JPH10278786A - Floor material for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have a light weight and reduce the noise under a floor. SOLUTION: A plurality of aluminum extruded structural angles 1 which have the wall-thickness 1-5 mm and have the rectangular cross sections crossing at right angles with the extrusion direction are arranged in parallel to each other at 200-600 mm intervals. The aluminum extrusion structural angles 1 are sandwiched between two complex damping aluminum alloy sheets 4 which have the thickness 1-5 mm and are constituted of a damping aluminium alloy sheet 2 and a damping resin 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle flooring used for railway vehicles, and more particularly to a vehicle flooring that is lightweight and can reduce noise.

[0002]

2. Description of the Related Art Conventionally, lightweight and extremely high rigidity aluminum alloy bonded honeycomb floors have been widely used as indoor floors of high-speed railways. FIG. 6 is a schematic sectional view showing a conventional aluminum alloy bonded honeycomb floor. As shown in FIG. 6, the conventional aluminum alloy bonded honeycomb floor has two
A plurality of aluminum alloy face plates 9 arranged in parallel and a core portion 10 constituted by a plurality of aluminum alloy plates arranged in parallel are sandwiched between the aluminum alloy face plates 9. Since the honeycomb floor of this prior art is made of an aluminum alloy plate, it is possible to reduce the weight of a vehicle required for speeding up a railway. But,
The effect of reducing noise when using a honeycomb floor is small. For this reason, a steel floor having a high areal density and a large sound transmission loss is used in a region where the noise from the floor is large.

FIG. 7 is a schematic sectional view showing a conventional steel floor. As shown in FIG. 7, a conventional steel floor is formed by combining an L-shaped angle 12 made of a steel plate and a U-shaped angle 13 made of a steel plate to form a core of the floor material, and the core is sandwiched between the steel plates 11. It is configured. Since this conventional steel floor has a high surface density, it is possible to prevent noise generated from various devices installed under the floor from entering the room.
However, the heavy weight of the steel floor impedes the speeding up of the railway and causes a reduction in energy efficiency during traveling.

In order to reduce noise efficiently, a floor material for a vehicle has been proposed (Japanese Patent Laid-Open No. 1-269663). In this conventional technique, a filler is filled in the gap between the honeycomb cores. Thus, noise is reduced by removing the air layer having high sound propagation properties from the inside of the honeycomb core. However, a foamed resin material generally used as a filler is used, and the effect of reducing noise by filling the filler is not sufficient.

Further, a floor material of a vehicle having a honeycomb core having a multilayer structure has been proposed in order to reduce the reverberation sound generated when walking in the vehicle (Japanese Utility Model Laid-Open No. 23571/1992). In this prior art, a honeycomb panel is formed by laminating one or more layers of an aluminum honeycomb core and an aramid fiber honeycomb core impregnated with a phenol resin via a prepreg agent containing glass fibers. According to this conventional technique, since the aramid fiber honeycomb core impregnated with the phenol resin is provided, the rigidity is increased, so that the reverberation sound during walking in the vehicle can be reduced. However, the effect of reducing noise from various devices under the floor is small.

Further, there has been proposed a method of reducing noise by injecting a sound absorbing substance into a floorboard (Japanese Patent Laid-Open No. 6-2).
No. 19272). According to this conventional technique, a vertical partition is formed in a hollow floor plate, and a sound absorbing substance corresponding to the frequency of noise from a noise source under the floor is injected into the hollow. According to this conventional technique, noise from under the floor is absorbed by the sound absorbing substance corresponding to the frequency of the noise,
Noise is reduced.

[0007]

However, even the method of injecting the sound absorbing substance into the floorboard is not sufficient in preventing the increase in noise due to the recent increase in speed of railways.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a floor material of a vehicle which is lightweight and can reduce noise from under the floor.

[0009]

According to a first aspect of the present invention, there is provided a vehicle flooring material comprising two composite vibration-damping aluminum alloy plates which are arranged in parallel and have a plate thickness of 1 to 5 mm, and 200 to 60 sandwiched between the composite damping aluminum plates
A plurality of extruded aluminum alloy members having a thickness of 1 to 5 mm and arranged in parallel at an interval of 0 mm, and wherein the extruded aluminum alloy material and the composite vibration-damping aluminum alloy plate are joined. It is characterized by the following.

[0010] According to the first aspect of the present invention, since the composite damping aluminum alloy plate is used as the front plate and the back plate of the indoor floor of the vehicle, the vibration of the indoor floor itself is reduced, and the vibration is generated by the vibration of the indoor floor. Noise can be reduced. In addition, since a plurality of extruded aluminum alloy members are used as the core material of the floor, and they are sandwiched between the composite vibration-damping aluminum alloy plates to form a closed cross-sectional structure, they are lightweight and are required for the indoor floor of the vehicle. The required rigidity is also secured.

Incidentally, The bonding is preferably performed by bonding with an adhesive, mechanical bonding, or a combination thereof. When performing joining by welding, the surface accuracy of the face plate may be reduced. However, when performing joining using an adhesive, mechanical joining, or a combination thereof, the surface accuracy can be increased.

Further, the extruded shape is desirably hollow. When the extruded shape is hollow, it is possible to realize weight reduction while having rigidity required as a floor material.

In the present invention, one of the thicknesses of the composite vibration damping aluminum alloy plate is t ₁ (mm), the other is t ₂ (mm), and the width of the extruded member in the longitudinal direction is Is W (mm), the thickness of the extruded aluminum alloy material is t ₃ (mm), the number is n, and the distance between the outer surfaces of the two composite damping aluminum alloy plates is H (mm). Then, (W × H ³ − (W−2 × t ₃ × n) × (H−t ₁
−t ₂ ) ³ ) / 12 is 3 ×
It is desirable that 10 ⁵ to ^{6 × 10 5 (mm 4)} .
When the second moment of area in the floor width direction is defined in this manner, the balance between the vibration damping performance and the rigidity of the indoor floor is further improved.

A flooring material of another vehicle according to the second invention of the present application has a plurality of aluminum alloy hollow extruded members each having a width of 200 to 600 mm and having ribs in the width direction, which are joined to each other by the ribs. The vibration-damping aluminum alloy hollow shape member is characterized in that a resin having a vibration-damping property is attached to the inner surface of the hollow aluminum alloy hollow member.

According to the second aspect of the present invention, since the resin having the vibration damping property is adhered to the inside of the hollow aluminum alloy hollow material, the vibration of the indoor floor itself is reduced, and the vibration is generated by the vibration of the indoor floor. Noise can be reduced.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies conducted by the inventors of the present application to solve the above-mentioned problems, it has been found that noise is heard indoors as follows. For one thing, noise is generated from various devices installed under the indoor floor of the vehicle, and the noise generated from the various devices penetrates through the airtight floor and the indoor floor, enters the room, and the noise is heard inside the room. There are cases. Further, vibrations generated from various devices may propagate to the airtight floor and the indoor floor, and the indoor floor may vibrate to emit noise to the room.

With respect to noise generated from various devices and penetrating into the room through the airtight floor and the indoor floor, the sound transmission loss is increased by increasing the surface density of the airtight floor and the indoor floor to increase the sound transmission loss. The amount of approach can be reduced.

In addition, vibrations of various devices are propagated to the airtight floor and the indoor floor, and the noise radiated by the vibration of the indoor floor is imparted to the indoor floor, Can be reduced by controlling the acoustic radiation efficiency. The sound radiation efficiency is a ratio of vibration energy of the vibration surface to sound energy radiated from the vibration surface. A sound radiation efficiency of 1 means that all of the vibration energy is converted to sound energy.

In many cases, noise is actually generated because vibrations of various devices propagate to the airtight floor and the indoor floor, and the indoor floor vibrates. When a honeycomb floor is used as a floor material of a vehicle, the acoustic radiation efficiency is extremely high because the honeycomb floor is lightweight but has extremely high rigidity. For this reason, a loud noise is generated even by a slight vibration of various devices.

Further, as a countermeasure against noise generated from the indoor floor due to underfloor equipment of a high-speed railway vehicle, a steel floor having a high surface density is often used. However, even when a steel floor having a high surface density is used, noise generated from various devices can be reduced from penetrating the indoor floor and entering the room, but the sound radiation efficiency is not reduced. . As described above, the noise is not effectively reduced because the indoor floor is often caused by the noise. Rather, increasing the weight of the vehicle causes a reduction in energy efficiency during traveling.

Accordingly, the present invention uses a composite damping aluminum alloy plate or a damping aluminum alloy hollow profile as a floor material of a vehicle, thereby reducing the weight of the vehicle and reducing the acoustic radiation efficiency of the indoor floor. It has been found that noise can be effectively reduced.

Next, a first embodiment of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a schematic sectional view showing a floor structure using a composite vibration damping aluminum alloy plate according to an embodiment of the present invention. As shown in FIG. 1, a plurality of aluminum hollow profiles 1 having a rectangular cross section orthogonal to the extrusion direction are arranged in parallel. The thickness of the aluminum hollow profile 1 is 1 to 5 mm, and the interval between the two aluminum alloy hollow profiles 1 is 200 to 600 mm. Further, a composite vibration-damping aluminum alloy plate 4 having a thickness of 1 to 5 mm is formed from the vibration-damping aluminum alloy plate 2 and the vibration-damping resin 3, and the aluminum hollow profile 1 is sandwiched between the composite vibration-damping aluminum alloy plates 4. Form the floor of the vehicle.

In the first embodiment, an aluminum alloy plate 2 and a vibration damping resin
The use of the composite vibration-damping aluminum alloy plate 4 having a two-layer structure reduces the vibration of the indoor floor itself, and reduces the noise generated by the vibration of various devices under the floor propagating to the indoor floor. it can.

Also, a plurality of extruded aluminum alloy members 1 are used as the core material of the floor, which is sandwiched between the composite vibration-damping aluminum alloy plates 4 to form a closed cross-sectional structure. The required rigidity of the indoor floor is also ensured.

Further, since the composite vibration-damping aluminum alloy plate 4 is used as the face plate, the manufacturable floor area per sheet is widened and the work efficiency can be improved.

Further, the composite vibration damping aluminum alloy plate 4 and the aluminum alloy hollow profile 1 are joined by an adhesive, a mechanical joint or a combination of an adhesive and a mechanical joint, and are joined by welding. Therefore, the surface accuracy of the composite vibration damping aluminum alloy plate 4 as the face plate can be increased.

The structure of the composite damping aluminum alloy is not limited to the two-layer structure, but is a three-layer structure in which a single-layer aluminum alloy plate, a vibration-damping resin and another one-layer aluminum alloy plate are sequentially laminated. Of a multi-layer structure such as a composite vibration damping aluminum alloy plate of the above. In addition,
The number and cross-sectional shape of the extruded aluminum alloy material 1 are as follows:
It is determined according to the required strength, rigidity and assembly dimensions.

Next, the reason for limiting the numerical values when a damping aluminum alloy plate is used will be described.

Interval of extruded aluminum alloy: 200
If the interval between the aluminum alloy extruded profiles is less than 200 mm, the rigidity of the entire floor becomes unnecessarily high,
Damping performance is reduced and sound radiation efficiency is increased. On the other hand, when the interval between the extruded aluminum alloy members exceeds 600 mm, the rigidity required for the indoor floor cannot be obtained. Therefore, the interval between the extruded aluminum alloy sections is 200 to 6
00 mm.

The thickness of the composite damping aluminum alloy sheet: 1
It is impossible to produce a composite damping aluminum alloy having a thickness of 5 mm or less and less than 1 mm. On the other hand, if the thickness of the composite vibration-damping aluminum alloy sheet exceeds 5 mm, the rigidity of the entire floor becomes excessively high, so that the vibration-damping performance decreases and the sound radiation efficiency increases. Therefore, the thickness of the composite vibration damping aluminum alloy plate is set to 1 to 5 mm.

Second moment of area in the floor width direction: 3 × 10
^The thickness of one of the ^{5 to} 6 × 10 ⁵ composite vibration damping aluminum alloy sheets is t ₁ (m
m), the other plate thickness is t ₂ (mm), the width in the longitudinal direction of the extruded profile is W (mm) (mm), the thickness of the aluminum alloy extruded profile is t ₃ (mm), When the number is n and the distance between the outer surfaces of the two composite damping aluminum alloy plates is H (mm), (W × H ³ − (W−2)
If the moment of inertia of cross section in the floor width direction represented by × t ₃ × n) × (Ht ₁ −t ₂ ) ³ ) / 12 is less than 3 × 10 ⁵ , it is sufficient for the indoor floor. High rigidity cannot be obtained. On the other hand, when the second moment of area exceeds 6 × 10 ⁵ , the rigidity becomes excessively high, the vibration damping performance decreases, and the acoustic radiation efficiency increases. Therefore, it is desirable that the second moment of area in the floor width direction is 3 × 10 ^{5 to} 6 × 10 ⁵ .

Next, a second embodiment according to the present invention will be described. FIG. 2 is a schematic cross-sectional view showing a floor structure using a damped aluminum alloy hollow profile according to an embodiment of the present invention. As shown in FIG. 2, the vibration-damping aluminum alloy hollow profile 5 has a rib in a direction parallel to its extrusion direction, and two vibration-damping aluminum alloy hollow profiles 5 are 200
Aligned with a width of ~ 600 mm. Further, a vibration damping resin 6 is attached to the upper surface side of the hollow portion. The aligned joint portions 7 of the ribs are joined by welding, rivets, adhesives, or the like to form the floor of the vehicle.

In the second embodiment, since the vibration damping resin 6 is adhered to the inside of the aluminum alloy hollow profile 5, the vibration damping property of the indoor floor can be improved and the noise can be reduced.

Further, since the vibration-damping aluminum alloy hollow profile 5 is used, the degree of freedom of the sectional shape of the unit to be used can be increased.

The cross-sectional shape of the damping aluminum alloy hollow profile 5 is determined according to the required strength, rigidity, assembly dimensions, and the like.

In the production of a vibration-damping aluminum alloy hollow profile, it is desirable to apply a vibration-damping resin to the inside of the aluminum alloy hollow profile simultaneously with the aluminum extrusion step. In this way, the number of work steps at the installation site can be reduced.

Next, the reason for limiting the numerical values when the vibration-damping aluminum alloy hollow material is used will be described.

Width of damping aluminum alloy hollow profile: 20
If the width of the 0 to 600 mm vibration-damping aluminum alloy hollow profile is less than 200 mm, the number of joints increases, so that necessary surface accuracy cannot be obtained and the acoustic radiation efficiency increases. On the other hand, if the width exceeds 600 mm, the rigidity required for the indoor floor cannot be obtained. Therefore, the width of the damping aluminum alloy hollow profile is 200 to 600 mm.

[0039]

EXAMPLES Examples according to the present invention will be described below in comparison with comparative examples outside the scope of the claims.

First Example First, test beds of Examples 1 and 2 and Comparative Examples 11 and 12 shown in Table 1 were prepared.

[0041]

[Table 1]

FIGS. 3A to 3H are schematic views showing the structure of the test floor, wherein FIG. 3A is a top view of the first embodiment, FIG. 3B is a cross-sectional view along AA ′, and FIG. Is a top view of the second embodiment,
(D) is a cross-sectional view along BB ', (e) is Comparative Example 11
(F) is a cross-sectional view along CC ′, (g) is a top view of Comparative Example 12, and (h) is a cross-sectional view along DD ′. As shown in FIGS. 3A to 3H, the first embodiment
And 2 and Comparative Examples 11 and 12 have the same dimensions.

Next, the weight and static deflection of the obtained test bed were measured. FIG. 4 is a schematic perspective view showing the deflection measurement method. As shown in FIG. 4, static deflection was measured by supporting both ends in the longitudinal direction of the test floor, applying a load of 88 kgf to the center, and using a dial gauge 8 at this time. Table 2 shows the measurement results.

[0044]

[Table 2]

As shown in Table 2 above, the weight of the vibration-damping aluminum alloy hollow profile floor according to Example 1 was less than half the weight of the steel floor according to Comparative Example 11. The weight of the composite vibration-damping aluminum alloy plate floor according to Example 2 was about 2/3 of that of the steel floor. The static deflection of Examples 1 and 2 is almost the same as that of Comparative Example 11.

Next, a test of the vibration damping performance of the test floor was performed.
The result is shown in FIG. In FIG. 5, the horizontal axis represents 1/3 octave frequency (Hz), and the vertical axis represents radiated sound pressure level (db).
FIG. 2 is a graph showing the relationship between the two. FIG.
In Table 1, the radiation sound pressure level is converted with the radiation sound pressure level of the steel floor set to 0. In addition, ▲ indicates Example 1, and ■.
Indicates Example 2, ● indicates Comparative Example 11, and Δ indicates Comparative Example 12. As shown in FIG.
In Comparative Example 12, a composite vibration-damping aluminum alloy material or a vibration-damping aluminum alloy hollow profile was used.
The vibration damping property of about 10 db is improved as compared with the honeycomb floor according to (1). Further, the composite vibration damping aluminum alloy floor according to Example 2 has a noise suppression effect in a frequency band of 1000 Hz or less.

Second Embodiment Next, composite damping aluminum alloy floors of Examples 3 and 4 and Comparative Examples 13 to 15 shown in Table 2 were produced.

[0048]

[Table 3]

Next, Examples 3 and 4 and Comparative Example 13
For each of Nos. 1 to 15, the amount of deflection was measured, and the damping performance was evaluated. In addition, the deflection amount of the steel floor conventionally used is about 3 mm. Therefore, it is desirable that the deflection amount is 3 mm or less. Furthermore, a comprehensive evaluation was also performed. Table 4 shows the results. In addition, in the column of the vibration suppression performance in Table 4, ○ indicates that the vibration suppression performance is excellent, and x indicates that the vibration suppression performance is inferior. In the column of comprehensive evaluation, OK indicates that the product is suitable, and NG indicates that the product is not suitable.

[0050]

[Table 4]

As shown in Table 4 above, in Examples 3 and 4, the thickness of the composite vibration-damping aluminum alloy plate as the face plate and the interval between the extruded aluminum alloy members were within the ranges specified in the present invention. , Deflection amount and vibration damping performance were excellent.

On the other hand, in Comparative Example 13, since the interval between the extruded aluminum alloy members was less than the lower limit of the range of the present invention, the rigidity was increased more than necessary and the vibration damping performance was inferior. In Comparative Example 15, since the interval between the extruded aluminum alloy members exceeded the upper limit of the range of the present invention, the required amount of deflection was high and the required rigidity could not be obtained.

In Comparative Example 14, since the thickness of the composite damping aluminum alloy plate as the face plate exceeded the upper limit of the range of the present invention, the rigidity was increased more than necessary and the damping performance was inferior.

Third Example Next, vibration-damped aluminum alloy hollow material floors of Examples 5 and 6 and Comparative Example 16 shown in Table 5 were produced.

[0055]

[Table 5]

Next, Examples 5 and 6 and Comparative Example 16
For each sample, the amount of deflection and the damping performance were evaluated in the same manner as in the second example. Further, the surface accuracy was also evaluated. And
Comprehensive evaluation. Table 6 shows the results. In the column of the surface accuracy in Table 6, ○ indicates that the surface accuracy is good, and X indicates that the surface accuracy is poor.

[0057]

[Table 6]

As shown in Table 6 above, in Examples 5 and 6, since the width of the hollow aluminum alloy material having damping properties was within the range specified in the present invention, the damping performance and surface accuracy were excellent. .

On the other hand, in Comparative Example 16, the width of the damped aluminum alloy hollow profile was less than the lower limit of the range of the present invention.
The number of joints increased and the surface accuracy decreased. For this reason,
Not suitable for products.

Fourth Example Next, composite damping aluminum alloy floors of Examples 7 to 10 and Comparative Example 17 shown in Table 7 were produced.

[0061]

[Table 7]

Next, Examples 7 to 10 and Comparative Example 17
Was evaluated for vibration damping and deflection. Table 8 shows the results. In addition, in the columns of vibration damping property and deflection in Table 8, OK indicates that it is extremely suitable for the product, and N
G indicates that it is not very suitable for the product.

[0063]

[Table 8]

As shown in Table 8 above, Examples 7 to 10
In the above, the second moment of area was within the range specified in the present invention, so that the vibration damping property and the deflection were good.

On the other hand, in Comparative Example 17, the plate thickness of the surface exceeded the upper limit of the range of the present invention, and the second moment of area also exceeded the upper limit of the range of the present invention. The properties were poor. For this reason, the radiated sound increased.

In Comparative Example 18, since the second moment of area exceeds the upper limit of the range of the present invention, the acoustic radiation efficiency is increased and is not suitable for products. On the other hand, Comparative Example 19
Since the second moment of area is less than the lower limit of the range of the present invention, it does not have sufficient rigidity and is not suitable for products.

[0067]

As described above, according to the present invention,
An aluminum alloy extruded profile having an appropriate thickness is sandwiched at an appropriate interval between composite vibration damping aluminum alloy plates having an appropriate thickness, and a composite vibration damping aluminum alloy plate and an aluminum alloy extruded Are joined by an adhesive, a mechanical joint, or a combination of an adhesive and a mechanical joint. Therefore, it is possible to obtain a vehicle floor material that is lightweight and can reduce noise from under the floor.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a floor structure using a composite damping aluminum alloy plate according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a floor structure using a damped aluminum alloy hollow profile according to an embodiment of the present invention.

3A and 3B are schematic diagrams showing a floor structure of a test floor, wherein FIG. 3A is a top view of Example 1, FIG. 3B is a cross-sectional view taken along AA ′,
(C) is a top view of Example 2, (d) is a cross-sectional view taken along BB ', (e) is a top view of Comparative Example 11, and (f) is C-
C is a cross-sectional view, (g) is a top view of Comparative Example 12,
(H) is sectional drawing in DD '.

FIG. 4 is a schematic perspective view showing a deflection measurement method.

FIG. 5 is a graph showing a relationship between a radiated sound pressure level and a 1/3 octave frequency.

FIG. 6 is a schematic sectional view showing a conventional aluminum alloy bonded honeycomb floor.

FIG. 7 is a schematic sectional view showing a conventional steel floor.

[Explanation of symbols]

 Reference Signs List 1: extruded aluminum alloy material 2: damping aluminum alloy 3, 6; damping resin 4: composite damping aluminum alloy plate 5; damping aluminum alloy hollow shape member 7; joint 8; 10; core part 11; steel plate 12; L-shaped angle 13;

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akio Sugimoto 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Inside Kobe Research Institute, Kobe Steel Ltd. (72) Inventor Shinichiro Takahashi Takatsuka, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel Co., Ltd.Kobe Research Institute, Kobe Steel Co., Ltd. (72) Inventor Kenji Iwai 1-8-2 Marunouchi, Chiyoda-ku, Tokyo Kobe Steel Co., Ltd. Tokyo Head Office (72) Inventor Onishi Hiroyuki Kobe City, Hyogo Pref.

Claims (5)

[Claims] 1. A composite vibration-damping aluminum alloy plate having a thickness of 1 to 5 mm and arranged in parallel and having a damping property, and a distance of 200 to 600 mm interposed between the composite vibration-damping aluminum plates. Are arranged in parallel and have a thickness of 1 to 5 m
m having a plurality of extruded aluminum alloy members,
A floor material for a vehicle, wherein the extruded aluminum alloy material and the composite vibration damping aluminum alloy plate are joined. 2. The flooring material for a vehicle according to claim 1, wherein the joining is performed by joining with an adhesive, mechanical joining, or a combination thereof. 3. The vehicle flooring according to claim 1, wherein the extruded profile is hollow. 4. A thickness of one of the composite vibration damping aluminum alloy is t ₁ (mm), a thickness of the other is t ₂ (mm), and a width dimension of the extruded material in a longitudinal direction is W (mm). The thickness of the extruded aluminum alloy material is t ₃ (mm), and the number is n.
When the distance between the outer surfaces of the two composite damping aluminum alloy plates is H (mm), (W × H ³ − (W−
2 × t ₃ × n) × (Ht ₁ −t ₂ ) ³ ) / 12, the secondary moment of area of 3 × 10 ^{5 to} 6 × 10 ⁵ (m
m ⁴ ), the vehicle flooring according to any one of claims 1 to 3. 5. A structure in which a plurality of aluminum alloy hollow extruded members each having a width of 200 to 600 mm and having ribs on both sides in the width direction are connected to each other by joining adjacent ones with the ribs. A floor material for a vehicle, wherein a resin having vibration damping properties is adhered to an inner surface of a vibration-absorbing aluminum alloy hollow profile.