CN205158899U - Combination perforated plate - Google Patents

Abstract

The utility model provides a combination perforated plate, includes middle panel, be equipped with the perforation by centre of a circle spurious radiation on the middle panel, the perforation is cyclic annular the distribution, the perforation aperture is 2~8mm, the punching rate is 1~2%, the median surface inboard is equipped with the air bed of compriseing circular hose, be 1.39% at the punching rate, the aperture is for 2mm's the perforation whole area at 3 o'clock with the comparing of the perforation whole area that the aperture is 4mm, and full sound absorption effect frequently is best. Beneficial effect: be equipped with the perforation by centre of a circle spurious radiation on the middle panel, the perforation is cyclic annular the distribution, the perforation aperture is 2~8mm, under the punching rate is 1~2% configuration state, both guaranteed the structural stability of perforated plate to make it have good full frequency acoustic absorption performance simultaneously.

Description

A kind of combination perforated plate

Technical field

The utility model relates to a kind of sound insulating structure, relates in particular to a kind of sound panel combining perforation.

Background technology

Acoustic absorbant is mainly divided into sound-absorbing porous material and resonance sound-absorbing structure by structure.Then common with perforated plate in resonance sound-absorbing structure, it is usually used in building industry and noise control engineering, as the protection slab of resonance sound-absorbing structure element and acoustic absorbant.The sound absorbing mechanism of perforated plate acoustic absorbant, has identical place with porosint, and its different feature is that perforated plate acoustic absorbant is the feature utilizing resonator, more effective acoustic energy is transformed into thermal energy consumption.This sound absorption structure is not adopt stringiness acoustic absorbant, but adopts the materials such as aluminium sheet, steel plate, plastic plate to make, and therefore has not water funk and moisture, fire prevention, clean, pollution-free, high temperature resistant, the feature of the impact of high velocity air can be born, and its weak point to be sound sucting band narrow, near resonant frequency, acoustical absorption coefficient is very high, can close to 1, but a deviation resonance peak, acoustical absorption coefficient just declines rapidly, and therefore it is only applicable to the single-frequency sound absorbing medium and low frequency.This is also that it can not the reason of alternative fiber acoustic absorbant in acoustic absorbant field for a long time.

Simultaneously the sound absorption principle of perforated plate be with hole near frictional dissipation absorb acoustic energy, when percentage of perforation is certain, the acoustic resistance of small-hole fenestration plate is comparatively large, and better, and the acoustic resistance of macropore perforated plate is less for acoustically effective, and acoustically effective is poor; And they all have selective absorbing to the noise of different frequency bands; Consider above and the principle mathematically planned as a whole at 2, we will try one's best in the process making perforated plate increases the number of aperture more, the number adding some other larger hole suitable on this basis, widen the sound sucting band of perforated plate as far as possible, make the acoustically effective of perforated plate close to best full-frequency sound absorption effect.But adopt the perforated plate processed in this way often there is many perforation, not only make the procedure of processing of perforated plate more loaded down with trivial details, and make the material of perforated plate own more fragile.

Utility model content

The utility model, for the deficiency of current sound insulating structure, proposes a kind of sound insulating structure with perforated plate, and the utility model provides a kind of combination perforated plate.

A kind of combination perforated plate, comprise centre panel, described centre panel is provided with by the center of circle to extraradial perforation, described perforation distributes in the form of a ring, described piercing aperture is 2 ~ 8mm, and described percentage of perforation is 1 ~ 2%, is provided with the air layer be made up of flexible pipe in described centre panel.

Described piercing aperture is that 2mm is or/and 4mm is or/and 8mm; Described percentage of perforation is 1.39%.

Described aperture is the ratio that the perforation total area and the aperture of 2mm is the perforation total area of 4mm is 3.

Described flexible pipe is for circle and diameter is 0.33cm.

Described centre panel both sides are provided with top panel and lower panel, and described centre panel and top panel are equipped with some layers of pugging between centre panel and lower panel.

The packing material of the described pugging of some layers is glass wool, asbestos, porous foam, polyurethane sea or metal fibre.

Centre panel all adopts aluminium material.

Described top panel, lower panel all adopt the stainless steel that rotproofness is strong.

Beneficial effect: be provided with by the center of circle to extraradial perforation in described centre panel, described perforation distributes in the form of a ring, described piercing aperture is 2 ~ 8mm, described percentage of perforation is under the configuration state of 1 ~ 2%, both ensure that the structural stability of perforated plate, and make it have best full-frequency sound absorption performance simultaneously.

Accompanying drawing explanation

Fig. 1 is structural drawing of the present utility model.

Fig. 2 under percentage of perforation P=1.39%, experimental data form.

Fig. 3 under percentage of perforation P=1.39%, experiment test linear graph.

Embodiment

By reference to the accompanying drawings the utility model is described in further detail now.These accompanying drawings are the schematic diagram of simplification, only basic structure of the present utility model are described in a schematic way, and therefore it only shows the formation relevant with the utility model.

The utility model, for the deficiency of current sound insulating structure, proposes a kind of sound insulating structure with perforated plate, and the utility model provides a kind of combination perforated plate.A kind of combination perforated plate, comprise centre panel, described centre panel is provided with by the center of circle to extraradial perforation, described perforation distributes in the form of a ring, described piercing aperture is 2 ~ 8mm, and described percentage of perforation is 1 ~ 2%, is provided with the air layer be made up of flexible pipe in described centre panel.Under this configuration state, both ensure that the structural stability of perforated plate, and make it have best full-frequency sound absorption performance simultaneously.

Prove through many experiments test: when percentage of perforation P=1.39% is constant, experiment measuring has been carried out by the average sound absorption coefficient of perforated plate that combines three holes (aperture is respectively 2mm, 4mm and 8mm) of different number ratio and frequency span, all draw when keeping percentage of perforation constant, aperture is ratio that hole area and the aperture of 2mm is the hole area of 4mm when being about 3, namely has best full-frequency sound absorption performance.

Described flexible pipe is for circle and diameter is 0.33cm, is combined, improve the acoustically effective of full frequency band by the best distribution of different pore size.

Described centre panel both sides are provided with top panel and lower panel, and described centre panel and top panel are equipped with some layers of pugging between centre panel and lower panel, enhance stability and the acoustically effective of perforated plate.

The packing material of the described pugging of some layers is glass wool, asbestos, porous foam, polyurethane sea or metal fibre, makes perforated plate can carry out independent assortment assembling according to different actual demands, substantially increases overall dirigibility.

Centre panel all adopts aluminium material, and the resistance to overturning enhancing perforated plate simultaneously, effectively can be conducted the heat because sound transmission produces, avoid destroying its endothecium structure.

Described top panel, lower panel all adopt the stainless steel that rotproofness is strong, effectively prevent external corrosion source from entering the inner corruption causing its endothecium structure of perforated plate.

Principle:

What the utility model improved is sound absorbent perforated structure.This sound absorption structure is made up of the thin plate of various perforation and the air layer of their behinds.The sound absorbing mechanism of this structure is when incident sound wave frequency is identical with the natural frequency of this system, piercing aperture air will because of resonance high vibration.In vibration processes, absorb acoustic energy mainly due to the frictional dissipation near perforation, thus carry out absorption of noise.

Perforated plate sound absorption characteristics depend primarily on thickness of slab, aperture, air layer thickness and primer, percentage of perforation.The acoustical absorption coefficient looking into the current full range to improving perforated plate of new discovery has a lot of research, but be that this starts with on the one hand from the degree of depth of the thickness of material, percentage of perforation and cavity mostly, but the impact on perforated plate acoustical absorption coefficient with regard to pore size and combination thereof, be not concerned in current research, therefore the utility model is started with from aperture angle, study the optimum condition of different size aperture combination, thus improve the acoustically effective of full range.

Computing formula according to perforated plate resonant frequency:

$f=\frac{c}{2\mathrm{\π}}\sqrt{\frac{p}{(t+0.8d)L}}---\left(1\right)$

L(cm)	t(cm)	d(cm)	c(cm/s)	p
					Air layer thickness after plate	The thickness of plate	Aperture	The velocity of sound	Percentage of perforation

The absorption of perforation acoustic absorbant to the noise of different frequency range is selectable, under other affects the certain condition of the acoustical absorption coefficient factor (comprising percentage of perforation etc.) of perforated plate, formula is calculated according to perforated plate resonant frequency, the resonant frequency of macropore is in medium and low frequency place, more to the noise absorbent of low frequency, and the resonant frequency of aperture is at high frequency treatment, many to the noise absorbent of high frequency, the less absorption coefficient curve in visible aperture more moves to high frequency direction.Owing to considering the influence factor of above-mentioned sound absorbent perforated structure, the utility model just design, under percentage of perforation and the certain condition of other factors, visits the impact that different pore size combination exists perforated plate full-frequency sound absorption effect.And find the best distribution point in large, medium and small aperture as far as possible, thus improve the acoustically effective of full range.

Evaluation sound absorbent perforated structure to the acoustically effective of full range good and bad in, can average sound absorption coefficient be utilized with these two physical quantitys of frequency span △ f.Average sound absorption coefficient refers to the average of acoustical absorption coefficient in certain band limits.

$\stackrel{\‾}{\mathrm{\α}}=\frac{{\∫}_{f1}^{f2}\mathrm{\α}df}{f_2-f_1}---\left(2\right)$

Wherein f ₁and f ₂for bound frequency, can determine according to actual needs.The acoustically effective of acoustic absorbant in a certain band limits can be weighed with it.Band width is then the region between two and half resonant frequencies, is typically expressed as:

△f＝f ₂’-f ₁’(3)

Wherein f ₁' and f ₂' be respectively the frequency of acoustical absorption coefficient corresponding to maximal value one half and be called half resonant frequency.

But in order to easy directly from average sound absorption coefficient evaluate the acoustically effective of sound absorbent perforated structure to full range with while frequency span △ f two aspects, the utility model introduces a new physical quantity-absorption area S _{α f}, its expression formula is the product of average sound absorption coefficient and frequency span:

$S_{\mathrm{\α}f}=\stackrel{\‾}{\mathrm{\α}}\mathrm{\Δ}f---\left(4\right)$

It is the New Set that the utility model evaluates full-frequency sound absorption effect.

In the arrangement process of experimental result, find the acoustical absorption coefficient α <24% of all distribution situations corresponding to the frequency band of f>2500Hz that aperture is 2mm, 4mm, 8mm random combine, acoustical absorption coefficient is at this moment relatively low; In addition, all there is a resonance absorbing peak in their positions near f=500Hz, this absorption peak is caused by the resonance of plate itself, be not absorption peak caused by hole (experiment shows that imperforated system also exists a resonance absorbing peak departing from position near f=500Hz), and the α corresponding as f=1000Hz has dropped to less than 15%; Due to our research be the distribution of different pore size on the impact of perforated plate acoustically effective, the resonance therefore as far as possible will ignoring plate itself is to testing the impact brought, so this paper fixes on 1000-2500Hz within the scope of this full range in an experiment.The quality of the acoustically effective of all distribution situations of different pore size combination is compared in this frequency band of 1000-2500Hz.

Be under the condition of 1.39% in percentage of perforation, adopt cardboard material, thickness is 0.2cm, and middle folded air layer 0.33cm, the perforated plate of aperture 2mm, 4mm, 8mm various combination refers to Fig. 2 in the full-frequency sound absorption effect of full range 1000-2500Hz.

Shown many experiments data, by the various combination perforated plate hole area distribution of Fig. 3 aperture 2mm, 4mm, 8mm and the relation of absorption area, when the ratio that the perforation total area and aperture that we can find out when aperture is 2mm are the perforation total area of 4mm is about 3, combination perforated plate has maximum absorption area S _{α f}, the acoustically effective of full range is best.

Claims (6)

1. a combination perforated plate, it is characterized in that: comprise centre panel, described centre panel is provided with by the center of circle to extraradial perforation, described perforation distributes in the form of a ring, the air layer be made up of flexible pipe is provided with in described centre panel, described percentage of perforation is 1.39%, and aperture is the ratio that the perforation total area and the aperture of 2mm is the perforation total area of 4mm is 3.

2. a kind of combination perforated plate as claimed in claim 1, is characterized in that: described flexible pipe is for circle and diameter is 0.33cm.

3. a kind of combination perforated plate as claimed in claim 1, it is characterized in that: described centre panel both sides are provided with top panel and lower panel, described centre panel and top panel are equipped with some layers of pugging between centre panel and lower panel.

4. a kind of combination perforated plate as claimed in claim 3, is characterized in that: the packing material of the described pugging of some layers is glass wool, asbestos, porous foam, polyurethane sea or metal fibre.

5. a kind of combination perforated plate as claimed in claim 4, is characterized in that: centre panel all adopts aluminium material.

6. a kind of combination perforated plate as claimed in claim 3, is characterized in that: described top panel, lower panel all adopt the stainless steel that rotproofness is strong.