JP2008100565A - Fuel tank system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel tank system capable of enhancing pouring property of a fuel at oil-feeding even in the state that an upper fuel tank is fulled and a lower tank does not become in the full state in a constitution provided with a plurality of fuel tanks with different height. <P>SOLUTION: A communication hole 30 for communicating an inner side and an outer side of an inlet pipe 18 is formed near a lower end of the inlet pipe 18. As in the case where a vehicle body is stopped, for example, on an inclined ground or the like, even if a sub-tank 14 becomes relatively a lower side relative to a main tank 16 and temporarily becomes in the full state, when it is returned to the horizontal state, the fuel in the sub-tank 14 is returned from the communication hole 30 to the main tank 16 through the inlet pipe 18 and a connection pipe 26. The full state of the sub-tank 14 is solved in a short time, oil-feeding becomes possible, and the pouring property of the fuel is enhanced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel tank system.

  As a fuel tank system mounted in an automobile, for example, as described in Patent Document 1, there is a fuel tank system provided with a plurality of fuel tanks (dual tank system). In such a fuel tank system, in a configuration in which there is a difference in height between the fuel tanks and the fuel is supplied from the relatively upper fuel tank, it is impossible to supply fuel when the upper fuel tank is full. Composed.

However, in such a fuel tank system, for example, when the vehicle is parked on a sloping ground, the upper fuel tank is full and the lower tank is not full (hereinafter referred to as “ In such a state, the fuel injection property at the time of refueling deteriorates or the refueling cannot be performed.
Japanese Utility Model Laid-Open No. 5-18937

  In the present invention, in consideration of the above facts, in a configuration including a plurality of fuel tanks having different heights, even when the upper fuel tank is full and the lower tank is not full, It is an object of the present invention to obtain a fuel tank system capable of improving fuel injection.

  In the first aspect of the present invention, the first fuel tank in which the fuel is accommodated, the second fuel tank that is disposed below the first fuel tank and in which the fuel is accommodated, and the first fuel tank are provided. An oil supply pipe, a first exhaust pipe for exhausting from the first fuel tank when fueling by the oil supply pipe, and a connection pipe for connecting the first fuel tank and the second fuel tank so that fuel can flow A second exhaust pipe for exhausting the fuel from the second fuel tank to the first fuel tank when the fuel moves from the first fuel tank to the second fuel tank, and from the first fuel tank to the second fuel tank. And a movement promoting means for promoting the movement of the fuel.

  Since this fuel tank system has a plurality of tanks of a first fuel tank and a second fuel tank, more fuel can be accommodated compared to a configuration having only one tank.

  The first fuel tank is provided with a fuel supply pipe, and the first fuel tank and the second fuel tank are connected by a connection pipe. Further, the first fuel tank is disposed above the second fuel tank, and at the time of refueling, fuel is supplied from the fuel supply pipe to the second fuel tank, and further supplied to the first fuel tank through the connection pipe. Further, during refueling, the gas in the second fuel tank is exhausted to the first fuel tank through the second exhaust pipe, and the gas in the first fuel tank is exhausted through the first exhaust pipe.

  When a vehicle equipped with this fuel tank system is stopped on a slope for a long time, for example, the fuel is transferred from the second fuel tank to the first fuel tank, the first fuel tank is temporarily filled, The two fuel tanks may not be full (hereinafter referred to as “non-full state”). In this state, when the vehicle is returned to the horizontal position and refueled, in the present invention, movement of the fuel from the first fuel tank to the second fuel tank is promoted by the movement promoting means. For this reason, in comparison with a configuration in which there is no movement promoting means, that is, a configuration in which the movement of fuel from the first fuel tank to the second fuel tank is not promoted, the temporary full state of the first fuel tank can be reduced in a short time. This can be eliminated and smooth fuel supply to the first fuel tank becomes possible.

  As described above, according to the present invention, even when the relatively upper first fuel tank is full and the lower second fuel tank is not full, the fuel injection performance during refueling can be improved.

  According to a second aspect of the present invention, in the first aspect of the present invention, the movement promoting means is formed in a portion of the connection pipe located in the first fuel tank and communicates the inside and the outside of the connection pipe. It is the communicating hole which is characterized by the above-mentioned.

  Therefore, the fuel in the first fuel tank flows into the connection pipe from the communication hole and moves to the second fuel tank. The movement promoting means can be configured with a simple structure in which only the communication hole is provided.

  According to a third aspect of the invention, in the first aspect of the invention, a part of the fuel supply pipe on the first fuel tank side also serves as a part of the connection pipe.

  Thus, the structure can be simplified by sharing a part of the oil supply pipe with the connection pipe.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the fuel supply pipe is provided with a backflow restricting means for restricting a backflow of fuel.

  This backflow prevention means can prevent backflow of fuel from the first fuel tank to the fuel supply pipe. In the configuration in which a part of the first fuel tank side of the fuel supply pipe also serves as the connection pipe, the movement of the fuel from the first fuel tank to the second fuel tank is promoted even if the backflow prevention means is provided. Promoted by means. That is, the present invention is preferably applied to a configuration in which a part of the fuel supply pipe on the first fuel tank side also serves as a connection pipe and is provided with backflow prevention means.

  Since the present invention is configured as described above, in a configuration including a plurality of fuel tanks having different heights, even when the upper fuel tank is full and the lower tank is not full, The fuel injection property can be improved.

  FIG. 1 shows a fuel tank system 12 according to a first embodiment of the present invention. This fuel tank system 12 has two fuel tanks, a sub tank 14 and a main tank 16 disposed below the sub tank. Thereby, more fuel can be accommodated compared with the structure which has only one fuel tank. In particular, even if it is difficult or impossible to arrange a single large-capacity tank due to a limited fuel tank installation space, such as under the floor of an automobile, by dividing the fuel tank into two, Large capacity is possible.

  The lower portion of the inlet pipe 18 passes through the upper surface of the sub tank 14, and the lower end of the inlet pipe 18 is opened in the sub tank 14. The inlet pipe 18 is provided with an oil supply port 20, which can be supplied with an oil gun (not shown).

  The lower part of the first breather pipe 22 passes through the upper surface of the sub tank 14. The lower end of the first breather pipe 22 is opened without the sub tank 14 so as to be positioned above the lower end of the inlet pipe 18. An upper end of the first breather pipe 22 is connected to an intermediate portion of the inlet pipe 18. Therefore, when the fuel is supplied from the inlet pipe 18 into the sub tank 14, the gas in the sub tank 14 escapes from the sub tank 14 through the first breather pipe 22 so that the fuel supply is not hindered. When the liquid level of the fuel in the sub-tank 14 reaches the lower end of the first breather pipe 22, the fuel tank is full and gas cannot escape. Is stopped. In other words, in the present embodiment, when the sub tank 14 is in a full tank state, the fuel cannot be supplied.

  As shown in detail in FIG. 2, a check valve 24 is provided at the lower end of the inlet pipe 18. The check valve 24 allows the fuel to move from the inlet pipe 18 into the sub tank 14, but prevents or restricts the movement in the opposite direction. The check valve 24 prevents backflow or leakage of fuel due to pressure fluctuation or liquid level fluctuation in the sub tank 14.

  As shown in FIG. 1, a connection pipe 26 is provided between the inlet pipe 18 and the main tank 16. The lower portion of the connection pipe 26 passes through the upper surface of the main tank 16 (the corner portion at the boundary between the upper surface and the side surface in FIG. 1), and one end (lower end) of the main pipe 16 is opened in the main tank 16. The other end (upper end) of the connection pipe 26 is connected to the inlet pipe 18 at a position below the connection position of the first breather pipe 22 and above the upper surface of the sub tank 14. Since a part of the inlet pipe 18 also serves as a part of the connection pipe 26 that connects the sub tank 14 and the main tank 16, the inlet pipe 18 and the connection pipe 26 are completely separated from each other. The structure is simplified.

  A second breather pipe 22 is provided between the inlet pipe 18 and the main tank 16. The lower part of the second breather pipe 22 penetrates the upper surface of the main tank 16, and one end (lower end) thereof is opened in the main tank 16. The other end of the second breather pipe 22 passes through the upper surface of the sub tank 14, and the other end is opened in the sub tank 14.

  When a part of the fuel supplied by the inlet pipe 18 flows into the main tank 16 through the connection pipe 26, the gas in the main tank 16 escapes into the sub tank 14 through the second breather pipe 22, The fuel supply to the main tank 16 is not hindered.

  As shown in FIG. 2, a communication hole 30 that connects the inside and the outside of the inlet pipe 18 is formed on the peripheral surface of the inlet pipe 18 and in the vicinity of the lower end. In consideration of the viscosity of the fuel, the communication hole 30 is formed with an opening area that allows the fuel to move smoothly through the communication hole 30.

  Next, the operation of the fuel tank system 12 of this embodiment will be described.

  When supplying fuel to the fuel tank system 12, a fuel gun (not shown) is connected to the fuel supply port 20 to send fuel. This fuel flows into the main tank 16 through the inlet pipe 18 and also into the sub tank 14 through the connection pipe 26, as indicated by an arrow F1 in FIG. At this time, the gas in the main tank 16 escapes to the sub tank 14 by the second breather pipe 22 and further the gas in the sub tank 14 escapes to the outside by the first breather pipe 22 as shown by an arrow E1 in FIG. Refueling is not hindered. Then, the fuel level in the sub tank 14 rises, reaches the lower end of the first breather pipe 22, and can continue to supply fuel until the sub tank 14 is full.

  Here, as shown in FIG. 3, a case is considered in which the state where the sub tank 14 is relatively lower than the main tank 16 continues for a long time, for example, when the vehicle body is stopped on an inclined ground or the like. At this time, even if the sub tank 14 is not full, the fuel in the main tank 16 moves into the sub tank 14 through the connection pipe 26 and the inlet pipe 18 as indicated by the arrow F2 in FIG. ) Moves to the main tank 16 as indicated by the arrow E2), the sub tank 14 temporarily becomes full (the main tank 16 becomes non-full).

  Next, when the fuel tank system 12 is refueled, the vehicle is generally in a horizontal state as shown in FIG. In the present embodiment, since the communication hole 30 is formed near the lower end of the inlet pipe 18, the fuel in the sub-tank 14 passes through the inlet pipe 18 from the communication hole 30 as shown by an arrow F3 in FIG. Return to the main tank 16 via the connection pipe 26. At this time, the gas in the main tank 16 moves to the sub tank 14 as indicated by an arrow E3.

  Here, FIG. 5 and FIG. 6 show a fuel tank system of a comparative example. The configuration of the comparative example is the same as that of the first embodiment of the present invention except that the communication hole 30 is not formed in the inlet pipe 18.

  If the communication hole 30 is not formed in the inlet pipe 18 as in the configuration of this comparative example, the fuel in the sub tank 14 flows from the opening at the lower end of the inlet pipe 18 through the inlet pipe 18 and the connecting pipe 26 to the main tank 16. However, since the check valve 24 is provided at the lower end of the inlet pipe 18, it takes a long time to transfer the fuel from the sub tank 14 to the main tank 16. On the other hand, in this embodiment, since the communication hole 30 is formed in the inlet pipe 18 in the vicinity of the lower end, the fuel in the sub tank 14 passes from the communication hole 30 through the inlet pipe 18 and the connection pipe 26 to the main tank 16. Return in a short time.

  Thereby, the full tank state of the sub-tank 14 is also eliminated in a short time, allowing fuel supply, and fuel injection performance is improved.

  FIG. 7 shows a fuel tank system 42 according to the second embodiment of the present invention. In the second embodiment, compared to the first embodiment, only the configuration of the movement promoting means according to the present invention is different. Therefore, in the following, the same components, members, etc. as in the first embodiment are denoted by the same reference numerals. The detailed description is omitted.

  In the second embodiment, the communication hole 30 according to the first embodiment is not formed. Instead, a sub pipe 44 that connects the sub tank 14 and the main tank 16 along the connection pipe 26 from the inlet pipe 18 is provided. Is provided. One end of the sub pipe 44 opens into the main tank 16 at the same position as one end of the connection pipe 26. Further, as shown in detail in FIG. 8, the other end of the sub pipe 44 opens into the sub tank 14 at a position substantially the same as the position where the communication hole 30 of the first embodiment is formed.

  In the second embodiment having such a configuration, the fuel is returned (returned) from the full tank sub tank 14 to the main tank to the non-full tank state through the sub pipe 44. Therefore, as in the first embodiment, the full tank state of the sub-tank 14 can also be eliminated in a short time, enabling refueling and improving the fuel injection performance.

  As described above, the movement promoting means of the present invention is not limited to the communication hole 30 formed in the inlet pipe 18, and the movement promoting means is provided by promoting the fuel transfer from the sub tank 14 to the main tank 16. What is necessary is just to make it transfer in a short time compared with the structure which is not.

  In the above description, the configuration having two fuel tanks (the sub tank 14 and the main tank 16) is taken as an example, but the present invention can also be applied to a configuration having three or more fuel tanks.

1 is a partially cutaway front view showing a schematic configuration of a fuel tank system according to a first embodiment of the present invention. It is explanatory drawing which expands and shows the lower end vicinity of an inlet pipe in the fuel tank system of 1st embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a schematic configuration of a fuel tank system according to a first embodiment of the present invention in a partially broken state with a vehicle tilted. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a schematic configuration of a fuel tank system according to a first embodiment of the present invention in a partially broken state in a state in which the fuel tank system is horizontal after tilting. It is a front view which partially fractures and shows schematic structure of the fuel tank system of a comparative example. It is explanatory drawing which expands and shows the lower end vicinity of an inlet pipe in the fuel tank system of a comparative example. It is a front view which partially fractures and shows schematic structure of the fuel tank system of 2nd embodiment of this invention. It is explanatory drawing which expands and shows the lower end vicinity of an inlet pipe in the fuel tank system of 2nd embodiment of this invention.

Explanation of symbols

12 Fuel tank system 14 Sub tank (first fuel tank)
16 Main tank (second fuel tank)
18 Inlet pipe (oil supply piping)
20 Refueling port 22 First breather pipe (first exhaust pipe)
24 Check valve (reverse flow restricting means)
26 Connection pipe (connection piping)
28 Second breather pipe (second exhaust pipe)
30 communication hole (movement promotion means)
42 Fuel tank system 44 Sub-pipe (movement promotion means)

Claims (4)

A first fuel tank in which fuel is stored;
A second fuel tank disposed below the first fuel tank and containing fuel;
Refueling piping provided in the first fuel tank;
A first exhaust pipe for exhausting from the first fuel tank when refueling by the oil supply pipe;
A connection pipe for connecting the first fuel tank and the second fuel tank so that the fuel can flow;
A second exhaust pipe for exhausting from the second fuel tank to the first fuel tank when the fuel moves from the first fuel tank to the second fuel tank;
A movement promoting means for promoting movement of fuel from the first fuel tank to the second fuel tank;
A fuel tank system comprising:   2. The fuel according to claim 1, wherein the movement promoting means is a communication hole that is formed in a portion of the connection pipe located in the first fuel tank and communicates the inside and the outside of the connection pipe. Tank system.   The fuel tank system according to claim 1 or 2, wherein a part of the fuel supply pipe on the first fuel tank side also serves as a part of the connection pipe.   The fuel tank system according to claim 3, wherein the fuel supply pipe is provided with a backflow restricting means for restricting a backflow of fuel.

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