MXPA00002293A

MXPA00002293A - Fuel reservoir

Info

Publication number: MXPA00002293A
Application number: MXPA/A/2000/002293A
Authority: MX
Inventors: Yoshihiko Hyodo; Takaaki Itoh; Takashi Ishikawa; Masahide Kobayashi; Kidokoro Tooru
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 1998-03-26
Filing date: 2000-03-06
Publication date: 2002-05-09

Abstract

A fuel reservoir for storing a fuel, provided with a wall which divides the inner space of the reservoir into a fuel chamber and an air chamber and is variable in shape depending upon the amount of fuel in the fuel chamber, a discharge passage opened to a space formed above a fuel liquid surface in the fuel chamber, and a shut-off valve for normally shutting off the discharge passage. When the shut-off valve is opened, a gas is discharged from the space through the discharge passage. If the amount of the gas is greater than a predetermined amount, the shut-off valve is opened so as to discharge the gas out of the space. On the other hand, if the amount of the gas is less than the predetermined amount, the shut-off valve is closed to stop discharge of the gas.

Description

"A FUEL RESERVE DEVICE" BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The invention relates to a fuel reserve device and, in particular, a fuel tank connected to a motor. 2. DESCRIPTION OF THE RELATED TECHNIQUE A fuel reserve device or fuel tank must be in communication with the outside air in such a way that the surface of the fuel can rise and fall into the fuel tank. In the fuel tank, the fuel vapor can be generated in a space formed above the surface of the fuel. Therefore, the problem of the discharge of fuel vapor from the fuel tank to the outside air arises. In a prior art, a fuel tank is in communication with the outside air through a charcoal can to temporarily adsorb the fuel vapor therein. The charcoal canister should be large if the amount of fuel vapor generated in the fuel tank is large. To solve this problem, Japanese Unexamined Patent Publication Number 64-16426 discloses a fuel tank comprising therein an inflatable air bag, the air bag being inflated or deflated according to the load of the level of the surface of the fuel to prevent a space from forming above the surface of the fuel in the fuel tank. However, in the fuel tank disclosed in the aforementioned publication, the interior of the fuel tank does not remain in communication with the outside air. Therefore, if a space has not already formed above the fuel surface, the space can not be removed when the airbag is inflated. In this way, the fuel vapor can be generated in space above the fuel surface. Therefore, the object of the invention is to eliminate the space above the surface of the fuel and the fuel vapor therein, from the fuel reserve device.

SUMMARY OF THE INVENTION In accordance with the invention, a fuel reserve device is provided for reserving fuel therein comprising: a wall for dividing an interior of the device into a fuel chamber and an air chamber, the wall according to the amount of fuel in the fuel chamber; a discharge passage leading to a space formed above the fuel surface in the fuel chamber; a shut-off valve for normally closing the discharge passage; a gas discharge means for discharging the gas from the space through the discharge passage when the shut-off valve is open; and a control means for controlling the gas discharge means and the shut-off valve to open the shut-off valve and operate the gas discharge means to discharge the gas from the space when the amount of the gas is larger than one. predetermined amount, the control means closing the shut-off valve and stopping the operation of the gas discharge means to stop the gas discharge operation when the amount of the gas is smaller than the predetermined amount. Further, in accordance with the invention, the fuel surface level detecting means is provided to detect the level of the surface of the fuel in the fuel chamber, and the control means judges that the amount of the gas is larger than the predetermined amount, when the level of the fuel surface detected by the fuel surface level detecting means is less than a predetermined level. Further, in accordance with the invention, a means is provided for raising the level of surface to raise the level of the fuel surface, and the gas discharge means controls the means for raising the level of fuel surface in order to lift the level of the fuel surface to discharge the gas from the space when the amount of gas is larger than the predetermined amount. Likewise, according to the invention, the means for raising the level of the surface of the fuel feeds the fuel to the fuel chamber to raise the level of the fuel surface. Also in accordance with the invention, the means for raising the level of the fuel surface deforms the wall to raise the level of the fuel surface.

Furthermore, according to the invention, the means for raising the level of fuel surface increases the pressure in the air chamber to deform the wall. Also, according to the invention, the means for raising the level of the fuel surface increases the pressure in the air chamber to a pressure lower than that of the fuel fed to the fuel chamber when the fuel supply is stopped. the fuel chamber. Further, in accordance with the invention, the means for raising the fuel surface level decreases the pressure in the air chamber when the fuel supply to the fuel chamber is stopped. Also, in accordance with the invention, the means for raising the level of the fuel surface introduces a negative pressure in the space to deform the wall. Further, in accordance with the invention, the means for raising the level of the fuel surface comprises a fuel pump for pumping the fuel in order to generate a negative pressure by the pumped fuel, and introduces the negative pressure in the space through of the download passage.

Also, in accordance with the invention, the means for raising the level of the fuel surface returns to a portion of the fuel pumped by the fuel pump into the fuel chamber in order to generate the negative pressure. Furthermore, according to the invention, the fuel pump is housed in a pump chamber connected to the fuel chamber, the means for raising the level of the fuel surface returns the portion of the fuel pumped by the fuel pump to the pump chamber in order to generate the negative pressure and introduce the negative pressure into a space formed above the surface of the fuel in the pump chamber. Furthermore, in accordance with the invention, the discharge passage is connected to an air intake system of an engine, and the means for raising the level of the fuel surface introduces the negative pressure in the air intake system towards the space formed above the surface of the fuel through the discharge passage. In addition, according to the invention, the discharge passage is connected to the air intake system through a canister to adsorb the fuel vapor therein, and the canister comprises a valve that opens into the atmosphere when the pressure in the can is under a predetermined negative pressure to cause the canister to communicate with the atmosphere. Further, in accordance with the invention, the means for raising the level of the fuel surface raises the level of the fuel surface when the engine can receive the fuel vapor. The present invention can also be more fully understood from the description of the preferred embodiments of the invention which will be pointed out below, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 is a sectional view of a fuel reserve device according to the first embodiment of the invention; Figure 2 is a sectional view of the fuel reserve device along line II-II of Figure 1; Figure 3 is a sectional view of the fuel reserve device immediately after the supply of fuel to the fuel chamber stops; Figure 4 is a sectional view of the fuel reserve device when the fuel in the fuel chamber is decreased; Figure 5 is a sectional view of a fuel reserve device according to the second embodiment of the invention; Figure 6 is a flow chart of an operation to remove the vapor from the fuel according to the second embodiment of the invention; Figure 7 is a sectional view of a fuel reserve device according to the third embodiment of the invention; Figure 8 is a flow chart of an operation to remove the vapor from the fuel according to the third embodiment of the invention; Figure 9 is a sectional view of a fuel reserve device according to the fourth embodiment of the invention; Figure 10 is a flow chart of an operation to remove the vapor from the fuel in accordance with the fourth embodiment of the invention; Figure 11 is a sectional view of a fuel reserve device according to the fifth embodiment of the invention; Figure 12 is a flow chart of an operation to remove the vapor from the fuel according to the fifth embodiment of the invention; Figure 13 is a sectional view of a fuel reserve device according to the sixth embodiment of the invention; Figure 14 is a sectional view of a fuel reserve device, in accordance with the seventh embodiment of the invention; Figure 15 is a flow chart of the operation to remove the vapor from the fuel according to the seventh embodiment of the invention; Figure 16 is a sectional view of a fuel reserve device according to the eighth embodiment of the invention; Figure 17 is a flow chart of an operation for removing the vapor from the fuel in accordance with the eighth embodiment of the invention; Figure 18 is a sectional view of a fuel reserve device according to the ninth embodiment of the invention; Figure 19 is a flow chart of an operation to remove the vapor from the fuel in accordance with the ninth embodiment of the invention; Figure 20 is a sectional view of a fuel reserve device according to the tenth embodiment of the invention; Figure 21 is a part of a flow chart of an operation for removing steam from the fuel in accordance with the tenth embodiment of the invention; Figure 22 is a part of a flow chart of the operation for removing steam from the fuel in accordance with the tenth embodiment of the invention; Figure 23 is a sectional view of a fuel reserve device according to the eleventh embodiment of the invention; Figure 24 is a sectional view of a fuel reserve device according to the thirteenth embodiment of the invention; Figure 25 is a sectional view of a fuel reserve device according to the thirteenth embodiment of the invention; Figure 26 is a part of a flow chart of an operation for removing the vapor from the fuel according to the thirteenth embodiment of the invention; Figure 27 is a part of a flow chart of an operation for removing the vapor from the fuel according to the thirteenth embodiment of the invention; Figure 28 is a partial sectional view of a fuel reserve device, in accordance with the fourteenth embodiment of the invention; Figure 29 is a perspective view of the fuel tank according to the fourteenth embodiment of the invention; Figure 30 is a perspective view of the fuel tank in the expanded state; Figure 31 is a perspective view of the fuel tank in the deflated state; Figure 32 is a partial sectional view of a fuel pump device according to the fourteenth embodiment of the invention; Figure 33 is a partial sectional view of the fuel pump device on line XXXIII-XXXIII in Figure 32; Figure 34 is a partial sectional view of another fuel pump device different from that according to the fourteenth embodiment of the invention; Figure 35 is a partial sectional view of a fuel pump device according to the fifteenth embodiment of the invention; and Figure 36 is a partial sectional view of the fuel pump device on line XXXVI-XXXVI in Figure 35.

DESCRIPTION OF THE PREFERRED MODALITIES A fuel reserve device according to the first embodiment of the invention will be explained below. For example, the fuel reserve device is mounted on a vehicle to reserve the fuel to be fed to an engine. However, the fuel reserve device can be used to reserve fuel just for a certain period. As shown in Figure 1, a fuel tank 1 of the fuel reserve device comprises upper and lower portions 2 and 3 consisting of a material such as metal or a synthetic resin. The upper and lower portions 2 and 3 are sealingly connected to one another in the peripheral flange portions 2a and 3a thereof. A wall or separating sheet 5 is placed inside an interior 4 defined by the upper and lower portions 2 and 3. The wall 5 separates the interior 4 in an air chamber 6 placed above the wall 5, and a chamber 5 fuel 7 placed under the wall 5. The wall 5 is made of a material having flexibility and vapor impermeability such as polyethylene or nylon. The wall 5 is fixed to an anchor portion 8 in a peripheral portion 5a thereof. That is, the wall 5 is sealably fixed to one side of the inner wall of the fuel tank 1. The peripheral portion 5a of the wall 5 is stapled between the peripheral flange portions 2a and 3a of the upper and lower portions 2 and 3 The wall 5 comprises annular bent portions 5b therein which are generally arranged concentrically and are equally spaced apart from one another. Therefore, the wall 5 has a wave-shaped portion defined by the folded annular portions 5b. The wall 5 can be bent in the bent portions 5b. Therefore, a central portion 5c of the wall 5 can move up and down in the tank 1. In this manner, the partition wall 5 deforms in the folded portion 5b where the central portion 5c moves upwards and down. A fuel supply pipe 13 is sealingly connected to the lower portion 3, and is open towards the interior of the fuel chamber 7. A cover 14 for closing the pipe 13 is detachably fixed in the upper opening 13a of the pipe 13. A seal member 15 contacting an outer peripheral face of the lid 14 when the lid 14 is fixed in the opening 13a, a seal member 16 that comes into contact with an outer peripheral face of a filling nozzle of fuel when the nozzle is inserted into the pipe 13 to fill the fuel chamber 7 with fuel, and a fuel vapor shut-off valve 17 which normally closes the pipe 13 by a spring force, is provided in the adjacent pipe 13 to opening 13a. On the other hand, a check valve 10 is provided in a lower opening 13b of the fuel supply pipe 13. The valve 10 is opened by the pressure of the fuel supplied from the fuel filler nozzle, which is closed by the fuel pressure in the fuel chamber 7. A fuel pump chamber 18 is connected to the fuel chamber 7. The fuel pump chamber 18 is defined by the lower portion 3 and projects outwardly from the peripheral flange portion 2a of the upper portion 2. A fuel pump 19, a pressure regulator 20 and a fuel filter 21 are placed in the fuel pump chamber 18. The pressure of the fuel pumped by the pump 19 is regulated by the regulator 20, and then, the fuel is fed to the fuel injectors (not shown) through a feed pipe of 22. It is not necessary to provide any of the fuel return passages returning to the fuel to the fuel tank 1 from a fuel distribution pipe to distribute the fuel from the fuel supply pipe 22 to each injector, since the regulator 20 returns the fuel to the fuel pump chamber 18 connected to the fuel chamber 7. At therefore, the fuel, which is heated adjacent to a cylinder head of the engine and which includes the same fuel vapor, is not returned to the fuel chamber 7. In this way, the generation of the fuel vapor in the fuel chamber 7 is prevented. Moreover, the transmission of the noise from the pump 19 from the fuel tank 1 to the exterior of the tank 1 is prevented since the pump 19 is placed in the tank of fuel 1. The fuel chamber 7 is connected to the fuel supply pipe 13 through a circulation pipe 23. The pipe 23 connects to the lower portion 3, and opens into the fuel chamber 7 above the lower opening 13b of the fuel supply pipe 13, and immediately below the anchor portion 8. The pipeline circulation 23 releases the air from the fuel chamber 7 to the fuel supply line 13 when the fuel is supplied to the fuel chamber 7 through the fuel supply line 13. Therefore, the fuel supply towards the fuel chamber 7 is carried out easily. A first check valve 30 is fixed to an opening in the circulation pipe 23 that opens towards the interior of the fuel chamber 7. The valve 30 is closed by the fuel reaching the valve 30. Therefore, when the valve 30 is closed, the pressure in the fuel supply pipe 13 adjacent to the opening of the circulation pipe 23 leading to the inside the fuel supply pipe 13, it is of course reduced. An upper space 18a in the fuel pump chamber 18 is in communication with the interior of the fuel supply pipe 13 through a fuel vapor discharge pipe 24. The pipe 24 is connected with a portion of the top wall which defines the fuel pump chamber 18. The pipe 24 releases air from the fuel chamber 7 to the fuel supply pipe 13, when fuel is supplied to the fuel chamber 7 through the fuel supply pipe. fuel 13. Therefore, the fuel supply to the fuel chamber 7 is easily carried out. A second shut-off valve 31 is fixed to an opening of the fuel vapor discharge pipe 24 which opens into the fuel pump chamber 18. The valve 31 is closed by the fuel reaching the valve 31. Therefore, when the valve 31 is closed, the pressure in the fuel supply pipe 13 adjacent to the opening of the fuel vapor discharge pipe 24, which is open towards the interior of the fuel supply pipe 13 , It decreases. The opening of the fuel vapor discharge pipe 24 which is open towards the interior of the fuel supply pipe 13, is positioned above the opening of the circulation pipe 23 which is open inside the pipe 13 of fuel supply. The fuel supply line 13 is connected to a charcoal can 26 through a first fuel vapor purge line 25. One Li The opening of the pipe 25 opening into the interior of the fuel supply pipe 13 is positioned at the level equal to the opening of the discharge pipe 24 of the fuel vapor that is open towards the interior of the fuel supply pipe 13 . The charcoal can 26 comprises a char 26a activated therein to adsorb the fuel vapor thereon. The can 26 is open to the outside air through an atmosphere relief pipe 28. In addition, the canister 26 is connected to an intake passage (not shown) of the engine through a second fuel vapor purge line 27. The fuel vapor generated in the fuel chamber 7, the fuel supply pipe 13 and the fuel pump chamber 18 is introduced into the charcoal can 26 through the circulation pipe 23, the discharge pipe 24 of steam from the fuel and the first pipe 25 for purging the fuel vapor and is adsorbed on the activated coal 26a. Therefore, the discharge of fuel vapor into the outside air is prevented. The vapor of the fuel adsorbed on the activated carbon 26a is vented to the intake passage through the second steam venting pipe 27 of the fuel on the basis of a motor driving condition, such as a motor load. For example, the separation wall 5 is moved, by the movement of the fuel in the fuel chamber 7, when the vehicle is connected to the fuel tank 1. Therefore, a large load such as a stress is generated in the wall 5. In the first embodiment, as shown in Figure 2, one side of the inner wall of a side wall 3b of the lower portion 3 is tilted towards in from the anchor portion 8 to a wall 3c of the bottom of the lower portion 3. The shape of the face of the inner wall of the side wall 3b corresponds to the shape of the wave-shaped portion defined by the bent portions 5b when the central portion 5c is placed in the lower area in the fuel chamber 7. Therefore, the horizontal and vertical movement of the waveform portion of the wall 5, and the movement of the wall 5 are prevented, regardless of the position of the central portion 5c of the wall 5 in the fuel chamber 7 . Annular projections 29 are formed on the face of the inner wall of the side wall 3b of the lower portion 3b. The projections 29 project inward from the side wall 3b so that the side wall 3b has steps therein. The waveform portion including the bent portions 5b is uniformly brought into contact with the projections 29. Therefore, the horizontal and vertical movement of the waveform portion of the wall 5, and the movement of the wall 5, they are prevented of course. The projections 29 are formed on the side wall 3b from the anchor portion 8 to the bottom portion 3c so that recesses are formed between the adjacent projections 29. The recesses retain the bent portions 5b so that the horizontal and vertical movement of the wave-shaped portion of the wall 5, and the movement of the wall 5, are further prevented. As described above, the generation of the large stress in the wall 5 is prevented so that the damage of the wall 5 is prevented. In addition, the projections 29 decrease the volume of air formed between the surface of the combusible and the wall 5 to decrease the amount of fuel vapor generated in the fuel chamber 7. Also, the projections 29 reinforce the lower portion 3 so that there is no need to provide any reinforcing member to reinforce the lower portion 3. The springs 32 as the pushing or resilient means are fixed to one face of the inner wall of the upper portion 2 of the fuel tank 1. The springs 32 extend downward from the face of the inner wall of the upper portion 2. The springs 32 abut against the central portion 5c of the wall 5., when the central portion 5c moves upwards. Therefore, the stop of the wall 5 on the face of the inner wall of the upper portion 2 is of course prevented. The air chamber 6 is in communication with the outside air through the pipe 33 that flows into the atmosphere. The pipe 33 is connected to the upper portion 2 of the fuel tank 1. The pipe 33 releases air from the air chamber 6 to the outside air when the central portion 5c of the wall 5 moves upwardly. Therefore, the central portion 5c moves easily upward when the fuel is supplied to the 7 fuel chamber. On the other hand, the pipe 33 introduces the air into the air outside the air chamber 6, when the central portion 5c of the wall 5 moves downwardly. Therefore, the central portion 5c moves easily downwards when the Fuel in the fuel chamber 7 is used during engine driving. An operation of removing the fuel vapor from the space above the fuel surface in the fuel chamber 7, ie, the space between the fuel surface in the fuel chamber and the wall 5 (hereinafter referred to to this as the "operation to remove the fuel vapor") in accordance with the first embodiment of the invention, will be explained below. In the first embodiment, when there is a space above the fuel surface in the fuel chamber 7, the fuel is supplied to the fuel chamber 7. The level of the fuel surface is raised by the supply of fuel to the fuel chamber 7. Therefore, the fuel vapor in the passage above the fuel surface is discharged therefrom to the fuel supply pipe 13 through the pipes 23 and 24 for the circulation and discharge of the fuel vapor. The fuel chamber 7 is sealed when the fuel surface reaches the first and second closing valves 30 and 31, that is, when the fuel vapor in the space above the fuel surface is completely removed therefrom. Then, the fuel supply to the fuel chamber 7 stops. Once the fuel chamber 7 is sealed, the sealing of the fuel chamber 7 is maintained so that spaces can not be formed above the fuel surface in the fuel chamber 7. In this way, the generation of fuel vapor in the fuel chamber 7 is prevented. Therefore, generation of the fuel vapor in the fuel chamber 7 is prevented. In the first embodiment, the supply of fuel to the fuel chamber 7 corresponds to the means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface. The operation of removing the vapor from the fuel according to the first embodiment will be explained below with reference to the Figures. Figure 1 shows the fuel tank 1 that includes the fuel vapor in it. Before starting the supply of fuel to the fuel chamber 7, the lid 14 is removed from the upper opening 13a of the fuel supply pipe 13. When the lid 14 is removed, the fuel vapor shut-off valve 17 closes. Therefore, the discharge of the fuel vapor from the upper opening 13a into the outside air is prevented. Then, a fuel filler nozzle (not shown) is inserted into the upper opening 13a of the fuel feed pipe 13. The nozzle opens the fuel vapor lock valve 17 against the thrust force and then the outer peripheral face of the nozzle contacts the seal member 16.

Therefore, when the nozzle is inserted into the fuel supply line 13, the discharge of the fuel vapor from the upper opening 13a towards the outside air is prevented. Next, fuel is supplied from the nozzle to the fuel chamber 7 through the fuel supply line 13. The level of the fuel surface in the fuel chamber 7 rises as the amount of fuel in the fuel chamber 7 increases. Therefore, the wall 5 moves upwards. When the level of the fuel surface rises, the fuel vapor in the space above the fuel surface is discharged from the fuel chamber 7 to the fuel supply pipe 13 through the pipes 23 and 24 of the fuel pipe. circulation and discharge of fuel vapor. The wall 5 is maintained in sealing contact with the fuel surface when the level of the fuel surface is raised. Therefore, the amount of fuel vapor generated in the fuel chamber 7 when the fuel is supplied theris kept small. The first shut-off valve 30 is closed by the fuel in the fuel chamber 7 to close the circulation pipe 23 when the fuel surface reaches the valve 30. Next, the upward movement of the central portion 5c of the wall 5 It is restricted by the springs 32. Then, as shown in Figure 3, the second closing valve 31 is closed by the fuel in the fuel chamber 7 to close the steam discharge line 24 when the surface of the fuel reaches the valve 31. Therefore, the fuel vapor in the space above the fuel surface is completely removed from the fuel chamber 7 and the fuel tank 1. The pressure in the fuel supply pipe 13 is decreased to less than a predetermined pressure when the first and second closing valves 30 and 31 are closed. When the pressure sensor in the nozzle detects that the decreased pressure is less than the predetermined pressure, the fuel supply to the fuel chamber 7 stops. Then, the fuel pressure in the fuel chamber 7 becomes higher than that of the fuel in the fuel supply line 13. Therefore, the closing valve 10 is closed by the fuel in the fuel chamber 7. In this way, the fuel chamber 7 is completely sealed while there is no fuel vapor in the fuel chamber 7.

- - Next, the nozzle is withdrawn from the upper opening 13a of the fuel supply pipe 13, and then, the fuel vapor shut-off valve 17 is closed by the force of the spring. Finally, the lid 14 is fixed to the upper berth 13a of the fuel supply pipe 13. An operation of the fuel tank 1 during the driving of the engine according to the first mode, will be explained below. During the driving of the engine, the amount of fuel in the fuel chamber 7 is decreased. Therefore, the level of the fuel surface in the fuel chamber 7 is decreased and the central portion 5c of the wall 5 moves downward. As shown in Figure 4, the wall 5 projects downward towards the fuel chamber 7. When the wall 5 moves downward, since the fuel chamber 7 is sealed, no spaces can be formed above the surface of the fuel. Therefore, once the operation to remove the fuel vapor is carried out, generation of the fuel vapor in the fuel chamber 7 is prevented. In this way, only a small or no amount of the charcoal canister should be provided in the fuel reserve device.

In the first embodiment, the first and second closing valves 30 and 31 can be opened when the fuel moves in the fuel chamber 7. Therefore, a space above the surface of the fuel can be formed in the fuel chamber 7, and fuel vapor can be generated therein even when the engine is driven. Therefore, in accordance with the second embodiment, the fuel vapor is removed by a method other than the supply of the fuel to the fuel chamber 7. A fuel reserve device according to the second embodiment of the invention will be explained below. In the second embodiment, as shown in Figure 5, an air pump 35 is connected to the air chamber 6 through a first connection pipe 34 instead of the atmosphere pipe 33 of the first mode. The pump 35 serves to increase the pressure in the air chamber 6. The first connection pipe 34 is connected to a relief valve 37 through a second connection pipe 36. The valve 37 opens to decrease the pressure in the air chamber 6 when the pressure in the air chamber 6 becomes higher than a predetermined pressure. The predetermined pressure is lower than that which can damage the wall 5. A small hole 39 is formed in a diaphragm 38 of the relief valve 37. The hole 39 places the second connection pipe 36 in communication with the outside air, independently of the opening or closing of the relief valve 37. The diameter of the hole 39 is positioned so as not to prevent the air pump 35 from increasing the pressure in the air chamber 6. A level switch 57 is mounted on the upper wall of the fuel pump chamber 18 and the highest position on the fuel tank 1. The switch 57 sends a voltage when the fuel surface reaches the switch 57, that is, when the fuel surface reaches the highest position in the fuel tank 1. The fuel reserve device comprises an electronic control unit 40. The unit 40 is a digital computer and is provided with a CPU (microprocessor) 42, a RAM (random access memory) 43, and a ROM (read only memory) 44, a B-RAM (backup RAM) 45, an inlet orifice 46 and an outlet orifice 47, which are interconnected by a bidirectional bus 41.

A voltage generated in the level switch 57 when the fuel surface reaches the switch 57 is admitted into the inlet orifice 46 through a corresponding AD converter 48. A voltage representing the opening or closing of the relief valve 37 is admitted into the inlet orifice 46 through a corresponding AD converter 48. The outlet orifice 47 is connected to the air pump 35 through a driving circuit 49. The components other than those described above are the same as those in the fuel reserve device according to the first embodiment. Therefore, an explanation of them will not be provided. An operation to remove the vapor from the fuel according to the second embodiment will be explained below. In the second embodiment, it is judged whether the relief valve 37 is open. When the relief valve 37 is closed, it is judged that the pressure in the air chamber 6 allows the operation to remove the vapor from the fuel. In addition, in the second embodiment, it is judged whether the level switch 57 is connected. When the level switch 57 is turned off, it is judged that the operation to remove the fuel vapor must be carried out. When it is judged that the relief valve 37 is closed and the level switch 57 is turned off, the air pump 35 is activated to increase the pressure in the air chamber 6. Therefore, the central portion 5c of the wall 5 moves down to the bottom wall 3c in the lower portion 3. In this way, the level of the fuel surface that forms a space above rises. When the level of the fuel surface rises, the fuel vapor is discharged from the fuel chamber 7 to the fuel supply pipe 13 through the pipes 23 and 24 for circulation and discharge of the fuel vapor. When it is judged that the pressure in the air chamber 6 does not allow the operation to eliminate fuel vapor, the air pump 35 is stopped. In the second embodiment, the air pump 35 corresponds to the means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface, and the level switch 57 corresponds to the means for detecting the surface of the fuel. The operation for removing the fuel vapor according to the second embodiment will be explained below with reference to a flow chart in Figure 6. In step 210, it is judged whether the level switch 57 is connected. When connected to switch 57, it is judged that the operation to remove the fuel vapor can not be carried out, the routine proceeds to step 212 where the air pump 35 is stopped, and the routine is terminated. On the other hand, when the switch 57 is turned off, it is judged that the vapor removal operation of the fuel can be carried out and the routine proceeds to step 214. In step 214, it is judged whether the relief valve 37 is open . When the valve 37 is open, it is judged that the operation to remove the fuel vapor can not be carried out, the routine proceeds to step 212 where the air pump 35 is stopped and the routine is terminated. On the other hand, when the valve 37 is closed, it is judged that the operation to remove the vapor from the fuel must be carried out, the routine proceeds to step 216 where the air pump 35 is activated to increase the pressure in the chamber 6. of air to remove the fuel vapor from the fuel chamber 7, and the routine is terminated. In the first mode, in order to completely remove the fuel vapor from the fuel tank, it is necessary to fill the fuel tank with fuel until the tank is filled with fuel. Therefore, if the fuel supply to the fuel chamber 7 is stopped before the tank with the fuel is full, the fuel vapor can not be completely removed from the fuel chamber 7. In the third embodiment, even when the supply of fuel to the fuel chamber is stopped before the fuel chamber is filled with fuel, the fuel vapor is completely removed from the fuel chamber. A fuel reserve device according to the third embodiment of the invention will be explained below. In the third embodiment, as shown in Figure 7, the fuel tank 1 comprises a lid closing-opening switch 50. The opening switch 50 is connected with a lid lock (not shown) to cover the lid 14. The opening switch 50 is activated to send a voltage when the lid closure is opened, and continues to send the voltage until it closes the lid closure. Therefore, it can be judged that the fuel is now supplied by detecting the voltage in the opening switch 50. The voltage generated in the opening switch 50 is admitted in the input hole 46 through a corresponding AD converter 48. The components other than those described above are the same as those of the fuel reserve device according to the second embodiment.

Therefore, an explanation of them will not be provided. An operation to remove the fuel vapor according to the third embodiment will be explained below. In the third embodiment, it is judged whether the relief valve 37 is open. When the valve 37 is closed, it is judged that the pressure in the air chamber 6 allows the operation to eliminate fuel vapor. In addition to judging whether the lid closing-opening switch 50 is connected and whether the level switch 57 is disconnected. When the opening switch 50 is turned on and the level switch 57 is turned off, it is judged that the operation to remove the steam from the fuel must be carried out. When the pressure in the air chamber 6 does not allow the operation of removing the vapor from the fuel and does not need to carry out the vapor elimination operation of the fuel, the opening of the closure of the lid is allowed to start the supply of the fuel towards the fuel chamber 7. On the other hand, when the pressure in the air chamber 6 allows the operation of eliminating fuel vapor, and the operation of eliminating the fuel vapor must be carried out, the air pump 35 is activated to increase the pressure in the 6 air camera. Therefore, the central portion 5c of the wall 5 moves downwards. In this way, the fuel vapor above the fuel surface is discharged from the tank 1 to the fuel supply pipe 13, through the pipes 23 and 24 for circulating and discharging the fuel vapor. Then, when the pressure in the air chamber 6 does not allow the steam removal operation of the fuel, or when the operation of eliminating the fuel vapor does not need to be carried out, the air pump stops and the opening of the closure the fuel supply to the fuel chamber 7 is allowed to start from the lid. Therefore, the air pump 35 corresponds to the means for discharging the gas from the space above the fuel surface or for raising the level of the fuel surface, and the level switch 57 corresponds to the means for detecting the level of the surface of the fuel. According to the third embodiment, when the fuel supply is started to the fuel chamber 7, the level of the fuel surface rises to the highest level. Therefore, the amount of the fuel to be supplied to raise the level of the fuel surface to the highest level in the fuel chamber 7 is smaller than that in the first mode. Thus, in accordance with the third embodiment, the fuel vapor can be completely removed from the fuel chamber 7 even when the fuel supply to the fuel chamber 7 stops before the fuel chamber is filled with the fuel . Note that the fuel feed nozzle used to feed the fuel into the fuel chamber in the third mode stops the fuel supply when the nozzle detects that the fuel level in the fuel feed pipe 13 exceeds a predetermined level. The predetermined level is lower than the opening of the circulation pipe 23 that opens into the fuel supply pipe 13.

The operation for removing the fuel vapor according to the third embodiment will be explained below, referring to a flow chart in Figure 8. In step 310, it is judged whether the lid opening-closing switch 50 is connected. . When the opening switch 50 is turned on, the routine proceeds to step 312. On the other hand, when the opening switch 50 is turned off, the routine proceeds to step 318 where the air pump 35 is stopped, and the routine is terminated. In step 312, it is judged whether the level switch 57 is connected. When the level switch 57 is connected, it is judged that no operation to remove the fuel vapor needs to be carried out, the routine proceeds to step 314, where the air pump 35 is stopped, the routine proceeds to step 316 in where the opening of the lid closure is allowed, and the routine is terminated. On the other hand, when the level switch 57 is off, the routine proceeds to step 320. In step 320, it is judged whether the relief valve 37 is open. When the valve 37 is open, it is judged that the operation to remove the fuel vapor can not be carried out, the routine proceeds to step 314 where the air pump 35 stops, the routine proceeds to step 316 where the opening the closure of the lid is allowed, and the routine is terminated. On the other hand, when the valve 37 is closed, it is judged that the operation to remove the fuel vapor can be carried out, the routine proceeds to step 322 where the air pump 35 is activated to increase the pressure in the chamber air 6, and the routine is terminated. In the second embodiment, the air pump 35 and the relief valve 37 are used to carry out the operation to eliminate steam from the fuel. Therefore, the structure of the fuel reserve device is complicated and the cost for manufacturing the fuel reserve device is increased. According to the fourth embodiment, the operation is carried out to eliminate the vapor of the fuel with a simpler structure. A fuel reserve device according to the fourth embodiment will be explained below. In the fourth mode, as shown in Figure 9, the air pump 35, the relief valve 37 and the first and second connecting pipes 34 and 36 of the second embodiment are suppressed, and a pipe 33 of the atmosphere connects with the upper portion 2 of the tank 1 of gas.

The charcoal can 26 of the second embodiment is omitted, and an electromagnetic valve 51 is connected to the first and second fuel vapor purge lines 25 and 27. The fuel supply pipe 13 is connected to the intake passage 52 through the first and second fuel vapor purge lines 25 and 27 and the electromagnetic valve 51. The electromagnetic valve 51 closes the communication between the fuel supply pipe 13 and the intake passage 52. The fuel reserve device comprises a temperature sensor 55 for generating a voltage corresponding to the temperature of the cooling water to cool the engine. The temperature sensor 55 is connected to the inlet port 46 through a corresponding AD 48 converter. The outlet orifice 47 is connected to the electromagnetic valve 51 through the driving circuit 49. Other components than those described above are the same as those of the fuel reserve device according to the second embodiment. Therefore, an explanation of them will not be provided.

An operation for eliminating steam from the fuel according to the fourth embodiment will be explained below. In the fourth embodiment, it is judged whether the temperature of the cooling water is higher than a predetermined temperature (for example 70 ° C). The predetermined temperature is higher than that of the cooling water when the cooling water cools the motor in the constant driving condition. When the temperature of the cooling air is higher than the predetermined temperature, the driving condition of the engine allows the operation to remove the vapor from the fuel. Furthermore, in the fourth embodiment, it is judged that the level switch 57 is connected. When the switch 57 is disconnected, it is judged that the operation to remove the fuel vapor must be carried out. When the driving condition of the engine allows the operation of eliminating fuel vapor, and the operation of eliminating the fuel vapor must be carried out, the electromagnetic valve 51 opens to introduce the negative pressure in the intake passage 52 to the chamber of fuel 7. The negative pressure introduced discharges the fuel vapor from the fuel chamber 7, moves the central portion 5c of the wall 5 downwards, and raises the level of the fuel surface. When the driving condition of the engine does not allow the operation to eliminate the vapor from the fuel, or when the steam removal operation of the fuel does not need to be carried out, the electromagnetic valve 51 is closed. Therefore, in accordance with the fourth embodiment, the simplest structure of the fuel reserve device without the air pump and the relief valve can remove the fuel vapor from the fuel chamber. In the fourth embodiment, the purging of the fuel vapor from the fuel chamber to the intake passage corresponds to the means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface and the level switch 57 corresponds to the means for detecting the level of the fuel surface. Further, in the fourth embodiment, the operation to remove the fuel vapor can be controlled on the basis of the engine speed, or the engine load, or the amount of air introduced into the combustion chambers of the engine, the condition of the combustion in the combustion chambers. For example, when the engine speed or the engine load or the amount of air introduced into the combustion chambers is less than a predetermined value, or when the combustion is in the stratified condition, the operation is stopped to remove the fuel vapor. The operation to remove the fuel vapor according to the fourth embodiment will be explained below with reference to a flow chart in Figure 10. In step 410, it is judged whether the level switch 57 is connected. When the switch 57 is connected, it is judged that no steam vapor removal operation needs to be carried out, the routine proceeds to step 412 where the electromagnetic valve 51 is closed, and the routine is terminated. On the other hand, when the switch 57 is turned off, the routine proceeds to step 414. In step 414, it is judged whether the temperature T of the cooling water is higher than the predetermined temperature TO (T >; TO). When T > To, it is judged that the driving condition of the engine allows the steam removal operation of the fuel, the routine proceeds to step 416 where the electromagnetic valve 51 is opened and the routine is terminated. On the other hand, when T < TO, the driving condition of the engine does not allow the steam removal operation of the fuel, the routine proceeds to step 412 where the electromagnetic valve 51 is closed, and the routine is terminated. In the fourth embodiment, in the event that a charcoal canister is to be provided to the fuel reserve device, the canister can be provided in the first fuel vapor purge line 25 between the fuel supply line 13 and the valve 51 electromagnetic. The can can be in communication with the outside air to avoid an excessive decrease in the pressure in the canister when the electromagnetic valve 51 is opened, and to avoid an excess of increase in pressure in the fuel chamber 7 when the valve is closed 51 electromagnetic. Therefore, in the event that a fuel reserve device according to the fourth embodiment comprises a charcoal can, the negative pressure can not be introduced into the fuel chamber 7 due to the communication of the can with the air outside so that the fuel vapor in the fuel chamber 7 can not be removed. According to the fifth embodiment, the negative pressure can be introduced into the fuel chamber 7 even when the fuel reserve device comprises a can of charcoal.

A fuel reserve device according to the fifth embodiment of the invention will be explained below. In the fifth embodiment, as shown in Figure 11, a charcoal can 26 is provided in the first fuel vapor purge line 25 between the fuel supply line 13 and the electromagnetic valve 51. The can 26 is in communication with the outside air through an atmosphere relief pipe 28. A control valve 58 for closing the atmosphere relief pipe 28 is provided in the pipe 28. The valve 58 is constituted by positive and negative valves. In addition, the valve 58 opens at a predetermined positive pressure to decrease the pressure in the can 26, and closes at a predetermined negative pressure to increase the pressure in the can 26. The predetermined positive pressure is lower than those that can withstand the fuel tank 1, the charcoal can 26, the components related thereto and the wall 5, or the fuel vapor can not be discharged from the tank 1, the can 26 or the components related thereto. The predetermined negative pressure is higher than that which the fuel tank 1, the charcoal can 26, the components related thereto and the wall 5 can withstand. The components other than those described above are the same as those described above. those of the fuel reserve device according to the fourth embodiment.

Therefore no explanation of them will be provided. An operation to remove the fuel vapor according to the fifth embodiment will be explained below. In the fifth embodiment, it is judged whether the temperature of the cooling water is higher than the predetermined temperature. When the temperature of the cooling water is higher than the predetermined temperature, it is judged that the temperature of the cooling water allows the operation to remove the steam from the fuel. The predetermined temperature is higher than that of the cooling water when the cooling water cools the motor in the constant driving condition. Furthermore, in the fifth embodiment, it is judged whether the level switch 57 is connected. When the level switch 57 is disconnected it is judged that the operation to remove the fuel vapor must be carried out.

When it is judged that the temperature of the cooling water permits the operation of eliminating fuel vapor, and the operation of removing steam from the fuel must be carried out, the electromagnetic valve 51 is opened to introduce the negative pressure in the passage 52 of admission to the can 26 through the second pipe 27 for purging the fuel vapor. When the negative pressure is introduced into the can 26, the pressure in the can 26 is lower than the predetermined positive pressure and is higher than the predetermined negative pressure due to the action of the control valve 58. Of course, when the pressure in the can 26 is lower than the predetermined negative pressure, the control valve 58 is opened and the negative pressure lower than the predetermined negative pressure can not be introduced into the fuel chamber 7, i.e. only the negative pressure higher than the predetermined negative pressure can be introduced into the fuel chamber 7. Therefore, the negative pressure in the intake passage 52 is introduced into the fuel chamber 7 through the first fuel vapor purge line 25, the circulation line 23 and the fuel vapor discharge line 24. . Thus, in accordance with the fifth embodiment, the fuel tank with the charcoal can, the negative pressure in the intake passage can be introduced into the fuel chamber 7 in order to eliminate the vapor of the fuel above the surface of the fuel. In the fifth modality, purging the fuel vapor from the fuel chamber to the intake passage corresponds to the means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface, and the switch 57 level corresponds to the medium to detect the level of the fuel surface. When it is judged that the temperature of the cooling water does not allow the steam removal operation of the fuel, or the preliminary operation of the fuel vapor can not be carried out, the electromagnetic valve 51 is closed. The fuel vapor removal operation according to the fifth embodiment will be explained below with reference to a flow chart in Figure 12. In step 510, it is judged whether the level switch 57 is connected. When the level switch 57 is connected, it is judged that a fuel vapor removal operation need not be carried out, the routine proceeds to step 514 where the electromagnetic valve 51 is closed and the routine is terminated. On the other hand, when the level switch 57 is disconnected, it is judged that the operation to remove the steam from the fuel must be carried out, and the routine proceeds to step 516. In step 516, it is judged whether the temperature T of the water of cooling is higher than the predetermined temperature TO (T >; TO). When T > TO, the cooling water temperature does not allow the operation to remove the fuel vapor, the routine proceeds to step 514 where the electromagnetic valve 51 is closed and the routine is terminated. On the other hand, when T < TO, the cooling water temperature allows operation to remove the fuel vapor, the routine proceeds to step 518 where the electromagnetic valve 51 is opened to introduce negative pressure into the fuel chamber 7, and the routine is given by finished In the third embodiment, the pressure in the air chamber 6 is maintained at a pressure at which the relief valve 37 is opened when the air pump is activated. After the air pump 35 is stopped, the pressure in the air chamber 6 is released through the hole 39 of the relief valve 37 and maintained at atmospheric pressure.

A certain time period of time is required until the pressure in the air chamber 6 is sufficiently released by means of the hole 39, since the hole 39 is small to prevent a sudden decrease in the pressure in the air chamber 6 by the air pump 35. Therefore, the fuel can not flow into the fuel chamber 7 through the fuel filler nozzle if the pressure in the air chamber 6 is too high. According to the sixth embodiment, fuel can flow into the fuel chamber 7 through the fuel filler nozzle even after the pressure in the air chamber 6 is increased. A fuel reserve device according to the sixth embodiment of the invention will be explained below. In the sixth embodiment, as shown in Figure 13, a second relief valve 59 is connected to the second connection pipe 36. The second relief valve 59 opens to release the pressure from the air chamber 6 when the pressure in the air chamber 6 is higher than a second predetermined pressure. The second predetermined pressure is lower than the fuel pressure when the fuel is supplied through the fuel filler nozzle. The amount of air released from the second relief valve 59 is smaller than that pumped by the air pump 35, and is larger than that which flows through the hole 39 of the relief valve 37. The components other than those described above are the same as those of the fuel reserve device in accordance with the third embodiment. Therefore, an explanation of them will not be provided. An operation to eliminate the fuel vapor according to the sixth embodiment will be explained below. The operation of eliminating fuel vapor according to the sixth embodiment is carried out in the same manner as the third mode. Furthermore, in the same manner as in the third embodiment, the air pump 35 is stopped when the level switch 57 is connected or the relief valve 37 is opened. In the sixth embodiment, when the pressure in the air chamber 6 is higher than the second predetermined pressure after the air pump 35 is stopped, the second relief valve 59 is opened. Therefore, the pressure in the air chamber 6 becomes lower than the fuel pressure when the fuel is supplied by the fuel filler nozzle before the third mode. In this way, fuel can flow into the fuel chamber 7 through the fuel filler nozzle. Furthermore, in accordance with the sixth embodiment, the rate of increase of the pressure in the air chamber is less than that in the third mode when the pressure is within the range between the opening pressure of the second relief valve 59 in the opening pressure of the relief valve 37. A flow chart of the sixth modality is the same as that of the third modality. Therefore, an explanation of it will not be provided. In the sixth embodiment, the pressure in the air chamber 6 is increased by the air pump 35 with the pressure in the air chamber 6 having been released by the second relief valve 59 when the pressure in the air chamber 6 is more higher than the second predetermined pressure. Therefore, the regime of the increase in pressure in the air chamber 6 in the sixth embodiment is lower than that in the third embodiment that does not comprise any second relief valve. In this way, in the sixth mode, a period of time is permitted from when the opening switch 50 is connected until when the opening of the closing valve is longer than that in the third mode. According to the seventh embodiment, fuel can flow into the fuel chamber 7 through the fuel filler nozzle even after the pressure in the air chamber 6 is increased, and the regime of the increase in pressure in the air chamber becomes larger than that in the sixth mode. A fuel reserve device according to the seventh embodiment of the invention will be explained below. In the seventh embodiment, as shown in Figure 14, an electro-magnetic valve 60, instead of the first and second relief valves 37 and 59, is connected to the second connection pipe 36. The electromagnetic valve 60 is connected to the outlet orifice 47 through a corresponding driving circuit 49 and is controlled by the electronic control unit 40. The electromagnetic valve 60 closes the communication between the air chamber 6 and the outside air. A pressure sensor 61 for detecting the pressure in the air chamber 6 is mounted in the upper portion 2 of the tank 1. The sensor 61 is connected to the inlet port 46 through a corresponding AD converter 48.

The components other than those described above are the same as those of the fuel reseating device in accordance with the sixth embodiment. Therefore, an explanation of them will not be provided. An operation to remove the fuel vapor according to the seventh embodiment will be explained below. In the seventh embodiment, it is judged whether the pressure in the air chamber 6 is lower than a maximum predetermined pressure. The maximum predetermined pressure is lower than that at which the wall 55 can be damaged by pressure in the air chamber 6. When the pressure in the air chamber 6 is lower than the maximum predetermined pressure, it is judged that the condition of the engine and the fuel tank 1 allows the operation to remove the vapor from the fuel. Furthermore, in the seventh embodiment, it is judged whether the lid closing-opening switch 50 and the level switch 57 are connected. When the lid closing-opening switch 50 is connected and the level switch 57 is turned off, it is judged that the operation to remove the vapor from the fuel should be carried out. Furthermore, in the seventh embodiment, it is judged whether the pressure in the air chamber 6 is lower than a second predetermined pressure. The second predetermined pressure is lower than the fuel pressure when fuel is supplied through the fuel filler nozzle. When the pressure in the air chamber 6 is lower than the second predetermined pressure, it is judged that the pressure in the air chamber 6 allows the closure of the lid to open. When the condition of the engine and the fuel tank 1 allows the operation to eliminate the fuel vapor, if the operation of removing the fuel vapor must be carried out, the electromagnetic valve 60 is closed and the air pump 35 is activated to increase the pressure in the air chamber 6. Therefore, the fuel vapor above the fuel surface is discharged from the fuel chamber 7 through the pipes 23 and 24 for circulating and discharging the fuel vapor. According to the seventh embodiment, the regime of the increase in pressure in the air chamber 6 is greater than that in the sixth mode. When no operation is required to remove the fuel vapor, the air pump 35 is stopped, the electromagnetic valve 60 is opened to lower the pressure in the air chamber 6 than the second predetermined pressure, and the opening of the closure of the lid.

When the condition of the engine and the fuel tank 1 does not allow the steam removal operation of the fuel, the air pump 35 is stopped and the electromagnetic valve 60 is opened to make the pressure in the air chamber 6 lower than the maximum predetermined pressure. In the seventh embodiment, the air pump 35 corresponds to a means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface, and the level switch 57 corresponds to the means for detect the level of the fuel surface. The operation for removing the vapor from the fuel according to the seventh embodiment will be explained below with reference to a flow chart in Figure 15. In step 710, it is judged whether the closure-opening switch 50 of the lid is connected. When the switch 50 is turned on, the routine proceeds to step 712. On the other hand, when the switch 50 is turned off, that is, when the fuel supply to the fuel chamber 7 is completed, the routine proceeds to step 722 where the electromagnetic valve 60 is closed to maintain the pressure in the relatively high air chamber 6, the routine proceeds to step 724 where the air pump 35 is stopped, the routine proceeds to step 726 where a supply flag of gas, and the routine is terminated. The fuel supply flag is graduated when it is judged that the pressure in the air chamber 6 does not allow the operation of eliminating fuel vapor and is readjusted when the fuel supply to the fuel chamber is compelled. In step 712, it is judged whether the level switch 57 is connected. When the switch 57 is connected, it is judged that an operation to remove the fuel vapor need not be carried out, the routine proceeds to step 742 where the air pump 35 is stopped, the routine proceeds to step 744 where it is opened the electromagnetic valve 60 to make the pressure in the air chamber 6 lower than the second predetermined pressure, the routine proceeds to step 746 where the closing of the lid is allowed and the routine is terminated. On the other hand, in step 712, when the level switch 57 is turned off, it is judged that the operation to remove the steam from the fuel must be carried out, and the routine proceeds to step 714. In step 714, it is judged whether the pressure P in the air chamber 6 is lower than the maximum predetermined pressure Pmax (P <; Pmax). When P Pmax, the routine advances to step 716. On the other hand, when P > Pmax, it is judged that the pressure in the air chamber 6 does not allow the vapor removal operation of the fuel since the pressure in the air chamber 6 is already higher than the maximum predetermined pressure, the routine proceeds to step 728 in where the fuel supply flag is adjusted, the routine proceeds to step 730 where the electromagnetic valve 60 is opened to decrease the pressure in the air chamber 6, and the routine proceeds to step 732. In step 716, it is judged if the fuel supply flag is readjusted. When the flag is readjusted, it is judged that the pressure in the air chamber 6 allows the operation to eliminate fuel vapor, the routine proceeds to step 718 where the electromagnetic valve 60 is closed, the routine proceeds to step 720 where the air pump 35 is activated and the routine is terminated. On the other hand, when the fuel supply flag is adjusted, it is judged that the pressure in the air chamber 6 does not allow the fuel vapor removal operation and the routine goes to step 732. In step 732, it is judged if the pressure P in the air chamber 6 is lower than the second predetermined pressure P2 (P <P2). When P < P2, it is judged that the pressure in the air chamber 6 allows the supply of fuel to the fuel chamber 7, the routine proceeds to step 734 where the electromagnetic valve 60 is closed, the routine proceeds to step 736 where the pump 35 of air is activated to maintain the pressure in the relatively high air chamber 6 during the supply of fuel to the fuel chamber 7, the routine proceeds to step 738 where opening of the lid closure is allowed, and the routine is It is finished. On the other hand, when P < P2, it is judged, that the pressure in the air chamber 6 does not allow the supply of fuel in the fuel chamber 7. The routine proceeds to step 739 where the air pump 35 is stopped, the routine proceeds to step 740 where the electromagnetic valve 60 is opened and the routine is terminated. In the second embodiment, the fuel can move in the fuel chamber when the rate of increase in pressure in the air chamber is large. Therefore, the first and second shut-off valves can be opened so that the fuel can enter the circulation and discharge pipes of fuel vapor. According to the eighth embodiment, the inclination of the increase in pressure in the air chamber becomes smaller than that at which the fuel can move greatly in the fuel chamber. A fuel reserve device according to the eighth embodiment, will be explained below. In the eighth embodiment, as shown in Figure 16, an electromagnetic valve 60 instead of the relief valve 37 in the second embodiment is connected to the second connection pipe 36. The valve 60 is connected to the outlet orifice 47 through a corresponding driving circuit 49, and is controlled by the electronic control unit 40. The valve 60 disconnects the communication between the air chamber 6 and the outside air. A pressure sensor 61 for detecting the pressure in the air chamber 6 is mounted in the upper portion 2 of the tank 1. The sensor 61 is connected to the inlet port 46 through a corresponding AD converter 48. A fuel level gauge 62 for detecting the amount of fuel in the fuel chamber 7 by detecting the position of the wall 5, is mounted in the upper portion 2 of the tank 1. The gauge 62 connects with the inlet orifice 46 to through a corresponding AD converter 48.

The fuel reserve device comprises a temperature sensor 55 for generating a voltage corresponding to the temperature of the cooling water to cool the engine. The temperature sensor 55 is connected to the inlet port 46 through a corresponding AD converter 48. The components other than those described above are the same as those of the fuel reserve device according to the second embodiment. Therefore, an explanation of them will not be provided. A fuel vapor removal operation according to the eighth embodiment will be explained below. In the eighth embodiment, it is judged whether the temperature of the cooling water is higher than a predetermined temperature and the amount of fuel in the fuel chamber 7 is greater than a predetermined amount of the fuel. The predetermined temperature is higher than that of the cooling water when the cooling water cools the engine in the constant driving condition, and the predetermined amount of the fuel is greater than that sufficient to raise the level of the fuel surface to the highest level. elevated in the fuel chamber 7, when the partition wall 5 moves downwards. When the temperature of the cooling water is higher than a predetermined temperature and the amount of fuel in the fuel chamber 7 is larger than a predetermined amount of the fuel, it is judged that the conditions of the engine and of the fuel tank 1 allow the operation to eliminate steam from fuel. Furthermore, in the eighth mode it is judged whether the level switch 57 is switched off. When the level switch 57 is turned off, it is judged that the fuel vapor removal operation must be carried out. When the conditions of the motor of the fuel tank 1 allow the operation of eliminating the fuel vapor and the operation of eliminating the fuel vapor must be carried out, the operation of elimination of fuel vapor is carried out, that is, the Electromagnetic valve 60 is closed and the air valve 35 is activated to increase the pressure in the air chamber 6. Therefore, the central portion 5c of the wall 5 moves downward to remove the fuel vapor from the space above the fuel surface in the fuel chamber 7.

In addition, in the eighth embodiment, while the fuel vapor removal operation is being carried out, it is judged towards the rate of increase in pressure in the air chamber 6 being greater than that to which the fuel can be subjected to. moving greatly in the fuel chamber 7 on the basis of the pressure in the air chamber 62 which is detected by the pressure sensor 61. When the rate of increase in pressure in the air chamber 6 is higher than that to which the fuel can move greatly in the fuel chamber 7, the air pump 35 is stopped. On the other hand, when the rate of increase in pressure of the air chamber 6 is less than that to which the fuel can move greatly in the fuel chamber 7, the air pump 35 is activated. Therefore, the rate of increase in pressure in the air chamber 6 is kept lower than that to which the fuel can move greatly in the fuel chamber 7 so that movement of the fuel in the fuel chamber 7 is prevented. gas. When the conditions of the engine and the fuel tank do not allow the operation of eliminating fuel vapor or do not need to carry out any operation to eliminate steam from fuel, the operation to eliminate fuel vapor is stopped, that is to say, the air pump 35 is stopped and the electromagnetic valve 60 is opened. In the eighth embodiment, the air pump 35 corresponds to the means to discharge the gas from the space formed above the fuel surface or to raise the level of the fuel surface, and the level switch 57 or the fuel level gauge 62 corresponds to a means for detecting the level of the fuel surface. The operation of removing fuel vapor in accordance with the eighth embodiment will be explained below with reference to a flow chart in Figure 17. In step 810, it is judged whether the temperature T of the cooling water is higher than a Default temperature TO (T <; TO). The predetermined temperature is that at which purging of the fuel vapor discharged to the intake passage 52 is allowed. When T > TO, it is judged that the cooling water temperature allows purging of the discharged fuel vapor into the intake passage 52 and the routine proceeds to step 812. On the other hand, when T < TO, the cooling water temperature does not allow purging of the fuel vapor discharged to the intake passage 52, the routine proceeds to step 840 where the electromagnetic valve 60 is opened, the routine proceeds to step 842 where the pump 35 and the routine is terminated. In step 812, it is judged whether the level switch 57 is disconnected. When the switch 57 is disconnected, it is judged that the fuel vapor removal operation must be carried out, the routine proceeds to step 814. On the other hand, when the switch 57 is connected, it is judged that no need to carry out any operation to remove the fuel vapor, the routine proceeds to step 840 where the electromagnetic valve 60 is opened, the routine proceeds to step 842 where the pump 35 is stopped, and the routine is terminated. In step 814, it is judged whether the amount F of the fuel in the fuel chamber 7 is larger than a predetermined amount F0 of the fuel (F> F0). The predetermined amount of the fuel is larger than that sufficient to raise the level of the fuel surface to the level higher than the fuel chamber 7 when the partition wall 5 moves downward. In step 814, when F _ > F0, the routine advances step 816. On the other hand, in step 814, when F < F0, the routine proceeds to step 840 where the electromagnetic valve 60 is opened, the routine proceeds to step 842 where the pump 35 is stopped and the routine is terminated. In step 816, it is judged whether the electromagnetic valve 60 is closed. When the valve 60 is closed, the routine proceeds to step 818 where this time the target pressure Pn is calculated by adding a predetermined pressure ΔP to last the time of the target pressure, and the routine proceeds to step 824. another part, in step 816, when the valve 60 is opened, the routine proceeds to step 836 where the valve 60 is closed. The routine proceeds to step 838 wherein the pressure in the air chamber 6 detected by the sensor 61 pressure is admitted to the target pressure Pn as an initial target pressure and the routine is terminated. In step 820, it is judged whether the target pressure Pn is higher than a maximum pressure Pmax (Pn> Pmax).

The maximum pressure is lower than that at which the wall 5 can be damaged by pressure in the air chamber 6. In step 820, when Pn > Pmax, the routine proceeds to step 822 where the maximum pressure Pmax is admitted to the target pressure to limit the pressure in the air chamber 6 to the maximum pressure, and the routine advances to step 824. On the other hand, in the step 820, when Pn < Pmax, the routine advances to step 824.

In step 824, it is judged whether the pressure P in the air chamber 6 is lower than the maximum pressure Pmax (P < Pmax). When P < PMax, it is judged that the pressure in the air chamber 6 allows the operation to eliminate steam from the fuel, the routine proceeds to step 826. On the other hand, when P > P max, it is judged that the pressure in the air chamber 6 does not allow the operation to remove the fuel vapor, the routine proceeds to step 832 where the electromagnetic valve 60 is opened, the routine proceeds to step 834 where the pump 35 air stops, and the routine is terminated. In step 826, it is judged whether the pressure P in the air chamber 6 is lower than the target pressure Pn (P <Pn). When P < Pn, it is judged that the rate of increase in pressure in the air chamber 6 is less than that to which the fuel can move greatly in the fuel chamber, the routine proceeds to step 828 where the electromagnetic valve 60 is closed, the routine proceeds to step 830 where the air pump 35 is activated, and the routine is terminated. On the other hand, in step 826, when P > Pn, it is judged that the rate of increase in pressure in the air chamber 6 is higher than that to which the fuel can move greatly in the fuel chamber 7, the routine proceeds to step 834 where the pump is stopped. of air and the routine is terminated. In the eighth embodiment, the fuel vapor discharged from the fuel chamber is introduced into the intake passage. Therefore, the air-fuel ratio of the air-fuel mixture is decreased by the introduced fuel vapor, that is, the air-fuel ratio is not maintained at a desired predetermined air-fuel ratio. According to the ninth embodiment, the air-fuel ratio is maintained at a predetermined predetermined air-fuel ratio when the discharged fuel vapor is introduced into the intake passage. A fuel reserve device according to the ninth embodiment of the invention will be explained below. In the ninth embodiment, as shown in Figure 18, the fuel reserve device comprises an air-fuel ratio sensor 63 for generating a voltage corresponding to an air-fuel ratio in the intake passage. The air-fuel ratio sensor 63 comprises an oxygen sensor or a linear sensor that generates a voltage corresponding to a concentration of the oxygen in the exhaust gas. The sensor 63 is connected to the inlet 46 through a corresponding AD converter 48. The components other than those described above are the same as those of the fuel reserve device in accordance with the eighth embodiment. Therefore, an explanation of them will not be provided. A fuel vapor removal operation according to the ninth embodiment will be explained below. In the ninth embodiment, it is judged whether the temperature of the cooling water is higher than a predetermined temperature, if the amount of fuel in the fuel chamber 7 is larger than a predetermined amount of fuel, and if the pressure in the chamber of air 6 is lower than a predetermined pressure. The predetermined temperature is higher than that of the cooling water when the cooling water cools the motor in a constant driving condition. The predetermined amount of the fuel is larger than that sufficient to raise the level of the fuel surface to the highest level in the fuel chamber 7 when the wall 5 moves downward, and the predetermined pressure is lower than that at which the wall can be damaged by pressure in the air chamber. When the cooling water temperature is higher than a predetermined temperature, if the amount of fuel in the fuel chamber 7 is larger than a predetermined amount of the fuel, and if the pressure in the air chamber 6 is lower than a predetermined pressure, it is judged that the conditions of the engine and the fuel tank 1 allow the fuel vapor to be purged. Furthermore, in the ninth mode, it is judged whether the switch 57 of the level is switched off. When the switch 57 is disconnected, it is judged that the operation to remove the fuel vapor must be carried out. Further, in the ninth embodiment, it is judged whether the air-fuel ratio detected by the air-fuel ratio sensor 63 is larger than a predetermined ratio. The predetermined ratio is to a desired air-fuel ratio. When the detected air-fuel ratio is larger than the predetermined ratio, it is judged that the air-fuel ratio allows the operation to continue to remove the fuel vapor. When the conditions of the engine and the fuel tank 1 allow the purge of the fuel vapor, the operation of eliminating the fuel vapor must be carried out, and the air-fuel ratio allows the elimination operation to continue to be carried out. of fuel vapor, the fuel vapor removal operation is carried out, that is, the electromagnetic valve 60 is closed, and the air pump 35 is activated to increase the pressure in the air chamber 6. Therefore, the central portion 5c of the wall 5 moves downward to remove the fuel vapor from the space above the fuel surface in the fuel chamber 7. When the air-fuel ratio does not allow the fuel vapor removal operation to continue even when the conditions of the engine and the fuel tank 1 allow the purging of the fuel vapor and the operation of removing the fuel vapor must be carried At this point, the fuel vapor removal operation is stopped, ie the air pump 35 is stopped. Therefore, in accordance with the ninth embodiment, the amount of fuel vapor introduced into the intake passage is controlled so that the air-fuel ratio is maintained at a predetermined desired ratio.

Of course, when the conditions of the engine and the fuel tank 1 do not allow the purging of the fuel vapor or do not need to carry out a fuel vapor removal operation, the fuel vapor removal operation is stopped, ie , the air pump 35 is stopped. In the ninth embodiment, the purging of the fuel vapor into the intake passage corresponds to the means for discharging the gas into the space formed above the fuel surface or for raising the level of the fuel surface and the level switch 57 or the fuel level gauge 62 corresponds to the means for detecting the level of the fuel surface. The operation to remove the fuel vapor in accordance with the ninth embodiment will be explained below with reference to a flow chart in Figure 19. In the flow chart, steps 910, 912 and 914 correspond to steps 810, 812 and 814 in Figure 17, respectively. Therefore, an explanation of them will not be provided. In step 914, when F > F0, the routine advances to step 916. On the other hand, when F < F0, the routine proceeds to step 924 where the electromagnetic valve 60 is opened, the routine proceeds to step 926 where the air pump 35 is stopped, and the routine is terminated. In step 916, it is judged whether the pressure P in the air chamber 6 is lower than the maximum pressure Pmax (P < Pmax). When P < Pmax, it is judged that the pressure in the air chamber 6 allows the operation of eliminating fuel vapor and the routine proceeds to step 918. On the other hand, when P > Pmax, it is judged that the pressure in the air chamber 6 does not allow the operation of eliminating fuel vapor, the routine proceeds to step 924 where the electromagnetic valve 60 is opened, the routine proceeds to step 926 where the pump 35 of air stops, and the routine is terminated. In step 918, it is judged whether the air-fuel ratio AF is larger than the desired predetermined ratio AFO (AF> AFO). When AF > AFO, it is judged, that the air-fuel ratio allows the fuel vapor removal operation to continue, the routine proceeds to step 920 where the electromagnetic valve 60 is closed, the air pump 35 is activated, and the routine It is terminated. On the other hand, when AF < AFO, it is judged that the air-fuel ratio does not allow to continue the operation of removing the fuel vapor, the routine proceeds to step 926 where the air pump 35 is stopped, and the routine is terminated. In the third and seventh modes, the supply of fuel to the fuel chamber is carried out when the pressure in the air chamber is increased. Therefore, the increased pressure in the air chamber can force the fuel in the fuel chamber to flow back into the fuel supply line when the fuel supply in the fuel chamber is stopped. According to the tenth embodiment, the fuel flow in the fuel chamber is again prevented from flowing into the fuel supply line. A fuel reserve device according to the tenth embodiment of the invention will be explained below. In the tenth embodiment, as shown in Figure 20, a fuel level gauge 62 for detecting the amount of fuel in the fuel chamber by detecting the position of the wall 5 is mounted on the upper portion 2 of the fuel tank 1 . The gauge 62 is of the pendulum type, one end of which is placed in the central portion 5c of the wall 5, and the voltage is generated in accordance with the angle of the pendulum (ie, the position of the fuel surface). The generated voltage is admitted to the inlet orifice 46 through the corresponding AD converter 48. The components other than those described above are the same as those of the fuel reserve device in accordance with the seventh embodiment. Thus, an explanation of them will not be provided. A combusitlbe steam elimination operation in accordance with the tenth embodiment will be explained below. The operation to eliminate fuel vapor is carried out in the same manner as in the seventh embodiment until the closing of the lid is allowed to open. Therefore, an explanation of it will not be provided. In the tenth embodiment, after the closing of the lid is opened, the fuel supply to the fuel chamber 7 is carried out until the fuel chamber 7 has been filled with fuel. In addition, in the tenth embodiment, the electromagnetic valve 60 is opened to decrease the pressure in the air chamber 6 when the predetermined time has elapsed. The predetermined time is that from the detection of the fuel chamber 7 that has been filled with the fuel to the stopping of the fuel supply within the fuel chamber 7. Therefore, in accordance with the tenth embodiment, the pressure in the air chamber 6 is decreased when the fuel supply to the fuel chamber 7 is stopped. In this way, fuel flow back to the fuel supply pipe is prevented. In the ninth embodiment, the air pump 35 or the fuel level gauge 62 corresponds to the means for charging the gas from the space formed above the fuel surface or for raising the level of the fuel surface, and the commutator 57 level corresponds to the medium to detect the level of the fuel surface. The fuel vapor removal operation according to the tenth embodiment will be explained below with reference to a flow chart in Figures 21 and 22. In step 1010 in Figure 21, it is judged whether the switch 50 is connected. closing-opening lid. When the switch 50 is turned on, the routine proceeds to step 1012. On the other hand, when the switch 50 is turned off, it is judged that no fuel supply must be carried out to the fuel chamber 7, the routine proceeds to step 1050 in Figure 22 where the end flag is adjusted, the routine advances to step 52 where the air pump 35 is stopped, the routine advances to step 1054 where the electromagnetic valve 60 is opened and the routine advances to step 1056 The end flag is adjusted when closing the lid lock, and readjusted when the first fuel supply, second fuel supply and the contrabanders are readjusted as will be described below. In step 1012 in Figure 21, it is judged whether the level switch 57 is connected. when the switch 57 is connected, it is judged that no operation to remove the fuel vapor needs to be carried out, the routine proceeds to step 1024 where the second fuel supply flag is set, the routine proceeds to step 1026 where the air pump 35 is stopped, the routine proceeds to step 1028 where the electromagnetic valve 60 is opened, the routine advances to step 1030 where opening of the lid closure is allowed to carry out the supply of fuel to the chamber 7, and the routine proceeds to step 1032. The second fuel supply flag is set when the level switch 57 is turned off and readjusted when closed in the lid closure.

On the other hand, in step 1012, when the switch 57 is turned off, it is judged that the operation of removing the fuel vapor must be carried out, and the routine proceeds to step 1014. In step 1014, it is judged whether the pressure P in the air chamber 6 is lower than a maximum pressure Pmax (P <Pmax). The maximum pressure is lower than that at which the wall 5 can be damaged by pressure in the air chamber 6. When P < Pmax, it is judged if the pressure in the air chamber 6 allows the operation to remove the fuel vapor, the routine proceeds to step 1016. On the other hand, when P > Pmax, it is judged if the pressure in the air chamber 6 does not allow the steam removal operation of the fuel, the routine proceeds to step 1022 where the first fuel supply flag is adjusted, the routine advances to step 1026 where the air pump 35 is stopped, the routine proceeds to step 1028 where the electromagnetic valve 60 is opened, and the routine proceeds to step 1030 where opening of the lid closure is allowed and the routine proceeds to step 1032. The first fuel supply flag is adjusted when the pressure in the air chamber 6 is higher than the maximum pressure and readjusted when closing the lid closure.

At step 1016, it is judged whether the first fuel supply flag is readjusted. When the flag is readjusted, it is judged that the pressure in the air chamber 6 has not yet been converted to the maximum pressure, the operation is carried out to remove the fuel vapor, ie the routine advances to step 1018 in where the electromagnetic valve 60 closes. The routine proceeds to step 1020 where the air pump 35 is activated to increase the pressure in the air chamber 6, and the routine is terminated. On the other hand, in step 1016, when the flag is adjusted, it is judged that the air pump 35 should not be activated even when the pressure in the air chamber 6 is less than the maximum pressure, the routine proceeds to step 1026 in where the air pump 35 is stopped, the routine proceeds to step 1028 where the electromagnetic valve 60 is opened, the routine proceeds to step 1030 where the opening of the lid closure is allowed, and the routine proceeds to step 1032. In step 1032, it is judged if the contrabander is readjusted. The contraband is adjusted when the fuel chamber 7 is filled with fuel and readjusted when closing the lid. When readjusting the contraband, it is judged that the fuel chamber 7 is not complete with the fuel yet, and the routine proceeds to step 1034. On the other hand, when the contraband is adjusted, it is judged that the fuel chamber 7 is filled with fuel, and the routine proceeds to step 1042. In step 1034, it is judged whether the fuel chamber 7 is filled with fuel. When the fuel chamber 7 is filled with fuel, the routine proceeds to step 1036 where the account is reset, the routine proceeds to step 1038 where the contraband is adjusted, and the routine is terminated. On the other hand, when the fuel chamber 7 is not filled with the fuel, the routine proceeds to step 1040 in Figure 22. In step 1040, it is judged whether the second fuel supply flag is set. When the second fuel supply flag is adjusted, it is judged that no operation is necessary to remove the fuel vapor and the routine is terminated. On the other hand, when the second fuel supply flag is readjusted, it is judged that the fuel vapor removal operation should be carried out and the routine proceeds to step 1044. In step 1042, it is judged whether the count t is smaller than a predetermined account tO (t <tO). The predetermined count is that between the detection of the fuel chamber 7 that is filled with the fuel and the stopping of the fuel supply to the fuel chamber 7. When t <; tO, the routine proceeds to step 1043 where the count is counted upward, and the routine proceeds to step 1044. On the other hand, in step 1042, when t > tO, it is judged that the fuel supply in the fuel chamber 7 is stopped, the routine proceeds to step 1050 where the end flag is adjusted, the routine proceeds to step 1052 where the air pump 35 is stopped, the routine proceeds to step 1054 where the electromagnetic valve 60 is opened, and the routine proceeds to step 1056. In step 1044, it is judged whether the pressure P in the air chamber 6 is lower than the second predetermined pressure P2 (P < P2). The second predetermined pressure is lower than the fuel pressure when the fuel is supplied through the nozzle filled with fuel. When P < P2, it is judged that the pressure in the air chamber 6 allows the fuel supply to the fuel chamber 7, the routine proceeds to step 1046 where the electromagnetic valve 60 is closed, the routine proceeds to step 1048 where activates the air pump 35 and the routine is terminated. On the other hand, as in step 1044, when P > P2, it is judged that the pressure in the air chamber 6 does not allow the supply of fuel to the fuel chamber 7, the routine proceeds to step 1052 where the air pump 35 is stopped, the routine advances to step 1054 where the electromagnetic valve 60 is opened and the routine proceeds to step 1056. In step 1056, it is judged whether the end flag is adjusted. When the end flag is adjusted, it is judged that the fuel supply to the fuel chamber 7 has been completed, the routine proceeds to step 1058 where the first fuel supply flag is readjusted, the routine proceeds to step 1060 in where the second fuel supply flag is readjusted, the routine proceeds to step 1062 where the contrabander is readjusted, the routine proceeds to step 1064 where the end flag is reset, and the routine is terminated. On the other hand, in step 1056, when the end flag is readjusted it is judged that the fuel supply to the fuel chamber 7 has not been completed and the routine is terminated. In the first to tenth embodiments, the fuel pump 19 is placed in the fuel tank. The shape of the fuel pump 19 is not simple so that the wall 5 can not contact the surface of the fuel around the fuel pump 19. Therefore, a space ll - can be formed between the partition wall 5 and the fuel surface around the fuel pump 19. According to the eleventh embodiment, a space can not be formed between the wall 5 and the fuel surface around the fuel pump 19. A fuel reserve device according to the eleventh embodiment of the invention will be explained below. In the eleventh embodiment, as shown in Figure 23, the fuel pump 19 is placed outside the fuel tank 1. The fuel pump 19 is connected to the fuel filter 21 through a fuel pump line 19a. The pipe 19a extends through the lower portion 3 below the lower opening of the fuel supply pipe 13. The fuel filter 21 is placed in the fuel chamber 7. The pressure regulator 20 is placed downstream of the fuel pump 19. A fuel return passage 64 extends from the pressure regulator 20 into the fuel chamber 7. The passage 64 serves to return the excess fuel to the fuel chamber 7. In the eleventh embodiment, the fuel reserve device does not comprise a pump chamber so that the fuel vapor discharge pipe is removed. The level switch 57 is placed in the lower portion 3 adjacent to the portion 8 of the anchor. The components other than those described above are the same as those of the fuel reserve device in accordance with the fourth embodiment. Therefore, an explanation of them will not be provided. Therefore, in accordance with the eleventh embodiment, the shape within the fuel tank 1 becomes simpler so that no gap is formed between the separation wall 5 and the fuel surface. In the eleventh embodiment, the venting of the fuel vapor into the intake passage corresponds to a means for discharging the gas from the space formed above the fuel surface or raising the level of the fuel surface and the level switch 57 corresponds to the medium to detect the level of the fuel surface. Of course, the eleventh embodiment can be applied to any modality described above. In the first embodiment, the fuel vapor is generated from the fuel in the fuel supply line 13 after the supply of the fuel to the fuel chamber 7 has been completed. In accordance with the twelfth modality, the generation of the fuel vapor from the fuel in the fuel supply pipe 13 is of course impeded. In the twelfth embodiment, as shown in Figure 24, the lower opening of the fuel supply pipe 13 is mounted on the anchor portion 8. The fuel supply pipe 13 is positioned above the lower opening of the fuel supply pipe. same Preferably, the lower opening of the fuel supply pipe 13 is positioned above the highest position in the fuel chamber 7. In this case, the fuel in the fuel supply pipe 13 is completely removed from it. The components other than those described above are the same as those of the fuel reserve device according to the first embodiment. Therefore, an explanation of them will not be provided. Therefore, in accordance with the twelfth embodiment, the fuel in the fuel supply line 13 flows into the fuel chamber 7 by its weight as the fuel in the fuel chamber 7 decreases. In this way, the generation of fuel vapor from the fuel in the fuel supply pipe 13 is prevented. In the twelfth mode, the supply of the fuel to the fuel chamber corresponds to a means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface. Of course, the twelfth modality can be applied to any modality described above. In the twelfth mode, the fuel in the fuel supply line 13 flows into the fuel chamber 7 as the fuel in the fuel chamber 7 decreases. Therefore, a certain time is required until the fuel in the fuel supply pipe 13 flows completely into the fuel chamber 7. In this way, before all the fuel in the fuel supply line 13 flows into the fuel chamber 7, fuel vapor can be generated from the fuel in the fuel supply line 13. In accordance with the thirteenth modality, ¡5 - the generation of fuel vapor in the fuel supply line 13 is prevented. In the thirteenth embodiment, as shown in Figure 25, the air chamber 6 is connected to the air pump 35 through the first connection pipe 34 instead of the atmosphere pipe 34. The first connection pipe 34 is connected to an electromagnetic valve 60 through the second connection pipe 36. The valve 60 is connected to the outlet hole 47 through a corresponding driving circuit 49. The valve 60 is controlled by the electronic control unit 40. A pressure sensor 61 for detecting the pressure in the air chamber 6 is mounted in the upper portion 2 of the tank 1. The sensor 61 is connected to the inlet port 46 through a corresponding AD converter 48. A fuel level gauge 62 for detecting the amount of fuel in the fuel chamber 7 by detecting the position of the separation wall 5 is mounted in the upper portion 2 of the tank 1. The gauge 62 is connected to the inlet orifice 46 through a corresponding AD converter 48. The components other than those described above are the same as those of the fuel reserve device in accordance with the twelfth embodiment. Therefore, an explanation of them will not be provided. A vapor vapor removal operation according to the thirteenth embodiment will be explained below. The operation to eliminate fuel vapor is carried out in the same manner as that in the tenth mode until the closing of the lid is allowed to open. Therefore an explanation of it will not be provided. In the thirteenth embodiment, after the closing of the lid is opened, the fuel supply to the fuel chamber 7 is carried out until the fuel chamber 7 is filled with fuel. In addition, in the thirteenth embodiment, the electromagnetic valve 60 is opened to decrease the pressure in the air chamber 6 when a predetermined period of time has elapsed. The predetermined time is that from the detection of the fuel chamber 7 that is filled with the fuel to just after stopping the fuel supply to the fuel chamber 7. Therefore, in accordance with the thirteenth embodiment, the pressure in the air chamber 6 is decreased when the fuel supply to the fuel chamber 7 is stopped. Therefore, the fuel in the fuel supply line 13 flows into the fuel chamber 7 so that the generation of the fuel vapor in the fuel supply line 13 is further prevented. In the thirteenth embodiment, the air pump 35 corresponds to a means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface, and the level switch 57 or the gauge 62 of fuel level corresponds to a means to detect the level of the fuel surface. The fuel vapor removal operation according to the thirteenth embodiment will be explained below with reference to a flow chart in Figures 26 and 27. In the flow chart, steps 1310 to 1360 except for the step 1342 correspond to steps 1010 to 1060 in Figures 21 and 22, respectively. Therefore, an explanation of them will not be provided. In step 1342, it is judged whether the count t is smaller than the predetermined account tl (t <tl). The predetermined count is that from the detection of the fuel chamber 7 that has been filled with the fuel until just after the stop of fuel supply to the fuel chamber 7. When t < tl, the routine proceeds to step 1343 where the count is counted up, and the routine proceeds to step 1344. On the other hand, in step 1342, when t >; tl, it is judged that the supply of fuel to the fuel chamber 7 is stopped, the routine proceeds to step 1350 where the end flag is adjusted, the routine proceeds to steps 1352 where the air pump 35 is stopped, the routine proceeds to step 1354 where the electromagnetic valve 60 is opened and the routine proceeds to step 1356. In the aforementioned modes, the air pump is activated, or the electromagnetic valve 60 is opened, based on the opening of the the relief valve or the pressure in the air chamber 6 or the level switch 57. However, the air pump can be activated, or the electromagnetic valve 60 can be opened, based on the position of the wall 5. A fuel reserve device according to the fourteenth embodiment of the invention will be explained below. In the fourteenth embodiment, as shown in Figure 28, the fuel reserve device comprises a body 140 of the fuel tank. The 9 - body 140 comprises upper and lower portions 91 and 92 which are generally cup-shaped. These portions 91 and 92 are connected to one another in the flange portions 91a, 92a thereof. A fuel tank 94 forming a fuel chamber 93 therein for reserving and storing the fuel is housed within the body 140. The tank 94 comprises an upper rectangular wall 95 which is deformable and has a stiffness, a lower rectangular wall 96 which is deformable, and has a stiffness, and a band-shaped wall or connecting wall 97 that is deformable, has a stiffness and connects the peripheral edge 95a of the upper wall 95 to the peripheral edge 96a of the lower wall 96, as shown in Figure 29. As shown in Figure 30, the upper lower walls 95 and 96 are deformed in such a way that the walls 95 and 96 swell or expand outwardly when the amount of fuel in the container is increased. reservoir 94. As a result of the deformation of the walls 95 and 96, the connecting wall 97 is bent inwardly. Therefore, the volume of the reservoir 94 is increased. On the other hand, when the amount of the fuel in the reservoir 94 is decreased, the upper and lower walls 95 and 96 that are bent outwardly and the connecting wall 97 that is bent inward they return to their original shapes as shown in Figure 29. Therefore, the volume of the reservoir 94 is decreased. In addition, as shown in Figure 31, when the amount of fuel in the reservoir 94 is decreased, the Upper and lower walls 95 and 96 are deformed in such a way that walls 95 and 96 swell inwardly. As a result of the deformation of the walls 95 and 96, the connection wall 97 is bent inwardly. Therefore, the volume of the reservoir 94 is decreased. The rigidity of the connecting wall 97 is greater than that of the upper and lower walls 95 and 96. An opening 98 of the fuel passage is formed in the central portion of the lower wall 96 of the fuel tank 94. A connection pipe opening 99 is formed in the central portion of the lower portion 92 of the fuel tank body 140. The reservoir 94 is placed in the body 140 of the fuel tank such that the opening 98 of the fuel passage is aligned with the opening 99 of the connecting pipe. An air chamber 110 is formed outside the fuel tank 94 and inside the fuel tank body 140. A fuel level sensor 111 for detecting the position or amount of movement of the upper wall 95 of the tank 94 for calculating the amount of fuel in the tank 94 is mounted on the inner face of the upper portion 91 of the tank body 140 made out of fuel. In addition, an air passage opening 112 is formed in the upper portion 91 of the body 140 of the fuel tank. The volume of the air chamber 110 is increased or decreased when the volume of the fuel tank 94 is decreased or increased. During this time, air can flow in or out of the air chamber 110 through the air passage opening 112. Therefore, the reservoir 94 can easily deform. A filter 113 to prevent objects other than air from flowing into the air chamber 110 is inserted into the opening 112 of the air passage. One end of the fuel pipe 114 for introducing the fuel into the fuel tank 94 and removing the fuel from the tank 94 is inserted into the opening 98 of the fuel passage of the tank 94, and the connecting pipe opening 99 of the portion 92 of the fuel tank body 140 and connects with it.

The other end of the fuel pipe 114 is connected to a lower end of a fuel feed line 115 for feeding the fuel to the tank 94 and one end of the fuel introduction pipe 117 for introducing the fuel from the tank 94 to a fuel pump device 116. The other end of the fuel introduction pipe 117 is connected to the fuel pump device 116. The fuel pump device 116 pumps the fuel in the tank 94 and feeds the fuel to the injectors (not shown) of the engine. One end of a pump fuel vapor pipe 118 for discharging the fuel vapor from the fuel pump device 116 is connected to the fuel pump device 116. The other end of the pump fuel vapor pipe 118 is connected to the fuel supply pipe 115 adjacent an upper opening of the fuel feed pipe 115. further, one end of a fuel conveyor pipe 120 for transporting the fuel from the fuel pump device 116 to the injectors is connected to the fuel pump device 116.

One of the reservoir fuel vapor pipes 150 for discharging the fuel vapor from the reservoir 94 is connected to the upper wall 95 of the reservoir 94. The other end of the reservoir fuel vapor pipe 150 is connected to the device. 116 of fuel pump. In addition, a fuel vapor pipe disconnect valve or reservoir sealing valve 149 is positioned at one end of the reservoir fuel vapor pipe 150. The fuel steam pipe disconnect valve 149 comprises a float 151, the density of which is smaller than that of the fuel. The opening of the tank fuel vapor pipe 150 that is open towards the interior of the tank 94 corresponds to a discharge passage opening to the space above the fuel surface, and the steam shutoff valve 149 The fuel corresponds to a shut-off valve to disconnect the aforementioned discharge passage. One end of a fuel vapor pipe 121 for discharging the fuel vapor adjacent the upper opening 119 therefrom is connected to the fuel supply pipe 115 on the upper opening side and the other end above the pipeline 118 steam pump fuel.

The other end of the fuel vapor pipe 121 is connected to a charcoal can 122 to adsorb the fuel vapor therein and temporarily store the fuel vapor therein. A carbon 123 activated to adsorb the fuel vapor therein is placed in the can 122. The interior of the can 122 is divided by activated carbon 123. Therefore, a fuel vapor chamber 124 is formed on one side of the coal 123, and an air chamber 125 is formed on the other carbon end 123. The other end mentioned above of the fuel vapor pipe 121 is connects to the fuel vapor chamber 124 in the can 122. In addition, one end of a fuel vapor pipe 126 of the can to discharge the vapor of the fuel adsorbed on the activated coal 123 from the can 122 to the intake passage 127 of the engine, it is connected to the chamber 124 of the fuel vapor. The other end of the fuel vapor pipe 126 of the canister is connected to a compensation tank 128 formed in the intake passage 127. A valve 129 for controlling the amount of fuel vapor 129 to open or close the pipe 126 of The fuel vapor from the canister is placed in the steam canister 126 of the canister fuel. The valve 129 for controlling the amount of fuel vapor is controlled by a control unit (not shown). One end of an air pipe 130 for introducing the air into the air chamber 125 of the can 122 is connected to the air chamber 125. The other end of the air pipe 130 is connected with an air cleaner 131 placed in the intake passage 127. A shut-off valve 132 for opening or closing the air pipe 130 is placed in the air pipe 130. The shut-off valve 132 is controlled by a control unit (not shown). A throttle valve 133 for controlling the amount of air that is fed to a motor body 180, of a motor, is placed in the intake passage 127. In the fourteenth embodiment, the steam quantity control valve 129 is opened. of fuel when the fuel vapor in the charcoal can 122 is to be introduced into the intake passage 127. The control valve 129 for the amount of fuel vapor is normally closed. Therefore, when the fuel vapor quantity control valve 129 is opened the negative pressure in the compensation tank 128 is introduced into the can 122 through the fuel vapor pipe 126 of the can and the air in the canister 122. the air cleaner 131 is introduced into the can 122 through the air pipe 130. In this way, the fuel vapor in the canister 122 is introduced into the intake passage 127. Furthermore, the fuel vapor quantity control valve 129 is controlled on the basis of the driving conditions of the engine to control the amount of steam from the engine. fuel to be introduced into the intake passage 127 in such a way that a desired predetermined air-fuel ratio can be obtained. Therefore, the valve 129 for controlling the amount of fuel vapor corresponds to a means for controlling the amount of fuel vapor to be discharged to the intake passage 127, and the shut-off valve 132 corresponds to a means for control the interruption of air in the can 122. In the fourteenth mode, when a leak in the fuel system that is in communication with the charcoal can 122 is to be detected, a negative pressure is introduced into the extending fuel system from the canister 122 to the body 140 of the fuel tank and then, the fuel vapor and closing quantity control valves 129 and 132 are closed to seal the aforementioned fuel system. Then, when an increase in pressure in the fuel system is detected towards atmospheric pressure by means of a pressure sensor (not shown), it is judged that the fuel system has an escape or leakage portion. Therefore, valves 129 and 132 of the fuel vapor quantity and closing control correspond to the means for detecting fuel leakage or leakage. The fuel pump device according to the fourteenth embodiment of the invention will be explained below in detail. In the fourteenth embodiment, as shown in Figure 32, the fuel pump device 116 comprises a pump chamber 153 defined by a housing 152. The pump chamber 153 is divided into a pump chamber portion 155 and a chamber 156 of sub-tank by the partition wall 154 of the pump chamber. The pump chamber partition wall 154 comprises a vertical wall 154a that extends generally vertically and downwardly from an inner face of the upper wall of the housing 152, and a horizontal wall 154b extending horizontally towards the inner side of the chamber 152a. a side wall of the housing 152 above an inner face of a lower wall of the housing 152. A previously mentioned end of the pump fuel vapor pipe 118 for discharging the fuel vapor from the pump chamber portion 155 is connected with the upper wall of the housing 152. The opening at one end of the pump fuel vapor pipe 118 is open adjacent to the upper wall of the housing 152 in the portion 155 of the pump chamber. A fuel pump 157 for feeding the fuel from the sub-tank chamber 156 to the injectors through the fuel conveyor line 120 is placed in the sub-tank chamber 156. The first fuel filter 158 for filtering the pumped fuel to the fuel pump 157 is connected to a lower wall of the fuel pump 157. In addition, a pressure regulator 159 for regulating the pressure of the fuel pumped by the fuel pump 157 it is placed in fuel conveyor pipe 120 in chamber 156 of the sub-tank. An upper end of the fuel return pipe 161 for returning a portion of the fuel pumped by the fuel pump 157 into the chamber 156 of the sub-tank is connected to the pressure regulator 159. In addition, a second fuel filter 160 for filtering the fuel pumped from the fuel pump 157 is placed in the fuel conveyor line 120 between the pressure regulator 159 and the fuel pump 157. A lower tip portion 162 in the fuel return pipe 161 is usually directed horizontally, and tapers in such a manner that the diameter of the tip portion 162 becomes smaller as the tip portion 162 advances towards an opening thereof. The lower tip portion 162 is housed in a negative pressure generating housing 163 to generate a negative pressure by returning or recirculating a portion of the fuel pumped by the fuel pump 157 into the chamber 156 of the sub-tank. The negative pressure generator housing 163 comprises a trumpet-shaped fuel discharge pipe 164 tapering in such a way that the diameter of the fuel discharge pipe 164 becomes larger as the fuel discharge pipe 164 moves towards an opening of it. The fuel discharge pipe 164 is aligned with a lower tip portion 162. In addition, a lower end of the reservoir fuel vapor pipe 150 is housed in the negative pressure riser housing 163. The reservoir fuel vapor pipe 150 in the sub-tank chamber 156 comprises a sub-tank chamber negative pressure introducing pipe 165 for introducing the negative pressure into the sub-tank chamber 156. The introduction pipe 165 opens into the interior of the sub-tank chamber 156 in the upper area in the sub-tank chamber 156. In addition, the diameter of the introduction pipe 165 is smaller than that of the fuel vapor pipe 150. A vertical annular wall 167 extending vertically and downward from the horizontal wall 154b of the separation wall 154 of the pump chamber is placed on the horizontal wall 154b. The vertical annular wall 167 forms a fuel intake passage 166 for introducing the fuel into the chamber 156 of the sub-tank. The location of a top opening of the fuel intake passage 166 is lower than that of a face of the bottom wall of the fuel introduction pipe 117. A horizontal annular wall 168 extending horizontally from the annular vertical wall 167 toward the fuel discharge pipe 164 is positioned at a lower end of a vertical annular wall 167. The horizontal annular wall 168 forms a fuel passage passage 169 for passing the fuel discharged from the fuel discharge pipe 164.

A separation wall 170 having a mesh structure for separating the gases from the fuel is placed in the vertical annular wall 167 and the portion 155 of the pump chamber. The partition wall 170 extends upwardly from a bottom face of the horizontal annular wall 168 into the interior of the fuel inlet passage 166. Therefore, the separation wall 170 crosses the passage 169 that passes the fuel. In addition, the partition wall 170 extends into the interior of the pump chamber portion 155 through the vertical annular wall 167. The lateral sides of the partition wall 170 in the vertical annular wall 167 extend to the inner face of the vertical annular wall 167. Therefore, the separation wall 170 divides the fuel intake passage 166 into two portions. In addition, the partition wall 170 extends into the interior of the pump chamber portion 155 beyond the horizontal wall 154b. The upper end of the partition wall 170 in the portion 155 of the pump chamber is placed higher than the opening of the fuel introduction pipe 117. Also, the side sides of the partition wall 170 in the portion 155 of the pump chamber are connected to the inner face of the cylindrical wall of the housing 152. A bottom end of the partition wall 170 in the portion 155 of the pump chamber, connects with the horizontal wall 154b. An operation of the fuel pump device according to the fourteenth embodiment of the invention will be explained below. The fuel in the sub-tank chamber 156 is pumped to the fuel pump 157 through the first fuel filter 158 when the fuel pump 157 is activated to feed the fuel in the fuel tank 94 to the injectors. The fuel pumped into the fuel pump 157 is fed to the pressure regulator 159 through the second fuel filter 160. When the fuel pressure is higher than a predetermined pressure in the pressure regulator 159, a portion of the fuel is made return to chamber 156 of the sub-tank through line 161 of fuel return. Therefore, the pressure regulator 159 and the fuel return line 161 correspond to the means for recirculating the fuel. In this way, the fuel pressure is maintained at a predetermined pressure.

The remaining fuel having the predetermined pressure is fed to the injectors 120 through the fuel conveyor pipe 120. The fuel returned to the chamber 156 of the sub-tank through the fuel return line 161 is discharged from the lower tip portion 162 into the negative pressure generating housing 63. The venturi effect of the tapering lower tip portion 162 increases the flow rate of the fuel discharged from the lower tip portion 162. The fuel having the increased flow rate flows into the fuel passage passage 169 through the fuel discharge pipe 164. When the fuel is discharged from the lower tip portion 162 towards the fuel discharge pipe 164 to increase the flow rate thereof, a negative pressure is generated in the negative pressure generating housing 163. Therefore, the fuel return pipe 161 and the negative pressure generating housing 163 correspond to the means for generating the negative pressure. The negative pressure generated in the negative pressure generating housing 163 is introduced into the space above the fuel surface of the tank 94 through the fuel vapor pipe 150 and into the space above the fuel surface in the chamber 156 of the sub-tank through the steam pipes 150 and 165 of the fuel tank and introduction of negative pressure of the sub-tank. Thus, the pipes 150 and 165 of the tank fuel vapor entering the negative pressure of the sub-tank correspond to the medium or passage to introduce the negative pressure. In the fourteenth embodiment, the diameter of the tank fuel vapor pipe 150 is larger than that of the negative pressure introduction pipe 165 of the sub-tank. Therefore, the negative pressure is introduced into the reservoir 94 to discharge the gases including steam from the fuel and air from the reservoir 94 with priority. Therefore, the negative pressure introduction pipe of the sub-tank corresponds to the means to facilitate the discharge of the gases from the tank 94 with priority. When the negative pressure is introduced into the reservoir 94, fuel vapor and air are discharged from the reservoir 94 into the negative pressure generating housing 163, and, as a result, the level of the fuel surface in the reservoir 94 is elevates to the highest position in the fuel chamber 93. Therefore, the fuel pump 157 corresponds to a means for discharging the gas from the space formed above the fuel surface or for raising the level of the fuel surface. In the fourteenth embodiment, once gases such as fuel vapor or air have been completely removed from the reservoir 94, the reservoir 94 is maintained at a condition in which there is no gas therein when the pump is activated. fuel 157. Further, when the reservoir 94 is maintained in the condition in which there is no gas therein, the upper face of the fuel reservoir 94 represents the exact amount of the fuel in the reservoir 94. Therefore, in accordance with the fourteenth mode, the amount of fuel in tank 94 is accurately detected. If the negative pressure can continue to be introduced into the reservoir 94 after the fuel engine and air have been removed from the reservoir 94, fuel may leak from the reservoir 94 to the reservoir fuel vapor pipe 150. Therefore, the introduction of the negative pressure in the tank 94 must be stopped when the fuel vapor and air have been removed from the tank 94. In the fourteenth mode, when the fuel and air vapor have been completely removed from the tank 94, and the level of the fuel surface in the reservoir 94 reaches the fuel vapor shut-off valve 149, the valve 149 closes the fuel vapor pipe 150 from the reservoir. Therefore, the fuel shutoff valve 149 corresponds to the means for stopping the introduction of the negative pressure in the reservoir 94. In addition, the valve 149 corresponds to the means for preventing leakage or leakage of the fuel from the reservoir 94. After the fuel steam shut-off valve 149 closes the vapor pipe 150 of the fuel tank, negative pressure is introduced only into the space above the fuel surface in the sub-tank chamber 156. As shown in FIG. When the negative pressure is introduced into the space above the surface of the fuel in the chamber 156 of the sub-tank, the vapor of the fuel and the air are discharged from the aforementioned space towards the housing 163 generating the negative pressure. The negative pressure introduced raises the level of the surface of the fuel in the chamber 156 of the sub-tank, and the fuel is introduced from the portion 155 of the pump chamber to the chamber 156 of the sub-tank through the intake passage 166 made out of fuel. Therefore, the level of the fuel surface in chamber 156 of the sub-tank is maintained at a predetermined height as long as there is a quantity of the fuel in the portion 155 of the pump chamber. In this way, when the fuel pump device 116 is tilted, and the fuel surface in the resulting chamber 156 is tilted, the condition in which there is no fuel around the first fuel filter 158 through which the fuel is pumped into the fuel pump 157, is of course prevented. Therefore, the fuel return pipe 161 and the negative pressure generating housing 163 correspond to the means for preventing fuel drying. The vapor of the fuel and air discharged from the spaces above the fuel surfaces in the tank 94 and the chamber 156 of the sub-tank are retained with the fuel in the negative pressure generating housing 163. The fuel including fuel vapor and air is discharged to the fuel passage passage 169 through the fuel discharge pipe 164. The fuel discharged to the fuel passage passage 169 passes through the lower opening of the fuel intake passage 166. During this time, the vapor of the air fuel included in the fuel moves up due to its lower densities. Then, the fuel vapor and air are discharged from the 156 and the 10 sub-tank to the portion 155 of the pump chamber through one of the portions of the fuel intake passage 166 divided by the partition wall 170. As mentioned above, in the fourteenth embodiment, the fuel inlet passage 166 serves as both a fuel introduction passage for introducing the fuel into the sub-tank chamber 156 and a fuel vapor discharge passage. to discharge the fuel vapor from chamber 156 of the sub-tank. Therefore, there is no need to provide another fuel vapor discharge passage in addition to the fuel intake passage 166. In this way, it is possible to make the fuel pump device small because the fuel intake passage 166 functions as the fuel introduction passage and the fuel vapor discharge passage. Further, in the fourteenth embodiment, when the fuel discharged to the fuel passage passage 169 flows below the lower opening of the fuel intake passage 166, the fuel passes through the separation wall 170. Therefore, the fuel vapor and air are separated from the fuel by the separation wall 170 and discharged to the portion 155 of the pump chamber through the fuel intake passage 166. In this way, the separation wall 170 corresponds to the means for separating the gases from the fuel. In addition, in the fourteenth modality, the passage The fuel passage 169 is directly connected to the fuel intake passage 166 and is generally perpendicular relative to the fuel intake passage 166. Therefore, the fuel vapor and air can easily move upward to separate from the fuel. In this way, the passing fuel and the fuel intake passages 169 and 166 correspond to the means for separating or discharging the gases from the fuel. The steam from the fuel discharged to the portion 155 of the pump chamber is introduced into the charcoal can 122 through the pump fuel vapor line 118. A lower opening of the pump fuel vapor pipe 118 opens into the interior of the portion 155 of the pump chamber adjacent the upper wall of the housing 152. Therefore, the fuel vapor in the portion 155 of the The pump chamber can be inserted into the canister 122 until the amount of the fuel in the portion 155 of the pump chamber becomes smaller.

The fuel in chamber 156 of the sub-tank is heated by the fuel pump 157. Therefore, the temperature of the fuel in the chamber 156 of the sub-tank is higher than that of the fuel in the portion 155 of the pump chamber. If the fuel having a relatively high temperature is mixed with the fuel having a relatively low temperature in the portion 155 of the pump chamber, a large amount of the fuel vapor can be generated. Further, if the fuel flows out of the chamber 156 of the sub-tank to the portion 155 of the pump chamber when the amount of the fuel in the sub-tank chamber 156 is very small, the fuel may be dried around the first filter 158 of fuel. Therefore, the flow of fuel from the chamber 156 of the sub-tank to the portion 155 of the pump chamber should be prevented. According to the fourteenth embodiment, the fuel passage passage 169 is generally perpendicular relative to the fuel intake passage 166. Therefore, the flow of fuel from the fuel passage passage 169 to the pump chamber portion 155 is prevented. In this way, the passing fuel and the fuel intake passages 169 and 166 correspond to the means to prevent the fuel from flowing outwards., the generation of fuel vapor or the drying of fuel. The fuel in the tank 94 is introduced into the portion 155 of the pump chamber through the fuel introduction pipe 117 as the fuel in the sub-tank chamber 156 is fed to the injector by the pump device 116 made out of fuel. A portion of the fuel introduced into the pump chamber portion 155 through the fuel introduction pipe 117 passes through the separation wall 170. Therefore, the vapor of the fuel included in the fuel in the tank 94 is separated in the portion 155 of the pump chamber. In the fourteenth embodiment, the fuel introduction pipe 117 is placed in the lower position than the bottom wall 96 of the tank 94. Therefore, the fuel in the tank 94 can be completely introduced into the portion 155 of the fuel chamber. bomb. In addition, the upper opening of the fuel intake passage 166 is positioned lower than the bottom face of the pipe wall of the fuel introduction pipe 117. Therefore, the fuel in the section 155 of the pump chamber can be completely introduced into the chamber 156 of the sub-tank. In this way, if the amount of the feed in the tank 94 becomes small, the fuel in the tank 94 can be introduced into the chamber 156 of the sub-tank because of the difference in height between the tank 94 and the pipeline. 117 of introduction of fuel. When the fuel pump device 116 is inclined, the surface of the fuel in the portion 155 of the pump chamber of the fuel inlet passage 166 can reach the lower end of the fuel inlet passage 166. When the level of the surface of the fuel exceeds the lower end of the fuel intake passage 166 and exceeds the low position of the uppermost end of the fuel intake passage 166, the fuel in the sub-tank chamber 156 flows into the portion 155 of the pumping chamber. As stated above, the flow of fuel from the chamber 156 of the sub-tank to the portion 155 of the pump chamber can lead to the generation of the fuel vapor and the portion 155 of the pump chamber. Further, if the fuel flows out of the chamber 156 of the sub-tank to the portion 155 of the pump chamber when the amount of fuel in the sub-tank chamber 156 is very small, the fuel may be dried around the first filter of fuel 158.

According to a fourteenth embodiment, the vertical annular wall 167 extends downwardly from the horizontal wall 154b to a relatively large degree. Therefore, it prevents the surface level of the fuel exceeding the lower end of the fuel inlet passage 166 and exceeding the lowest position of the upper end of the fuel intake passage 166. In this way, the vertical annular wall 167 corresponds to a means for preventing fuel from flowing out or generating fuel vapor. Further, the effect of preventing the fuel from flowing out depends only on the length or size of the fuel intake passage 166 (or the ratio between the positions of the upper and lower ends of the fuel intake passage 166) and the angle inclined relative to the horizon of the fuel surface in the fuel intake passage 166. That is, the effect of preventing outflow of the fuel can be obtained independently of the position of the fuel intake passage 166. Therefore, possible selections of the position of the fuel intake passage 166 can be increased. Further, in order to facilitate the separation of the gases from the fuel discharged from the fuel passage, it is desirable that the fuel be below the fuel inlet passage for a prolonged period. In accordance with another embodiment as shown in Figure 34, the fuel passage passage is directed downward and connected to the fuel inlet passage. Therefore, the fuel discharged from the fuel passage passage flows downward in the fuel inlet passage. In this way, the fuel can remain below the fuel intake passage for a prolonged period. A fuel pump device according to the fifteenth embodiment of the invention will be explained below. In the fourteenth embodiment, fuel is introduced into the fuel pump device 116 through the fuel introduction pipe 117 when the fuel is supplied to the tank 94 through the fuel supply pipe 115. The fuel introduced in the fuel pump device 116 flows into the chamber 156 of the sub-tank. Therefore, the level of the fuel surface in chamber 156 of the sub-tank rises. In the fourteenth embodiment, the interior of the tank 94 is in direct communication with the interior of the sub-tank chamber 156 through the negative pressure introduction pipe 165 of the sub-tank chamber. Therefore, the fuel vapor and air can flow back into the tank 94 through the fuel vapor pipe 150 of the tank. In accordance with the fifteenth embodiment, the flow of gases from the chamber 156 of the sub-tank back to the reservoir 94 while preventing the supply of the fuel. In the fifteenth embodiment, as shown in Figures 35 and 36, the negative pressure intrusion pipe 165 of the sub-tank chamber is not placed in the fuel vapor pipe 150 of the tank. A negative pressure introduction pipe 173 of the sub-tank chamber is placed in the sub-tank chamber 156 independently of the pipe 150 of the fuel vapor of the tank. An upper opening in the negative pressure introduction pipe 173 of the sub-tank chamber opens into the chamber 156 of the sub-tank in the upper area in the chamber 156 of the sub-tank. On the other hand, a lower opening of the negative pressure introduction pipe 173 of the sub-tank chamber opens towards the interior of the negative pressure generating housing 163. The diameter of the lower opening of the negative pressure introduction pipe 173 of the sub-tank chamber is smaller than that of the fuel vapor pipe 150 of the tank. The components other than those described above are the same as those of the fuel pump device according to the fourteenth embodiment. Thus, an explanation of them is not provided. An operation of the fuel pump device according to the fifteenth embodiment of the invention will be explained below. The fuel is introduced into the chamber 156 of the sub-tank when the fuel is introduced into the tank 94 through the fuel supply pipe 115. Therefore, the level of the fuel surface in chamber 156 of the sub-tank rises. In the fifteenth embodiment, the space above the fuel surface in chamber 156 of the sub-tank does not remain in direct communication with the interior of reservoir 94. Therefore, the flow of fuel vapor and air from the chamber 156 of the sub-tank back to tank 94, while fuel supply is prevented. In this way, the amount of fuel vapor and air in the reservoir 94 is kept small before the fuel pump 157 is activated. Therefore, the fuel vapor and the - - air can be quickly removed from the reservoir 94 when the fuel pump 157 is activated. Operations other than those described above are the same as those of the fuel pump device in accordance with the fourteenth embodiment. Therefore, an explanation of them will not be provided. In the aforementioned embodiment, a sensor for detecting gases including fuel vapor in the space above the fuel surface in the fuel chamber can be used, instead of the level switch. In addition, the operation of removing steam from the fuel to open or close the above-mentioned shut-off valves can be controlled on the basis of the amount of the gases in the fuel chamber or the volume of space formed above the fuel surface, instead of the highest level of the fuel's surface. In addition, the operation to remove the vapor from the fuel can be controlled on the basis of judgment if the level of the fuel surface is higher than a predetermined level, or if the amount of gas in the fuel chamber is greater than a predetermined amount. . Of course, in the above-mentioned modes it is judged that there is a quantity of gas in the fuel chamber when the level sensor is switched off. Although the invention has been described with reference to specific embodiments that are selected for purposes of illustration, it should be apparent that numerous modifications may be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.

Claims

CLAIMS:

1. A fuel reserve device for reserving fuel therein comprising: a wall for dividing an interior of the device in a fuel chamber and an air chamber, the wall being deformable in accordance with the amount of fuel in the chamber of gas; a discharge passage opening to the space formed above the fuel surface in the fuel chamber; a shut-off valve for normally closing the discharge passage; a gas discharge means for discharging the gas from the space through the discharge passage when the shut-off valve is open; and a control means for controlling the gas discharge means and the shut-off valve to open the shut-off valve and operate the gas discharge means to discharge the gas from the space when the amount of the gas is larger than a gas. predetermined amount, the control means closes the shut-off valve and stops the operation of the gas discharge means to stop the gas discharge operation when the amount of the gas is smaller than the predetermined amount.

A fuel reserve device according to claim 1, wherein the fuel surface level detecting means is provided for detecting the level of the fuel surface in the fuel chamber, and a control means judges that the amount of the gas is greater than the predetermined amount when the level of the fuel surface detected by the fuel surface detecting means is lower than a predetermined level.

A fuel reserve device according to claim 1, wherein the means for raising the fuel surface level is provided to raise the level of the fuel surface, and the gas discharge means controls the means for raise the fuel surface level to raise the level of the fuel surface to discharge the gas from the space when the amount of the gas is larger than the predetermined amount.

A fuel reserve device according to claim 3, wherein the means for raising the level of the fuel surface feeds the fuel into the fuel chamber to raise the level of the fuel surface.

A fuel reserve device according to claim 3, wherein the means for raising the level of the fuel surface deforms the wall to raise the surface level of the fuel.

6. A fuel reserve device according to claim 5, wherein the means for raising the level of the fuel surface increases the pressure in the air chamber to deform the wall.

7. A fuel reserve device according to claim 6, wherein the means for raising the level of the fuel surface increases the pressure in the air chamber to a pressure lower than that of the fuel fed into the fuel chamber. fuel when the fuel is fed into the fuel chamber.

A fuel reserve device according to claim 6, wherein the means for raising the level of the fuel surface decreases the pressure in the air chamber when the fuel supply to the fuel chamber is stopped.

A fuel reserve device according to claim 5, wherein the means for raising the level of the fuel surface introduces a negative pressure in the space to deform the wall.

A fuel reserve device according to claim 9, wherein the means for raising the surface level of the fuel comprises a fuel pump for pumping the fuel to generate a negative pressure by the pumped fuel., and introduces the negative pressure in the space through the discharge passage.

A fuel reserve device according to claim 10, wherein the means for raising the surface level of the fuel returns to a portion of the fuel pumped by the fuel pump into the fuel chamber to generate the negative pressure.

A fuel reserve device according to claim 10, wherein the fuel pump is housed in a pump chamber connected to the fuel chamber, the means for raising the level of the fuel surface returns to the portion of the fuel pumped by the fuel pump into the pump chamber to generate the negative pressure and introduce the negative pressure into the space formed above the fuel surface in the pump chamber.

13. A fuel reserve device according to claim 9, wherein the discharge passage is connected to an air intake system of an engine, and the means for raising the fuel surface level introduces negative pressure into the system of air intake into the space formed above the surface of the fuel through the discharge passage.

A fuel reserve device according to claim 13, wherein the discharge passage is connected to the air intake system through a canister to adsorb the fuel vapor therein, and the can comprises a valve that flows into the atmosphere when the pressure in the boat is under a predetermined negative pressure to cause the boat to communicate with the atmosphere.

15. A fuel reserve device according to claim 13, wherein the means for raising the surface level of the fuel raises the level of the fuel surface when the condition in the engine allows it to receive the fuel vapor.