JP2507045B2 - Fuel tank structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a fuel tank structure made of synthetic resin suitable for automobiles.

(Prior Art) Conventionally, as shown in FIG. 5, a synthetic resin fuel tank is generally used to prevent deformation due to pressure when the tank is expanded.
The bottom surface 105 of the upper side recessed portion 103 recessed inward from the upper surface side central portion of the tank body 101 and the bottom surface 109 of the lower side recessed portion 107 recessed inward from the lower surface side central portion are butt-joined to each other, and the tank The structure that secures the strength of the substantially central portion of the main body 101 is adopted (as a similar structure, there is JP-A-60-118520).

(Problems to be Solved by the Invention) As described above, since the bottom surfaces 105 and 109 of the upper concave portion 103 and the lower concave portion 107 which secure the strength are integrally superposed and coupled, for example, the tank main body may be formed by a collision. When a large impact load is applied to 101, the joint area may be cracked in some cases. In this case, even if an excessive load is input, the upper side recess 103
Although this can be dealt with by making the lower concave portion 107 thicker, it is not desirable in terms of weight and cost because the entire tank body 101 becomes thicker because of integral molding.

Therefore, an object of the present invention is to provide a fuel tank structure that does not crack in the joint area even if an excessive load is input to the tank body by a simple device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the present invention, from the bottom surface of the first recessed portion that is recessed inward from the upper surface side of the tank body, and from the lower surface side The bottom surfaces of the second recesses that are recessed inward are separated from each other, and projections that project inside the tank body are provided on these bottom surfaces, and the projections are abutted and joined together.

(Operation) According to this fuel tank, since the bottom surface of the first recess and the bottom surface of the second recess are joined to each other via the protrusion, the strength of the tank main body is secured.

On the other hand, when an excessive load is input to the tank body, the protruding portion of the first recess and the protruding portion of the second recess are reasonably separated from each other when the tank body is deformed to avoid the input load.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings of FIGS. 1 to 5.

 In the figure, 1 indicates a tank body of the fuel tank 3.

The tank body 1 is made of synthetic resin and has an upper surface 1a.
The first concave portion 5 which is hollowed inward in a cylindrical shape is formed in the substantially central portion on the side.
Are integrally molded. In addition, a second recessed portion 7 that is recessed in a cylindrical shape inward is integrally formed in a substantially central portion on the lower surface 1b side of the tank body 1, and a bottom surface 5a of the second recessed portion 5 and a bottom surface of the second recessed portion 7 are formed.
A predetermined gap d is secured with 7a. Hemispherical projections 9 and 9 are integrally formed on the bottom surface 5a of the first recess 5 and the bottom surface 7a of the second recess 7, and the projections 9 and 9 are integrally joined in a butted state. .

FIGS. 4 (a), (b), (c), and (d) show the procedure for forming the tank body 1.

First, as shown in Fig. 4 (a), the molding material (parison)
P is sent between a pair of outer molds 15 and 15 which have the 1st crevice formation part 11 and the 2nd crevice formation part 13 which are separated mutually also at the time of mold matching.

Next, as shown in Fig. 4 (b), the molding material (parison)
The outer molds 15 and 15 are closed from the left and right with respect to P. At this time, since the first recessed portion forming portion 11 and the second recessed portion forming portion 13 are separated from each other, a predetermined gap d is secured in the parison P in this portion, and the parison P may stick to each other. Then, as shown in FIG. 4C, the blow pin B blows air into the parison P to shape the outer shape of the tank body 1.

Finally, as shown in Fig. 4 (d),
Is moved forward in the mold by the hydraulic device 19.19 to form the integrally joined protrusions 9. And
The adjustment of the joining strength of the protrusions 9 and 9 to be joined to each other can be freely changed by appropriately changing the size of the tip portion of the protrusion molding portion 17 and 17,
Easy to achieve.

Therefore, according to the tank body 1 molded as described above, the strength against pressure is ensured by the protrusions 9, 9 and the first recesses 5 and the second recesses 7 that are joined together.

Next, when an excessive load is input to the tank body 1, the input is deformed by the input, but at that time, since the joint areas of the projections 9 and 9 are small, the protrusions 9 and 9 are naturally separated to avoid the input load. Therefore, no crack occurs in the second recess 7.

[Advantages of the Invention] As described above, according to the fuel tank of the present invention,
The strength of the tank main body can be ensured by the protrusion of the first recess and the protrusion of the second recess that are joined together. Further, when an excessive load is input, the protrusions are separated from each other without difficulty, and thus it is possible to prevent the first recess and the second recess from being cracked.

[Brief description of drawings]

FIG. 1 is a sectional view of a fuel tank according to the present invention, FIG. 2 is an enlarged cross-sectional view showing a state where protrusions and protrusions are butted and joined, and FIG.
The figure is a perspective view of the tank body, and Fig. 4 (a) (b) (c)
(D) is an explanatory view showing a molding step, and FIG. 5 is a sectional view similar to FIG. 1 showing a conventional example. DESCRIPTION OF SYMBOLS 1 ... Tank main body 5 ... 1st recessed part 7 ... 2nd recessed part 9 ... Projection part

Claims (1)

(57) [Claims] 1. A bottom surface of a first recess recessed inward from an upper surface side of a tank main body and a bottom surface of a second recess recessed inward from a lower surface side of the tank main body are separated from each other, and the bottom surfaces of the first recessed portion are respectively provided inside the tank main body. A fuel tank structure, characterized in that a protruding portion is provided on the inner surface of each of the protruding portions, and the protruding portions are joined together.