JP4299831B2 - Fuel tank - Google Patents

Description

  The present invention relates to a fuel tank whose volume is increased or decreased by being deformed according to the amount of fuel stored.

  In the fuel tank, in order to prevent the fuel vapor generated in the fuel tank from being released into the outside air when the fuel is supplied, the fuel vapor is adsorbed on the activated carbon in the canister. If the amount of fuel vapor generated is large, the capacity of the canister must be increased. In order to reduce the capacity of the canister, it is necessary to reduce the amount of fuel vapor generated as much as possible. Fuel vapor is generated and filled in the upper space of the fuel in the fuel tank. Therefore, in order to reduce the amount of fuel vapor generated, it is necessary to make the volume of the upper space of the fuel in the fuel tank as small as possible.

Therefore, in the fuel tank housing container, a fuel tank partially composed of a stretchable membrane for reducing the upper space and a pump chamber located outside the fuel tank are provided, and the fuel provided in the pump chamber A fuel tank has been proposed in which fuel inside the fuel tank is supplied to the engine by a pump (see, for example, Patent Document 1).
Japanese Patent No. 3362540 (paragraphs 0009 to 0012, FIG. 1)

  However, in the prior art, the pump chamber is provided separately in order not to hinder the increase or decrease in the volume of the fuel tank, so that the fuel pump placed in the pump chamber is disposed away from the center of the fuel tank. Therefore, ensuring the suction performance of the fuel pump is particularly difficult when the fuel tank is tilted. Further, the liquid level gauge is also placed in the pump chamber, but it is disposed away from the center of the fuel tank, and it is particularly difficult to ensure the accuracy of indication when the fuel tank is tilted.

  Therefore, it is conceivable to simplify the structure by storing a fuel pump and a liquid level gauge inside the fuel storage part at least partially made of a flexible membrane. Accordingly, when the volume of the fuel tank is increased or decreased, the fuel tank, the internal fuel pump, and the liquid level gauge may interfere with each other to hinder the function.

  An object of the present invention is to ensure the suction performance of the fuel pump and the indication accuracy of the liquid level gauge in a fuel tank that is at least partially composed of a flexible membrane and whose volume increases or decreases according to the amount of fuel stored. An object of the present invention is to provide a fuel tank that is possible even when the fuel tank is tilted.

  In order to solve the above problems, the present invention provides a fuel tank whose volume is increased or decreased by being deformed according to the amount of fuel stored, a pump chamber for accommodating a fuel pump therein without being deformed according to the amount stored. It has a plurality of variable capacity chambers that are made of a flexible membrane that deforms at least partially according to the amount of storage, and communicate with each other through the pump chamber. According to this, the increase / decrease in the fuel storage amount is absorbed by the volume change of the plurality of variable capacity chambers, and the influence of the increase / decrease in the fuel storage amount can be prevented from affecting the increase / decrease in the volume of the pump chamber. . Therefore, the fuel pump housed in the pump chamber is not easily affected by the increase or decrease in the amount of fuel stored, and the fuel can be reliably supplied. In addition, since multiple variable capacity chambers can be arranged around the pump chamber, equivalently, the pump chamber can be arranged from the center of the fuel tank, ensuring the pumping performance of the fuel pump and the accuracy of indicating the liquid level gauge. However, it is also possible when the fuel tank is tilted.

  In the present invention, it is preferable that the two variable capacity chambers are arranged to face each other with the pump chamber interposed therebetween. According to this, since the pump chamber can be arranged at the center of the fuel tank, it is possible to secure the suction performance of the fuel pump and the indication accuracy of the liquid level gauge even when the fuel tank is tilted.

  In this invention, it is preferable that the pump chamber is provided in the center of the long side direction in the planar view of the fuel tank. This also makes it possible to arrange the pump chamber in the center of the fuel tank.

  In the present invention, it is preferable that a deformation preventing means for suppressing deformation of the pump chamber is provided. According to this, the deformation of the pump chamber can be prevented more reliably. The deformation preventing means preferably includes a housing that suppresses indentation of the upper and lower surfaces of the pump chamber. According to this, deformation of the upper surface and the lower surface of the pump chamber can be prevented more reliably. The deformation preventing means preferably includes a support pipe that suppresses outward swelling of the upper surface and the lower surface of the pump chamber. This also prevents the deformation of the upper and lower surfaces of the pump chamber more reliably. Furthermore, the deformation preventing means preferably includes a support plate that suppresses outward swelling of the lower surface of the pump chamber. This also can prevent the deformation of the lower surface of the pump chamber more reliably.

In the present invention, it is preferable that the pump chamber and the plurality of variable capacity chambers are integrally formed. Even if the fuel tank capacity fluctuates repeatedly due to fuel consumption and filling, the fuel tank has no joints, so that it is difficult for the fuel to leak.
In the present invention, it is preferable to store a liquid level gauge in the pump chamber. According to this, it is possible to accurately detect the fuel level that changes according to the amount of fuel stored.

  In the present invention, it is preferable that the upper surfaces of the plurality of variable capacity chambers are inclined so that the pump chamber side becomes higher. According to this, the fuel vapor collected in the upper part of the plurality of variable capacity chambers can be moved to the pump chamber side and exhausted. In the present invention, it is preferable that the lower surfaces of the plurality of variable capacity chambers are inclined so that the pump chamber side is lowered. According to this, the remaining fuel can be supplied to the pump chamber side to the end.

  According to the present invention, in a fuel tank that is at least partially composed of a flexible membrane and whose volume increases or decreases according to the amount of fuel stored, it is possible to ensure the suction performance of the fuel pump and the accuracy of indication of the liquid level gauge. Further, it is possible to provide a fuel tank that is possible even when the fuel tank is tilted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 4, the fuel tank T according to the embodiment of the present invention includes a fuel storage chamber 2, a pipe frame 5, and a protector 12. The fuel storage chamber 2 has a pump chamber 3, a first variable capacity chamber 13a, and a second variable capacity chamber 13b. The pump chamber 3 accommodates deformation preventing means 25 that suppresses deformation of the pump chamber 3. The pipe frame 5 includes deformation preventing means 38, 52 a, 52 b, 57 a, 57 b that suppress deformation of the pump chamber 3.
The deformation preventing means 25 functions as a housing 25 that constitutes the fuel pump module 24. The deformation preventing means 38 functions as a support plate 38 that supports the pump chamber 3. The deformation preventing means 52 a, 52 b, 57 a, 57 b function as support pipes 52 a, 52 b, 57 a, 57 b that support the pump chamber 3. The support pipes 52a and 52b are made of metal pipes and are provided on the pump chamber 3, the first variable capacity chamber 13a, and the second variable capacity chamber 13b. The support pipes 57a and 57b are made of metal pipes and are provided under the pump chamber 3, the first variable capacity chamber 13a, and the second variable capacity chamber 13b.

  The pump chamber 3, the first variable capacity chamber 13a, and the second variable capacity chamber 13b constitute an integral fuel storage chamber 2 by blow-molding the upper flexible film 14 and the lower flexible film 15 into a bag shape. To do. The pump chamber 3 is partitioned from the first variable capacity chamber 13a by a surface including the support pipes 52a and 57a, and the pump chamber 3 and the first variable capacity chamber 13a communicate with each other. The pump chamber 3 is partitioned from the second variable capacity chamber 13b by the surface including the support pipes 52b and 57b, and the pump chamber 3 and the second variable capacity chamber 13b communicate with each other. . The pump chamber 3 houses a fuel pump module 24 and a fuel supply port 7.

  As shown in FIG. 4, a circular opening 14b is formed in the upper part of the pump chamber 3, and a cap 22 is screwed into a screw 14c formed around the opening 14b. At this time, the disc-shaped cover plate 23 is sandwiched and fixed between the upper surface of the opening 14b and the lower surface of the cap 22 so that the air tightness of the fuel tank T is maintained. A fuel pump module 24 is fixed to the lower surface of the lid plate 23. The fuel pump module 24 includes a housing 25 having an opening 60 in a part thereof, a fuel pump 27 supported inside the housing 25 via a stay 26, and a feed extending from the fuel pump 27 through the cover plate 23 to the outside. A pipe 28, a pressure regulator 29 provided in the middle of the feed pipe 28, a return pipe 30 that discharges excess fuel from the pressure regulator 29 into the pump chamber 3, and a liquid level gauge 31 fixed inside the housing 25. And a float 32 for operating the liquid level gauge 31 following the height of the liquid level of the fuel. Further, a cut valve 33 is provided on the upper surface of the housing 25 to close when the height of the fuel level reaches the upper limit value, and a steam discharge pipe 34 extending from the cut valve 33 is connected to the fuel supply port 7. It is connected in the vicinity of an oil filler opening at the upper end of a filler tube (not shown). Further, the steam discharge pipe 34 is branched and connected to a canister (not shown).

  Since the housing 25 has a size that can pass through the opening 14b, the fuel pump module 24 integrated with the cover plate 23 can be extracted through the opening 14b if the cap 22 is removed, greatly improving the maintainability of the fuel pump module 24. To improve.

  When the fuel is reduced and the volume of the pump chamber 3 is about to decrease, the upper flexible film 14 on the upper surface of the pump chamber 3 tries to go down, and the lower flexible film 15 on the lower surface tries to go up. To do. The so-called upper flexible film 14 and lower flexible film 15 try to indent into the pump chamber 3. The housing 25 suppresses indentation of the pump chamber 3 so that the distance between the upper flexible film 14 and the lower flexible film 15 is constant at the height of the housing 25. For this reason, the bottom surface of the housing 25 is in contact with the lower flexible film 15. Further, the opening 14 b of the upper flexible film 14 is fixed in the vicinity of the periphery of the upper surface of the housing 25. The upper flexible membrane 14 of the pump chamber 3 tends to rise as the fuel increases and the volume of the pump chamber 3 increases, but the upper surface of the housing 25 and the upper flexible membrane 14 are fixed. Therefore, the upper flexible film 14 of the pump chamber 3 is not deformed.

  The lower flexible membrane 15 of the pump chamber 3 also falls down and expands outward from the lower surface of the pump chamber 3 when the fuel increases and the volume of the pump chamber 3 increases. Since the upper surface of 38 is in contact with the lower surface of the lower flexible film 15, the lower flexible film 15 is not deformed and falls down. The support plate 38 is disposed so as to face the lower surface of the housing 25 through the lower flexible film 15, and suppresses outward swelling of the lower surface of the pump chamber 3.

  When the fuel increases and the volume of the pump chamber 3 increases, the upper flexible film 14 on the upper surface of the pump chamber 3 rises and tends to swell outward. The support pipes 52a and 52b are in contact with the upper flexible film 14 to suppress this rise. Further, when the fuel increases and the volume of the pump chamber 3 increases, the lower flexible film 15 on the lower surface of the pump chamber 3 descends and tries to expand outward. The support pipes 57a and 57b are in contact with the lower flexible film 15 to suppress this drop. As described above, the support pipes 52a, 52b, 57a, and 57b suppress the outward swelling of the upper surface and the lower surface of the pump chamber 3. The support pipe 52a and the support pipe 57a are fixed so that the support pipes 52a and 57a uniformly press the upper flexible film 14 and the lower flexible film 15. The support pipe 52a and the support pipe 57a are fixed so that the support pipes 52b and 57b uniformly press the upper flexible film 14 and the lower flexible film 15. Further, the support pipes 52 a, 52 b, 57 a, 57 b are arranged in the vicinity of the fuel pump module 24 so that the upper flexible film 14 and the lower flexible film 15 in the pump chamber 3 are not displaced.

  The support pipes 52a, 52b, 57a, 57b abut on the upper flexible film 14 and the lower flexible film 15, so that the upper flexible film 14 and the lower flexible film 15 have a constricted portion 14a that is recessed in a groove shape. 15a is formed. If the support pipes 52a, 52b, 57a, 57b are fixed so as not to be displaced with respect to the increase / decrease of the fuel, the constricted portions 14a, 15a are not displaced with respect to the increase / decrease of the fuel. It is possible to prevent the interval between the two and the shape of the pump chamber 3 from changing.

  As described above, the pump chamber 3 is not deformed according to the storage amount by the deformation preventing means 25, 38, 52a, 52b, 57a, 57b. Therefore, the fuel pump 27, the liquid level gauge 31, and the cut valve 33 housed therein do not interfere with the upper flexible film 14 and the lower flexible film 15, and the fuel pump 27, the liquid level gauge 31, and the cut There is no possibility that the function of the valve 33 and the like is hindered.

  The first variable capacity chamber 13 a communicates with the pump chamber 3. The first variable capacity chamber 13a includes an upper flexible film 14 and a lower flexible film 15 that are at least partially deformed in accordance with the storage amount. The second variable capacity chamber 13 b also communicates with the pump chamber 3 and communicates with the first variable capacity chamber 13 a through the pump chamber 3. The second variable capacity chamber 13b is separated from the first variable capacity chamber 13a. The second variable capacity chamber 13b is composed of an upper flexible film 14 and a lower flexible film 15 that are at least partially deformed according to the storage amount. When the upper flexible film 14 and the lower flexible film 15 are deformed, the fuel tank T is deformed according to the amount of fuel stored, and the volume is increased or decreased. The first variable capacity chamber 13a and the second variable capacity chamber 13b are arranged so as to face each other with the pump chamber 3 interposed therebetween. The pump chamber 3 is provided at the center in the long side direction of the fuel tank T in plan view. The upper surfaces of the first variable capacity chamber 13a and the second variable capacity chamber 13b including the upper flexible film 14 are inclined so that the pump chamber 3 side becomes higher. The lower surfaces of the first variable capacity chamber 13a and the second variable capacity chamber 13b including the lower flexible film 15 are inclined so that the pump chamber 3 side is lowered.

As shown in FIGS. 1, 2 and 3, the pipe frame 5 includes metal pipe outer peripheral pipes 47 a, 47 b, 48 a and 48 b, in addition to the support pipes 52 a, 52 b, 57 a and 57 b, and metal pipes. The lower support frame 11, the connection portion 62, the support plate 38, and the support plate 61 are included. The outer peripheral pipes 47 a and 47 b protect the outer peripheral portion of the lower surface of the fuel storage chamber 2 together with the protector 12 and the lower support frame 11. The outer peripheral pipe 47a is fixed to the support pipe 57a by welding. The outer peripheral pipe 47b is fixed to the support pipe 57b by welding. The outer peripheral pipes 48 a and 48 b protect the outer peripheral portion of the upper surface of the fuel storage chamber 2. The outer peripheral pipe 48a is fixed to the support pipe 52a by welding. The outer peripheral pipe 48b is fixed to the support pipe 52b by welding. One end of the connecting portion 62 is fixed to the support pipe 52a by welding and the other end is fixed to the support pipe 52b by welding, and the interval between the support pipe 52a and the support pipe 52b is kept constant. Both ends of the support plate 61 are fixed to the lower support frame 11 by welding to form a pedestal for the support plate 38, and the support plate 38 is fixed by adhesion. The lower support frame 11 holds the entire fuel tank T. The protector 12 has a dish-like shape obtained by pressing a metal plate, and protects the fuel storage chamber 2 from the outside. A protector 12, support pipes 57 a and 57 b, outer peripheral pipes 47 a and 47 b, a support plate 61, and a fuel storage chamber 2 are fixed to the lower support frame 11. The outer peripheral pipes 48a and 48b are fixed to the outer peripheral pipes 47a and 47b.
As shown in FIG. 5, the outer peripheral pipes 48 a and 48 b include four mounting brackets 51. The outer peripheral pipes 47 a and 47 b are provided with four mounting brackets 54. The lower support frame 11 includes a plurality of connection portions 56 for fixing the four tank support portions 53, the four mounting brackets 55, the support pipes 57a and 57b, and a plurality of the peripheral pipes 47a and 47b. Connection portions 56. The four mounting brackets 51 of the outer peripheral pipes 48 a and 48 b and the four mounting brackets 54 of the outer peripheral pipes 47 a and 47 b are fastened by bolts 58 and nuts 63. The four mounting brackets 55 of the lower support frame 11 and the protector 12 are fastened by bolts 69 and nuts 59. One end of the connection portion 56 is fixed to the lower support frame 11 by welding, and the other end is fixed to the support pipes 57a and 57b or the outer peripheral pipes 47a and 47b by welding. The bolts 19 and nuts 20 are formed so that the four flanges 16 of the fuel storage chamber 2 are at the heights between the support pipes 52a and 52b and the support pipes 57a and 57b on the four tank support parts 53 of the lower support frame 11. It is concluded with. As described above, the fuel storage chamber 2 is supported between the support pipes 52a and 52b and the support pipes 57a and 57b.

  As shown in FIG. 6, the upper flexible film 14 and the lower flexible film 15 include a polyethylene resin layer 41, a reproduction layer 42, an adhesive layer 43, an ethylene / vinyl alcohol copolymer resin layer 44, from the outside toward the inside. 6 layers of the adhesive layer 45 and the polyethylene layer 46 are laminated in order. The amount of permeated fuel vapor can be minimized by the ethylene / vinyl alcohol copolymer resin layer 44. In the regeneration layer 42, burrs generated in the process of blow molding the fuel storage chamber 2 are reused. Therefore, the reproduction layer 42 includes a polyethylene resin and an ethylene / vinyl alcohol copolymer resin.

  As shown in FIG. 7A, according to the embodiment, the pump chamber 3 is arranged at the center of the fuel tank T, and even when the amount of fuel is small as shown in FIG. The volume of the pump chamber 3 does not fluctuate even when the amount of fuel is large as in (). 7B and 7C are illustrated with emphasis on the vertical direction with respect to FIG. On the other hand, the end positions of the first and second variable capacity chambers 13a and 13b are fixed by the flange 16, and the end surfaces on the pump chamber 3 side are the deformation preventing means 25, 38, 52a, 52b, 57a, 57b. When the amount of fuel is small as shown in FIG. 7B, the upper flexible film 14 on the upper surface is lowered and recessed, and the lower flexible film 15 on the lower surface is raised and recessed. When the amount of fuel is large as shown in FIG. 7C, the upper flexible film 14 on the upper surface rises and expands, and the lower flexible film 15 on the lower surface decreases and expands. According to this, since the volume of the fuel vapor accumulated in the fuel tank T can be made small, even if the capacity of the canister is reduced, it is possible to minimize the diffusion of the fuel vapor to the atmosphere during refueling. it can.

  As shown in FIG. 3, since the height of the flange 16 is arranged to be the height between the support pipes 52a and 52b and the support pipes 57a and 57b, the first and second variable capacity chambers 13a are arranged. And the upper flexible membrane 14 of 13b are inclined so that the pump chamber 3 side becomes higher, and when the fuel is filled from (b) to (c) in FIG. 7, the first and second variable capacity chambers 13a are formed. And the fuel vapor accumulated in the upper part of 13b can be moved to the pump chamber 3 side and reliably discharged from the steam discharge pipe 34.

  Similarly, since the height of the flange 16 is arranged so as to be the height between the support pipes 52a and 52b and the support pipes 57a and 57b, lower portions of the first and second variable capacity chambers 13a and 13b. The flexible membrane 15 is inclined so that the side of the pump chamber 3 is lowered, the fuel decreases from (c) to (b) of FIG. 7, and even if the remaining amount is small, it is supplied to the pump chamber 3 side until the end. The fuel pump 27 can pump up.

  Here, consider a case where the fuel tank T is tilted. For example, it is assumed that the first variable capacity chamber 13a is lower than the second variable capacity chamber 13b. As a result, the fuel in the variable capacity chamber 13 b is emptied, and the corresponding fuel moves to the first variable capacity chamber 13 a and the pump chamber 3. Thus, even if it is inclined, the fuel depth in the pump chamber 3 is not uniformly reduced, and the fuel in the variable capacity chamber 13 b easily flows into the pump chamber 3. Can be kept deep. When the fuel is consumed in this inclined state, the fuel in the first variable capacity chamber 13a moves to the pump chamber 3 due to the inclination of the lower flexible film 15 of the first variable capacity chamber 13a, and the last fuel. Can be used up to. Thus, even when the fuel tank T is inclined, the suction performance of the fuel pump 27 can be ensured. If the liquid level gauge 31 is arranged where the last fuel can be used, the presence or absence of the last fuel can be measured. Therefore, even when the fuel tank T is tilted, the indication accuracy of the liquid level gauge 31 Can be secured.

  Further, by disposing the pump chamber 3 in the center of the fuel tank T, the area of the first variable capacity chamber 13a and the second variable capacity chamber 13b in plan view as shown in FIG. Volume can be secured. This is because the upper flexible film 14 and the lower flexible film 15 are inclined, and the distance between the upper flexible film 14 and the lower flexible film 15 becomes narrower as the distance from the pump chamber 3 increases. This is because more fuel cannot be stored the further away. Therefore, for example, even if the second variable capacity chamber 13b is omitted and the first variable capacity chamber 13a is doubled in the same area in plan view, the volume is only less than twice. Thus, by arranging the pump chamber 3 in the center and arranging a plurality of variable capacity chambers, that is, the first variable capacity chamber 13a and the second variable capacity chamber 13b around the pump chamber 3, a larger amount of the same area can be obtained. Volume can be secured. In addition, when the area of the second variable capacity chamber 13b is omitted and the area of the first variable capacity chamber 13a is doubled, the upper flexible film 14 and the lower flexible film 15 have the same area in plan view. If the inclination of the first variable capacity chamber is relaxed, the volume of the first variable capacity chamber 13a can be doubled, but the ability to supply fuel and fuel vapor to the pump chamber 3 due to the inclination is reduced. On the other hand, according to the embodiment, even if the aspect ratio in plan view is large, the large volume can be secured and the fuel and fuel vapor can be easily supplied with the same area from the plan view as described above. is there.

  Further, since the first and second variable capacity chambers 13a, 13b and the pump chamber 3 are integrally formed, it is possible to contribute to the reduction of the number of parts and the number of assembling steps.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention. For example, although the fuel tank T for automobiles is exemplified in the embodiment, the fuel tank T of the present invention can be applied to a fuel tank for any other purpose.

1 is a perspective view of a fuel tank according to an embodiment of the present invention. It is a top view of the fuel tank concerning an embodiment of the invention. It is the side view which saw through the metal plate 12 of the fuel tank which concerns on embodiment of this invention. FIG. 4 is a cross-sectional view of the fuel pump module of the fuel tank according to the embodiment of the present invention and the vicinity thereof in the IV-IV direction of FIG. 1 is an exploded perspective view of a fuel tank according to an embodiment of the present invention. It is sectional drawing of the flexible membrane of the fuel tank which concerns on embodiment of this invention. (A) is a top view of the fuel tank which concerns on embodiment of this invention, (b) is sectional drawing of the VI-VI direction of (a) of the fuel tank in the state where the capacity | capacitance decreased, ( (c) is sectional drawing of the VI-VI direction of (a) of the fuel tank in the state where the capacity | capacitance increased.

Explanation of symbols

3 Pump chamber 13a, 13b Variable capacity chamber 14, 15 Flexible membrane 25 Housing 27 Fuel pump 31 Liquid level gauge 38 Support plate 52a, 52b Support pipe 57a, 57b Support pipe

Claims (4)

In a fuel tank whose volume increases or decreases by deforming according to the amount of fuel stored,
A pump chamber that houses a fuel pump without being deformed according to the amount of storage;
A fuel tank comprising: a plurality of variable capacity chambers that are formed of a flexible membrane that deforms at least partially according to the amount of storage, and communicate with each other through the pump chamber.   The fuel tank according to claim 1, wherein the two variable capacity chambers are arranged to face each other with the pump chamber interposed therebetween.   3. The fuel tank according to claim 1, wherein the pump chamber is provided at a center in a long side direction in a plan view of the fuel tank.   The fuel tank according to any one of claims 1 to 3, further comprising a deformation preventing unit that suppresses deformation of the pump chamber.

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