JP2847582B2 - Production equipment for resin fuel tanks - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a resin fuel tank having a baffle plate for improving rigidity and restricting fuel oscillation.

[0002]

2. Description of the Related Art Conventionally, as this kind of synthetic resin fuel tank, as shown in FIG. 7, a rectangular parallelepiped resin tank 1 formed by blow molding and a synthetic resin baffle plate 2 disposed in this tank 1 are shown. The baffle plate 2 is vertically welded and fixed by a fixing portion 3 having a concave longitudinal section and protruding inward from a position where the upper surface and the lower surface of the tank 1 face each other.

As shown in FIG. 8, a pair of molds 4 forming a rectangular parallelepiped cavity has a projection 5 at the center of the inner surface thereof, and the baffle plate 2 It is supported in a horizontal state at the tip of a pipe-shaped blow pin 6 for blowing air, and both ends thereof are arranged so as to face the projections 5 of the two dies 4 respectively. And the thermoplastic resin parison 7 which is the material of the tank 1
Draw-down between a pair of heated and released molds 4 and fitted to the baffle plate 2. Next, as shown in FIG. Then, the opposite side walls of the parison 7 are pressed by the projections 5 to weld both ends of the baffle plate 2 to the opposite side walls of the parison 7. Thereafter, as shown in FIG. 10, the tip of the blow pin 6 is separated from the baffle plate 2, and compressed air is blown into the inside of the parison 7 from the tip of the blow pin 6 so that the parison 7 comes into close contact with the inner surfaces of both the molds 4. The hollow body 8 is molded by being expanded.

Next, after the hollow body 8 is cooled, as shown in FIG. 11, the blow pins 6 are pulled out from the mold 4 and then both the molds 4 are released, and the molded hollow body 8 is released. At the same time, the pinch-offs 9 and 10 formed at the upper and lower ends of the hollow body 8 are cut to obtain the tank 1 as shown in FIG. Since the opening 10a has a cylindrical shape for the blow pin 6, a grommet 11 is welded and closed here, and a hole 12 for an air breather is formed on the other side of the tank 1 to obtain a finished product.

FIG. 12 and FIG. 1 show another conventional example.
As shown in FIG. 3, a pair of blow-molding dies 13 having baffle plate-forming projections 14 protruding from each other at opposing positions on the inner surface are used. After the opposite wall is pressed and welded and connected by the projections 14, it is expanded by blow molding so as to be in close contact with the inner surface of the mold 13, and a hollow baffle plate 17 is integrally formed in a plastic tank 16. (Japanese Utility Model Application Laid-Open No. 56-171337).

As another conventional example, as shown in FIG. 14, pipe-shaped baffle plate forming slide cores 19 are respectively penetrated by a pair of mold members 18 by a reciprocating drive means 20 so as to be able to advance and retreat. There is a manufacturing apparatus having a structure in which a suction means 21 is connected to the slide core 19, and at the time of molding, a pair of slide cores 19 are moved forward to press the opposing walls of the parison 22 to be welded and connected. Is retracted, and the air in the mold member 18 is sucked through the slide core 19 by the suction means 21 to bring the parison 22 into close contact with the inner surface thereof, and the hollow baffle plate 24 is placed in the fuel tank 23 in the same manner as in the conventional example. It is molded integrally (Japanese Utility Model Laid-Open No. 63-119024).

[0007]

However, in the conventional example shown in FIGS. 7 to 11, the projection 5 of the mold 4 for welding the baffle plate 2 to the parison 7 is fixed. It is impossible to control the applied pressure of the baffle plate 2 and the tank body 1 when the applied pressure is too low. On the contrary, when the applied pressure is too high, the impact strength of the welded portion is reduced. There is a disadvantage that it becomes easier. Since the pinch-off 10 at the lower end of the tank body 1 is not completely closed and is opened in a cylindrical shape for the blow pin 6, a grommet 11 and a welding step for the grommet 11 are required. In this case, a hole 12 for the air breather must be formed, which increases the cycle time of the manufacturing process and increases the cost. Further, since the grommet welding portion is formed on the side surface of the tank body 1 which is always in contact with fuel, there is a possibility that the strength may be reduced.

In the conventional examples shown in FIGS. 12 to 14, both the baffle plates 17 and 24 are formed integrally with the parisons 15 and 22 by suddenly changing the shape in the direction perpendicular thereto. There is a possibility that the thickness may vary and the thickness may become uneven at the stress concentration portion A and the thickness may become the largest at the portion B which does not require the wall pressure. For this reason, in order to ensure the strength of the product, it is necessary to make the whole thick and heavy especially in order to secure the thickness of the stress concentration portion A.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and does not require a hole filling step for a blow pin and a hole forming step for an air breather. The purpose of the present invention is to provide a device that can arbitrarily adjust the pressing force of the parison to the baffle plate to make the wall thickness distribution more uniform. A mold, a support rod that can extend and retract to support a baffle plate mounted in the parison, and a pair of pressing portions slidably disposed on the mold to weld the baffle plate to the parison. And a blow pin that also serves as a hole for an air breather that penetrates the mold.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS. 1 to 5 are molding process diagrams of a resin fuel tank by the manufacturing apparatus according to the present invention,
FIG. 6 is a perspective view of a resin fuel tank molded by the same process.

In FIG. 1, reference numeral 30 denotes a pair of molds forming a rectangular parallelepiped cavity. At the center of the inner surface of the mold, a pressing portion 31 is slidably movable with respect to the mold by driving means 32 such as a cylinder. Is provided.

Reference numeral 33 denotes a parison of a thermoplastic resin used as a material of the tank body 34 (see FIG. 6), which is heated to a predetermined temperature and extruded from an extruder. 35 is the tank body 3
The resin rectangular baffle plate built in 4
The baffle plate 35 is horizontally supported by the tip of a support bar 36 having no blow pin function (that is, not having a cylindrical shape), and both ends thereof are arranged so as to face the pressing portions 31 of the two dies 30 respectively. ing.

A blow pin 37 is disposed in one of the molds 30 so as to penetrate therethrough. The blow pin 37 is of a type that blows air by blowing means 38 of a cylinder. It has the same outer diameter as the hole 39 for the air breather to be formed.

Then, as shown in FIG. 2, after the parison 33 is drawn down between the molds 30 in the released state and fitted on the baffle plate 35, the pressing unit 31 is first advanced by the driving means 32. The opposing side wall of the parison 33 is pressed, and the end of the baffle plate 35 is
3 is welded and fixed to the inner surface. At this time, the pressing force of the pressing portion 31 can be arbitrarily adjusted by the driving means 32.
Then, after the welding is completed, the support bar 36 is removed from the mold 30.

Then, as shown in FIG. 3, the upper and lower ends of the parison 33 are sealed by clamping the two molds 30. At this time, the tip of the blow pin 37 penetrates through the side wall of the parison 33 and protrudes into the inside. I do. Then, as shown in FIG. 4, compressed air is blown into the inside of the parison 33 from the tip of the blow pin 37 to expand so as to be in close contact with the inner surface of the mold 30, and the hollow body 40 is molded.

After cooling the hollow body 40, as shown in FIG. 5, both the molds 30 are released together with the pressing portion 31, and the hollow body 40 is released and taken out. Then, the pinch-offs 41 and 42 formed at the upper and lower ends of the hollow body 40 are cut,
Thus, a resin tank main body 34 as shown in FIG. 11 is obtained. In the above embodiment, the number of the baffle plates 35 is one, but the same applies to two or more baffle plates.

As described above, since the pinch-offs 41 and 42 of the tank body 34 are completely sealed, there is no need to close the grommet by welding, and the opening of the blow pin 37 becomes a hole 39 for the air breather. There is no need to drill holes in post-processing.

[0018]

As described above, the resin fuel tank manufacturing apparatus according to the present invention has a pair of dies for blow-molding a parison and a retractable support for supporting a baffle plate mounted in the parison. It comprises a support rod, a pair of pressing portions slidably disposed on the mold for welding the baffle plate to the parison, and a blow pin that also serves as a hole for an air breather penetrating the mold. Therefore, it is possible to uniformly form the thickness distribution of the tank body by arbitrarily adjusting the pressing force of the pressing portion at the welding portion between the parison and the baffle plate, and to obtain a lighter and more stable one having the same strength. Strong products can be obtained. In addition, since the blow pin doubles as a hole for the air breather, drilling is completed at the same time as air blowing, so that post-processing drilling can be omitted. Since it is sealed, the conventional grommet and grommet welding process are not required, and the strength can be improved by forming ribs and beads on the baffle plate itself. There are various effects that can be done.

[Brief description of the drawings]

FIG. 1 is a first view of a fuel tank by a manufacturing apparatus according to the present invention.
It is a molding process diagram.

FIG. 2 is a second molding step diagram.

FIG. 3 is a third molding step diagram.

FIG. 4 is a fourth molding step diagram.

FIG. 5 is a fifth molding step diagram.

FIG. 6 is a perspective view of a resin fuel tank molded by the same device.

FIG. 7 is a perspective view of a conventional fuel tank.

FIG. 8 is a first molding step diagram of the fuel tank manufacturing apparatus.

FIG. 9 is a second molding step diagram of the fuel tank manufacturing apparatus.

FIG. 10 is a third molding step diagram of the fuel tank manufacturing apparatus.

FIG. 11 is a fourth molding step diagram of the fuel tank manufacturing apparatus.

FIG. 12 is a longitudinal sectional view of another conventional fuel tank molding die.

FIG. 13 is a sectional view of a fuel tank molded by the molding die.

FIG. 14 is a schematic diagram of a molding process of a conventional fuel tank manufacturing apparatus.

[Explanation of symbols]

 Reference Signs List 30 mold 31 pressing part 32 driving means 33 parison 34 tank body 35 baffle plate 36 support rod 37 blow pin 39 air breather hole 40 hollow body 41 pinch off 42 pinch off

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI // B29L 24:00 (56) References JP-A-56-28831 (JP, A) JP-A-1-294439 (JP, A) JP JP-A-1-301227 (JP, A) JP-A-4-212828 (JP, A) JP-A-5-3055651 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 49 / 00-49/80

Claims (1)

(57) [Claims] 1. A pair of molds for blow-molding a parison, a support rod which can be protruded and retracted for supporting a baffle plate mounted in the parison, and a mold for welding the baffle plate to the parison. An apparatus for manufacturing a resin fuel tank, comprising: a pair of pressing portions slidably disposed; and a blow pin which also serves as a hole for an air breather penetrating the mold.