Fuel tank mounting structure

Abstract

To provide a fuel tank attachment structure which can reliably satisfy required fire-resistance performance with a simple structure.SOLUTION: A fixing part which fixes a fuel tank to a vehicle body includes a rubber bush (a separation member) which separates the fuel tank from the vehicle body when the fixing part is exposed to a flame and its temperature increases. Thus, when the fixing part is exposed to a flame, the rubber bush deforms to separate the fuel tank from the vehicle body.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an attachment structure of a fuel tank.

Background Art

[0002] Patent Document 1 discloses an attachment structure of a general resin fuel tank to a vehicle body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For such a fuel tank, for example, a fire resistance test is obligatorily carried out according to safety standards. In the fire resistance test, for example, with the fuel tank attached to the vehicle body, the bottom surface side is exposed to flames for a predetermined time to confirm that no fuel leakage occurs.

[0005] In Patent Document 1, there is no specific description regarding a structure that satisfies the fire resistance test, but an attachment structure of a fuel tank with even higher fire resistance performance is required.

[0006] An object of the present disclosure is to provide an attachment structure of a fuel tank that can surely satisfy required fire resistance performance with a simple structure.

Means for Solving the Problems

[0007] In order to solve the above-described problems and achieve the object, the present disclosure is an attachment structure of a fuel tank having a fixing portion for fixing the fuel tank to a vehicle body, wherein the fixing portion A fixing member that fixes the fuel tank to the vehicle body, and is installed between the fixing member and the fuel tank, and has is provided with a detachment member that detaches the fuel tank from the vehicle body when the temperature of the fixing portion rises due to being exposed to flames. , has flexibility, and a slit is formed in a portion that contacts the fixing member This is the attachment structure of the fuel tank.

Advantages of the Invention

[0008] According to the present disclosure, a simple structure can surely satisfy the required fire resistance performance.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0010] With reference to the accompanying drawings below, the mounting structure of the fuel tank according to the embodiment will be described.

[0011] (Mounting Structure of Fuel Tank) Using FIGS. 1 and 2, the mounting structure of the fuel tank 10 will be described. FIG. 1 is a view showing an example of the bottom view of the fuel tank according to the present embodiment. FIG. 2 is a view showing an example of the side view of the fuel tank according to the present embodiment.

[0012] For the sake of explanation, a coordinate system XYZ shown in FIG. 1 is defined. The X-axis is the direction along the short side of the fuel tank 10, the Y-axis is the direction along the long side of the fuel tank 10, and the Z-axis is the thickness direction of the fuel tank 10. Note that the fuel tank 10 is made of resin.

[0013] The fuel tank 10 is fixed to a vehicle body (not shown in FIG. 1) at a plurality of locations in the Y-axis direction by the tank bands 12a and 12b. Further, the fuel tank 10 is fastened to a fuel tank bracket 20 on the vehicle body side at the fixing portion 30. Details of the structure of the fixing portion 30 will be described later (see FIGS. 3 and 4).

[0014] FIG. 2 is a side view of the fuel tank 10 as viewed from the negative X-axis side. The fuel tank 10 is fastened to a vehicle body (not shown) by the above-described tank band 12a, tank band 12b, and fixing portion 30.

[0015] (Detailed structure of the fixing portion) The detailed structure of the fixing portion 30 will be described with reference to FIGS. 3 and 4. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 4 is a view showing an example of the peripheral structure of the fixing portion provided in the fuel tank according to the present embodiment.

[0016] As shown in FIG. 3, the fixing portion 30 includes an iron collar 31, a rubber bush 32, and a bolt 34.

[0017] The iron collar 31 is a cylindrical member made of iron. The iron collar 31 prevents a decrease in the fastening force due to changes over time when the resin-made fuel tank 10 and the fuel tank bracket 20 are fastened with the bolt 34.

[0018] The rubber bush 32 is a cylindrical bush that surrounds the outer periphery of the iron collar 31. The rubber bush 32 has flexibility, and the outer peripheral portion of the rubber bush 32 fits into the fixing hole 11 of the fuel tank 10. Further, the above-described iron collar 31 is inserted into the inner peripheral surface of the rubber bush 32. A plurality of slits 33 are formed in the inner peripheral surface of the rubber bush 32. The slits 33 are provided to reduce the contact area between the rubber bush 32 and the iron collar 31.

[0019] The bolt 34 is inserted into the iron collar 31 from the bottom side of the vehicle body and fastened to the screw hole 21 formed in the fuel tank bracket 20. Thereby, the fuel tank 10 is fixed to the vehicle body. Note that the bolt 34 is an example of the fixing member in the present disclosure.

[0020] When heat is applied to the rubber bush 32, such as by exposing it to a flame, it softens, causing the fuel tank 10 to detach from the fixing portion 30. In particular, since the rubber bush 32 of the present embodiment is formed with a slit 33, the rubber bush 32 is more likely to deform when heat is applied. Note that the rubber bush 32 is an example of the detachment member in the present disclosure. The detachment member is not limited to the rubber bush 32, and any member having flexibility and thermoplasticity can be used instead of the rubber bush 32.

[0021] As shown in FIG. 4, notch holes 36 are formed around the fixing portion 30. In the example of FIG. 4, three notch holes 36a, 36b, and 36c are formed. The notch holes 36a, 36b, and 36c facilitate the detachment of the fuel tank 10 from the fixing portion 30 by promoting the deformation of the fixing portion 30 when heat is applied to the fuel tank 10. Note that instead of forming the notch holes 36, thinning the portion of the notch holes 36 can achieve the same effect.

[0022] (Behavior of the fuel tank when heat is applied) The behavior of the fuel tank of the present embodiment when heat is applied will be described with reference to FIGS. 5 and 6. FIG. 5 is a diagram for explaining the behavior of the fuel tank of the present embodiment during a fire resistance test. FIG. 6 is a diagram showing an example of the state of the fixing portion when the fuel tank has detached.

[0023] FIG. 5 shows a state in which a fire resistance test is being performed by exposing the bottom surface of the fuel tank 10 filled with fuel 13 to flames F1, F2, F3, and F4. Flame F1 is heating the end portion R1 of the fuel tank 10. Flames F2 and F3 are heating the central portion R2 of the fuel tank 10. And flame F3 is heating the end portion R3 of the fuel tank 10.

[0024] At this time, since the fuel 13 is injected into the fuel tank 10, even if the central portion R2 of the fuel tank 10 is exposed to the flame and the temperature of the fuel tank 10 rises, the heat is taken away by the fuel 13, so the temperature of the fuel tank 10 does not rise so much.

[0025] On the other hand, for the end portions R1 and R3 of the fuel tank 10, since the flame hitting the bottom of the fuel tank 10 wraps around above the fuel tank 10, the upper part of the fuel tank 10 is heated. Since the upper part of the fuel tank 10 is not filled with the fuel 13, the surface temperature of the fuel tank 10 rises, and the resin fuel tank 10 deforms and sags downward (in the negative Z-axis direction).

[0026] At this time, the rubber bush 32 (detachment member) forming the fixing portion 30 deforms due to heat and detaches the fuel tank 10 from the fuel tank bracket 20. Therefore, as shown in FIG. 5, the bolt 34 remains fastened to the fuel tank bracket 20.

[0027] Also, the end portions of the sagged fuel tank 10 are in a state of being heated by the inner flame which is the region inside the flames F1 and F4. The inner flame has a lower temperature than the outer flame which is the region outside the flame. Also, since the fuel 13 is injected into the fuel tank 10, the end portions of the sagged fuel tank 10 will not deform further even if they are exposed to the flames F1 and F4. Also, no holes will be formed in the fuel tank 10.

[0028] FIG. 6 shows a state where the fuel tank 10 has detached from the fuel tank bracket 20. As shown in FIG. 6, only the iron collar 31 and the bolt 34 of the fixing portion 30 remain fastened to the fuel tank bracket 20. And the rubber bush 32 (not shown in FIG. 6) deforms due to the temperature rise caused by being heated by the flame and detaches from between the fuel tank 10 and the iron collar 31. Then, since the diameter of the fixing hole 11 provided in the fuel tank 10 is larger than the diameter of the iron collar 31, as shown in FIG. 6, the fuel tank 10 is in a state of having detached from the fuel tank bracket 20.

[0029] (Advantages and effects of the embodiment) As described above, the mounting structure of the fuel tank 10 according to the present embodiment is a mounting structure of a fuel tank having a fixing portion 30 that fixes the fuel tank 10 to the vehicle body. The fixing portion 30 includes a rubber bush 32 (detaching member) that detaches the fuel tank 10 from the vehicle body when the fixing portion 30 is exposed to a flame and the temperature rises. Therefore, since the fuel tank 10 deformed on the bottom surface side by the flame can be reliably detached from the vehicle body, it has a simple structure and can surely satisfy the required fire resistance performance.

[0030] Further, in the mounting structure of the fuel tank 10 according to the present embodiment, the rubber bush 32 (detaching member) is installed between a bolt 34 (fixing member) that fixes the fuel tank 10 to the vehicle body and the fuel tank 10. Therefore, the fuel tank 10 can be reliably detached from the vehicle body.

[0031] Further, in the mounting structure of the fuel tank 10 according to the present embodiment, the rubber bush 32 (detaching member) has flexibility. Therefore, even if the sizes of the fixing holes 11 formed in the fuel tank 10 are different, the fuel tank 10 can be fixed to the vehicle body with the same bolt 34.

[0032] Further, in the mounting structure of the fuel tank 10 according to the present embodiment, at least a part of the peripheral edge of the rubber bush 32 (detaching member) of the fuel tank 10 is provided with a notch hole 36 or has a thin-walled structure. Therefore, the fuel tank 10 can be more reliably detached from the vehicle body.

[0033] The embodiments of the present invention have been described above. However, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. This novel embodiment can be implemented in various other forms. Also, various omissions, replacements, and changes can be made without departing from the gist of the invention. Further, this embodiment is included in the scope and gist of the invention and is included in the invention described in the claims and the equivalent scope thereof.

Description of Symbols

[0034] 10 Fuel tank 11 Fixing hole 12a, 12b Tank band 13 Fuel 20 Fuel tank bracket 21 Screw hole 30 Fixing part 31 Iron collar 32 Rubber bush (detachment member) 33 Slit 34 Bolt (fixing member) 36, 36a, 36b, 36c Notch hole F1, F2, F3, F4 Flame R1, R3 End part R2 Central part

Claims

1. An attachment structure of a fuel tank having a fixing portion for fixing the fuel tank to a vehicle body, wherein the fixing portion includes a fixing member for fixing the fuel tank to the vehicle body, and a detachment member that is disposed between the fixing member and the fuel tank, has flexibility, and has a slit formed in a portion thereof that contacts the fixing member, and is configured to detach the fuel tank from the vehicle body when the fixing portion is exposed to a flame and the temperature rises. An attachment structure of a fuel tank.

2. At least a part of a peripheral edge portion of the fuel tank of the detachment member is provided with a notch hole or has a thin-walled structure. The attachment structure of a fuel tank according to Claim 1.

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