JPH069855Y2 - Mold for blow molding of resin filler tubes for automobile fuel tanks - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a blow molding die for a resin filler tube of an automobile fuel tank.

<< Prior Art >> As shown in FIG. 3, a fuel tank may be constructed by attaching a resin filler tube 3 having a bellows 2 to a tank body 1 made of metal or resin. The bellows 2 is for absorbing a positional deviation between the fuel filler port 4 and the mounting portion 5 at the time of collision of the automobile.

Such a filler tube 3 is generally made of polyethylene resin by blow molding.

When the filler tube has an S-shape as shown in the drawing, as shown in FIG. 4, the molds 6 and 7 are formed so that the entire tube is oriented substantially in the vertical direction. Bolster 8, 9
When the dies 6 and 7 supported by are opened and the parison, which is a molten resin hollow body, descends from above and is located between the dies 6 and 7, both dies 6 and 7 are closed and the pipe 10 below the pipe 10 is closed. Compressed air is blown in, the molten resin hollow body is pressed against the mold surfaces of both molds 6 and 7, and the filler tube 3 is molded.

<Problems to be solved by the device> In the case of a filler tube having a bellows 2 in the middle portion, which is bent in an S-shape in this way, the entire tube is placed in a vertical direction because the parison comes down from above. The mold is formed so as to face. In this case, as shown in FIG. 5, the axis A of the tube portion having the bellows 2 is inclined with respect to the direction C perpendicular to the mold opening direction B. The bellows 2 is formed by connecting a plurality of peaks in the axial direction on the same axis D as the axis A, and each peak is formed around a plane E perpendicular to the axis D. Therefore, an undercut portion F that enters inside the opening direction B of the molds 6 and 7 is generated in a part of each mountain, and the undercut portion F is scraped when the molds 6 and 7 are opened. There was a problem that the molded product was scratched and the strength was reduced. The undercut portion F becomes larger as the slope of the mountain of the bellows 2 becomes steeper.

Therefore, the purpose of this invention is to prevent the bellows part from being scratched by a resin filler tube in which the axis of the tube part having the bellows is inclined with respect to the direction perpendicular to the mold opening direction of the blow molding die. It is an object of the present invention to provide a blow molding die for a resin filler tube of an automobile fuel tank for blow molding.

<< Means for Solving Problems >> A blow molding mold for a resin filler tube of an automobile fuel tank according to the present invention is a blow molding mold for molding a filler tube having a tube portion having a bellows by blow molding. A mold, wherein the mold comprises a pair of split molds each having a mold surface shape obtained by dividing the filler tube in two in the axial direction, and the filler tube in the mold surface shape of both split molds. The portion forming the bellows portion was configured as a surface shape parallel to the mold opening direction of both split molds.

<Operation> As the inclination of the axis of the bellows itself becomes closer to the direction perpendicular to the mold opening direction, the number of undercuts decreases, and the molded product is prevented from being scratched.

<Embodiment> FIG. 1 shows an example of a blow molding die for molding a filler tube according to the present invention, which differs from the conventional example only in the structure of the bellows portion of the filler tube, and therefore the same member is used. Will be described using the same symbols.

The filler tube 3 is formed in an S shape and has a bellows 2 in the middle thereof. The molds 6 and 7 have a mold surface shape in which a filler tube 3 oriented in the vertical direction is divided into two along the axis thereof. Molds 6 and 7 are supported by bolsters 8 and 9,
The mold is opened and closed by a hydraulic mechanism.

When the molds 6 and 7 are opened and the parison is lowered from above and positioned between the molds 6 and 7, both molds 6 and 7 are closed and compressed air is blown from the pipe 10 below, so that the parison is separated. The filler tube 3 is formed by being pressed against the mold surfaces of the molds 6 and 7.

As shown in FIG. 2, the bellows 2 of the filler tube 3 is
It is formed by making the inclination of its own axis D closer to the direction C perpendicular to the mold opening direction B of the molds 6 and 7 with respect to the axis A of the tube portion having the bellows. Each peak of the bellows 2 is formed around a plane E perpendicular to the axis D, and the appearance is an ellipse because the axis D of the bellows is inclined with respect to the axis A of the tube portion, but this is a perfect circle. You may form so that it may become.

In this way, the inclination of the axis D of the bellows itself is brought closer to the direction C which is perpendicular to the mold opening direction B with respect to the axis A of the tube portion. No more scratches on the bellows 2 during mold opening.

The minimum inclination of the axis D with respect to the axis A depends on the inclination of the crest of the bellows 2, but the undercut portion does not occur in the crest of the bellows, or even if it occurs, it is possible to force removal and ignore the scratches during forceful removal. It is set to the extent possible.

The maximum inclination of the axis D with respect to the axis A coincides with the direction C perpendicular to the mold opening direction B, and the peaks of the bellows 2 at this time coincide with the horizontal direction, that is, the mold opening direction B.

In this case, no matter how steep the mountain is, no undercut occurs.

<Effects of the Invention> As described above, the blow molding die for the resin filler tube of the fuel tank for automobiles according to the present invention is a blow molding mold for molding a filler tube having a tube portion having a bellows by blow molding. A mold, wherein the mold comprises a pair of split molds each having a mold surface shape obtained by dividing the filler tube in two in the axial direction, and the filler tube in the mold surface shape of both split molds. Since the part that forms the bellows part is configured as a surface shape that is parallel to the mold opening direction of both split molds, the undercut part is less in the bellows, and the bellows are scratched during mold opening and the strength is reduced. Can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a filler tube molding die showing an embodiment of the invention, FIG. 2 is a partially enlarged sectional view of the molding die in an open state, and FIG. 3 is related to the invention. 4 is a schematic front view of a fuel tank equipped with a resin filler tube, FIG.
FIG. 5 is a cross-sectional view of the same filler mold, and FIG. 5 is a partially enlarged cross-sectional view of the mold with the mold open. 1 ... Tank main body, 2 ... Bellows, 3 ... Filler tube, 6,7 ... Mold, A ... Shaft part of the tube part, B ... Mold opening direction, C ... Mold opening direction Vertical direction, D …… axis of the bellows itself, E …… center plane of each mountain of the bellows,
F: Undercut part.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area B29L 23:22 4F

Claims (1)

[Scope of utility model registration request] 1. A blow molding mold for molding a filler tube having a tube portion having a bellows by blow molding, wherein the mold is a mold surface shape obtained by dividing the filler tube into two in the axial direction. A pair of split molds having a shape, the portion forming the bellows part of the filler tube in the mold surface shape of both split molds, the surface shape parallel to the mold opening direction of both split molds. A mold for blow molding of resin filler tubes for automobile fuel tanks.