Front grille structure

Abstract

In the conventional front grille structure, there is a possibility that Helmholtz resonance occurs due to an air flow passing through the gap during traveling.SOLUTION: A structure of a front grille 1 including a shield outer side 1A serving as a design surface and a shield inner side 1B disposed on a back surface side of the shield outer side 1A includes a gap 5 communicating in a vehicular front-rear direction between a peripheral edge of the front grille 1 and a vehicular main body M, and in the peripheral edge of the front grille 1, an end portion Eb of the shield inner side 1B is displaced to a grille center side with respect to an end portion Ea of the shield outer side wall, thereby suppressing generation of Helmholtz resonance due to an air flow S passing through the gap 5 and suppressing generation of abnormal noise during traveling.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a front grill structure used on the front of an automobile. [Background technology]

[0002] A conventional front grill structure is described, for example, in Patent Document 1. Patent Document 1 describes a front grill including a panel material having a design surface and a frame material provided adjacent to the rear side of the panel material. This front grill houses various devices constituting a radar device and the like between the panel material and the frame. Such front grilles are used, for example, in electric vehicles, which generate less heat than vehicles with internal combustion engines, and are not intended to introduce oncoming wind. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-59268 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-described front grille does not allow oncoming wind to pass through, thereby reducing air resistance. However, there is a gap between the grille and the vehicle body, such as the bumper or hood, through which the oncoming wind flows. In this case, the speed of the air flowing through the gap increases because the front grille does not allow oncoming wind to pass through from the front. For this reason, conventional front grille structures have a problem in that the air flowing through the gap during driving may resonate with the air in the equipment housing, resulting in the generation of abnormal noise due to so-called Helmholtz resonance.

[0005] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to provide a front grill structure that is composed of a shield outer and a shield inner and has a gap between it and the vehicle body, and that can suppress the occurrence of Helmholtz resonance caused by air flow passing through the gap while the vehicle is moving, thereby suppressing the occurrence of abnormal noise. [Means for solving the problem]

[0006] The front grill structure according to the present invention is a front grill structure including a shield outer that forms a design surface and a shield inner that is disposed on the rear side of the shield outer, and has a gap that communicates in the fore-and-aft direction of the vehicle between the periphery of the front grill and the vehicle body. The front grill structure is characterized in that, at the periphery of the front grill, the end of the shield inner is offset toward the center of the grill relative to the end of the shield outer. [Effects of the Invention]

[0007] In the front grill structure of the present invention, when the vehicle is moving, vortices are generated at the end of the shield outer due to the airflow passing through the gap between the front grill and the vehicle body. However, because the end of the shield inner is offset toward the center of the grille more than the end of the shield outer, the vortices pass toward the rear of the vehicle while diffusing without interfering with the end of the shield inner, thereby suppressing air resonance between the shield outer and shield inner.

[0008] In this way, the front grill structure of the present invention is a front grill structure that is composed of a shield outer and a shield inner and has a gap between it and the vehicle body, and can suppress the occurrence of Helmholtz resonance due to air flow passing through the gap while the vehicle is in motion, thereby suppressing the occurrence of abnormal noise. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing a first embodiment of a front grill structure. [Figure 2] FIG. 2 is an exploded perspective view of the front grille. [Figure 3] FIG. 2 is a cross-sectional view showing a main part of the front grill structure. [Figure 4] FIG. 4 is a cross-sectional view of a main part showing a second embodiment of the front grill structure. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment 1 and 2 is a front grill structure 1 including a shield outer 1A that serves as a design surface and a shield outer 1B that is disposed on the rear side of the shield outer 1A. The shield outer 1A in the illustrated example has a design surface 2 that serves as the front of the vehicle, and has a mounting portion 4 for an emblem 3 at the center of the upper part of the design surface 2. On the other hand, the shield inner 1B has a frame structure for mounting various devices that constitute, for example, a radar device.

[0011] The front grille 1 described above forms an equipment storage space 1C between the shield outer 1A and the shield inner 1B, and as shown in FIG. 1, there is a gap 5 between the periphery of the space 1C and the vehicle body M, which communicates in the longitudinal direction of the vehicle. The front grille 1 is fixed to the vehicle body M at predetermined locations. Therefore, the gap 5 is not continuous around the entire periphery of the front grille 1, but exists partially around the periphery of the front grille 1. The vehicle body M in the illustrated example is an integrated structure that includes functional parts such as a bumper B and lamps L, or locations where these are arranged.

[0012] 3, the front grill structure is configured such that the end of the shield inner 1B is offset toward the center of the grill (lower in FIG. 3) from the end of the shield outer 1A at the periphery of the front grill 1. Note that FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1.

[0013] 3, the shield outer 1A has a flange portion Fa at its end that extends toward the rear of the vehicle (to the right in FIG. 3). On the other hand, the shield inner 1B has a flange portion Fb that also extends toward the rear of the vehicle, located closer to the center of the grill (lower side) than the flange portion Fa of the shield outer 1A, and a protrusion P that protrudes from the tip of the flange portion Fb toward the gap 5 (upper side).

[0014] In addition, the vehicle body M has a flange portion Fm extending toward the rear of the vehicle at the end on the front grill 1 side, and a gap 4 communicating in the fore-and-aft direction of the vehicle is formed between this flange portion Fm and the flange portion Fa of the shield outer 1An.

[0015] Furthermore, as described above, the front grille 1 has a storage space 1C between the shield outer 1A and the shield inner 1B, and has an opening H that communicates with the storage space 1C between the end of the shield outer 1A and the end of the shield inner 1B. Like the gap 5, this opening H is not continuous around the entire periphery of the front grille 1, but exists partially around the periphery of the front grille 1, due to the need to connect the shield outer 1A and the shield inner 1B at predetermined locations.

[0016] In this way, the front grille 1 is configured such that the end Ea of the shield outer 1A, i.e., in the figure, the tip Ea of the flange portion Fa, is shifted toward the center of the grille, and the end Eb of the shield inner 1B, i.e., the upper end Eb of the protrusion P in the figure, is shifted to form a stepped surface, and the opening H is spaced away from the gap 5 toward the center of the grille.

[0017] In the front grill structure having the above configuration, when the vehicle is traveling, air flows into the gap 5 between the front grill 1 and the vehicle body M, and a vortex is generated at the end Ea of the shield outer 1A by the air flow S shown in Fig. 3. At that time, because the front grill structure displaces the end Eb of the shield inner 1B closer to the center of the grill than the end Ea of the shield outer 1A, the vortex does not interfere with the end Eb of the shield inner 1B and passes toward the rear of the vehicle while diffusing.

[0018] This allows the front grill structure to avoid resonance of the air between the shield outer 1A and the shield inner 1B, i.e., the air in the accommodation space 1C. Here, for example, in Fig. 3, if the end Eb of the shield inner 1B is located on an extension La from the end Ea of the shield outer 1A toward the rear of the vehicle, the opening H is also located on the same extension La. In this case, a vortex flow generated at the end of the shield outer 1A interferes with the end of the shield inner 1B, causing Helmholtz resonance, in which the air in the accommodation space 1C resonates through the opening H.

[0019] In contrast, the front grill structure of this embodiment suppresses the occurrence of the Helmholtz resonance by displacing the end Eb of the shield inner 1B relative to the end Ea of the shield outer 1A.

[0020] In this way, the above-mentioned front grill structure, in the structure of the front grill 1 which is composed of a shield outer 1A and a shield inner 1B and has a gap 5 between it and the vehicle body M, can suppress the occurrence of Helmholtz resonance due to the air flow S passing through the gap 5 while the vehicle is moving, thereby suppressing the occurrence of abnormal noise.

[0021] In addition, the above-mentioned front grill structure can more reliably prevent the occurrence of Helmholtz resonance due to the air flow S passing through the gap 5 by separating the opening H that communicates with the storage space 1C from the gap 5 toward the center of the grill.

[0022] In the above-mentioned front grill structure, the amount of deviation of the end Eb of the shield inner 1B relative to the end Ea of the shield outer 1A can be calculated based on the expected speed of the air flow S, the end shapes of the shield outer 1A and the shield inner 1B, the cross-sectional area of ​​the gap 5, etc.

[0023] Second Embodiment 4 has the same basic configuration as the first embodiment, and the shield inner 1B has only a flange Fb at its end, no protrusion (P in FIG. 3), and an opening H communicating with the accommodation space 1C opens toward the rear of the vehicle. As a result, the end Eb of the shield inner 1B is positioned closer to the center of the grill (lower in FIG. 4) than the end Ea of the shield outer 1A.

[0024] As with the first embodiment, the above-described front grill structure can suppress the occurrence of Helmholtz resonance caused by the air flow S passing through the gap 5, thereby preventing the generation of abnormal noise. In particular, since it has an opening H that opens toward the rear of the vehicle, there is no chance that the vortex generated at the end Ea of the shield outer 1A will interfere with the end Eb of the shield inner 1B, and therefore the occurrence of Helmholtz resonance caused by the air flow S can be more reliably prevented.

[0025] The front grill structure according to the present invention is not limited to the configurations of the above-described embodiments, and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0026] 1 Front grille 1A Shield Outer 1B Shield Inner 1C Containment Space 5. Gap Ea End of the shield outer Eb End of the shield inner H opening M Vehicle body

Claims

1. A front grille structure including a shield outer serving as a design surface and a shield inner disposed on the back side of the shield outer, a gap communicating in the vehicle front-rear direction is provided between the periphery of the front grille and the vehicle body, A front grill structure characterized in that, at the periphery of the front grill, an end of the shield inner is offset toward the center of the grill more than an end of the shield outer.

2. a space for accommodating devices is provided between the shield outer and the shield inner, and an opening communicating with the space is provided between an end of the shield outer and an end of the shield inner; 2. The front grill structure according to claim 1, wherein the opening is spaced from the gap toward the center of the grill.

3. a space for accommodating devices is provided between the shield outer and the shield inner, and an opening communicating with the space is provided between an end of the shield outer and an end of the shield inner; 2. The front grill structure according to claim 1, wherein the opening is open toward the rear of the vehicle.

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