JPS63258217A - Resin filler tube - Google Patents

Abstract

PURPOSE:To reduce the amount of application materials by making trough depth of the sectional corrugation of a molding die shallower than other parts to a thick part corresponding position among crest parts of a tube bellows part, in case of a tube bearing the above caption for an automobile subjected to blow molding. CONSTITUTION:In case of sectional corrugated form parts 14A and 14B to be formed in a make mold 13B and a female mold 13B of a die 13, depth (b) of a trough part 14B1 of the female mold 13B is formed to be shallower (a>b) than depth (b) of a trough part 14A1 of the male mold 13A. When a cylindrical parison is mounted on position between these upper and lower molds 13A and 13B of the die 13 and subjected to blow molding, the trough part 14B1 of the female mold 13B is shallow so that extension value of the parison becomes lessened, and a crest part of a bellows part 10A is formed into thickness as compared with the side of the male mold 13A. With this constitution, only the required part can be formed into the thickness while keeping a bellows function, thus reduction in tube weight is well promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin filler tube, particularly to a resin filler tube for automobiles formed by a blow molding method.

[Prior Art] Conventionally, this type of resin filler tube has a bellows part in the middle of the tube, which improves workability by absorbing installation errors when installing it on the fuel tank body and the vehicle body side, and improves workability in the event of a vehicle collision. This function prevents the filler tube from being damaged due to misalignment between the fuel tank body and the vehicle body, which occurs when the fuel tank body and the vehicle body are misaligned.

This resin filler tube is formed using a blow molding method.

In other words, a cylindrical parison in a plastic state is placed between the split molds that are split in half vertically or horizontally! Then, both molds are tightened, one end is sealed with a jig, etc. to form a bag-like parison, and air is blown through the opening at the other end to form a roughly cylindrical resin filler to match the shape of the mold. They are forming tubes. Thus, the circular pipe portion and the bellows portion of the resin filler tube are formed concentrically.

[Problems to be Solved by the Invention] However, when molding a resin filler tube having a bellows part using the blow molding method as described above, the fifth
As shown in the figure, the forming process of the bellows part corresponds to the valley of the bellows of the cylindrical parison 5a when air is blown into the cylindrical parison 5a (indicated by the two-dot chain line) in the state of (a). Parts 5a, , 5a2 (mounted part 6 in mold 6)
0.6□) is the peak part of the mold 6. .

62, and then the part between the peaks 6I and 62 is extended to receive uniformly distributed pressure, resulting in the state 5b (indicated by the dashed line), and then finally the valley part 63 of the mold 6. It is press-molded along the shape of , resulting in the state 5C (shown by the solid line).

Therefore, as shown in FIG. 6, the resin filler tube 1
The wall thickness of the mountain part of the bellows part 1^, especially the top part IAc, was considerably thinner.

By the way, when used as a resin filler tube for an automobile fuel tank, for example, it is formed to meet the required conditions, but generally the fuel tank is installed under the floor of the automobile. Because of this, there are demands for durability against pebbles splashing during driving, that is, chipping resistance, and flame resistance against vehicle fires.

These requirements are particularly high on the fender side of a vehicle, and in order to meet these requirements, it is necessary to increase the wall thickness of the resin filler tube, but since the circular tube part and the bellows part are concentric, this requirement is not met. It was difficult to increase the thickness only on the high side. Therefore, if the wall of the bellows part is made thick to ensure the required strength, the entire resin filler tube becomes unnecessarily thick, requiring extra resin material, which also causes an increase in weight. was there.

There was also the problem that the absorbent function of the bellows part was also impaired.

The purpose of the present invention is to solve these conventional problems, increase the thickness only in the parts where it is necessary, and reduce the amount of material used, thereby reducing the weight while satisfying the absorption function and strength requirements of the bellows part. It is an object of the present invention to provide a resin filler tube that can reduce the amount of damage.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method in which a cylindrical parison is placed between split molds having a corrugated cross-sectional shape, and is formed by a blow molding method. In a resin filler tube with a bellows part, the depth of the trough of the corrugated cross-section of the mold corresponding to the thick-walled part of the peak part of the bellows part is made shallower than other parts, making it suitable for blow molding. It is characterized by being formed by

[Function] According to the present invention, the depth of the trough of the corrugated cross-sectional part of the mold corresponding to the part requiring wall thickness is formed shallower than other parts, and the blow molding is performed. The amount of stretching of the peak portion of the resin filler tube formed by the valley portion is reduced, and it is possible to prevent the resin filler tube from becoming extremely thin.

Therefore, the wall can be made thicker only in the necessary parts, and the rest can be made thinner, making it possible to obtain a resin filler tube with excellent strength while maintaining the absorption function of the bellows part.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an external perspective view of a resin filler tube to which the present invention is applied, where 10 is a resin filler tube, 11 is a resin filler tube;
is a fuel tank, and 12 is a hose that connects the two. The resin filler tube 10 has a circular tube part 10B and a bellows part 10.
It has ^.

Therefore, the height of the peak of the bellows portion 10A on the right side as shown in the first drawing, that is, on the fender side when mounted on the vehicle is different from the height of the peak on the opposite side, that is, on the inside of the vehicle and on the longitudinal direction of the vehicle. It is lower and thicker than the original.

A method of molding the resin filler tube 10 having such a bellows shape will be explained with reference to FIG. 2.

In the figure, 13 is a mold that is divided into halves vertically or horizontally. In this example, for convenience, upper mold 13A and lower mold 1 are used.
It is called 3B. The upper mold 13A and the lower mold 13B each have a wave-shaped section 148, 14B and a straight section 15A,
15B, but in the lower mold 13B, the valley portion 14B1 of the wave-shaped cross-sectional portion 14B is formed shallower than in the other molds. That is, as shown in the figure, in the upper mold 13A, the depth of the valley 14Al is a, whereas in the lower mold 13B, the depth of the valley 14Al is a.
Then, let b (a>b).

In addition, in this example, the cross-sectional wave-shaped portions 14A and 14
The peak portions 14A2 and 14B2 of B match the heights of the linear portions 15A and 15B, respectively.

A cylindrical parison in a plastic state is placed between the two molds 13A and 13B formed in this way, and both molds are tightened.
After sealing one end with a jig or the like to form a bag-like parison, air is blown through the opening at the other end.

Then, as described above with reference to FIG. 5, the parison is formed by forming the respective peaks 14A of both molds 13A and 13B.

14B2, and then uniformly distributed pressure acts on the valleys 14A+ and 14B+ between the peaks 14A2.1482.
The bellows portion 10A is formed along the wavy cross-sectional shape of the mold 13 while extending the portion facing the metal mold 13.

By the way, since the valley 14B on the lower mold 13B side is shallow, the extension stops midway, compared to the upper mold 13A side.
The mountain portion of the bellows portion 10A is formed thick.

The form of the first embodiment of the present invention formed in this manner is as shown in FIG. is an eccentric relationship. Further, a sectional view of this embodiment is shown in the second figure.

In this embodiment, since the lower die 13B side corresponds to the fender side of the vehicle body, only the fender side of the mountain portion of the bellows portion 10A is thick, ensuring pitting resistance, and other Since the mountain portion remains thin, the absorbent function of the bellows portion remains almost unchanged.

Next, FIG. 4 shows a second embodiment of the present invention.
The shape of the crest of A is an ellipse, and other molding methods are the same as those described in the first embodiment, so redundant explanation will be avoided.

In this example, it is clear from the previous description that the ellipse is thin in the long sleeve direction and thick in the short axis direction, forming the peaks of the bellows portion 10A.

According to this embodiment, even if there is a space constraint as a resin filler tube, the peak part in the long sleeve direction of the bellows part 10^ is formed thin, so it can be used without impairing the bellows function. be able to.

[Effects of the Invention] As is clear from the above explanation, according to the present invention, only the parts where strength is required can be made thicker while retaining the bellows function, so the amount of material used can be reduced, and the weight can be reduced. A resin filler tube that can be peeled can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of a resin filler tube to which the present invention is applied, Fig. 2 is a sectional view of the first embodiment of the present invention and a mold, and Fig. 3 is a cross-sectional view of the first embodiment of the present invention. 4 is a front view of the second embodiment of the present invention, FIG. 5 is a sectional view for explaining the parison stretching process, and FIG. 6 is a sectional view showing a conventional resin filler tube. be. 10... Resin filler tube, 10^... Bellows part, 10B... Circular tube part, 13... Mold, 14A, 14B... Cross-sectional wave-shaped part of the mold, 14A1
, 14BI... Valley of the mold, 14A2, 1482...
・Mountain part of mold. Figure 4 shows the front and concave rows of the second name of Nekomyo.

Claims (1)

[Claims] A cylindrical parison is placed between split molds having a wave-shaped cross section, and in a resin filler tube formed by a blow molding method and having a bellows part, forming a thick wall among the peaks of the bellows part. 1. A resin filler tube, characterized in that the depth of the trough of the corrugated cross-section of the mold corresponding to the part is formed shallower than other parts, and is formed by a blow molding method.