JPH01189697A - Noise absorption equipment - Google Patents

Abstract

PURPOSE:To obtain the noise absorption equipment of large noise absorbing force to effectively cause diaphragm quantity to be small by causing a reinforcing material to be much more in a peripheral part in honey comb structure to be composed of a core, for which the reinforcing material is added in a core material, and the other core. CONSTITUTION:The diaphragm is caused to be the honey comb structure, for which skin materials 4a and 4b are fit to the both sides of a honey comb core material 4c and united. In this structure, a reinforcing material 7 is inserted only to a core 4d in an outer circumference part. The reinforcing material 7 is stretched in a core inside space with being obliquely inclined as being shown in a figure, for example. The quality of the material of the core material 4c is formed by a paper and synthetic resin, etc., in addition to aluminum and concerning the quality of the material of the skin material 4a and reinforcing material 7, the same formation is obtained. Thus, by arranging the core 4d, to which the reinforcing material 7 is inserted, in the outer circumference part where reaction is concentrated when bending force is added, bending rigidity is effectively made large and as a result, the diaphragm quantity can be made small to the bending rigidity. Then, the noise absorption equipment of large noise absorbing quantity can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a sound absorbing device.

[Conventional technology]

Conventionally, as shown in FIGS. 1 and 2, as a sound absorbing device, a diaphragm is inserted through an edge 5 into the opening 3 of an enclosure 1 having an opening 3 on one side and forming an air chamber 6 inside. 4 is provided so that it can vibrate freely. As shown in FIG. 3, such a sound absorbing device includes a diaphragm 4 integrated by sandwiching a honeycomb core material 4C made of paper, aluminum, etc. between thin film sheets 4a, 4b of aluminum or the like.
is used. In this sound absorbing device, a diaphragm 4 vibrates when a sound wave is incident, thereby consuming sound energy. As shown in FIG. 4, the sound absorption characteristic generally exhibits a chevron-shaped single resonance characteristic having the maximum sound absorption power at the resonance frequency fr. The graph shows sound absorption power on the vertical axis and frequency on the horizontal axis.

This sound absorbing device exhibits a greater sound absorbing force as the diaphragm 4 vibrates more easily, so the smaller the mass of the diaphragm 4, the easier it is to vibrate, and therefore a greater sound absorbing force can be obtained. Therefore, in order to increase the sound absorption power, the core 4d of the honeycomb core material 4c is made large, and the thickness of the honeycomb core material 4c (the distance between the skin materials 4a and 4b) is made small. If the thickness of the material 4C is reduced, the bending rigidity will be reduced, and the bending mode will be placed on the diaphragm 4, making it difficult to achieve single resonance, resulting in a problem in that the sound absorption power will be reduced.

[Problem to be solved by the invention]

The present invention has been made in view of the above points, and includes an enclosure having an opening on one side and forming an air chamber inside, a diaphragm disposed to close the opening of the enclosure, and In a sound absorbing device consisting of an edge disposed between an opening edge of an enclosure and a peripheral edge of a diaphragm and supporting the diaphragm so as to vibrate freely with respect to the enclosure, it is possible to effectively It is an object of the present invention to provide a sound absorption device with improved sound absorption efficiency by reducing the mass of a diaphragm.

[Means for Solving the Problems] The gist of the present invention is to provide an enclosure having an opening on one side and forming an air chamber inside, and a vibrator arranged to close the opening of the enclosure. In a sound absorbing device comprising a plate and an edge disposed between an opening edge of the enclosure and a peripheral edge of the diaphragm and supporting the diaphragm so as to vibrate freely with respect to the enclosure, the diaphragm is placed on both sides of a honeycomb core material. It has a honeycomb structure in which a skin material is attached and integrated, and the honeycomb core material is composed of cores with reinforcing material added to some parts and cores without reinforcing material, and the ratio of the cores with added reinforcing material is varied from the center of the honeycomb core material to the periphery. This is a sound absorbing device characterized by increasing the number of noises as they reach the lower part.

The present invention will be explained below with reference to drawings shown as examples.

Note that the configuration other than the diaphragm is the same as the conventional one, so the explanation will be omitted.

FIG. 5 is an exploded perspective view of the diaphragm 4 of the sound absorbing device according to one embodiment of the present invention. In the figure, 4 is a diaphragm, and skin materials 4a, 4b and a honeycomb core material 4c are formed from a reinforcing material 7.

In this embodiment, the reinforcing material 7 is inserted only in the core at the outer periphery. The reinforcing material 7 is stretched obliquely in the core inner space, as shown in FIG. 6, for example. The reinforcing material 7 is placed around the outer periphery where stress is concentrated when bending force is applied.
By arranging the core 4d containing 100 mm, the bending rigidity is effectively increased, and the diaphragm can be made lighter than a conventional diaphragm in which all the cores are made smaller in order to obtain the same bending rigidity. In this embodiment, the reinforcing materials 7 are all oriented in the same direction, but the direction is not particularly limited. In addition, from the viewpoint of bending rigidity, in the case of a honeycomb core like the one in this embodiment, as shown in FIG. 6, the core 4
It is effective to use the reinforcing material 7 as an inclined surface formed by four nodes that divide d into plane symmetry.

Further, it goes without saying that the material of the honeycomb core material 4C is made of paper, synthetic resin, etc. in addition to aluminum, and the same applies to the materials of the skin material 4a and the reinforcing material 7.

〔Effect of the invention〕

The present invention provides an enclosure having an opening on one side and forming an air chamber inside, a diaphragm disposed to close the opening surface of the enclosure, and an edge of the opening of the enclosure and a periphery of the diaphragm. In the sound absorbing device, the diaphragm has a honeycomb structure in which skin materials are attached to both sides of a honeycomb core material and integrated with the honeycomb core material, and It is characterized in that the core material is composed of cores to which reinforcing materials are added and cores to which no reinforcing materials are added, and the proportion of the cores to which reinforcing materials are added increases from the center of the honeycomb core material to the periphery. The mass of the diaphragm can be reduced relative to the bending rigidity of the diaphragm, and a sound absorbing device with high sound absorption power can be provided.

[Brief explanation of the drawings] Part 1 is a perspective view of a conventional sound absorbing device, Figure 2 is a sectional view of the same as above, Figure 3 is an exploded perspective view of the diaphragm of same as above, and Figure 4 shows the sound absorption characteristics of same as above. FIG. 5 is an exploded perspective view of a diaphragm according to an embodiment of the present invention, and FIG. 6 is an enlarged perspective view of a main part thereof. 1, enclosure 2, baffle plate 3, opening 4a, skin material 4, diaphragm 4b, skin material 5, edge 4c, honeycomb core material 6, air chamber 4d, core 7, reinforcing material

Claims (2)

[Claims] (1) An enclosure having an opening on one side and forming an air chamber inside, a diaphragm arranged to close the opening surface of the enclosure, and an edge of the opening of the enclosure and a periphery of the diaphragm. In a sound absorbing device, the diaphragm has a honeycomb structure in which skin materials are attached to both sides of a honeycomb core material and integrated with the honeycomb core material, and A sound absorbing device characterized in that the honeycomb core material is made up of a core partially added with a reinforcing material and a core without a reinforcing material, and the proportion of the core added with the reinforcing material increases from the center of the honeycomb core material to the periphery. . (2) The sound absorbing device according to item 1, wherein the reinforcing material is installed obliquely within the core.