JP2008168767A - Fuel tank - Google Patents

Abstract

Provided is a fuel tank in which a canister is integrally formed in a fuel tank and is excellent in air flow and sealing performance of a port mounting portion of an air release port or a discharge purge port.
A fuel tank (1) is integrally formed by fusing the joint peripheral portions of separately molded upper shell portion (10) and lower shell portion (20). The canister 30 is formed by integrally dropping a side wall 31 from the outer wall of the upper shell portion, the bottom wall 33 is formed separately from the upper shell portion, and the bottom wall 33 is fixed to the tip of the side wall 31. An air release port mounting portion 40 and a purge port mounting portion 50 are formed on the upper wall 37, and port mounting space 43 and 53 are formed from the upper wall in the air release port mounting portion and the purge port mounting portion. Thus, the port attachment side walls 41 and 51 were extended downward, and the filters 44 and 54 partitioning the space between the port attachment portion space and the fuel vapor absorbing member 35 of the canister were fixed to the tips of the port attachment side walls 41 and 51.
[Selection] Figure 2

Description

The present invention relates to an automotive fuel tank made of a thermoplastic synthetic resin, in which a canister is integrally formed.

The fuel tank for automobiles has an air suction port that removes the fuel vapor and discharges it according to the vapor pressure in the fuel tank and introduces the atmosphere into the tank. A purge port for discharging is attached, and a canister for removing the vapor of fuel contained in the air in the fuel tank so as not to be discharged from the atmosphere opening port to the atmosphere.
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 because it is easy to form a hollow shape. However, in the case of blow molding, it is difficult to attach a reinforcing rib, a pump unit, or the like inside.
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, etc., and then the joint peripheral edge part of the upper shell part and the lower shell part is welded to each other Thus, a method of forming a fuel tank is also performed.

In this case, in order to attach the canister, as shown in FIG. 5, a recess 117 capable of accommodating the canister 130 is formed in the upper shell portion 110 of the fuel tank 101, and the canister 130 and the fuel tank 101 are connected to each other. 118 (for example, refer to Patent Document 1). In this case, a predetermined space is required between the canister 130 and the fuel tank 101 to prevent heat generation, interference with the fuel tank 101, abnormal noise, and the like, resulting in wasted space.

In addition, an attachment structure between the fuel tank 101 and the canister 130 is required, which complicates the structure, takes time, and increases the cost.
Further, the connecting portion 118 that connects the canister 130 and the fuel tank 101 requires a large through-hole in the fuel tank 101, and the sealing structure is complicated to ensure sealing performance, which is disadvantageous for preventing fuel vapor leakage. there were.

Therefore, as shown in FIG. 6, the canister 230 is formed integrally with the fuel tank 201 (see, for example, Patent Document 2 and Patent Document 3).
The canister 230 is connected to the fuel tank 201 and the inside of the fuel tank 201 by a tube 205, and a purge port 250 that discharges the air containing the fuel vapor in the canister 230 to an intake system of the engine and an air release for sucking the atmosphere. A port 240 is formed.

In the atmosphere opening port 240 and the purge port 250, the open ends of the atmosphere opening port 240 and the purge port 250 are covered with a filter or the like so that the activated carbon inside the canister 230 is not discharged to the outside. However, the area of the opening tip is not sufficiently large, and the air flow resistance of the air release port 240 and the purge port 250 is increased by the filter, which is not efficient.
Further, the sealing structure for ensuring the sealing performance at the port mounting portion for mounting the atmosphere opening port 240 and the purge port 250 to the canister 230 is also complicated.

JP 2004-100513 A JP-A-11-240344 US Published Patent No. 2002-0011271

  Therefore, the present invention provides a fuel tank in which a canister is integrally formed in a fuel tank and is excellent in air circulation and sealing performance of a port mounting portion of an air release port or a discharge purge port.

In order to solve the above-mentioned problem, the present invention of claim 1 is a thermoplastic synthetic resin fuel tank in which a canister is integrally attached.
Each of the fuel tanks is integrally formed by fusing the joint peripheral portions of the upper shell portion and the lower shell portion that are separately molded by injection molding,
In the canister, the upper wall is composed of the outer wall of the upper shell part, the side wall is formed integrally with the outer wall of the upper shell part, the bottom wall is formed separately from the upper shell part, and the bottom wall is the side wall. The canister is filled with a fuel vapor absorbing member,
An air release port mounting part for attaching an air release port through which air enters and exits the canister and a purge port attachment part for attaching a purge port for discharging air containing fuel vapor from the canister are formed on the upper wall. The port mounting portion and the purge port mounting portion each have a port mounting portion side wall extending downward from the upper wall so as to form a port mounting portion space. Each of the fuel tanks has a front end that is open and a filter that partitions the space between the port mounting portion and the fuel vapor absorbing member of the canister is fixed to the tip of the side wall of the port mounting portion.

In the first aspect of the present invention, the fuel tank is integrally formed by fusing the joint peripheral edge portions of the upper shell portion and the lower shell portion which 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. In addition, component mounting portions 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 easily improved.

In the canister, the upper wall is composed of the outer wall of the upper shell portion, and the side wall is integrally formed by hanging from the outer wall of the upper shell portion. Therefore, the upper wall and the side wall are simultaneously formed when the upper shell portion is injection-molded. Can be formed.
The bottom wall is formed separately from the upper shell portion, the bottom wall is fixed to the tip of the side wall, and the canister is filled with a fuel vapor absorbing member. For this reason, the box shape of the canister can be easily formed by fixing the bottom wall, and it is easy to fill the inside with the fuel vapor absorbing member.

An air release port mounting portion for attaching an air release port through which air enters and exits the canister and a purge port attachment portion for attaching a purge port for discharging air containing fuel vapor from the canister were formed on the upper wall. For this reason, when the upper shell portion is injection-molded, the atmosphere opening port mounting portion and the purge port mounting portion can be formed at the same time as the canister molding, and manufacturing is easy.

Since the port mounting portion side wall extends downward from the upper wall so that the port mounting portion space is formed from the upper wall, the port mounting portion space and the purge port mounting portion are simultaneously formed with the upper shell portion. Can be formed, and the port attachment space can be formed in close contact with the upper wall.

The front ends of the atmosphere release port and the purge port were opened in the port mounting space, and a filter that partitioned the port mounting space and the fuel vapor absorbing member of the canister was fixed to the front end of the port mounting side wall. For this reason, the front end of the air release port and the purge port are positioned in the port attachment space so that the filter is not directly blocked. In addition, the area of the filter can be increased and the circulation efficiency of the atmosphere is better than when a filter is attached to the tip of the atmosphere opening port and the purge port. Further, since the atmosphere release port and the purge port are attached to the port attachment portion separately from the filter, the attachment is easy.

According to the second aspect of the present invention, the atmosphere release port and the purge port are formed separately from the atmosphere release port attachment portion and the purge port attachment portion, respectively. The fuel tank is locked together with the seal member.

In the second aspect of the present invention, since the atmosphere release port and the purge port are formed separately from the atmosphere release port attachment portion and the purge port attachment portion, the atmosphere release port attachment portion and the purge port attachment portion are provided. The structure is simple and easy to manufacture.
Since the air release port mounting part and the purge port mounting part are respectively locked together with the seal member, it can be easily assembled by fitting the air release port and the purge port into the air release port mounting part and the purge port mounting part. It can be attached and sealability can be secured.

The present invention of claim 3 is a fuel tank in which the atmosphere release port and the purge port are integrally extended from the atmosphere release port attachment portion and the purge port attachment portion to the outside of the fuel tank.

According to the third aspect of the present invention, since the atmosphere release port and the purge port are formed integrally extending from the atmosphere release port attachment portion and the purge port attachment portion to the outside of the fuel tank, the upper shell portion is formed. At the same time, the atmosphere release port, purge port, atmosphere release port attachment portion and purge port attachment portion can be formed at the same time, making the manufacture easy and sealing the atmosphere release port attachment portion and the purge port attachment portion. Can be secured.

According to the fourth aspect of the present invention, the atmosphere release port and the purge port are formed separately from the atmosphere release port attachment portion and the purge port attachment portion, and are welded to the atmosphere release port attachment portion and the purge port attachment portion. Or it is a fuel tank attached by gluing.

In the present invention of claim 4, since the air release port and the purge port are formed separately from the air release port mounting portion and the purge port mounting portion, respectively, the air release port mounting portion and the purge port mounting portion The structure is simple and easy to manufacture.
Since it is attached to the atmosphere opening port attachment portion and the purge port attachment portion by welding or bonding, the sealing property of the atmosphere opening port attachment portion and the purge port attachment portion can be secured.

The present invention of claim 5 is a fuel tank in which a partition wall is extended from the upper wall of the canister so as to have a gap between the bottom wall and the bottom wall.

In the present invention of claim 5, the partition wall is extended from the upper wall of the canister downward so as to have a gap between the bottom wall and the passage path of the air flowing through the fuel vapor absorbing member inside the canister The fuel vapor in the air can be reliably absorbed.

The present invention of claim 6 is a fuel tank in which a bottom partition wall is extended from the bottom wall of the canister so as to have a gap between the upper wall and the upper wall.

According to the sixth aspect of the present invention, the bottom partition wall is extended upward from the bottom wall of the canister so as to have a gap between the upper wall and the air flow path through the fuel vapor absorbing member inside the canister. The fuel vapor in the air can be reliably absorbed.

The present invention of claim 7 is the fuel tank in which the filter fixed to the tip of the side wall of the port attachment portion is welded or fitted.

In the present invention of claim 7, since the filter fixed to the tip of the side wall of the port mounting portion is welded or fitted, it is easy to mount the filter.

The present invention of claim 8 is a fuel tank in which a sponge member is provided at the bottom inside the canister, and activated carbon is filled on the sponge member as a fuel vapor absorbing member.

In the present invention of claim 8, since a sponge member having good air permeability is provided in the bottom of the canister, and activated carbon is filled on the sponge member as a fuel vapor absorbing member, the activated carbon filled in the canister is used. By pushing up, the gap can be eliminated, and the fuel vapor can be reliably removed from the air flowing through the canister.
Since activated carbon is used, fuel vapor can be reliably removed from the air flowing into the canister from the fuel tank, and fuel vapor adsorbed on the activated carbon can be easily removed by air circulation. Can also be used.

In the present invention of claim 9, the upper shell portion and the lower shell portion are made of polyoxymethylene (POM), high density polyethylene (HDPE), ethylene vinyl alcohol copolymer (EVOH), nylon, polybutylene terephthalate, polyethylene terephthalate, polyphenylene. It is a fuel tank formed from at least one material of sulfide (PPS).

In the present invention of claim 9, the upper shell portion and the lower shell portion are formed of polyoxymethylene (POM), high density polyethylene (HDPE), ethylene vinyl alcohol copolymer (EVOH), nylon, polybutylene terephthalate, polyethylene terephthalate, polyphenylene. It was formed from at least one material of sulfide (PPS). For this reason, while being able to manufacture a high-strength fuel tank, it is possible to manufacture a fuel tank that is excellent in the permeation-preventing property of fuel stored in the fuel tank and that can prevent permeation of fuel.

According to the present invention of claim 10, in the upper shell portion and the lower shell portion, the inner resin layer is formed by injection molding of high density polyethylene (HDPE), and the outer surface of the inner resin layer is an outer sheet made of a fuel-permeable multilayer resin sheet. The fuel tank formed of a material compatible with high-density polyethylene (HDPE) is a layer formed by the layer and in contact with the inner resin layer of the fuel-permeable multilayer resin sheet.

In the present invention of claim 10, since the inner shell is formed by injection molding of high density polyethylene (HDPE) in the upper shell portion and the lower shell portion, the impact strength of the fuel tank can be increased, and the molten resin High fluidity and easy injection molding.
Since the outer surface of the inner resin layer is formed of an outer sheet layer made of a fuel-permeable multi-layer resin sheet, the outer side of the inner resin layer of the upper shell portion and the lower shell portion is covered with the fuel-permeable multi-layer resin sheet, and the fuel When fuel oil is put into the tank, permeation of fuel oil can be prevented.

Since 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), the inner resin layer and the outer sheet layer can be firmly fused. . Moreover, if the outer layer of the fuel-permeable multilayer resin sheet is made of high-density polyethylene (HDPE), the strength of the fuel tank can be increased.

Since the port attachment portion side wall extends downward from the upper wall in the air release port attachment portion and the purge port attachment portion, a port attachment space can be formed simultaneously with the molding of the upper shell portion. Because the filter that partitions the port mounting space and the fuel vapor absorbing member of the canister is fixed to the front end of the port mounting side wall in the port mounting space, the filter does not directly block the front end of the air release port and the purge port. The area of the filter can be increased, and the air circulation efficiency is good.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of a fuel tank 1 in which a canister 30 of the present invention is used. 2 to 4 show first to third embodiments of the present invention and are sectional views of a canister 30 attached to the fuel tank 1.

First, a first embodiment will be described with reference to FIGS.
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.

The upper shell portion 10 is integrally formed with a canister 30 shown in FIG. 1 for preventing the fuel vapor in the fuel tank 1 from being discharged. In addition, an inlet mounting portion 13 and a blister port mounting portion 14 are formed on the upper wall 37 of the canister 30. The inlet mounting portion 13 is for mounting an inlet hose (not shown) for injecting fuel into the fuel tank 1, and the blister port mounting portion 14 is a blister hose (see FIG. 5) for releasing air in the fuel tank 1 when fuel is supplied. (Not shown).
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 the fuel main port mounting portion 23 of the lower shell portion 20. 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, 22 projecting outward from the outer surface over the entire circumference. The joining peripheral edge parts 11 and 21 and the flange parts 12 and 22 are welded so as to face each other.
The flange portions 12 and 22 are formed to have a substantially L-shaped cross section from the upper shell portion 10 and the main body of the lower shell portion 20.

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 formed 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, based on FIG. 2, the first embodiment will be described focusing on the structure of the canister 30.
The canister 30 is integrally formed inside the outer wall of the upper shell portion 10. The canister 30 is formed in a box shape, and the upper wall 37 is constituted by the outer wall of the upper shell portion 10. The side wall 31 of the canister 30 is formed to continuously and integrally hang down from the inner resin layer 15 of the upper shell portion 10 so as to constitute the outer surface of the canister 30.

Furthermore, the partition wall 32 can be extended downward from a substantially central portion of the upper wall 37 so as to have a gap with a bottom wall 33 described later. The partition wall 32 and the side wall 31 are simultaneously formed when the inner resin layer 15 of the upper shell portion 10 is injection-molded. For this reason, it does not require the effort of shaping | molding and is easy.

Further, the bottom wall 33 is formed separately from the upper shell portion. The bottom wall 33 is welded or bonded to the tip of the side wall 31. In this way, the outer wall of the canister 30 can be formed. In addition, the bottom partition wall 34 is extended upward so that there is a gap between the bottom wall 33 and the top wall 37 so that the partition wall 32 and the canister 30 are displaced to form an air flow path. can do.

Before welding or adhering the bottom wall 33 to the tip of the side wall 31, the canister 30 is filled with activated carbon 35 as a fuel vapor absorbing member, and a sponge member 36 having good air permeability is provided in a portion in contact with the bottom wall 33. It has been. For this reason, the activated carbon 35 is pressed by the sponge member 36 so that no gap is generated between the activated carbon 35 inside the canister 30 due to vibration during use, etc., so that filling can be continued without any gap. It is possible to reliably contact the air flowing through the activated carbon 35 and to reliably remove the fuel vapor from the air.

Since the activated carbon 35 is used, the fuel vapor can be reliably removed from the air flowing from the fuel tank 1 into the canister 30 and the engine is operated to send air to the intake system from the atmosphere into the canister 30. When air flows in, the fuel vapor adsorbed on the activated carbon 35 can be easily removed by the air flow, and the fuel vapor can be adsorbed on the activated carbon 35 again. In this way, the activated carbon 35 can be used repeatedly many times.

When the partition wall 32 is formed from the upper wall 37 and shifted from the partition wall 32, and the bottom partition wall 34 is formed from the bottom wall 33, as shown in FIG. The fuel vapor can be bent and formed long, and the fuel vapor can be adsorbed and desorbed reliably. Note that only one of the partition wall 32 and the bottom partition wall 34 can be formed. Further, when the canister 30 is formed to be elongated and a sufficient distribution path can be secured, neither the partition wall 32 nor the bottom partition wall 34 may be used.

A cut-off valve 61 is provided inside the upper shell portion 10, and the cut-off valve 61 and the gas-liquid separation chamber 60 are connected by a tube 62. The cut-off valve 61 is attached to the inner surface of the outer wall of the upper shell portion 10. The cut-off valve 61 functions to allow only the gas in the fuel tank 1 to pass so that liquid fuel does not flow into the canister 30 from the fuel tank 1. As a result, only gas can be sent to the canister 30 regardless of the fuel level in the fuel tank 1.

A gas-liquid separation chamber 60 is formed near the purge port 55 of the bottom wall 33, and a bidirectional check valve 63 is provided in the gas-liquid separation chamber 60. The gas-liquid separation chamber 60 communicates with the bottom wall 33, and a filter 65 is attached to the communicating portion.
The air in the fuel tank 1 sent from the tube 62 to the gas-liquid separation chamber 60 is separated into gas and liquid in the gas-liquid separation chamber 60, and only the gas is sent into the canister 30.

The upper wall 37 of the canister 30 is purged with an air release port mounting portion 40 for attaching an air release port 45 for allowing air to enter and exit the canister 30 and a purge port 55 for discharging air from the canister 30 to the intake system of the engine. A port mounting portion 50 is formed. As a result, when the pressure in the fuel tank 1 rises, the canister 30 passes the air containing the fuel vapor in the fuel tank 1 from the fuel tank 1 through the cutoff valve 61 and the gas-liquid separation chamber 60. The canister 30 can remove the fuel vapor and discharge it to the atmosphere.

Further, when the pressure in the fuel tank 1 drops, air can be introduced from the atmosphere opening port 45 via the canister 30.
Further, during engine operation, air can be sent from the purge port 55 to the intake system of the engine via the canister 30. At this time, the fuel vapor adsorbed on the activated carbon of the canister 30 is removed as described above. be able to.

The port opening portion 40 and the purge port mounting portion 50 for opening to the atmosphere extend the port attachment portion side walls 41 and 51 downward from the upper wall 37 so as to form the outer walls of the port attachment portion spaces 43 and 53, respectively. In the port attachment space 43, 53, when the air release port 45 and the purge port 55 are attached, the tips of the air release port 45 and the purge port 55 may be located in the port attachment space 43, 53. Form as large as possible.

Inside the port attachment side walls 41 and 51, port attachment side wall protrusions 42 and 52 are formed inwardly, respectively. The port attaching portion side walls 41, 51 and the port attaching portion side wall protrusions 42, 52 can be simultaneously formed when the inner resin layer 15 of the upper shell portion 10 is formed, similarly to the side wall 31. For this reason, molding can be performed at once, and it is not time-consuming.
The outer side sheet layer 16 made of the fuel-permeable multilayer resin sheet 3 extends continuously from the outer surface of the upper shell portion 10 on the inner side of the port mounting portion side walls 41, 51 and the upper surface of the port mounting portion side wall protrusions 42, 52, It is fused.

Filters 44 and 54 are bonded or welded to the tips of the port attachment side walls 41 and 51, respectively. The filters 44 and 54 are formed of a nonwoven fabric or the like. When the filters 44 and 54 are formed of a synthetic fiber non-woven fabric, they can be directly welded to the tips of the port attachment side walls 41 and 51. Further, the filters 44 and 54 can be put in a frame, and the frame can be locked or bonded to the tips of the port attachment side walls 41 and 51.

Since the filters 44 and 54 are fixed to the tips of the port attachment side walls 41 and 51, respectively, the activated carbon 35 filled in the canister 30 does not enter the port attachment space 43 and 53. Further, the tips of the air release port 45 and the purge port 55 are not directly blocked by the filters 44 and 54, and the filter 44 and 54 are attached to the tips of the air release port 45 and the purge port 55. The area of 44, 54 can be enlarged, air flow resistance is small, and air flow efficiency is good.

The air release port 45 and the purge port 55 have leg portions 46 and 56 each having a hook portion that can be locked to the port mounting portion side wall protrusions 42 and 52 at the tip portions. A slit is formed. Seal rings 47 and 57 which are seal members are fitted in the leg portions 46 and 56.

When the air release port 45 and the purge port 55 are inserted into the air release port mounting portion 40 and the purge port mounting portion 50, respectively, the legs 46 and 56 are bent and locked to the port mounting portion side wall protrusions 42 and 52. Is done. At that time, the seal rings 47 and 57 are in contact with the outer sheet layer 16 on the upper surfaces of the port attachment side wall projections 42 and 52, respectively, and the atmosphere release port 45 and the purge port 55, respectively, and the atmosphere release port attachment portion 40 and The gap between the purge port mounting portion 50 can be sealed to prevent the fuel vapor from permeating.
The air release port 45 and the purge port 55 must be formed of a fuel-permeable synthetic resin.

Further, the front ends of the air release port 45 and the purge port 55 are opened in the port attachment space 43, 53. For this reason, the tips of the air release port 45 and the purge port 55 are not directly blocked by the filters 44 and 54. Furthermore, since the filters 44 and 54 are fixed to the port attachment side walls 41 and 51, air flows through the port attachment space 43 and 53, so that the air circulation efficiency is good.

Next, based on FIG. 3, a second embodiment of the present invention will be described focusing on the structure of the canister 30. In the second embodiment, the upper shell portion 10 is formed of one layer of thermoplastic synthetic resin, and the atmosphere release port 45, the purge port 55, the atmosphere release port attachment portion 40, and the purge port attachment portion 50. The other parts are different, and the other parts are the same as in the first embodiment. For this reason, a different part is demonstrated and description is abbreviate | omitted about the same 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. Each of the upper shell portion 10 and the lower shell portion 20 is formed by injection molding of a thermoplastic synthetic resin.
The thermoplastic synthetic resin is at least one of polyoxymethylene (POM), high density polyethylene (HDPE), ethylene vinyl alcohol copolymer (EVOH), nylon, polybutylene terephthalate, polyethylene terephthalate, and polyphenylene sulfide (PPS). A synthetic resin selected from the materials can be used. For this reason, while being able to manufacture a fuel tank with high strength, it is possible to manufacture a fuel tank that is excellent in preventing permeation of liquid stored in the fuel tank and that can prevent permeation of liquid.

The port opening portion 40 for air release and the purge port mounting portion 50 have port attachment side walls 41 and 51 extending downward from the upper wall 37 so as to form port attachment space 43 and 53, respectively. In the port attachment space 43, 53, when the air release port 45 and the purge port 55 are attached, the tips of the air release port 45 and the purge port 55 may be located in the port attachment space 43, 53. Form as large as possible. However, the port attachment side wall protrusions 42 and 52 are not formed on the inside of the port attachment side walls 41 and 51, respectively.

The port attachment side walls 41 and 51 can be formed at the same time as the inner resin layer 15 of the upper shell portion 10 is formed, similarly to the side wall 31. For this reason, molding can be performed at once, and it is not time-consuming.
Filters 44 and 54 are bonded or welded to the tips of the port attachment side walls 41 and 51, respectively. The filters 44 and 54 are formed of a nonwoven fabric or the like. The attachment of the filters 44 and 54 is the same as in the first embodiment.

The air release port 45 and the purge port 55 are formed so as to extend integrally from the portions of the air release port mounting portion 40 and the purge port mounting portion 50 of the upper wall 37 toward the outside of the fuel tank 1, respectively. Yes. For this reason, when the upper shell portion 10 is injection-molded, it can be molded at the same time as the air release port 45 and the purge port 55, and the molding is easy.
Further, the seal between the air release port mounting portion 40 and the air release port 45, and the purge port mounting portion 50 and the purge port 55 have no connection portion, and do not require a seal member, thereby reliably preventing the passage of fuel vapor. it can.

Furthermore, the tips of the atmosphere release port 45 and the purge port 55 open to the port mounting spaces 43 and 53, respectively, and the filters 44 and 54 directly block the tips of the atmosphere release port 45 and the purge port 55. In the same manner as in the first embodiment, the areas of the filters 44 and 54 can be increased, and the air circulation efficiency is good. In addition, bent tubes can be inserted into the atmosphere release port 45 and the purge port 55, respectively.

Next, based on FIG. 4, a third embodiment will be described focusing on the structure of the canister 30. In the third embodiment, similarly to the second embodiment, the upper shell portion 10 is formed of one layer of a thermoplastic synthetic resin. However, the atmospheric release port 45 and the purge port 55 are formed separately from the atmospheric release port mounting portion 40 and the purge port mounting portion 50, and the other portions are the same as in the second embodiment. . For this reason, a different part from 2nd Embodiment is demonstrated and description is abbreviate | omitted about the same part.

In the air release port mounting portion 40 and the purge port mounting portion 50, the port mounting portion side walls 41 and 51, the port mounting portion spaces 43 and 53, and the filters 44 and 54 are the same as in the second embodiment.
The air release port 45 and the purge port 55 are formed separately from the air release port mounting portion 40 and the purge port mounting portion 50, respectively.

The air release port 45 and the purge port 55 are formed with flanges 48 and 58 on the outer periphery of the leg portions 46 and 56.
When the air release port 45 and the purge port 55 are inserted into the air release port mounting portion 40 and the purge port mounting portion 50, respectively, the ends of the leg portions 46 and 56 of the air release port 45 and the purge port 55 are connected to the port mounting portion. Opening into the spaces 43 and 53, the flanges 48 and 58 abut against the outer surface of the upper wall 37. Therefore, the tips of the air release port 45 and the purge port 55 are not directly covered by the filters 44 and 54, and the area of the filters 44 and 54 can be increased, and the air circulation efficiency is good.

The flanges 48 and 58 of the air release port 45 and the purge port 55 are welded or bonded to the upper wall 37. The upper shell portion 10 is formed of one layer and there is no outer sheet layer 16. For this reason, the air release port mounting portion 40, the air release port 45, the purge port mounting portion 50, and the purge port 55 are firmly fixed to the upper shell portion 10, respectively. In addition, the connection between the air release port mounting portion 40 and the air release port 45 and the purge port mounting portion 50 and the purge port 55 is reliable without requiring a seal member.

The embodiment of the present invention is shown and is a sectional view of a fuel tank. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a canister formed integrally with a fuel tank according to a first embodiment of the present invention. FIG. 5 is a cross-sectional view of a canister formed integrally with a fuel tank according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view of a canister formed integrally with a fuel tank according to a third embodiment of the present invention. FIG. 2 is a perspective view showing a conventional fuel tank as viewed from above. FIG. 10 is a sectional view of a canister portion, showing another conventional fuel tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank 10 Upper shell part 15, 25 Inner resin layer 16, 26 Outer sheet layer 20 Lower shell part 30 Canister 31 Side wall 32 Partition wall 33 Bottom wall 34 Bottom partition wall 35 Fuel vapor absorption member (activated carbon)
36 Sponge member 37 Upper wall 40 Atmospheric release port mounting part 41, 51 Port mounting part side wall 43, 53 Port mounting part space 44, 54 Filter 45 Atmospheric release port 50 Purge port mounting part 55 Purge port

Claims (10)

In a fuel tank made of thermoplastic synthetic resin with a canister attached integrally,
The fuel tank is integrally formed by fusing the joint peripheral edge portions of the upper shell portion and the lower shell portion that are separately molded by injection molding.
In the canister, the upper wall is formed from the outer wall of the upper shell portion, the side wall is integrally formed from the outer wall of the upper shell portion, the bottom wall is formed separately from the upper shell portion, The bottom wall is fixed to the end of the side wall, the canister is filled with a fuel vapor absorbing member,
Formed on the upper wall is an air release port mounting portion for attaching an air release port through which air enters and exits the canister, and a purge port mounting portion for attaching a purge port for discharging air containing fuel vapor from the canister, Each of the air release port mounting portion and the purge port mounting portion has a port mounting portion side wall extending downward from the upper wall so as to form a port mounting portion space. A fuel tank characterized in that a front end of each of the port and the purge port is open, and a filter for partitioning between the port mounting portion space and the fuel vapor absorbing member of the canister is fixed to a front end of each side wall of the port mounting portion. . The air release port and the purge port are formed separately from the air release port mounting portion and the purge port mounting portion, and are locked to the air release port mounting portion and the purge port mounting portion together with a seal member, respectively. 2. The fuel tank according to claim 1, wherein: 2. The fuel tank according to claim 1, wherein the atmosphere release port and the purge port are formed so as to be integrally extended from the atmosphere release port attachment portion and the purge port attachment portion to the outside of the fuel tank. The atmosphere release port and the purge port are formed separately from the atmosphere release port attachment portion and the purge port attachment portion, and are attached by welding or bonding to the atmosphere release port attachment portion and the purge port attachment portion. 2. The fuel tank according to claim 1, wherein The fuel tank according to any one of claims 1 to 4, wherein a partition wall is extended downward from an upper wall of the canister so as to have a gap between the bottom wall and the bottom wall. The fuel tank according to any one of claims 1 to 5, wherein a bottom partition wall is extended upward from a bottom wall of the canister so as to have a gap between the top wall and the upper wall. The fuel tank according to any one of claims 1 to 6, wherein the filter fixed to the tip of the side wall of the port attachment portion is welded or fitted. The fuel tank according to any one of claims 1 to 7, wherein a sponge member is provided at the bottom of the canister, and activated carbon is filled on the sponge member as a fuel vapor absorbing member. The upper shell portion and the lower shell portion are at least one of polyoxymethylene (POM), high density polyethylene (HDPE), ethylene vinyl alcohol copolymer (EVOH), nylon, polybutylene terephthalate, polyethylene terephthalate, and polyphenylene sulfide (PPS). The fuel tank according to any one of claims 1 to 8, wherein the fuel tank is formed of one kind of material. The upper shell portion and the lower shell portion are formed by forming an inner resin layer by injection molding of high density polyethylene (HDPE), and forming an outer surface of the inner resin layer by an outer sheet layer made of a fuel-permeable multilayer resin sheet, The fuel tank according to any one of claims 1 to 8, wherein a 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).

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