JP2006298126A - Floor undercover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a floor undercover capable of suppressing the transmission of noise between a lower surface of a vehicular floor and a road surface to a vehicular room. <P>SOLUTION: The floor undercover 1 is provided with a case dividing at least a part of a resonant space 3, and a communicating hole 4 formed to penetrate the case and communicating the resonant space 3 and the outside. The floor undercover 1 is disposed on a lower surface 20 of a floor 2 of a vehicle V. In the lower surface of the case, a surface 11 having an elevation angle on a front side to the road surface and a surface 12 having an elevation angle on a rear side to the road surface are disposed in a traveling direction of the vehicle, and the communicating hole 4 is opened on the surface 12 having the elevation angle on the rear side to the road surface. The floor undercover silences noise between the lower surface of the vehicular floor and the road surface, so that noise felt in the vehicular room can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a floor under cover that is attached to a lower surface of a vehicle floor that faces a road surface, and more particularly to a floor under cover that absorbs noise between the lower surface of the floor and the road surface to prevent transmission of noise to the vehicle interior. Regarding the cover.

  Vehicles emit various noises during travel. One source of noise generated by vehicles is the engine. Noise generated by the engine is absorbed by placing a sound absorbing material on the inner wall of the engine room. For example, Patent Document 1 discloses disposing a sound absorbing material on an engine undercover and an engine cover.

  There is also a method of canceling the sound by interfering with a sound having a frequency shifted in phase with respect to the noise. In Patent Document 2, a through-hole having a space around is formed in the engine undercover.

  However, the noise generated by the vehicle includes not only noise generated by the engine but also road noise generated between the tire and the road surface during traveling. The undercover described in each of the above patent documents is intended to remove noise generated by the engine, and it is difficult to remove road noise.

In particular, road noise resonates between the lower surface of the floor of the vehicle and the road surface, and is transmitted as a booming sound to the passenger compartment. In other words, passengers in the passenger compartment felt noise.
JP 2004-175200 A JP 2004-170584 A

  This invention is made | formed in view of the said actual condition, and makes it a subject to suppress that the noise between the lower surface of the floor of a vehicle and a road surface is transmitted to a vehicle interior.

  In order to solve the above problems, the present inventor has made studies of the present invention as a result of repeated studies on removing noise between the lower surface of the vehicle floor and the road surface.

  That is, the floor under cover of the present invention has a case that partitions at least a part of the resonance space, and a communication hole that is formed through the case and communicates the resonance space with the outside, and is disposed on the lower surface of the vehicle floor. The bottom surface of the case is such that the lower surface of the case has a surface with an elevation angle on the front side with respect to the road surface and a surface with an elevation angle on the rear side with respect to the road surface along the traveling direction of the vehicle The communication hole is opened on a surface having an elevation angle on the rear side with respect to the road surface.

  The floor under cover of the present invention provides a resonance space between the lower surface of the floor of the passenger compartment and the road surface. Thereby, the noise between the lower surface of the floor of the vehicle and the road surface is silenced. Noise does not resonate between the lower surface of the vehicle floor and the road surface, and noise generated when the vehicle travels can be reduced. In addition, since noise does not resonate between the lower surface of the vehicle floor and the road surface, it is possible to reduce noise felt in the passenger compartment.

  The floor under cover of the present invention has a case that defines a resonance space and a communication hole that is formed through the case and communicates the resonance space with the outside. In the floor undercover of the present invention, noise enters the resonance space from the communication hole. And it reflects on the wall surface which divides resonance space, the phase of a sound wave shifts | deviates, and the sound wave from which the phase shifted | deviated is radiated | emitted outside from a communicating hole. At this time, the sound radiated from the communication hole and the noise near the opening of the communication hole interfere with each other to attenuate the noise. As a result, the floor underbar of the present invention silences noise between the lower surface of the vehicle floor and the road surface. The floor undercover according to the present invention muffles noise between the lower surface of the vehicle floor and the road surface, and can open a communication hole at least on the lower surface of the case facing the road surface.

  In the floor under cover of the present invention, the lower surface of the case that defines the resonance space has a surface having an elevation angle on the front side with respect to the road surface, and a surface having an elevation angle on the rear side with respect to the road surface. The shape is arranged along the direction of travel. And the communicating hole has opened on the surface which had the elevation angle in the back side with respect to the road surface. In this way, the lower surface of the case is formed in at least an uneven shape, and the communication hole opens on the surface having an elevation angle on the rear side with respect to the road surface, thereby preventing air flow between the lower surface of the vehicle floor and the road surface. Noise can be silenced without any problems.

  The surface having the elevation angle on the front side with respect to the road surface and the surface having the elevation angle on the rear side with respect to the road surface may be any surface as long as the surface has an elevation angle with respect to the road surface. It does not have to be formed.

  The angle formed by the surface having an elevation angle on the front side with respect to the road surface with respect to the road surface is preferably smaller than the angle formed by the surface with the elevation angle on the rear side with respect to the road surface with respect to the road surface. By reducing the angle formed by the surface having an elevation angle on the front side with respect to the road surface with respect to the road surface, the flow of air flowing between the lower surface of the floor of the vehicle and the road surface is not hindered. That is, resistance during running does not increase because air smoothly flows between the lower surface of the floor of the vehicle and the road surface. Further, since the angle formed by the surface having an elevation angle on the rear side with respect to the road surface with respect to the road surface is increased, water on the road surface is less likely to enter the internal resonance space from the communication hole opened on the surface.

  And since a communicating hole opens in the surface which has an elevation angle on the back side with respect to the road surface, the air flow on the lower surface of the floor of the vehicle is not hindered. When the communication hole opens in a plane extending along the road surface, wind noise is generated by the air flow and the opening of the communication hole. Further, when the communication hole is opened on the surface having an elevation angle on the front side with respect to the road surface, not only noise but also water splashed up easily flows into the communication hole. Thus, the silencing effect is obtained without blocking the air flow by opening the communication hole on the surface having an elevation angle on the rear side with respect to the road surface.

  The communication hole is preferably opened at the lower end of the surface having an elevation angle on the rear side with respect to the road surface. The end on the lower side indicates the lowest position in the vertical direction of the surface having an elevation angle on the rear side with respect to the road surface. Since the communication hole opens at the lower end of the surface, it is difficult for water to enter from the communication hole, and water (puddle water, etc.) on the road surface enters the resonance space from the communication hole. However, the resonance space of the communication hole flows down the resonance space along the inner surface that divides the resonance space (the surface facing the road surface on the front side of the case or the back surface of the surface facing the road surface on the rear side). It flows into the opening on the side and flows down to the outside. That is, water does not accumulate in the resonance space. Also, no wind noise is generated.

  The inner surface that defines the resonance space of the case is preferably formed to be inclined toward the communication hole. Since the inner surface is formed to be inclined toward the communication hole, moisture or the like that has flowed into the resonance space easily flows down to the outside.

  The floor under cover of the present invention defines a resonance space on the lower surface of the vehicle floor. This resonance space may be defined by only the case, or may be defined by the case and the lower surface of the vehicle floor. By partitioning the case and the lower surface of the vehicle floor, it is not necessary to partition the hollow resonance space, so that the floor undercover can be easily manufactured. That is, the manufacturing cost can be greatly reduced. That is, in the floor undercover of the present invention, it is preferable that the lower surface of the vehicle floor defines a part of the resonance space.

  It is preferable that a sound absorbing material having sound absorbing properties is disposed. The sound that is muted by the resonance space is a sound having a specific waveform (wavelength). For this reason, depending on the setting of the resonance space, other waveforms cannot be silenced. The sound absorbing material absorbs sound in a wide frequency range. In other words, by having the sound absorbing material, a higher silencing effect can be obtained. The position where the sound absorbing material is arranged is not particularly limited. For example, it is preferable to provide on the upper surface that defines the upper part of the resonance space.

  In the floor undercover of the present invention, the number of resonance spaces for silencing noise is not limited. That is, either a single resonance space or a plurality of resonance spaces may be used. When a plurality of resonance spaces are provided, it is preferable that a communication hole is provided in each resonance space. At this time, a plurality of communication holes are not formed in one resonance space.

  When having a plurality of resonance spaces, even if the resonance spaces are aligned in the vehicle width direction, aligned in the vehicle front-rear direction, aligned in the vehicle vertical direction, Any of these states may be used in combination.

  In the case of having a plurality of resonance spaces, it is preferable that all the communication holes communicating with the respective resonance spaces are opened on the surface facing the lower surface on the rear side. It is preferable that a surface facing the road surface on the front side and a surface facing the road surface on the rear side are continuously provided alternately in the front-rear direction of the vehicle.

  The material for forming the floor under cover of the present invention is not particularly limited, and materials such as metal and resin can be used.

  Hereinafter, the present invention will be described using examples.

Example 1
The floor under cover of the present embodiment is a cover 1 that is attached to the lower surface 20 facing the road surface of the floor 2 of the vehicle V as shown in FIGS. FIG. 1 is a view showing a side surface of a vehicle V to which a cover 1 of this embodiment is attached so that the arrangement of the cover 1 can be understood. FIG. 2 is a cross-sectional view of the cover 1 of the present embodiment in the longitudinal direction of the vehicle.

The cover 1 of the present embodiment partitions the resonance space 3 with the lower surface 20 of the floor 2 of the vehicle V. In the resonance space 3, the side wall 10 extending in the vertical direction defines the circumferential direction. And, at the lower end of the side wall 10, two lower surface walls 11 and 12 arranged in the front-rear direction of the vehicle are integrally provided. Of the two lower surface walls 11 and 12, the lower surface wall 11 located on the front side of the vehicle has an elevation angle on the front side with respect to the road surface of the surface 110 facing the road surface. That is, the lower wall 11 is provided with an inclination so that the front side is positioned vertically above the lower side. The opposing surface 110 of the lower wall 11 corresponds to a surface having an elevation angle on the front side with respect to the road surface in the claims of the present invention. Further, the lower wall 12 is provided to be inclined in the opposite direction to the lower wall 11. In the present embodiment, the side wall 10 and the lower surface walls 11 and 12 constitute a case of the claims. That is, the resonance space 3 was partitioned by the side wall 10, the lower surface walls 11, 12 and the floor 2. Further, the side wall 10 and the lower surface walls 11, 12 that define the resonance space 3 have a substantially plate shape, and the shape of the resonance space 3 substantially matches the outer peripheral shape of the side wall 10 and the lower surface walls 11, 12. In the present embodiment, the elevation angle (θ ₁ ) formed by the lower surface wall 11 on the front side with respect to the road surface is formed smaller than the elevation angle (θ ₂ ) formed by the lower surface wall 12 on the front side with respect to the road surface.

  A communication hole 4 that communicates the outside with the resonance space 3 is opened at the lower end of the lower wall 12.

  Further, as shown in FIG. 2, the cover 1 of this embodiment has three resonance spaces 3, 3, 3 arranged side by side in the front-rear direction of the vehicle. At this time, the adjacent resonance spaces 3 and 3 share the side wall 10. That is, one side wall 10 defines two resonance spaces 3 and 3.

  The effect of the cover 1 of a present Example is demonstrated below.

  In the cover 1 of this embodiment, the communication hole 4 is open toward the road surface. Noise between the lower surface 20 of the floor 2 and the road surface enters the resonance space 3 from the communication hole 4. The phase of the incident sound wave is shifted by half a wavelength in the resonance space 3 by an action such as reflection. And it radiates | emits outside through the communicating hole 4. FIG. At this time, the sound incident on the communication hole 4 and the radiated sound are out of phase by a half wavelength, and the two sounds interfere with each other and mute. Thereby, the cover 1 of a present Example muffles the noise between the lower surface 20 of the floor 2, and a road surface.

  The wavelength of the sound that the cover of the embodiment silences can be appropriately determined according to the shape and volume of the resonance space 3 and the opening diameter of the communication hole 4. Further, the adjacent resonance spaces 3 may be formed so as to mute sounds having different wavelengths.

  In the cover of this embodiment, the lower surface wall 11 is formed to be inclined so that air flows in a direction along the lower surface wall 11. That is, it is difficult for air to flow along the surface 120 facing the road surface of the lower wall 12. As a result, the phenomenon of sucking out from the resonance space 3 through the communication hole 4 is less likely to occur. That is, the cover of the present embodiment can muffle noise by eliminating wind noise caused by the air flow between the lower surface 20 of the vehicle floor 2 and the road surface.

  Furthermore, even when water splashes due to running on a puddle on the road surface, the bottom wall 12 does not face the traveling direction of the vehicle, so that the water splashed on the bottom wall 12 is difficult to hit. As a result, it is difficult for water to enter the resonance space 3 from the communication hole 4. Even if water enters the resonance space 3, it flows down along the side wall 10 in the direction of the lower surface walls 11 and 12. The water flowing down in the resonance space 3 flows down along the lower wall 11 or the lower wall 12. Then, it flows down from the communication hole 4 opened at the lower end of the lower wall 12 to the outside. Thereby, water does not accumulate in the resonance space 3.

Further, since the elevation angle (θ ₁ ) is reduced, the flow of air flowing between the lower surface of the vehicle floor and the road surface is not hindered. That is, resistance during running does not increase because air smoothly flows between the lower surface of the floor of the vehicle and the road surface. By increasing the elevation angle (θ ₂ ), it becomes difficult for water or the like on the road surface to enter the internal resonance space 3 from the communication hole 4 opened in the lower wall 12.

  Furthermore, the cover of the present embodiment also exhibits an effect as an undercover. Specifically, even if a pebble or the like is flipped up during traveling, it does not hit the lower surface 20 of the floor 2 of the vehicle V. As a result, it is possible to prevent the pebbles from damaging the lower surface 20 when the lower surface 20 of the floor 2 is damaged (for example, damaging the anticorrosive coating). Further, since the pebbles do not fall on the floor 2, noise generated when the pebbles hit is not transmitted to the vehicle interior.

(Example 2)
The configuration of the floor undercover of this example is shown in FIG. The cover of the present embodiment has the same configuration as the cover of the first embodiment except that the sound absorbing material 5 is arranged on the lower surface 20 side of the floor 2 that defines the upper portion of the resonance space 3 in the side wall 10.

  The cover of the present embodiment exhibits the same effect as the cover of the first embodiment. Furthermore, the cover of the present embodiment has the sound absorbing material 5, so that it is possible to absorb noise that could not be silenced by the action of the resonance space 3.

(Example 3)
The configuration of the floor undercover of this example is shown in FIG. The cover of the present embodiment has the same configuration as that of the cover of the first embodiment except that the upper portion of the resonance space 3 is partitioned by an upper surface wall 13 formed integrally with the side wall.

  In the cover of this embodiment, the resonance space 3 is defined by the side wall 10, the lower surface walls 11, 12 and the upper surface wall 13. That is, noise that has entered the resonance space 3 is not directly applied to the lower surface 20 of the floor 2 of the vehicle V. Thereby, the effect which can further reduce the noise transmitted to a vehicle interior via the floor 2 is exhibited.

Example 4
The configuration of the floor undercover of this example is shown in FIG. The cover of this embodiment has the same configuration as that of the cover of Embodiment 1 except that the two resonance spaces 30 and 31 are stacked in the vertical direction.

  The cover 1 of the present embodiment has an intermediate wall 14 in addition to the side wall 10 and the lower surface walls 11 and 12 that define the resonance space 3 of the cover of the first embodiment. The intermediate wall 14 is connected to the side wall 100 and the lower surface wall 12 on the front side. Specifically, it extends in the horizontal direction from the side wall 100 toward the rear, and has a shape bent from the vicinity of the central portion in the front-rear direction of the resonance space 3.

  In the cover 1 of this embodiment, the resonance space 30 is defined by the side wall 10, the lower surface walls 11, 12 and the intermediate wall 14, and the resonance space 31 is defined by the side wall 10, the intermediate wall 14 and the lower surface 20 of the floor 2. In addition, communication holes 40 and 41 communicating the outside and the respective resonance spaces 30 and 31 are opened at the lower end portions of the portions defining the resonance spaces 30 and 31 of the lower wall 12.

  The cover of the present embodiment exhibits an effect of silencing noise in the same manner as the cover of the first embodiment except that the two resonance spaces 30 and 31 are arranged in the vertical direction. Moreover, the cover of a present Example can adjust the silencing characteristic of each resonance space 30 and 31 by adjusting the volume etc. of the two resonance spaces 30 and 31. FIG. That is, the effect that the sound of different frequencies can be silenced is exhibited. Furthermore, by having the intermediate wall 14, it becomes a double wall structure, and demonstrates a great effect by suppressing transmitted sound. In addition, you may comprise the cover of a present Example by combining a some cover division | segmentation.

It is a side view of the vehicle with which the floor under cover of Example 1 was attached. It is sectional drawing of the floor undercover of Example 1. FIG. It is sectional drawing of the floor undercover of Example 2. FIG. It is sectional drawing of the floor undercover of Example 3. It is sectional drawing of the floor undercover of Example 4.

Explanation of symbols

1: Floor under cover 10: Side wall 11, 12: Bottom wall 13: Top wall 14: Intermediate wall 2: Floor 3, 30, 31: Resonance space 4, 40, 41: Communication hole 5: Sound absorbing material

Claims (5)

A floor undercover disposed on a lower surface of a vehicle floor having a case that partitions at least a part of the resonance space, and a communication hole that is formed through the case and communicates with the resonance space and the outside;
The lower surface of the case has a surface having an elevation angle on the front side with respect to the road surface and a surface having an elevation angle on the rear side with respect to the road surface, arranged along the traveling direction of the vehicle,
A floor under cover, wherein the communication hole is opened on a surface having an elevation angle on the rear side with respect to the road surface.   2. The floor undercover according to claim 1, wherein the communication hole is opened at a lower end of a surface having an elevation angle on the rear side with respect to the road surface.   The floor undercover according to claim 1, wherein a lower surface of the floor of the vehicle defines a part of the resonance space.   The floor undercover according to claim 1, wherein a sound absorbing material having sound absorbing properties is disposed.   A surface having an elevation angle on the front side with respect to the road surface and a surface having an elevation angle on the rear side with respect to the road surface are arranged alternately and continuously in the traveling direction of the vehicle. The floor under cover according to 1.

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