JPH10181629A - Fuel tank support structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a fuel tank from being deformed and floor vibrations from being increased by a change in inner pressure. SOLUTION: A plurality of cross members 7, 11 each of which joins right and left side members 3, 5 and the right and left members are provided under the floor panel of a vehicle body. A fuel tank 1 is disposed under the floor panel. The front and rear corners of the fuel tank 1 are supported by the right and left side members 3, 5 or a cross member 11. A tank mounting member 31 which is disposed in at least one side of the front and rear side parts of the fuel tank 1, apart from the floor panel, along the direction of vehicle width under the floor panel and both ends of which are fixed to the side members 3 and 5, is provided to support at least one central side part in the direction of vehicle width of the front and rear parts of the fuel tank 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a support structure for supporting a fuel tank below a floor panel in a four-wheel drive vehicle or the like.

[0002]

2. Description of the Related Art As a conventional tank support structure of this type, there are, for example, those shown in FIGS. 5 and 6, and those described in Japanese Utility Model Laid-Open Publication No. Hei 6-27276.

FIGS. 5 and 6 show a support structure of a fuel tank 1 in an FF-based (front engine, front drive base) 4WD vehicle (four-wheel drive vehicle). Is what I saw. The fuel tank 1 is of a so-called saddle type, as can be seen with reference to FIG. The fuel tank 1 is supported on the vehicle body at a rigid place so as not to be deformed in order to have durability against the internal fuel pressure. That is, the fuel tank 1 is supported by four points on the four front and rear corners and one point on the front center. This is because the fuel tank 1 has a large deformation on the center side due to a change in the internal pressure, and the deformation can be suppressed by supporting the center on the vehicle body side. More specifically, below the floor panel 2 of the vehicle body, left and right side members 3, 5 and a plurality of cross members 7, 9, 11 for connecting the left and right side members 3, 5 are provided. 7, 9, 11 are fixed to the lower surface of the floor panel 2 by welding or the like. 13 and 15 are left and right side sills.

[0004] Corresponding to the four front and rear corners of the fuel tank 1, front members 1 and 5 are attached to side members 3,5.
7 and 19 are the rear left and right brackets 2
1, 23 are fixed, and the brackets 17, 19, 21,
The flange portion 25 of the fuel tank 1 is abutted against the bottom 23 from below, and is fastened and fixed by a bolt nut 27. The flange portion 25 is provided with an enlarged portion 25a at the center of the front portion of the fuel tank 1. The enlarged portion 25a is provided at the center of the cross member 7 located on the front side of the fuel tank 1 in the vehicle width direction with a bolt and nut. It is fastened and fixed by 27. That is, by stopping at the four points on the four front and rear corners and the one point on the front center side as described above, deformation of the fuel tank 1 with respect to changes in the internal pressure of the fuel tank 1 can be suppressed.

On the other hand, there is also a demand for supporting the fuel tank 1 from the viewpoint of vehicle body vibration.

Generally, in a monocoque vehicle body of a four-cylinder vehicle, the body skeleton, for example, the side members 3 and 5 during idle rotation is set.
Is in a vibration mode as seen from the side in the vehicle width direction as shown by a broken line in FIG. 7A. In such a vibration mode, if the fuel tank 1 can be arranged at the vibration node point 29 as shown in FIG. 7B, the fuel tank 1 is prevented from vibrating in response to the vehicle body vibration. Therefore, it is possible to suppress an increase in vehicle body vibration.

[0007]

However, 4WD
When the structure of the suspension device is increased like a car, the fuel tank 1 must be displaced forward, and the fuel tank 1 must be arranged at the antinode of vibration as shown in FIG. In some cases, the structure must be used. In such a support structure, the fuel tank 1 vibrates greatly with respect to the vibration mode of the side members 3, 5 and the like at the time of idle rotation. From the central connection point, FIG.
Vibration is transmitted to the center side of the cross member 7 shown in FIG.
As described above, a large bending vibration of the cross member 7 having relatively low rigidity is induced, and there is a possibility that the floor vibration is greatly increased.

Accordingly, an object of the present invention is to provide a fuel tank support structure capable of suppressing floor vibration while suppressing the deformation of the fuel tank with respect to the internal pressure.

[0009]

According to a first aspect of the present invention, a vehicle includes a left and right side member below a floor panel of a vehicle body, and a plurality of cross members connecting the left and right side members. A fuel tank is disposed, four front and rear corners of the fuel tank are supported by the left and right side members or the cross member, and at least one side of the front and back of the fuel tank is separated from the floor panel. A tank mount member is provided below the floor panel along the vehicle width direction and both ends are fixed to the left and right side members. At least one of the front and rear portions of the fuel tank is provided on the tank mount member. The center side is supported.

Therefore, the fuel tank is supported by the front and rear four corners supported by the left and right side members or the cross member, and at least one of the front and rear portions in the vehicle width direction is supported by the tank mount member. Even if the tank is a saddle-type tank or the like, deformation due to a change in the internal pressure can be largely suppressed. In addition, the tank mount member is separated from the floor panel, and its left and right ends are fixed to the left and right side members. Therefore, the fuel tank is located at the antinode of the vibration mode during idle vibration of the side member or the like. Even in such a case, the vertical vibration of the tank is received by the tank mount member, and transmission to the floor panel side can be suppressed.

According to a second aspect of the present invention, there is provided the fuel tank supporting structure according to the first aspect, wherein a center bracket having a downward fastening surface is fixed to the tank mount member,
The fuel tank is characterized in that a flange portion of the fuel tank is fastened and connected to a fastening surface of the central bracket.

Therefore, in addition to the operation of the first aspect of the present invention, the front flange portion of the front portion of the fuel tank in the vehicle width direction is abutted against the downward fastening surface of the central bracket fixed to the tank mount member. can do.

According to a third aspect of the present invention, there is provided the fuel tank supporting structure according to the second aspect, wherein the tank mount member is disposed at a front side of the fuel tank.

Therefore, in addition to the effect of the second aspect of the invention, the center portion in the vehicle width direction of the fuel tank can be supported by the tank mount member disposed on the front side of the fuel tank.

According to a fourth aspect of the present invention, there is provided the fuel tank support structure according to the third aspect, wherein the left and right side members have downward fastening surfaces corresponding to the front left and right corners of the fuel tank. The front left and right brackets are fixed, and the rear left and right brackets having downward fastening surfaces are fixed to the cross members located on the rear side of the fuel tank corresponding to the rear left and right corners of the fuel tank. It is characterized in that the flange portion is fastened and joined by abutting the fastening surfaces of the front, rear, left and right brackets.

Therefore, in addition to the function of the third aspect of the present invention, the fuel tank includes a front left and right bracket having a flange fixed to the left and right side members, and a rear left and right bracket fixed to the cross member located at the rear side of the fuel tank. A fastening connection can be made by abutting each fastening surface from below.

[0017]

According to the first aspect of the present invention, by supporting the four points at the four front and rear corners of the fuel tank and at least one of the front and rear parts on the center side in the vehicle width direction, it is possible to prevent the internal pressure of the fuel tank from changing. Even so, the deformation can be reliably suppressed. Further, even when the fuel tank is located at the antinode of the vibration mode during idle vibration of the side member or the like, the vibration of the fuel tank is received by the tank mount member, and transmission to the floor panel side is greatly suppressed. Therefore, it is possible to reliably control the increase in vibration.

According to the second aspect of the invention, in addition to the effects of the first aspect of the invention, it is possible to easily attach the tank mount member to the tank mount member by fastening.

According to the third aspect of the present invention, in addition to the effect of the second aspect of the present invention, the center portion in the vehicle width direction can be supported by the tank mount member at the front side of the fuel tank, and the fuel tank is controlled by the internal pressure of the fuel tank. While reliably suppressing deformation, vibration of the fuel tank during idling vibration is reliably received by the tank mount member, and vibration of the floor panel can be reliably suppressed. In particular, the front side of the fuel tank is closer to the antinode of idle vibration, and by supporting this part of the fuel tank, idle vibration can be more effectively suppressed.

According to the fourth aspect of the present invention, in addition to the effects of the third aspect of the present invention, the fuel tank can be easily attached / detached by the fastening connection, thereby facilitating attachment or maintenance.

[0021]

1 to 3 show an embodiment of the present invention. FIG. 1 is a perspective view showing a part of a notch, FIG. 2 is a plan view showing a part of a notch, and FIG. FIG. 3 is an enlarged cross-sectional view taken along line III-III of FIG. 2. Note that components corresponding to the structures shown in FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 1 to 3, a tank mount member 31 is provided on the front side of the fuel tank 1. The tank mount member 31 is arranged side by side behind the cross member 7 located on the front side of the fuel tank 1, is separated from the floor panel 2 with a gap downward, and is disposed below the floor panel 2. It is arranged along the vehicle width direction on the side.

The tank mount member 31 has a substantially rectangular closed cross-sectional structure formed by folding a single plate, and its left and right ends are joined to the left and right side members 3 and 5. The left and right ends of the tank mount member 31 are connected to the side members 3 via brackets or the like.
5 can also be fixed.

A center bracket 33 is fixed to a center portion of the tank mount member 31 in the vehicle width direction. The central bracket 33 is composed of a bottom wall 33a and front and rear walls 33.
b and 33c, the front and rear walls 33b and 33c are fixed to the front and rear surfaces 31a and 31b of the tank mount member 31 by welding or the like, and the bottom wall 33a is provided with a downward fastening surface 33d. The flange 25 at the front of the fuel tank 1 is abutted against the fastening surface 33d of the center bracket 33 from the lower surface at the center in the vehicle width direction, and is fastened and fixed by the bolt nut 27. In addition, front and left and right brackets 17 and 19 and rear right and left brackets 21 and 23 are provided corresponding to the four front and rear corners of the fuel tank 1, respectively.
21 and 23 have an L-shaped cross section and have downward fastening surfaces. The flange portions 25 are fastened and fixed to the brackets 17, 19, 21 and 23 by bolts and nuts 27. Four points are fixed to the vehicle body. The front and rear four corners of the fuel tank 1
The front side is supported by the cross member 9 and the rear side is supported by the side members 3 and 5, and both the front and rear sides are supported by the side members 3 and 5.
Alternatively, it can be supported by the cross members 7 and 11.

With this support structure, the front and rear four corners of the fuel tank 1 are firmly supported by the front and left and right brackets 17 and 19 and the rear and right and left brackets 21 and 23 on the left and right ends of the highly rigid side members 3 and 5 and the cross member 11. The front center side of the fuel tank 1 is
By being supported by the tank mount member 31 via the third member 3, even if there is a change in the internal pressure of the fuel tank 1, the deformation thereof can be largely suppressed.

Further, even when the fuel tank 1 is located at the antinode of the vibration mode at the time of the idle vibration of the side members 3 and 5, the vertical vibration of the fuel tank 1 causes the cross member 7 having relatively low rigidity in the vehicle width direction. There is no input to the central portion, and it can be reliably supported by the tank mount member 31. Therefore, it is possible to restrict the transmission of vibration directly from the tank mount member 31 separated from the floor panel 2 to the floor panel 2 side, and it is possible to significantly suppress floor vibration. In particular, the front center side of the fuel tank 1 is a side close to the antinode during idling vibration, and is supported by the tank mount member 31 to improve the support rigidity of the fuel tank 1, so that the idling vibration is more effective. Will be suppressed.

FIG. 4 illustrates the effect of the fuel tank support structure according to one embodiment of the present invention, and shows the vibration acceleration level of floor vertical vibration during idle vibration.
In FIG. 4, (A) shows a level corresponding to the structure of FIGS. 5 and 6, and (B) shows a level according to an embodiment of the present invention. And the shaded area indicates a decrease in level,
As shown in FIG. 4, the floor vertical vibration was greatly reduced.
Further, the fuel tank 1 is provided with brackets 17, 19,
Since it is fastened and fixed to the bolts 21, 23, and 33 by the bolts and nuts 27, the attaching and detaching work is extremely easy, and the mounting and maintenance become extremely simple. It is also possible to arrange the tank mount members 31 at the front and rear portions of the fuel tank 1 and fasten and fix both the front and rear center portions of the fuel tank 1 in the vehicle width direction to the front and rear tank mount members. Further, it is also possible to provide a tank mount member only on the rear side of the fuel tank 1 and to fix the center of the rear side of the fuel tank 1 in the vehicle width direction to the tank mount member.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an essential part according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of a cutout of the same part.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 2;

FIG. 4 is a graph showing a change in floor vertical vibration.

FIG. 5 is a plan view of a waist according to a conventional example.

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

7 (a) shows a vibration mode of a side member or the like during idling rotation, FIG. 7 (b) shows a state in which a fuel tank is arranged near a node of the vibration mode,
(C) is an explanatory view showing a state in which the fuel tank is arranged on the antinode of the vibration mode.

FIG. 8 is a schematic diagram illustrating bending vibration of a cross member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel tank 2 Floor panel 3, 5 Side member 7, 11 Cross member 17 Front left bracket 19 Front right bracket 21 Rear left bracket 23 Rear right bracket 25 Flange part 27 Bolt nut 31 Tank mount member 33 Central bracket

Claims (4)

[Claims] 1. A vehicle, comprising: a left and right side member on a lower side of a floor panel of a vehicle body; and a plurality of cross members for connecting the left and right side members. A fuel tank is disposed on a lower side of the floor panel. The four corners of the fuel tank are supported by the left and right side members or the cross member. At least one of the front and rear portions of the fuel tank is separated from the floor panel, and the lower side of the floor panel extends along the vehicle width direction. And a tank mount member having both ends fixed to the left and right side members, and the tank mount member supports at least one of the front and rear portions of the fuel tank in the vehicle width direction central side portion. Fuel tank support structure. 2. The fuel tank support structure according to claim 1, wherein a central bracket having a downward fastening surface is fixed to the tank mount member, and the fuel tank flange is attached to the central bracket. A support structure for a fuel tank, wherein the fuel tank is fastened and joined to the fastening surface. 3. The fuel tank support structure according to claim 2, wherein the tank mount member is disposed at a front side of the fuel tank. 4. The support structure for a fuel tank according to claim 3, wherein front left and right brackets having downward fastening surfaces are fixed to the left and right side members corresponding to front left and right corners of the fuel tank. A rear left and right bracket having a downward fastening surface is fixed to a cross member located on the rear side of the fuel tank corresponding to the rear left and right corner of the fuel tank, and the front and rear flanges of the fuel tank are A support structure for a fuel tank, wherein the fuel tank is fastened and joined to the fastening surfaces of the left and right brackets.