RU2547519C1 - Kochetov's acoustic absorber of combined type - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: sound absorber of combined type contains sound absorbers of active and reactive types located on rigid framework, framework is out of two parts, at that bottom part, i.e. reactive part, is made as rigid hollow cylinder, its bottom is connected with a support disk connecting it with a support disk on which via the resilient dampening element a top part of the framework is installed, it is made as rigid perforated cylindrical shell with perforated cover and solid base connected with the support disk, the cylindrical shell cavity is filled with sound-absorbing material, and the top and the bottom parts are connected by means of the resilient dampening element ensuring dampening of HF oscillations; at that to the perforate cover of the cylindrical shell the element is hingedly connected, using this element the framework is secured to the required object, for example, ceiling of the production room, and around the rigid perforated cylindrical shell at least one helical sound-absorbing element is installed made as cylindrical screw spring enclosing it and resting against the support disk; at that the cylinder cavity of the framework reactive part is tightly covered by the support disk with at least one hole functioning as mouth of Helmholtz resonator, that is crated together with the cylinder cavity, and around the hollow cylinder at least one helical sound-absorbing element is installed, that is made as cylindrical screw spring enclosing the hollow cylinder and resting against the support disks.

EFFECT: improved efficiency of noise suppression at high frequencies.

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Description

The invention relates to noise reduction in industrial and transport facilities.

Known designs of piece sound absorbers made in the form of volumetric parallelepipeds, cubic, conical, the cavities of which are filled with sound-absorbing material [1, 2, 3, 4]. Currently, fibrous sound absorbers are the most common in construction practice.

The disadvantages of the known piece sound absorbers are the relatively low efficiency at low and medium frequencies, and they do not meet the increased requirements for room design.

Known conical piece sound absorber according to the patent of the Russian Federation No. 22822004 [5], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with sound-absorbing material located inside the frame wrapped with mesh nylon fabric, the frame is made in the form of a cone attached to it the lower flange with a hemisphere also containing sound-absorbing material wrapped in a mesh nylon fabric or fiberglass, and filling with sound-absorbing material can be as with air cavities and located on the periphery of the hemisphere, as well as within it in a checkerboard pattern on the three coordinate planes.

Its disadvantage is the relatively low efficiency of sound attenuation at high frequencies due to the lack of sound-reflecting layers that perform sound insulation functions at high frequencies.

Known cylindrical resonant piece sound absorber according to the patent of the Russian Federation No. 23033679 [6], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped in a mesh nylon fabric, the frame is made cylindrical in the form of a perforated round glass and lids, inside of which is located a central rod rigidly fixed to the axis of the glass, on which round partitions are mounted with the possibility of their fixation, inside one of which is a sound-absorbing material wrapped in a mesh nylon fabric.

The disadvantage is the relatively low noise attenuation efficiency at low frequencies due to the cramped dimensions for placing resonant cameras.

Known cubic piece sound absorber according to the patent of the Russian Federation No. 2334062 [7], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped with mesh nylon fabric, the frame is made in the form of two cubic surfaces, one of which - external - is perforated, and the other - internal - is acoustically transparent, and the sound-absorbing material wrapped in a mesh nylon fabric is located in the gap between the frame s, which are interconnected by means of resonance inserts of different diameters, and the inner cavity is divided by a partition into two resonant cavities, one of which is filled with a sound absorber.

The disadvantage is the relatively low efficiency of sound attenuation at high frequencies due to the lack of sound-reflecting layers that perform the functions of sound insulation at high frequencies.

Known volumetric piece sound absorbers according to the patent of the Russian Federation No. 2354786 [8] and the Russian Federation No. 2485256 [9], consisting of a rigid frame suspended on a fastener to the ceiling of the industrial building, the frame is made with sound-absorbing material wrapped in an acoustically transparent material.

Their disadvantage is the relatively low noise attenuation efficiency at high frequencies due to the lack of Helmholtz resonators.

The closest technical solution in terms of technical nature and the achieved result is a piece sound absorber according to the patent of the Russian Federation No. 2485256 [10], containing a rigid perforated frame, inside which a sound-absorbing material is placed, the frame is made of the lower part of the conical shape with a cover and the upper part of the cylindrical shape, which is attached to the cover of the lower part of the perforated frame by means of a vibration damping pad, which allows damping high-frequency vibrations, while to the upper part is cylindrical about the perforated carcass, an element is pivotally fixed by means of which the carcass is attached to the desired object, for example, the ceiling of the production room, and the cavities of the lower and upper parts of the perforated carcass are filled with sound-absorbing materials of different densities, with at least one around the upper part of the cylindrical a screw sound-absorbing element of a piece absorber, made in the form of a cylindrical helical spring from a dense non-combustible sound-absorbing th material.

The disadvantages of this piece of sound absorber is the relatively low noise reduction efficiency at low and medium frequencies due to the lack of volume cavities for Helmholtz resonators and cavities filled with a sound absorber, i.e. absorbers of various densities.

EFFECT: increased efficiency of sound attenuation at high frequencies by introducing volume cavities for Helmholtz resonators into a piece sound absorber, which increase efficiency at high frequencies.

This is achieved by the fact that in a combined type sound absorber containing active and reactive type sound absorbers placed on a rigid frame, the frame consists of two parts, while the lower, reactive part is made in the form of a rigid hollow cylinder, the bottom of which is connected to a support disk connecting it with a support disk, on which the upper part of the frame is fixed through an elastic damping element, which is made in the form of a rigid perforated cylindrical shell with a perforated cover and a solid base With a connection to the support disk, the cavity of the cylindrical shell is filled with sound-absorbing material, and the upper and lower parts are connected by means of an elastic damping element that allows damping high-frequency vibrations, while the element is pivotally fixed to the perforated cover of the perforated cylindrical shell by means of which the frame is attached to the desired object , for example, the ceiling of the production room, and around a rigid perforated cylindrical shell located at at least one, a screw sound-absorbing element made in the form of a cylindrical coil spring, covering it, and resting on a support disk, and the cylinder cavity of the reactive part of the frame is hermetically closed by a support disk with at least one hole that serves as the neck of the Helmholtz resonator, which is formed together with the cylinder cavity, and around the hollow cylinder there is at least one screw sound-absorbing element, made in the form of a coil spring, vayuschey hollow cylinder, and rests on the support wheels.

The drawing shows a diagram of a sound absorber of a combined type.

The sound absorber of the combined type contains sound absorbers of the active and reactive types located on the rigid frame 1. The frame 1 consists of two parts, while the lower, reactive, part 7 is made in the form of a rigid hollow cylinder 8, the bottom of which is connected to the supporting disk 11, connecting it to supporting disk 6, on which the upper part 2 of the frame 1 is fixed through an elastic damping element 5.

The upper, active, part 2 is made in the form of a rigid perforated cylindrical shell with a perforated lid and a solid base connected to the supporting disk 6. The cavity of the cylindrical shell is filled with sound-absorbing material, and the connection of the upper and lower parts is made by means of an elastic damping element 5, which allows damping high-frequency vibrations. At the same time, an element is pivotally fixed to the perforated cover of the perforated cylindrical shell by means of which the frame is attached to the desired object, for example, the ceiling of the production room. Around the rigid perforated cylindrical shell is located at least one screw sound-absorbing element 3, made in the form of a cylindrical helical spring, covering it, and resting on the supporting disk 6.

The cavity of the cylinder 8 of the reactive part of the frame is hermetically closed by a supporting disk 10 with at least one hole 9, which serves as the neck of the Helmholtz resonator, which is formed together with the cavity of the cylinder 8. Around the hollow cylinder 8 is located at least one screw sound-absorbing element 4 made in the form of a cylindrical coil spring, covering the hollow cylinder 8, and abutting against the supporting discs 10 and 11.

The screw sound-absorbing element 3 can be made in the form of a hollow screw sound-absorbing element formed by the external and internal screw surfaces forming a cavity, while the space formed by the external and internal screw surfaces is filled with sound-absorbing material with a density lower than that of the screw sound-absorbing element.

The sound absorber of the combined type operates as follows.

Sound waves propagating at an industrial or transport facility interact with sound-absorbing material located in the cavity of the perforated cylindrical shell of the active part 2 of the frame 1, as well as with screw sound-absorbing elements 3 and 4 located in the upper, active, part 2 and lower, reactive, part 7, suppressing noise at medium and high frequencies, respectively.

The connection of the upper 2 and lower 7 parts of the frame by means of an elastic damping element 5, allows you to damp high-frequency vibrations that can be emitted by a rigid frame, which allows it to be used to reduce noise on transport objects. Sound absorption at medium and high frequencies occurs due to the acoustic effect built on the principle of Helmholtz resonators, formed by the air cavity of cylinder 8 with a hole 9, which serves as the neck of the Helmholtz resonator. Moreover, to suppress sound vibrations in the required sound frequency range, as a rule, this is done: large volumes of the cavity of the cylinder 8 are used to suppress noise in the low frequency range, and small ones in the medium and high frequencies. The interaction of sound waves with screw sound absorbing elements 3 and 4 leads to additional sound attenuation in the high frequency range, and the implementation of a sound absorber from non-combustible materials makes the design fireproof.

Information sources

1. Kochetov O.S., Sazhin B.S. Noise and vibration reduction in production: theory, calculation, technical solutions. M .: MSTU im. A.N. Kosygina, 2001 .-- 319 p. (Fig. P. III. 10, p. 263).

2. Kochetov O.S. Textile vibroacoustics. Textbook for universities. M .: MSTU im. A.N. Kosygina, the group "Sovezh Bevo", 2003. - 191 p. (Fig. A.2, p. 176).

3. Kochetov OS Laboratory workshop on industrial sanitation. Textbook for universities. M .: MSTU im. A.N. Kosygina, “Sovezh Bevo” group, 2004. - 168 p. (Fig.6.6, p. 120).

4. Kochetov O.S. Sound-absorbing structures to reduce noise in the workplace of industrial premises. The journal "Labor safety in industry", No. 11, 2010, pp. 46-50 (Fig. 1; p. 48 and Fig. 2; p. 48).

5. Kochetov O.S., Kochetova M.O., Khodakova T.D., Damn A.M. Conical piece sound absorber // Patent for invention No. 2282004. Published on August 20, 2006. Bulletin of inventions No. 23.

6. Kochetov O.S., Kochetova M.O., Khodakova T.D. Cylindrical resonant piece sound absorber // Patent for invention No. 2303679. Published on July 27th, 2007. Bulletin of inventions No. 21.

7. Kochetov O.S., Kochetova M.O., Khodakova T.D. Cubic piece sound absorber // Patent for invention No. 2334062. Published on September 20, 2008. Bulletin of inventions No. 26.

8. Kochetov O.S., Kochetova M.O., Kochetov S.S., Kochetov Sergey Sergeevich. Volumetric piece sound absorber // Patent for invention No. 2354786. Published on May 10th, 2009. Bulletin of inventions No. 13.

9. Kochetov O.S. Piece sound absorber // Patent for invention No. 2485256. Published 06/20/2013. Bulletin of inventions No. 17.

10. Kochetov O.S., Stareeva M.O. Piece sound absorber // RF patent for the invention No. 2495202. Published 10/10/2013. Bulletin of inventions No. 28.

Claims (2)

1. A sound absorber of a combined type containing active and reactive sound absorbers placed on a rigid frame, characterized in that the frame consists of two parts, the lower, reactive part being made in the form of a rigid hollow cylinder, the bottom of which is connected to a support disk that binds it with a support disk on which the upper part of the frame is fixed through an elastic damping element, which is made in the form of a rigid perforated cylindrical shell with a perforated cover and a solid base connected to the support disk, the cavity of the cylindrical shell is filled with sound-absorbing material, and the connection of the upper and lower parts is made by means of an elastic damping element that allows damping high-frequency vibrations, while the element is pivotally fixed to the perforated cover of the perforated cylindrical shell by which the frame is attached to the desired object, for example, the ceiling of the production room, and around at least a perforated rigid cylindrical shell one, a screw sound-absorbing element made in the form of a cylindrical coil spring, covering it, and resting on a support disk, the cylinder cavity of the reactive part of the frame being hermetically closed by a support disk with at least one hole that serves as the neck of the Helmholtz resonator, which is formed together with the cylinder cavity, and around the hollow cylinder there is at least one screw sound-absorbing element made in the form of a cylindrical coil spring, covering hollow cylinder, and abuts against the supporting discs. 2. The combined type 3 sound absorber according to claim 1, characterized in that the screw sound-absorbing elements are made in the form of hollow sound-absorbing screw elements formed by external and internal screw surfaces forming a cavity, while the space formed by the external and internal screw surfaces is filled with sound-absorbing material with density less than that of a screw sound-absorbing element.

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