JP3327442B2 - Manufacturing method of fuel filler pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel filler pipe (hereinafter, referred to as "filler pipe") in which a metal retainer is attached to an opening at a tip end of a pipe body, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A fuel filler pipe is a conduit that forms a flow path from a fuel supply port to a fuel tank. The pipe body often has a bent shape in order to avoid interference with other in-vehicle equipment, and in order to facilitate mass production, it is common to manufacture the resin body by blow molding of a resin material or the like. . In addition, a tubular metal retainer is usually attached to the opening at the distal end of the pipe main body into which the refueling gun is inserted to prevent damage due to contact with the refueling gun. Various proposals have been made on the installation structure of such a metal retainer.

For example, Japanese Unexamined Utility Model Publication No. Hei 3-7589 proposes the one shown in FIG. The tip of the filler pipe P protrudes from the opening B1 of the body panel B, and the cylindrical metal retainer 2 is installed in the opening of the protruding tip of the filler pipe P. Here, metal retainer 2
Under the condition that the O-ring 4 is mounted on the lower surface of the opening edge flange 21, the metal resin retainer 2 is injection-molded with a connection resin layer 71 having a predetermined thickness on the upper half outer peripheral surface. Then, the end surface 71a of the connection resin layer 71 thus formed is welded and connected to the end surface 11a of the resin pipe main body 1, whereby the pipe main body 1
The metal retainer 2 is integrated with the conventional technology (prior art 1).

Further, Japanese Utility Model Laid-Open Publication No. 3-177398 discloses a filler pipe shown in FIG. In the installation structure of the metal retainer 2 disclosed in this publication, first, an O-ring 4 is inserted into a groove formed on the inner periphery of the distal end opening of the pipe body 1, and the lower half of the cylindrical metal retainer 2 is inserted from above. Is fitted. Thereafter, the connection resin layer 72 is injection-molded so as to cover the upper half outer periphery of the metal retainer 2 and the outer periphery of the distal end of the pipe main body 1 (prior art 2).

[0005]

However, these conventional filler pipes have the following problems. In the prior art 1, the connection resin layer 71 and the end faces of the pipe main body 1 are merely friction welded to each other, and it is not clear whether the end faces are completely welded and sealed, and there is a risk of poor sealing. In addition, there is a concern that the seal area is as small as only the end face, and the seal area comes off due to an external impact. On the other hand, if a filler pipe is to be manufactured according to the prior art 2, a housing groove for the O-ring 4 must be cut in the inner peripheral surface of the pipe body 1 in a separate step, and the pipe body 1 by blow molding also has an opening inside. Prior to fitting the metal retainer 2, the inner peripheral surface of the pipe body 1 had to be cut to a predetermined diameter before the metal retainer 2 was fitted. In addition, it is difficult to obtain dimensional accuracy by this cutting process, and even if the O-ring 4 is compressed and the outer periphery of the pipe body 1 to which the metal retainer 2 is attached is subjected to injection molding to improve the sealing property, Since the accuracy of the main body 1 is poor, satisfactory results in the sealing performance have not always been obtained.

[0006] The present invention solves the above-mentioned problems, and is a fuel filler pipe which has a reliable seal for a metal retainer mounting portion, and which is structurally robust and easy to manufacture.
And to provide a method of manufacturing.

[0007]

The gist of the first invention is to provide a method for manufacturing a fuel filler pipe in which a cylindrical metal retainer is mounted at an opening at the tip of a resin pipe body extending from a fuel tank. The resin layer for connection is injection-molded on the outer peripheral surface, and then the inner periphery of the tip opening of the parison is located outside the resin layer for connection, and the mold is closed from the outside of the parison. After welding the peripheral surface to the end surface and the outer peripheral surface of the connection resin layer so as to hold them, air is blown into the parison, and the pipe body is shaped into a predetermined shape by blow molding. A method for producing a fuel filler pipe.

According to a second aspect of the present invention, there is provided a method for manufacturing a fuel filler pipe in which a cylindrical metal retainer is attached to an end opening of a resin pipe main body extending from a fuel tank. peripheral layer and without this and with a predetermined gap and fitted to the cylindrical resin body connecting resin layer, then seal disposed between the end face of the outer circumferential layer and an opening edge flange of the metal retainer While holding the member under pressure, a resin material is injected into the gap to form an inner peripheral layer of the connection resin layer, and thereafter, the inner periphery of the tip opening of the parison is formed outside the connection resin layer. It is characterized in that the pipe body is blow molded after the mold is closed and the mold is closed. The method for producing a fuel filler pipe according to the third aspect of the present invention includes the step of forming an outwardly projecting locking projection on the outer peripheral surface of the connection resin layer of the first or second aspect of the invention , and closing the mold surface when the mold is closed. It is characterized in that the peripheral wall of the opening of the parison is pinched by the stop projection.

[0009]

The method for producing a fuel filler pipe of the present invention.
As described above, when the front opening edge of the pipe main body is welded and fixed to these end surfaces and the outer peripheral surface so as to hold the end surface of the connection resin layer and at least a part of the outer peripheral surface following the end surface, the pipe main body is connected to the pipe main body. The bonding with the resin layer is enhanced, and the sealing property at this portion is ensured. Also, when the pipe main body is joined to the connecting resin layer integrated with the metal retainer by blow molding, it takes time to cut the inner peripheral surface of the pipe main body to a predetermined diameter and fit the metal retainer. It becomes unnecessary. When sheet seal member is interposed pressure held between the opening edge flange end face and the metal retainer peripheral layer, the sealing member exerts a sealing function under clamping pressure state, and the connection resin layer and the metal retainer The sealing property between the two is further improved. To form a locking projection on the outer peripheral surface of the connecting resin layer, bonding strength of the pipe body further increases to hardening. According to the production method of the present invention, since a cutting step is not required, a robust fuel filler pipe having excellent sealing properties at a mounting portion of a metal retainer can be easily produced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. (1) Example 1 FIGS. 1 to 6 show a fuel filler pipe according to the present invention.
An example of a method for manufacturing the same will be described. FIG. 1 is a longitudinal sectional view of a metal retainer installation portion of the filler pipe, FIGS. 2 to 6 are sectional views of a main part of an injection molding die showing a manufacturing process of the filler pipe, and FIG.
8 is a perspective view of a main part of a blow molding die showing a manufacturing process of the filler pipe, and FIG. 8 is a cross-sectional view of a main part of the blow molding die in which a metal retainer and a connection resin layer are set in FIG. The filler pipe P includes a pipe body 1, a metal retainer 2, and an O-ring 4 serving as a seal member .

[0011] The filler pipe body 1 is a resin tubular body made by blow molding. The filler pipe body 1
A pipe with a socket at the lower end that connects to the fuel tank, extending upward while forming a bent gasoline flow path to avoid interference of blowers, side members, etc., and attached to the car body at the tip A fuel filler is provided.

The metal retainer 2 is a tubular body attached to the opening at the tip end of the pipe main body 1. The upper end of the metal retainer 2 is bent outwardly to form an opening edge flange 21. The metal retainer 2 is formed with a circular screw protrusion 22 that is bent inward and protrudes inward at an intermediate position on the inner circumference, and a cover (not shown) is screwed to the screw protrusion 22. In the metal retainer 2 of the present embodiment, the diameter of the lower end opening is reduced.

A connection resin layer 3 having a predetermined thickness is formed on the entire outer periphery of the metal retainer 2. The connection resin layer 3 includes an inner peripheral layer 32 directly joined to the entire outer peripheral surface of the metal retainer 2.
And an outer peripheral layer 31 that covers and joins the inner peripheral layer 32. Forming the connection resin layer 3 with the outer peripheral layer 31 and the inner peripheral layer 32 will be described later.
The outer peripheral layer 31 formed in advance is disposed on the outer peripheral surface of the metal retainer 2 while the O-ring 4 is kept in a pressed state by the subsequent molding of the inner peripheral layer 32 to secure the sealing property. This is because 3 can be covered and fixed. The outer peripheral layer 31
The upper end is bent inward so as to cover the inner peripheral layer 32, and the O-ring 4 is disposed between the upper end surface 31 a and the opening edge flange 21 of the metal retainer 2 in a pressed state. On the outer peripheral surface of the outer peripheral layer 31 near the lower end, a locking projection 311 having a triangular cross section and projecting outward over the entire circumference is formed (FIG. 1).

An opening edge 11 of the pipe main body 1 reaching from a fuel tank (not shown) holds the lower end surface 3a of the connecting resin layer 3 and the lower half of the outer peripheral surface 3b including the locking projection 311. The lower end surface 3a and the outer peripheral surface 3b
And fix it by welding. Here, the outer peripheral surface 11a of the opening edge of the pipe body 1 that is bulging out is configured to be a sealing surface that is in contact with the inner peripheral surface of the body panel opening B1 (see FIG. 11).

Next, a method of manufacturing the filler pipe P having the above configuration will be described. First, as shown in FIG. 2, the metal retainer 2 is fitted and held on the protruding portion 511 of the movable mold 51 of the injection mold. Then, the opening edge flange 21 of the metal retainer 2
The O-ring 4 is arranged so as to be in contact with the outer peripheral layer 31. Subsequently, an outer peripheral layer 31 previously formed into a cylindrical resin body is fitted around the outer periphery of the metal retainer 2. The end surface 31 a of the outer peripheral layer 31 is disposed so as to contact the O-ring 4. After securing such a state, the movable mold 51 is operated toward the fixed mold 52 (FIG. 3). Then, the end of the outer peripheral layer 31 hits the fixed mold 52 and pushes the entire O-ring 4 to the left in FIG. 3, thereby pressing the O-ring 4 interposed between the end face 31 a and the opening edge flange 21. . In this process, a closed cylindrical gap S is formed between the inner metal retainer 2 and the outer peripheral layer 31.

Thereafter, the slide mold 53 is advanced from the side of the outer peripheral layer 31 (FIG. 4), and is brought into close contact with the outer peripheral surface of the outer peripheral layer 31 to bring the mold into a closed state (FIG. 5). The slide mold 53 is
The engagement with the locking projections 311 of the outer peripheral layer 31 also serves to fix the position of the O-ring 4 in a state where the O-ring 4 is pressed as described above. Subsequently, through a sprue 521, a runner 522, and a gate 523 formed in the fixed mold 52 (FIG. 6), a molten resin material is injected into the gap S to form an inner peripheral layer having a predetermined thickness corresponding to the cylindrical gap S. 32 is injection molded. In this forming process, the inner peripheral layer 32, the metal retainer 2 and the outer peripheral layer 3
1 are integrated with each other. The O-ring 4 is held in a pressed state by the end face 31 a of the outer peripheral layer 31 fixed to the opening edge flange 21.

Thus, the O-ring 4 and the outer peripheral layer 3
1, a metal retainer 2 provided integrally with a connection resin layer 3 composed of an inner peripheral layer 32 is taken out of an injection mold, and then these integrated products are provided between a blow mold 61 and a mandrel 63 provided therebetween. (Fig. 7). FIG. 8 shows a state in which an integrated product of the metal retainer 2, the connection resin layer 3, and the O-ring 4 is set on the mandrel 63. The metal retainer 2 is fitted upside down on the protrusion 631 at the tip of the mandrel 63, and the lower end opening of the metal retainer 2 is inserted into an annular recess formed between the outer periphery of the mandrel 63 and the projection 632 for preventing burr adhesion. Position. On the other hand, the opening edge of the upper end of the metal retainer 2 is engaged with a protrusion 633 formed on the outer periphery of the distal end of the protrusion 631 to prevent the metal retainer 2 from coming off.
To be fixedly set.

Thereafter, the cylindrical parison 1 'in a semi-molten state is supplied from the die 64 located above the mandrel 63 (FIG. 7), and the tip of the cylindrical parison 1' is formed by the burr-adhesion preventing projection 632 as shown by the chain line in FIG. The parison 1 ′ is hung down to the outer position so that the inner periphery of the tip opening of the parison 1 ′ is disposed outside the connection resin layer 3. After securing such a state, the left and right dies 6
1, 62 are closed (chain line in FIG. 8).

As the mold is closed, the biting projections 611 and 621 protruding from the mold surface cut at a predetermined position with the wall at the lower end of the parison as a variros portion. At the same time, the peripheral surface of the tip opening of the parison 1 ′ is welded and fixed to the end surface 3 a of the connection resin layer 3 and the outer peripheral surface 3 b including the locking projection 311 by the mold surface. The distance between the outer peripheral surface 3b of the connection resin layer 3 and the mold surface in the mold closed state is set smaller than the thickness of the parison 1 ',
Further, by providing the locking projections 311, the parison 1 ′ is in a pinched state at this portion, and the retained heat of the parison is smoothly transmitted to the resin layer 3 and the locking projections 311.
The locking projection 311 is thermally melted, and the parison 1 ′ and the connection resin layer 3 are joined. In addition, since a so-called meat pocket is formed in the portion A in FIG. 8, the heat held by the parison 1 'in this portion is efficiently transmitted to the connection resin layer 3, and the parison 1'
Is securely welded and fixed to the connection resin layer 3. Here, in order to more effectively realize the welding and fixing of the parison to the connection resin layer 3, it is preferable that the resin materials of the parison 1 ', the outer peripheral layer 31, and the inner peripheral layer 32 are compatible with each other. It is even more preferred that they are homogeneous materials. Specifically, high density polyethylene (HDPE), polyamide (PA6) is used as the material of the parison 1 'and the outer peripheral layer 31.
Examples of the material of the inner peripheral layer 32 include low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyamide (PA6), and an adhesive resin.

After the mold is closed, air is supplied into the parison 1 'from an air blow hole 634 provided at the center of the mandrel 63. The parison 1 '
Is connected to the end face 3a of the connection resin layer 3 by the inner peripheral surface of the opening at the tip end.
And the outer peripheral surface 3b are welded and fixed to each other, and while these are held, they are shaped into a shape along the mold surface to form the pipe main body 1 (FIG. 1). Thereafter, the mold is opened and the mold is released, and the bite-cutting projection 61 is formed.
The fuel filler pipe P in which the metal retainer 2 is attached to the opening at the tip end of the pipe body 1 is obtained by removing the variros portion divided at 1,621.

In the fuel filler pipe P thus manufactured, first, the inner peripheral layer 32 is injection-molded under the condition that the O-ring 4 is held by the metal retainer 2 and the outer peripheral layer formed in advance. As a result, an integrated product of the metal retainer 2 and the connection resin layer 3 is produced, so that the O-ring 4 sufficiently exhibits a sealing function. That is, the O-ring 4
Is held between the outer peripheral layer end face 31a and the opening edge flange 21 in a state of being pressed, so that good fuel sealing properties can be obtained. After setting the mandrel 63 on the above-mentioned integrated product in which the entire outer peripheral surface of the metal retainer 2 is covered with the connecting resin layer 3, the parison 1 ′ is applied to the connecting resin layer 3 so as to hold the connecting resin layer 3. Pipe body 1 by blow molding while fixing by welding
Is formed, the pipe body 1 and the connection resin layer 3 (metal retainer 2) are surely integrated even if the molding accuracy of the inner periphery of the opening of the blow molding is poor. Further, in the blow molding, the pipe body 1 is connected to the connection resin layer 3 as described above.
, And the outer peripheral surface following the end surface of the fuel filler pipe P, the joint surface is wider than that of the prior art 1, and the fuel filler pipe P is robust. In particular, the locking projection 311 is provided, and the interval between the outer peripheral surface 3b of the connection resin layer 3 and the mold surface in the mold closed state is set smaller than the thickness of the parison 1 '. The parison 1 'is in a pinched state, effectively transmitting the heat of the parison itself to the connection resin layer 3 side, and both are integrated in a molten state. As a result, the robustness is further improved. As shown in the embodiment, when the resin material of the parison 1 'and the resin material of the connection resin layer 3 are made of mutually compatible ones, the integration is gained momentum, and a remarkable effect appears. Then, first, the sealing property is ensured in the process of injection-molding the inner peripheral layer, and then the parison 1 ′ is blow-molded.
Is welded and fixed to the connecting resin layer 3 to form the pipe main body 1, so that the manufacturing procedure is good, the process of joining the metal retainer 2 and the pipe main body 1 is simplified, and the fuel filler pipe P is mechanically processed by cutting or the like. , And can be easily manufactured.

(2) Embodiment 2 In this embodiment, the locking projections 311 of the connection resin layer 3 are formed as shown in FIG.
As shown in the figure, it is formed at the lower end of the outer peripheral layer 31. With such a configuration, since the locking projections 311 are close to the pockets (FIG. 8A) of the parison 1 'at the time of the pro-forming, the heat of the parison 1' is more efficiently transmitted, and the fusion of the two is promoted. You. Other configurations and effects are the same as those of the first embodiment.

(3) Embodiment 3 In this embodiment, as shown in FIG. 10, a plurality of locking projections 311 are formed. With such a configuration, the bonding strength between the pipe body and the connection resin layer 3 is further improved. Other configurations and effects are the same as those of the first embodiment.

In the present invention, the present invention is not limited to the above-described embodiment, but can be variously changed within the scope of the present invention depending on the purpose and application. The shape and material of the pipe body 1, metal retainer 2, connection resin layer 3, and O-ring 4 can be appropriately selected. In the above embodiment, the O-ring 4 is used as the sealing member, but other gaskets may be used.

[0025]

As described above, the fuel filler pipe of the present invention and the method of manufacturing the same respond to the strength of the metal retainer mounting portion and the reliability of the seal and have a structure that is easy to manufacture. It exerts excellent effects on quality improvement and productivity improvement.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a metal retainer installation portion of a fuel filler pipe according to a first embodiment.

FIG. 2 is a partial cross-sectional view of a main part of an injection mold showing a molding step of an inner peripheral layer of a connection resin layer.

FIG. 3 is a partial cross-sectional view of a main part of an injection mold showing a molding step of an inner peripheral layer of a connection resin layer.

FIG. 4 is a partial cross-sectional view of a main part of an injection mold showing a molding step of an inner peripheral layer of a connection resin layer.

FIG. 5 is a partial cross-sectional view of a main part of an injection mold showing a molding step of an inner peripheral layer of a connection resin layer.

FIG. 6 is a cross-sectional view of a main part of an injection molding die showing a step of forming an inner peripheral layer of a connection resin layer.

FIG. 7 is a perspective view of a main part of a blow molding die showing a manufacturing process of the pipe body.

FIG. 8 is a fragmentary cross-sectional view of a blow molding die showing a process of manufacturing the pipe body.

FIG. 9 is a longitudinal sectional view of a metal retainer installation portion of the fuel filler pipe according to the second embodiment.

FIG. 10 is a longitudinal sectional view of a metal retainer installation portion of a fuel filler pipe according to a third embodiment.

FIG. 11 is a longitudinal sectional view of a metal retainer installation portion of a fuel filler pipe according to Conventional Technique 1.

FIG. 12 is a longitudinal sectional view of a metal retainer installation portion of a fuel filler pipe according to Prior Art 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pipe main body 11 Front end opening edge 2 Metal retainer 21 Opening edge flange 3 Connection resin layer 3a End surface (lower end surface) 3b Outer peripheral surface 31 Outer peripheral layer 31a End surface (upper end surface) 311 Locking projection 32 Inner peripheral layer 4 O-ring (seal) 1) Parison P Fuel filler pipe S Gap

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-185491 (JP, A) JP-A-3-7589 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 9/12 B25B 27/14 B29C 49/08 B29D 23/00

Claims (3)

(57) [Claims] 1. A method for manufacturing a fuel filler pipe in which a cylindrical metal retainer is attached to an end opening of a resin pipe main body extending from a fuel tank, wherein a connection resin layer is injection-molded on an outer peripheral surface of the metal retainer. Then, the inner periphery of the tip opening of the parison is located outside the resin layer for connection, and the mold is closed from the outside of the parison. A method for producing a fuel filler pipe, characterized in that, after being welded to a surface and holding them, air is blown into the parison and the pipe body is shaped into a predetermined shape by blow molding. 2. A method for manufacturing a fuel filler pipe in which a cylindrical metal retainer is attached to an opening at a distal end of a resin pipe main body extending from a fuel tank. Fit your body
Peripheral layer and without the connection resin layer Te, then while the sealing member is disposed between the end face and the opening edge flange of the metal retainer of the outer circumferential layer and clamp holding the resin material into the gap Injecting to form the inner peripheral layer of the connection resin layer, and thereafter, after positioning the inner periphery of the tip opening of the parison outside the connection resin layer, closing the mold, and then blow molding the pipe body. A method for producing a fuel filler pipe. 3. A locking projection protruding outwardly is formed on an outer peripheral surface of the connection resin layer, and when the mold is closed, the peripheral surface of the parison tip opening is pressed between the mold surface and the locking projection. The method for producing a fuel filler pipe according to claim 1 or 2 .