Fuel tank system

A fuel tank system 12 includes: a communicating pipe 30 that has plural open portions 54A and 54B positioned higher than a full level inside a fuel tank 14 and communicates the inside of the fuel tank 14 with a canister 32; and a valve member 42 that is disposed outside the fuel tank 14 and, on the basis of a state of inclination of fuel detected by a fuel inclination sensor 60, closes the communicating pipe corresponding to an open portion predicted to be positioned in the fuel and opens the communicating pipe corresponding to an open portion predicted to be positioned in a gas layer section.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese Patent Application No. 2015-235195, filed on Dec. 1, 2015, the disclosure of which is incorporated by reference herein in its entirety.

FIELD

Preferred embodiments relate to a fuel tank system.

BACKGROUND

Japanese Patent Application Laid-open (JP-A) No. H5-254352 discloses a fuel outflow prevention device for a vehicle fuel tank having a structure where a float valve and a fuel outflow prevention valve are disposed inside a gas chamber in a fuel tank and where an evaporation passage communicated with the outflow prevention valve is opened and closed by an electromagnetic valve.

In the technology disclosed in JP-A No. H5-254352, during refueling, the electromagnetic valve is closed. Because of this, when the fuel level reaches a full level, the float valve becomes closed and the evaporation passage becomes cut off, so the gas chamber becomes tightly closed to thereby prevent overfill when the fuel tank is full.

Then, when refueling is completed, the electromagnetic valve is opened so that the fuel outflow prevention valve communicates the gas chamber to a canister, so the pressure of the gas chamber inside the fuel tank is maintained equal to or lower than a fixed pressure. Additionally, when the vehicle becomes inclined or overturns, the float valve and the fuel outflow prevention valve become closed to thereby stop fuel outflow from the fuel tank.

In the structure disclosed in JP-A No. H5-254352, a valve having a float (the float valve that regulates the full level or the fuel outflow prevention valve) is disposed in open portions (sections opening to the inside of the fuel tank) of the evaporation passages. Because of this, when the fuel is inclined, the valve having the float becomes immersed in the fuel to ensure that liquid fuel does not move from a communicating pipe to the canister.

In the structure disclosed in JP-A No. H5-254252, by ensuring that the fuel outflow prevention valve does not become immersed in the fuel inside the fuel tank even in a state in which the fuel surface is inclined, the gas in the gas chamber (gas layer) can be moved to the canister to prevent an excessive increase in the internal pressure of the fuel tank. However, the valve having the float has a predetermined height, so when the liquid level when the fuel surface is inclined is set lower than this valve, the full level also becomes set low. For this reason, the inside of the fuel tank cannot be effectively used to increase the effective capacity of the fuel tank (the amount of fuel that the fuel tank can hold).

In consideration of the circumstances described above, an object of the present disclosure is to make it possible for the gas to move from the fuel tank to the canister when the fuel surface in the fuel tank is inclined and to ensure a large effective capacity for the fuel tank.

SUMMARY

A fuel tank system of a first aspect includes: a fuel tank that holds fuel; a canister that adsorbs fuel vapor; a communicating pipe that has plural open portions positioned higher than a full level inside the fuel tank and communicates the inside of the fuel tank with the canister; a fuel inclination sensor that detects a state of inclination of a fuel surface with respect to the fuel tank; and a valve member that is disposed outside the fuel tank and, on the basis of the state of inclination detected by the fuel inclination sensor, closes the communicating pipe corresponding to an open portion, among the plural open portions, predicted to be positioned in the fuel and opens the communicating pipe corresponding to an open portion predicted to be positioned in a gas layer section of the fuel tank.

The fuel inclination sensor detects the state of inclination of the fuel surface with respect to the fuel tank. The valve member, on the basis of the state of inclination of the fuel surface detected by the fuel inclination sensor, closes the communicating pipe corresponding to the open portion, among the plural open portions of the communicating pipe, predicted to be positioned in the fuel and opens the communicating pipe corresponding to the open portion predicted to be positioned in the gas layer section. The communicating pipe corresponding to the open portion predicted to be positioned in the fuel is closed, so movement of the liquid fuel from the communicating pipe to the canister is prevented. The communicating pipe corresponding to the open portion predicted to be positioned in the gas layer section of the fuel tank is opened, so fuel in the gas layer section of the fuel tank is able to move to the canister by means of the communicating pipe.

The valve member is disposed outside the fuel tank, and it is not necessary to dispose inside the fuel tank a float valve for preventing movement of the liquid fuel to the canister when the fuel is inclined. It is not necessary to set the full level low in order to avoid immersion of the float valve in the fuel, so a large effective capacity for the fuel tank (the amount of fuel that the fuel tank can substantially hold) can be ensured.

A second aspect is the fuel tank system of the first aspect, further including: a vapor pipe that has, in a center in a longitudinal direction of the fuel tank as seen in a plan view of the fuel tank, a vapor outlet positioned higher than the full level inside the fuel tank and communicates the inside of the fuel tank with the canister; and a full-tank regulating valve that is disposed in the vapor outlet and closes the vapor outlet by means of a float floating on the fuel inside the fuel tank.

When refueling the fuel tank, the full-tank regulating valve becomes closed when the fuel surface reaches the full level to thereby prevent the gas from moving from the inside of the fuel tank through the vapor pipe to the canister. That is, by disposing the full-tank regulating valve in the vapor outlet of the vapor pipe, a state in which the fuel surface does not go beyond the full level can be reliably realized.

The vapor outlet in which the full-tank regulating valve is disposed is positioned in the center in the longitudinal direction of the fuel tank, so the full-tank regulating valve is also positioned in the center in the longitudinal direction of the fuel tank. Even when the fuel tank is inclined when refueling the fuel tank, the effects of this inclination can be reduced to reduce variations in the amount of fuel inside the fuel tank when the fuel tank is full.

A third aspect is the fuel tank system of the second aspect, wherein the open portions are positioned on edge portion sides of the fuel tank relative to the vapor outlet as seen in a plan view of the fuel tank.

The open portions (in which it is not necessary to dispose a float valve) are positioned on the edge portion sides of the fuel tank, so when the fuel surface is inclined, it is easy to realize a state in which an open portion is positioned in the gas layer section.

Additionally, because when the fuel surface is inclined a state in which an open portion is positioned in the gas layer section is realized, the full-tank regulating valve may be positioned in the fuel. That is, when the fuel surface is inclined, it is not necessary for the full-tank regulating valve to be in the gas layer, and the liquid level can be set high.

A fourth aspect is the fuel tank system of the third aspect, wherein the communicating pipe has a common pipe shared in common on a canister side and plural branch pipes branching on an open portion side.

The communicating pipe is shared in common by the common pipe on the canister side of the branch portion, so compared to a structure where there is a separate communicating pipe for each open portion from the fuel tank to the canister, this can contribute to a reduction in weight and a reduction in the number of parts.

A fifth aspect is the fuel tank system of the fourth aspect, wherein the common pipe also functions as the vapor pipe on the canister side.

That is, the common pipe, which is part of the communicating pipe, also functions as part of the vapor pipe, so compared to a structure where the communicating pipe and the vapor pipe are completely separate, this can contribute to a reduction in weight and a reduction in the number of parts.

A sixth aspect is the fuel tank system of the fifth aspect, wherein the valve member includes: a rotating valve that is disposed in a branch portion of the communicating pipe at which the branch pipes branch and has communicating holes that communicate the common pipe with specific branch pipes among the plural branch pipes in accordance with an angle of rotation of the rotating valve; and a control device that causes the rotating valve to rotate predetermined angles on the basis of the fuel surface detected by the fuel inclination sensor so that the communicating holes communicate the common pipe with the specific branch pipes among the branch pipes.

By simply adjusting the angle of rotation of the rotor, the common pipe can be communicated with specific branch pipes by the communicating holes. The rotor is disposed in the branch portion, and it is not necessary to dispose an opening and closing valve in each of the branch pipes, so this can contribute to a reduction in the number of parts. Furthermore, it suffices for the control device to control the angle of rotation of the one rotor, and the control device does not need to control plural opening and closing valves, so control is easy.

A seventh aspect is the fuel tank system of the sixth aspect, wherein the rotating valve communicates the common pipe with the vapor pipe on a fuel tank side in accordance with the angle of rotation of the rotating valve.

The rotor also opens and closes the vapor pipe, so it is not necessary to dispose a new member (e.g., a valve member) for opening and closing the vapor pipe, and this can contribute to a reduction in weight and a reduction in the number of parts.

An eighth aspect is the fuel tank system of any of the first to seventh aspects, wherein the fuel inclination sensor includes: a vehicle angle-of-inclination sensor that detects an angle of inclination of a vehicle in which the fuel tank is installed; and an acceleration sensor that detects acceleration of the vehicle.

The angle of inclination of the vehicle detected by the vehicle angle-of-inclination sensor and the acceleration of the vehicle detected by the acceleration sensor can be effectively used to detect the state of inclination of the fuel surface. It suffices to use (doubly use), as the vehicle angle-of-inclination sensor and the acceleration sensor, sensors already installed beforehand in the vehicle, and it is not necessary to install a new vehicle angle-of-inclination sensor and acceleration sensor, so this can contribute to a reduction in weight and a reduction in cost.

DESCRIPTION OF EMBODIMENTS

FIG. 1AandFIG. 1Bshow a fuel tank system12pertaining to an embodiment. The fuel tank system12has a fuel tank14capable of holding fuel FE inside.

In the following description, arrow FR indicates the forward direction of a vehicle in which the fuel tank system12is installed, arrow RH indicates the vehicle rightward direction, and arrow UP indicates the upward direction.

The fuel tank14, as shown inFIG. 1B, is formed in a substantially rectangular shape as seen in a plan view. The fuel tank14is installed in the vehicle in such a way that the longitudinal direction of the fuel tank14coincides with the vehicle width direction (the direction of arrow RH and the opposite direction thereof) and the transverse direction of the fuel tank14coincides with the vehicle forward and rearward direction (the direction of arrow FR and the opposite direction thereof).

A filler pipe16is connected to the upper portion of the fuel tank14. An insertion opening22, into which a fuel nozzle34is inserted, is disposed in the upper portion of the filler pipe16. The insertion opening22is closed by a cap18, and the cap18is removed when refueling the fuel tank14.

A lid26is disposed in a panel20of the vehicle body. When refueling the fuel tank14, the lid26is opened as indicated by the long dashed double-short dashed line inFIG. 1Aso that attachment and removal of the cap18and insertion of the fuel nozzle34(seeFIG. 3AandFIG. 3B) into the insertion opening22are possible.

The lower portion of the filler pipe16is positioned on the lower side, in the vertical direction, of a later-described full level FL inside the fuel tank14.

Part of a vapor pipe36C (the section positioned on the fuel tank14side of a later-described rotating electromagnetic valve42) having a vapor outlet54C formed in its lower end is placed inside the fuel tank14. Additionally, a full-tank regulating valve28having a float28F with a lower specific gravity than the fuel (which floats on the fuel) is attached to the vapor outlet54C. Furthermore, a canister32is disposed outside the fuel tank14.

As shown inFIG. 3A, in a state in which the float28F is not floating on the fuel, the full-tank regulating valve28is open. In a state in which the full-tank regulating valve28is open, gas inside the fuel tank14is able to move through a communicating pipe30to the canister32. When the gas inside the fuel tank14moves to the canister32, fuel vapor included in the gas inside the fuel tank14is adsorbed by an adsorbent in the canister32. It should be noted that the section of the inside of the fuel tank14above the fuel surface will be called a “gas layer.” The gas layer section is a layer in which gas is present. For example, when the fuel surface goes down from the full level FL, the height of the gas layer section becomes higher.

In contrast to this, when the float28F floats on the fuel (rises) as shown inFIG. 1Ain accompaniment with an increase in the liquid level, the full-tank regulating valve28becomes closed. When the full-tank regulating valve28becomes closed, the gas inside the fuel tank14is unable to move to the canister32. When the fuel tank14is filled with more fuel from the fuel nozzle34in this state, the fuel with which the fuel tank14has been filled collects in the filler pipe16and the fuel surface inside the filler pipe16rises. Then, when the fuel inside the filler pipe16reaches the fuel nozzle34, the refueling is stopped by an auto stop mechanism in the fuel nozzle34.

As mentioned above, the section of the vapor pipe36C positioned inside the fuel tank14extends upward from the full-tank regulating valve28and is connected to the later-described rotating electromagnetic valve42. The rotating electromagnetic valve42and the canister32are connected to each other by a common pipe38. As described later, when the rotating electromagnetic valve42is switched to predetermined states, the full-tank regulating valve28is able to be communicated to the canister32by the vapor pipe36C, the rotating electromagnetic valve42, and the common pipe38.

One end of an open-to-atmosphere pipe40and one end of a purge pipe41are connected to the canister32. The other end of the open-to-atmosphere pipe40is open to the atmosphere. The other end of the purge pipe41is connected to an engine not shown in the drawings and can allow negative pressure in the engine to act on the canister32. Because of this negative pressure, atmospheric air is introduced from the open-to-atmosphere pipe40and the fuel vapor adsorbed by the adsorbent in the canister32is desorbed (purged).

As shown inFIG. 1B, the vapor outlet54C of the vapor pipe36C is located in a position in the center in the longitudinal direction (vehicle width direction) of the fuel tank14and near the center in the transverse direction, and the full-tank regulating valve28is disposed so as to open and close the vapor outlet54C. That is, the full-tank regulating valve28is also placed in a position in the center in the longitudinal direction (vehicle width direction) of the fuel tank14and near the center in the transverse direction (vehicle forward and rearward direction) of the fuel tank14. “Center” here includes a case where it is strictly the center in the longitudinal direction or the transverse direction of the fuel tank14as well as a range in which the float28F reliably rises and closes the full-tank regulating valve28because of the risen fuel surface when refueling the fuel tank14.

The rotating electromagnetic valve42is disposed outside the fuel tank14, in a position near an upper surface14U of the fuel tank14and above the full-tank regulating valve28.

As shown in detail inFIGS. 2A to 2C, the rotating electromagnetic valve42has a flat, round tube-shaped rotor housing44. A rotor46is placed inside the rotor housing44. The rotor46is rotated predetermined angles of rotation by plural coils48disposed in the rotor housing44. As shown inFIG. 1A,FIG. 3A,FIG. 4A, andFIG. 5A, the open/closed states of the rotating electromagnetic valve42(specifically, the angle of rotation of the rotor46) are controlled by a control device50.

As shown inFIG. 1AandFIG. 1B, a pair of branch pipes36A and36B are placed inside the fuel tank14. The branch pipes36A and36B each extend substantially parallel to the upper surface14U along the longitudinal direction of the fuel tank14from a position near the center to the neighborhoods of edge portions14E on both vehicle width direction sides of the fuel tank14.

Connecting holes52A,52B, and52C are formed in a lower surface44L (the surface near the fuel tank14) of the rotor housing44. One end of the branch pipe36A and one end of the branch pipe36B are connected to the connecting holes52A and52B, respectively, in the rotor housing44. Moreover, the upper end of the section of the vapor pipe36C on the fuel tank14side is connected to the connecting hole52C.

In the present embodiment, the communicating pipe30has the common pipe38on the canister32side and the plural (two) branch pipes36A and36B on the fuel tank14side. Additionally, the one rotating electromagnetic valve42is disposed in a branch portion30B at which the common pipe38branches into the plural branch pipes36A and36B.

Moreover, the section of the vapor pipe36C on the fuel tank14side branches from the branch portion30B. The common pipe38doubles as the section of the vapor pipe36C on the canister32side. That is, part of the vapor pipe36C is shared in common with part of the communicating pipe30.

As shown inFIG. 1AandFIG. 1B, the other end side of the branch pipe36A and the other end side of the branch pipe36B are bent downward, and open portions54A and54B are formed in the other ends. That is, the open portions54A and54B are spaced apart from each other in the longitudinal direction (vehicle width direction) of the fuel tank14and, particularly in the present embodiment, are located in positions close to the edge portions14E of the fuel tank14. Furthermore, the positions, in the upward and downward direction, of the open portions54A and54B are higher than the full level FL.

As shown inFIGS. 2(A) to 2(C), a common connecting hole52D is formed in an upper surface44U (the surface away from the fuel tank14) of the rotor housing44. The common pipe38is connected to the common connecting hole52D.

Individual communicating holes56A,56B, and56C corresponding to the connecting holes52A,52B, and52C, respectively, are formed in the rotor46. The individual communicating holes56A,56B, and56C merge in the upper portion of the rotor46to form a common communicating hole58. The common communicating hole58is communicated with the common connecting hole52D in the upper surface44U of the rotor housing44regardless of the angle of rotation of the rotor46.

In contrast to this, the positions of the individual communicating holes56A,56B, and56C are decided in such a way that the individual communicating holes56A,56B, and56C become communicated with any of the connecting holes52A,52B, and52C in the lower surface44L of the rotor housing44in accordance with the angle of rotation of the rotor46.

Specifically, for example, as shown inFIG. 3B, in a state in which the angle of rotation of the rotor46is a predetermined angle of rotation α1, the individual communicating hole56C is communicated with the connecting hole52C as shown inFIG. 1BandFIG. 2(A). However, the individual communicating hole56A is not communicated with the connecting hole52A, and the individual communicating hole56B is not communicated with the connecting hole52B. In this state, movement of the gas from the vapor pipe36C (the section on the fuel tank14A side) and to common pipe38is possible, but movement of the gas from the branch pipes36A and36B to the common pipe38is blocked.

It should be noted that inFIG. 1BorFIG. 3Bthe angle of rotation α1is 0 degrees as a reference of the angle of rotation of the rotor46.

In contrast to this, as shown inFIG. 4B, when the angle of rotation of the rotor46becomes a predetermined angle of rotation α2, the individual communicating hole56A is communicated with the connecting hole52A (seeFIG. 2(B)), but the individual communicating holes56B and56C are not communicated with the connecting holes52B and52C, respectively. In this state, movement of the gas from the branch pipe36A to the common pipe38is possible, but movement of the gas from the branch pipe36B to the common pipe38is blocked. Furthermore, movement of the gas through the vapor pipe36C is also blocked.

As shown inFIG. 5B, when the angle of rotation of the rotor46becomes a predetermined angle of rotation α3, the individual communicating hole56B is communicated with the connecting hole52B (seeFIG. 2(C)), but the individual communicating holes56A and56C are not communicated with the connecting holes52A and52C, respectively. In this state, movement of the gas from the branch pipe36B to the common pipe38is possible, but movement of the gas from the branch pipe36A to the common pipe38is blocked. Furthermore, movement of the gas through the vapor pipe36C is also blocked.

As shown inFIG. 1A, the vehicle in which the fuel tank14is installed has a vehicle angle-of-inclination sensor62that detects the angle of inclination of the vehicle and an acceleration sensor64that detects acceleration of the vehicle. In the fuel tank system12, data detected by the vehicle angle-of-inclination sensor62and the acceleration sensor64are sent to the control device50. An angle of inclination θ of the fuel surface can be calculated from information obtained by the vehicle angle-of-inclination sensor62and the acceleration sensor64. The vehicle angle-of-inclination sensor62and the acceleration sensor64are an example of a fuel inclination sensor60.

It should be noted that sensors installed beforehand in the vehicle can also be doubly used as the vehicle angle-of-inclination sensor62and the acceleration sensor64. The vehicle angle-of-inclination sensor62and the acceleration sensor64may also be installed as new sensors in the fuel tank system12.

The vehicle also has a lid switch66and a lid sensor68. Information obtained as a result of the lid switch66being operated is sent to the control device50. When the control device50receives this information, the control device50unlocks the lid26. Information about the open/closed state of the lid26is sent from the lid sensor68to the control device50. The control device50is able to determine that the lid26is open to refuel the fuel tank14.

Next, the action of the present embodiment will be described.

In the present embodiment, the control device50controls the open/closed state of the rotating electromagnetic valve42(the angle of rotation of the rotor46) on the basis of the control flow shown inFIG. 6.

First, in step S102the control device50judges whether or not the lid26has been opened. This judgment may be made on the basis of the information obtained as a result of the lid switch66being operated or on the basis of the information about the open/closed state of the lid26detected by the lid sensor68.

In a case where the control device50has judged in step S102that the lid26has not been opened, the control device50moves to step S108. Processes in step S108and thereafter will be described later.

In a case where the control device50has judged in step S102that the lid26has been opened, the control device50moves to step S104. In step S104the control device50drives the rotor46to rotate so that the angle of rotation of the rotor46of the rotating electromagnetic valve42becomes the predetermined angle of rotation α1. Because of this, as shown inFIG. 3BandFIG. 2(A), the individual communicating hole56C is communicated with the connecting hole52C, but the individual communicating hole56A is not communicated with the connecting hole52A, and the individual communicating hole56B is not communicated with the connecting hole52B.

In this state the cap18is removed by a filling station attendant, for example, and the fuel tank14is refueled as indicated by arrow F0inFIG. 3A. Until the fuel level in the fuel tank14reaches the full level FL, the full-tank regulating valve28is open. Furthermore, as shown inFIG. 3B, the state in which the individual communicating hole56C is communicated with the connecting hole52C is maintained. Consequently, the gas inside the fuel tank14moves through the vapor pipe36C (via the rotating electromagnetic valve42) to the canister32as indicated by arrows F1inFIG. 3A.

Then, as shown inFIG. 1A, when the fuel level inside the fuel tank14reaches the full level FL, the float28F floats on the fuel and the full-tank regulating valve28is closed. In this state also, the individual communicating hole56A is not communicated with the connecting hole52A, and the individual communicating hole56B is not communicated with the connecting hole52B. That is, the gas inside the fuel tank14is unable to move to the canister32. For this reason, the fuel with which the fuel tank14has been refueled collects inside the filler pipe16and the fuel surface inside the filler pipe16rises. Then, when the fuel inside the filler pipe16reaches the fuel nozzle34, the auto stop mechanism in the fuel nozzle34operates so that refueling is stopped.

It should be noted that in this state, as mentioned above, the paths of movement of the gas from the open portions54A and54B to the canister32are closed by the rotating electromagnetic valve42. Because the gas in the fuel tank14does not move via the branch pipes36A and36B to the canister32, over-refueling of the fuel tank14(refueling past the full level FL) can be prevented.

When refueling ends, the cap18is reattached by the filling station attendant, for example, and the lid26is closed. In step S106the control device50judges whether or not the lid26has been closed. In a case where the control device50has judged that the lid26has not been closed, the control device50returns to step S104. In a case where the control device50has judged that the lid26has been closed, the control device50moves to step S108.

In step S108the control device50detects the angle of inclination of the vehicle on the basis of the information from the vehicle angle-of-inclination sensor62. In step S110the control device50further detects the acceleration of the vehicle on the basis of the information from the acceleration sensor64. Additionally, in step S112the control device50calculates the angle of inclination θ of the fuel surface inside the fuel tank14.

It should be noted that in the present embodiment the angle of inclination θ of the fuel surface is the angle of the fuel surface measured using as a reference the fuel surface in a state in which the fuel tank14is level and with the counter-clockwise direction inFIG. 1Abeing positive.

That is, depending on the angle of inclination and the acceleration of the vehicle, there are cases where, for example, as shown inFIG. 4A, the angle of inclination θ becomes an angle of inclination θ1(a positive value) and the fuel leans rightward in the vehicle width direction. In this case, depending on the position of the fuel level, the open portion54A of the branch pipe36A on the left side in the vehicle width direction is positioned in the gas layer inside the fuel tank14, and the open portion54B of the branch pipe36B on the right side in the vehicle width direction and the full-tank regulating valve28in the substantial center in the vehicle width direction are positioned in the liquid fuel.

There are also cases where, as shown inFIG. 5A, conversely from the state shown inFIG. 4A, the angle of inclination θ becomes an angle of inclination θ2(a negative value) and the fuel leans leftward in the vehicle width direction. In this case, depending on the position of the fuel level, the open portion54B of the branch pipe36B on the right side in the vehicle width direction is positioned in the gas layer inside the fuel tank14, and the open portion54A of the branch pipe36A on the left side in the vehicle width direction and the full-tank regulating valve28in the substantial center in the vehicle width direction are positioned in the liquid fuel.

In step S114the control device50judges whether or not the angle of inclination θ of the fuel surface is greater than a threshold angle θA set beforehand. In a case where the control device50has judged that the angle of inclination θ is greater than the threshold angle θA (the state of the angle of inclination θ1shown inFIG. 4A), the control device50moves to step S116.

In step S116the control device50causes the rotor46of the rotating electromagnetic valve42to rotate so that its angle of rotation becomes the angle of rotation θ2. Because of this, as shown inFIG. 2(B)andFIG. 4B, the connecting hole52A and the individual communicating hole56A become communicated with each other. As indicated by arrows F2inFIG. 4A, movement of the gas from the branch pipe36A (the open portion54A) via the rotating electromagnetic valve42to the common pipe38is possible. The connecting hole52B and the individual communicating hole56B are not communicated with each other, so movement of the fuel (liquid) from the branch pipe36B (the open portion54B) to the common pipe38is blocked.

In a case where the control device50has judged in step S114that the angle of inclination θ of the fuel surface is equal to or less than the threshold angle θA, the control device50moves to step S118.

In step S118, the control device50judges whether or not the angle of inclination θ of the fuel is smaller than a threshold angle θB set beforehand. In a case where the control device50has judged that the angle of inclination θ is smaller than the threshold angle θB (the state of the angle of inclination θ2shown inFIG. 5A), the control device50moves to step S120.

In step S120, the control device50causes the rotor46of the rotating electromagnetic valve42to rotate so that its angle of rotation becomes the angle of rotation α3. Because of this, as shown inFIG. 2(C)andFIG. 5B, the connecting hole52B and the individual communicating hole56B become communicated with each other. As indicated by arrows F3inFIG. 5A, movement of the gas from the branch pipe36B (the open portion54B) via the rotating electromagnetic valve42to the common pipe38is possible. At the same time, the connecting hole52A and the individual communicating hole56A are not communicated with each other, so movement of the fuel (liquid) from the branch pipe36A (the open portion54A) to the common pipe38is blocked.

In a case where the control device50has judged in step S118that the angle of inclination θ of the fuel surface is equal to or less than the threshold angle θB, the control device50ends the flow.

As will be understood from the above description, in the fuel tank system12of the present embodiment, there are plural open portions (branch pipes) inside the fuel tank14. Additionally, the fuel inclination sensor60detects the angle of inclination θ of the fuel surface, and the open portions positioned in the gas layer inside the fuel tank14are communicated with the canister32to make it possible for the gas to move to the canister32. Consequently, in a case where, for example, the internal pressure of the fuel tank14has become high, even if the fuel surface is inclined, some of the gas moves to the canister32so that an excessive increase in the internal pressure of the fuel tank14can be prevented.

At the same time, when the fuel surface is inclined, the path leading from the open portion positioned in the liquid fuel inside the fuel tank14to the canister32is closed, so the liquid fuel can be prevented from flowing to the canister32.

Additionally, in the fuel tank system12of the present embodiment, the rotating electromagnetic valve42disposed outside the fuel tank14is used to prevent movement of the fuel from the open portions54A and54B to the canister32. For this reason, it is not necessary to dispose valves having floats (float valves) in the open portions54A and54B for the same purpose.

Here, a structure where float valves are disposed in all the open portions of the branch pipes will be supposed as a comparative example. In the structure of the comparative example, when the fuel is inclined, the float valve in the fuel closes, so movement of the liquid fuel to the canister can be prevented.

However, in the structure of the comparative example, if all the floats become immersed in the fuel and the open portions end up becoming closed, the gas inside the fuel tank cannot be moved to the canister when the internal pressure of the fuel tank rises.

In order to prevent this kind of situation in the structure of the comparative example, it is necessary to set the fuel surface low so that at least one float is positioned in the gas layer. However, the float housing of the float valve has a certain extent of height in order to ensure an amount of movement of the float in the upward and downward direction. Consequently, in the structure of the comparative example, the fuel surface ends up being set lower than the float housing having the certain extent of height, and it is difficult to set the fuel surface high. In short, in the structure of the comparative example, the fuel surface becomes set low, and the effective capacity of the fuel tank14(the amount of fuel that the fuel tank14can actually hold) becomes reduced.

Moreover, in a structure where float valves are disposed in all the open portions of the branch pipes like in the comparative example, when the float of the float valve positioned in the liquid fuel when the fuel surface is inclined moves up and down due to vibration of the vehicle, for example, there is the concern that the float valve will end up becoming opened.

In contrast to this, in the fuel tank system12of the present embodiment, it is not necessary to dispose valves having floats in the open portions54A and54B, and the open portions54A and54B can be set, for example, in positions near the upper surface14U of the fuel tank14. Furthermore, it is also not necessary to set low the liquid level when the fuel is inclined so that a float valve does not become opened when the float in the float valve moves up and down. In this way, in the present embodiment, the height of the fuel surface when the fuel surface is inclined can be raised to a position near the open portions54A and54B, so a large effective capacity can be ensured for the fuel tank14.

In the present embodiment, the full-tank regulating valve28is a valve having the float28F. That is, when the fuel level reaches the full level FL, movement of the gas from the fuel tank14to the canister32can be prevented by the simple action of the float28F floating on the fuel. For example, in a configuration where a liquid surface detection sensor detects the fuel surface and an electromagnetic valve or the like closes a vapor pipe when the liquid surface detection sensor has detected that the fuel level has reached a predetermined liquid level (full level), it is necessary to dispose an electromagnetic valve and to control the opening and closing of the electromagnetic valve. In contrast to this, in the present embodiment, a structure that can prevent movement of the gas from the fuel tank14to the canister32when the fuel tank14is full can be realized without having to detect, with a liquid level detection sensor or the like, that the level of the fuel inside the fuel tank14has reached the full level and having to control an electromagnetic valve.

The full-tank regulating valve28is disposed in a position in the center in the longitudinal direction of the fuel tank14when the fuel tank14is seen in a plan view. Consequently, even when the fuel tank14is inclined when refueling the fuel tank14, the effects of this inclination can be reduced to reduce variations in the amount of fuel inside the fuel tank14when the fuel tank14is full.

Furthermore, if the full-tank regulating valve28is placed near an edge portion14E of the fuel tank14, it is necessary to set the liquid surface low to ensure that the full-tank regulating valve28is not in the fuel (liquid) even in a case where the fuel surface is inclined in such a way that there is a gas layer on the side of the full-tank regulating valve28. By placing the full-tank regulating valve28in the center of the fuel tank14and ensuring that there is an open portion54A (or54B) near the edge portions14E like in the present embodiment, movement of the gas from the gas layer to the canister32when the fuel surface is inclined can be ensured by means of the open portion. Additionally, there is no problem even when the full-tank regulating valve28placed in the center is in the fuel when the fuel is inclined (even when the full-tank regulating valve28is closed), and the position of the liquid surface is not affected by the full-tank regulating valve28.

Additionally, valves having floats are not disposed in the open portions54A and54B of the branch pipes36A and36B. In this way, as long as there is a communicating pipe equipped with an open portion in which there is not a float valve, the liquid surface position when the fuel is inclined corresponding to the open portion in which there is not a float valve can be set high, and the effective capacity of the fuel tank14can also be increased.

Particularly in the present embodiment, the full-tank regulating valve28is disposed in a position near the center in the longitudinal direction, and the open portions54A and54B in which the full-tank regulating valve is not disposed are positioned on the edge portion sides in the longitudinal direction. For this reason, even when the fuel tank14is inclined when refueling the fuel tank14, the effects of this inclination of the fuel tank14can be reduced and it is possible for the full-tank regulating valve28to be closed (for the float28F to float on the fuel) by a predetermined refueling amount.

The common pipe38, which is part of the communicating pipe30, doubles as the part of the vapor pipe36C (the section from the rotating electromagnetic valve42to the canister32) that communicates the full-tank regulating valve28to the canister32. Consequently, compared to a structure where the vapor pipe36is disposed completely separately from the communicating pipe30, this can contribute to a reduction in weight and a reduction in the number of parts.

In the above embodiment, a structure having the plural (two) branch pipes36A and36B and the one common pipe38is described as an example of the communicating pipe30. In this structure, the part of the communicating pipe30from the open portions54A and54B to the canister32is shared in common by the common pipe38, so the number of parts can be reduced, which can contribute to a simplification of the structure and a reduction in weight.

Furthermore, in the above embodiment, the one rotating electromagnetic valve42is disposed in the branch portion30B of the communicating pipe30at which the common pipe38branches into the branch pipes36A and36B. Consequently, compared to a structure where a valve is disposed in each of the branch pipes36A and36B, the number of parts can be reduced, which can contribute to a simplification of the structure and a reduction in weight.

Moreover, the rotating electromagnetic valve42has the rotor46, and by simply adjusting the angle of rotation of the rotor46, the common pipe38can be communicated to either of the two branch pipes36A and36B. It suffices to control the angle of rotation of the one rotor46, and it is not necessary to control plural opening and closing valves, so control is easy.

The number of the open portions is not limited to the two described above, and the number of the communicating pipes (branch pipes) is also not limited to two. That is, three or more communicating pipes (branch pipes), each equipped with an open portion positioned higher than the full level FL, may also be disposed inside the fuel tank14. In a structure equipped with three or more branch pipes, it is also possible to communicate the communicating pipe to plural (not limited to one) branch pipes and also discommunicate the communicating pipe from the other branch pipes by engineering the internal structure of the electromagnetic valve and the control method.

Furthermore, a structure having two open portions positioned apart from each other in the vehicle width direction was described, but the open portions may also be positioned apart from each other in the vehicle forward and rearward direction, for example. In this case, the communicating pipes corresponding to the open portions can be opened and closed in correspondence to a case where the fuel surface is inclined in the vehicle forward and rearward direction.

Particularly in a structure having three or more open portions, it is also possible, for example, to arrange the open portions so that they correspond to inclinations of the fuel surface in the two directions of the vehicle width direction and the vehicle forward and rearward direction.

In the above embodiment, a structure having the vehicle angle-of-inclination sensor62and the acceleration sensor64was described as the fuel inclination sensor, but the fuel inclination sensor is not limited to these. For example, electrostatic capacitance sensors whose electrostatic capacitance changes in accordance with their state of contact with the fuel may be placed in plural places inside the fuel tank14, and the state of inclination of the fuel surface may be detected from the values of the electrostatic capacitance of the electrostatic capacitance sensors. However, in a structure using electrostatic capacitance sensors, the electrostatic capacitance sensors are located inside the fuel tank14, so this is disadvantageous in terms of ensuring a large effective capacity for the fuel tank14. In contrast to this, the vehicle angle-of-inclination sensor62and the acceleration sensor64used in the present embodiment are located outside the fuel tank14, so this is advantageous in terms of ensuring a large effective capacity for the fuel tank14. Moreover, by doubly using, in the fuel tank system12of the present embodiment, the vehicle angle-of-inclination sensor62and the acceleration sensor64that are already installed beforehand in the vehicle, the addition of new sensors is unnecessary, which can contribute to a reduction in weight and a reduction in cost.

The present application makes it possible for the gas to move from the fuel tank to the canister when the fuel surface in the fuel tank is inclined, and can ensure a large effective capacity for the fuel tank.

The disclosure of Japanese Patent Application No. 2015-235195, filed on Dec. 1, 2015, is incorporated in its entirety herein by reference.

All documents, patent applications, and technical standards mentioned in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, or technical standard were specifically and individually indicated to be incorporated by reference.