JP2001206076A - Fuel tank made of synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel tank made of a synthetic resin formed so as to suppress HC permeation from a cutting plane even an opening for connecting sub-parts is provided. SOLUTION: This fuel tank made of the synthetic resin is formed by connecting the sub-parts comprising a part formed by gasoline barrier material in the opening provided to a tank main body formed by piling up the gasoline barrier material and general material. The sub-parts is connected to the tank main body by making an exposed surface of a gasoline barrier material part of the sub-parts continue from an exposed surface of a gasoline barrier material layer in a section of the opening of the tank main body. The gasoline barrier material layers of the tank main body and the sub-parts are thereby made continue from each other, and barrier properties are ensured even when a part of the general material is exposed to HC atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank made of synthetic resin, and more particularly to a fuel tank having a portion formed of a gasoline barrier material at an opening provided in a tank body formed by laminating a gasoline barrier material and a general material. The present invention relates to a synthetic resin fuel tank formed by connecting parts.

[0002]

2. Description of the Related Art There is an increasing tendency to use a fuel tank formed by blow molding a synthetic resin material since rust prevention and weight reduction are easy and high productivity can be obtained.

By the way, high-density polyethylene (hereinafter, referred to as HDPE) generally used for blow molding has low impermeability (hereinafter, referred to as barrier property) for hydrocarbons (hereinafter, referred to as HC), and thus prevents air pollution. From a standpoint, it is not suitable for use as is in a gasoline tank.

In order to suppress the permeation of HC, it is preferable to use a material having a high barrier property such as an ethylene vinyl alcohol copolymer (hereinafter referred to as EVOH), but such a so-called gasoline barrier material is relatively expensive. In addition, since the impact resistance is insufficient, it is difficult to say that forming the entire tank with a gasoline barrier material is practical in terms of manufacturing cost and strength. Therefore, a combination material in which a general material such as HDPE having a high impact resistance and a gasoline barrier material are laminated has been considered (see Japanese Patent Application Laid-Open No. 10-128888).

[0005]

However, the blow-molded fuel tank is provided with an opening for mounting a separately molded child part such as a filler neck or a breather pipe by secondary processing. When a laminated material is used, a cut surface of a general material is exposed on the inner peripheral surface of the opening. If the cut surface of the general material is exposed to the HC gas atmosphere in the fuel tank, the permeation of HC from the cut surface cannot be prevented.

[0006] The present invention has been devised to solve such problems of the prior art, and its main objects are as follows.
An object of the present invention is to provide a fuel tank made of a synthetic resin configured to be able to suppress the permeation of HC from a cut surface thereof even if an opening for connecting a child component is provided.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a gasoline barrier material formed in a tank body formed by laminating a gasoline barrier material and a general material. In a synthetic resin fuel tank formed by combining child parts provided with a gasoline barrier material layer in the cross section of the opening of the tank body, the exposed surface of the gasoline barrier material part of the child part is connected to the child part. Are combined. In this way, the gasoline barrier material layers of the tank body and the child component are continuous with each other, so that even if the general material is exposed to the HC atmosphere, the barrier properties are not impaired.

[0008] In particular, if the inner peripheral edge of the opening is chamfered at an obtuse angle with the outer surface of the tank body, and the mating opening fitting portion having an angle corresponding to the chamfering is provided on the child part, the opening diameter and the opening diameter can be reduced. The close contact between the two can be ensured by absorbing a dimensional error with the outer diameter of the child part.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a joint of a child part to a fuel tank constructed according to the present invention.

The tank body 1 is a laminated material that is bonded to each other with a barrier layer 1c made of a gasoline barrier material such as EVOH sandwiched between a pair of inner and outer main material layers 1a and 1b made of a general material such as HDPE. It is formed with.

An opening 3 for attaching a separately molded child part 2 such as a filler neck or a breather pipe is provided at an appropriate position of the tank body 1. This opening 3
Is cut off at right angles to the surface of the tank body 1.

The whole child part 2 is formed of a gasoline barrier material, and has a cylindrical shape that fits tightly on the inner peripheral surface of the opening 3 and has a flange 5 that can come into close contact with the periphery of the opening 3. It is formed at an appropriate position in the axial direction.

The tank main body 1 and the child part 2 are integrally connected by an appropriate adhesive.

According to this, the outer peripheral surface of the child component 2 made of a gasoline barrier material is directly joined to the portion 1s exposed on the inner peripheral surface of the opening 3 of the barrier layer 1c. Since the entire surface is covered with the child component 2, the cut surfaces of the main material layers 1a and 1b made of the general material do not have to be exposed to the HC gas atmosphere in the tank body 1.

FIG. 2 shows a second embodiment of the present invention. Since the tank body 1 is basically the same as the above, portions corresponding to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The child part 12 has a cylindrical shape that fits tightly into the opening 3 of the tank body 1, and has a flange 15 that can come into close contact with the periphery of the opening 3 near the lower end in FIG. Similarly to the tank body 1, it is formed of a laminated material in which a barrier layer 12c made of EVOH is sandwiched between a pair of inner and outer main material layers 12a and 12b made of HDPE. In addition, the barrier layer 12 c of the child component 12 has a portion located at the lower end thereof bent outward at a right angle, and the terminal end thereof is exposed to a fitting surface with respect to the opening 3.

The tank body 1 and the child part 12 are connected to each other by using an appropriate adhesive or by using an opening 3 of the tank body 1.
And the flange 15 are integrally joined by heat welding.

In this case, when the child component 12 is fitted into the opening 3 of the tank body 1, the barrier layer 1
The child part 12 is exposed to the portion 1s exposed on the inner peripheral surface of the opening 3 of FIG.
The end surface 12s of the barrier layer 12c exposed on the outer peripheral surface of the paired fitting portion is directly joined, so that the barrier layer 1c of the tank body 1 and the barrier layer 12c of the child component 12 are continuous with each other. Has become. Therefore, even if the cut surfaces of the main material layers 1a and 1b made of a general material are exposed on the inner peripheral surface of the opening 3, the HC gas in the tank body 1 does not need to permeate.

The child component 12 can be formed by a two-color molding method in which a barrier layer 12c formed in advance is inserted.

FIG. 3 shows a third embodiment of the present invention. The tank body 21 in this case has a two-layer structure in which the barrier layer 21c is formed only on the inner surface.

The child part 22 is provided with an opening 23 of the tank body 21.
A flange 25 is formed in the vicinity of the lower end in FIG. Then, similarly to the tank body 21, the barrier layer 22c is formed only on the inner peripheral surface. The lower end of the barrier layer 22c of the child component 22 is bent outward at a right angle to cover the lower end surface of the main material portion 22a, and the terminal end 22s is exposed to the fitting surface to the opening 23.

The tank body 21 and the child part 22 are
An appropriate adhesive is used, or the parts are integrally joined by heat welding between the periphery of the opening 23 of the tank body 21 and the flange 25.

In this case, the opening 2 of the tank body 21 is
When the child part 22 is fitted to the third part 3, the portion 21 s exposed on the inner peripheral surface of the opening 23 of the barrier layer 21 c of the tank body 21 is formed.
The end surface 22s of the barrier layer 22c exposed on the outer peripheral surface of the mating part of the child component 22 is directly joined to the tank body 21.
And the barrier layer 22c of the child component 22 are continuous with each other. Therefore, even if the cut surface of the main material layer 21a made of a general material is exposed on the inner peripheral surface of the opening 23, the HC gas in the tank body 21 does not need to permeate.

The barrier layers 21c and 22c are made of a main body portion 21 of a tank body and a child component which are formed of a general material in advance.
It can be formed by coating a molten gasoline barrier material on each inner surface of a.22a.

FIG. 4 shows a fourth embodiment of the present invention. In this case, the barrier layer 31c is formed only on the outer surface of the tank body 31.

The child part 32 is provided with an opening 33 of the tank body 31.
It has a cylindrical shape that fits tightly into the cylinder. A barrier layer 32c only on the outer peripheral surface similar to that of the tank body 31 is formed in a portion exposed outside the tank.

The tank body 31 and the child part 32 are
They are integrally connected by an appropriate adhesive.

In this case, the opening 3 of the tank body 31
When the child part 32 is fitted to the third part 3, the part 31 s exposed on the inner peripheral surface of the opening 33 of the barrier layer 31 c of the tank body 31 is formed.
Then, the barrier layer 32c on the outer peripheral surface of the child component 32 is directly joined, so that the barrier layer 31c of the tank body 31 and the barrier layer 32c of the child component 32 are continuous with each other. Therefore, the main material layer 31a made of a general material is formed on the inner peripheral surface of the opening 33.
Even if the cut surface is exposed, the HC gas in the tank body 31 does not need to permeate.

The barrier layers 31c and 32c are made of a main body portion 31 of a tank body and a child component which are formed of a general material in advance.
a.32a can be formed by coating a molten gasoline barrier material on each outer surface.

FIG. 5 shows a fifth embodiment of the present invention. In this case, since the tank body 1 is basically the same as the first embodiment, portions corresponding to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The opening 3 has a chamfer 4 formed at an obtuse angle with the outer surface of the tank body 1 over the entire circumference.

The child part 42 is entirely formed of a gasoline barrier material, and has a flange 4 at an appropriate position in the axial direction.
5 are formed. A tapered slope 6 having an angle corresponding to the chamfer 4 formed on the inner peripheral surface of the opening 3 is formed at the base of the flange 45. Thereby, the flange 45 is provided on the outer surface of the tank body 1 and the inner peripheral surface of the opening 3.
Can be closely related.

The tank main body 1 and the child component 42 are integrally joined with an appropriate adhesive. Here, since the bonding surfaces 4 and 6 are inclined at an equal angle, even if the mutual accuracy of the two is somewhat low, the closeness is not impaired.

As described above, the main material layer 1 having low barrier properties
The tapered slope 6 of the child component 42 made of the gasoline barrier material is directly bonded to the portion 1s of the gasoline barrier material layer 1c exposed between the inner surfaces of the openings 3 of the gasoline barrier material layer 1c. Of the main material layers 1a and 1b having low barrier properties do not need to be exposed to the HC gas atmosphere in the tank body 1 because the entire inner peripheral surface of the main body layer is covered with the child part 42 made of the gasoline barrier material. Becomes

[0036]

As described above, according to the structure of the first aspect of the present invention, the barrier layer portion exposed on the inner peripheral surface of the opening provided in the synthetic resin fuel tank formed of the laminated material has the following characteristics. Since the barrier layer portion of the fitted child component is connected, the permeation of HC from the cut surface of the opening is suppressed. Also,
If the configuration of claim 2 is added, the positioning of the child component with respect to the tank main body becomes easy, which is effective in improving productivity.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part showing a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part showing a third embodiment of the present invention.

FIG. 4 is a sectional view of a main part showing a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a main part showing a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank main body 1a, 1b Main material layer 1c Gasoline barrier layer 2 Child part 3 Opening 4 Chamfer 5 Flange 6 Tapered slope

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akihiro Yashima 1959-5 Oshiage, Ujiie-cho, Shioya-gun, Tochigi F-term in Yachiyo Kogyo Co., Ltd. F-term (reference) 3D038 CA04 CA15 CA22 CC14 CC20

Claims (2)

[Claims] 1. A synthetic resin fuel tank in which a child component having a portion formed of a gasoline barrier material is connected to an opening provided in a tank body formed by laminating a gasoline barrier material and a general material. Wherein the exposed part of the gasoline barrier material layer in the cross section of the opening of the tank body is connected to the exposed surface of the gasoline barrier material part of the child part to connect the child part to the tank body. Plastic fuel tank. 2. The method according to claim 1, wherein a chamfer having an obtuse angle with respect to an outer surface of the tank body is formed on an inner peripheral edge of the opening, and a mating opening fitting portion having an angle corresponding to the chamfer is provided on the child component. The fuel tank made of synthetic resin according to claim 1.