JPH07247605A - Sound-insulation panel - Google Patents

Abstract

PURPOSE:To improve a sound-insulating property in the frequency zone higher than 1KHz, by installing a sound-absorbing material in cells of honeycomb core plywood. CONSTITUTION:A surface layer material 1 of a surface side and a honeycomb core material 2 are extrusion molded from an aluminum alloy and a sound- absorbing material 5 is charged into the cells 4 of core material 2 from holes 3A of the surface layer material 3. Soft foam, after-foaming foam, glasswool, etc., are used as the sound-absorbing material 5. A facing material like polyvinyl chloride having 1kg/m<2> or higher plane density may be used as a surface layer material 3. In this way, sound-insulating function in a frequency zone higher than 1kHz can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound insulation panel using a honeycomb plywood having a honeycomb core.

[0002]

2. Description of the Related Art As a floor material for a conventional railway vehicle, a honeycomb core plywood made of an aluminum alloy has been used in consideration of its strength, sound insulation effect and lightness. In this, as shown in FIG. 8, the surface layer material 1 on the front surface side and the honeycomb core material 2 are manufactured from an aluminum alloy, and the surface layer material 3 made of an aluminum alloy is brazed to the back surface side. The cells 4 of the honeycomb core material 2 remain hollow. Back surface material 3
The hole 3A communicating with the cell 4 is opened in the
The presence of A can reduce the electromagnetic noise of 1 KHz to 1.2 KHz.

[0003]

In the conventional honeycomb core plywood, the sound transmission loss is 29.4d at a frequency of 1 KHz.
B, 27.6 dB at 1.25 KHz, 2 at 1.6 KHz
8.7 dB, 31.1 dB was measured at 2 KHz. The honeycomb core plywood used here is 928 x 877 (m
m), the thickness is 20 mm, the size between the opposite sides of the honeycomb cell 4 is 19.77 mm, and the surface materials 1 and 3 are both 2
The thing of mm was used.

[0004] Therefore, an object of the present invention is to provide a sound insulation panel having further improved sound insulation in a frequency region exceeding 1 KHz.

[0005]

In order to achieve the above object, the present invention has a sound absorbing material placed inside the cells of a honeycomb core plywood.

[0006]

[Function] In the case where every other sound absorbing material is inserted in the row direction of the cells of the honeycomb, it is 29.2d at 1.25 KHz.
B, 31.3 dB at 1.6 KHz, 33.3 at 2 KHz
Improvements in dB and sound insulation performance were observed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

In the first embodiment shown in FIG. 1, the surface layer material 1 on the surface side and the honeycomb core material 2 are extruded from an aluminum alloy in the same manner as in the prior art, and the surface layer material 3 is placed in the cells 4 of the core material 2. Hole 3
Sound absorbing material 5 is inserted from A. As the surface layer material 3 on the back surface, an aluminum alloy was brazed and attached. As the sound absorbing material 5, soft foam, post-foamed foam, glass wool, Fibrite (registered trademark) or the like can be preferably used. Here, fibrite (fiber bundle sound absorbing material) is a polyester fiber having a fiber diameter distribution center of 6 to 8 denier and an average length of 50 mm mixed with 20% by weight of a low melting polyester fiber having a denier of 4 mm and an average length of 50 mm. A fiber molded body having an apparent density of 0.07 g / cm ^{3 obtained} by filling the mold having air permeability after opening and blowing and molding with hot air at 150 ° C. to solidify. As a means for putting the sound absorbing material 5 into the cells 4 from the holes 3A of the surface layer material 3 on the back surface side, the post-foaming foam can be injected and foamed. In addition, holes are formed between the cells 4 so as to communicate with each other, and the sound absorbing material 5 is put in all the cells 4 by injecting the foaming undiluted solution through the holes 3A of the surface layer material 3 on the back surface side to foam. You can also In particular, railway vehicles running at high speed have problems such as aerodynamic noise (vehicle connection parts, pantographs, etc.), vibrations and noise when passing each other in tunnels, resonance due to the use of an AC motor, and vehicle interior noise. A noise expansion of 10 dB is measured in the tunnel, and the problem of sound insulation such as electromagnetic noise from under the floor is great. As a sound insulation panel used for the floor material of such a high-speed railway vehicle, as shown in FIG. 2, 928 × 877 (mm)
The honeycomb core material 2 as shown in FIG. 3 was sandwiched between the surface layer materials 1 and 3 by using the same size. In such a sound insulation panel as shown in FIGS. 2 and 3 (only the core material 2 is shown), the size between the opposite sides of the cells 4 of the honeycomb is set to 1
When the distance was 9.77 mm and the distance between the central portions of the adjacent cells 4 in one row was 32.7 mm, the sound absorbing material 5 was placed in every other cell 4 in each row and column.

A second embodiment shown in FIG. 4 shows a surface layer material 3 on the back surface side of the first embodiment to which a sound absorbing sheet 6 similar to the sound absorbing material 5 contained in the cell 4 is attached. The thickness of the sound absorbing sheet 6 is 5 mm or more, preferably 10 mm or more,
More preferably, it is 20 mm or more.

In the third embodiment shown in FIG. 5, a skin material 7 having an areal density of 1 kg / m ² or more is attached to the surface material 3. A polyvinyl chloride sheet can be suitably used as the skin material 7. The above areal density is preferably 2 kg / m ²
That is all.

The fourth embodiment shown in FIG. 6 is the second embodiment shown in FIG.
The sound absorbing sheet 6 of the embodiment with the skin material 7 attached is shown. The attachment positions of the sound absorbing sheet 6 and the skin material 7 may be reversed.

Skin material 7 used in the third and fourth embodiments.
When a polyvinyl chloride sheet is used as the
The areal density was set to 2 kg / m ² . Fibrite was used as the sound absorbing material 5, and was set to 0.07 g / cm ³ . The sound absorbing sheet 6 is also made of fibrite and has a thickness of 20 mm and is 0.07 g / cm ^3.
And

FIG. 7 is a graph showing the relationship between frequency and sound transmission loss. Reference symbol A indicates a conventional honeycomb core plywood made of aluminum alloy in which no sound absorbing material is placed in the cells 4, and reference symbol B indicates FIG. As shown, the sound absorbing material 5 was placed in every other cell 4 in each row, and fibrite was used as the sound absorbing material 5. Also, what is indicated by the symbol C is
In the second embodiment shown in FIG. 4, fibrite is used for the sound absorbing material 5 and the sound absorbing sheet 6, and the sound absorbing sheet 6 has a thickness of 2
It is 0 mm. The reference numeral D indicates the third embodiment shown in FIG. 5, and a vinyl chloride sheet (1 mm thick, 2 kg / m ² ) was used as the skin material 7. The reference numeral E represents the fourth embodiment shown in FIG. 6, and the same skin material as that shown by the reference numeral D was used. The fibrite used as the sound absorbing material 5 is 0.07 g in each case.
/ Cm ³ was used. As is clear from this graph, the code A is 27.6d at 1.25 KHz.
In contrast to B.B, those denoted by reference symbols B to E are 29.2 dB, 31.1 dB, 32.2 dB, 46.
It was 3 dB. At 1.6 KHz, the code A has a value of 28.7 dB, whereas the codes B to E have a value of 31.3 dB, 33.4 dB, 34.2 dB, and 4 respectively.
It was 9.1 dB. Further, at 2 KHz, what is indicated by the code A is 31.1 dB, whereas those indicated by the codes B to E are 33.3 dB, 36.7 dB, 36.
It was 5 dB and 51.3 dB. It can be seen that the sound insulation performance of the material indicated by the reference symbol E, that is, the material of the fourth embodiment, sharply improves from around 400 Hz.

[0014]

As described above, according to the present invention, since the sound absorbing material is put inside the cells of the honeycomb core plywood, the sound insulation performance is improved. Further, when the honeycomb core plywood is formed of aluminum or its alloy, it is effective in terms of strength and weight reduction. Further, the sound insulation performance was further improved in the case where a sound absorbing material was put inside the cell and a sound absorbing sheet or / and a skin material containing polyvinyl chloride was attached to the back surface side material.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a partially cutaway plan view showing a sound insulation panel for a high-speed railway vehicle.

FIG. 3 is a plan view of a core material.

FIG. 4 is a sectional view showing a second embodiment.

FIG. 5 is a sectional view showing a third embodiment.

FIG. 6 is a sectional view showing a fourth embodiment.

FIG. 7 is a graph showing the relationship between frequency and sound transmission loss.

FIG. 8 is a partially cutaway perspective view of a conventionally commonly used honeycomb core plywood.

[Explanation of symbols]

 1,3 Surface layer material 2 Core material 4 Cell 5 Sound absorbing material 6 Sound absorbing sheet 7 Skin material

Claims (3)

[Claims] 1. A sound insulation panel, characterized in that a sound absorbing material is put inside the cells of a honeycomb core plywood. 2. The sound insulation panel according to claim 1, wherein the honeycomb core plywood is formed of aluminum or its alloy. 3. A surface density of 1 kg / m containing a sound absorbing sheet and / or polyvinyl chloride as a surface layer material on the back surface of the honeycomb core plywood.
The sound insulation panel according to claim 1, wherein ^two or more skin materials are attached.