JP2960402B1 - Lightweight high rigidity panel - Google Patents

Abstract

[PROBLEMS] Although there is a plate structure in which a concave or convex groove is provided only in one direction of the plate thickness, since the flat surface is wide, the local rigidity at that portion is weak, which may cause noise. The effect of suppressing vibrations with high frequencies and small wavelengths is small. SOLUTION: In two directions of the vertical and horizontal direction of the flat panel, and
The unevenness is provided on both sides of the panel. As a result, even with the same plate thickness, the bending rigidity can be increased, vibration can be reduced, and as a result, noise can be reduced. In this case, if the irregularities are provided in a staggered manner so that flat portions other than the irregularities are not formed linearly, a straight vibration node cannot be formed, so that the natural frequency of the panel increases and the vibration damping property is increased. Is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The invention according to the present invention relates to an interior panel of a vehicle or an architectural structure which is locally uneven in two directions of thickness, thereby increasing bending rigidity even with the same thickness, thereby reducing vibration. The present invention relates to a lightweight high-rigidity panel for reducing noise.

[0002]

2. Description of the Related Art Spaces where people live, such as railway vehicles, automobiles (hereinafter referred to as "vehicles"), aircraft, ships, and other transport machines, and building structures, have interior panels on the wall surfaces. This interior panel is an important material that determines the noise level in a car or a room.To reduce noise, it is better to make it heavy or increase its rigidity. It cannot be made large, and it is required to reduce the weight as much as possible.

Hitherto, corrugated sheets provided with irregularities in only one direction to increase rigidity have been known, and are widely used in vehicles and building structures (for example, Japanese Patent Publication No. 1-4870,
JP-A-4-336239).

[0004]

When a corrugated plate is provided with irregularities in only one direction, rigidity in a direction perpendicular to the corrugated plate is weak, and the range of the strength member is limited.

[0005] There is a plate structure in which a concave or convex groove is provided only in one direction of the plate thickness. However, since the flat surface is wide, the local rigidity at that portion is weak, and a frequency which may cause noise is low. The effect of suppressing high and small wavelength vibrations is small.

[0006] Further, from the viewpoint of low vibration and low noise, there is no panel whose shape is changed to increase rigidity without changing the thickness of the panel.

In the invention according to this application, the plate is locally made uneven in the thickness direction to increase the bending rigidity even with the same thickness,
It is an object of the present invention to provide a lightweight high-rigidity panel that can reduce vibration and consequently reduce noise.

[0008]

In order to solve the above problems BRIEF SUMMARY OF THE INVENTION, lightweight rigid panels according to the claimed invention is one
Unevenness is provided in both the vertical and horizontal directions of the flat panel and the both sides of the panel, and a flat portion other than the unevenness is provided.
Minutes are not formed linearly in any direction
Are provided so as to be close to the irregularities in a staggered manner . As a result, even with the same plate thickness, the bending rigidity can be increased, vibration can be reduced, and as a result, noise can be reduced.

Moreover , in this case, since the uneven portions are provided in a staggered manner so as to prevent the flat portions other than the uneven portions from being formed linearly, a straight vibration node is not formed.
Since there is no panel, the natural frequency of the panel increases, and the damping performance is enhanced. If the irregularities are circular, polygonal, or rectangular, the production becomes easier. In addition, if a virtual equilateral triangle having common vertices is drawn on the flat panel and concaves or convexes are provided at the respective vertices and the irregularities are arranged in a staggered manner, the flat portions are not formed linearly, and the flat portions are not formed. A vibration damping panel having excellent vibration performance can be obtained.

Another lightweight high-rigidity panel is a single panel formed by laminating and bonding two perforated plates having a large number of holes in a staggered manner with the positions of the holes shifted. Form irregularities on both sides with the above holes and other parts, and
The flat part other than this unevenness is straight in any direction
The irregularities are provided close to each other so as not to be formed . That is, the two perforated plates have a structure in which the holes are shifted and overlapped, and when joined, the holes are arranged so that one of the holes forms the above-described recess (convex when viewed from the opposite surface). As a result, a similar increase in the natural frequency
In addition to the function and effect, when the weight is reduced by the weight of the hole and the weight is kept constant, the thickness of the plate is increased by the amount of the hole to increase rigidity.

In this case, by mounting a vibration damping material between two perforated plates at the stage of manufacturing the panel, a panel having high rigidity and improved vibration damping properties can be obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view of a first embodiment of a lightweight high-rigidity panel embodying the idea of the present invention,
FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2 (a) is a partially enlarged plan view of FIG. 1 (a), and FIG.
3 is a sectional view taken along the line BB in FIG.

A large number of circular irregularities are arranged in a zigzag pattern on both sides of a thin flat panel 1. That is, panel 1
A number of virtually drawn equilateral triangles t with common vertices on top
A group of circular concave portions 2 (convex portions as viewed from the rear surface) having centers at respective vertices 1 to tn is provided, and circular convex portions 3 (represented by solid lines for convenience, concave portions as viewed from the rear surface) are provided between the two concave portions. ) The groups are likewise arranged in a staggered manner.

The concave portion 2 or the convex portion 3 is provided in two in-plane directions. That is, three groups of convex portions arranged in the horizontal direction, that is, the directions of the H1 to Hn lines, and the vertical directions L1 to L orthogonal to the three groups.
In addition to the three groups of protrusions provided in the n-line direction, the second group of recesses are similarly provided in two directions.

The concavo-convex portion comprises a convex portion 3 formed when a circular bowl dish is turned down, and a concave portion 2 opposite thereto. The reason why the unevenness is formed in two directions in the plane is to increase rigidity in two directions and eliminate anisotropy like a corrugated plate to increase rigidity against vibrations in various directions.

As shown in FIG. 2A, the reason why the circular concave and convex portions 2 and 3 are arranged close to each other and staggered is that a flat portion 4 other than the concave and convex portions 2 and 3 (for example, a strip portion 4a shown in the drawing).
Is to run on the panel 1 in a zigzag shape so that a linear flat portion is not formed. As a result, since a node (node) of a straight vibration cannot be formed, a panel structure in which the natural frequency of the panel is increased and the vibration is hardly obtained is obtained. In addition, when circular irregularities are formed, factors such as the size of the circle, the regularity of the irregularities, the interval between the irregularities, and the amount of the irregularities greatly affect the rigidity, that is, the vibration and soundproofing effect. For example,
By changing the size of the circular shape, vibration noise in various frequency bands can be suppressed in connection with the wavelength of the bending vibration of the panel, and by changing the depth of the unevenness, the size of the bending rigidity can be adjusted.
Therefore, these elements are usually individually set according to the object to which the panel is applied (vehicle or building, etc.) and the use site (ceiling or wall, etc.).

As described above, a circular concave or convex irregular shape is regularly formed in two in-plane directions of the plate.
The rigidity in the out-of-plane direction increases even with the same plate thickness. This utilizes the fact that the bending stiffness of a plate is proportional to the cube of the plate thickness, and it is desirable to make the interval between irregularities as small as possible so that a linear flat portion cannot be formed. Neutral line O by unevenness formation
The rigidity (see FIG. 2 (b)) is higher than that of a simple flat plate having no irregularities, and the natural frequency increases accordingly. The natural frequency increases as the depth (height) h of the unevenness increases. As an example, the thickness of the panel is a thin plate of about 1.2 mm, and the depth (h / 2) of the unevenness is about 2 mm.

The circular concave and convex portions 2 and 3 include substantially elliptical concave and convex portions close to a circle, but may have polygonal or rectangular concave and convex portions instead.

FIG. 3 (a) shows a cross section of the above-mentioned circular unevenness (this figure is shown here in FIG. 1 (b) for comparison with others).
Or the trapezoidal concave and convex portions 2a and 3a with respect to the neutral line O as shown in FIG. In the case of polygonal or rectangular irregularities, it is common to have the same trapezoidal irregularity sectional shape as in FIG.

Next, a second embodiment will be described with reference to FIGS. 4, 5 and 3 (c).

The panel 1A of the second embodiment is formed by bonding two perforated plates P1 and P2. That is, as shown in FIG. 4, a through hole 5 is provided in one plate P1 at the same position as the protrusion 3 shown in FIG. 1A of the first embodiment. As shown in FIG. 5, the other plate P2 has the plate P1 at the same position as the concave portion 2 shown in FIG. 1A of the first embodiment.
And a through-hole 6 having the same shape as the above.

When the two perforated plates P1 and P2 are overlapped and bonded with an adhesive, the shape is such that uneven portions 2b and 3b are formed at the same positions as in FIG. 1 (a). That is, (a) of FIG.
As is clear from the comparison between FIG. 1C and FIG. 1C, the through holes 5 and 6 of the two perforated plates P1 and P2 form a convex portion 3b corresponding to the convex portion 3 in FIG. Has become. This convex part 3
The portion other than b forms the concave portion 2b. In this example, the thickness of each of the perforated plates P1 and P2 is as thin as 0.8 mm.
When the sheets are stacked, the weight increases without the through holes 5 and 6. However, since a large number of through holes 5 and 6 serve as light holes, the result is almost the same as that of the first embodiment (a single panel having a thickness of 1.2 mm).

Although not shown, a structure in which a thin damping material is inserted and joined between the two perforated plates P1 and P2 is a panel having further added damping properties.

The panel having the above-mentioned uneven shape is as follows.
Since it has the same weight and high rigidity, it can be used not only as a panel with limited deformation but also as an interior panel for transportation equipment, or transmitted from the structure if it is used as an interior panel for transport equipment, or interior material due to noise generated outside the structure The vibration of the vehicle is reduced, and the noise in the vehicle and the room is also reduced. In addition, a structure in which two perforated plates are joined by shifting the holes, which is an extension of this concept, results in a lightweight and highly rigid interior material having a small weight corresponding to the holes.

The following experiment was conducted to examine the natural vibration characteristics of the flat plate having no unevenness and the circular uneven panel of the present invention (FIG. 1). As a test method, one corner of a square plate according to the circular uneven panel of the present invention (FIG. 1) is suspended so as to have four free ends, a weight is suspended at a corner opposed to the suspension point, and an acceleration sensor is provided near this corner. Provided. Then, the frequency response function was compared by striking above the center of the plate. FIG. 6 shows the results of the experiment. The vertical axis of FIG. 6 shows a transfer function dB as a response function of the vibration system, and the horizontal axis shows frequency Hz. Table 1 below shows the natural frequency and increase rate of each panel corresponding to the same vibration mode (the form of vibration at the time of resonance) from FIG.

[0027]

[Table 1]

From this table, it was confirmed that in the concavo-convex panel of the present invention, the main dominant frequency component shifted to a higher range as compared with the flat plate, and the natural frequency in each vibration mode increased significantly. Therefore, in the panel of the present invention, it is possible to obtain a vibration-proof and sound-proof effect while avoiding resonance with the vibration source.

[0029]

According to the invention of this application, since there are irregularities in two directions and irregularities in the out-of-plane directions on both sides, there is no anisotropy like a corrugated sheet, and the rigidity is the same with the same weight. You can get a panel. As a result, not only can the panel be used in general as a panel with limited deformation, but if it is used as an interior panel for transport equipment, the vibration of the interior panel due to noise transmitted from the structure or generated outside the structure will be reduced, and the interior of the vehicle will be reduced. Also, indoor noise can be reduced.

In particular, in a structure in which two perforated plates are joined by shifting the holes, a light-weight and high-rigidity interior panel having a small weight by the amount of the holes can be obtained. Further, a structure in which a vibration damping material is inserted between the two plates can be a panel having even greater vibration damping properties.

[Brief description of the drawings]

1A and 1B show a first embodiment, in which FIG. 1A is a plan view of a panel provided with circular irregularities, and FIG. 1B is a cross-sectional view taken along the line AA in FIG.

2 (a) is a partially enlarged plan view of FIG. 1 (a), and FIG. 2 (b) is a cross-sectional view taken along the line BB in FIG. 2 (a).

3 (a) is an enlarged sectional view of the circular unevenness of FIG. 1 (b), FIG. 3 (b) is a sectional view of the trapezoidal unevenness, and FIG. 3 (c) is a sectional view when the perforated plate is doubled. .

FIG. 4 is a plan view of a perforated plate constituting a high-rigidity panel according to a second embodiment.

FIG. 5 is a plan view of another perforated plate.

FIG. 6 is a diagram showing the results of a vibration test of a flat plate having no irregularities and the irregular panel of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Panel 2, 2a, 2b Concave part 3, 3a, 3b Convex part 4 Flat part 4a Strip part 1A Panel 5 Through-hole 6 Through-hole

Continuation of front page (72) Inventor Satoru Akiyama 2-1-1-18 Wadayama-dori, Hyogo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Hyogo Plant (56) References JP-A-63-214440 (JP, A) 63-166419 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) E04F 13/00-13/18 E04B 1/98 E04C 2/30 B62D 25/00 B62D 29/04 B32B 1/00-35/00

Claims (5)

(57) [Claims] 1. A single flat panel in two directions, lengthwise and widthwise.
In addition, irregularities are provided on both sides of this panel.
The flat part other than the unevenness is linear in any direction
Provided in a zigzag manner so as not to be formed
Lightweight rigid panels, characterized in that the. 2. The lightweight high-rigidity panel according to claim 1 , wherein the unevenness is any one of a circle, a polygon, and a rectangle. 3. The lightweight mold according to claim 1 , wherein an imaginary equilateral triangle having common vertices is drawn on the flat panel, and each of the vertices is provided with a concave or a convex, and the irregularities are arranged in a staggered manner. Rigid panel. 4. A two-hole plate with a large number of holes formed in a staggered manner, with the positions of the holes shifted and superimposed and bonded to form a single plate.
Nell and none, to form unevenness in the hole and the other part on both sides of the panel, moreover, the flat portions other than the uneven
So that it is not formed linearly in any direction.
A lightweight, high-rigidity panel characterized by providing unevenness close to each other . 5. The lightweight high-rigidity panel according to claim 4 , wherein a damping material is sandwiched between two perforated plates.