RU73003U1 - SOUND-ABSORBING PANEL - Google Patents

Abstract

The utility model relates to the field of manufacturing sound-absorbing structures and is designed to reduce indoor noise, as well as noise emitted by machines and mechanisms, and can improve sound absorption in a wide frequency range. The sound-absorbing panel contains perforated sheathing (5), continuous sheathing (6) and a multilayer breathable pleated aggregate located between them in the form of a zigzag corrugation, the layers of which (7, 8, 9) have the same relief geometry in plan and different heights of adjacent layers embedded by one on the other with the formation of air volumes between them. The increase in sound absorption efficiency is determined by the inclusion in the work of resonant volumes between the filler and both skins, the volumes formed between the filler layers, as well as energy losses during the transition of sound waves from a high density medium, which are layers of a filler, to a medium with a low density, which is air in volumes between aggregate layers, and in the reverse transition.

2 s.p. f-ly, 2 ill.

Description

The utility model relates to the field of manufacturing sound-absorbing structures and can be used in various industries, including engineering and construction, and is designed to reduce indoor noise, as well as noise emitted by machines and mechanisms.

A well-known sound-absorbing panel consisting of perforated and continuous skins and honeycomb core, the edges of which are located at an angle to the skins (US Patent No. 3821999, IPC G10K 11/172, 1974.07.02) - [1]. The disadvantage of this panel is the low manufacturability and relatively narrow range of sound absorption, determined by the height of the honeycomb block aggregate.

A sound-absorbing panel is known, consisting of thin-sheet skin and honeycomb belts spaced between them, made of corrugated ribbons, between which there are partitions in the form of thin sheets (US Patent No. 2870857, IPC EV 9/32, 1959.01.27) - [2]. The disadvantage of this panel is that it is quite difficult to manufacture and has a large specific gravity.

The closest to the claimed utility model is a sound-absorbing panel (Patent RU No. 2052604, IPC 6 Е04С 2/36, 1996.01.20) - [3], adopted as a prototype. It contains an upper perforated sheathing, a bottom continuous sheathing and a filler between them, made in the form of a zigzag corrugation, the tops of which are connected to these skins.

The disadvantage of this panel is that the sound absorption effect is provided only by Helmholtz cameras formed between the upper perforated casing and the filler. The cameras located between the lower casing and the filler are practically not involved in the work as resonating volumes, which reduces the efficiency of noise suppression and the frequency range of effective sound absorption.

The technical result, which is achieved by the claimed utility model, is to expand the frequency range of sound absorption and increase the sound absorption coefficient without reducing the manufacturability of the panel.

The technical result is achieved in that in a sound-absorbing panel containing perforated sheathing, continuous sheathing and a pleated aggregate between them, it is new that the aggregate is made of two or more layers of breathable folded structure having the same relief in plan and different heights of adjacent layers, nested one on top of another with the formation of air volumes between them. The aggregate layers have different air permeabilities. The layers of aggregate with distance from the perforated sheathing have a lower air permeability relative to each other.

The folded structure is understood as a relief surface made up of flat faces and unfolding on a plane without gaps and overlaps (V. Khaliulin. Technological schemes for manufacturing multilayer structures. Kazan: Kazan State Technical University, 1999, 186 pp.) - [ four].

The essence of the utility model is shown in figure 1 - figure 2, where:

figure 1 is a well-known sound-absorbing panel with a pleated aggregate in the form of a zigzag corrugation, where: a) a panel; b) sweep zigzag corrugation.

figure 2 - the claimed utility model, where: a) a panel with two layers of filler in the form of a zigzag corrugation; b) a panel with three layers of filler in the form of a zigzag corrugation; view A - side view of the panel with two layers of filler in the form of a zigzag corrugation; view B - side view of the panel with three layers of filler in the form of a zigzag corrugation.

Here: 1 - zigzag lines of the protrusions of the folded structure, 2 - zigzag lines of the depressions of the folded structure, 3 - sawtooth lines of the folded structure. All faces of 4 structures are the same. The sawtooth lines of the zigzag corrugation are located in the planes A _i perpendicular to the plane of the sheath B. Correspondingly, the faces are located symmetrically with respect to the planes. 5, 6 - perforated and continuous sheathing.

The filler layers in the form of a zigzag corrugation 7, 8 and 9 are located between the perforated 5 and the continuous 6 skin, have the same relief geometry in plan, but of different heights and are nested on top of each other until they come into contact along the zigzag lines of the protrusions and depressions with the formation of air volumes. Layers 7, 8 and 9 have different air permeability, and as they move away from the perforated casing 5, they have lower air permeability relative to each other.

The principle of operation of the panel is as follows:

- sound waves, penetrating through the holes of the perforated sheathing 5, are damped in the resonant volumes formed between the perforated sheathing 5 and the zigzag corrugation;

- due to the air permeability of the filler material, resonant volumes between the zigzag corrugation and the continuous casing 6 also participate in the absorption of sound waves;

- the volumes formed between the filler layers also participate in the work on the absorption of sound waves;

- when sound waves pass through multiple obstacles in the form of faces made of breathable material, the energy of sound is lost by friction;

- due to the formed air gaps between the filler layers 7, 8 and 9, when sound waves pass through the breathable material, energy is lost during the transition from a medium with a high density (filler material) to a medium with a low density (air volumes) and during the reverse transition;

- when the layers 7, 8 and 9 of the zigzag corrugation are arranged with a decrease in permeability from the perforated sheath 5 to the continuous sheath 6, the aggregate will have a variable impedance in height - the further from the perforated sheath, the greater the impedance. The small input impedance after perforated sheathing 5 will contribute to more efficient sound absorption.

The use of a utility model will improve the sound absorption efficiency in a wide frequency range.

Claims (3)

1. A sound-absorbing panel containing perforated sheathing, continuous sheathing and a folded structure aggregate between them, characterized in that the aggregate is made of two or more layers of breathable folded structure having the same relief in plan and different heights of adjacent layers embedded one on top of another to form air volumes between them. 2. The sound-absorbing panel according to claim 1, characterized in that the aggregate layers have different air permeability. 3. The sound-absorbing panel according to claim 1, characterized in that the layers of aggregate as they move away from the perforated sheathing have lower air permeability relative to each other.