fuel cell vehicle

Abstract

To discharge a hydrogen gas properly during an emergency in a fuel cell vehicle.SOLUTION: A fuel cell vehicle 10 includes: a cab 11 provided with a driver seat; and a cab bridge 12 supporting the cab 11 and further includes: a fuel cell 2 which generates electric power through a chemical reaction between hydrogen and oxygen; a hydrogen tank 3 in which a hydrogen gas to be supplied to the fuel cell 2 is stored; a lower pipe 4 extending from the hydrogen gas 3; an upper pipe 5 extending in a vertical direction along a back surface 17 of the cab 11; and a connection part 6 which connects the lower pipe 4 with the upper pipe 5. The hydrogen gas flows into the lower pipe 4 from the hydrogen tank 3 during an emergency. The upper pipe 5 discharges the hydrogen gas which has flowed in the lower pipe 4 from an upper end 51 to the outside. The connection part 6 is fixed to the cab bridge 12.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This case relates to a fuel cell vehicle equipped with a hydrogen tank for storing hydrogen gas. [Background technology]

[0002] Conventionally, fuel cell vehicles equipped with fuel cells that generate electricity through a chemical reaction between hydrogen and oxygen (air) have been known. As a safety measure for such fuel cell vehicles in the event of a collision, it has been proposed to stop the supply of reactant gas to the fuel cell stack when it is determined that a collision has occurred, vent any unreacted gas remaining in the fuel cell stack to the outside, and shut off the power supply system of the fuel cell stack (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-335184 Summary of the Invention [Problem to be solved by the invention]

[0004] Fuel cell vehicles are equipped with a hydrogen tank that stores hydrogen gas to be supplied to the fuel cell. In the event of an emergency, such as a collision or fire, it is desirable to properly release (purge) the hydrogen gas in the hydrogen tank to the outside of the fuel cell vehicle in order to prevent unintended leakage of hydrogen gas from the hydrogen tank. Conventional technologies have room for improvement in terms of properly releasing hydrogen gas in such emergencies.

[0005] The fuel cell vehicle of the present invention was devised in view of the above-mentioned problems, and one of its objectives is to appropriately release hydrogen gas in an emergency. [Means for solving the problem]

[0006] The present invention has been made to solve at least part of the above problems, and can be realized as the following aspects or application examples. The fuel cell vehicle according to this application example is a fuel cell vehicle equipped with a cab in which a driver's seat is provided and a cab bridge supporting the cab, and includes: a fuel cell that generates electricity through a chemical reaction between hydrogen and oxygen; a hydrogen tank that stores hydrogen gas to be supplied to the fuel cell; a lower pipe extending from the hydrogen tank and through which the hydrogen gas flows from the hydrogen tank in an emergency; an upper pipe extending in the vertical direction along the back of the cab and releasing the hydrogen gas that has flowed through the lower pipe to the outside from its upper end; and a connecting part fixed to the cab bridge that connects the lower pipe and the upper pipe.

[0007] According to this application example, in an emergency, the hydrogen gas in the hydrogen tank can be released to the outside through the lower pipe and the upper pipe, which makes the hydrogen tank nearly empty, thereby preventing unintended leakage of hydrogen gas from the hydrogen tank. In addition, the upper pipe extends vertically along the back of the cab and releases hydrogen gas to the outside from its upper end, allowing the hydrogen gas to be released from the upper pipe in an appropriate direction (specifically, upwards) that has minimal impact on the surrounding area. Furthermore, by fixing the connection part to the cab bridge, which is unlikely to be damaged even in the event of a collision of the fuel cell vehicle, the connection rigidity of the lower pipe and the upper pipe can be ensured. Therefore, even in the event of a collision of the fuel cell vehicle, hydrogen gas can be more reliably released to the outside through the lower pipe and the upper pipe connected by the connection part. Therefore, according to this Application Example, hydrogen gas can be appropriately released in an emergency.

[0008] In fuel cell vehicles equipped with a cab, the rear structure (e.g., a luggage box) mounted behind the cab may be replaced depending on the application. Therefore, if the upper pipe were attached to the rear structure rather than to the back of the cab, it would be necessary to provide a dedicated upper pipe for each rear structure, or to replace the upper pipe every time the rear structure was replaced. In contrast, if the upper pipe is extended along the back of the cab as described above, a single upper pipe can be used as is even when the rear structure of the fuel cell vehicle is replaced. Therefore, the upper pipe can be shared among fuel cell vehicles that use various rear structures, which reduces costs. [Effects of the Invention]

[0009] According to the present invention, hydrogen gas can be appropriately released in an emergency in a fuel cell vehicle. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view schematically showing a main part of a fuel cell vehicle according to an embodiment. [Figure 2] FIG. 2 is a rear view schematically showing the main part of the fuel cell vehicle of FIG. [Figure 3] 2 is a cross-sectional view for explaining a connection portion of the fuel cell vehicle of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment (application example) of the present invention will be described with reference to the drawings. This embodiment is merely an example, and is not intended to exclude various modifications or applications of techniques not explicitly described in the following embodiments. Each configuration of this embodiment can be modified in various ways without departing from the spirit of the invention. Furthermore, it can be selected or combined as needed.

[0012] [1. Configuration] As shown in FIG. 1, a fuel cell vehicle 1 (hereinafter simply referred to as "vehicle 1") according to this embodiment is a truck equipped with a cab 11 in which a driver's seat is provided and a cab bridge 12 that supports the cab 11. The cab 11 is disposed at the front of the vehicle 1, and is disposed above a pair of side rails 13 that extend in the vehicle length direction (front-to-rear direction) D1. The cab 11 of this embodiment is configured to be able to tilt forward and upward about hinges 14 provided at the front ends of the side rails 13 as the center of rotation.

[0013] 2, each side rail 13 is a chassis frame having a channel-shaped cross section. The pair of side rails 13 are disposed spaced apart from each other in the vehicle width direction (left-right direction) D2. The cab bridge 12 has, for example, a gate shape (arch shape) and is bridged between a pair of side rails 13. Two lower end portions 15 of the cab bridge 12 are fixed to the outer sides of the side rails 13 in the vehicle width direction D2. On the other hand, a substantially U-shaped middle portion 16 of the cab bridge 12 extending between the two lower end portions 15 is positioned above the side rails 13. The cab bridge 12 of this embodiment supports the rear end portion of the cab 11 from below when it is in a tilted-down normal position.

[0014] The vehicle 1 includes a fuel cell 2 that generates electricity through a chemical reaction between hydrogen and oxygen, and a hydrogen tank 3 that stores hydrogen gas that is supplied to the fuel cell 2. The fuel cell 2 generates electricity through a chemical reaction between oxygen (O2) in the air taken in from outside the vehicle 1 and hydrogen (H2) in the hydrogen gas supplied from the hydrogen tank 3. The power generated by the fuel cell 2 is supplied to, for example, a battery or a motor (neither of which are shown). In this embodiment, the fuel cell 2 is disposed between a pair of side rails 13. The fuel cell 2 is supported on the side rails 13, for example, via a bracket (not shown).

[0015] The hydrogen tank 3 is formed, for example, in a cylindrical shape with both ends closed, and stores hydrogen gas under high pressure. In this embodiment, two hydrogen tanks 3 are illustrated as being arranged outboard of the side rails 13 in the vehicle width direction D2. More specifically, one hydrogen tank 3 is arranged to the left of the left side rail 13, and the other hydrogen tank 3 is arranged to the right of the right side rail 13. Each hydrogen tank 3 is supported, for example, by an adjacent side rail 13 via a bracket (not shown). Note that the number and arrangement of fuel cells 2 and hydrogen tanks 3 mounted on the vehicle 1 are not limited to those illustrated here.

[0016] The vehicle 1 includes a configuration for releasing (purging) hydrogen gas from the hydrogen tank 3 to the outside in the event of an emergency such as a collision or fire, which includes a lower pipe 4 extending from the hydrogen tank 3, an upper pipe 5 extending in the vehicle height direction (vertical direction) D3 along the back surface 17 of the cab 11, and a connection part 6 connecting the lower pipe 4 and the upper pipe 5. The "back surface 17 of the cab 11" here refers to the surface of the outer surface of the cab 11 that faces rearward of the vehicle 1.

[0017] The lower pipe 4 is a hollow member through which hydrogen gas flows from the hydrogen tanks 3 in an emergency. In this embodiment, the lower pipe 4 has two branches 41 extending from each of the two hydrogen tanks 3, and a junction 42 where the branches 41 join together. The two branches 41 extend from the front ends of the pair of hydrogen tanks 3 in directions approaching each other. The junction 42 extends upward from the point where the two branches 41 meet to near the middle part 16 of the cab bridge 12. In this embodiment, the junction 42 has a bent portion 43 that is bent in a V shape. The bent portion 43 increases the flexibility of the junction 42 and absorbs vibrations when the vehicle 1 is traveling or the cab 11 is tilted up.

[0018] A vent valve 20 that opens in an emergency is disposed at the connection between the branch 41 and the hydrogen tank 3. The vent valve 20 may be one that automatically opens in an emergency depending on the temperature, or one that is controlled by a control device to open in an emergency.

[0019] The upper pipe 5 extends upward from near the middle portion 16 of the cab bridge 12 and is fixed to the back surface 17 of the cab 11. The diameter (outer diameter and inner diameter) of the upper pipe 5 is larger than the diameter (outer diameter and inner diameter) of the joining portion 42 of the lower pipe 4. In this embodiment, the upper pipe 5 is disposed along the intake duct 18. The upper end portion 51 of the upper pipe 5 is set at a position slightly lower than the upper surface 19 of the cab 11. The upper pipe 5 releases hydrogen gas that has flowed through the lower pipe 4 from the upper end portion 51 to the outside (upward).

[0020] The lower pipe 4 and upper pipe 5 are made of a highly rigid material (for example, steel) because they are the components through which high-pressure hydrogen gas from the hydrogen tank 3 flows in an emergency. Hereinafter, upstream and downstream will be defined based on the flow direction of hydrogen gas in the lower pipe 4 and upstream pipe 5. In the event of an emergency for the vehicle 1, the hydrogen gas passes from the hydrogen tank 3 through the lower pipe 4 and upper pipe 5 in that order and is released to the outside of the vehicle 1.

[0021] The connecting portion 6 of this embodiment connects the upper end portion 44, which is the downstream end of the lower pipe 4, and the lower end portion 52, which is the upstream end of the upper pipe 5, at the middle portion 16 of the cab bridge 12. The connecting portion 6 is fixed to the cab bridge 12. The upper end portion 44 of the lower pipe 4 of this embodiment corresponds to the downstream end and upper end portion of the junction portion 42, and extends along the vehicle height direction D3.

[0022] As shown in FIG. 3, the connection portion 6 of this embodiment includes a connecting pipe 7 connected to the upper end 44 of the lower pipe 4, a lower rubber 8 fixed to the connecting pipe 7, an upper rubber 9 press-fitted into the lower end 52 of the upper pipe 5, and a bracket 10 fixed to the cab bridge 12 (not shown in FIG. 3). Like the lower pipe 4 and the upper pipe 5, the connecting pipe 7 is a member through which high-pressure hydrogen gas flows from the high-pressure tank 3, and is therefore formed of a highly rigid material (e.g., steel). Meanwhile, the lower rubber 8 and the upper rubber 9 are gaskets that fill the gap between the lower pipe 4 and the upper pipe 5 to prevent hydrogen gas leakage. The bracket 10 is formed of a rigid body similar to the cab bridge 12, for example.

[0023] The diameters (outer diameter and inner diameter) of the connecting pipe 7 are set to be approximately the same as the diameters (outer diameter and inner diameter) of the junction 42 of the lower pipe 4. The connecting pipe 7 of this embodiment is connected to the upper end 44 of the lower pipe 4 via a lock sleeve 61 that is female-threaded, and its upper half is disposed inside the upper pipe 5. In addition, to maintain the connection between the connecting pipe 7 and the upper end 44 of the lower pipe 4, the lock sleeve 61 and a flange 63 are detachably engaged with each other.

[0024] A cap 62 that prevents dust from entering is detachably attached to the upper end of the connecting pipe 7. The cap 62 is attached inside the upper pipe 5 so that it will come off the connecting pipe 7 due to the pressure of hydrogen gas that flows from the lower pipe 4 to the connecting pipe 7 in an emergency. Note that instead of being formed separately from the lower pipe 4 in this manner, the connecting pipe 7 may be formed integrally with the lower pipe 4. When the lower pipe 4 and the connecting pipe 7 are formed integrally, the lock sleeve 61 is not necessary.

[0025] The lower rubber 8 is formed, for example, in a cylindrical shape having a through-hole 81 in the center through which the connecting pipe 7 is inserted, and is fitted onto the outside of the connecting pipe 7. In this embodiment, the lower rubber 8 is supported from below by a flange 63 that extends radially outward from the outer circumferential surface of the connecting pipe 7.

[0026] The upper rubber 9 has a cylindrical press-fit portion 91 that is fitted into the upper pipe 5, an annular cover portion 92 that covers the edge (lower edge) of the lower end portion 52 of the upper pipe 5, and a lip portion 93 that extends radially inward from the cover portion 92 and abuts against the upper half of the connecting pipe 7. The lip portion 93 is slidable along the outer circumferential surface of the connecting pipe 7 and is provided so as to be able to come into and out of contact with the lower rubber 8.

[0027] When the cab 11 of the vehicle 1 is in a normal tilted-down position, the lip portion 93 of the upper rubber 9 comes into contact with the lower rubber 8. On the other hand, when the cab 11 of the vehicle 1 is in an inclined tilted-up position, the upper pipe 5 and the upper rubber 9 move forward and upward together with the cab 11, so that the lip portion 93 moves away from the lower rubber 8 while maintaining contact with the connecting pipe 7. In this way, the lower pipe 4 and the upper pipe 5 of this embodiment remain connected to each other via the connecting pipe 7, but are provided so as to be able to swing relatively in response to vibrations while the vehicle 1 is traveling and the tilt-up and tilt-down movements of the cab 11.

[0028] The bracket 10 of this embodiment is fixed to both the flange 63 and the intermediate portion 16 of the cab bridge 12 (see FIGS. 1 and 2). The method of fixing the bracket 10 is not particularly limited, and may be, for example, welding or fastening using bolts and nuts. The bracket 10 has an appropriate shape depending on the positional relationship between the connection portion 6 and the cab bridge 12. Note that, for example, if the flange 63 and the cab bridge 12 can be fixed directly (without the bracket 10), the bracket 10 may be omitted.

[0029] [2. Actions and Effects] Vehicle 1 is provided with a lower pipe 4 through which hydrogen gas flows from hydrogen tank 3 in an emergency, and an upper pipe 5 that releases the hydrogen gas that has flowed through lower pipe 4 to the outside, so that in an emergency, hydrogen gas inside hydrogen tank 3 can be released to the outside of vehicle 1 through lower pipe 4 and upper pipe 5. This brings hydrogen tank 3 close to empty, thereby preventing unintended leakage of hydrogen gas from hydrogen tank 3.

[0030] In addition, the upper pipe 5 extends in the vehicle height direction D3 along the back surface 17 of the cab 11 and releases hydrogen gas to the outside from its upper end portion 51, so that the hydrogen gas can be released from the upper pipe 5 in an appropriate direction (specifically, upwards) that has minimal impact on the surrounding area. Furthermore, since the connection part 6 connecting the lower pipe 4 and the upper pipe 5 is fixed to the cab bridge 12, the rigidity of the connection part 6 can be ensured. In other words, since the connection part 6 is fixed to the cab bridge 12, which is unlikely to be damaged even in the event of a collision of the vehicle 1, the rigidity of the connection between the lower pipe 4 and the upper pipe 5 can be ensured. Therefore, even in the event of a collision of the vehicle 1, hydrogen gas can be more reliably released to the outside through the lower pipe 4 and the upper pipe 5 connected by the connection part 6.

[0031] Therefore, the vehicle 1 is able to appropriately release hydrogen gas in an emergency. In particular, in a vehicle 1 in which the hydrogen tank 3 is located outboard of the side rails 13 in the vehicle width direction D2, preventing leakage of hydrogen gas from the hydrogen tank 3 in the event of a side collision is even more important. In contrast, the vehicle 1 of this embodiment appropriately releases hydrogen gas as described above, so unintended leakage of hydrogen gas can be suppressed even when the hydrogen tank 3 is located outboard of the side rails 13 in the vehicle width direction D2.

[0032] In a vehicle 1 equipped with a cab 11, the rear structure (e.g., a luggage box) mounted behind the cab 11 may be replaced depending on the use of the vehicle 1. For this reason, if the upper pipe were attached to the rear structure rather than to the back surface 17 of the cab 11, it would be necessary to provide a dedicated upper pipe for each rear structure, or to replace the upper pipe every time the rear structure was replaced. In contrast, if the upper pipe 5 is extended along the back surface 17 of the cab 11 as described above, a single upper pipe 5 can be used for multiple rear structures even when the rear structure of the vehicle 1 is replaced. Therefore, the upper pipe 5 can be shared among vehicles 1 to which various rear structures are applied, which reduces costs.

[0033] In this embodiment, the lower pipe 4 and the upper pipe 5, which are formed from separate members, are connected by the connecting portion 6 while being able to swing relative to each other, and therefore can absorb relative displacement between the lower pipe 4 and the upper pipe 5. This makes it possible to prevent damage to the lower pipe 4 and the upper pipe 5 due to vibrations while the vehicle 1 is traveling and the tilt-up and tilt-down operations of the cab 11. In particular, if the lower rubber 8 and the upper rubber 9 are provided, the relative displacement between the lower pipe 4 and the upper pipe 5 can be absorbed more smoothly, and therefore damage to the lower pipe 4 and the upper pipe 5 can be effectively prevented.

[0034] Furthermore, since the junction 42 of the lower pipe 4 in this embodiment has a bent portion 43, the bent portion 43 functions like a spring when the vehicle 1 is traveling or the cab 11 is tilted up or down, thereby absorbing vibrations of the junction 42. This also makes it possible to prevent damage to the lower pipe 4.

[0035] The cap 62 attached to the upper end of the connecting pipe 7 can prevent dust from entering the connecting pipe 7. Furthermore, if the cap 62 is attached to the connecting pipe 7 inside the upper pipe 5, the cap 62, which becomes detached from the connecting pipe 7 due to the pressure of hydrogen gas in an emergency, is more likely to remain inside the upper pipe 5. Therefore, compared to when a similar cap is attached to the upper end 51 of the upper pipe 5, the cap 62 can be prevented from flying out of the upper pipe 5 due to the pressure of hydrogen gas.

[0036] [3. Modifications] The configurations of the lower pipe 4 and the upper pipe 5 are not limited to the above examples. When only one hydrogen tank 3 is provided on the vehicle 1, the lower pipe 4 may be formed of a single hollow member extending from the single hydrogen tank 3 to the vicinity of the cab bridge 12, instead of having two branches 41. Furthermore, the upper pipe 5 may have its upper end 51 pointing slightly diagonally (diagonally upward), for example.

[0037] The configuration of the connection part 6 is not limited to the above example. The connection part 6 may be formed entirely from steel, as long as it is fixed to the cab bridge 12 and connects the lower pipe 4 and the upper pipe 5, and the lower rubber 8 and the cap 62 may be omitted. [Explanation of symbols]

[0038] 1 vehicle (fuel cell vehicle) 2 fuel cell 3 Hydrogen Tank 4 Lower pipe 5 Upper pipe 6 Connection 7 Connecting pipe 8 Lower rubber 9 Upper rubber 10 Bracket 11 Cab 12 Cab Bridge 13 Side rail 14 Hinge 15 Lower end of cab bridge 12 16 Middle part of cab bridge 12 17 Back 18 Intake duct 19 Top side 20 Vent valve 41 Branch 42 Junction 43 Bend 44 Upper end of lower pipe 4 51 Upper end of upper pipe 5 52 Lower end of upper pipe 5 61 Lock Sleeve 62 Cap 63 Tsuba 81 Through hole 91 Press-fit part 92 Cover 93 Lip D1 Vehicle length direction D2 Vehicle width direction D3 Vehicle height direction (vertical direction)

Claims

1. A fuel cell vehicle having a cab in which a driver's seat is provided and a cab bridge supporting the cab, a fuel cell that generates electricity through a chemical reaction between hydrogen and oxygen; a hydrogen tank for storing hydrogen gas to be supplied to the fuel cell; a lower pipe extending from the hydrogen tank and through which the hydrogen gas flows from the hydrogen tank in an emergency; an upper pipe extending in the vertical direction along the back surface of the cab and discharging the hydrogen gas that has flowed through the lower pipe to the outside from an upper end thereof; a connection portion fixed to the cab bridge and connecting the lower pipe and the upper pipe, The connection portion includes a connection pipe connected to an upper end of the lower pipe, a lower rubber fixed to the connection pipe, an upper rubber press-fitted to a lower end of the upper pipe, and a bracket fixed to the cab bridge. A fuel cell vehicle characterized by:

2. The lower pipe has a bent portion.

2. The fuel cell vehicle according to claim 1.

3. A cap is attached to the upper end of the connecting pipe.

3. The fuel cell vehicle according to claim 1 or 2.

Images