JP2555779Y2 - Rock wool molded sound absorbing plate - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rock wool molded sound absorbing plate.

[0002]

2. Description of the Related Art Conventional rock wool-molded sound-absorbing plates include those having irregularly shaped concave grooves called so-called insect eating on the surface and those having regularly formed sound-absorbing holes called pin holes. However, even after the worm biting and pin hole processing, the sound absorbing characteristics of the rock wool-molded sound absorbing plate are inferior to sound absorbing materials such as glass wool.

[0003]

The present invention is based on the premise that the simplest pin hole processing is performed, and specifies the processing conditions such as the hole diameter, the hole depth, the number of holes, etc., so as to meet the target frequency range. It is an object of the present invention to provide a rock wool molded sound absorbing plate having optimal sound absorbing characteristics.

[0004]

Means for Solving the Problems As means for technically solving the above-mentioned problems, the present invention is a sound absorbing plate having a sound absorbing hole formed in a rock wool molding plate, and the diameter of the sound absorbing hole is 1 mm to 1 mm.
The gist is 2 mm, the depth of the hole is a non-through hole of 5 mm to 10 mm, and the number of holes is 5 mm to 6 mm at the hole pitch.

[0005]

[Operation] By specifying the diameter, depth, number and the like of the sound absorbing holes as described above, a rock wool molded sound absorbing plate having better sound absorbing characteristics than the conventional rock wool molded sound absorbing plate can be formed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, a sound absorption test was conducted to examine the relationship between the sound absorption holes provided in the rock wool molded sound absorption plate and the sound absorption coefficient. [First Test] As shown in FIGS. 1 (a) and 1 (b), a disk-shaped test piece 1 having a diameter of 91.6 mm was formed from a 15.0 mm-thick rock wool molded plate. The normal incidence sound absorption coefficient test was performed by providing pin holes 2 having different hole diameters. The diameter of the pin hole 2 is
As shown in FIG. 2, there are three types: 1 mm, 2 mm, and 3 mm. As a common condition, the number of pin holes is 5.6 m in hole pitch.
m, and the pin hole depth was 7.5 mm in each case.

FIG. 3 shows the results of the first test.
When the center frequency is 500 Hz or less, there is almost no difference in sound absorption due to the difference in pin hole diameter. However, when the center frequency exceeds 500 Hz, a difference in sound absorption appears, and the one having a pin hole diameter of 1 mm has a high sound absorption. However, in the range of about 1300 Hz to 1700 Hz, the pin hole diameter of 2 mm shows the highest value, and the pin hole diameter of 3 m
In the case of m, the sound absorption coefficient was the lowest over the entire range irrespective of the magnitude of the frequency.

[Second Test] Next, in order to examine the relationship between the depth of the pin hole and the sound absorption coefficient, the disk-shaped test piece 1 was formed and, as shown in FIG. 0.5 mm, 10 mm, and 15 mm (that is, through holes). As common conditions, the pin hole diameter was set to 2 mm and the hole pitch was set to 5.6 mm.

FIG. 5 shows the results of the second test. When the center frequency is about 850 Hz or less, the pin hole depth of 5 mm has a high sound absorption coefficient, and as the hole becomes deeper, the sound absorption coefficient decreases. Showed the lowest value. However, 85
When the frequency exceeds 0 Hz, a reversal phenomenon occurs and the pin hole depth of 5 mm has a low sound absorption coefficient, and the sound absorption coefficient increases as the hole becomes deeper,
In the range of 1300 Hz to 2000 Hz, the through hole showed the highest value. However, when the frequency exceeded 2,000 Hz, the sound absorption coefficient of the through-hole fell sharply, and reached the lowest value at 4000 Hz.

[Third Test Part (1)] Next, the relationship between the number of pin holes and the sound absorption coefficient was examined. Three tests were performed by changing the pin hole diameter and the pin hole depth. That
(1) shows that the test piece 1 is formed as shown in FIG. 6 and the pin hole diameter is 2 m as a common condition of (a) to (c).
m, the pin hole depth was 5 mm, (a) the number of pin holes was 8 mm in hole pitch, (b) was 5.6 mm, and (c) was 4 mm.

FIG. 7 shows the results of the third test (1).
mm, the hole pitch of 8 mm showed a low sound absorption when the frequency exceeded 1000 Hz.

[Third Test Part (2)] FIG. 8 shows a third test part (2). The common conditions of (a) to (c) are that the pin hole diameter is 2 mm and the pin hole depth is 2 mm. Are 7.5mm, and (a) is the hole pitch of the number of pin holes 8mm,
(B) is a hole pitch of 6.5 mm, (C) is a hole pitch of 5.6 mm
And

FIG. 9 shows the results of the third test (2). When the center frequency exceeded 2,000 Hz, the hole pitch of 5.6 mm showed a remarkably high sound absorption coefficient.

[Third Test No. (3)] FIG. 10 shows a third test No. (3). As common conditions of (a) to (c), the pin hole diameter is 1 mm and the pin hole depth is 1 mm. Are all 10 mm, (a) is the hole pitch of the number of pin holes 8 mm,
(B) has a hole pitch of 5.6 mm, and (C) has a hole pitch of 4 mm.

FIG. 11 shows the test results of the third test (3). When the center frequency is 500 Hz or less, the hole pitch of 8 mm has a high sound absorption coefficient, and as the pitch decreases, the sound absorption coefficient decreases, and the hole pitch decreases. 4 mm showed the lowest value.
However, when the frequency exceeded about 850 Hz, a reversal phenomenon occurred, and the sound absorption rate was low when the hole pitch was 8 mm, and the sound absorption rate increased as the pitch increased, and the hole pitch of 4 mm showed the highest value.

Considering the above test results, the optimum conditions of the sound absorbing hole to be formed in the rock wool molding plate are that the hole diameter is 1-2 mm from the first test, and the depth of the hole is the second test. From 5
10 to 10 mm non-through hole, the number of holes is 5
mm to 6 mm, respectively.

The hole pattern does not necessarily need to be provided regularly on the entire surface of the plate. If a predetermined number of holes is satisfied, the hole processing portion P is limited to a half area of the plate as shown in FIG. It has also been found that it is possible to form the hole by appropriately incorporating design elements, for example, as shown in FIG.

Further, the type of the holes is not limited to one type. For example, two types of holes A and B having different sizes as shown in FIG.
May be alternately arranged. In this case, the hole A has a diameter of 2 mm and a hole depth of 7.5 mm (the thickness of the formed plate is 15 mm), the hole B has a diameter of 1 mm and the same hole depth of 7.5 mm, and a hole pitch R of 5.5 mm. , The hole pitch S is 5.5 mm, and the hole pitch T is 2.75 mm.

[0019]

[Effects of the Invention] As described above, according to the present invention,
Since the formation conditions such as the hole diameter, hole depth, and number of holes for the sound absorbing holes in the rock wool molded sound absorbing plate have been specified, optimal sound absorbing characteristics can be given according to the target frequency range. This has the effect of exhibiting sound absorption performance far superior to that of a molded sound absorption plate.

[Brief description of the drawings]

FIG. 1 shows a specimen for performing a normal incidence sound absorption coefficient test of a rock wool molded sound absorbing plate, wherein (a) is a front view and (b) is a side view.

FIGS. 2A to 2C are explanatory diagrams showing hole diameters of a test body, respectively.

FIG. 3 is a graph showing the results of a sound absorption coefficient test based on hole diameter comparison.

FIGS. 4A to 4D are explanatory diagrams respectively showing the hole depths of the test specimen.

FIG. 5 is a graph showing the results of a sound absorption test by comparing hole depths.

FIGS. 6A to 6C are explanatory diagrams showing the number of holes in a test body, respectively.

FIG. 7 is a graph showing the results of a sound absorption coefficient test based on a comparison of the number of holes (No. 1).

FIGS. 8A to 8C are explanatory diagrams showing the number of holes in a test body, respectively.

FIG. 9 is a graph showing a sound absorption coefficient test result based on a comparison of the number of holes (No. 2).

FIGS. 10A to 10C are explanatory diagrams showing the number of holes in a test body, respectively.

FIG. 11 is a graph showing the results of a sound absorption coefficient test based on a comparison of the number of holes (part 3).

FIGS. 12A and 12B are explanatory diagrams respectively showing examples of patterns for drilling holes in a part of a plate.

FIG. 13 is an explanatory diagram showing an embodiment in which two types of holes are used.

[Explanation of symbols]

1: Specimen 2: Pin hole P, Q: Hole processing part
R, S, T: Hole pitch

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-60-105630 (JP, A) JP-A 62-38306 (JP, U) JP-A 59-69316 (JP, U) JP-A Sho 56- 151417 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A sound-absorbing plate having a sound-absorbing hole formed in a rock wool molded plate, wherein the diameter of the sound-absorbing hole is 1 mm to 2 mm, the depth of the hole is 5 mm to 10 mm, and the number of holes is A rock wool molded sound absorbing plate characterized in that the pitch is 5 mm to 6 mm.