Fuel cell drone

Abstract

To suppress the discharge of water from a discharge tank to the outside.SOLUTION: Gas and liquid discharged from a fuel cell stack 24 flows into a discharge pipe 40. An exhaust pipe 42 and a drain pipe 44 branch off from the downstream end of the discharge pipe 40. A drain tank 46 is connected to the downstream end of the drain pipe 44. At least a portion of the drain pipe 44 is formed with a flexible pipe portion 44B.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This specification discloses a drone. This drone is equipped with a fuel cell as a power source.

Background Art

[0002] A fuel cell drone, also called an FC drone, uses a fuel cell as a power source. The fuel cell is provided with an exhaust port. From the exhaust port, so-called off-gas (also called residual gas) and water are discharged. In Patent Document 1, a gas-liquid separator is used to separate the discharged gas-liquid into exhaust gas and water.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a fuel cell stack is mounted as a power source of a drone, in order to prevent the scattered generated water, it is conceivable to provide a drainage tank. Since the discharged gas-liquid is separated into exhaust gas and water, the drainage tank is connected to an exhaust pipe. The outlet of the exhaust pipe is open to the outside. Therefore, due to the sudden movement of the drone, the water stored in the drainage tank may be discharged to the outside from the exhaust pipe.

[0005] Therefore, this specification discloses a fuel cell drone capable of suppressing the external discharge of water in the discharge tank.

Means for Solving the Problems

[0006] The fuel cell drone disclosed in this specification includes a motor, a fuel cell stack, an exhaust pipe, an exhaust duct, a drain pipe, and a drain tank. The motor drives a propeller. The fuel cell stack supplies power to the motor. The exhaust pipe allows the gas-liquid discharged from the fuel cell stack to flow in. The exhaust duct and the drain pipe branch off from the downstream end of the exhaust pipe. The drain tank is connected to the downstream end of the drain pipe. At least a part of the drain pipe is formed with a flexible pipe portion.

[0007] According to the above configuration, when the fuel cell drone makes a sudden movement and the drain tank is swung around by the drone body, the flexible pipe portion bends and kinks occur. At the location where the kink occurs, the drain pipe is crushed. That is, the opening area is reduced. As a result, the external discharge of the water in the drain tank is suppressed.

Advantages of the Invention

[0008] According to the fuel cell drone disclosed in this specification, it is possible to suppress the external discharge of the water in the discharge tank.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0010] Hereinafter, the configuration of the fuel cell drone 10 will be described with reference to the drawings. FIG. 1 illustrates the overall configuration of the fuel cell drone 10 according to this embodiment. The fuel cell drone 10 includes a control box 12, skids 14, and arms 16A - 16D. The fuel cell drone 10 also includes motors 20A - 20D, propellers 22A - 22D, a fuel cell stack 24, a camera 26, and a hydrogen tank 30. The fuel cell drone 10 further includes an exhaust pipe 40, an exhaust duct 42, a drain pipe 44, and a drain tank 46.

[0011] The fuel cell drone 10 is a so-called FC drone powered by a fuel cell stack 24. Electric power is supplied from the fuel cell stack 24 to electrical devices such as the control box 12, the camera 26, and the motors 20A - 20D.

[0012] The control box 12 is a housing in which the control devices of the fuel cell drone 10 are arranged. For example, the control box 12 includes a flight controller, a PDB (Power Distribution Board), and an ESC (Electric Speed Controller). For example, the ESC is provided in the control box 12 for the number of motors 20A - 20D. Also, sensors such as proximity sensors and acceleration sensors are provided in the control box 12.

[0013] For example, the control box 12 is arranged at the center of the fuselage of the fuel cell drone 10. Here, the center of the fuselage refers to the so-called geometric center. The arms 16A - 16D and the skid 14 are attached to the control box 12. From this, skeletal members are arranged in the control box 12 so as to withstand the loads input from the arms 16A - 16D and the skid 14.

[0014] Hydrogen gas is supplied from the hydrogen tank 30 to the fuel cell stack 24 via the pipe 32. More specifically, hydrogen gas is supplied to the fuel electrode of the fuel cell stack 24. In FIGS. 1 and 2, the illustration of supply control devices such as valves and valve controllers is omitted. Also, air containing oxygen is supplied to the air electrode of the fuel cell stack 24. A compressor (not shown) may be provided in front of the air electrode to increase the oxygen concentration.

[0015] The fuel cell stack 24 is placed, for example, above the control box 12. Further, adjacent to the fuel cell stack 24 and above the control box 12, the camera 26 is arranged.

[0016] A plurality of arms 16A - 16D extend horizontally from the control box 12. That is, the arms 16A - 16D extend from the center of the fuselage of the fuel cell drone 10. The arms 16A - 16D extend radially from the control box 12, for example.

[0017] At the ends of the arms 16A - 16D, that is, at the ends opposite to the connection ends with the control box 12, motors 20A - 20D and propellers 22A - 22D are attached. The motors 20A - 20D rotationally drive the propellers 22A - 22D. The rotation speed of the motors 20A - 20D is controlled by the ESC of the control box 12.

[0018] Note that the fuel cell drone 10 illustrated in FIGS. 1 and 2 is of the so - called four - arm type. However, the fuel cell drone 10 according to this embodiment is not limited to this form. For example, the number of arms 16 may be six or eight.

[0019] Skids 14 extend from the side surfaces of the control box 12. The skids 14 are the legs of the fuel cell drone 10. The skids 14 extend one by one from both side surfaces of the control box 12.

[0020] The hydrogen tank 30 supplies hydrogen gas to the fuel cell stack 24. The hydrogen tank 30 is, for example, a cylindrical tank. The longitudinal axis L1 of the hydrogen tank 30 may intersect with the center of gravity of the fuselage of the fuel cell drone 10, for example.

[0021] The hydrogen tank 30 is arranged, for example, below the arms 16A - 16D and the control box 12. For example, a holder 34 is arranged on the bottom surface of the control box 12. The holder 34 is wound around the side surface of the hydrogen tank 30. From this point, the holder 34 also functions as a protective frame for the hydrogen tank 30. For example, a plurality of holders 34 are provided along the longitudinal axis L1.

[0022] For example, the vertical length of the skid 14 is determined to exceed the diameter of the hydrogen tank 30. The vertical length refers to, for example, the length in the vertical direction from the bottom surface of the control box 12. With such a structure, when the fuel cell drone 10 lands normally, the hydrogen tank 30 is separated from the landing surface.

[0023] An exhaust pipe 40 is connected to the fuel cell stack 24. In the fuel cell stack 24, a reverse reaction of water electrolysis occurs to obtain electric power. Therefore, water is generated in the process of obtaining electric power. In addition, so-called off-gas is generated from the fuel cell stack 24. For example, the off-gas contains hydrogen, carbon dioxide, nitrogen, etc. A gas-liquid mixture of the off-gas and the generated water is discharged from the fuel cell stack 24 and flows into the exhaust pipe 40.

[0024] The exhaust pipe 40 is connected to the downstream ends of the fuel electrode and the air electrode of the fuel cell stack 24. For example, the exhaust pipe 40 extends horizontally from the fuel cell stack 24. Or, the exhaust pipe 40 may extend in a downward inclined shape with respect to the horizontal. To prevent blockage of the exhaust pipe 40, the exhaust pipe 40 is made of a material having a predetermined rigidity. For example, the exhaust pipe 40 is composed of a metal pipe or a rigid resin pipe.

[0025] An exhaust pipe 42 and a drain pipe 44 branch off from the downstream end of the exhaust pipe 40. The exhaust pipe 42 extends, for example, vertically upward. The opening 42A of the exhaust pipe 42 is open to the outside. To prevent blockage of the exhaust pipe 42, the exhaust pipe 42 is made of a material having a predetermined rigidity. For example, the exhaust pipe 42 is composed of a metal pipe or a rigid resin pipe.

[0026] The gas-liquid flowing through the exhaust pipe 40 hits the inner wall of the pipe at the branch point. Since the exhaust containing hydrogen is lighter than air (the atmosphere), it rises in the exhaust pipe 42. Further, the exhaust is discharged to the outside through the opening 42A. Also, water droplets accumulate on the inner wall of the pipe at the branch point. These water droplets flow down the drain pipe 44 and are stored in the drain tank 46.

[0027] At least a part of the drain pipe 44 is formed with a flexible pipe portion. For example, the drain pipe 44 includes a rigid pipe portion 44A and a flexible pipe portion 44B. For example, the rigid pipe portion 44A is integrally formed with the discharge pipe 40 and the drain pipe 44. That is, the discharge pipe 40, the drain pipe 44, and the rigid pipe portion 44A are composed of the same rigid material. For example, the rigid pipe portion 44A, the discharge pipe 40, and the drain pipe 44 are composed of a T-shaped pipe. In this case, since the exhaust pipe 42 faces upward, the rigid pipe portion 44A extends vertically downward.

[0028] The flexible pipe portion 44B is connected to the downstream end of the rigid pipe portion 44A. For example, the flexible pipe portion 44B is composed of a soft resin material such as a rubber pipe. The flexible pipe portion 44B may be connected to the rigid pipe portion 44A using a fitting such as a hose clamp.

[0029] A drain tank 46 is connected to the downstream end of the drain pipe 44. More specifically, the drain tank 46 is connected to the downstream end of the flexible pipe portion 44B (the end portion facing the connection end of the rigid pipe portion 44A). The drain tank 46 may be, for example, a plastic tank. For example, a connection port is provided at the upper end of the drain tank 46.

[0030] For example, the drain tank 46 only connects to the flexible pipe portion 44B. That is, it is not in contact with or fixed to other parts of the fuel cell drone 10. Therefore, the relative position between the drain tank 46 and the body of the fuel cell drone 10 changes according to the deformation of the flexible pipe portion 44B.

[0031] FIG. 2 illustrates the state when the fuel cell drone 10 makes a sudden movement. The sudden movement includes sudden acceleration, sudden stop, and sudden turn. In FIG. 2, an example is shown when the fuel cell drone 10 suddenly accelerates in the left direction of the paper. Along with the sudden movement of the fuel cell drone 10, the drain tank 46 is swung around. At this time, the flexible pipe portion 44B of the drain pipe 44 bends. This bending point is also called a kink 45.

[0032] At the kink 45, the tube is crushed. That is, the cross-sectional area of the flow path decreases. In this way, the flow path connecting the drain tank 46 and the exhaust pipe 42 is blocked by the kink 45. Since the flow path connecting the drain tank 46 and the exhaust pipe 42 is blocked during sudden operation, the water stored in the drain tank 46 is suppressed from being released from the exhaust pipe 42.

[0033] In order to promote the generation of the kink 45 as shown in FIG. 2, the flexible pipe portion 44B is not provided with a reinforcing coil or the like. Further, the flexible pipe portion 44B has a length sufficient to generate the kink 45. For example, the flexible pipe portion 44B is set to a length of 10 cm or more and 20 cm or less.

Explanation of reference numerals

[0034] 10 Fuel cell drone, 12 Control box, 14 Skid, 16A - 16D Arms, 20A - 20D Motors, 22A - 22D Propellers, 24 Fuel cell stack, 26 Camera, 30 Hydrogen tank, 40 Discharge pipe, 42 Exhaust pipe, 42A Opening, 44 Drain pipe, 44A Rigid pipe portion, 44B Flexible pipe portion, 45 Kink, 46 Drain tank.

Claims

Claim 1 a motor for driving a propeller; a fuel cell stack for supplying power to the motor; a discharge pipe into which the gas-liquid discharged from the fuel cell stack flows; an exhaust pipe and a drain pipe branched from the downstream end of the discharge pipe; a drain tank connected to the downstream end of the drain pipe; comprising a flexible pipe portion is formed in at least a part of the drain pipe; a fuel cell drone.

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