JPH0514892Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a resin fuel tank for vehicles.

[Prior Art] Recently, resin-made fuel tanks have come to be used for vehicles and the like from the viewpoint of weight reduction.

When the fuel tank is made of resin, there is a problem in that it has low rigidity unlike conventional steel plate tanks, so it deforms significantly when the inside becomes negative pressure. For example, in the case of an ultra-high molecular weight polyethylene tank with an average wall thickness of about 4.5 mm, the pressure difference between the inside and outside is 0.1 Kg/cm ²
The amount of deformation reached 40 to 80 mm in negative pressure tests.

Such a large amount of deformation makes it difficult to adopt a suction structure such as that used in steel plate tanks. In other words, for steel plate tanks, secure a gap of, for example, 5 to 7 mm between the suction pipe suction port and the tank bottom, and then fix the suction pipe to the top wall of the tank to prevent water that collects at the bottom from being sucked in. However, if the amount of deformation is large as described above, problems arise such as the suction pipe's suction port gets stuck on the bottom of the tank, which hinders fuel suction.

On the other hand, a bump-full plate is provided in the fuel tank in order to prevent interference noise (so-called chap chip sound) from occurring due to swinging of the fuel.

In the case of steel plate tanks, a separately manufactured buttful plate is installed inside the tank, but resin tanks are generally formed by blow molding, so
It is difficult to insert and mold the buttful plate inside.

Therefore, when blow molding a resin fuel tank, a buttful plate is integrally molded. For example, in Japanese Utility Model Application Publication No. 56-171337, as shown in FIGS. 4 and 5 (cross-sectional view taken along the Z-Z line in FIG.
From 22 to 23, respectively, the full plates 23a and 23
It has been proposed to form a continuous buttful plate 23 by forming b and fusing their tips to each other. 24 indicates a fused portion.

[Problems to be Solved by the Invention] In the conventional resin tank, the tips of the buttful plates 23a and 23b extending from the opposing wall are fused to each other, so that the tank also functions as a reinforcing wall. Therefore, the suction structure in the steel plate tank described above can be adopted.

However, since the baffle plate 23 is a large hollow flat plate, there is a problem in that the tank capacity is sacrificed accordingly. Furthermore, full plates 23a, 23 extending from the opposing wall
If b is fused at its tip, there is a problem in that the tank is deformed upon collision, which applies stress to the fused portion in the direction of splitting, making it more likely to cause cracks.

In view of the above points, it is an object of the present invention to provide a fuel tank structure that is easy to blow mold while ensuring rigidity.

[Means for Solving the Problems] The present invention is a resin fuel tank for a vehicle molded by blow molding, which includes a tank body and a substantially conical shape extending from opposing walls of the body so as to face each other. The present invention relates to a resin fuel tank for a vehicle, which is formed of trapezoidal ribs and is integrally molded with a predetermined distance between the tips of the opposing ribs.

[Function] The tips of the substantially truncated conical ribs extending from the opposing walls of the tank body are normally separated from each other, but when the opposing walls of the tank body deform inward during negative pressure, the tips of the ribs separate from each other. touches,
Further deformation is avoided.

[Example] Next, the present invention will be explained based on the drawings.

Fig. 1 is a perspective view showing one embodiment of the fuel tank of the present invention, Fig. 2 is an enlarged sectional view taken along the line X-X, and Fig. 3
The figure is an enlarged sectional view taken along YY line.

In the drawings, reference numeral 1 denotes a tank body, and substantially truncated conical ribs 4 and 5 extend from opposing walls 2 and 3 of the tank body, respectively, so as to face each other. A predetermined distance h is provided between the tips of the ribs 4 and 5. The ribs 4 and 5 are integrally formed when the tank body 1 is blow-molded.

Reference numeral 10 denotes a fuel injection pipe, which is usually integrally molded when the main body 1 is blow molded. Reference numeral 11 denotes a suction pipe, which is inserted through an insertion hole opened after blow molding, and then fixed to the tank wall 2 at its upper end.

In the fuel tank of the present invention, the tips of the ribs 4 and 5 are normally spaced apart from each other by a distance h, but when the opposing walls 2 and 3 are pushed in opposite directions and dented during negative pressure. , the tips of the ribs 4 and 5 come into contact with each other, and the tank body 1 no longer deforms. Therefore, if the distance h between the rib tips is made smaller than the distance H between the suction port of the suction pipe 11 and the bottom surface 3 of the tank, there is no risk that the suction port of the suction pipe 11 will hit the bottom surface 3 during negative pressure. Suction structure can be adopted.

Further, the ribs 4 and 5 are approximately truncated conical,
The area and volume are much smaller than the conventional buff-full plate. Therefore, rib 4,
The amount of decrease in tank capacity due to the provision of 5 is small. Furthermore, since the force received when the fuel swings is smaller than that of a full plate, the bases of the ribs 4 and 5 may suffer fatigue failure even though the tips of the ribs 4 and 5 are not fused together. No problems arise. Moreover, if the tips of the ribs 4 and 5 are not fused together, problems such as cracks occurring in the fused portion due to collisions as in the conventional example can be avoided.

It also has the effect of reducing interference noise generated by swinging of the fuel.

In order to integrally mold the ribs 4 and 5 during blow molding, a mold provided with projections corresponding to the ribs 4 and 5 may be used for blow molding. Because of this formation method, the ribs 4 and 5 have hollow interiors.

The ribs 4 and 5 have a substantially truncated conical shape with a large base and a taper, but the ribs may have at least a draft angle that facilitates release from the mold. If the tank capacity is about 40 to 50,
Usually, the outer diameter of the base is about 15 to 30 mm, and the outer diameter of the tip is about 5 to 20 mm.

The cross-sectional shape of the ribs 4 and 5 is substantially circular, and the substantially circular shape includes an ellipse, a polygon of more than a pentagon, and especially a polygon of more than a hexagon. The cross-sectional shape of the ribs 4 and 5 is approximately circular, which is advantageous for blow molding and also because it reduces the resistance that the ribs receive when the fuel swings.

The distance h between the tips of the ribs 4 and 5 is usually 2~
It is said to be about 10mm. If the distance h is smaller than the above range, the tips of the ribs will be welded to each other due to process capacity, making it impossible to achieve the objective. One side interval h
If it is larger than the above range, the deformation of the main body 1 will become too large during negative pressure, which is not preferable. Furthermore, it becomes difficult to adopt a suction structure such as that used in the steel plate tank described above.

The number of ribs 4 and 5 is the tank capacity, tank body 1
Although it depends on the wall thickness of the tank, the tank capacity is 30~
In the case of about 60, about 2 to 6 pairs are provided.

Any conventional molding resin can be used for the fuel tank of the present invention, such as polypropylene, polyamide, ultra-high molecular weight polyethylene, etc., as appropriate.

[Effect of the invention] The tips of the ribs extending from opposite walls of the tank body come into contact during negative pressure, preventing further deformation. Therefore, a suction structure in a steel plate tank can be adopted.

The ribs have a substantially truncated conical shape, and because the force applied to the fuel when swinging is small, durability is excellent even though the tips of the ribs are not connected to each other.

Since the tips of the ribs are separated from each other, problems such as cracks occurring in the fused portion due to collisions as in the conventional example can be avoided.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the resin fuel tank of the present invention, Fig. 2 is an enlarged sectional view taken along the line X-X, Fig. 3 is an enlarged sectional view taken along the line Y-Y, and Fig. 4 is an enlarged sectional view taken along the line Y-Y. A sectional view showing a conventional resin fuel tank, FIG. 5 is a sectional view taken along the line Z-Z. Main symbols in the drawing: 1...tank body, 2, 3...
...wall, 4,5...rib, h...space.

Claims (1)

[Scope of utility model registration request] A resin fuel tank for vehicles molded by blow molding, consisting of a tank body and substantially frustoconical ribs extending oppositely from opposite walls of the main body, and each of the opposing ribs having a A resin fuel tank for a vehicle that is integrally molded with a predetermined interval between the tips.