CN207266275U - A kind of audio directional transducer - Google Patents
A kind of audio directional transducer Download PDFInfo
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- CN207266275U CN207266275U CN201721298346.XU CN201721298346U CN207266275U CN 207266275 U CN207266275 U CN 207266275U CN 201721298346 U CN201721298346 U CN 201721298346U CN 207266275 U CN207266275 U CN 207266275U
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Abstract
The utility model provides a kind of audio directional transducer, including upper strata array, interlayer bulkhead, the first lower arrays, first electrode, piezoelectric membrane, the second lower arrays, second electrode, fastening unit and vacuum box；Upper strata array, interlayer bulkhead, the first lower arrays, piezoelectric membrane and the second lower arrays are cascading, and are fixed on by fastening unit on vacuum box；First electrode and second electrode are used to for external voltage to be loaded into the first lower arrays and the second lower arrays respectively；First lower arrays and the second lower arrays are arranged in regular hexagon shape including multiple circular array units；Upper strata array includes multiple circular array units and is arranged in regular hexagon shape；The ratio of the length of line in line and upper strata array in lower arrays between two circular array units of lie farthest away between two circular array units of lie farthest away is 1：(0.8~1.2).The audio directional transducer of the utility model has high sound pressure level and good directive property concurrently.
Description
【Technical field】
It the utility model is related to a kind of pzt array structure with audio frequency directional.
【Background technology】
Audio frequency directional technology is paid close attention to since the 1960s be subject to more and more researchers, and is gradually applied to
Among the work and life of people.Since air is not proper perfect gas, for loudness is very big or frequency very
High sound wave, traditional small amplitude acoustic theory have not applied to.According to the theory of acoustic parametric arrays, when two row have obvious be directed toward
Property, frequency is respectively f1, f2Ultrasonic wave when propagating in the same direction, it may occur that interaction produces 2f1, 2f2, (f1+f2),
(f1-f2) etc. frequency sound wave.As sound wave is constantly propagated forward, high-frequency sound wave can decay quickly to be finished, and low frequency
Acoustic attenuation more slowly so as to propagate relatively long distance, be achieved in the propagation of directive property audible sound.
In audio frequency directional system, signal processing and transducer are designed as core component, decide directive property sound
The output performance of ripple.Research of the recent decades for signal processing is more, and by testing and improving repeatedly, researcher has opened
Send efficient, the low optimization algorithm of the distortion factor, disclosure satisfy that the requirement of practical application.And the research for PZT (piezoelectric transducer) into
Exhibition is relatively slow, restricts the performance boost and application of audio directional loudspeaker.Therefore, the high performance audio frequency of utility model
Directional transducer has great importance.
The disclosure of background above technology contents is only used for utility model design and the technical side that auxiliary understands the utility model
Case, it not necessarily belongs to the prior art of present patent application, shows the above in this patent Shen in no tangible proof
In the case of the applying date please is disclosed, above-mentioned background technology should not be taken to the novelty and creativeness of evaluation the application.
【Utility model content】
Technical problem to be solved in the utility model is：Above-mentioned the deficiencies in the prior art are made up, propose that a kind of audio frequency is determined
To transducer, high sound pressure level and good directive property are had concurrently.
The technical problem of the utility model is solved by following technical solution：
A kind of audio directional transducer, including upper strata array, interlayer bulkhead, the first lower arrays, first electrode, piezoelectricity are thin
Film, the second lower arrays, second electrode, fastening unit and vacuum box；The upper strata array, interlayer bulkhead, the first lower arrays,
Piezoelectric membrane and the second lower arrays are cascading, and are fixed on by fastening unit on vacuum box, in the vacuum box
Portion corresponds to the region of the piezoelectric membrane formed with cavity, for providing subnormal ambient for the piezoelectric membrane；First electricity
Pole is arranged on first lower arrays, and the second electrode is arranged on second lower arrays, the first electrode
It is used to for external voltage to be loaded into first lower arrays and second lower arrays respectively with second electrode；Described first
Lower arrays and the second lower arrays are identical structure, including multiple circular array units are arranged in regular hexagon shape, described
For the diameter a1 of circular array unit in the range of 17.8~26.8mm, the spacing of adjacent circular arrays unit is a1+5mm；Institute
State upper strata array and include multiple circular array units and be arranged in regular hexagon shape, the spacing d2 of adjacent circular arrays unit exists
In the range of 3.42~6.8mm, a diameter of d2-2mm of circular array unit；Two circles of the lie farthest away in lower arrays
Company between the length of line between array element and two circular array units of the lie farthest away in the upper strata array
The ratio of the length of line is 1：(0.8~1.2).
The beneficial effect that the utility model is compared with the prior art is：
The audio directional transducer of the utility model, securing trie piezoelectric film, and lower floor's battle array are superimposed by two lower arrays
Each array element in row for specific dimensions scope circular array unit and be arranged in regular hexagon according to specific dimensions, at the same time
One upper strata array is superimposed by interlayer bulkhead, and the circle list that each array element in the array of upper strata is specific dimensions scope
Member and regular hexagon is arranged according to specific dimensions, in this way, lower arrays structure is obtained compared with high sound pressure level for transducer, upper strata battle array
Array structure obtains preferable directive property for transducer, both cooperations finally cause lower arrays and upper strata array is combined
Array structure had both had the characteristics that sound pressure level was high, it may have the characteristics of directive property is good.
【Brief description of the drawings】
Fig. 1 is the structure diagram of the PZT (piezoelectric transducer) in the utility model embodiment；
Fig. 2 a be the utility model embodiment combined type array in lower arrays structure diagram；
Fig. 2 b are the structure diagrams of the combined type array array at the middle and upper levels of the utility model embodiment；
Fig. 3 a are the finite element model figures that the lower arrays simulated in the utility model embodiment work independently；
Fig. 3 b are the finite element model figures that the upper strata array simulated in the utility model embodiment works independently；
Fig. 3 c are the finite element model figures for the composite array work simulated in the utility model embodiment；
Fig. 4 is the analog result contrast signal of the output sound pressure level of three kinds of arrays in the utility model embodiment
Figure；
Fig. 5 is the analog result contrast schematic diagram of the directive property of three kinds of arrays in the utility model embodiment；
Test platform architecture schematic diagram when Fig. 6 is testing transducer in the utility model embodiment；
Fig. 7 is survey of the sound pressure level of lower arrays and composite array to frequency response in the utility model embodiment
Test result and analog result；
Fig. 8 is the test result of the directive property of lower arrays and composite array in the utility model embodiment.
【Embodiment】
With reference to embodiment and compare attached drawing the utility model is described in further details.
A kind of audio directional transducer, including upper strata array, interlayer bulkhead, the first lower floor are provided in present embodiment
Array, first electrode, piezoelectric membrane, the second lower arrays, second electrode, fastening unit and vacuum box.
Wherein, upper strata array, interlayer bulkhead, the first lower arrays, piezoelectric membrane and the second lower arrays are stacked gradually and set
Put, and be fixed on by fastening unit on vacuum box, inside vacuum box the region of corresponding piezoelectric membrane formed with cavity, for for
Piezoelectric membrane provides subnormal ambient.Usually, vacuum valve can be set by the vacuum box other end, by vacuum valve to being taken out in cavity
Vacuum for the piezoelectric membrane above vacuum box so that provide subnormal ambient.
First electrode is arranged on the first lower arrays, and second electrode is arranged on the second lower arrays, first electrode and
Second electrode is used to for external voltage to be loaded into the first lower arrays and the second lower arrays respectively, and then is clamped piezoelectricity
The upper and lower surface of film applies voltage signal.
First lower arrays and the second lower arrays are identical structure, including multiple circular array units are arranged in positive six side
Shape shape, for the diameter a1 of circular array unit in the range of 17.8~26.8mm, the spacing of adjacent circular arrays unit is a1+
5mm.Upper strata array includes multiple circular array units and is arranged in regular hexagon shape, the spacing d2 of adjacent circular arrays unit
In the range of 3.42~6.8mm, a diameter of d2-2mm of circular array unit.Two circles of the lie farthest away in lower arrays
Line between the length of line between shape array element and two circular array units of the lie farthest away in the array of upper strata
Length ratio be 1：(0.8~1.2).
Specifically, in the composite array structure being made of this pair of lower arrays and upper strata array, the output sound of transducer
Arbitrarily downgrade mainly is influenced by the structure of lower arrays, and directive property is mainly influenced by the structure of upper strata array.
To obtain maximum output sound pressure level, the working frequency of transducer should be close with the intrinsic frequency of transducer.It is right
In the array element of thin discs shape, there are following relation with cell radius r by its intrinsic frequency f：
Wherein, Y, σ, ρ are respectively the Young's modulus of piezoelectric membrane, Poisson's ratio and density, its numerical value can survey to obtain.Generally
Ground, for the transducer array that working frequency is 40-60kHz, it is 8.9- to calculate circular array cell radius r
13.4mm, namely diameter a1 in the range of 17.8~26.8mm, it can be achieved that larger output sound pressure level.And in circle list
In the case of the diameter of member determines, the spacing d1 of adjacent circular arrays unit is set to may be such that array element more closes for a1+5mm
It is suitablely arranged evenly to open.
To obtain preferable directive property, spacing d2 and wave length of sound λ's between the array element through studying upper strata array
Ratio should be between 0.6-0.8.The sound wave for being 40-60kHz for the frequency propagated in atmosphere, its wavelength is 5.7-8.5mm,
Thus the value for setting spacing d2 is 3.42-6.80mm.In the case of spacing between adjacent circular arrays unit determines, if
A diameter of d2-2mm of circular array unit is put, may be such that circular array unit size is suitable, and it is arranged evenly also convenient.
By in the length of the line between two circular array units of the lie farthest away in lower arrays and upper strata array
Lie farthest away two circular array units between the ratio of length of line be arranged to 1：(0.8~1.2), i.e. lower floor battle array
Large scale, the arrangement of big spacing array element of negligible amounts are classified as, upper strata array is a fairly large number of small size, small spacing array element is arranged
Row, and the area of the array distribution after arrangement is closer to, so that may be such that levels array is utilized effectively, it is final to obtain
The composite array structure that sound pressure level is high, directive property is good.It should be noted that circular array unit in upper strata array and lower arrays
Particular number does not limit, no matter quantity, as long as being arranged into the array of regular hexagon in the form of meeting above-mentioned requirements i.e.
The effect promoting in terms of sound pressure level and directive property can finally be obtained.
As shown in Figure 1, the structure diagram for a specific audio directional transducer.Wherein, 2 be the first lower arrays, 1
For the second lower arrays, structure is identical, including substrate and the multiple circular array units being disposed on the substrate.Material is closed for aluminium
Gold, size are 100mm × 100mm × 3mm.3 be PVDF piezoelectric film, and size is 100 × 100 × 0.02mm, its upper and lower surface is divided
Do not contacted with the first lower arrays 2 and the second lower arrays 1.As a kind of flexible piezoelectric material, polyvinylidene fluoride (PVDF)
For piezoelectric film compared to piezoceramic material, its acoustic impedance to air is low, shakes so as to reduce piezoelectric and be propagated into air
Loss when dynamic.Meanwhile PVDF has preferable toughness, can be effective against fatigue fracture caused by dither.Secondly,
PVDF is easy to large area production, and has preferable uniformity and stability, so as to improve the equal of transducer array performance
One property.It is therefore preferable that it is PVDF piezoelectric film.
4 and 5 be respectively two electrodes, and material is copper.Wherein, electrode 4 is arranged on lower arrays 1, and electrode 5 is arranged on down
On layer array 2.The vacant end of electrode 4 and 5 is connected with exterior signal source, so that external voltage is loaded into lower arrays respectively
On 1 and 2, and then the PVDF piezoelectric film 3 for middle clamping provides electric signal.
The material of upper strata array 7 is aluminium alloy, and size is 100 × 100 × 2mm.6 be interlayer bulkhead, and material is aluminium alloy,
Size is 100 × 100 × 2mm, between 7 and first lower arrays 2 of upper strata array.Interlayer bulkhead 6 has certain thickness, its
The ultrasonic wave that the space framed is generated by PVDF piezoelectric film 3 under the electric signal effect loaded provides certain transmission space.
Second lower arrays 1, the first lower arrays 2, PVDF piezoelectric film 3, interlayer bulkhead 6, upper strata array 7 pass through plastic spiral
Nail 8 is fastenedly connected with plastic nut 9, meanwhile, it is fixed together, does not produce between PVDF piezoelectric film 3 and lower arrays 1,2
Relative displacement.
It is PVDF by way of taking out negative pressure when PZT (piezoelectric transducer) works to improve the output performance of PVDF piezoelectric film 3
Piezoelectric film 3 applies pretightning force so that piezoelectric can be fully converted to external deformation because of the internal stress that alternating voltage produces.Cause
This, sets a vacuum box 10 below transducer array, wherein one side coordinates with transducer array, and applies ab glue in joint
To ensure air-tightness, the other end is equipped with vacuum valve, so as to provide subnormal ambient at work for PVDF piezoelectric film 3.
Fig. 2 a are the structure diagram of lower arrays.The diameter a1 of each circular array unit is 25mm, array pitch d1
For 30mm.Circular array unit is in regular hexagon array arranged distribution, i.e. array is in x-axis, and on the direction of 60 ° of x-axis angle,
The circle center distance of adjacent two circular cell is d1.In the square substrate that size is 100 × 100mm, 7 are arranged in the form of above-mentioned
The length of line between a circular array unit, i.e. the two of lie farthest away circular array unit is 85mm.Fig. 2 b are upper strata
The structure diagram of array.The diameter a2 of each circular array unit is 4mm, and array pitch d2 is 6mm.Size for 100 ×
127 circular array units, i.e. the two of lie farthest away are arranged in the square substrate of 100mm in the form of regular hexagon array
The length of line between circular array unit is 76mm.The hole in four corners of substrate is illustrated as screw 8 and wears in Fig. 2 a and Fig. 2 b
The through hole crossed, diameter are 5mm.
For the output performance of the transducer of said structure, first by COMSOL multiple physical fields Finite Element Simulation Software into
Row simulation.It is respectively that lower arrays work independently, upper strata array works independently, levels composite array as shown in Fig. 3 a~3c
The illustraton of model of work.Material property in model is configured according to the material property used in practical devices.PVDF piezoelectric film
Upper surface apply the alternating voltage that peak value is 20V, lower surface be ground terminal (potential permanent be 0).For the half of sound field least significant end
Spherical shell is arranged to plane wave propagation, shows that Acoustic Wave Propagation then continues to propagate at this, does not produce reflection.
As shown in Figures 4 and 5, be respectively three kinds of forms array simulation output performance comparison schematic diagram.Fig. 4 is three kinds of battle arrays
The contrast of the simulation sound pressure level output response of row, its analog frequency scope is 35-65kHz (working frequencies of practical devices).From
The frequency response rule that Fig. 4 can be seen that composite array is substantially consistent with lower arrays, has higher response sound pressure level.And
Why respond that sound pressure level is higher, be because the circular array unit of radius 12.5mm there are resonance effect, pressure near 40kHz
Electrolemma can produce larger deformational displacement.For composite array structure, due to blocking there are upper strata array, composite array
The sound pressure level intensity of output is declined slightly when working independently relative to lower arrays, and peak response sound pressure level is 78dB.And upper strata
The array element size of array is smaller, and array (can be calculated almost without the resonance effect of radial direction according to correlation formula under 35-65kHz
It is about 268kHz to obtain its resonant frequency), therefore the output response of sound pressure level is relatively weak in the frequency range of 35-65kHz.
Fig. 5 is the contrast of the simulation directive property performance of three kinds of arrays.From fig. 5, it can be seen that the directive property collection of composite array
Middle degree between two kinds of arrays work independently when directive property good and bad degree between.It is other compared with the directive property of lower arrays
The intensity of valve substantially weakens, and the half-power angle of release of main lobe is about 15 °, and the acuity of the generally directive property of acoustic beam is carried
It is high.This shows the adjustment effect by upper strata array, and the directive property of lower arrays can be improved.
As follows by the output performance of actual test transducer, its actual performance data is analyzed.
It is illustrated in figure 6 connection diagram during test.The signal source of test is signal generator 1 and signal generator
The simple signal of 2 inputs at the same time, frequency is respectively 40kHz and 45kHz, and measuring distance is arranged to 0.5m, and input voltage passes through electricity
Pressure amplifier brings up to 60V and powers for transducer.Certain negative pressure is extracted in transducer is tensioned PVDF piezoelectric film.Transducer is put
It is placed on test table, is adjusted by the rotation of test table, signal receiving end is existed using the measurable transducer that obtains of acoustimeter
Sound pressure level size under different angle.During test, the center of acoustimeter and transducer in the same horizontal line, with test table
Rotation, sound pressure level intensity of the center of transducer under the different angle relative to acoustimeter is recorded, further according to directive property
The definition of function calculates corresponding directivity function.
Actual tests of the Fig. 7 for the sound pressure level of transducer composite array and single lower arrays to the response curve of frequency
As a result, and contrasted with analog result.According to test result, the resonance peak of lower arrays is near 43kHz, peak response
Sound pressure level is 87dB.For the resonance peak of composite array near 42kHz, peak response sound pressure level is 83dB.The resonance peak of the two is surveyed
Test result is there are certain error, but the variation tendency of global response is basically identical, and average sound pressure level is in more than 70dB, output performance
It can meet application demand.Due to blocking for upper strata array, the output sound pressure level of composite array is individually made compared to lower arrays
Used time is low, this is also substantially consistent with the analog result of Fig. 4.
Fig. 8 is the directive property test result of transducer composite array and single lower arrays.As shown in figure 8, by making
With composite array, its directive property increases, and is consistent with the rule of simulation and forecast in Fig. 5.By the test result, can be shown that small
The sound wave that array element, the upper strata array of small spacing can send the lower arrays of larger array element, larger spacing is readjusted,
So as to improve it is compound after array directive property.The directive property half-power angle of release of transducer devices output brings up to 30 ° by 60 °.
By above-mentioned analog result and actual test as a result, showing the transducer array of present embodiment can solve
Output sound pressure level and directive property are difficult to the contradiction coordinated in field of transducer, and the transducer of present embodiment can have concurrently loudly
Arbitrarily downgrade and the advantages of good directive property.
Above content is to combine specific preferred embodiment further detailed description of the utility model, it is impossible to
Assert that the specific implementation of the utility model is confined to these explanations.For the ordinary skill of the utility model technical field
For personnel, some replacements or obvious modification, and performance or purposes are made without departing from the concept of the premise utility
It is identical, it should all be considered as belonging to the scope of protection of the utility model.
Claims (7)
- A kind of 1. audio directional transducer, it is characterised in that：Including upper strata array, interlayer bulkhead, the first lower arrays, the first electricity Pole, piezoelectric membrane, the second lower arrays, second electrode, fastening unit and vacuum box；The upper strata array, interlayer bulkhead, first Lower arrays, piezoelectric membrane and the second lower arrays are cascading, and are fixed on by fastening unit on vacuum box, described The region of the corresponding piezoelectric membrane is formed with cavity inside vacuum box, for providing subnormal ambient for the piezoelectric membrane；Institute State first electrode to be arranged on first lower arrays, the second electrode is arranged on second lower arrays, described First electrode and second electrode are used to for external voltage to be loaded into first lower arrays and second lower arrays respectively； First lower arrays and the second lower arrays are identical structure, including multiple circular array units are arranged in regular hexagon shape Shape, for the diameter a1 of the circular array unit in the range of 17.8~26.8mm, the spacing of adjacent circular arrays unit is a1+ 5mm；The upper strata array includes multiple circular array units and is arranged in regular hexagon shape, between adjacent circular arrays unit Away from d2 in the range of 3.42~6.8mm, a diameter of d2-2mm of circular array unit；Two of lie farthest away in lower arrays Two circular array units of the lie farthest away in the length of the line between a circular array unit and the upper strata array it Between line length ratio be 1：(0.8~1.2).
- 2. audio directional transducer according to claim 1, it is characterised in that：First lower arrays and the second lower floor A diameter of 25mm of circular array unit in array, the spacing of adjacent circular arrays unit is 30mm.
- 3. audio directional transducer according to claim 1, it is characterised in that：Circle list in the upper strata array A diameter of 4mm of member, the spacing of adjacent circular arrays unit is 6mm.
- 4. audio directional transducer according to claim 1, it is characterised in that：The piezoelectric membrane for PVDF piezoelectric film or Person's piezoelectric ceramics.
- 5. audio directional transducer according to claim 1, it is characterised in that：The fastening unit includes screw and setting Nut on the vacuum box, the screw sequentially pass through the upper strata array, the first lower arrays, on the second lower arrays Through hole, be fastenedly connected with the nut.
- 6. audio directional transducer according to claim 1, it is characterised in that：The upper strata array, interlayer bulkhead, first Lower arrays, piezoelectric membrane and the second lower arrays are square structure.
- 7. audio directional transducer according to claim 1, it is characterised in that：The upper strata array, interlayer bulkhead, first The material of lower arrays and the second lower arrays is aluminium alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721298346.XU CN207266275U (en) | 2017-10-10 | 2017-10-10 | A kind of audio directional transducer |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721298346.XU CN207266275U (en) | 2017-10-10 | 2017-10-10 | A kind of audio directional transducer |
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| CN207266275U true CN207266275U (en) | 2018-04-20 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107484085A (en) * | 2017-10-10 | 2017-12-15 | 清华大学深圳研究生院 | A kind of audio directional transducer |
| CN108837305A (en) * | 2018-05-15 | 2018-11-20 | 清华大学 | Flexible pacemaker and bioelectricity monitoring method based on flexible pacemaker |
-
2017
- 2017-10-10 CN CN201721298346.XU patent/CN207266275U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107484085A (en) * | 2017-10-10 | 2017-12-15 | 清华大学深圳研究生院 | A kind of audio directional transducer |
| CN108837305A (en) * | 2018-05-15 | 2018-11-20 | 清华大学 | Flexible pacemaker and bioelectricity monitoring method based on flexible pacemaker |
| CN108837305B (en) * | 2018-05-15 | 2021-04-13 | 清华大学 | Flexible pacemaker and bioelectricity monitoring method based on flexible pacemaker |
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Granted publication date: 20180420 Termination date: 20201010 |