JP2008168766A - Nipple fixing structure for fuel tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nipple fixing structure for a fuel tank of an automobile having extremely low fuel permeability from a nipple and a nipple fixing part and excellent sealability. <P>SOLUTION: A fuel tank 1 is formed by welding an upper shell 10 and a lower shell 20 composed of inner resin layers 15, 25 and outer sheet layers 16, 26, respectively. A nipple fixing part 13 has a cylindrical part 13a and a bottom wall 13b, and the outer surface side of the fuel tank is covered with the outer seat layers. A nipple 30 has a cylindrical part 31, a groove 35, and a seal member 34 fixed to the outer circumference of a lower cylindrical part of a flange. In the nipple fixing structure of the fuel tank, the nipple is inserted in the nipple fixing part and a support ring 60, the seal member 34 is abutted on the outer sheet layer 16 of the nipple fixing part 13, and a locking claw 63 of the support ring 60 is fitted to the groove 35 of the nipple 30 to lock the nipple. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a nipple mounting structure for mounting a nipple that forms an inlet / outlet for fuel or the like of a fuel tank for an automobile to the fuel tank.

As a structure of a fuel tank for automobiles, a plurality of nipples for attaching a tube for injecting fuel into the fuel tank or transporting fuel from the fuel tank to the engine side are attached to the wall of the fuel tank.
Conventionally, such fuel tanks have been made of metal, but in recent years, they have been made of thermoplastic resin due to the weight reduction of vehicles, the absence of rust, and the ease of molding into a desired shape. It has come to be used.

Conventionally, this thermoplastic resin fuel tank is often formed by blow molding. However, in order to attach a nipple, a separately formed nipple may be fused to the fuel tank. In this case, since the fuel tank is pierced and the nipple is heat-sealed, the number of work steps is great.
Further, when fitting the nipple to the fuel tank, it is necessary to form a cylindrical mounting portion for mounting the nipple on the fuel tank by blow molding in advance. And the cylindrical nipple which has a flange part on the outer periphery was formed by injection molding etc., and the nipple was inserted in the attachment part.

However, in this case, since the nipple is strongly pressed into the cylindrical mounting portion, an excessive force is applied to the mounting portion, and the press-fitting work is difficult. Further, there is a risk that the fuel hits the mounting part due to the swelling of the fuel, or the sealing performance decreases due to the expansion. Furthermore, the residual stress at the time of inserting the nipple remains in the mounting portion, and after a long time, there is a possibility that the sealing performance may be deteriorated due to a change with time.
In addition, since the fuel tank is easy to make a hollow shape, it is often molded by blow molding. In the case of blow molding, the dimensional accuracy is lower than that of injection molding, so the mounting portion is improved by post-processing. There was a need.

Therefore, in recent years, the synthetic resin fuel tank is divided into upper and lower parts, and the upper shell part and the lower shell part are separately molded by injection molding or the like, and then the joint peripheral edge parts of the upper shell part and the lower shell part are melted together. A method of forming a fuel tank by wearing is also performed (see, for example, Patent Document 1). In this case, it is also easy to form a nipple mounting portion for attaching a nipple to the upper shell portion and the lower shell portion, and accessories such as a fuel pump can be easily installed inside the fuel tank before the upper shell portion and the lower shell portion are fused. It can also be attached to. Further, ribs or beams for reinforcement or mounting can be easily formed on the inner surfaces of the upper shell portion and the lower shell portion.

In such a fuel tank 101 in which the upper shell portion and the lower shell portion are injection-molded, for example, as shown in FIG. 11, the nipple mounting portion 113 is formed integrally with the fuel tank 101. And it forms in the nipple attaching part 113 so that it may have the bottom wall part 113b in the front-end | tip of the cylindrical part 113a and the cylindrical part 113a. The nipple 130 is formed with a cylindrical portion 131, a flange portion 132 on the outer periphery of the cylindrical portion 131, a slit 137 and a protruding portion 135 near the tip, and a seal ring 134 is attached between the flange portion 132 and the protruding portion 135. .

When the slit 137 of the nipple 130 is bent and inserted into the nipple mounting portion 113, the projection 135 of the nipple 130 is locked to the bottom wall portion 113b of the nipple mounting portion 113, and the flange portion 132 is connected to the nipple mounting portion 113. 113, the nipple 130 is fixed, and the seal ring 134 seals between the nipple 130 and the nipple mounting portion 113 (see, for example, Patent Document 2).

However, in this case, the material constituting the fuel tank 101 is deformed over time, expands due to fuel swelling, the material physical properties are deteriorated, and the engagement strength of the nipple mounting portion 113 is lowered. As a result, there was a risk that the sealing performance would drop and the nipple would fall off when an external force was applied. Further, when the diameter of the cylindrical portion 113a of the nipple 130 is small, it is difficult to provide the slit 137 in the cylindrical portion 113a, and it is difficult to sufficiently secure the engagement strength between the nipple 130 and the nipple mounting portion 113.

In recent years, from the viewpoint of protecting the global environment, it has been required to extremely reduce the fuel permeation from the fuel tank 1. For this reason, some fuel tanks that fuse the upper shell portion and the lower shell portion are formed with a three-layer structure including a barrier layer in the middle in order to prevent fuel permeation from within the fuel tank (for example, Patent Documents). 3).
In such a case, it was necessary to reliably prevent fuel permeation at the nipple mounting portion.

JP-A-11-34180 JP 2005-29100 A Japanese Patent Application Laid-Open No. H5-16938

  Accordingly, the present invention provides a nipple mounting structure for an automobile fuel tank that is easy to mold a nipple mounting portion of a fuel tank, has a very low fuel permeability from the nipple and the nipple mounting portion, and is excellent in sealing performance. Is.

In order to solve the above problems, the present invention of claim 1 is a fuel tank nipple mounting structure for mounting a nipple forming a liquid or gas inlet / outlet of a thermoplastic synthetic resin fuel tank.
The fuel tank is integrally formed by fusing the joint peripheral parts of the upper shell part and the lower shell part, which are separately molded by injection molding, respectively, and the upper shell part and the lower shell part are respectively an inner resin layer and The outer sheet layer covering the outer surface of the inner resin layer,
The nipple mounting structure has a nipple mounting portion formed on a part of the outer wall of the upper shell portion or the lower shell portion, a nipple mounted on the nipple mounting portion, and a support ring for locking the nipple.
The nipple mounting portion has a cylindrical portion that bulges toward the inside of the fuel tank, and extends from the inner surface of the cylindrical portion toward the center of the cylinder at a substantially right angle from the inner surface of the cylindrical portion. A bottom wall portion having a hole to be inserted is provided, and the outer surface side of the fuel tank of the cylindrical portion and the bottom wall portion is covered with an outer sheet layer,
The nipple is inserted into the nipple mounting portion to allow a liquid or gas to flow therethrough, a flange portion that is formed on the outer periphery of the cylindrical portion and contacts the outer surface side of the fuel tank around the nipple mounting portion, and the nipple is a nipple. A groove portion formed on the outer periphery of the cylindrical portion at a position inside the fuel tank relative to the bottom wall portion when inserted into the mounting portion, and a seal member attached to the outer periphery of the cylindrical portion below the flange portion are provided. And
The support ring has a locking claw,
The nipple of the fuel tank in which the nipple is inserted into the nipple mounting portion and the support ring, the seal member comes into contact with the outer sheet layer of the nipple mounting portion, and the locking claw of the support ring fits into the groove portion of the nipple to lock the nipple. It is a mounting structure.

In the first aspect of the present invention, the fuel tank is integrally configured by fusing the joint peripheral portions of the upper shell portion and the lower shell portion that are separately molded by injection molding. For this reason, the fuel tank formed by combining the upper shell portion and the lower shell portion can obtain a precise and high strength product with high dimensional accuracy. Also, component mounting ribs and reinforcing ribs can be formed inside the upper shell portion and the lower shell portion, so that built-in components and the like can be easily attached and the strength of the fuel tank can be improved.

Since the joint peripheral portions of the molded upper shell portion and lower shell portion are fused, the joint peripheral portions of the upper shell portion and the lower shell portion are firmly and integrally joined, and the upper shell portion and the lower shell are combined. Since the strength of the joining portion of the part is increased and an adhesive or the like for joining is unnecessary, manufacturing is easy. Moreover, the sealing property of a joining peripheral part can also be ensured.

The upper shell portion and the lower shell portion are each composed of an inner resin layer and an outer sheet layer covering the outer surface of the inner resin layer. Therefore, a resin having high strength and excellent moldability can be selected for the inner resin layer, and a sheet having excellent fuel permeation resistance can be used for the outer sheet layer, which is easy to manufacture.
Further, the outer sheet layer does not extend or break due to the molding of the inner resin layer, and excellent fuel permeation resistance can be obtained.

The nipple mounting structure includes a nipple mounting portion formed on a part of the outer wall of the upper shell portion or the lower shell portion, a nipple mounted on the nipple mounting portion, and a support ring for locking the nipple. Therefore, the nipple can be easily attached to the outer wall of the fuel tank, and the nipple can be locked by the support ring so as not to be detached from the nipple attachment portion.

The nipple mounting portion has a cylindrical portion that bulges toward the inside of the fuel tank, and extends from the inner surface of the cylindrical portion toward the center of the cylinder at a substantially right angle from the inner surface of the cylindrical portion. A bottom wall having a hole for insertion is provided. Therefore, the cylindrical portion of the nipple and the seal member can be held by the cylindrical portion, and the nipple mounting portion does not protrude from the outer surface of the fuel tank, so that the safety is high and the appearance is good. Further, the cylindrical portion of the nipple and the support ring can be held by the bottom wall portion.
Moreover, since the outer surface side of the fuel tank in the cylindrical portion and the bottom wall portion is covered with the outer sheet layer, it is possible to prevent the fuel from permeating from the nipple mounting portion.

Since the nipple has a cylindrical portion that is inserted into the nipple mounting portion and allows the liquid or gas to flow therethrough, the hose or the like is connected to the nipple and the liquid or gas can be taken into and out of the fuel tank through the cylindrical portion.
Since it has a flange part that is formed on the outer periphery of the cylindrical part and comes into contact with the outer surface of the fuel tank around the nipple mounting part, when the nipple is inserted into the nipple mounting part, the flange part is located at or around the nipple. The flange portion can abut and position the nipple.

When the nipple is inserted into the nipple mounting portion, it has a groove formed on the outer periphery of the cylindrical portion at a position inside the fuel tank relative to the bottom wall portion. Can be fixed.
Since the seal member is attached to the outer periphery of the cylindrical portion at the lower portion of the flange portion, when the nipple is inserted into the nipple attachment portion, the seal member abuts on the outer sheet layer of the nipple attachment portion to perform sealing. It is possible to prevent permeation of fuel from between the nipple mounting portion and the nipple.

Since the support ring has a locking claw, when the nipple is inserted into the nipple mounting portion, the locking claw is locked in the groove portion of the nipple and the nipple can be fixed.
The nipple is inserted into the nipple mounting portion and the support ring, the seal member abuts on the outer sheet layer of the nipple mounting portion, and the locking claw of the support ring fits into the groove portion of the nipple to lock the nipple. By inserting the nipple into the nipple attachment portion, the nipple is firmly fixed to the nipple attachment portion, and fuel can be prevented from passing through between the nipple attachment portion and the nipple.

According to the second aspect of the present invention, the support ring includes a side wall portion formed in a cylindrical shape, and a hole that extends from the tip of the side wall portion in a direction perpendicular to the center of the side wall portion and into which the cylindrical portion of the nipple is inserted. A support claw formed at the tip of the bottom part, and the side wall part of the support ring is inserted into the outer periphery of the cylindrical part of the nipple attachment part, and the bottom part is the bottom wall part of the nipple attachment part The fuel tank nipple mounting structure holds the surface inside the fuel tank, and the locking claw fits into the groove portion of the nipple to lock the nipple.

In the second aspect of the present invention, the support ring has a side wall portion formed in a cylindrical shape, and the side wall portion of the support ring is fitted into the outer periphery of the cylindrical portion of the nipple mounting portion. Therefore, the side wall of the support ring can be fitted to the cylindrical portion of the nipple mounting portion to prevent the cylindrical portion of the nipple mounting portion from being expanded or deformed, and the strength of the nipple mounting portion can be maintained and the seal can be maintained. Property can be secured stably for a long period of time.

It has a bottom part extending from the front end of the side wall part in a direction perpendicular to the center of the side wall part and having a hole into which the cylindrical part of the nipple is inserted at the center. Hold the face. Therefore, deformation of the bottom wall portion can be prevented, and the support ring can be prevented from moving to the outside of the fuel tank, thereby preventing the nipple from coming off.
There is a locking claw formed at the tip of the bottom side, and when the nipple is inserted into the support ring, the locking claw fits into the groove of the nipple and locks the nipple. Can be prevented from moving to.

  The third aspect of the present invention is the fuel tank nipple mounting structure in which the outer sheet layer is a fuel permeation-resistant multilayer resin sheet.

In the third aspect of the present invention, since the outer sheet layer is a fuel-permeable multi-layer resin sheet, it is possible to prevent permeation of the fuel oil inside the fuel tank. Because it is a multilayer sheet, a layer with good adhesion to the inner resin layer is formed on the surface facing the inner resin layer of the upper shell portion and the lower shell portion of the fuel permeation resistant layer in the multilayer sheet, and wear resistance on the outside And impact resistant layers can be formed. Further, the strength of the fuel tank can be increased.

  According to a fourth aspect of the present invention, there is provided a nipple mounting structure for a fuel tank in which a step portion protruding from the cylindrical portion is formed on the lower surface of the flange portion of the nipple, and the sealing member is held by the nipple mounting portion at the step portion.

In the fourth aspect of the present invention, the step portion protruding from the cylindrical portion is formed on the lower surface of the flange portion of the nipple, and the seal member is held by the cylindrical portion of the nipple attachment portion at the step portion. It can hold | maintain inside a cylindrical part, can contact | abut a sealing member and an outer sheet | seat layer reliably, and can ensure the sealing performance between a nipple attachment part and a nipple.

  According to a fifth aspect of the present invention, the nipple is a fuel that is at least one of an inlet lower that injects fuel into the fuel tank, a breather port through which gas inside the fuel tank enters and exits, and a fuel main port that discharges fuel inside the fuel tank. This is a tank nipple mounting structure.

In the present invention of claim 5, the nipple is at least one of an inlet lower for injecting fuel into the fuel tank, a breather port through which gas inside the fuel tank enters and exits, and a fuel main port through which fuel inside the fuel tank is discharged. For this reason, it is possible to reliably ensure sealing performance at each of the injection and discharge of fuel into the fuel tank and the discharge portion of the fuel oil vapor inside the fuel tank.

According to the present invention of claim 6, in the upper shell portion and the lower shell portion, the inner resin layer is formed of high-density polyethylene (HDPE), the outer sheet layer is formed of a fuel-permeable multilayer resin sheet, and the fuel-permeable multilayer The layer in contact with the inner resin layer of the resin sheet is a fuel tank formed of a material compatible with high density polyethylene (HDPE).

In the present invention of claim 6, since the inner resin layers of the upper shell portion and the lower shell portion are formed of high density polyethylene (HDPE), the molding is easy in the injection molding and the strength of the hollow resin molded product is increased. can do.
The outer sheet layer is formed of a fuel-resistant multilayer resin sheet, and the layer in contact with the inner resin layer of the fuel-permeable multilayer resin sheet is formed of a material compatible with high-density polyethylene (HDPE). When fuel oil is put inside the hollow resin molded product, permeation of the fuel oil can be prevented. Because it is a multilayer sheet, high-density polyethylene (HDPE) and a layer with good adhesion are formed on the surface of the fuel-permeable layer opposite to the upper shell portion and the inner resin layer of the lower shell portion, and the outer surface has high wear resistance and An impact resistant layer can be formed. The fuel permeation-resistant multilayer resin sheet covers up to the front end of the flange portion of the fusion part of the inner resin layer, and the fuel permeation-resistant layers of the respective fuel permeation-resistant multilayer resin sheets are close to each other at the front end of the flange portion. Can be fused. For this reason, it can prevent that a fuel permeate | transmits from the front-end | tip of the flange part of the fusion | melting part of an upper shell part and a lower shell part.

  Since the nipple is inserted into the nipple mounting portion and the support ring, the seal member abuts the outer sheet layer of the nipple mounting portion, and the locking claw of the support ring fits into the groove portion of the nipple to lock the nipple. It is firmly fixed to the nipple mounting portion and can secure a sealing property. That is, when the nipple is inserted into the nipple mounting portion, it has a groove formed on the outer periphery of the cylindrical portion, so when the nipple is inserted into the nipple mounting portion, the support ring is locked to the groove. The nipple can be fixed. In addition, since the seal member is provided on the outer periphery of the nipple, the seal member can be in contact with the outer sheet layer of the nipple mounting portion for sealing, and the permeation of fuel from the nipple mounting portion can be prevented.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a sectional view of a fuel tank 1 in which the nipple mounting structure of the present invention is used. 2 to 7 show the present invention applied to each part of the fuel tank 1, wherein FIGS. 2 and 3 are used for the inlet lower portion, FIG. 6 is used for the breather pod portion, and FIG. It shows what was used for the main port part.

As shown in FIG. 1, the fuel tank 1 is composed of an upper shell portion 10 and a lower shell portion 20 that are separately formed. The upper shell portion 10 and the lower shell portion 20 are respectively an inner resin layers 15 and 25 formed by injection molding, and a fuel-permeable multilayer resin that is bonded or fused to the outside after the inner resin layers 15 and 25 are molded. The outer sheet layers 16 and 26 composed of the sheet 3 are formed from two layers.
The fuel tank 1 can be divided not only into the upper shell portion 10 and the lower shell portion 20 but also into three or more.

In the upper shell portion 10, an inlet lower attachment portion 13 shown in FIG. 2 and a breather port attachment portion 14 shown in FIG. 6 are formed. The inlet lower mounting portion 13 is for mounting an inlet hose (not shown) for injecting fuel into the fuel tank 1, and the breather port mounting portion 14 allows gas in the fuel tank 1 to escape outside the tank when fuel is supplied. Therefore, a breather hose (not shown) is attached. Reference numeral 17 denotes a cut-off valve that prevents fuel leakage from the fuel tank 1 when the vehicle falls.
A hose clamp (not shown) for holding various hoses such as a fuel transfer hose may be provided on the upper surface of the upper shell portion 10.

  A sub tank 5 is formed on the inner surface of the lower shell portion 20, and the fuel pump unit 4 is attached in the sub tank 5. The sub tank 5 is provided so that the fuel pump unit 4 can reliably send the fuel in the fuel tank 1 to the engine when the vehicle is tilted or vibrated. A pipe extends from the fuel pump unit 4 and is connected to a fuel main port mounting portion 23 of the lower shell portion 20 shown in FIG. A fuel pipe (not shown) for sending fuel to the engine is attached to the fuel main port attachment portion 23.

As shown in FIG. 1, a joint peripheral edge 11 of the upper shell 10 and a joint peripheral 21 of the lower shell 20 are formed on the entire periphery of the opening of the upper shell 10 and the lower shell 20. , 21 are formed with flange portions 12 and 22 that project outward from the outer surface at substantially right angles over the entire circumference. The joining peripheral edge portions 11 and 21 and the flange portions 12 and 22 are fused to face each other.
As shown in FIG. 1, the flange portions 12 and 22 are formed so that the upper shell portion 10 and the main body of the lower shell portion 20 have a substantially L-shaped cross section.

The outer surfaces of the inner resin layers 15 and 25 of the upper shell portion 10 and the lower shell portion 20 are entirely fused up to the tips of the flange portions 12 and 22, and the fuel-permeable multilayer resin sheet 3 is integrally fused, as described above. The outer sheet layers 16 and 26 are configured. The fusion of the fuel-permeable multilayer resin sheet 3 can be performed by heating the surface of the fuel-permeable multilayer resin sheet 3. For this reason, fuel permeation can be prevented up to the entirety of the upper shell portion 10 and the lower shell portion 20 and the tips of the flange portions 12 and 22.

The fuel permeation-resistant multilayer resin sheet 3 is formed of, for example, a barrier layer for preventing fuel permeation in which a central layer is formed of ethylene vinyl alcohol copolymer (EVOH) or nylon, and modified polyethylene above and below the barrier layer. And a five-layer sheet composed of an outer layer formed of polyethylene (PE) on each outer surface of the adhesive layer.

The adhesive layer formed from the modified polyethylene has adhesion to both the barrier layer and the outer layer. For this reason, a barrier layer and an outer layer can be adhered firmly.
The outer layer of the fuel permeation-resistant multilayer resin sheet 3 can be made of polyethylene (PE) that is resistant to impact and abrasion, in which case the strength of the fuel tank 1 is increased and the barrier layer is protected. Can do. The inner resin layers 15 and 25 are bonded to the inner resin layers 15 and 25 when the inner resin layers 15 and 25 are made of an olefin-based synthetic resin, for example, high-density polyethylene (HDPE). And can be firmly joined.

Next, an embodiment of the structure of the nipple and the nipple mounting portion will be described with reference to FIGS.
First, based on FIGS. 7-10, the nipple attachment structure in the fuel main port part which is embodiment of this invention is demonstrated.

At the same time when the lower shell portion 20 is formed, a fuel main port mounting portion 23 that is a nipple mounting portion is formed in the lower shell portion 20 as shown in FIGS. The fuel main port mounting portion 23 has a cylindrical portion 23a that is formed in a cylindrical shape toward the inside of the fuel tank 1, and a bottom that is substantially perpendicular to the cylindrical portion 23a from the tip of the cylindrical portion 23a toward the center of the cylindrical portion 23a. Wall part 23b is extended. At the center of the bottom wall portion 23b, a hole into which a fuel main port 50 described later can be inserted is opened. The cylindrical portion 23a and the bottom wall portion 23b are formed at the same time when the lower shell portion 20 is injection-molded.

The outer sheet layer 26 is in close contact with the outer surfaces of the cylindrical portion 23 a and the bottom wall portion 23 b, that is, the outer surface of the fuel tank 1, continuously from the outer surface of the lower shell portion 20. The outer sheet layer 26 is bonded or fused to the lower shell portion 20, and the same applies to the cylindrical portion 23a and the bottom wall portion 23b. The outer sheet layer 26 is perforated in the fuel main port mounting portion 23 so that the fuel main port 50 can be inserted.

As shown in FIG. 8, the fuel main port 50, which is a nipple, includes a cylindrical tubular portion 51, a disk-shaped outer periphery of the tubular portion 51, and a lower shell portion 20 around the fuel main port mounting portion 23. The flange portion 52 that contacts the outer surface side, and the cylinder at a position on the fuel tank 1 inner side with respect to the bottom wall portion 23b of the fuel main port mounting portion 23 when the fuel main port 50 is inserted into the fuel main port mounting portion 23 The groove part 55 formed in the outer periphery of the shape part 51, and the step part 56 which protrudes in a step shape from the cylindrical part 51 in the lower surface of the flange part 52 are formed.

The fuel main port 50 is formed by injection molding separately from the fuel tank 1. As the material, a thermoplastic oil-resistant thermoplastic resin is used. For example, a synthetic resin such as polyethylene, polypropylene, polyacetal, and polyamide can be used. In addition, the inlet lower 30 and the breather port 40, which will be described later, can be formed using the same material.

A seal ring 54 as a seal member is attached below the step portion 56 of the fuel main port 50. The seal ring 54 is made of a fuel-resistant synthetic rubber.
As shown in FIG. 9, a support ring 60 is fitted inside the fuel tank 1 of the fuel main port attachment portion 23. As shown in FIG. 10, the support ring 60 has a cylindrical side wall portion 61 and a cylindrical portion 51 of the fuel main port 50 that extends in the direction perpendicular to the center from the tip of the side wall portion 61. Has a bottom side portion 62 having a hole into which the screw is inserted, and a locking claw 63 formed at the tip of the bottom side portion 62. Before the fuel main port 50 is attached to the fuel main port attachment portion 23, the support ring 60 is inserted into the fuel main port attachment portion 23 in advance as shown in FIG.

When the fuel main port 50 is inserted into the fuel main port mounting portion 23, as shown in FIG. 7, the flange portion 52 comes into contact with the outer surface of the lower shell portion 20, and the locking claw 63 of the support ring 60 is locked to the groove portion 55. Thus, the fuel main port 50 is fixed without being detached from the fuel main port attachment portion 23. Further, the seal ring 54 abuts on the outer sheet layer 26 in the fuel main port mounting portion 23 and the outer surface of the tubular portion 51 of the fuel main port 50 to prevent the fuel main port mounting portion 23 from permeating the fuel. it can.

Furthermore, since the side wall portion 61 of the support ring 60 is fitted and inserted into the outer periphery of the cylindrical portion 23a of the fuel main port mounting portion 23, the cylindrical portion 23a can prevent expansion due to aging deformation or swelling of fuel and a decrease in strength. In addition, the sealing performance of the fuel main port mounting portion 23 can be secured stably over a long period of time.
Further, since the bottom side portion 62 of the support ring 60 holds the surface of the bottom wall portion 23b of the fuel main port mounting portion 23 in the fuel tank 1, it is possible to prevent deformation and swelling of the bottom wall portion 23b, and The movement of the ring 60 can be prevented and the fuel main port 50 can be firmly fixed.

Next, an inlet lower mounting structure according to an embodiment of the present invention will be described with reference to FIGS.
At the time of forming the upper shell portion 10, an inlet lower attachment portion 13 that is a nipple attachment portion is formed in the upper shell portion 10. The inlet lower mounting portion 13 includes a cylindrical portion 13a formed in a cylindrical shape toward the inside of the fuel tank 1, and a bottom wall substantially perpendicular to the cylindrical portion 13a from the tip of the cylindrical portion 13a toward the center of the cylindrical portion 13a. A portion 13b is provided. At the center of the bottom wall portion 13b, a hole into which an inlet lower 30 described later can be inserted is opened.
The outer sheet layer 16 is in close contact with the outer surfaces of the cylindrical portion 13a and the bottom wall portion 13b, that is, the outer surface of the fuel tank 1, continuously from the outer surface of the upper shell portion 10.

The inlet lower 30 includes a cylindrical tubular portion 31, a flange portion 32 formed on the outer periphery of the tubular portion 31 and in contact with the outer surface side of the upper shell portion 10 around the inlet lower mounting portion 13, and the inlet lower 30 The groove 35 formed on the outer periphery of the tubular portion 31 and the flange portion 32 at a position inside the fuel tank 1 relative to the bottom wall portion 13b of the inlet lower attachment portion 13 when inserted into the inlet lower attachment portion 13. A step portion 36 is formed on the lower surface so as to protrude stepwise from the cylindrical portion 31.
Further, a check valve 33 is provided at the tip of the cylindrical portion 31 inside the fuel tank 1 to prevent the fuel from flowing back from the fuel tank 1.

A seal ring 34 as a seal member is attached below the step portion 36 of the inlet lower 30.
A support ring 60 is fitted inside the fuel tank 1 of the inlet lower mounting portion 13. As shown in FIG. 4, the support ring 60 has a side wall portion 61 formed in a cylindrical shape, and extends from the tip of the side wall portion 61 in a direction perpendicular to the center, and the cylindrical portion 31 of the inlet lower 30 is inserted in the center. A bottom portion 62 having a hole and a locking claw 63 formed at the tip of the bottom portion 62.

When the inlet lower 30 is inserted into the inlet lower mounting portion 13, the flange portion 32 comes into contact with the outer surface of the upper shell portion 10, the locking claw 63 of the support ring 60 is locked to the groove portion 35, and the inlet lower 30 is moved to the inlet lower portion. It is fixed without detaching to the attachment portion 13. Further, the seal ring 34 abuts on the outer sheet layer 16 in the inlet lower attachment portion 13 and the outer surface of the cylindrical portion 31 of the inlet lower 30, thereby preventing permeation of fuel from the inlet lower attachment portion 13.

Further, since the side wall portion 61 of the support ring 60 is fitted and inserted into the outer periphery of the cylindrical portion 13a of the inlet lower mounting portion 13, the cylindrical portion 13a can be prevented from aging and swelling of the fuel. The sealing performance of the attachment portion 13 can be ensured.
In addition, since the bottom side portion 62 of the support ring 60 holds the surface of the bottom wall portion 13b of the inlet lower mounting portion 13 in the fuel tank 1, it is possible to prevent the bottom wall portion 13b from being deformed or swelled, and to support the support ring. The movement of 60 can be prevented, and the inlet lower mounting portion 13 can be firmly fixed.
As shown in FIGS. 3 and 5, the side wall portion 61 of the support ring 60 can be eliminated and only the bottom side portion 62 and the locking claw 63 can be formed. In this case, similarly to the above, deformation and swelling of the bottom wall portion 13b can be prevented, and the support ring 60 can be prevented from moving, so that the inlet lower mounting portion 13 can be firmly fixed.

Next, based on FIG. 6, the nipple attachment structure in the breather port part which is embodiment of this invention is demonstrated.
Similar to the inlet lower attachment portion 13, a breather port attachment portion 14 that is a nipple attachment portion is formed in the upper shell portion 10 simultaneously with the formation of the upper shell portion 10. The breather port mounting portion 14 includes a cylindrical portion 14a formed in a cylindrical shape toward the inside of the fuel tank 1, and a bottom wall substantially perpendicular to the cylindrical portion 14a from the tip of the cylindrical portion 14a toward the center of the cylindrical portion 14a. A portion 14b is provided. At the center of the bottom wall portion 14b, a hole into which a breather port 40 described later can be inserted is opened.
The outer sheet layer 16 is in close contact with the outer surfaces of the cylindrical portion 14 a and the bottom wall portion 14 b, that is, the outer surface of the fuel tank 1, continuously from the outer surface of the upper shell portion 10.

The breather port 40, which is a nipple, has a cylindrical tubular portion 41 whose outer end is bent at a right angle, and an outer surface of the upper shell portion 10 around the breather port mounting portion 14 formed on the outer periphery of the tubular portion 41. The flange portion 42 to be in contact with the outer periphery of the tubular portion 41 at a position on the inner side of the fuel tank 1 with respect to the bottom wall portion 14b of the breather port mounting portion 14 when the breather port 40 is inserted into the breather port mounting portion 14. The formed groove portion 45 and a step portion 46 that protrudes in a stepped manner from the tubular portion 41 are formed on the lower surface of the flange portion 32.

A seal ring 44 as a seal member is attached below the step 46 of the breather port 40.
A support ring 60 is fitted inside the fuel tank 1 of the breather port mounting portion 14. The support ring 60 includes a side wall portion 61 formed in a cylindrical shape, and a bottom portion having a hole extending from the tip of the side wall portion 61 in a direction perpendicular to the center and into which the cylindrical portion 41 of the breather port 40 is inserted. 62 and a locking claw 63 formed at the tip of the bottom side portion 62.

When the breather port 40 is inserted into the breather port mounting portion 14, the flange portion 42 comes into contact with the outer surface of the upper shell portion 10, the locking claw 63 of the support ring 60 is locked to the groove portion 45, and the breather port 40 is moved to the breather port. It is fixed without detaching to the mounting portion 14. Further, the seal ring 34 abuts on the outer sheet layer 16 in the breather port mounting portion 14 and the outer surface of the tubular portion 41 of the breather port 40, thereby preventing fuel from permeating from the breather port mounting portion 14.

Further, since the side wall portion 61 of the support ring 60 is fitted on the outer periphery of the cylindrical portion 14a of the breather port mounting portion 14, the cylindrical portion 14a can prevent aged deformation and fuel swelling, and the breather port mounting portion. 14 sealability can be ensured.
Further, since the bottom side portion 62 of the support ring 60 holds the surface of the bottom wall portion 14b of the breather port mounting portion 14 in the fuel tank 1, deformation and swelling of the bottom wall portion 14b can be prevented, and the support ring The movement of 60 can be prevented and the breather port mounting portion 14 can be firmly fixed.

The embodiment of the present invention is shown and is a sectional view of a fuel tank. 1 is a cross-sectional view of an inlet lower portion of a fuel tank according to an embodiment of the present invention. The embodiment of the present invention is shown, and is a cross-sectional view of another inlet lower portion of the fuel tank. The embodiment of the present invention is shown and it is a perspective view of a support ring. The embodiment of the present invention is shown and it is a perspective view of other support rings. 1, showing an embodiment of the present invention, is a cross-sectional view of a breather port portion of a fuel tank. FIG. FIG. 2 is a cross-sectional view of a fuel main port portion of a fuel tank, showing an embodiment of the present invention. The embodiment of the present invention is shown and is a sectional view of a fuel main port. FIG. 4 is a cross-sectional view showing a process of inserting a fuel main port into a fuel main port mounting portion of a fuel tank, showing an embodiment of the present invention. FIG. 3 is a cross-sectional view of a fuel main port mounting portion of a fuel tank, showing an embodiment of the present invention. It is sectional drawing of the nipple attachment part of the conventional fuel tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank 10 Upper shell 13 Inlet lower attachment part 14 Breather port attachment part 13a, 14a, 23a Cylindrical part 13b, 14b, 23b Bottom wall part 15, 25 Inner resin layer 16, 26 Outer seat layer 20 Lower shell 23 Fuel main port attachment Part 30 Inlet lower 31, 41, 51 Tubular part 31, 42, 52 Flange part 34, 44, 54 Seal ring 35, 45, 55 Groove part 40 Breather port 50 Fuel main port 60 Support ring 63 Locking claw

Claims (6)

In the fuel tank nipple mounting structure for mounting a nipple that forms a liquid or gas inlet / outlet port of a thermoplastic synthetic resin fuel tank,
The fuel tank is integrally formed by fusing the joint peripheral portions of the upper shell portion and the lower shell portion, which are separately molded by injection molding, respectively, and the upper shell portion and the lower shell portion are each made of an inner resin. A layer and an outer sheet layer covering the outer surface of the inner resin layer,
The nipple mounting structure has a nipple mounting portion formed on a part of an outer wall of the upper shell portion or the lower shell portion, a nipple mounted on the nipple mounting portion, and a support ring for locking the nipple.
The nipple mounting portion extends from the inner surface of the cylindrical portion toward the center of the cylinder at a substantially right angle from the inner surface of the cylindrical portion, and a cylindrical portion formed by bulging in the inner direction of the fuel tank. A bottom wall portion having a hole for inserting the nipple at the center is provided, and the outer surface side of the fuel tank of the cylindrical portion and the bottom wall portion is covered with the outer sheet layer,
The nipple is inserted into the nipple mounting portion and allows a liquid or gas to flow therethrough, and a flange portion formed on the outer periphery of the cylindrical portion and in contact with the outer surface side of the fuel tank around the nipple mounting portion And a groove formed on the outer periphery of the cylindrical portion at a position on the fuel tank inner side than the bottom wall when the nipple is inserted into the nipple mounting portion, and the cylindrical shape below the flange portion. A seal member attached to the outer periphery of the part,
The support ring has a locking claw,
The nipple is inserted into the nipple mounting portion and the support ring, the seal member is in contact with the outer sheet layer of the nipple mounting portion, and the locking claw of the support ring is fitted into the groove portion of the nipple so that the nipple A nipple mounting structure for a fuel tank, wherein The support ring has a cylindrical side wall part, a bottom part having a hole extending from the tip of the side wall part in a direction perpendicular to the center of the side wall part and into which the cylindrical part of the nipple is inserted, and A locking claw formed at a tip of the bottom side, and a side wall portion of the support ring is fitted on an outer periphery of a cylindrical portion of the nipple mounting portion, and the bottom side is a bottom of the nipple mounting portion. 2. The nipple mounting structure for a fuel tank according to claim 1, wherein a surface of the wall portion in the fuel tank is held, and the locking claw is fitted into the groove portion of the nipple to lock the nipple.   The fuel tank nipple mounting structure according to claim 1, wherein the outer sheet layer is a fuel-permeable multi-layer resin sheet.   The step part which protrudes from a cylindrical part is formed in the lower surface of the flange part of the said nipple, The said sealing member was hold | maintained at the cylindrical part of the said nipple attachment part by this step part. The fuel tank nipple mounting structure described in 1.   The nipple is at least one of an inlet lower for injecting fuel into the fuel tank, a breather port through which gas inside the fuel tank enters and exits, and a fuel main port for discharging fuel inside the fuel tank. 5. The fuel tank nipple mounting structure according to claim 4. In the upper shell portion and the lower shell portion, the inner resin layer is formed of high-density polyethylene (HDPE), the outer sheet layer is formed of a fuel-permeable multilayer resin sheet, and the inner side of the fuel-permeable multilayer resin sheet is formed. The fuel tank according to any one of claims 1 to 5, wherein the layer in contact with the resin layer is formed of a material compatible with high-density polyethylene (HDPE).

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