JP2008174074A - Fuel tank - Google Patents

Abstract

The present invention provides a fuel tank that is formed with a sub-tank integrally formed in a lower shell portion of a fuel tank so that a fuel pump unit can be easily attached and detached and is excellent in fuel delivery.
In a fuel tank made of a thermoplastic synthetic resin in which an upper shell portion and a lower shell portion, which are separately molded separately, are fused, a sub tank is integrally formed with the lower shell portion, and fuel is contained in the sub tank. The fuel pump unit 40 for feeding out was attached detachably. The fuel pump unit 40 includes at least a fuel pump 43 and a unit casing 47. The unit casing 47 houses the fuel pump 43 in the unit casing upper part 47a, the unit casing lower part 47b is formed so as to have a space extending laterally from the upper part of the unit casing, and the filter 52 is provided so as to cover the lower part of the unit casing. The fuel tank is detachably attached.
[Selection] Figure 2

Description

The present invention relates to a fuel tank for automobiles made of thermoplastic synthetic resin to which a fuel pump unit is detachably attached.

The fuel tank for automobiles is provided with a fuel pump unit including a fuel pump that sends fuel in the fuel tank to the engine.
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, since it is formed into a hollow shape at a time, it is difficult to attach components such as a fuel pump inside, or to form attachment ribs or reinforcing ribs for attaching a fuel pump unit or the like. there were.
Therefore, as shown in FIG. 9, the fuel pump unit 140 is fixed to the outer wall of the fuel tank so that it can be detached from the outside of the fuel tank (see, for example, Patent Document 1).

  Therefore, in order to facilitate the assembly of the fuel pump unit, the sub tank, the fuel pump 143, the filters 141, 142 and the like are integrated into a module. However, when modularized, it is difficult to take out only the parts necessary for repair and inspection. Further, since the fuel pump unit 140 is attached to the upper wall of the fuel tank, a mechanism for constantly pressing the sub-tank against the lower wall of the fuel tank 1 is required, the structure becomes complicated, and the cost increases.

  Therefore, in recent years, the fuel tank made of synthetic resin is divided into upper and lower parts, the upper shell part and the lower shell part are separately molded by injection molding or the like, and a fuel pump unit or the like is attached to the lower shell part, and then the upper shell part There is also a method of forming a fuel tank by welding the joining peripheral edge portions of the lower shell portion to each other (see, for example, Patent Document 2 and Patent Document 3).

In this case, in order to attach the fuel pump unit, a sub-tank is formed in the lower shell portion, an attachment rib necessary for attaching the fuel pump unit is formed in the sub-tank, and locked to the attachment rib. In this case, a filter is attached to the fuel inlet at the lower part of the fuel pump unit in order to remove foreign matter in the fuel tank.

However, removal and repair of the fuel pump unit is not always easy, and the area of the fuel intake port is not sufficiently large, and the flow resistance of the fuel is increased by the filter, which is not efficient.
Japanese Patent Laying-Open No. 2005-256741 JP-A-11-198933 US Pat. No. 6,948,511

  Accordingly, the present invention provides a fuel tank that is excellent in fuel delivery by forming a sub-tank integrally with the lower shell portion of the fuel tank, making it easy to attach and remove the fuel pump unit.

In order to solve the above-mentioned problem, the present invention of claim 1 is made of a thermoplastic synthetic resin which 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. In the fuel tank of
In the lower shell part, a sub tank is formed integrally with the lower shell part, and a fuel pump unit for sending fuel into the sub tank is detachably attached.
The fuel pump unit has at least a fuel pump and a unit casing. The unit casing stores the fuel pump in the upper part of the unit casing, and the lower part of the unit casing is expanded in the lateral direction to have a space. The fuel tank is formed and removably attached with a filter so as to cover the lower part of the unit casing.

In the first aspect of the present invention, the fuel tank is integrally formed by fusing together the joining peripheral edge portion of the upper shell portion and the lower shell portion made of thermoplastic synthetic resin 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.

Since the sub tank is formed integrally with the lower shell portion in the lower shell portion, the sub tank can be formed at the same time when the lower shell portion is formed, and the manufacturing efficiency is good.
Since the fuel pump unit for delivering fuel to the sub tank is detachably attached, it can be easily removed when the fuel pump unit is repaired or inspected. Further, when the fuel tank is manufactured, the fuel pump unit can be easily attached in the fuel tank by attaching it to the lower shell portion before fusing the joining peripheral edge portions.

The fuel pump unit has at least a fuel pump and a unit casing. Since the unit casing houses the fuel pump in the upper part of the unit casing, the fuel pump is securely held in the unit casing, and vibration during traveling It is securely held in the fuel tank. Also, the fuel pump can be easily removed by removing the unit casing.

The lower part of the unit casing is formed so as to have a space extending laterally from the upper part of the unit casing, and a filter is detachably attached so as to cover the lower part of the unit casing. For this reason, the tip of the fuel inlet of the fuel pump is positioned in the space formed in the lower part of the unit casing, and the filter is not directly blocked. Further, the area of the filter can be increased and the fuel suction efficiency is better than when a filter is attached to the tip of the fuel suction port of the fuel pump. Moreover, since the filter is attached to the lower part of the unit casing, attachment and removal are easy.

The present invention of claim 2 is a fuel tank in which a plurality of mounting ribs are erected in the sub tank and the lower part of the unit casing is locked to the mounting ribs.

In the present invention of claim 2, since a plurality of mounting ribs are erected in the sub-tank, the mounting rib can be formed simultaneously with the sub-tank when the mounting rib is formed in the lower shell portion, and manufacturing is easy. Since the lower part of the unit casing is locked to the mounting rib, the fuel pump unit can be securely mounted in the sub tank, and the fuel pump unit is securely held even if the vehicle is vibrated or the fuel tank expands or contracts due to temperature changes. be able to.

According to the third aspect of the present invention, the mounting rib in the sub-tank is formed with a locking rod at the tip, the side surface of the lower part of the unit casing is formed with a locking projection on the outer surface, and the locking rib of the mounting rib is the unit casing. This is a fuel tank that is inserted into the locking hole of the locking projection and locked.

According to the third aspect of the present invention, the mounting rib in the sub-tank is formed with a locking hook at the tip, the side surface of the lower part of the unit casing is formed with a locking protrusion on the outer surface, and the locking rib of the mounting rib is the unit casing. It is inserted into the locking hole of the locking protrusion and locked. For this reason, when attaching the fuel pump unit to the mounting rib, simply pressing the fuel pump unit from the upper side to the lower side of the mounting rib will cause the tip of the mounting rib to bend and the locking rod to the locking hole of the locking projection. The fuel pump unit can be securely held by being engaged.

According to the present invention of claim 4, the mounting rib in the sub-tank is formed with a locking groove at the tip, the side surface of the lower part of the unit casing is formed with a locking protrusion on the outer surface, and the unit casing is formed in the locking groove of the mounting rib. This is a fuel tank in which the outer peripheral portion of the locking hole of the locking protrusion is inserted and locked.

According to the fourth aspect of the present invention, the mounting rib in the sub tank is formed with a locking groove at the tip, the side surface of the lower part of the unit casing is formed with a locking projection on the outer surface, and the unit casing is formed in the locking groove of the mounting rib. The outer peripheral portion of the locking hole of the locking projection is inserted and locked. For this reason, when attaching the fuel pump unit to the mounting rib, it is only necessary to press the fuel pump unit from the upper side to the lower side of the mounting rib, and inside the locking groove of the mounting rib, the outer periphery of the locking hole of the locking projection The portion is fitted and the fuel pump unit can be securely held.

In the fifth aspect of the present invention, the plurality of mounting ribs in the sub-tank are formed with locking corners bent in an L shape in the direction in which the tips face each other, and the lower part of the unit casing has a locking projection on the outer surface. The fuel tank is formed and locked by slidingly engaging a locking projection of the unit casing with a locking corner of the mounting rib.

In the present invention of claim 5, the plurality of mounting ribs in the sub-tank are formed with locking corners bent in an L shape in the direction in which the tips face each other, and the lower part of the unit casing has a locking projection on the outer surface. The locking protrusions of the unit casing are slid and locked to the locking corners of the mounting rib. For this reason, when attaching the fuel pump unit to the mounting rib, slide the fuel pump unit from the side of the mounting rib, hold the locking protrusions in the locking corners of the mounting rib, and hold them securely. It is possible to hold the fuel pump unit.

The present invention of claim 6 is a fuel tank in which the lower part of the unit casing is formed to cover the substantially entire bottom surface in the sub tank, and a space is provided between the filter and the lower shell part.

In the present invention of claim 6, the lower part of the unit casing is formed so as to cover substantially the entire bottom surface in the sub-tank, so that the mounting area of the filter can be increased, the resistance of the fuel passing through the filter is reduced, The fuel pump can efficiently deliver fuel.
Further, since the space is provided between the filter and the lower shell portion, the fuel flows smoothly under the filter in the sub tank, and the fuel can be easily sent to the fuel pump via the filter.

The present invention of claim 7 is a fuel tank in which a plurality of filter holding ribs that protrude downward and prevent deformation of the filter are formed on the inner surface of the lower part of the unit casing.

In the present invention of claim 7, since a plurality of filter holding ribs projecting downward and preventing the deformation of the filter are formed on the inner surface of the lower part of the unit casing, when the fuel pump sends out the fuel, the filter is deformed or the unit casing. Contact with the inner surface of the lower portion can be prevented, deformation and tearing of the filter can be prevented, and fuel can be delivered efficiently.

According to the present invention of claim 8, the filter is a fuel tank whose periphery is fixed by a filter case, and the filter case is attached to the lower part of the unit casing.

In the present invention according to claim 8, since the periphery of the filter is fixed by the filter case, and the filter case is attached to the lower part of the unit casing, it is easy to attach and remove the filter to the lower part of the unit casing.

The present invention of claim 9 is a fuel tank in which the periphery of the filter is welded or bonded to the filter case.

In the present invention of claim 9, since the periphery of the filter is welded or bonded to the filter case, it is easy to attach the filter to the filter case, and the filter can be securely fixed to the filter case. By replacing the filter case, the filter can be easily replaced.

The present invention of claim 10 is a fuel tank in which the periphery of the filter is detachably attached to the lower part of the filter case or the unit casing.

In the present invention of claim 10, since the periphery of the filter is detachably attached to the lower part of the filter case or the unit casing, the filter can be easily replaced, and the fuel pump unit can be efficiently inspected and repaired.

In the eleventh aspect of the present invention, the filter is a fuel tank formed of a nonwoven fabric.

In the present invention of claim 11, since the filter is formed of a nonwoven fabric, fuel oil-resistant fibers can be used, dust and the like in the fuel can be efficiently removed, and the filter case and the synthetic fiber A compatible material can be used to weld or adhere to the filter case.

According to a twelfth aspect of the present invention, there is provided a fuel tank in which a unit cover that covers the upper part of the fuel pump is detachably locked to the upper part of the unit casing.

In the present invention of claim 12, since the unit cover that covers the upper part of the fuel pump is detachably locked to the upper part of the unit casing, it is easy to remove and repair and inspect the fuel pump in the unit casing. At the same time, the fuel pump can be reliably held in the unit casing. Further, the unit cover can be provided with a wiring to the fuel pump and a port for attaching a fuel delivery tube, so that the fuel pump unit can be easily attached and detached.

In the present invention of claim 13, 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 13, 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 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.

In the fourteenth aspect of the present invention, the upper shell portion and the lower shell portion are formed by forming the inner resin layer by injection molding of high density polyethylene (HDPE), and the outer surface of the inner resin layer is 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 14, the upper shell portion and the lower shell portion have the inner resin layer formed by injection molding of high density polyethylene (HDPE), so that 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 is put into the tank, the permeation of fuel 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 fuel pump unit for delivering fuel to the sub tank is detachably attached, it can be easily removed when the fuel pump unit is repaired or inspected.
Since the unit casing of the fuel pump unit houses the fuel pump in the upper part of the unit casing, the fuel pump is securely held in the unit casing, and is also reliably held in the fuel tank against vibration during traveling.
The lower part of the unit casing is wider than the upper part of the unit casing so as to have a space, and the filter is detachably attached so as to cover the lower part of the unit casing. Efficiency is good.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a sectional view of a fuel tank 1 to which a fuel pump unit 40 of the present invention is attached. 2 to 5 show a first embodiment of the present invention. FIGS. 2 and 3 are sectional views of a fuel pump unit 40, and FIG. 4 is an assembly and disassembly of the fuel pump unit 40. FIG. FIG. 5 and FIG. 5 are exploded views of attaching the fuel pump unit 40 to the lower shell portion 20. 6 and 7 are exploded views of attaching the fuel pump unit 40 of the second and third embodiments of the present invention to the lower shell portion 20, respectively. FIG. 8 is an exploded view of attaching the filter 52 of the present invention to the filter case 50.

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 sheet that is bonded or welded to the outer side after the inner resin layers 15 and 25 are molded. The outer sheet layers 16 and 26 are composed of 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.

  A sub tank 30 is formed on the inner surface of the lower shell portion 20, and a fuel pump unit 40 is attached in the sub tank 30. The sub tank 30 is provided so that the fuel pump unit 40 can reliably send the fuel in the fuel tank 1 to the engine when the vehicle tilts or vibrates. A pipe extends from the fuel pump unit 40 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. The structures of the sub tank 30 and the fuel pump unit 40 will be described later.

The upper shell portion 10 is integrally formed with a canister 17 that prevents discharge of fuel vapor in the fuel tank 1. An inlet mounting portion 13 and a blister port mounting portion 14 are formed on the upper wall of the canister 17. 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 for releasing the gas in the fuel tank 1 to the outside of the tank when fuel is supplied. A blister hose (not shown) is attached.
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.

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 welded to the front ends of the flange portions 12 and 22, and the fuel-permeable multilayer resin sheet 3 is integrally welded. The outer sheet layers 16 and 26 are configured. The welding 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). Can be firmly joined.

In addition, the upper shell part 10 and the lower shell part 20 can also be formed by only one layer 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 permeation-preventing properties for fuel stored in the fuel tank.

Next, based on FIG. 2 and FIG. 3, the first embodiment will be described focusing on the structure of the sub tank 30 and the fuel pump unit 40.
The sub tank 30 is formed integrally with the lower shell portion 20 when the lower shell portion 20 is molded. A sub-tank outer peripheral wall 31 extends directly from the inner resin layer 25 of the lower shell portion 20 to the outer periphery of the sub-tank 30, and a part of the sub-tank 30 is opened so that the fuel in the fuel tank 1 can flow into the sub-tank 30. ing. A subtank passage wall 35 is formed inside the subtank outer peripheral wall 31 of the opening so as to form a fuel passage.

In the sub tank 30, a fuel pump mounting rib 32 for attaching the fuel pump unit 40 is extended upward from the inner resin layer 25. It is preferable to provide at least four fuel pump mounting ribs 32 in order to stably mount the fuel pump unit 40. A locking rod 36 is formed at the tip of the fuel pump mounting rib 32 to lock the fuel pump unit 40.

The fuel pump unit 40 includes a unit cover 41, a unit casing 47, a fuel pump 43 and a filter case 50.
The unit cover 41 is detachably engaged with the unit casing upper portion 47a, and a fuel tube mounting portion 42 is formed for attaching a fuel tube for transferring fuel delivered from the fuel pump 43 to the engine. Further, a fuel pump socket 42a for supplying electricity for operating the fuel pump 43 is formed. When the unit cover 41 is removed, the fuel pump 43 in the unit casing 47 can be removed for easy repair and inspection.

The unit casing 47 includes a unit casing upper part 47a and a unit casing lower part 47b. The unit casing upper part 47a is formed in a cylindrical shape, and the fuel pump 43 is accommodated therein. For this reason, the fuel pump 43 can be reliably held in the unit casing 47. A fuel inlet 45 is formed at the boundary between the unit casing upper portion 47a and the unit casing lower portion 47b. The front end of the fuel pump 43 is inserted into the fuel suction port 45, and a seal ring 45 b is attached between the fuel suction port 45 and the front end of the fuel pump 43.
A fuel discharge port 44 for discharging fuel is formed at the tip of the fuel pump 43, and the fuel discharge port 44 is connected to the fuel tube mounting portion 42.

The unit casing lower portion 47b is formed so as to have a space by spreading in a flat plate shape in the lateral direction from the unit casing upper portion 47a. A filter 52 is detachably attached to the lower surface of the unit casing lower part 47b.
As shown in FIG. 8, the periphery of the filter 52 is fixed to the filter case 50, and the filter case 50 is attached to the unit casing lower part 47b. For this reason, it is easy to attach and remove the filter 52 to the unit casing lower part 47b.

As shown in FIG. 3, a space is formed between the filter 52 and the inner surface of the inner resin layer 25 of the lower shell portion 20. For this reason, the fuel that has flowed into the sub tank 30 easily flows between the filter 52 and the inner resin layer 25. When the fuel pump 43 sucks the fuel, the fuel is sucked from the entire surface of the filter 52, so the fuel delivery efficiency of the fuel pump 43 is high.

In order to attach the filter 52 to the filter case 50, the periphery of the filter 52 may be welded or bonded to the filter case 50. In this case, it is easy if the filter 52 is a nonwoven fabric made of synthetic fiber, and the filter 52 can be securely fixed to the filter case 50.

Further, the filter 52 can be detachably attached to the filter case 50 or the unit casing lower part 47b. In this case, the filter 52 can be attached by tightening the periphery of the filter 52 to the filter case 50 or the unit casing lower portion 47b with a band or the like. In this case, it is easy to replace the filter 52, and the fuel pump unit 40 can be efficiently inspected and repaired.

In addition, the filter 52 can be formed with a nonwoven fabric. In this case, fuel oil-resistant fibers can be used as the nonwoven fabric, the life of the filter 52 can be extended, and dust and the like in the fuel can be efficiently removed. Further, when the nonwoven fabric is made of a synthetic fiber compatible with the filter case 50, it can be directly welded or bonded to the filter case 50.

A plurality of filter holding ribs 46 that protrude downward and prevent deformation of the filter 52 are formed on the inner surface of the unit casing lower portion 47b. For this reason, when the fuel pump 43 sends out fuel, it can prevent that the filter 52 bends and deform | transforms in the inner surface direction of the unit casing lower part 47b, or contacts the inner surface of the unit casing lower part 47b. Therefore, deformation and breakage of the filter 52 can be prevented.

Further, since the filter 52 is separated from the fuel suction port 45 and a space is formed between the filter 52 and the fuel suction port 45, the filter 52 does not directly block the fuel suction port 45. Therefore, the fuel intake efficiency is good. Also, the area of the filter 52 can be increased, the fuel permeation resistance of the filter 52 can be reduced, and the fuel suction efficiency is better than when the filter 52 is attached to the tip of the fuel inlet 45 of the fuel pump 43. .

Next, a method for assembling the fuel pump unit 40 will be described with reference to FIG. The fuel pump 43 is inserted into the unit casing upper part 47a, and the unit cover 41 is fitted into the unit casing upper part 47a. The lower part of the unit cover 41 and the flange part formed on the upper part of the unit casing upper part 47a are engaged, and the unit cover 41 is detachably attached to the unit casing 47.

Next, the filter case 50 to which the filter 52 is attached is attached to the unit casing lower part 47b. In the filter case 50, filter case mounting portions 51 are provided upright on each of the four sides, and a mounting hole is formed in the filter case mounting portion 51. Filter locking claws 49 protrude from the four sides of the unit casing lower part 47b.
When the filter case 50 is fitted into the unit casing lower portion 47b, the filter locking claw 49 is fitted into the mounting hole of the filter case mounting portion 51, and the filter case 50 is detachably mounted. At this time, the lower end of the fuel pump 43 is inserted into the fuel inlet 45 of the unit casing 47 and sealed by sealing that is a seal member 45b.

The assembled fuel pump unit 40 is locked to the fuel pump mounting rib 32 of the sub tank 30 formed in the lower shell portion 20. A locking rod 36 is formed at the tip of the fuel pump mounting rib 32.
On both outer surfaces of the side surface of the unit casing lower portion 47b, as shown in FIG. 4, two unit locking projections 48 are formed side by side in the lateral direction. The unit locking projection 48 is formed with a locking hole 48a, into which the locking rod 36 at the tip of the fuel pump mounting rib 32 is inserted.

For this reason, the fuel pump unit 40 is moved from the upper side to the lower side of the fuel pump mounting rib 32, and the locking rod 36 at the tip of the fuel pump mounting rib 32 is inserted into the locking hole 48a of the unit locking projection 48. The tip of the fuel pump mounting rib 32 bends and the locking rod 36 engages with the unit locking projection 48, so that the fuel pump unit 40 can be locked securely.

Next, a second embodiment of the present invention will be described with reference to FIG.
The second embodiment is different from the first embodiment in the shape of attaching the fuel pump unit 40 to the sub tank 30, and the other parts are the same. Is omitted.

A fuel pump mounting rib 32 is formed on the inner surface of the sub tank 30, and a locking groove 37 recessed in a U-shape is formed at the tip thereof.
On both outer surfaces of the side surface of the unit casing lower part 47b, two unit locking protrusions 48 are formed in the lateral direction. The unit locking projection 48 is the same in that a locking hole 48a is formed.

For this reason, the fuel pump unit 40 is moved from the upper side to the lower side of the fuel pump mounting rib 32 and is formed outside the locking hole 48a of the unit locking projection 48 of the unit casing 47 in the locking groove 37 of the fuel pump mounting rib. The outer peripheral portion 48b is inserted and locked. For this reason, when the fuel pump unit 40 is attached to the fuel pump mounting rib 32, the fuel pump unit 40 is simply pressed from the upper side to the lower side of the fuel pump mounting rib 32. Thus, the outer peripheral portion 48b of the unit locking projection 48 is fitted, and the fuel pump unit 40 can be reliably held.

Next, a third embodiment of the present invention will be described with reference to FIG.
The third embodiment is different from the first embodiment in the shape of attaching the fuel pump unit 40 to the sub tank 30 and the other parts are the same. Therefore, the different parts are described, and the same parts are described. Is omitted.

Fuel pump mounting ribs 32 are formed on the inner surface of the sub-tank 30, and four fuel pump mounting ribs 32 are formed side by side in parallel. A locking corner portion 38 that is bent so that the ends of the fuel pump mounting rib 32 face each other in an L shape is formed. The unit casing lower portion 47b is formed with a unit locking projection 48 on the outer surface, and the unit locking projection 48 of the unit casing 47 is slid and locked to the locking corner portion 38 of the fuel pump mounting rib 32. . For this reason, when the fuel pump unit 40 is attached to the fuel pump attachment rib 32, the fuel pump unit 40 can be reliably held only by sliding the fuel pump unit 40 from the lateral direction of the fuel pump attachment rib 32.

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 sub tank portion formed integrally with a fuel tank, showing a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a fuel pump unit portion showing a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of a fuel pump unit according to a first embodiment of the present invention. The 1st embodiment of the present invention is shown and it is an assembly exploded view which assembles a fuel pump unit in a sub tank. The 2nd embodiment of the present invention is shown and it is an assembly exploded view which assembles a fuel pump unit in a sub tank. FIG. 10 is an exploded view showing a third embodiment of the present invention, in which a fuel pump unit is assembled in a sub tank. The embodiment of the present invention is shown and it is an assembly exploded view of a filter case. It is a partial exploded side view of the fuel pump unit used for the conventional fuel tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank 10 Upper shell part 20 Lower shell part 30 Sub tank 32 Fuel pump mounting rib 40 Fuel pump unit 41 Unit cover 43 Fuel pump 46 Filter holding rib 47 Unit casing 48 Unit latching protrusion 50 Filter case 52 Filter

Claims (14)

In a fuel tank made of a thermoplastic synthetic resin that is integrally formed by fusing the joint peripheral part of the upper shell part and the lower shell part, which are separately molded by injection molding,
In the lower shell portion, a sub tank is formed integrally with the lower shell portion,
A fuel pump unit for delivering fuel into the sub tank is detachably attached,
The fuel pump unit includes at least a fuel pump and a unit casing. The unit casing houses the fuel pump in an upper part of the unit casing, and the lower part of the unit casing is expanded in a lateral direction from the upper part of the unit casing. A fuel tank, wherein the filter is detachably attached so as to cover the lower part of the unit casing.   2. The fuel tank according to claim 1, wherein a plurality of mounting ribs are erected in the sub tank, and the lower part of the unit casing is locked to the mounting ribs. The mounting rib in the sub-tank is formed with a locking rod at the tip, the side surface of the lower part of the unit casing is formed with a locking projection on the outer surface, and the locking rib of the mounting rib is locked to the locking projection of the unit casing. The fuel tank according to claim 1, wherein the fuel tank is inserted into the locking hole of the portion and locked. The mounting rib in the sub-tank is formed with a locking groove at the tip, the side surface of the lower part of the unit casing is formed with a locking projection on the outer surface, and the locking projection of the unit casing is formed in the locking groove of the mounting rib. The fuel tank according to claim 1, wherein the outer peripheral portion of the locking hole is inserted and locked. The plurality of mounting ribs in the sub-tank are formed with locking corners bent in an L shape in the direction in which the ends face each other, and the unit casing lower part has locking protrusions formed on the outer surface, and the mounting ribs The fuel tank according to claim 1 or 2, wherein a locking projection of the unit casing is slidably engaged with the locking corner of the unit casing. The said unit casing lower part is formed in the area which covers the substantially whole surface of the bottom face in the said sub tank, and provided the space between the said filter and the said lower shell part of any one of Claim 1 thru | or 5. Fuel tank. The fuel tank according to any one of claims 1 to 6, wherein a plurality of filter holding ribs are formed on an inner surface of a lower part of the unit casing so as to protrude downward and prevent deformation of the filter.   The fuel tank according to any one of claims 1 to 7, wherein the filter is fixed around a filter case, and the filter case is attached to a lower portion of the unit casing.   The fuel tank according to claim 8, wherein the periphery of the filter is welded or bonded to the filter case. The fuel tank according to claim 8, wherein the periphery of the filter is detachably attached to the lower part of the filter case or the unit casing. The fuel tank according to any one of claims 1 to 10, wherein the filter is formed of a nonwoven fabric. The fuel tank according to any one of claims 1 to 11, wherein a unit cover that covers an upper portion of the fuel pump is detachably locked to an upper portion of the unit casing. 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 12, 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 12, 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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