JP2003165466A - Vehicle floor panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain high simplicity, cost and weight reductions, high sound proofing performance, and high vehicle body stiffness. <P>SOLUTION: The bottom 4 of a floor panel 1 is partitioned, and each of the partitioned bottom sections is provided on a floor panel body 6 formed into a pan-bottom shape so that a floor mat body 7 may come into close contact with it. The floor mat body 7 is structured by layering a sound insulating layer 9 and a skin 10 on a sound absorbing layer 8 brought into close contact with the floor panel body 6. Each of the bottom sections 4a is set so that resonance frequency of panel vibration produced may be higher than the resonance frequency of mat transmission loss which causes the sound shielding characteristic of the floor mat body 7 to degrade to the maximum. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floor panel of a vehicle which has improved soundproofing performance and is light in weight.

[0002]

2. Description of the Related Art Conventionally, in a soundproof structure for an automobile floor panel, in order to prevent external noise from entering the vehicle, an asphalt damping plate is provided on a steel plate, and felt and vinyl chloride sheet are laminated on it. The structure having the structure is generally used. Such a conventional floor panel soundproof structure is, for example, the structure shown in FIG. That is,
On the surface of the floor panel body 20, the floor panel body 2
A damping material 21, such as an asphalt-based material, is fused to attenuate the panel vibration of 0. And this damping material 21
The sound absorbing layer 22a made of felt or the like and the sound insulating layer 2
A floor mat main body 22 composed of 2b and a skin 22c is provided.

Sounds that enter the vehicle include a vibration transmission sound (mainly 500 Hz or less) and a transmitted sound (high frequency), and their characteristics are shown in FIG. 3, and the panel vibration (broken line of FIG. 3A). ) And the matte transmission loss (broken line in FIG. 3B). Normally, the panel vibration is dealt with by the damping material 21, and the transmitted sound is dealt with by adjusting the mass of the floor mat main body 22 and the damping material 21.

[0004]

Floor mat body 22
As shown in the matte transmission loss in FIG. 3 (b), the sound insulation characteristics due to [3] gradually become better on the high frequency side at the boundary of the resonance frequency fm1, but not so good on the low frequency side. Therefore, as shown in the panel vibration of FIG. 3A, the resonance frequency fp1 of the panel vibration that causes the highest vibration noise.
However, if it is set in the vicinity of the resonance frequency fm1 of the matte transmission loss or in a frequency range lower than this, there is a problem that sufficient soundproof performance cannot be obtained.

Further, since the damping material 21 fused to the floor panel body 20 has a heavy mass, various methods have conventionally been proposed to eliminate the damping material 21. For example, in JP-A-6-127436, the floor mat body 2
There is disclosed a technique in which the sound absorbing layer 22a of No. 2 is formed of a flexible polyurethane foam having a predetermined NCO index and air permeability to eliminate the damping material. However, in this prior art, there is a problem in that a complicated method or process is required to mold a desired flexible polyurethane foam, which is costly and cannot be handled as easily as a conventional felt is manufactured.

Further, in recent years, from the viewpoint of collision safety and the like, there is a growing demand for improving the rigidity of the vehicle body.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a floor panel of a vehicle, which can be easily and inexpensively reduced in weight, improved in soundproof performance, and improved in vehicle body rigidity. I am trying.

[0008]

In order to achieve the above object, a vehicle floor panel according to claim 1 of the present invention comprises a floor panel body and a floor mat body provided on the floor panel body. In the panel, a floor panel shape is formed so that a resonance frequency of panel vibration of the floor panel body is set higher than a resonance frequency of matte transmission loss of the floor mat body.

That is, the resonance frequency of the panel vibration of the floor panel body is set to be higher than the resonance frequency of the matte transmission loss of the floor mat body, so that the floor mat of the floor panel body can be used in a frequency range where the sound insulation performance of the floor mat body is excellent. The panel vibration is maximized, the soundproofing performance is greatly improved, the conventional damping material is not required, the weight of the vehicle body is reduced, and the cost is reduced. This can be easily done by changing the shape of the floor panel body, etc., and can contribute to the improvement of vehicle body rigidity.

A floor panel of a vehicle according to a second aspect of the present invention is the floor panel of a vehicle according to the first aspect. Specifically, the floor panel body is divided into a plurality of bottom portions. The feature is that the bottom is formed in the shape of a pan bottom.

Further, a vehicle floor panel according to a third aspect of the present invention is the vehicle floor panel according to the first aspect, specifically, the floor panel body has a bead-shaped portion protruding downward to a bottom portion. Is formed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 relate to an embodiment of the present invention, FIG. 1 is a perspective view illustrating a floor panel of a vehicle, FIG. 2 is a partial sectional view of a bottom portion of the floor panel, and FIG. 3 is panel vibration and matte transmission loss. 4 is a partial cross-sectional view of the bottom portion of the floor panel according to another example.

In FIG. 1, reference numeral 1 denotes a vehicle floor panel, and a tunnel portion 2 having an inverted U-shaped cross section is formed in the center of the floor panel 1 in the front-rear direction of the vehicle body. A floor frame 11 extending in the vehicle front-rear direction at left-right symmetrical positions of the floor panel 1 with the two being sandwiched therebetween.
However, side sills (not shown) are further formed on the left and right edge portions of the floor panel 1 outside the floor frame 11 to form a front and rear skeleton member. Further, a cross member 3 having an inverted U-shaped cross section and the like are formed from the tunnel portion 2 in the left-right vehicle width direction to form left and right skeleton members. The bottom portion 4 of the floor panel 1 is divided into a plurality of bottom portions 4a by the front and rear skeleton members and the left and right skeleton members.

FIG. 2 shows a partial sectional view of a part of the divided bottom portion 4a. Each bottom portion 4a of the floor panel 1 is provided with a floor mat body 7 that is substantially in close contact with a floor panel body 6 formed in a pan bottom shape.
Is formed by laminating a sound insulation layer 9 and a skin 10 on a sound absorption layer 8 made of felt, urethane mat, or the like that is in close contact with the floor panel body 6.

Therefore, since each bottom portion 4a is formed in the shape of a pan bottom, the rigidity is improved, and as shown by the solid line of the panel vibration of FIG. Resonance frequency fp1 of flat panel
It has a higher frequency fp2.

Further, since each bottom portion 4a is formed in a pan-bottom shape, the sound absorbing layer 8 of the floor mat body 7 can be formed deeply and thickly, and the resonance frequency fm2 of the matte transmission loss at which the sound insulation characteristic of the floor mat body 7 is most deteriorated. Can be moved to a lower frequency side than the conventional one, as shown by the solid line of the matte transmission loss in FIG.

By setting the resonance frequency fp2 of the panel vibration of the floor panel body 6 sufficiently higher than the resonance frequency fm2 of the matte transmission loss of the floor mat body 7, the resonance frequency fp2 at which the panel vibration becomes the highest is Since the mat body 7 can be set to a frequency range having excellent sound insulation characteristics, it is possible to eliminate the conventional damping material as shown in FIG.
As indicated by the solid line in (c), sufficient soundproof performance is obtained, and the weight and cost can be reduced.

Further, since the sound absorbing layer 8 of the floor mat body 7 according to the present embodiment can be formed by using a conventional felt or the like as it is, instead of a material formed by special treatment or conditions, it is cost-effective. It can be easily realized without increasing the cost.

The bottom portion 4 of the floor panel body 6 according to the present embodiment is configured such that each bottom portion 4a is formed in a pan bottom shape, but the bead shaped portion 15 protruding downward is formed in the bottom portion 4. By doing so, the above-mentioned effect can be obtained.

That is, as shown in FIG. 4, the bottom portion 4 of the floor panel 1 is provided with a bead-shaped portion 15 which projects downward in a predetermined direction (for example, the front-rear direction or the vehicle width direction) in a belt shape. In addition, a sound absorbing layer 8 made of felt, urethane mat, or the like, and a floor mat body 7 formed by laminating a sound insulating layer 9 and a skin 10 are provided in close contact with the bottom portion 4 on which the bead-shaped portion 15 is formed. There is.

Therefore, since the bead-shaped portion 15 is formed in the bottom portion 4, the rigidity is improved similarly to the above-described bottom portion 4a having the pot bottom shape, and as shown by the solid line of panel vibration in FIG. 3 (a), The resonance frequency of the generated panel vibration can be higher than the resonance frequency fp1 of the conventional flat panel, for example.

Further, since the bead-shaped portion 15 is formed on the bottom portion 4, the sound absorbing layer 8 of the floor mat main body 7 can be formed deeply and thickly at the bead-shaped portion 15 and the floor mat main body 7 can be formed. The resonance frequency of the matte transmission loss at which the sound insulation characteristic is most lowered can be moved to a lower frequency side than the conventional one, as shown by the solid line of the matte transmission loss in FIG.

Thus, by setting the resonance frequency of the panel vibration of the floor panel body 6 sufficiently higher than the resonance frequency of the matte transmission loss of the floor mat body 7, the resonance frequency at which the panel vibration becomes the highest can be set. Since it can be set to a frequency range with excellent sound insulation characteristics, sufficient soundproofing performance can be obtained, weight reduction and cost reduction can be achieved without the conventional damping material, as shown by the solid line in Fig. 3 (c). It has become.

Further, since the sound absorbing layer 8 of the floor mat body 7 according to the present embodiment can be formed by using the conventional felt or the like as it is, instead of a material formed by a special treatment or condition, it is cost-effective. It can be easily realized without increasing the cost.

The number of the bead-shaped portions 15 formed on the bottom portion 4 may be one or plural, and the bottom portion 4 forming the bead-shaped portions 15 is the bottom portion 4a divided as described above. May be

[0026]

As described above, according to the present invention, it is possible to obtain the effects that the weight can be reduced, the soundproof performance can be improved, and the vehicle body rigidity can be improved easily and at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a floor panel of a vehicle.

FIG. 2 is a partial sectional view of the bottom of the floor panel.

FIG. 3 is an explanatory diagram of sound due to panel vibration and matte transmission loss.

FIG. 4 is a partial sectional view of a bottom portion of a floor panel according to another example.

FIG. 5 is a partial sectional view of a bottom portion of a conventional floor panel.

[Explanation of symbols]

1 floor panel 4 bottom 4a bottom 6 Floor panel body 7 Floor mat body 15 Bead shape part

Claims (3)

[Claims] 1. A floor panel of a vehicle comprising a floor panel body and a floor mat body provided on the floor panel body, wherein the resonance frequency of panel vibration of the floor panel body is the resonance frequency of matte transmission loss of the floor mat body. A vehicle floor panel characterized by forming a floor panel shape to be set higher. 2. The floor panel for a vehicle according to claim 1, wherein the floor panel body has a plurality of bottom portions, and each of the divided bottom portions has a pan-bottom shape. 3. The floor panel of a vehicle according to claim 1, wherein the floor panel main body has a bead-shaped portion projecting downward at a bottom portion.