CN1167862C - Super wide frequency band micropunching acoustical body and its producing method and equipment - Google Patents

Abstract

Super wide frequency band micropunching acoustical body of the invention, the box-like component with back cavity depth D being integrally formed including microperforated panel, with microperforated panel, the perforated plate constant of the microperforated panel

, opposite acoustic resistance , and 1≤r≤5, the back cavity depth , in formula: the penetration hole diameter mm of d- microperforated panel; ω-angular frequency; 1.2 kg m-3 of ρ-atmospheric density; η-the coefficient of viscosity is 1.8 (10) -5kg m-1s-1 in air; The punching rate % of p- microperforated panel; ρ c- characteristic impedance is 400kg s-1 in air; The plate thickness mm of t- microperforated panel; Kr- is with respect to acoustic resistance constant; λ-wave length of sound m; The C- velocity of sound, 340ms-1 in air; F0- maximum sound absorption frequency.

Description

Super wide frequency band micropunching acoustical body and manufacture method thereof and equipment

Technical field

The present invention relates to a kind of sound absorption construction, relate in particular to a kind of super wide frequency band micropunching acoustical body.

Background technology

The present microperforated panel soundabsorbing construction that uses is wanted much wide than other the sound sucting band of resonance sound-absorbing structure, but is also had only 1～2 octave.In order further to strengthen its sound sucting band width, need take double-deck microperforated panel soundabsorbing construction in actual applications.When using this structure, the installation more complicated, the technology of having relatively high expectations just can be ensured the quality of products.In addition, in actual applications, sound wave is not a normal incidence, also wants incident in different directions.Therefore, absorption characteristic is the average of all directions incident.If suppose that the probability of all directions incident is identical, incident at this moment is referred to as to diffuse in and penetrates, and what then work is statistical absorption coefficient.

Theory (Ma Dayou is published in " the theoretical and design of microperforated absorber " on " Chinese science " magazine volume in 1975 38-50 page or leaf) according to microperforated panel soundabsorbing construction, except that basic (or main) sound sucting band, also has some times sound sucting band in high-frequency.This sound sucting band can form important or even main sound absorption part under certain condition.Nearest scientific research has been verified and has tried to achieve the formation rule, and tries to achieve it and basically form rule and in the rule that diffuses in statistical absorption coefficient when penetrating.

Summary of the invention

The objective of the invention is to effectively utilize the inferior sound sucting band of microperforated panel soundabsorbing construction and a kind of super wide frequency band micropunching acoustical body is provided, this sound absorber can increase the sound sucting band of practical application greatly, thereby realize its high frequency sound absorbing capabilities, and under the condition of no special technical requirement, just this sound absorber can be installed easily and be come into operation.

Another purpose of the present invention is to provide a kind of method of making described micropunch sound absorber.

A further object of the present invention is to provide a kind of equipment of implementing to make described micropunch sound absorber method.

Purpose of the present invention mainly is to reach by the perforated plate constant k that reduces little threading, and its concrete technical scheme is as follows.

Super wide frequency band micropunching acoustical body of the present invention comprises microperforated panel and constitutes the box-like member with back cavity depth D of one, the perforated plate constant of described microperforated panel with microperforated panel $k=d\sqrt{\frac{\mathrm{\ω\ρ}}{4\mathrm{\η}}}\≤3,$ Relative acoustic resistance $r=\frac{32\mathrm{\η}}{\mathrm{p\ρc}}\frac{t}{d^2}{k}_r,$ And 1≤r≤5, the described back cavity degree of depth $D=\left(\frac{D}{\mathrm{\λ}}\right)\frac{c}{f_0},$ In the formula:

The penetration hole diameter mm of d-microperforated panel;

ω-angular frequency;

ρ-atmospheric density 1.2kg m ^-3

η-coefficient of viscosity is 1.8 (10) in the air ^-5Kg m ^-1s ^-1

The perforated percentage % of p-microperforated panel;

ρ c-characteristic impedance is 400kg s in the air ^-1

The thickness of slab mm of t-microperforated panel;

k _r-relative acoustic resistance constant, $k_r={(1+\frac{{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C0010331100133.png"\; state="\{\{state\}\}">k</figure-callout>}}^2}{32})}^{\frac{1}{2}}+\frac{\sqrt{2}}{32}\frac{d}{t}\&CenterDot;k;$

The c-velocity of sound, 340m s in the air ^-1

λ-wave length of sound m;

f ₀-maximum sound absorption frequency.

Super wide frequency band micropunching acoustical body of the present invention, wherein said perforated plate constant k=1, acoustic resistance 1≤r＜3 relatively;

Super wide frequency band micropunching acoustical body of the present invention, the thickness of slab t=0.1-5mm of wherein said microperforated panel and box-like member; Described penetration hole diameter d=0.1-0.4mm; Described perforated percentage P=0.1-2%.

Super wide frequency band micropunching acoustical body of the present invention, wherein said t=0.2mm; Described d=0.2mm; Described perforated percentage P=0.3%.

Super wide frequency band micropunching acoustical body of the present invention, wherein said microperforated panel become in corrugated or the described box-like member to be provided with the supporting baffle lattice, and its grid is of a size of 100 * 100-1000 * 1000mm ²Or described microperforated panel becomes in corrugated and the described box-like member to be provided with the supporting baffle lattice, and its grid is of a size of 100 * 100-1000 * 1000mm ²

Super wide frequency band micropunching acoustical body of the present invention, the material of wherein said microperforated panel and box-like member is aluminium sheet, steel plate, plastic plate, plank, cardboard or film.

Super wide frequency band micropunching acoustical body of the present invention, perforation triangularity on the wherein said microperforated panel or square dot matrix are arranged.

The sound absorption characteristics of super wide frequency band micropunching acoustical body of the present invention are decided by the perforated plate constant k of microperforated panel and the relative acoustic resistance r of microperforated panel.To diffusing in the basic sound absorption characteristics of penetrating, inferior sound sucting band in the normal incidence sound absorption characteristics in its absorption characteristic, the diffuse field the numerical value that sound sucting band prolongs to high frequency and the structure of super wide frequency band micropunching acoustical body are elaborated respectively below.

1, normal incidence sound absorption characteristics

The normal incidence sound absorption characteristics comprise normal incident absorption coefficient α n, sound absorption frequency f, back cavity relative thickness D, the half lower frequency limit f that frequently absorbs sound ₁With the upper limiting frequency f that partly frequently absorbs sound ₂Wherein:

${\mathrm{\&alpha;}}_n=\frac{4r}{{(1+r)}^2+{(\mathrm{\&omega;m}-\mathrm{ctg}\left(\frac{\mathrm{\&omega;D}}{c}\right))}^2}$

Maximum sound absorption coefficient ${\mathrm{\&alpha;}}_0=\frac{4r}{{(1+r)}^2}$

Maximum sound absorption frequency (microperforated panel main frequency) f ₀Satisfy

${\mathrm{\&omega;}}_{0}m=\mathrm{ctg}\left(\frac{{\mathrm{\&omega;}}_{0}D}{c}\right)$

ω wherein ₀=2 π f ₀

$\frac{D}{\mathrm{\&lambda;}}=\left(\frac{1}{\mathrm{\&pi;}}\right)\mathrm{ct}{g}^{-1}\left({\mathrm{\&omega;}}_{0}m\right)$

Wavelength X=c/f ₀, at half sound absorption point α=(1/2) α ₀Frequency f ₁And f ₂Satisfy

${\mathrm{\&omega;}}_1-\mathrm{ctg}\left(\frac{{\mathrm{\&omega;}}_{0}D}{c}\right)=-(1+r)$

${\mathrm{\&omega;}}_1-\mathrm{ctg}\left(\frac{{\mathrm{\&omega;}}_{0}D}{c}\right)=+(1+r)$

ω ₁＝2πf ₁，ω ₂＝2πf ₂

At the lower frequency limit f that partly frequently absorbs sound ₁, ω ₁D/c＜1 o'clock, the approximation of desirable ctg is tried to achieve

$\frac{{\mathrm{\&omega;}}_{1}D}{c}=\frac{{\mathrm{ctg}}^{-1}}{\{1+\frac{\mathrm{mc}/\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C0010331100121.png"\; state="\{\{state\}\}">D</figure-callout>}}{1+{(1+r)}^2}\}}$

At the upper limiting frequency f that partly frequently absorbs sound ₂, ω ₀D/c can only try to achieve with numerical calculation.

In the above formula:

The c-velocity of sound is taken as 340m s in air ^-1

The relative acoustic mass of m-

Each parameter of calculating the normal incidence sound absorption characteristics according to above formula and can be tried to achieve sound sucting band sound interval f according to this shown in following table 1 ₂/ f ₁

Table 1 super wide frequency band micropunching acoustical body normal incidence sound absorption characteristics (are decided by basic parameter k, r)

According to the selected arbitrarily f of last table ₀After the value, make the sound absorption scope of micropunch sound absorber be fit to requirement, other value all can be tried to achieve.K in the his-and-hers watches, all available interpolation method of r value is tried to achieve median.

2, diffuse in the basic sound absorption characteristics of penetrating in the diffuse field

The micropunch sound absorber also absorbs oblique incidence sound except that absorbing normal incidence sound, its oblique incidence sound absorption coefficient α (θ) is the function of oblique firing angle θ,

$\mathrm{\&alpha;}\left(\mathrm{\&theta;}\right)=\frac{4r\cos \mathrm{\&theta;}}{{(1+r\cos \mathrm{\&theta;})}^2+{(\mathrm{\&omega;}m\cos \mathrm{\&theta;}-\mathrm{ctg}\left(\frac{\mathrm{\&omega;}D\cos \mathrm{\&theta;}}{c}\right))}^2}$

In the diffuse field, diffuse in and penetrate sound absorption coefficient or statistical absorption coefficient is α ₀To θ average

In the formula:

R is the relative acoustic resistance of microperforated panel

$r=\frac{32\mathrm{\&eta;}}{\mathrm{p\&rho;c}}\frac{t}{d^2}{k}_r$ $k_r={(1+\frac{{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C0010331100133.png"\; state="\{\{state\}\}">k</figure-callout>}}^2}{32})}^{\frac{1}{2}}+\frac{\sqrt{2}}{32}\frac{d}{t}\&CenterDot;k$

ω m is the relative acoustic mass of microperforated panel

$\mathrm{\&omega;m}=\frac{\mathrm{\&omega;}\&CenterDot;t}{\mathrm{pc}}{k}_m$

k _r-relative acoustic resistance constant

k _m-relative acoustic mass constant

The basic sound absorption characteristics of super wide frequency band micropunching acoustical body in the diffuse field are similar during roughly to normal incidence, mainly are that frequency spectrum moves to upper frequency.If α _mBe the maximum sound absorption coefficient in the diffuse field, its frequency is f _m, half frequency sound sucting band is f ' ₁-f ' ₂Maximum sound absorption frequency f during with normal incidence ₀Be main, each value of normalizing, f _m=ξ _mf ₀, the lower frequency limit ratio $\frac{f_1}{f_0}={\mathrm{\&xi;}}_1,$

The upper limiting frequency ratio $\frac{f_2}{f_0}={\mathrm{\&xi;}}_2.\frac{f_m}{f_0},\frac{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="C0010331100121.png"\; state="\{\{state\}\}">f</figure-callout>}}_1^{\&prime;}}{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="C0010331100121.png"\; state="\{\{state\}\}">f</figure-callout>}}_1},\frac{{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="C0010331100133.png"\; state="\{\{state\}\}">f</figure-callout>}}_2^{\&prime;}}{{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="C0010331100133.png"\; state="\{\{state\}\}">f</figure-callout>}}_2}$ Substantially equal, all be about 1.4.The sound interval of sound sucting band

With Substantially equal.In k＜3,1≤r＜3 scopes, maximum sound absorption coefficient equals about 0.8, and maximum sound absorption frequency is about 1.4f ₀, the sound absorption sound interval is identical with normal incidence.Can estimate that according to these relations sound absorption characteristics error in the diffuse field, also can be according to obtaining needed k in the diffuse field, the r value in 10%.As require more accurately the numerical value can be with the maximum sound absorption coefficient α in the following table 2 _mWith its relative frequency ${\mathrm{\&xi;}}_m=\frac{f_m}{f_0}.$ The sound absorption sound interval is still identical with normal incidence, in some cases, and ξ ₂Be that time sound sucting band floods actual ξ ₂Be decided by time sound absorption frequency range.

Table 2 super wide frequency band micropunching acoustical body diffuse field sound absorbing capabilities

k	r＝0.5		r＝1	r＝2	r＝3
						0.5	α m	0.64	0.81	0.85	0.79
ξ m	1.33	1.5	1.5	1.5
					0.8		α m	0.63	0.8	0.85
ξ m	1.33	1.4	1.6
						1	α m	0.63	0.81	0.83	0.76
ξ m	1.33	1.41	1.6	1.6
					2		α m	0.62	0.85	0.71	0.62
ξ m	1.33	1.41	1.41	1.41
						3	α m	0.58	0.66	0.58	0.48
ξ m	1.33	1.33	1.33	1.33

3, inferior sound sucting band makes sound sucting band to high frequency prolongation value

Inferior sound sucting band can make sound sucting band prolong to high frequency, when diffusing in the average α that penetrates sound absorption coefficient _Stat0.4 when above, actual prolongation value ξ _m, can and calculate according to experiment, shown in following table 3.

Table 3 super wide frequency band micropunching acoustical body sound sucting band makes high frequency band prolongation value (α _Stat＞0.4)

k	r＝0.5	1	2	3
					0.5	12.3	16.5	16	15.5
0.8	10	13.5	11.6	10.1
					1	6.3	9.2	7.5	6.3
1.25	5.5	6.7	5	4.3
					1.6	4.5	4.83	4.0	3.8

As shown in Table 3, at r one regularly, the k value is more little, and inferior frequency band sound absorption makes high frequency band prolongation value ξ ₂Big more.Wherein during r=1, ξ ₂Maximum.

4, the structure of super wide frequency band micropunching acoustical body

Selected f ₀With the k value, according to $k=d\sqrt{\frac{\mathrm{\&omega;\&rho;}}{4\mathrm{\&eta;}}},$ Can get the penetration hole diameter of microperforated panel $d=k\sqrt{\frac{4\mathrm{\&eta;}}{{\mathrm{\&omega;}}_0\mathrm{\&rho;}}}$

Wherein $\frac{\mathrm{\&eta;}}{\mathrm{\&rho;}}=1.5{\left(10\right)}^{-5}{m}^2{s}^{-1}$

Perforation center to center distance is b (m)

When perforation quadrate dot matrix is arranged, $b=\left\{\frac{4}{\mathrm{\&pi;}}\frac{32\mathrm{\&eta;t}}{\mathrm{\&rho;c}{d}^4}\right[{(1+\frac{{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C0010331100133.png"\; state="\{\{state\}\}">k</figure-callout>}}^2}{32})}^{\frac{1}{2}}+\frac{\sqrt{2}}{32}k\frac{d}{t}{]}^{\frac{1}{2}}\}\mathrm{mm}$

When perforation triangularity dot matrix is arranged, $b=\left\{\frac{2\sqrt{3}}{\mathrm{\&pi;}}\frac{32\mathrm{\&eta;t}}{\mathrm{\&rho;c}{d}^4}\right[{(1+\frac{{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C0010331100133.png"\; state="\{\{state\}\}">k</figure-callout>}}^2}{32})}^{\frac{1}{2}}+\frac{\sqrt{2}}{32}k\frac{d}{t}{]}^{\frac{1}{2}}\}\mathrm{mm}$

The back cavity degree of depth $D=\left(\frac{D}{\mathrm{\&lambda;}}\right)\frac{c}{f_0}\mathrm{mm},$ According in the table 1 Value calculates the D value.

Under the situation of k=1, choose d=0.16mm, t=0.2mm, f ₀=390HZ under different r, can try to achieve perforation triangularity dot matrix and arrange corresponding b and D, for example:

R=1 tries to achieve b=2.0mm, D=285mm;

R=2 tries to achieve b=2.7mm, D=240mm;

R=3 tries to achieve b=3.3mm, D=200mm.

The method that the present invention makes described super wide frequency band micropunching acoustical body is: use board making microperforated panel and box-like member respectively; Again the microperforated panel that is shaped is placed we of box-like member, with the two riveted joint or be bonded into one and constitute the sound absorber of sealing at beginning.Wherein described microperforated panel can be pressed into corrugated.Also can in described box-like member the supporting baffle lattice be set, its grid is of a size of 100 * 100-1000 * 1000mm ²Also described microperforated panel can be pressed into corrugated and in described box-like member the supporting baffle lattice be set, its grid is of a size of 100 * 100-1000 * 1000mm ², so that improve the intensity of large-scale super wide frequency band micropunching acoustical body.

The back cavity degree of depth of described box-like member $D=\left(\frac{D}{\mathrm{\&lambda;}}\right)\frac{c}{f_0},$ The perforated plate constant of described microperforated panel

$k=d\sqrt{\frac{\mathrm{\&omega;\&rho;}}{4\mathrm{\&eta;}}}\&le;3,$ Relative acoustic resistance $r=\frac{32\mathrm{\&eta;}}{\mathrm{p\&rho;c}}\frac{t}{d^2}{k}_r,$ And 1≤r≤5.

The punch device of the described method of the invention process comprises chuck, card punch that card punch is installed, be arranged on the orifice plate under the described chuck and be sleeved on the guided plate of card punch bottom, and described card punch is most advanced and sophisticated drift or suture needle.This equipment is applicable to that the processing penetration hole diameter is the hole of 0.1-0.2mm, adds man-hour, does not make the whole microperforated panel that passes of drift or suture needle, only exposes its most advanced and sophisticated getting final product, and such hole becomes truncated cone shape.When processing penetration hole diameter when being the hole of 0.2-0.4mm, most advanced and sophisticated drift or suture needle in the described equipment are replaced with drill bit, and described guided plate is sleeved on apart from one section of bit cutting part termination and is a bit larger tham microperforated panel thickness of slab t place.Wherein but drill body part divides overstriking to more than the 1mm.

Described card punch is most advanced and sophisticated drift or suture needle, and its diameter is d, $d=k\sqrt{\frac{4\mathrm{\&eta;}}{{\mathrm{\&omega;}}_0\mathrm{\&rho;}}}.$

The advantage of super wide frequency band micropunching acoustical body of the present invention is: not only adopt the piercing aperture of decimillimeter, also reduced the perforated plate constant k of microperforated panel, make k≤3.Like this, the inferior absorption band of this sound absorber is widened gradually, be arrived to a certain degree, inferior frequency band is with dominant frequency band close proximity.Penetrate in the sound absorption through average diffusing in, the dominant frequency band can connect together with time frequency band, the inferior sound sucting band of consequently adding up sound absorption characteristics is more and more important, sound absorbing capabilities is put off to higher frequency, become the key factor of sound absorption gradually, or even principal element, make frequency range that microperforated panel soundabsorbing construction has a high acoustic absorption coefficient 3 or 4 more than the octave, thereby make this sound absorber become super wide frequency band micropunching acoustical body.In addition, by simple manufacturing method, this sound absorber is made into a sealed whole body separate unit.Therefore, during on-the-spot the installation, do not require superb technology, only need or be mechanically connected on the wall its gluing.In the time of on being contained in ceiling, the lifting of available metal or wooden suspension rod has overcome practical application microperforated panel has been installed separately, and the back cavity depth D is grasped inaccurate and influenced the deficiency of actual acoustically effective, and it is very convenient therefore to install, and sound absorbing capabilities is accurate.This sound absorber be applicable to high temperature, at a high speed, moist and clean place and the special experimental laboratory that requires arranged, also can be widely used in the hall, conference room, broadcasting studio, recording studio, convention hall etc. have specific (special) requirements to tonequality place.

Below in conjunction with accompanying drawing, the most preferred embodiment of super wide frequency band micropunching acoustical body of the present invention is described further.

Description of drawings

Fig. 1 is the structural representation of an embodiment of super wide frequency band micropunching acoustical body of the present invention.

Fig. 2 is the structural representation of box-like member embodiment illustrated in fig. 1.

Fig. 3 is the structural representation that the invention process is made a kind of equipment of described micropunch sound absorber method.

Fig. 4 is the structural representation that the invention process is made another equipment of described micropunch sound absorber method.

Fig. 5 is the sound absorption characteristics curve map of micropunch sound absorber of the present invention.

The specific embodiment

Embodiment

As depicted in figs. 1 and 2, super wide frequency band micropunching acoustical body of the present invention comprises microperforated panel 1 and constitutes the box-like member 2 with back cavity depth D=285mm of one with microperforated panel 1, perforated plate constant K=1 of microperforated panel 1, relative acoustic resistance r=1, microperforated panel 1 and box-like member 2 usefulness aluminium sheets are made, and thickness of slab t is equal to 0.2mm, the penetration hole diameter d=0.2mm of microperforated panel 1, perforated percentage P=0.3%, perforation quadrate dot matrix is arranged its pitch-row b=2.0mm.The long 1000mm of this super wide frequency band micropunching acoustical body, wide 800mm.For strengthening its intensity, microperforated panel 1 is pressed into corrugated, and being provided with 20 sizes in the box-like member 2 is 20 * 20mm ²Square support plate washer lattice 3, and become horizontal four rows, 5 of every rows, vertical 5 row, the configuration that every row are 4.When making the microperforated panel of this super wide frequency band micropunching acoustical body, earlier microperforated panel 1 is pressed into corrugated, press the above-mentioned parameter punching more thereon.When making the box-like member 2 of this super wide frequency band micropunching acoustical body, earlier by curved four limits of above-mentioned back cavity depth D, bonding one-tenth one has the box of open end, again above-mentioned square supporting baffle lattice 3 are put into box, at last microperforated panel 1 is placed the open end of box-like member 2, and make the two bonding one-tenth one sealed whole body.

Equipment of the present invention is to be used for processing perforation on the microperforated panel 1 of super wide frequency band micropunching acoustical body of the present invention specially.As shown in Figure 3 and Figure 4, this equipment comprise install card punch 4 or 4 ' chuck 5, card punch 4,4 ', be arranged on the orifice plate 6 under the chuck 5 and be sleeved on the guided plate 7 of card punch 4,4 ' bottom.Equipment shown in Figure 3 is used for processing the hole of d=0.1-0.2mm, its card punch 4 is most advanced and sophisticated drift (also can be suture needle), add and man-hour microperforated panel 1 is placed between chuck 5 and the orifice plate 6, start chuck 5, most advanced and sophisticated drift spurt microperforated panel 1, make and bore a hole into truncated cone shape, the aperture of backboard face is needed aperture.Equipment shown in Figure 4 is used for processing the hole of d=0.2-0.4mm, its card punch 4 ' and be drill bit.Guided plate 7 is sleeved on apart from one section of bit cutting part termination and is a bit larger tham microperforated panel thickness of slab t place.In addition, also can adopt such drill bit, promptly except that the penetration hole diameter d that its cutting tip diameter equals to process, the overstriking of drilling rod part is to more than the 1mm.When using the equipment of Fig. 4, the perforation on the microperforated panel 1 comes outbreak out.

As shown in Figure 5, inhale characteristic curve for the sound of super wide frequency band micropunching acoustical body of the present invention.Its abscissa is a relative frequency, and ordinate is a sound absorption coefficient.Wherein-◆-expression k=1, the situation of r=1;-●-expression k=1, the situation of r=2; The expression k=1 of-▲-, the situation of r=3,---expression k=4, the situation of r=1,

By curve shown in Figure 5 as can be known, during k=1, its sound absorption curve has presented the superwide frequency band absorption characteristic, and wherein during r=1, performance is best, first absorption point ξ ₂Be 9.2.R=2,3 o'clock, ξ ₂Be respectively 7.5,6.3.And during k=4, its absorption band no longer is the superwide frequency band feature.

Claims (16)

1, a kind of super wide frequency band micropunching acoustical body comprises microperforated panel, it is characterized in that: also comprise the box-like member with back cavity depth D that constitutes one with microperforated panel, the perforated plate constant of described microperforated panel $k=d\sqrt{\frac{\mathrm{\&omega;\&rho;}}{4\mathrm{\&eta;}}}\&le;3,$ Relative acoustic resistance $r=\frac{32\mathrm{\&eta;}}{\mathrm{p\&rho;c}}\frac{t}{d^2}{k}_r,$ And 1≤r≤5, the described back cavity degree of depth $D=\left(\frac{D}{\mathrm{\&lambda;}}\right)\frac{c}{f_0},$ In the formula:

The penetration hole diameter mm of d-microperforated panel;

ω-angular frequency;

ρ-atmospheric density 1.2kg m ^-3

η-coefficient of viscosity is 1.8 (10) in the air ^-5Kg m ^-1s ^-1

The perforated percentage % of p-microperforated panel;

ρ c-characteristic impedance is 400kg s in the air ^-1

The thickness of slab mm of t-microperforated panel;

k _r-relative acoustic resistance constant, $k_r={(1+\frac{k^2}{32})}^{\frac{1}{2}}+\frac{\sqrt{2}}{32}\frac{d}{t}\&CenterDot;k;$

λ-wave length of sound m:

The c-velocity of sound, 340m s in the air ^-1

f ₀-maximum sound absorption frequency.

2, according to the super wide frequency band micropunching acoustical body of claim 1, it is characterized in that: described perforated plate constant k=1, acoustic resistance 1≤r＜3 relatively;

3, according to the super wide frequency band micropunching acoustical body of claim 1, it is characterized in that: the thickness of slab t=0.1-5mm of described microperforated panel and box-like member; Described penetration hole diameter d=0.1-0.4mm; Described perforated percentage P=0.1-2%.

4, according to the super wide frequency band micropunching acoustical body of claim 3, it is characterized in that: described t=0.2mm; Described d=0.2mm; Described perforated percentage P=0.3%.

5, according to the super wide frequency band micropunching acoustical body of claim 3, it is characterized in that: described microperforated panel becomes in corrugated or the described box-like member to be provided with the supporting baffle lattice, and its grid is of a size of: 100 * 100-1000 * 1000mm ²Or described microperforated panel becomes in corrugated and the described box-like member to be provided with the supporting baffle lattice, and its grid is of a size of: 100 * 100-1000 * 1000mm ²

6, according to the super wide frequency band micropunching acoustical body of claim 4, it is characterized in that: described microperforated panel becomes in corrugated or the described box-like member to be provided with the supporting baffle lattice, and its grid is of a size of: 100 * 100-1000 * 1000mm ²Or described microperforated panel becomes in corrugated and the described box-like member to be provided with the supporting baffle lattice, and its grid is of a size of: 100 * 100-1000 * 1000mm ²

7, according to the super wide frequency band micropunching acoustical body of claim 3, it is characterized in that: the material of described microperforated panel and box-like member is aluminium sheet, steel plate, plastic plate, plank, cardboard or film.

8, according to claim 4,5 or 6 super wide frequency band micropunching acoustical body, it is characterized in that: the material of described microperforated panel and box-like member is aluminium sheet, steel plate, plastic plate, plank, cardboard or film.

9, according to claim 4,5,6 or 7 super wide frequency band micropunching acoustical body, it is characterized in that: perforation triangularity on the described microperforated panel or square dot matrix are arranged.

10, super wide frequency band micropunching acoustical body according to Claim 8 is characterized in that: perforation triangularity on the described microperforated panel or square dot matrix are arranged.

11, a kind of method of making the described super wide frequency band micropunching acoustical body of claim 1 is characterized in that: use board making microperforated panel and box-like member respectively; Again the microperforated panel that is shaped is placed we of box-like member, with the two riveted joint or be bonded into one and constitute the sound absorber of sealing, the back cavity degree of depth of described box-like member at beginning $D=\left(\frac{D}{\mathrm{\&lambda;}}\right)\frac{c}{f_0},$ The perforated plate constant of described microperforated panel $k=d\sqrt{\frac{\mathrm{\&omega;\&rho;}}{4\mathrm{\&eta;}}}\&le;3,$ Relative acoustic resistance $r=\frac{32\mathrm{\&eta;}}{\mathrm{p\&rho;c}}\frac{t}{d^2}{k}_r,$ And 1≤r≤5.

12, manufacture method according to claim 11 is characterized in that: described microperforated panel is pressed into corrugated.

13, manufacture method according to claim 11 is characterized in that: be provided with in described box-like member and support the baffle plate lattice, its grid is of a size of 100 * 100-1000 * 1000mm ²

14, manufacture method according to claim 12 is characterized in that: be provided with in described box-like member and support the baffle plate lattice, its grid is of a size of 100 * 100-1000 * 1000mm ²

15, a kind of punch device of manufacturing microperforated panel, comprise chuck, card punch that card punch is installed, it is characterized in that: also comprise the guided plate that is arranged on the orifice plate under the described chuck and is sleeved on the card punch bottom, described card punch is most advanced and sophisticated drift or suture needle, its diameter is d

$d=k\sqrt{\frac{4\mathrm{\&eta;}}{{\mathrm{\&omega;}}_0\mathrm{\&rho;}}}.$

16, equipment according to claim 15 is characterized in that: replace described most advanced and sophisticated drift or suture needle with drill bit, and described guided plate is sleeved on apart from one section of bit cutting part termination and is a bit larger tham microperforated panel thickness of slab t place.

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