Vehicle and tank cover

Abstract

To prevent light-weight fuel gas discharged from a gas tank at an emergency from staying inside a tank cover.SOLUTION: A vehicle moves with gas lighter than air as the fuel. The vehicle includes a frame, a gas tank and a tank cover. The gas tank is mounted on the frame and stores the fuel. The tank cover is mounted on the frame and covers the gas tank. The tank cover includes a storage wall and a discharge guide passage. The storage wall constitutes a storage space of the gas tank. The discharge guide passage is arranged at a discharge direction downstream side oppositely to an injection port of a safety valve formed on the gas tank, and guides fuel gas discharged from the injection port to the outside of the tank cover.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a tank cover for covering a gas tank that stores gas fuel that is lighter than air. [Background technology]

[0002] Patent Document 1 discloses a moving body that obtains propulsion energy by receiving a supply of gas containing hydrogen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-137505 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses, for example, a vehicle driven by a hydrogen engine. However, there is no disclosure of how the supply source of hydrogen gas to the hydrogen engine is configured.

[0005] In order to supply a machine with a lightweight fuel gas, a gas tank filled with the lightweight fuel gas at high pressure is used. The gas tank may be covered with a tank cover to protect the gas tank from external impacts, for example.

[0006] Gas tanks have a function to automatically release fuel gas from the gas tank in an emergency. However, it is undesirable for a large amount of fuel gas to be released from the gas tank into the narrow space inside the tank cover and remain there.

[0007] The present disclosure has been made in consideration of the above circumstances, and its purpose is to prevent lightweight gas fuel released from a gas tank in an emergency from remaining inside a tank cover that covers a gas tank that stores gas fuel that is lighter than air. [Means for solving the problem]

[0008] The problem to be solved by the present disclosure is as described above. Next, the means for solving this problem and the effects thereof will be described.

[0009] According to a first aspect of the present disclosure, there is provided a vehicle having the following configuration. That is, the vehicle travels using gas that is lighter than air as fuel. The vehicle has a frame, a gas tank, and a tank cover. The gas tank is attached to the frame and stores the fuel. The tank cover is attached to the frame and covers the gas tank. The tank cover includes a storage wall and a discharge guide passage. The storage wall forms a storage space for the gas tank. The discharge guide passage is disposed downstream in the discharge direction opposite a discharge port of a safety valve formed in the gas tank, and guides gas fuel discharged from the discharge port to the outside of the tank cover.

[0010] According to a second aspect of the present disclosure, there is provided a tank cover having the following configuration. That is, the tank cover covers a gas tank that stores gas fuel that is lighter than air. The tank cover includes an accommodation wall and a discharge guide passage. The accommodation wall forms an accommodation space for the gas tank. The discharge guide passage is disposed downstream in a discharge direction opposite a discharge port of a safety valve formed in the gas tank. The discharge guide passage guides gas fuel discharged from the discharge port to the outside of the tank cover.

[0011] As a result, the gas tank can be protected by preventing the gas tank from being exposed by the storage wall. Also, when the lightweight fuel gas is released from the release port, the discharge guide passage guides the lightweight fuel gas to the outside of the tank cover, realizing a structure in which the lightweight fuel gas is less likely to remain in the storage space. Effect of the Invention

[0012] According to the present disclosure, it is possible to prevent lightweight gas fuel released from a gas tank in an emergency from remaining inside the tank cover. [Brief description of the drawings]

[0013] [Figure 1] 1 is a side view showing an overall configuration of a motorcycle according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a rear perspective view showing the tank cover of the first embodiment. [Diagram 3] FIG. 2 is a cross-sectional view showing the tank cover of the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a muffler according to a second embodiment. [Diagram 5] FIG. 11 is a perspective view showing a muffler according to a third embodiment. [Figure 6] FIG. 13 is a perspective view showing a muffler according to a fourth embodiment. [Figure 7] FIG. 13 is a cross-sectional view showing a tank cover according to a fifth embodiment. [Figure 8] FIG. 13 is a cross-sectional view showing a tank cover according to a sixth embodiment. [Figure 9] FIG. 13 is a cross-sectional view showing a tank cover according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a side view showing an overall configuration of a motorcycle 1 according to an embodiment of the present disclosure. Fig. 2 is a perspective view showing a tank cover 25 of the first embodiment. Fig. 3 is a cross-sectional view showing the tank cover 25 of the first embodiment.

[0015] The motorcycle (saddle-type vehicle, vehicle) 1 of this embodiment includes a frame 3, a front wheel 6, a rear wheel 7, and a steering handle 8. The frame 3, the front wheel 6, the rear wheel 7, and the steering handle 8 form a part of a vehicle body 2.

[0016] A driver drives the motorcycle 1 while straddling the body 2. In the following description, unless otherwise specified, the terms front, rear, left, and right mean the front, rear, left, and right as seen by the driver while riding the motorcycle 1. The left-right direction corresponds to the vehicle width direction, and the front-rear direction corresponds to the vehicle length direction.

[0017] The frame 3 is a strength component that serves as the framework of the vehicle body 2, and is made of, for example, metal pipes. The frame 3 supports an engine (lightweight fuel gas internal combustion engine) 22 that serves as a drive source for propelling the motorcycle 1.

[0018] The engine 22 functions as a power unit that drives the rear wheels 7, which are driving wheels. The engine 22 burns a lightweight gas fuel to rotate a crankshaft (not shown) to obtain power. In this specification, lightweight gas means a gas that is lighter per unit volume than air at room temperature. In this embodiment, hydrogen is used as the fuel for the engine 22, but light gases such as methane and ammonia may also be used. The number of cylinders in the engine 22 is arbitrary, but in this embodiment, a multiple-cylinder engine 22 is used. The driving force generated by the engine 22 is changed in speed by a transmission (not shown) and transmitted to the rear wheels 7 via the drive chain 12.

[0019] A seat 14 for a driver to sit in is provided on the upper part of the vehicle body 2. A steering wheel 8 operated by the driver is provided on the upper front part of the vehicle body 2.

[0020] A head pipe 15 is provided at the front of the frame 3. A front wheel 6 is supported on the head pipe 15 via a front fork 16. The rider can turn the front wheel 6 by operating a steering handle 8. A swing arm 17 is supported at the lower part of the central front-rear portion of the frame 3 so as to protrude rearward. The rear wheel 7 is rotatably supported at the tip of the swing arm 17.

[0021] A gas tank 21 is fixed to the rear of the frame 3. The gas tank 21 may be directly attached to the frame 3, or may be indirectly attached via another member such as a support member. Hydrogen gas, which is fuel, is stored in a compressed state in the gas tank 21. In this embodiment, a pair of gas tanks 21 are provided on the left and right, but the number of gas tanks 21 is arbitrary. Each gas tank 21 is formed in a cylindrical shape, and is disposed with its axial direction facing the front-rear direction. Each gas tank 21 is disposed behind the seat 14.

[0022] A fuel collecting device 26 is attached to the rear of the frame 3. The fuel collecting device 26 is disposed between the left and right gas tanks 21. The fuel collecting device 26 collects fuel supplied from each of the two gas tanks 21 via pipes (not shown) into one system. The fuel collecting device 26 is provided with a valve (not shown) that switches between supplying and cutting off fuel. The fuel collecting device 26 and the engine 22 are connected by a fuel supply pipe 27. Hydrogen gas is supplied from the fuel collecting device 26 to the engine 22 via the fuel supply pipe 27.

[0023] A hollow tank cover 25 is attached to the frame 3 so as to cover the gas tank 21. The tank cover 25 may be attached directly to the frame 3, or may be attached indirectly via another member such as a support member. The tank cover 25 may have any shape, but in this embodiment, it is formed into a cylindrical shape with both axial ends closed. The tank cover 25 has a storage wall 30, and this storage wall 30 forms a space for storing the gas tank 21. Hereinafter, this space may be referred to as the storage space 31. The tank cover 25 protects the gas tank 21 inside from external impacts.

[0024] The tank cover 25 is configured to be openable and closable. For example, by configuring the tank cover 25 to be divided into upper and lower parts, the storage space 31 can be opened to the outside, and the gas tank 21 can be replaced.

[0025] An emergency release nozzle 21b is provided at an appropriate position on the gas tank 21. In this embodiment, the emergency release nozzle 21b is disposed at the rear end of the gas tank 21 (the end farther from the seat 14), but is not limited thereto. The emergency release nozzle 21b is connected to an emergency release valve (safety valve) (not shown) provided on the gas tank 21. Therefore, the emergency release nozzle 21b corresponds to a release port. The emergency release valve is configured as a pressure relief valve. The emergency release valve is normally closed, but is automatically opened when the pressure in the gas tank 21 abnormally rises and exceeds a predetermined allowable pressure. As a result, hydrogen gas can be released to the outside of the gas tank 21 through the emergency release nozzle 21b.

[0026] The gas tank 21 has a valve portion 21a protruding in the axial direction at the center of one axial end face. The gas tank 21 is set inside the tank cover 25 with the valve portion 21a facing rearward. The emergency release nozzle 21b is disposed in the valve portion 21a. The emergency release nozzle 21b is disposed so as to release hydrogen gas downward. A discharge guide passage 32 connected to the emergency release nozzle 21b is formed in the lower portion of the tank cover 25. This makes it possible to prevent the release of hydrogen gas from being blocked by the tank cover 25. The discharge guide passage 32 is disposed outside the accommodation space 31 and is partitioned from the accommodation space 31 by the accommodation wall 30. The discharge guide passage 32 is disposed on the rear side (the side farther from the seat 14) of the tank cover 25 in correspondence with the position of the emergency release nozzle 21b.

[0027] As shown in Fig. 2, the discharge guide passage 32 includes a slit-shaped recess 33. The recess 33 is formed in a vertically elongated shape at the bottom of the rear end surface 35 of the tank cover 25. The recess 33 is formed across both the lower surface 34 and the rear end surface 35 of the tank cover 25, leaving both surfaces open. When the motorcycle 1 is viewed from the rear as shown in Fig. 2, the recess 33 is formed in an inverted V shape so that its left-right width increases toward the lower surface 34 of the tank cover 25.

[0028] The discharge guide passage 32 is disposed below the emergency discharge nozzle 21b of the gas tank 21. The lower side can be rephrased as the downstream side in the direction in which hydrogen gas is discharged from the emergency discharge nozzle 21b. The discharge guide passage 32 is disposed to face the emergency discharge nozzle 21b in the vertical direction. A through hole 36 is formed in the storage wall 30 of the tank cover 25 at a position corresponding to the ceiling part of the recess 33. The through hole 36 is provided to penetrate the ceiling part of the recess 33 in the vertical direction. The hydrogen gas discharged downward from the emergency discharge nozzle 21b of the gas tank 21 passes through the through hole 36 and is introduced into the recess 33. Most of the hydrogen gas ejected into the inside of the recess 33 is discharged downward from the lower end of the recess 33 as shown by the arrow A1 in FIG. 3, and the remainder is discharged backward from the rear end as shown by the arrow A2, etc. Since the through hole 36 is airtightly closed by the surrounding portion of the emergency discharge nozzle 21b, the air or hydrogen gas inside the recess 33 does not enter the inside of the storage space 31. The airtight seal can be achieved, for example, by a seal ring (not shown).

[0029] Hydrogen gas is lighter per unit volume than air. Taking this into consideration, a sloping surface 37 is formed at the rear end of the ceiling portion of the recess 33, sloping upward as it approaches the rear end surface 35 of the tank cover 25. This allows the hydrogen gas in the recess 33 to be smoothly discharged to the outside from the rear end surface 35 side along the sloping surface 37 by utilizing the buoyancy effect of the hydrogen gas, as shown by arrow A3 in FIG. 3. In this way, the vicinity of the above-mentioned ceiling portion (including the sloping surface 37) among the open portions of the recess 33 functions as an outlet 44 for discharging the hydrogen gas floating toward the upper part of the discharge guide passage 32 rearward from the rear end of the tank cover 25.

[0030] A muffler 23, which is an example of a vehicle part and an exhaust part, is disposed on one of the left and right sides of the rear wheel 7. The muffler 23 is located below one of the pair of tank covers 25 disposed on the left and right sides.

[0031] The muffler 23 is connected to the engine 22 via an exhaust pipe 28. An exhaust outlet 24 is formed at the rear end of the muffler 23. Exhaust gas generated by burning hydrogen gas in the engine 22 passes through the exhaust pipe 28 and the muffler 23, and is discharged to the outside from the exhaust outlet 24. A sound-absorbing structure is formed inside the muffler 23, which reduces the exhaust noise generated when the exhaust gas is discharged to the outside. In this way, the muffler 23 functions as an exhaust sound-absorbing device.

[0032] In a motorcycle 1 equipped with a hydrogen gas engine 22, unburned hydrogen gas may be discharged from the engine 22. The unburned hydrogen gas passes through the exhaust pipe 28 and the muffler 23 and is discharged from the exhaust outlet 24. Since hydrogen gas has a buoyancy effect, if the tank cover 25 is located above the muffler 23, the hydrogen gas may remain near the underside 34 of the tank cover 25 for a long period of time.

[0033] In this regard, in this embodiment, the discharge guide passage 32 is configured to guide the gas fuel to the outside of the tank cover 25 not only through the lower opening but also through the rear opening (including the outlet 44). Therefore, the gas fuel in the discharge guide passage 32 can be smoothly discharged.

[0034] Consider the case where hydrogen gas is discharged downward from the emergency discharge nozzle 21b. Most of the hydrogen gas is discharged downward from the discharge guide passage 32 as shown by arrow A1. However, since the gas pressure in the gas tank 21 is reduced just before the discharge is completed, the momentum of the hydrogen gas discharged from the emergency discharge nozzle 21b is weak and it may not be discharged to the outside from the lower end of the discharge guide passage 32. However, the hydrogen gas remaining inside the discharge guide passage 32 is smoothly discharged to the outside from the tank cover 25 via the rear outlet 44.

[0035] As shown in Fig. 2, in each of the pair of gas tanks 21, the emergency release nozzle 21b is disposed at a different position in the left-right direction from the rear wheel 7. Correspondingly, each recess 33 is disposed at a different position in the left-right direction from the rear wheel 7. Wall portions of the tank cover 25 are disposed on both sides of each recess 33. These walls can encourage the hydrogen gas discharged from the emergency release nozzle 21b to flow straight down when viewed from the back. This can prevent the hydrogen gas discharged in an emergency from hitting the rear wheel 7 or the like and diffusing over a wide area.

[0036] As described above, the motorcycle 1 of this embodiment travels using hydrogen gas, which is lighter than air, as fuel. The motorcycle 1 has a frame 3, a gas tank 21, and a tank cover 25. The gas tank 21 is attached to the frame 3 and stores fuel. The tank cover 25 is attached to the frame 3 and covers the gas tank 21. The tank cover 25 has a storage wall 30 and a discharge guide passage 32. The storage wall 30 forms a storage space 31 for the gas tank 21. The discharge guide passage 32 is disposed downstream in the discharge direction, facing the emergency discharge nozzle 21b formed in the gas tank 21. The discharge guide passage 32 guides the gas fuel discharged from the emergency discharge nozzle 21b to the outside of the tank cover 25.

[0037] As a result, the gas tank 21 can be protected by preventing exposure of the gas tank 21 by the storage wall 30. Furthermore, when hydrogen gas is released from the emergency release nozzle 21b, the hydrogen gas is guided to the outside of the tank cover 25 by the discharge guide passage 32, so that a structure in which hydrogen gas is less likely to remain in the storage space 31 can be realized.

[0038] In the motorcycle 1 of this embodiment, the discharge direction of the gas fuel from the emergency discharge nozzle 21b faces downward. The discharge guide passage 32 guides the gas fuel downward in the accommodation space 31.

[0039] As a result, in the event of an emergency, hydrogen gas is released below the motorcycle 1, preventing the released hydrogen gas from reaching a location far from the motorcycle 1. A space for releasing hydrogen gas in the event of an emergency is secured by the discharge guide passage 32 below the accommodation space 31, while a structure can be realized in which hydrogen gas is less likely to accumulate in this discharge guide passage 32.

[0040] In the motorcycle 1 of this embodiment, the discharge guide passage 32 is formed with an outlet 44 for discharging hydrogen gas floating up toward the upper part of the discharge guide passage 32 to the rear of the tank cover 25.

[0041] As a result, even if hydrogen gas floats to the upper part of the discharge guide passage 32, the hydrogen gas is discharged from the outlet 44. This makes it possible to prevent hydrogen gas from accumulating within the discharge guide passage 32.

[0042] In the motorcycle 1 of this embodiment, the wall surfaces constituting the discharge guide passage 32 include a ceiling surface. A part of the ceiling surface forms an inclined surface 37 that slopes outward (rearward) from the tank cover 25 as it approaches the top.

[0043] This allows the hydrogen gas to be effectively discharged to the outside of the tank cover 25.

[0044] In the motorcycle 1 of this embodiment, the discharge guide passage 32 includes a recess 33 formed across a lower surface 34 and a rear end surface 35 of the tank cover 25 .

[0045] This allows the hydrogen gas in the discharge guide passage 32 to be smoothly discharged to the outside of the tank cover 25 through the opening of the recess 33 .

[0046] In the motorcycle 1 of this embodiment, the recess 33 is formed in the shape of a slit extending in the up-down direction.

[0047] This allows the hydrogen gas to move smoothly up and down within the discharge guide passage 32 .

[0048] The motorcycle 1 of this embodiment is a saddle-ride type vehicle having a seat 14 on which a rider sits. The tank cover 25 is disposed rearward of the seat 14. A discharge guide passage 32 is disposed on the side of the tank cover 25 farther from the seat 14 (rearward).

[0049] As a result, hydrogen gas is released from the emergency release nozzle 21b located away from the driver, preventing any effect on the driver's driving operation.

[0050] In the motorcycle 1 of this embodiment, the hydrogen gas discharged from the emergency discharge nozzle 21b into the discharge guide passage 32 is discharged below the tank cover 25 at a different position relative to the rear wheel 7 in the vehicle width direction.

[0051] This makes it possible to prevent the hydrogen gas discharged from the emergency discharge nozzle 21b from hitting the rear wheel 7 and bouncing back. Therefore, it is possible to prevent the hydrogen gas from reaching a place far away from the motorcycle 1.

[0052] Next, a second embodiment of the present disclosure will be described. In the following description of this embodiment, the same or similar members as those in the previous embodiment are denoted by the same reference numerals in the drawings, and descriptions thereof may be omitted.

[0053] In the tank cover 25a of this embodiment shown in Fig. 4, the direction of hydrogen gas sprayed downward from the emergency release nozzle 21b is changed by providing an inclined guide surface 38 in the recess 33. With such a configuration of the discharge guide passage 32, the hydrogen gas is discharged obliquely toward the space behind the muffler 23, as shown by arrow A4, so as to avoid the muffler 23 located directly below the tank cover 25a. The tank cover 25a of this embodiment can prevent the hydrogen gas released in an emergency from hitting the muffler 23 and diffusing over a wide area.

[0054] As described above, in the tank cover 25a of this embodiment, the discharge guide passage 32 guides hydrogen gas to a position below the tank cover 25a that avoids the muffler 23.

[0055] This makes it possible to prevent the hydrogen gas discharged from the emergency discharge nozzle 21b from bouncing back off the muffler 23. Therefore, it is possible to prevent the hydrogen gas from reaching a location far away from the motorcycle 1.

[0056] Next, a third embodiment of the present disclosure will be described.

[0057] In the tank cover 25b of this embodiment shown in Fig. 5, the left and right width of the recess 33 constituting the discharge guide passage 32 is formed to be large. The left and right width of the recess 33 is constant regardless of the distance from the lower surface 34. Except for the shape of the recess 33, the configuration of the second embodiment is similar to that of the first embodiment.

[0058] Next, a fourth embodiment of the present disclosure will be described.

[0059] In the tank cover 25c of this embodiment shown in Fig. 6, the left-right width of the recess 33 constituting the discharge guide passage 32 is larger than that of the third embodiment described above. As a result, the recess 33 is formed over the entire left-right width of the tank cover 25c. Unlike the first and second embodiments, the tank cover 25c of this embodiment does not have walls that face each other in the left-right direction across the recess 33.

[0060] Next, a fifth embodiment of the present disclosure will be described.

[0061] The tank cover 25d of this embodiment shown in FIG. 7 includes a discharge tube (tubular portion) 39. The discharge tube 39 is disposed so as to vertically penetrate the storage wall 30 located on the lower surface 34 of the tank cover 25d. The discharge tube 39 can be formed, for example, in a cylindrical shape. The emergency discharge nozzle 21b is connected to the upper end of the discharge tube 39. The upper end of the discharge tube 39 is airtightly closed by the surrounding portion of the emergency discharge nozzle 21b. The lower end of the discharge tube 39 protrudes downward from the lower surface 34 of the tank cover 25d. An opening (open portion) 40 is formed at the lower end of the discharge tube 39. The discharge tube 39 may be formed integrally with the storage wall 30.

[0062] In this embodiment, a discharge guide passage 32 is formed inside the discharge tube 39. This discharge guide passage 32 extends linearly along the direction of hydrogen gas discharged from the emergency discharge nozzle 21b. Therefore, this discharge guide passage 32 can allow the hydrogen gas discharged from the emergency discharge nozzle 21b to move in the discharge direction, while preventing the hydrogen gas from moving in a direction intersecting the discharge direction.

[0063] A cap (closing member) 41 is removably attached to the lower end of the discharge tube 39. The cap 41 is formed in a short cylindrical shape with one end closed. The cap 41 is made of an elastic member such as rubber, and is fixed so as to cover the lower end of the discharge tube 39. This makes it possible to close the opening 40.

[0064] The inner diameter of the cap 41 is slightly smaller than the outer diameter of the discharge tube 39. The cap 41 is attached so as to cover the outer periphery of the discharge tube 39 while being elastically deformed. Therefore, the cap 41 is fixed to the discharge tube 39 by the restoring force of the cap 41. The holding force by this restoring force is weaker than, for example, the holding force by bolt fixing.

[0065] In this configuration, under normal circumstances, the opening at the bottom end of the exhaust tube 39 is closed by the cap 41. Therefore, even if the unburned gas discharged from the exhaust outlet 24 of the muffler 23 floats up to the vicinity of the underside 34 of the tank cover 25d, it does not enter the inside of the exhaust tube 39 and remain there for a long period of time.

[0066] When hydrogen gas is sprayed downward from the emergency release nozzle 21b, the pressure in the discharge guide passage 32 increases. When the pressure increases to a predetermined level, the cap 41 falls off the discharge tube 39, exposing the opening 40 at the bottom end of the discharge tube 39. The hydrogen gas discharged from the emergency release nozzle 21b then passes through the discharge guide passage 32 inside the discharge tube 39 and is discharged downward from the opening 40.

[0067] In this embodiment, the cap 41 is attached only to the tank cover 25d on the same side in the left-right direction as the muffler 23, out of the pair of left and right tank covers 25d. The cap 41 may close the opening 40 in both the left and right tank covers 25d.

[0068] As described above, in the tank cover 25d of this embodiment, the discharge guide passage 32 extends along the discharge direction of the gas fuel from the emergency discharge nozzle 21b. The discharge guide passage 32 allows the hydrogen gas discharged from the emergency discharge nozzle 21b to move in the discharge direction, while preventing the hydrogen gas from moving in a direction intersecting the discharge direction.

[0069] This makes it possible to promote the discharge of hydrogen gas to the outside of the rear end face 35 by utilizing the momentum of the hydrogen gas released from the emergency release nozzle 21b.

[0070] In the tank cover 25d of this embodiment, the discharge guide passage 32 is formed inside a discharge tube 39 that extends from the periphery of the emergency discharge nozzle 21b to an opening 40 that opens to the outside of the tank cover 25d.

[0071] This allows the discharge guide passage 32 to be realized with a simple structure.

[0072] In the tank cover 25d of this embodiment, a downward opening 40 is formed in the tank cover 25d at the downstream end of the discharge guide passage 32. The opening 40 is closed by a cap 41. The cap 41 releases the closure of the opening 40 when the internal pressure of the discharge guide passage 32 becomes higher than a predetermined level.

[0073] As a result, when an exhaust part (e.g., muffler 23) is disposed below tank cover 25d, even if unburned hydrogen gas discharged from muffler 23 floats up near the bottom of tank cover 25d, the hydrogen gas can be prevented from entering and remaining in discharge guide passage 32 through opening 40 of tank cover 25d. Closing of opening 40 by cap 41 is automatically released when gas tank 21 discharges hydrogen gas into discharge guide passage 32 in an emergency, so that opening 40 can be prevented from interfering with the discharge.

[0074] Next, a sixth embodiment of the present disclosure will be described.

[0075] In the tank cover 25e of this embodiment, a conical discharge taper portion 42 is provided instead of the discharge tube 39 shown in Fig. 7. The discharge taper portion 42 is formed so that the inner diameter increases toward the lower surface 34 of the tank cover 25e. The upper end of the discharge taper portion 42 is airtightly closed by the surrounding portion of the emergency discharge nozzle 21b. The lower end of the discharge taper portion 42 forms an opening 40 in the lower surface of the tank cover 25e. The cap 41 described in the fifth embodiment is not provided in this embodiment.

[0076] A gas vent passage 43 is formed so as to connect the vicinity of the upper end of the inner wall of the discharge taper portion 42 with the rear end surface 35 of the tank cover 25e. Similar to the aforementioned inclined surface 37, the gas vent passage 43 is inclined so as to become upward as it approaches the rear end surface 35 of the tank cover 25. The gas vent passage 43 forms an outlet 44 in the rear end surface 35 of the tank cover 25e.

[0077] In this embodiment, the internal space of the discharge taper portion 42 and the gas vent passage 43 form the discharge guide passage 32 .

[0078] 8, a partition member 51 may be provided below the opening 40. This partition member 51 is disposed so as to separate the space between the tank cover 25e and the muffler 23. The partition member 51 is disposed so as to face the opening 40 in the up-down direction. With this configuration, it is possible to prevent unburned hydrogen gas discharged from the exhaust outlet 24 of the muffler 23 from entering the opening 40.

[0079] As described above, in the tank cover 25e of this embodiment, the discharge guide passage 32 is formed with the outlet 44 for discharging hydrogen gas floating toward the upper part of the discharge guide passage 32 to the outside of the tank cover 25e.

[0080] In this embodiment, the motorcycle 1 includes a muffler 23 disposed below the tank cover 25e. A partition member 51 that blocks the opening 40 from the muffler 23 is provided below the opening 40 that the discharge guide passage 32 forms in the lower surface 34 of the tank cover 25e.

[0081] This makes it possible to prevent unburned hydrogen gas that is discharged from the muffler 23 and floats up from entering the discharge guide passage 32 through the opening 40.

[0082] Next, a seventh embodiment of the present disclosure will be described.

[0083] In a tank cover 25f of this embodiment shown in Fig. 9, a connection recess 45 and a gas vent pipe 46 are provided instead of the gas vent passage 43 (Fig. 8) of the sixth embodiment. The connection recess 45 is formed so as to be recessed rearward from the vicinity of the upper end of the inner wall of the discharge tapered portion 42.

[0084] A gas vent pipe 46 is provided so as to connect to the ceiling surface of the connection recess 45. The gas vent pipe 46 penetrates the storage wall 30 of the tank cover 25f to enter the storage space 31, and further penetrates the storage wall 30 to protrude obliquely upward from the tank cover 25f. An outlet 44 is formed at the tip of the gas vent pipe 46.

[0085] Consider a case in which, in this configuration, unburned hydrogen gas discharged from exhaust outlet 24 of muffler 23 floats up and enters the inside of exhaust tapered section 42 through opening 40. However, this hydrogen gas enters gas vent pipe 46 from the upper end of the inside of exhaust tapered section 42, via connecting recess 45, and is smoothly discharged from outlet 44.

[0086] The shape of the path of the gas vent pipe 46 is arbitrary, but in this embodiment, it has a curved portion that bends to one side, either left or right, midway. If the gas vent pipe 46 is made of a flexible material, this is preferable because it increases the freedom to lay out the path for releasing hydrogen gas.

[0087] Although the preferred embodiment of the present disclosure has been described above, the above configuration can be modified, for example, as follows. A single modification may be made, or multiple modifications may be made in any combination.

[0088] The direction of release of hydrogen gas from the emergency release nozzle 21b is not limited to a vertically downward direction, but may be changed to an obliquely downward direction, a horizontal direction, an obliquely upward direction, a vertically upward direction, etc. Correspondingly, the slit-shaped recess 33 shown in Fig. 2 can be changed so as to extend, for example, in an oblique direction or a horizontal direction instead of in the vertical direction.

[0089] The hydrogen gas discharged from the emergency discharge nozzle 21b and discharged to the outside of the gas tank 21 via the discharge guide passage 32 may hit some part of the motorcycle 1.

[0090] The inclined surface 37 may be omitted, and the entire ceiling surface of the recess 33 may be horizontal. The entire ceiling surface of the recess 33 may be inclined.

[0091] In the first to fourth embodiments, the recess 33 may be formed to be open, for example, downward or on one of the left and right sides. In this case, the inclined surface 37 may be formed to be upward as it approaches the open side of the recess 33 on one of the left and right sides.

[0092] In the fifth embodiment, the cap 41 may be formed to be inserted into the opening 40 instead of being placed on the lower end of the discharge tube 39 from the outside. Instead of the cap 41, the opening 40 may be closed by a valve made of, for example, a leaf spring. Instead of the cap 41, the opening 40 may be closed by a membrane that breaks when the pressure in the discharge guide passage 32 reaches or exceeds a certain level.

[0093] The shape of the gas tank 21 is not limited to a cylindrical shape and may be any suitable shape. The tank cover 25 may also be any suitable shape, such as a polygonal prism.

[0094] The gas tank 21 and the tank cover 25 may be disposed, for example, at the front of the motorcycle 1 instead of at the rear.

[0095] The partition member 51 of the sixth embodiment may be provided to block the lower opening of the discharge guide passage 32 relative to the muffler 23 in other embodiments.

[0096] In the seventh embodiment, the gas vent pipe 46 may be directly connected to the internal space of the exhaust taper portion 42 .

[0097] Together with the gas tank 21, a fixing frame for mounting the gas tank 21 to the frame 3 may be housed in the tank cover 25.

[0098] The gas tank 21 may be provided to supply hydrogen gas to a fuel cell instead of the engine 22 .

[0099] The tank cover described above can be applied not only to two-wheeled motor vehicles 1 (saddle-type vehicles, lean vehicles), but also to a wide range of vehicles such as three-wheeled vehicles, four-wheeled vehicles, ships, aircraft, etc. Vehicles include moving bodies that move without a human on board.

[0100] The tank cover of the present disclosure is not limited to a mobile body, but may be applied to a gas tank that supplies fuel to a stationary lightweight fuel gas internal combustion engine. For example, the tank cover may be applied to a gas tank that supplies fuel to an internal combustion engine as a power generation device or a hydraulic drive device that does not have a mobile propulsion source. [Explanation of symbols]

[0101] 1. Motorbike (vehicle) 3 Frame 7 Rear wheel 21 Gas Tank 21b Emergency discharge nozzle (discharge port) 25,25a~25f Tank Cover 30 Containment Wall 31 Containment Space 32 Discharge guide passage 39 Discharge tube (tubular part) 40 aperture 41 Cap (closing member) 44 Exit

Claims

1. A vehicle that runs on gas that is lighter than air, A frame, a gas tank attached to the frame and configured to store the fuel; a tank cover attached to the frame and covering the gas tank; having The tank cover is A storage wall that defines a storage space of the gas tank; a discharge guide passage disposed downstream in a discharge direction opposite to a discharge port of a safety valve formed in the gas tank, the discharge guide passage configured to guide the gas fuel discharged from the discharge port to the outside of the tank cover; A vehicle equipped with:

2. 2. The vehicle of claim 1, The discharge direction of the gas fuel from the discharge port faces downward, The discharge guide passage guides the gas fuel downwardly into the storage space.

3. 3. A vehicle as claimed in claim 2, The discharge guide passage guides the gas fuel to a position below the tank cover that avoids vehicle parts.

4. 2. The vehicle of claim 1, The discharge guide passage extends along the discharge direction of the gas fuel from the discharge port, and allows the gas fuel discharged from the discharge port to move in the discharge direction while preventing movement in a direction intersecting the discharge direction.

5. 2. The vehicle of claim 1, An outlet is formed in the discharge guide passage for discharging the gas fuel floating toward an upper portion of the discharge guide passage to the outside of the tank cover.

6. 6. A vehicle as claimed in claim 5, The wall surface that defines the discharge guide passage has a ceiling surface, At least a portion of the ceiling surface has a slope that slopes outwardly of the tank cover as it approaches the top.

7. 2. The vehicle of claim 1, The discharge guide passage includes a recess formed across a lower surface of the tank cover and a surface adjacent to the lower surface and facing in a different direction.

8. 8. A vehicle as claimed in claim 7, The recess is formed in a slit shape extending in the vertical direction.

9. 2. The vehicle of claim 1, The discharge guide passage is formed inside a cylindrical portion extending from the periphery of the discharge port to an opening of the tank cover that is open to the outside.

10. 10. A vehicle as claimed in claim 9, A downward opening is formed in the tank cover at the downstream end of the discharge guide passage, The opening is closed by a closing member, The closing member releases the closure of the opening when the internal pressure of the discharge guide passage becomes higher than a predetermined value.

11. 2. The vehicle of claim 1, The vehicle is a saddle-type vehicle having a seat for a driver, The tank cover is disposed rearward of the seat, The discharge guide passage is disposed on a side of the tank cover away from the seat.

12. 12. A vehicle as claimed in claim 11, The hydrogen gas discharged from the discharge port into the discharge guide passage is discharged below the tank cover at a position that differs in a vehicle width direction relative to a rear wheel of the vehicle.

13. 13. A vehicle as claimed in claim 12, comprising: An exhaust part is provided below the tank cover, an outlet is formed in the discharge guide passage for discharging the gas fuel floating toward an upper portion of the discharge guide passage to the outside of the tank cover, a partition member that blocks an opening formed in the lower surface of the tank cover by the discharge guide passage and that blocks the opening from the exhaust parts,

14. A tank cover for covering a gas tank that stores gas fuel that is lighter than air, A storage wall that defines a storage space of the gas tank; a discharge guide passage disposed downstream in a discharge direction opposite to a discharge port of a safety valve formed in the gas tank, the discharge guide passage configured to guide the gas fuel discharged from the discharge port to the outside of the tank cover; Equipped with a tank cover.

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