JPS6362614B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to sound insulating building materials.

In general, sound-absorbing materials are constructed in the form of a sanderch between a pair of boards, or punching boards are used on the surface of the wall material to attenuate sound through the resonance effect of the holes, thereby increasing transmission loss. Something was warm. However, although the former is effective in the high frequency range, it has the disadvantage that it has little sound reduction effect in the midrange and low range, while the latter only increases transmission loss near the resonant frequency, and the hole size Due to the limited appearance, the resonant frequency could not be lowered to the lower range.

Therefore, an object of the present invention is to provide a sound-insulating building material that improves the sound-insulating effect and is easy to manufacture.

Figure 1 is a diagram showing the principle of a single expansion cavity type muffler, and the attenuation L〓 of this muffler is expressed by the formula: L〓=10・log [1+1/4 (m−1/m) ²・sin ² kl
] is given by. In the formula, m = S ₂ /S ₁ , S ₁ · S ₂ is the cross-sectional area of the cavity, k = ω / c = 2πf / c, ω is the angular frequency of the sound wave, c is the speed of sound, and f is the frequency of the sound wave. It is. Now, assuming m=16 and l=60, if we take a curve of the attenuation amount L (dB) against the frequency f (Hz), a curve as shown in FIG. 2 will be obtained. The curve at m=16 and l=90cm is shown in Figure 3. From these results, it can be seen that frequencies are attenuated except for some frequencies.

An embodiment of this invention is shown in FIGS. 4 and 5. In other words, this sound insulation building material has non-porous surface plates 2 and 3 placed on the front and back sides of a panel frame 1, and a sound insulation material is mounted inside.The sound insulation material is made of three punched boards. The punching boards 15 and 16 on both sides have holes 18 and 19 with the same diameter, respectively, but are formed at different positions vertically and horizontally (different centers), and the punching board 17 in the middle has holes with a larger diameter. Holes 20 with holes 20 are formed vertically and horizontally, and communicate with the holes 18 and 19 of both punching boards. According to this embodiment, the series of holes forms a kind of curved duct, which prevents the forward movement of the traveling plane wave, which has a sound damping effect, and also constitutes the single expansion cavity type muffler configuration, so that the formula It has a sound reduction effect based on , and exhibits sound insulation properties with both effects. Moreover, since the non-porous surface plates 2 and 3 are coated with the sound insulation material, it has an overall sound insulation effect.

As described above, the sound insulation building material of the present invention includes a first punching board in which first holes are formed vertically and horizontally;
a second punching board that is superimposed on the first punching board and has second holes formed vertically and horizontally so as to be out of position with respect to the first hole; and the first punching board and the second punching board. a third punching board interposed between the boards and having elongated holes vertically and horizontally formed to communicate with the first hole and the second hole, the outside of the first punching board and the second punching board; Since each of these is characterized by being covered with a non-porous surface plate, it has the following effects.

That is, the first punching board to the third punching board
Since the front and back sides of the laminate made of punched boards are covered with two non-porous surface plates, the two surface plates can achieve an overall sound insulation effect. Moreover, the first
The first hole, the second hole and the elongated hole of the punching board or the third punching board form a kind of bent duct to prevent the forward movement of the traveling plane wave. Due to the sound reduction effect due to the structure of the device, the sound insulation effect at the required frequency can be enhanced. Furthermore, since the first punching board to the third punching board are stacked on top of each other and the top plate is covered, manufacturing is easy.

[Brief explanation of drawings]

Figure 1 is a principle diagram of a single expansion cavity type muffler, Figure 2
3 and 3 are attenuation curve diagrams with respect to frequency, FIG. 4 is an exploded perspective view of an embodiment of the present invention, and FIG. 5 is a partial sectional view thereof. 2, 3... Surface plate, 15-17... Punching board, 18, 19... Hole, 20... Long hole.

Claims (1)

[Claims] 1. A first punching board with first holes formed vertically and horizontally, and a second punching board with second holes formed vertically and horizontally so as to be superimposed on the first punching board and shifted in position with respect to the first holes. 2 punching boards, the first punching board and the second punching board;
a third punching board interposed between the punching boards in which elongated holes communicating with the first hole and the second hole are formed vertically and horizontally, the first punching board and the second punching board A sound insulating building material characterized in that the outside of each is covered with a non-porous surface board.