JPH08156617A - Fuel tank - Google Patents

Abstract

PURPOSE: To restrain flow noise caused by reacted wave of fuel with respect to a rear part, of a fuel tank effectively by a simple structure when a vehicle is decelerated. CONSTITUTION: A part near a center of a rear wail surface 14 in a vehicular fuel tank 10 is projected backward from its left and right end parts and also a center part of the tank is deeper than the left and right end parts and a baffle plate 17 hangs down internally from the rear wall surface 14 and an upper wall surface with a small space left between them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a liquid fuel tank mounted on a vehicle.

[0002]

2. Description of the Related Art During deceleration of a vehicle, liquid fuel in a fuel tank rapidly moves forward due to inertia, collides with a front wall surface and an upper wall surface front end of the fuel tank to generate an impact sound, and then bounces back. The reaction wave collides with the rear wall surface of the fuel tank and the rear wall of the upper wall surface, and further generates a flowing sound.
Conventionally, as shown in FIGS. 4 to 6, the fuel tank 1
A baffle plate 3 in which a plurality of small holes 2 of an appropriate size are opened at an appropriate position in the front part of the inside is hung from the upper wall surface 5 of the fuel tank 1 at a small distance from the front wall surface 4, The baffle plate 3 prevents the fuel from moving forward during deceleration of the vehicle to prevent the generation of abnormal noise.

However, when the amount of fuel in the fuel tank 1 becomes relatively small and the fuel level a drops to near the lower end of the baffle plate 3 as shown in the figure, the fuel is below the baffle plate 3 during deceleration of the vehicle. Through Figure 3
The front wall surface 4 of the fuel tank 1 as shown in FIG.
And the reaction wave which collided with the front end of the upper wall surface 5 and was then swept back also passed under the baffle plate 3, and the rear end portion of the fuel tank 1 and the rear end portion of the upper wall surface 5 like the fuel level c. Therefore, the effect of suppressing the fuel movement by the baffle plate 3 is reduced.

When the width of the fuel tank 1 is narrowed behind the relatively deep central portion as shown in the figure,
Since the recoil wave of the fuel to the rear is greatly amplified toward the narrowed central rear part, there is a problem that the generation of the flow noise at the rear part of the fuel tank 1 becomes particularly remarkable.

As a countermeasure against these problems, the baffle plate 3
May be extended to the lower side of the fuel tank 1, but in this case, a large load may act on the attachment portion of the baffle plate 3 on the upper wall surface of the fuel tank 1 and a crack may be generated there. It's not practical.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to effectively suppress the generation of flow noise due to the reaction wave of the fuel to the rear portion of the fuel tank when the vehicle is decelerated with a simple structure. .

[0007]

Therefore, the fuel tank according to the present invention is provided with a baffle plate that hangs from the upper wall surface so as to be spaced a small distance from the rear wall surface.

[0008]

As described above, since the baffle plate that hangs from the upper wall surface is installed so as to be spaced a small distance from the rear wall surface, when the fuel in the fuel tank moves forward due to its inertia during deceleration of the vehicle, Since the flow of the reaction wave to the rear is stopped by the baffle plate, the reaction wave is suppressed from colliding with the rear end portions of the rear wall surface and the upper wall surface of the fuel tank, and therefore the flow noise in the fuel tank is suppressed. Can be effectively reduced.

[0009]

Embodiments of the present invention will be specifically described below. 1 to 3, a fuel tank 10 mounted on a vehicle is entirely formed by welding an upper tank 11 and a lower tank 12 at respective flanges 13.
As shown in FIG. 1, the vicinity of the center of the rear wall surface 14 projects rearward from the left and right end portions, and as shown in FIG. 2, the central portion 15 is deeper than the left and right end portions and has an appropriate size. A baffle plate 17 having a plurality of small holes 16 at appropriate positions is hung from the upper wall surface 18 of the fuel tank 10 at a small distance from the rear wall surface 14, and the lower end of the baffle plate 17 extends to the upper part of the lower tank 12. It is supposed to arrive.

Therefore, when the vehicle decelerates, the liquid fuel in the fuel tank 10 rapidly moves forward due to inertia, and then the reaction wave rebounded is baffle plate installed at a small distance from the rear wall surface 14. The flow is stopped by 17, but in this case, in particular, the rear wall surface 14 of the fuel tank central portion 15 which is relatively deep projects rearward beyond the left and right end portions and has a narrow lateral width. Since the wave is greatly amplified toward the narrowed central portion 15, the reaction wave having the increased fuel level will surely collide with the baffle plate 17 hanging from the upper wall surface 18 of the fuel tank 10. The baffle plate 17 can effectively suppress the flow of the reaction wave and prevent the generation of flow noise.

Moreover, as described above, the partial rearward projecting shape of the fuel tank rear wall surface 14 amplifies the rearward reaction wave to increase the liquid level, so that the baffle plate 17
Can sufficiently suppress the reaction wave flow even if it is relatively small. Therefore, it is not necessary to form the baffle plate 17 in a large size, and the internal structure of the fuel tank 10 can be made relatively simple. You can

In the above embodiment, the baffle plate hangs down from the upper wall surface of the fuel tank. However, even if the baffle plate is constructed so as to stand up from the bottom surface of the fuel tank, the same operation as that in the above embodiment is performed. It is possible to produce an effect.

[0013]

In the fuel tank according to the present invention, since the baffle plate that hangs down from the upper wall surface is installed at a small distance from the rear wall surface, when the vehicle is decelerated, the fuel in the fuel tank moves forward due to its inertia. When moving to, the backflow of reaction waves is stopped by the baffle plate, and the reaction waves are prevented from colliding with the rear end portions of the fuel tank rear wall and upper wall surface. It is possible to effectively reduce the generation of flow noise in the vehicle and easily improve the riding comfort of the vehicle.

[Brief description of drawings]

FIG. 1 is a top view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a top view of a conventional device.

5 is a cross-sectional view taken along the line VV of FIG.

6 is a sectional view taken along the line VI-VI of FIG.

[Explanation of symbols]

 10 Fuel Tank 11 Upper Tank 12 Lower Tank 14 Rear Wall Surface 15 Central Part 17 Baffle Plate 18 Upper Wall Surface

Claims (5)

[Claims] 1. A fuel tank provided with a baffle plate that hangs from an upper wall so as to be spaced a small distance from the rear wall. 2. The fuel tank according to claim 1, wherein the fuel tank is formed of an upper tank and a lower tank, the baffle plate hangs down from the upper tank, and a lower end of the baffle plate is arranged in an upper part of the lower tank. 3. The fuel tank according to claim 1, wherein the baffle plate is installed so as to face a rear wall surface partly protruding rearward. 4. The fuel tank according to claim 3, wherein the baffle plate is installed facing a central portion of a rear wall surface projecting rearward from the left and right end portions. 5. The fuel tank according to claim 3 or 4, wherein the rearwardly projecting portion of the rear wall surface is formed deeper than at least one of the left and right end portions.