JP2002264742A - Bumper structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bumper structure of an automobile capable of exhibiting sound insulation and sound proof effect in a simple constitution. SOLUTION: A bumper cover 11 is disposed on the outside of a body panel 2. A gap space between the body panel 2 and the bumper cover 11 is constructed like a labyrinth, whereby entering sound from a noise sound source is transmitted along a transmission route formed by the gap space. A ventilator duct 4 is set as a region with a lower sound insulation at the innermost place of the transmission route. A lower end part 11a of the bumper cover 11 is extended, and typically formed to be bent substantially like a crank. The entering sound is transmitted while being reflected on the body panel 2 and the bumper cover 11, and in the course of repetitive reflection, the sound is gradually damped so that transmitted sound entering the cabin can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bumper structure for an automobile, and more particularly to a bumper structure provided with a bumper cover having a soundproof or soundproof structure against transmitted sound in a wagon or the like.

[0002]

2. Description of the Related Art Especially in a wagon vehicle or the like, a so-called transmitted sound is generated at, for example, a rear portion of the vehicle, and countermeasures against the transmitted sound have been conventionally taken. Here, the transmitted sound is a phenomenon in which a high-frequency sound (such as a tire sound) or an exhaust sound enters a vehicle interior from a part (such as a ventilator duct) where body sound insulation is low, while the vehicle is traveling particularly on a pavement road surface. This phenomenon is more likely to occur in a wagon vehicle without a partition panel than in a sedan vehicle.

FIG. 6 shows the area around a bumper of a wagon or the like of this type. In the following description, noise such as exhaust noise and tire noise generated around a rear bumper at the rear of the vehicle will be described. In FIG. 6, a rear bumper 1 is arranged behind the rear tire 100. 7 and 8 show a conventional rear bumper structure. FIG. 7 is a longitudinal sectional view thereof, and FIG. 8 is a plan sectional view thereof. In these figures, 2 is a body panel, and 3 is a bumper cover.

[0004] In the illustrated example, the exhaust noise generated when the vehicle is traveling on a pavement surface and the noise N generated from the tire 100 are shown.
However, the air enters the inside of the bumper cover 3 and penetrates, penetrates through the ventilator duct 4 and the like having low sound insulation, and enters the vehicle interior.

[0005] Therefore, as a conventional countermeasure against rear transmitted sound, a sound absorbing and insulating material is provided around the ventilator duct or on the entire back surface of the deck side trim, finish plate, or deck mat. Alternatively, a sealing material is provided at the end of these interior materials to prevent intrusion of exhaust noise and noise.

[0006]

However, conventional countermeasures against transmitted sound use a lot of soundproofing materials and the like, so that not only the cost is increased but also the weight is increased.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a vehicle bumper structure exhibiting excellent sound insulation and soundproofing effects with a simple structure.

[0008]

SUMMARY OF THE INVENTION A vehicle bumper structure according to the present invention is a vehicle bumper structure in which a bumper cover is arranged outside a body panel, wherein a gap space between the body panel and the bumper cover is formed as a maze. And the intrusion sound from the noise source is transmitted along the transmission path formed by the gap space.

Further, in the vehicle bumper structure of the present invention, it is preferable that a portion having low sound insulation is set at the back of the transmission path.

In the bumper structure for an automobile according to the present invention, it is more preferable that the lower end of the bumper cover is extended and bent to form the gap space in a maze shape.

Further, in the bumper structure for an automobile according to the present invention, the lower end of the bumper cover may be bent into a substantially crank shape.

Further, in the vehicle bumper structure of the present invention, the sound source includes a tire, and the low sound insulating portion includes a ventilator duct.

According to the present invention, the gap between the body panel and the bumper cover is formed in a maze by extending the lower end of the bumper cover and bending and forming the bumper cover, typically in a substantially crank shape. By forming the transmission path of the intrusion sound from the noise source in a maze like this, the intrusion sound is transmitted while being reflected on the body panel and the bumper cover. Then, as this reflection is repeated, the sound is gradually attenuated, and the transmitted sound entering the vehicle interior can be significantly reduced.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A preferred embodiment of a vehicle bumper structure according to the present invention will be described. FIG. 1 shows the area around a rear bumper at the rear of the vehicle in this embodiment. In FIG. 1, a rear bumper 1 is arranged behind the rear tire 100, and a region S (see FIG. 2) from a corner of the rear bumper 1 to the rear tire 100 side.
To the present invention).

FIG. 3 is a perspective view of a main part showing a rear bumper structure in this embodiment. A bumper cover 11 is arranged outside the body panel 2, and a gap space between the body panel 2 and the bumper cover 11 is formed in a maze shape, and a noise source (a rear tire 100, a muffler (not shown), etc.)
Is transmitted along a transmission path formed by the gap space.

FIG. 4 shows a specific example of the rear bumper structure of the present invention. In the figure, the gap space between the body panel 2 and the bumper cover 11 is formed in a maze shape by extending the lower end portion 11a of the bumper cover 11 and typically bending and forming the bumper cover 11 into a substantially crank shape.
A ventilator duct 4, which is a portion having low sound insulation, is set in the gap space, that is, in the back of the transmission path.

In the above case, the lower end 1 of the bumper cover 11
In the illustrated example, three (i.e., a plurality of) crank portions (bending portions) are set in 1a. The number of these bent portions is not limited to those described in the illustrated example,
It can be increased or decreased as necessary, and its structure can be similarly changed. In addition, the bumper cover 11 can be manufactured by the same manufacturing method as the current one. That is, in the manufacturing die, the die removing direction and the like may be the same, and the same manufacturing process can be maintained.

In the above configuration, the noise (part of) N from the rear tire 100 is transmitted along a transmission path as indicated by an arrow.
It enters the gap between the body panel 2 and the bumper cover 11. Here, since the lower end portion 11a of the bumper cover 11 is bent and formed in a substantially crank shape as described above, the intrusion sound is transmitted to the body panel 2 and the bumper cover 11 while being reflected. Then, as this reflection is repeated, the sound gradually attenuates, and the transmitted sound that penetrates through the ventilator duct 4 and enters the vehicle interior can be significantly reduced.

Further, some noise N 'generated from the rear tire 100 and the muffler is reduced by the bumper cover 1 as shown in FIG.
Since the light is reflected by the lower end portion 11a, the sound cannot enter the transmission path, so that a direct sound can be prevented. With such a simple configuration in which only the lower end portion 11a of the bumper cover 11 is formed, an excellent countermeasure against transmitted sound can be achieved.

FIG. 5 is a graph showing the result of measuring transmitted sound in an actual vehicle (specific A vehicle). In the graph of FIG. 5, the solid line shows the measurement result of the vehicle with the soundproof material, and the dotted line shows the measurement result of the bumper structure according to the present invention. According to the present invention, the high-frequency rear transmitted sound is reduced to about 0.7 dB.
It was confirmed that the transmitted sound could be reduced to a certain extent, and that it had an excellent transmitted sound reduction effect.

As described above, the preferred embodiment of the present invention has been described. However, it is possible to make appropriate changes within the scope of the present invention. For example, an example has been described in which the gap space between the body panel 2 and the bumper cover 11 is configured in a maze shape by bending the lower end portion 11a of the bumper cover 11 into a substantially crank shape. It may include a curved shape or the like. In the above-described embodiment, the rear bumper has been described. However, the present invention is not limited to this, and it is needless to say that the present invention can be similarly applied to a body panel, a front bumper, and a body side bumper.

[0022]

As described above, according to the present invention, by effectively utilizing the bumper cover in this type of bumper structure, it is possible to effectively prevent transmitted sound without additional parts, thereby providing a soundproofing material. Reduces the cost and weight. In addition to being easy to manufacture, in addition to measures against transmitted sound, it has advantages such as exhibiting excellent effect performance in measures against splash noise, dust and snow invasion, and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a periphery of a rear bumper at a rear portion of a vehicle according to an embodiment of the present invention.

FIG. 2 is a plan cross-sectional view illustrating a periphery of a rear bumper at a rear portion of the vehicle in the embodiment.

FIG. 3 is a main part perspective view showing a rear bumper structure in the embodiment of the present invention.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. 1 showing a specific structure example of a rear bumper structure in the embodiment of the present invention.

FIG. 5 is a graph showing measurement results of transmitted sound in the embodiment of the present invention.

FIG. 6 is a perspective view showing a structure around a conventional rear bumper.

FIG. 7 is a longitudinal sectional view of a conventional rear bumper structure.

FIG. 8 is a plan sectional view of a conventional rear bumper structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rear bumper 2 Body panel 4 Ventilator duct 11 Bumper cover 11a Lower end 100 Rear tire

Claims (5)

[Claims] 1. A bumper structure for an automobile in which a bumper cover is arranged outside a body panel, wherein a gap space between the body panel and the bumper cover is formed in a maze shape, and an intrusion sound from a noise source is reduced. And a transmission along a transmission path formed by the gap space. 2. The bumper structure for an automobile according to claim 1, wherein a portion having low sound insulation is set in a deep part of the transmission path. 3. The bumper structure for an automobile according to claim 1, wherein the gap space is formed in a maze shape by extending and lowering a lower end portion of the bumper cover. 4. The bumper structure for an automobile according to claim 3, wherein a lower end of the bumper cover is bent into a substantially crank shape. 5. The vehicle bumper structure according to claim 1, wherein the sound source includes a tire, and the low sound insulation portion includes a ventilator duct.