic diaphragm is set to 29.53 mm, the diameter of the metal sheet is set to 31.58 mm, or the diameter of the piezoelectric ceramic diaphragm is set to 29.77 mm, and the diameter of the metal sheet is set to 31.21 mm. The thickness of the piezoelectric ceramic diaphragm is set to 289 μm, and the thickness of the metal sheet is set to 193 μm. The content of strontium in the piezoelectric ceramic diaphragm is set to 3.68%, and the content of niobium is set to 5.40%.

[0068] The toughness of the piezoelectric ceramic diaphragm is increased by adjusting the element content in the piezoelectric ceramic diaphragm so that the piezoelectric ceramic diaphragm is not easy to break during use. For example, when a voltage is applied to the piezoelectric ceramic sheet, the piezoelectric ceramic sheet vibrates and can maintain continuous vibration for a certain period of time without breaking the piezoelectric ceramic sheet. Compared with the prior art, during use, it is necessary to stop using the piezoelectric ceramic sheet for a certain period of time at intervals to prevent the piezoelectric ceramic sheet from breaking during uninterrupted use. Therefore, the piezoelectric ceramic sheet with a certain proportion of strontium and a certain proportion of niobium has better toughness. The alloy properties of piezoelectric ceramics can avoid the problem of easy breakage and fracture during use. In addition, the piezoelectric constant is increased by changing the various ion ratios of the piezoelectric ceramic crystal so that the piezoelectric constant value reaches a high piezoelectric constant, thereby satisfying the higher mechanical stress generated when a unit electric field strength is applied to it. The larger the piezoelectric constant, the better the piezoelectric performance of the piezoelectric vibrator. And the electromechanical coupling coefficient of the piezoelectric ceramic film can be increased to enhance the coupling effect of the piezoelectric ceramic electric energy and mechanical energy. By improving the electromechanical coupling coefficient index, the efficiency of the piezoelectric vibrator in vibration can be further improved. The mechanical quality factor can be improved by reducing internal friction, reducing the damping of the medium and the loss of the supporting contact, so as to reduce the consumption of internal energy during vibration conversion by improving the mechanical quality coefficient. In addition, due to the phenomenon that the dielectric itself is damaged by heating due to the reduction of electric energy, in order to ensure that the piezoelectric ceramic diaphragm works more stably for a long time, the dielectric loss can be reduced by reducing leakage loss, ionization loss, polarization loss and structural loss. In addition, the lower the dielectric loss, the more stable the working state of the piezoelectric ceramic diaphragm under the action of the alternating electric field. The resonant frequency is also reduced, because the low resonant frequency can improve the performance of piezoelectric materials in the range of medium and low frequency voice signals. The resonant frequency is reduced by increasing the area of ​​the metal sheet and reducing the thickness of the piezoelectric ceramic film. Among them, the thickness of the piezoelectric ceramic film can be adjusted according to the resistance impedance.

[0069] According to another aspect of an embodiment of the present invention, there is provided a sound-generating device, comprising: a vibration unit and a horn unit for generating sound in a frequency band sensitive to human ears as described in any of the above embodiments; Figure 6 FIG. 1 is a schematic diagram of the structure of a horn unit according to an embodiment of the present invention. Figure 6As shown, the horn unit includes a sound wave superposition outlet tube 300 and at least one pair of sound wave introduction tubes; each pair of sound wave introduction tubes includes a first sound wave introduction tube 100 and a second sound wave introduction tube 200; the first sound wave introduction tube 100, the second sound wave introduction tube 200 and the sound wave superposition outlet tube 300 all include a first trapezoidal side surface 100a and a second trapezoidal side surface 100b of the first sound wave introduction tube arranged in parallel and a first square side surface 100c and a second square side surface arranged oppositely; the first trapezoidal side surface 200a and the second trapezoidal side surface 200b of the second sound wave introduction tube and the first square side surface 200c and the second square side surface arranged oppositely; the first trapezoidal side surface 300a and the second trapezoidal side surface 300b of the sound wave superposition outlet tube and the first square side surface 300c and the second square side surface arranged oppositely; and the cross sections of the three are all squares that gradually increase along the sound wave conduction direction; the end of the first sound wave introduction tube with a smaller cross section is formed by a transition from a square cross section to a first circular sound emission port 110; the end of the second sound wave introduction tube with a smaller cross section is formed by a transition from a square cross section to a first circular sound emission port 110 A second circular sound-emitting opening is formed in the crossover; a square sound outlet 310 is formed at one end of the sound wave superposition export tube with a larger cross section; the end of the first sound wave introduction tube with a larger cross section and the end of the second sound wave introduction tube with a larger cross section are both connected to the end of the sound wave superposition export tube with a smaller cross section, and the first trapezoidal side surface of the first sound wave introduction tube and the first trapezoidal side surface of the second sound wave introduction tube are adjacent to form a V-shaped groove 120, and the second trapezoidal side surface 100b of the first sound wave introduction tube and the second trapezoidal side surface 200b of the second sound wave introduction tube are adjacent to the first square side surface 300c and the second square side surface 300d of the sound wave superposition export tube respectively, so that the same two sound wave signals are respectively transmitted from the first circular sound-emitting opening to the first sound wave introduction tube and from the second circular sound-emitting opening to the second sound wave introduction tube, and then superimposed in the sound wave superposition export tube and the superimposed and enhanced sound wave signals are transmitted from the square sound outlet; wherein, a vibration unit is installed for each first circular sound-emitting opening and each second circular sound-emitting opening of the horn unit.

[0070] Specifically, the piezoelectric ceramic sheet in the vibration unit is made of a ceramic sheet with electrodes that has been polarized and aged, and then bonded to a metal sheet. When an alternating voltage is applied, the piezoelectric ceramic sheet produces a telescopic deformation due to the inverse piezoelectric effect, thereby causing the metal sheet to bend and drive the sound. When the piezoelectric sheet stretches, the metal sheet bends upward, and when the piezoelectric sheet contracts, the metal sheet bends downward. If an alternating voltage is applied to the piezoelectric sheet, it will bend and vibrate up and down continuously with the change of the voltage, and then drive the air to vibrate and make a sound. After the sound wave is transmitted to the phase plug, it enters the sound wave outlet of the short horn, the sound wave is squeezed by the phase plug, and after the sound wave is superimposed on the top of the phase plug, it enters the short horn. The short horn increases the compression ratio by restricting the angle of sound wave radiation to achieve the purpose of increasing the sound pressure level. In addition, a fixed structure that cooperates with the sound wave introduction tube of the horn is set at one end of the short horn connected to the horn, which can fix the short horn and the horn together, so that the sound wave cannot propagate from a fixed position to the outside of the horn. The sound waves are transmitted from the short horns at both ends to the horn unit, which effectively concentrates and bundles the sound waves, so that the sound can be concentrated in the front and superimposed infinitely without canceling each other out. The horn unit can have multiple groups of horns, and each horn is provided with two sound wave introduction tubes.

[0071] Among them, the sound wave introduction tube can be a pair, two pairs or three pairs. The first sound wave introduction tube, the second sound wave introduction tube and the sound wave superposition export tube all have a first trapezoidal side, a second trapezoidal side, a first square side and a second square side, and the first trapezoidal side in each structure is parallel to the second trapezoidal side, and the first square side is opposite to the second square side. The sides relative to the first square side and the second square side are aligned. The trapezoid in each structure is connected to the square side. The cross section of the structure formed by connecting the first trapezoidal side, the second trapezoidal side, the first square side and the second square side is square, and the square cross section from the sound wave introduction tube to the position where the sound wave is transmitted from the sound wave export tube is gradually expanded. In addition, the horn unit effectively concentrates the sound waves at the front of the sound wave superposition export tube, gathers and bundles the sound waves, so that the sound can be concentrated in the front and superimposed infinitely without canceling each other out.

[0072] In the horn, the first sound wave introduction tube uses the first circular sounding port to reduce the loss of sound waves during transmission, and similarly, the second sound wave introduction tube uses the second circular sounding port to reduce the loss of sound waves during transmission. By forming adjacent grooves on the sides of the first sound wave introduction tube and the second sound wave introduction tube, the sound is gathered at one point according to the characteristics of the sound wave frequency, and useless sound waves are filtered.

[0073] In some embodiments, the included angle of the V-shaped groove ranges from 15 degrees to 20 degrees.

[0074] Among them, the angle of the V-shaped groove is the angle formed by the first sound wave introduction tube and the second sound wave introduction tube being connected at the sound wave superposition and exporting tube. The bottom of the V-shaped groove can also be other shapes, for example, the bottom of the V-shaped groove can also be a bottom with a certain curvature, presenting a V-shape with a curvature at the bottom. The angle of the V-shaped groove can be any angle within the range of 15 degrees, 16 degrees, 17 degrees, 18 degrees, 19 degrees or 20 degrees. By setting the angle of the V-shaped groove, the directivity of the horn component to the sound wave is improved, and the loss and reduction of the sound wave in the transmission process are reduced. If the angle of the V-shaped groove is too large, the sound waves introduced by the first sound wave introduction tube and the second sound wave introduction tube will be offset. Therefore, through experimental research, it is found that when the angle of the V-shaped groove is set at an angle within 15 degrees to 20 degrees, the sound pressure level of the sound wave in the frequency range of 3.4kHz to 3.8kHz that can be heard by the human ear is higher.

[0075] In some embodiments, the depth of the sound wave superposition outlet tube is between one and two times the wavelength of the incoming sound wave signal.

[0076] Among them, the depth of the sound wave superposition export tube can be 1.1 times, 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times or 2.0 times the wavelength of the incoming sound wave signal. For example, the depth of the sound wave superposition export tube can be 1.2 times. Since the wavelengths of different frequency bands corresponding to different horn units will constrain the sound, therefore. For sound waves of different frequency bands, the length of the sound wave superposition export tube can be set according to the different sound wave frequency bands. If the length of the sound wave superposition export tube is too long, the sound waves with short wavelengths will be eliminated. If the length of the sound wave superposition export tube is short, the frequency characteristics of the sound wave will not be reached. Therefore, the length of the wavelength superposition export tube is set to between one and two times the wavelength of the incoming sound wave signal. In addition to the situation where there is a pair of sound wave introduction tubes, there is also a situation where multiple pairs of sound wave introduction tubes are used as a module, and multiple pairs of sound wave introduction tubes are set to improve the transmission effect of sound waves.

[0077] In addition, when multiple groups of horns are used simultaneously to form a horn array, the square sound outlets of the sound wave superposition and derivation tubes in each horn unit are arranged in the same direction and flush. The sound waves of each horn unit are superimposed on the square sound outlets of the tube and arranged on the same horizontal line, so that sound waves are emitted and sound waves are enhanced. For example, three horn units can be placed horizontally and the three horn units can be kept flush in horizontal positions and the square sound outlets of the three horn units can be oriented in the same direction, or the three horn units can be kept vertically flush in the vertical direction and the directions of the three horn units can be kept the same. If the three horn units are misplaced, the sound waves will cancel each other out during the emission process. Arraying multiple horn units can be conveniently used in a superimposed manner during use.

[0078] Through the Figure 1 The phase plug and Figure 3 The vibration unit for producing sound in the frequency band sensitive to human ears and the Figure 6 The effect of the sound-generating device composed of the horn unit shown is tested. Figure 7 As shown, Figure 7 It shows the frequency response curves produced by different sound generating devices, among which curve 1 shows the effect produced when the optimal device with the optimal parameter structure is used for testing. As an example, a phase plug with the best angle is used, for example, the angle between the planes where two adjacent fins are located is 12 degrees, and the taper range of the first cone is 10 degrees; Figure 1 The phase plug shown, Figure 3 The vibration unit is composed of the short horn shown, a silicone pad with a thickness of 1.5 mm, and a paper sound film with a mass of 0.2 g ± 5%, and Figure 6The speaker shown is a combination of a horn unit that produces the highest sound pressure level. Curve 2 shows the change in frequency response produced by a dynamic speaker in the prior art. In the frequency range that reaches the sensitivity of the human ear, that is, 3kHz to 5kHz in the figure, it can be seen that curve 1 reaches a peak value, while curve 2 does not reach a peak value; and, when the frequency is greater than 10kHz, curve 1 continues to rise, while curve 2 continues to decay. It can be seen from the figure that the sensitivity of the device of the present invention represented by curve 1 is significantly higher than that of the dynamic speaker represented by curve 2 after a frequency of 1.1kHz, and according to the formula, if the sensitivity of the device is 1 dB higher, the sound pressure level (SPL, Sound Pressure Level) will be 1 dB higher. When the frequency of curves 1 and 2 in the figure is 2kHz, the effects produced by the two sound-emitting devices can differ by 20dB, which can demonstrate the great advantages of the present invention. In addition, the higher the frequency, the better the directivity, and at a frequency of 4.3k, it is 25dB higher than the dynamic speaker, which can indicate that the frequency response characteristics of the sound-emitting unit already have strong directivity characteristics. Therefore, using Figure 1 The phase plug shown can increase the sound pressure level of the sound wave, because the phase plug can squeeze the sound wave from between the fins and transmit, and the convergence point of the extension line of each fin can coincide with the cone angle of the first cone, and the sound wave is guided by the fins, so that the sound wave is converged to the cone head, thereby achieving the purpose of increasing the sound pressure level and reducing the attenuation of the sound wave. In addition, using Figure 1 The phase plug and Figure 3 The vibration unit composed of the short horn and the like shown in the figure Figure 6 The sound-generating device composed of the horn unit shown can make the sound more sensitive and stimulating, and improve the transmission directionality of the sound waves and the anti-interference ability.

[0079] In summary, the phase plug, vibration unit and sound-generating device of the embodiment of the present invention are designed accordingly for the phase plug, and the traditional piezoelectric ceramics are modified around the acoustic effect reaction characteristics. According to the characteristics of the human ear sensitive frequency band, targeted designs are carried out to modify the volume and cluster design of the characteristic frequency of the sound-generating cavity. By making a comprehensive modification around the frequency of 3.4K-3.8K Hz, which is sensitive to the human ear, the sound can be made to sound more sensitive and stimulating, and the transmission directionality of the sound wave and the anti-interference performance are improved.

[0080] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in a different order from the embodiments, or several steps can be performed simultaneously.

[0081] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A phase plug for producing sound in a frequency band sensitive to human ears, characterized in that: A phase plug center shaft portion and a plurality of ribs; One end of the central axis of the phase plug is in the shape of a first cone, and the other end is in the shape of a second cone; the bottom of the first cone is completely aligned with and connected to the bottom of the second cone, and the height of the first cone is greater than the height of the second cone, and the taper of the first cone ranges from 10 degrees to 16 degrees; the top of the second cone is used to bond the middle part of the sound film that can match the taper of the second cone; The plurality of fins are vertically arranged on the side of the first cone, and the plane where each of the fins is located coincides with the axial section of the first cone; each of the fins includes a first side, a second side and a third side, the first side of the fin is arranged along the side of the first cone, the second side of each fin is extended along one side of the cross section of the second cone, the contour formed by the second side of all the fins is in the shape of a truncated cone side and is on the same conical surface as the side of the second cone, and the third side of all the fins can extend and converge at a point to form a conical surface contour surrounding the side of the first cone; the angles between the planes where two adjacent fins are located are all set angles; The frequency range of sound that the human ear is sensitive to is 3.5kHz~3.7kHz.

2. The phase plug for producing sound in a frequency band sensitive to human ears as claimed in claim 1, characterized in that: The angle between the planes where two adjacent fins are located ranges from 12 degrees to 18 degrees.

3. The phase plug for producing sound in a frequency band sensitive to human ears as claimed in claim 1, characterized in that: The point where the third sides of all the fins extend and converge is located near the vertex of the first cone.

4. A vibration unit for generating sound in a frequency band sensitive to human ears, characterized in that: It comprises a phase plug, a short horn, a piezoelectric ceramic diaphragm, a sound membrane and a resonance sound-generating cavity for generating sound in a frequency band sensitive to human ears as described in any one of claims 1 to 3; The short horn includes a sound wave restraint portion and a peripheral portion; the sound wave restraint portion includes a contraction portion and a cylindrical portion, and the thinner end of the contraction portion is connected to one end of the cylindrical portion to form a funnel shape; the inner circumference of the contraction portion is arranged around the outside of the third side edges of all the fins of the phase plug to form a sound wave transmission channel between every two adjacent fins; the peripheral portion is arranged around the outer circumference of the sound wave restraint portion to cooperate with the resonance sound cavity to form a resonance sound cavity for accommodating the phase plug, the sound membrane and the piezoelectric ceramic diaphragm; the top of the second cone of the phase plug is bonded to the middle of one side of the sound membrane; the other side of the sound membrane is bonded to the middle of one side of the ceramic surface of the piezoelectric ceramic diaphragm.

5. The vibration unit for generating sound in a frequency band sensitive to human ears as claimed in claim 4, characterized in that: The piezoelectric ceramic diaphragm comprises a first piezoelectric ceramic diaphragm, a second piezoelectric ceramic diaphragm and a metal sheet; the first piezoelectric ceramic diaphragm and the second piezoelectric ceramic diaphragm are symmetrically bonded on both sides of the metal sheet.

6. The vibration unit for generating sound in a frequency band sensitive to human ears as claimed in claim 4, characterized in that: Also includes: A silicone pad is arranged between the peripheral edge of the outer portion of the short horn and the sound membrane.

7. The vibration unit for generating sound in a frequency band sensitive to human ears as claimed in claim 6, characterized in that: The thickness of the silicone pad ranges from 1.5 mm to 3 mm.

8. The vibration unit for generating sound in a frequency band sensitive to human ears as claimed in claim 6, characterized in that: The sound membrane is a paper sound membrane, and the mass of the paper sound membrane is 0.2g±5%.

9. The vibration unit for generating sound in a frequency band sensitive to human ears as claimed in claim 4, characterized in that: The volume range of the resonance sound cavity is 31cm 3 ~35 cm 3 .

10. The vibration unit for generating sound in a frequency band sensitive to human ears as claimed in claim 5, characterized in that: The diameter of the piezoelectric ceramic diaphragm ranges from 26.55 mm to 37.55 mm, and the diameter of the metal sheet ranges from 28 mm to 39 mm, wherein the diameter of the piezoelectric ceramic diaphragm is smaller than the diameter of the metal sheet; The thickness of the piezoelectric ceramic diaphragm ranges from 285µm to 315µm, and the thickness of the metal sheet ranges from 190µm to 210µm; The piezoelectric ceramic diaphragm includes oxygen, titanium, zirconium, lead, strontium and niobium, wherein the content of strontium is in the range of 3.56% to 3.94%, and the content of niobium is in the range of 5.38% to 5.95%.

11. A sound-generating device, characterized in that: include: A vibration unit and a horn unit for generating sound in a frequency band sensitive to human ears as claimed in any one of claims 4 to 10; the horn unit comprises a sound wave superposition outlet tube and at least one pair of sound wave introduction tubes; each pair of sound wave introduction tubes comprises a first sound wave introduction tube and a second sound wave introduction tube; the first sound wave introduction tube, the second sound wave introduction tube and the sound wave superposition outlet tube all comprise a first trapezoidal side surface and a second trapezoidal side surface arranged in parallel and a first square side surface and a second square side surface arranged oppositely, and the cross sections of the three are all squares that gradually increase in size along the sound wave conduction direction; The end of the first sound wave introduction tube with a smaller cross section is formed by a transition from a square cross section to a first circular sound emission port; the end of the second sound wave introduction tube with a smaller cross section is formed by a transition from a square cross section to a second circular sound emission port; the end of the sound wave superposition export tube with a larger cross section is formed with a square sound outlet port; the end of the first sound wave introduction tube with a larger cross section and the end of the second sound wave introduction tube with a larger cross section are both connected to the end of the sound wave superposition export tube with a smaller cross section, and the first trapezoidal side surface of the first sound wave introduction tube and the first trapezoidal side surface of the second sound wave introduction tube are adjacent to form a V-shaped groove, and the second trapezoidal side surface of the first sound wave introduction tube and the second trapezoidal side surface of the second sound wave introduction tube are adjacent to the first square side surface and the second square side surface of the sound wave superposition export tube respectively, so that the same two sound wave signals are respectively transmitted from the first circular sound emission port into the first sound wave introduction tube and from the second circular sound emission port into the second sound wave introduction tube, and then superimposed in the sound wave superposition export tube and the superimposed and enhanced sound wave signals are transmitted from the square sound outlet; wherein, each first circular sound emission port and each second circular sound emission port of the horn unit is respectively equipped with a vibration unit.

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