Fuel cell systems and electric assist vehicles

Abstract

To provide a fuel cell system and an electric assist vehicle that allow for easy replacement of the canister. [Solution] The fuel cell system comprises a fuel cell, a canister that supplies fuel gas to the fuel cell, and a holder 32 having a cylindrical peripheral wall 49 that holds the outer surface of the canister. The holder 32 has an insertion port into which the canister is inserted and a connecting portion to which the canister is detachably connected when the canister is inserted from the insertion port, and is mounted on the housing 35 so as to be rotatable between a first position in which the canister is used and a second position in which the canister is replaced, with a pivot axis J1 extending in a direction intersecting the axial direction of the peripheral wall 49 as the pivot center.

Description

Technical Field

[0001] The present invention relates to a fuel cell system and an electric assist vehicle.

Background Art

[0002] Patent Document 1 discloses a fuel cell electric assist bicycle. Such a fuel cell electric assist bicycle includes a frame, a fuel cell, and a hydrogen tank. The lower pipe in the frame includes a tank holding portion that holds the hydrogen tank in its internal space and a lid portion. The hydrogen tank includes a tank body and a pressure regulating valve. The tank body is filled with compressed hydrogen.

[0003] The pressure regulating valve is a valve provided to reduce the pressure of hydrogen in the tank body and supply it to the fuel cell. The fuel cell generates an electrochemical reaction and generates electricity when hydrogen from the hydrogen tank and oxygen in the atmosphere are supplied. The electric power generated by the fuel cell is used to assist in the operation of the fuel cell electric assist bicycle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the above-mentioned fuel cell electric assist bicycle has a configuration in which the pressure regulating valve of the hydrogen tank and the fuel cell are connected by a flexible hose. Therefore, when replacing the hydrogen tank, first, the hose is removed from the pressure regulating valve of the old hydrogen tank, and then the old hydrogen tank is taken out from the tank holding portion. After that, a new hydrogen tank is held in the tank holding portion, and then the hose is connected to the pressure regulating valve of the new hydrogen tank to replace the hydrogen tank.

[0006] Therefore, in the aforementioned fuel cell electric assist bicycle, it is necessary to switch the hydrogen tank to a hose when replacing the hydrogen tank, so there is room for improvement in making hydrogen tank replacement easier. [Means for solving the problem]

[0007] The following describes the means and effects of solving the above problems. A fuel cell system that solves the above problems comprises a fuel cell, a canister that supplies fuel gas to the fuel cell, and a holder having a cylindrical peripheral wall that holds the outer circumferential surface of the canister, wherein the holder has an insertion port into which the canister is inserted, and a connecting portion to which the canister is detachably connected when the canister is inserted from the insertion port, and is mounted on a mounting portion so as to be rotatable between a first position in which the canister is used and a second position in which the canister is replaced, with a pivot axis extending in a direction intersecting the axial direction of the peripheral wall as the pivot center.

[0008] With the above configuration, the canister can be easily replaced by rotating the holder from the first position to the second position and then replacing the canister held in the holder with a new one. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a side view of the electric assist vehicle according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram of the fuel cell system in the electric assist vehicle shown in Figure 1. [Figure 3] Figure 3 is a perspective view showing the holder with the rotating mechanism attached. [Figure 4] Figure 4 is a perspective view of Figure 3 from a different angle. [Figure 5] Figure 5 is a plan view showing the state when the holder is in the first position. [Figure 6]Figure 6 is a plan view showing the state when the holder is in the second position. [Figure 7] Figure 7 is a perspective view showing the holder when it is locked by the locking mechanism. [Figure 8] Figure 8 is a perspective view of the locking mechanism shown in Figure 7. [Figure 9] Figure 9 is a side view of the electric assist vehicle according to the second embodiment. [Figure 10] Figure 10 is an enlarged view of the main part of Figure 9. [Figure 11] Figure 11 is a perspective view showing the holder supported by a pair of shaft bolts and locked by a locking mechanism. [Figure 12] Figure 12 is a side view showing the state when the bearing portion of the holder is inserted into the insertion hole of the housing. [Figure 13] Figure 13 is a side view showing the state when the holder is in the first position. [Figure 14] Figure 14 is a side view showing the state when the holder is in the second position. [Modes for carrying out the invention]

[0010] (First Embodiment) The first embodiment will be described below with reference to the drawings. <Electric-assisted vehicle 11> As shown in Figure 1, the electric assist vehicle 11 is configured to move by adding an assist driving force from the motor 12 to the human power driving force from the rider. The electric assist vehicle 11 is, for example, an electric assist bicycle. The electric assist vehicle 11 comprises a frame 13, a front fork 14, a handlebar 15, a front wheel 16, a rear wheel 17, a saddle 18, and a drive unit 19.

[0011] Frame 13 has a head tube 20, a seat tube 21, a top tube 22, a down tube 23, seat stays 24, and chain stays 25. The head tube 20 extends substantially in the vertical direction. The seat tube 21 extends substantially in the vertical direction along the head tube 20 behind the head tube 20. The top tube 22 connects the upper end of the head tube 20 and the upper end of the seat tube 21.

[0012] The down tube 23 connects the lower end of the head tube 20 and the lower end of the seat tube 21. The seat stays 24 extend rearward from the upper end of the seat tube 21. The chain stays 25 extend rearward from the lower end of the seat tube 21. The lower end of the seat stays 24 and the rear end of the chain stays 25 are connected to each other. The frame 13 is constituted by, for example, welding a plurality of pipes having a circular cross-section.

[0013] The front fork 14 is rotatably supported about an axis extending vertically by the head tube 20. The handle 15 is provided at the upper end of the front fork 14. The front wheel 16 is rotatably supported at the lower end of the front fork 14. The rear wheel 17 is rotatably supported with respect to the connecting portion of the seat stays 24 and the chain stays 25.

[0014] The saddle 18 is provided at the upper end of the seat tube 21. The drive unit 19 is fixed to the frame 13 below the connecting portion of the seat tube 21 and the down tube 23. The drive unit 19 has a crankshaft 26, a pair of crank arms 27, a pair of pedals 28, and a motor 12.

[0015] The crankshaft 26 extends in the vehicle width direction (left - right direction). A pair of crank arms 27 extend respectively in a direction perpendicular to the crankshaft 26 from both ends of the crankshaft 26 in the longitudinal direction. A pair of pedals 28 are respectively fixed to the ends of the pair of crank arms 27. The crankshaft 26 is connected to the rear wheel 17 via a chain (not shown). The manual driving force applied by the occupant acting on the pedal 28 is transmitted to the rear wheel 17 via the above - mentioned chain. The motor 12 is connected to the crankshaft 26 via a transmission member (not shown). The motor 12 applies an assist driving force to the crankshaft 26.

[0016] <Fuel cell system 29> As shown in FIG. 2, the electric assist vehicle 11 includes a fuel cell system 29. The fuel cell system 29 includes a fuel cell 30, a canister 31, a holder 32, a compressor 33, and a pump 34. The fuel cell 30 supplies power to the motor 12. The canister 31 supplies fuel gas to the fuel cell 30. The holder 32 houses the canister 31. The compressor 33 supplies oxidant gas to the fuel cell 30. The pump 34 supplies a coolant such as water to the fuel cell 30.

[0017] As shown in FIGS. 1 and 2, the fuel cell system 29 includes a housing 35 that houses the fuel cell 30, the compressor 33, and the pump 34. The housing 35 has, for example, two divided bodies (not shown) divided in the vehicle width direction. The fuel cell 30, the compressor 33, and the pump 34 are fixed to one of the two divided bodies. The housing 35 is fixed to the frame 13 by connecting the two divided bodies to each other with the frame 13 sandwiched in the vehicle width direction.

[0018] The housing 35 has an opening 36 that penetrates the housing 35 in the vehicle width direction and extends along the down tube 23. A holder 32 housing the canister 31 is positioned in the opening 36 so as to extend along the down tube 23. The holder 32 is attached at its lower end to one of the two divided parts of the housing 35 via a pivot mechanism 37.

[0019] In this example, the mounting portion to which the holder 32 is attached is formed by the housing 35. The holder 32 is rotatably supported by a pivoting mechanism 37. The holder 32 is exposed from the housing 35. The pivoting mechanism 37 is housed in the housing 35 and is fixed to the housing 35.

[0020] <Fuel cell 30> As shown in Figure 2, the fuel cell 30 has a fuel gas supply port 38 into which fuel gas is supplied, a fuel gas outlet 39 into which fuel gas is discharged, an oxidant gas supply port 40 into which oxidant gas is supplied, and an oxidant gas outlet 41 into which oxidant gas is discharged. At one end of the fuel cell 30 in the vehicle width direction, the fuel gas supply port 38 and the oxidant gas outlet 41 are arranged in this order from top to bottom.

[0021] At the other end of the fuel cell 30 in the vehicle width direction, an oxidizer gas supply port 40 and a fuel gas outlet 39 are arranged in this order from top to bottom. The fuel gas supply port 38 is connected via a first gas pipe 42 to a connection portion 43 that protrudes from the bottom of the holder 32. The oxidizer gas supply port 40 is connected via a second gas pipe 44 to a compressor 33.

[0022] The fuel cell 30 includes a power generation unit 45 having a membrane electrode assembly (not shown). The power generation unit 45 is located in the center of the fuel cell 30. Fuel gas supplied from the fuel gas supply port 38 passes through the power generation unit 45 and is discharged to the outside of the fuel cell 30 from the fuel gas outlet 39. Oxidizer gas supplied from the oxidizer gas supply port 40 passes through the power generation unit 45 and is discharged to the outside of the fuel cell 30 from the oxidizer gas outlet 41. In the power generation unit 45, electricity is generated by an electrochemical reaction between the fuel gas and the oxidizer gas. The fuel gas is, for example, hydrogen gas. The oxidizer gas is, for example, air.

[0023] The fuel cell 30 has a coolant supply port 46 into which coolant is supplied and a coolant discharge port 47 into which the coolant is discharged. The coolant supply port 46 is located at the lower end of the fuel cell 30 in the center in the vehicle width direction. The coolant discharge port 47 is located at the upper end of the fuel cell 30 in the center in the vehicle width direction. The coolant flows inside the fuel cell 30 to cool the fuel cell 30, which generates heat in conjunction with the power generation of the power generation unit 45.

[0024] <Canister 31> As shown in Figure 2, the canister 31 is substantially cylindrical in shape. A discharge section 48 for discharging hydrogen gas is provided at one end of the canister 31 in the longitudinal direction. The discharge section 48 is detachably connected to the connection section 43 when the canister 31 is housed in the holder 32. That is, the discharge section 48 is connected to the first gas piping 42 via the connection section 43. The canister 31 contains a hydrogen storage alloy that absorbs and releases hydrogen gas. The canister 31 supplies hydrogen gas released from the hydrogen storage alloy to the fuel cell 30 via the discharge section 48, the connection section 43, and the first gas piping 42.

[0025] When the hydrogen storage alloy releases hydrogen gas, the temperature of the hydrogen storage alloy decreases due to an endothermic reaction. As the temperature of the hydrogen storage alloy decreases, the pressure inside the canister 31 decreases, which reduces the amount of hydrogen gas released by the hydrogen storage alloy. In this embodiment, the temperature decrease of the hydrogen storage alloy is suppressed by circulating a coolant in the circulation channel between the fuel cell 30 and the holder 32, thereby performing heat exchange between the fuel cell 30 and the hydrogen storage alloy via the coolant.

[0026] <Holder 32> As shown in Figures 1 and 2, the holder 32 has a cylindrical peripheral wall 49 that holds the outer circumferential surface of the canister 31. The holder 32 is positioned along the down tube 23 with the axial direction of the peripheral wall 49 inclined with respect to both the horizontal and vertical directions. The discharge portion 48 of the canister 31 housed in the holder 32 is directed diagonally downward and rearward in the electric assist vehicle 11.

[0027] The holder 32 comprises a cylindrical inner cylinder 50, a cylindrical outer cylinder 51, and a lid 52. The inner cylinder 50 has an insertion opening 53 at its upper end into which the canister 31 is inserted. The inner cylinder 50 accommodates the canister 31 when it is inserted into the inner cylinder 50 from the insertion opening 53, with the canister 31 being inserted from the discharge end 48 side. When the canister 31 is inserted into the inner cylinder 50 from the insertion opening 53, the discharge end 48 of the canister 31 is detachably connected to the connection end 43. When the inner cylinder 50 accommodates the canister 31, the upper end of the canister 31 protrudes from the insertion opening 53.

[0028] The outer cylinder 51 houses the inner cylinder 50. The upper ends of the outer cylinder 51 and the inner cylinder 50 are flush with each other. The lid 52 is attached to the upper end of the outer cylinder 51, covering the upper end of the canister 31 that protrudes from the insertion opening 53 at the upper end of the inner cylinder 50. The peripheral wall 49 of the holder 32 is made up of the inner cylinder 50 and the outer cylinder 51. The inner cylinder 50, the outer cylinder 51, and the lid 52 are made of a metal material such as an aluminum alloy.

[0029] The inner surface of the inner cylinder 50 is in contact with the outer surface of the canister 31 housed inside it over its entire circumference. A male thread (not shown) is formed around the entire circumference of the outer surface of the upper end of the outer cylinder 51. An insertion passage 54 is provided in the center of the lower end of the outer cylinder 51 through which the connecting portion 43 is inserted. The insertion passage 54 communicates with the lower opening 55 of the inner cylinder 50 into which the connecting portion 43 is fitted.

[0030] The lid 52 is roughly dome-shaped. The inner circumferential surface of the lid 52 has a female thread (not shown) that engages with the male thread of the outer cylinder 51. The lid 52 is detachably attached to the outer cylinder 51 by the engagement of the female thread of the lid 52 with the male thread of the outer cylinder 51. When the lid 52 is attached to the outer cylinder 51, it closes the insertion opening 53 of the inner cylinder 50.

[0031] <Internal flow path 56> As shown in Figure 2, the peripheral wall 49 has an internal flow path 56 that extends in the axial direction of the peripheral wall 49. The internal flow path 56 includes a cylindrical space provided around the entire circumference inside the peripheral wall 49. That is, when the inner cylinder 50 is housed in the outer cylinder 51, the internal flow path 56 is formed between the outer circumferential surface of the inner cylinder 50 and the inner circumferential surface of the outer cylinder 51.

[0032] The upper end of the internal flow path 56 is sealed by a first seal ring 57 positioned between the outer circumferential surface of the inner cylinder 50 and the inner circumferential surface of the outer cylinder 51. The lower end of the internal flow path 56 is sealed by a second seal ring 58 positioned between the outer circumferential surface of the inner cylinder 50 and the inner circumferential surface of the outer cylinder 51.

[0033] The internal flow path 56 has an inlet 59 and an outlet 60. The inlet 59 and outlet 60 open to the upper surface of the peripheral wall 49. The inlet 59 and outlet 60 penetrate the outer cylinder 51 in the thickness direction.

[0034] The inlet 59 introduces the coolant discharged from the coolant outlet 47 of the fuel cell 30 into the internal flow path 56. The outlet 60 leads the coolant from the internal flow path 56 to the coolant supply port 46 of the fuel cell 30. In Figure 2, the coolant is shown with dot hatching. The inlet 59 is located at the upper end of the internal flow path 56. The inlet 59 is connected to the coolant outlet 47 via the first cooling pipe 61.

[0035] The outlet 60 is located at the lower end of the internal flow path 56. That is, the outlet 60 is located below the inlet 59. The outlet 60 is connected to the coolant supply port 46 via the second cooling pipe 62. A pump 34 is provided midway along the second cooling pipe 62 to pump the coolant from the outlet 60 side toward the coolant supply port 46 side. Therefore, the coolant circulates through the inside of the fuel cell 30, including the coolant supply port 46 and the coolant discharge port 47, and through the circulation path including the first cooling pipe 61, the internal flow path 56 of the holder 32, and the second cooling pipe 62, driven by the pump 34.

[0036] <Rotation mechanism 37> As shown in Figures 3 and 4, the rotating mechanism 37 includes a first mounting member 64 attached to the lower end of the holder 32, for example by a screw 63, and a second mounting member 65 attached to the housing 35 (see Figure 1) by a screw 63, for example, while rotatably supporting the first mounting member 64. That is, the holder 32 is attached to the housing 35 (see Figure 1) at its lower end via the first mounting member 64 and the second mounting member 65.

[0037] The first mounting member 64 has a rectangular fixing plate 66 fixed to the lower surface of the holder 32, and a pair of substantially rectangular connecting plates 67 integrally formed at both the upper and lower ends of the fixing plate 66. In other words, the first mounting member 64 has a substantially U-shaped plate form. The fixing plate 66 is positioned perpendicular to the axial direction of the peripheral wall 49 of the holder 32. The pair of connecting plates 67 are positioned perpendicular to the fixing plate 66.

[0038] The pair of connecting plates 67 face each other in a direction perpendicular to the axial direction of the peripheral wall 49 of the holder 32. A U-shaped notch 68 is formed at the right end of the pair of connecting plates 67. The rear side surface of the notch 68 is composed of a flat surface 69 extending in the vehicle width direction (left-right direction). The front side surface of the notch 68 is composed of an inclined surface 70 that is inclined forward with respect to the vehicle width direction. The flat surface 69 and the inclined surface 70 face each other in the axial direction of the peripheral wall 49 of the holder 32.

[0039] The second mounting member 65 has a pair of substantially rectangular mounting blocks 71 that extend in the vehicle width direction. The left ends of the outer surfaces of the pair of mounting blocks 71 are in contact with the approximate center of the inner surface of the pair of connecting plates 67. The approximate center of the pair of connecting plates 67 and the left ends of the pair of mounting blocks 71 are rotatably connected by bolts 72 and nuts 73, respectively. The right ends of the pair of mounting blocks 71 are fixed to the housing 35 (see Figure 1) by, for example, screws 63.

[0040] The first mounting member 64 is rotatable together with the holder 32 to which the first mounting member 64 is attached, with the bolt 72 and nut 73 as the pivot point. That is, the holder 32 is rotatable with respect to a pivot axis J1 that extends perpendicular (intersecting) to the axial direction of the peripheral wall 49 of the holder 32. In this example, the pivot axis J1 is the same as the axis of the bolt 72 and nut 73. On the outer surfaces of the pair of mounting blocks 71, protrusions 74 are formed as an example of stoppers that extend linearly in the vehicle width direction. The left ends of the protrusions 74 of the pair of mounting blocks 71 are inserted into notches 68 of the pair of connecting plates 67.

[0041] The range of rotation of the first mounting member 64 and the holder 32 with respect to the pivot axis J1 is limited by the contact between the flat surface 69 or the inclined surface 70 of the notch 68 and the protrusion 74. The first mounting member 64 and the holder 32 rotate with respect to the pivot axis J1 between a first position (shown in Figure 5) where the flat surface 69 contacts the protrusion 74 and a second position (shown in Figure 6) where the inclined surface 70 contacts the protrusion 74. In other words, the protrusion 74 has the function of stopping the holder 32 in the first position when the flat surface 69 contacts it, and stopping the holder 32 in the second position when the inclined surface 70 contacts it.

[0042] As shown in Figures 1, 2, and 5, the first position is where the holder 32 fits into the opening 36 of the housing 35, and where the canister 31 housed in the holder 32 is used. As shown in Figures 1, 2, and 6, the second position is where the lid 52 of the holder 32 protrudes to the right from the opening 36 of the housing 35, and where the canister 31 housed in the holder 32 is replaced.

[0043] <Locking mechanism 75> As shown in Figures 1, 7, and 8, a locking mechanism 75 for locking the holder 32 in a first position is mounted above the lid 52 inside the housing 35. The locking mechanism 75 comprises a locking portion 76 and a lock release portion 77 integrally formed with the locking portion 76.

[0044] The locking mechanism 76 comprises a bottomed rectangular box-shaped case 79 having a protruding opening 78, and a claw member 80 housed in the case 79 so that its tip can extend and retract from the protruding opening 78. A spring (not shown) is arranged inside the case 79 to bias the claw member 80 so that its tip always protrudes from the protruding opening 78.

[0045] The protruding opening 78 faces an insertion recess 81 formed in the center of the lid 52 of the holder 32 in the first position. When the tip of the claw member 80 is inserted into the insertion recess 81, the rotation of the holder 32 from the first position to the second position is inhibited. In other words, the holder 32 is locked by the locking mechanism 75. The right side surface 82 of the tip of the claw member 80 is inclined such that the protrusion height from the protruding opening 78 increases towards the left side. The left side surface 83 of the tip of the claw member 80 is flat.

[0046] The unlocking section 77 is cylindrical with a bottom and has a keyhole 84 at its bottom into which a key (not shown) can be inserted and removed. The keyhole 84 is exposed on the outer surface of the housing 35. When the key is inserted into the keyhole 84 of the locking mechanism 75, the key engages with the claw member 80. When the key is turned in a predetermined direction in this state, the claw member 80 moves against the biasing force of the spring, and the tip of the claw member 80 is retracted into the case 79 through the protruding opening 78.

[0047] As a result, the tip of the claw member 80 comes out of the insertion recess 81. In other words, the locking mechanism 75 releases the holder 32. In this state, rotation of the holder 32 from the first position to the second position is permitted.

[0048] <Operation of the First Embodiment> To replace the used canister 31, first, insert the key (not shown) into the keyhole 84 and turn it to release the lock on the holder 32 by the locking mechanism 75 in the first position of the holder 32. Next, rotate the holder 32 from the first position to the second position. At this time, the inclined surface 70 comes into contact with the protrusion 74, causing the holder 32 to stop in the second position. Then, as shown in Figure 6, the cover 52 of the holder 32 protrudes to the right from the opening 36 of the housing 35.

[0049] Next, the lid 52 is removed from the peripheral wall 49 of the holder 32 and the used canister 31 is pulled out from inside the holder 32. Then, a new canister 31 is inserted into the holder 32 from the insertion port 53, with the discharge port 48 side facing in. The discharge port 48 of the new canister 31 is then connected to the connection port 43 inside the holder 32. After attaching the lid 52 to the peripheral wall 49 of the holder 32, the holder 32 is rotated from the second position to the first position.

[0050] At this time, the cover 52 of the holder 32 slides while pressing against the right side surface 82 of the tip of the claw member 80. As a result, the tip of the claw member 80 is guided into the insertion recess 81 of the cover 52 while retracting into the case 79 against the biasing force of the spring (not shown), and then inserted into the insertion recess 81 by the biasing force of the spring. This locks the holder 32 in the first position.

[0051] Thus, the canister 31 is replaced after rotating the holder 32 to the second position. Therefore, the housing 35 does not get in the way when removing the lid 52 from the peripheral wall 49 of the holder 32 or when pulling out the used canister 31 from inside the holder 32. Consequently, the canister 31 housed in the holder 32 can be easily replaced.

[0052] <Effects of the First Embodiment> According to the first embodiment described in detail above, the following effects are achieved. (1) The fuel cell system 29 comprises a fuel cell 30, a canister 31 that supplies fuel gas to the fuel cell 30, and a holder 32 having a cylindrical peripheral wall 49 that holds the outer circumferential surface of the canister 31. The holder 32 has an insertion port 53 into which the canister 31 is inserted, and a connecting portion 43 to which the canister 31 is detachably connected when the canister 31 is inserted from the insertion port 53, and is mounted on the housing 35 so as to be rotatable between a first position in which the canister 31 is used and a second position in which the canister 31 is replaced, with a pivot axis J1 extending in a direction intersecting the axial direction of the peripheral wall 49 as the pivot center.

[0053] With the above configuration, the canister 31 can be easily replaced by rotating the holder 32 from the first position to the second position and replacing the canister 31 held in the holder 32 with a new one.

[0054] (2) In the fuel cell system 29, the holder 32 has a cover 52 that closes the insertion opening 53. With the above configuration, the canister 31 inserted into the holder 32 from the insertion opening 53 can be prevented from coming out of the insertion opening 53 by the lid 52.

[0055] (3) The fuel cell system 29 is provided with a protrusion 74 for stopping the rotation of the holder 32 in the second position. With the above configuration, the protrusion 74 prevents the holder 32 from rotating beyond the second position more than necessary.

[0056] (4) The fuel cell system 29 is equipped with a locking mechanism 75 that locks the holder 32 in a first position. With the above configuration, when the holder 32 is locked in the first position by the locking mechanism 75, the canister 31 cannot be removed from inside the holder 32, thus deterring theft of the canister 31.

[0057] (5) In the fuel cell system 29, the fuel cell 30 has a coolant supply port 46 through which coolant flows inside the fuel cell 30, and a coolant outlet 47 through which the coolant is discharged. The peripheral wall 49 has an internal flow path 56. The internal flow path 56 has an inlet 59 for introducing coolant discharged from the coolant outlet 47, and an outlet 60 for leading the coolant back to the coolant supply port 46.

[0058] Normally, when fuel such as hydrogen is supplied from the canister 31 to the fuel cell 30, the temperature of the canister 31 decreases, which reduces the amount of fuel supplied from the canister 31 to the fuel cell 30. However, with the above configuration, the coolant heated by cooling the fuel cell 30 flows through the internal passage 56 of the peripheral wall 49 of the holder 32, and the canister 31 inside the holder 32 can be heated by this heated coolant. Therefore, the decrease in the amount of fuel supplied from the canister 31 to the fuel cell 30 can be suppressed.

[0059] (6) The electric assist vehicle 11 is equipped with a fuel cell system 29 and a motor 12 that is powered by the fuel cell 30, and is configured to be able to move by adding the assist driving force from the motor 12 to the human power driving force from the occupant.

[0060] According to the above configuration, effects similar to those described in (1) to (5) above can be obtained. (Second Embodiment) Next, a second embodiment will be described with reference to the drawings.

[0061] The electric assist vehicle 85 of the second embodiment shown in Figure 9 is the same as the electric assist vehicle 11 of the first embodiment, but with the frame 13 changed to a frame 86, the housing 35 changed to a housing 87 as an example of a mounting part, and the mounting configuration of the holder 32 changed. The frame 86 is the same as the frame 13 of the first embodiment, but with the top tube 22 omitted and the down tube 23 changed to a down tube 88 that is curved in a U shape. Aside from these changes, the electric assist vehicle 85 of the second embodiment has a configuration that is generally the same as the electric assist vehicle 11 of the first embodiment.

[0062] In this second embodiment, only the differences from the first embodiment will be described, and explanations that overlap with the first embodiment will be omitted. In this second embodiment, the same reference numerals will be used for the same components as in the first embodiment.

[0063] As shown in Figures 9 and 10, the housing 87 is fixed to the frame 86 in a position extending from the rear end of the down tube 23 to the rear ends of the seat stay 24 and chain stay 25. A receiving recess 89 is formed at the front end of the housing 87, extending along the seat tube 21. The receiving recess 89 is inclined to tilt slightly backward in the vertical direction.

[0064] The receiving recess 89 has a roughly U-shape in cross-section and opens on the upper, lower, and front sides. The peripheral wall 49 of the holder 32 is housed in the receiving recess 89. In this case, the lid 52 of the holder 32 protrudes above the receiving recess 89. The upper surface of the lid 52 is in close proximity to the lower surface of the front part of the saddle 18. The position of the holder 32 when its peripheral wall 49 is housed in the receiving recess 89 is considered to be the first position.

[0065] As shown in Figures 9, 11, and 12, a pair of bearing portions 90 are integrally formed on the lower ends of both the left and right sides of the peripheral wall 49 of the holder 32, with each bearing portion 90 protruding from it. Each bearing portion 90 has an annular bearing body 91 and a projection 92, which is an example of a stopper, that protrudes radially downward from the lower part of the outer circumferential surface of the bearing body 91. The tips of a pair of shaft bolts 94, supported by a pair of mounting brackets 93 fixed inside the housing 87, are rotatably inserted into the bearing body 91 of the pair of bearing portions 90.

[0066] A pair of shaft bolts 94 support the holder 32 so that it can rotate around a pivot axis J2 that extends perpendicular (intersecting) to the axial direction of the peripheral wall 49 of the holder 32 within a pair of bearing portions 90. In this example, the pivot axis J2 is the same as the axis of the shaft bolts 94 and extends in the vehicle width direction. A pair of through holes 95 are formed in the housing 87 at positions corresponding to the pair of bearing portions 90, through which the pair of bearing portions 90 are inserted. The bearing portions 90 are inserted through the through holes 95 so that they can rotate around the pivot axis J2.

[0067] The through hole 95 has a circular first through portion 96 through which the bearing body 91 of the bearing portion 90 is inserted, and a fan-shaped second through portion 97 through which the protruding portion 92 of the bearing portion 90 is inserted. The circumferential front surface of the first through portion 96 in the second through portion 97 is the front contact surface 98. The circumferential rear surface of the first through portion 96 in the second through portion 97 is the rear contact surface 99. The range of rotation of the holder 32 with respect to the pivot axis J2 is limited by the protruding portion 92 contacting the front contact surface 98 or the rear contact surface 99.

[0068] The holder 32 rotates around the pivot axis J2 as the pivot point between a first position (shown in Figure 13) where the projection 92 contacts the front contact surface 98 and a second position (shown in Figure 14) where the projection 92 contacts the rear contact surface 99. In other words, the projection 92 has the function of stopping the holder 32 in the first position by contacting the front contact surface 98 and stopping the holder 32 in the second position by contacting the rear contact surface 99.

[0069] As shown in Figures 2, 9, and 13, the first position is the position in which the peripheral wall 49 of the holder 32 is housed in the housing recess 89 of the housing 87, and the position in which the canister 31 housed in the holder 32 is used. As shown in Figures 2, 9, and 14, the second position is the position in which the lid 52 of the holder 32 is upright so as not to overlap with the saddle 18 in the vertical direction, and the position in which the canister 31 housed in the holder 32 is replaced.

[0070] As shown in Figures 8 to 11 and Figure 13, a bottomed rectangular box-shaped insertion portion 100 with an open left side is formed at the upper end of the left side of the peripheral wall 49 of the holder 32. A locking mechanism 75 is positioned opposite the insertion portion 100 of the holder 32 in the vehicle width direction (left-right direction) when it is in the first position within the housing 87. The keyhole 84 of the locking mechanism 75 is exposed on the front surface of the housing 87. The tip of the claw member 80 of the locking mechanism 75 is inserted into the insertion portion 100 of the holder 32 in the first position through a through hole 101 formed in the housing 87. This locks the holder 32 in the first position.

[0071] <Operation and Effects of the Second Embodiment> To replace a used canister 31, first, insert a key (not shown) into the keyhole 84 and turn it to release the lock on the holder 32 by the locking mechanism 75 in the first position of the holder 32. Next, rotate the holder 32 from the first position to the second position. At this time, the protruding portion 92 comes into contact with the rear contact surface 99, causing the holder 32 to stop in the second position. Then, as shown in Figure 14, the cover 52 of the holder 32 is positioned in front of the saddle 18.

[0072] Next, the lid 52 is removed from the peripheral wall 49 of the holder 32 and the used canister 31 is pulled out from inside the holder 32. Then, a new canister 31 is inserted into the holder 32 from the insertion port 53, with the discharge port 48 side facing in. The discharge port 48 of the new canister 31 is then connected to the connection port 43 inside the holder 32. Next, the lid 52 is attached to the peripheral wall 49 of the holder 32, and then the holder 32 is rotated from the second position to the first position. The holder 32 is then locked in the first position by the locking mechanism 75.

[0073] Thus, the canister 31 is replaced after rotating the holder 32 to the second position. Therefore, the saddle 18 does not get in the way when removing the lid 52 from the peripheral wall 49 of the holder 32 or when pulling out the used canister 31 from inside the holder 32. Consequently, the canister 31 housed in the holder 32 can be easily replaced.

[0074] <Example of changes> Each of the above embodiments can be implemented with the following modifications. Furthermore, each of the above embodiments and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0075] The internal flow path 56 in the peripheral wall 49 of the holder 32 may be omitted. The locking mechanism 75 may be omitted. The protruding portion 74 may be omitted.

[0076] The protruding portion 92 may be omitted. The lid 52 may be omitted. The mounting portion to which the holder 32 is attached may be formed by the down tube 23.

[0077] The peripheral wall 49 may be rectangular or tubular in shape. Canister 31 does not need to contain a hydrogen storage alloy, as long as it is capable of supplying hydrogen gas.

[0078] The electric assist vehicle 11 is not limited to electric assist bicycles, as it is a vehicle configured to be movable by adding the assist driving force from the motor 12 to the human power driving force from the rider. Examples of such vehicles include wheelchairs, kick scooters, and luggage carts.

[0079] <Note> Each of the above embodiments includes the configuration described in the following appendix. [Note 1] A fuel cell system comprising a fuel cell, a canister for supplying fuel gas to the fuel cell, and a holder having a cylindrical peripheral wall for holding the outer circumferential surface of the canister, wherein the holder has an insertion port into which the canister is inserted, and a connecting portion to which the canister is detachably connected when the canister is inserted from the insertion port, and is mounted on a mounting portion so as to be rotatable between a first position in which the canister is used and a second position in which the canister is replaced, with a pivot axis extending in a direction intersecting the axial direction of the peripheral wall as the pivot center.

[0080] [Note 2] The fuel cell system according to [Note 1], characterized in that the holder has a cover that closes the insertion opening. [Note 3] The fuel cell system according to [Note 1] or [Note 2], characterized in that it is provided with a stopper for stopping the rotation of the holder at the second position.

[0081] [Note 4] A fuel cell system according to any one of [Note 1] to [Note 3], characterized in that it is equipped with a locking mechanism for locking the holder in the first position. [Note 5] The fuel cell system according to any one of [Note 1] to [Note 4], characterized in that the fuel cell has a coolant supply port for which coolant flows inside the fuel cell is supplied, and a coolant discharge port for which the coolant is discharged, the peripheral wall has an internal flow path, and the internal flow path has an inlet for introducing the coolant discharged from the coolant discharge port, and an outlet for leading the coolant to the coolant supply port.

[0082] An electric assist vehicle characterized by comprising a fuel cell system described in any one of [Appendix 6], [Appendix 1] to [Appendix 5], and a motor supplied with power from the fuel cell, and configured to be movable by adding an assist driving force from the motor to the human power driving force from the occupant. [Explanation of Symbols]

[0083] 11.85... Electric-assist vehicles 12…motor 29…Fuel cell systems 30…fuel cell 31… Canister 32... Holder 35,87...Housing as an example of a mounting part 43…Connection part 46…Cooling liquid supply port 47…Cooling liquid outlet 49...peripheral wall 52... Lid 53... Insertion opening 56…Internal flow path 59... Inlet 60... Outlet 74... A protruding part as an example of a stopper 75... Locking mechanism 92...Protrusion as an example of a stopper J1, J2... Rotation axis

Claims

1. A fuel cell system comprising a fuel cell, a canister for supplying fuel gas to the fuel cell, and a holder having a cylindrical peripheral wall for holding the outer surface of the canister, The fuel cell system is characterized in that the holder has an insertion port into which the canister is inserted, and a connecting portion to which the canister is detachably connected when the canister is inserted from the insertion port, and is mounted on a mounting portion so as to be rotatable between a first position in which the canister is used and a second position in which the canister is replaced, with the pivot axis extending in a direction intersecting the axial direction of the peripheral wall as the pivot center.

2. The fuel cell system according to claim 1, characterized in that the holder has a cover that closes the insertion opening.

3. The fuel cell system according to claim 1 or 2, further characterized by comprising a stopper for stopping the rotation of the holder at the second position.

4. The fuel cell system according to claim 1 or 2, further characterized by comprising a locking mechanism for locking the holder in the first position.

5. The fuel cell has a coolant supply port through which coolant flows inside the fuel cell is supplied, and a coolant discharge port through which the coolant is discharged. The aforementioned peripheral wall has an internal flow path, The fuel cell system according to claim 1 or 2, characterized in that the internal flow path has an inlet for introducing the coolant discharged from the coolant outlet and an outlet for leading the coolant to the coolant supply port.

6. A fuel cell system according to claim 1 or claim 2, and a motor powered by the fuel cell, An electric assist vehicle characterized by being configured to be movable by adding an assisting driving force from the motor to the human power driving force provided by the occupants.

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