SU1463883A1 - Three-dimensional acoustic component - Google Patents

Abstract

The invention relates to noise control and can be used to reduce noise in workshops of industrial enterprises. The purpose of the invention is to provide the possibility of controlling sound absorption at low frequencies. For this, the acoustic volume element is made of fixed 1 and movable 2 cylindrical or prismatic shells, facing by concavity towards each other and connected with the possibility of adjusting their mutual position to change the size of the gap between their edges and the internal volume. The shells 1 and 2 consist of the inner 4 and outer 5 layers of sound-permeable material stretched over the frame longitudinal elements in the form of tubes 6 with slots on the outer side, and the sound-absorbing material placed between them. The ends of the acoustic surround element are closed by two thin diaphragms of composite fiber material, playing the role of membrane sound suppressors. The shells actively absorb the sound waves of medium and high frequencies, and the cavity bounded by them together with the slit forms a tunable low-frequency sound absorber, 2 Cp. f-ly, 7 ill. (Q CL 4 a co with CX5 co

Description

1

The invention relates to the field of noise control and can be used to reduce noise in the shops of industrial enterprises.

The purpose of the invention is to provide the possibility of controlled sound absorption at low frequencies.

FIG. Figure 1 shows an acoustic volume element, vsch (laterally, longitudinal section; Fig. 2 is view A in Fig. 1; Fig. 3 is section B-B in Fig. 1; Fig. A is node I in Fig. 3; Fig. 5-7 shows the formation schemes and the settings of the acoustic volume elements.

Acoustic surround element consists of sound absorbers 1 and 2; made in the form of cylindrical silt of prismatic shells facing inwardly towards each other, and an element 3 of the connection, which makes it possible to regulate them; Sound absorbers j 1 and 2 are limited by the inner A and outer 5 layers of sound-absorbing material implanted on the frame longitudinal elements in the form of pipes 6, between which the sound-absorbing material 7 is placed. Between the edges of the shells

slot 8 is formed. Cuts 9 are made on the outer surface of pipes 6, connecting them to the surrounding cavity: -environment. The ends of the volume element are closed by thin diaphragms 10 and 11 of the composite fiber material forming membrane absorbers. The volume element is provided with loops 12 for suspending it from the carriers.

designs m.

Acoustic volume element works as follows.

Shells of sound absorbers wrapped in sound-transparent material actively absorb sound waves of medium and high frequencies.

The end diaphragms, which play the role of membrane sound absorbers, absorb sound waves, mainly in the mid-frequency region, where, as. as a rule, the maximum emitted by the process equipment is observed. The expansion of the diaphragms of the composite fiber material leads to an intense damping of their vibrations and, as a result, to an expansion of the frequency range of active sound absorption.

The shells with gaps between their edges and the device for adjustment and interposition form a tunable low-frequency sound absorber, and the frame elements play the role of resonant sound absorbers on medium and high frequencies, depending on the size of pipes and slots.

Thus, the acoustic surround element absorbs sound in a wide frequency range. The bulk element is best made from a composite fiber material such as fiberglass, known methods of automated winding, since the latter has a relatively low weight, high strength and chemically resistant.

The use of a sound absorber of this design will increase its selectivity and efficiency in a wide range and allows its use in chemically active media.

Formula and

acquisitions

Claims (3)

I. Acoustic volume element, which includes sound absorbers wrapped in sound-permeable material, located with the formation of a gap between them, the elements of the connection and. end diaphragms, characterized in that, in order to be able to control sound absorption in the low frequency range, sound absorbers are made in the form of cylindrical fittings of prismatic shells facing one another towards the concavity, and elements of their connection with the possibility of adjusting the relative position of the shells. 2. An element according to p .1, about tl and h ai y and with the fact that the end diaphragms are made of. composite fibrous material with the formation of membrane sound absorbers. 3. An element according to claim 1, of which is that the sound absorbers are made with frame longitudinal elements in the form of pipes with slots on the outer surface connecting their cavities with the environment, and the sound-permeable material is nat chickpeas on frame elements .View eleven b b FIG. 2 Fi.N Fi.Z FIG. five 6 FIG. 7