Hot-air balloon

Abstract

To provide a balloon having high energy efficiency.SOLUTION: A balloon 1 comprises: an air sac BA1 including a first envelope 2 in contact with an outside air and a second envelope 3 located inside the first envelope 2, forming an outer space 4 filled with gas between the first envelope 2 and the second envelope 3, and forming an inner space 5 inside the second envelope 3; a power generation device that generates power by natural energy; a heating device that is disposed in the inner space 5 in the second envelope 3 and heats the air in the inner space 5 by the power generated by the power generation device; and a cap that separates the air in the inner space 5 from the outside air.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a balloon.

Background Art

[0002] A balloon that floats using heated air is known. For example, Patent Document 1 discloses a hot air balloon that heats the air inside the airbag using the fire injection of a burner to obtain buoyancy.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the hot air balloon of Patent Document 1, in order to prevent the spread of fire in the airbag and supply oxygen, the gas burner is installed at the lower part of the airbag. Therefore, in the flight state, it is necessary to heat the low-temperature air in the upper air. For this reason, the energy efficiency is low. In addition, in a hot air balloon using a gas burner, when the fuel runs out, it is necessary to land once and fill the fuel. For this reason, the flight period is relatively short, and it is difficult to stay in the air for a long time. As a result, the energy efficiency is low.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a balloon with high energy efficiency.

Means for Solving the Problems

[0006] To achieve the above object, the balloon according to the present invention includes: a first balloon skin in contact with the outside air; and a second balloon skin located inside the first balloon skin, forming an outer air portion filled with gas between the first balloon skin and having an inner air portion formed therein, an airbag including: A power generation device that generates electricity using natural energy, A heating device that is disposed in the inner cavity within the second spherical skin and heats the air within the inner cavity with the electric power generated by the power generation device, A cap that partitions the air in the inner cavity from the outside air, and includes.

[0007] The outer cavity may include the inner cavity.

[0008] For example, it may further include a ring-shaped member, the lower end of the first spherical skin is airtightly fixed to the outer peripheral portion of the ring-shaped member, the lower end of the second spherical skin is airtightly fixed to the inner peripheral portion of the ring-shaped member, and the cap is arranged to close the central hole of the ring-shaped member.

[0009] The power generation device may include a wind power generation device that generates electricity by wind power.

[0010] The power generation device may include a solar power generation device that generates electricity by sunlight.

[0011] It may further have a connecting portion that connects the first spherical skin and the second spherical skin.

[0012] It may further have a pressure adjusting means for adjusting the pressure in the inner cavity.

[0013] The heating device may heat the sucked air and discharge the heated air upward.

[0014] It may further have a propulsion mechanism that gives a propulsive force to the balloon and a communication device or an observation device.

Effect of the Invention

[0015] According to the present invention, the balloon itself is provided with a power generation device, and the generated electric power is supplied to a heating device. Since the power generation device generates electricity using natural energy, it is possible to generate electricity even while staying in the air. Therefore, the balloon can stay in the air for a long time without landing. Further, since the airbag includes an inner space portion and an outer space portion surrounding the inner space portion, the outer space portion functions as a kind of heat insulating member, making it difficult for the gas in the inner space portion to be cooled and facilitating maintaining the temperature of the inner space portion at a high temperature. Therefore, the energy efficiency is high.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0017] Hereinafter, a balloon according to an embodiment of the present invention and its operation will be described with reference to the drawings. (Embodiment 1) A balloon according to Embodiment 1 will be described with reference to the drawings. As shown in FIG. 1, in a flyable state, the balloon 1 according to Embodiment 1 includes a balloon envelope BA1 and a gondola section BA2 suspended from the balloon envelope BA1 by a suspension member 21.

[0018] As a whole, the balloon envelope BA1 has a substantially hemispherical shape at its upper part, a substantially conical shape toward the lower part, and an opening at its lower end. The balloon envelope BA1 includes an outer skin 2, an inner skin 3 disposed inside the outer skin 2, a connecting portion 6 connecting the outer skin 2 and the inner skin 3, a heat insulating cap 7, a ring-shaped ring cap 8 located at the lower ends of the outer skin 2 and the inner skin 3, and an electric heater 10.

[0019] The outer skin 2 is a spherical skin that forms the appearance of the balloon envelope BA1 and partitions the outside air and the inner air layer of the balloon envelope BA1. The inner skin 3 is a spherical skin smaller in size than the outer skin 2 and is included in the outer skin 2. The gas layer inside the balloon envelope BA1 is formed double by the outer skin 2 and the inner skin 3. Specifically, the balloon envelope BA1 has an outer space portion 4 between the outer skin 2 and the inner skin 3 and an inner space portion 5 inside the inner skin 3. The outer space portion 4 is arranged and formed so as to surround the inner space portion 5. The outer space portion 4 functions as a kind of heat insulating material and has a function of suppressing the heat in the inner space portion 5 from being transmitted to the outside air and reducing the temperature inside the inner space portion 5. The outer skin 2 and the inner skin 3 are formed of, for example, glass fibers coated with a fluororesin. Therefore, the heat insulation property of the balloon envelope BA1 is high. In this embodiment, for example, argon gas is enclosed in the outer space portion 4. Therefore, the heat insulation property of the balloon envelope BA1 is further enhanced. Note that the outer skin 2 is an example of the "first spherical skin" of the present invention, and the inner skin 3 is an example of the "second spherical skin" of the present invention.

[0020] The airbag BA1 includes a plurality of connecting portions 6 that connect the outer skin 2 and the inner skin 3. The connecting portion 6 is composed of a breathable strip-shaped cloth or the like, one end of which is fixed to the inner surface of the outer skin 2, and the other end of which is fixed to the outer surface of the inner skin 3. By the connecting portion 6, the relative positional relationship between the outer skin 2 and the inner skin 3 is maintained, and the shapes of the outer skin 2 and the inner skin 3 during inflation are retained, and the region of the outer space portion 4 is maintained. The outer skin 2 and the inner skin 3 have an opening at the lower end portion.

[0021] The ring cap 8 is composed of a ring-shaped strip member (ring-shaped member) and is airtightly attached to the openings at the lower ends of the outer skin 2 and the inner skin 3. Thereby, the shape of the lower portions of the outer skin 2 and the inner skin 3 is retained and the outer space portion 4 is maintained in an airtight state. The ring cap 8 includes a joint jb for injecting or exhausting argon gas from the outside into the outer space portion 4. A hole (opening) is formed in the central portion of the ring cap 8. The lower end portion of the outer skin 2 is airtightly attached along the outer periphery of the ring cap 8. Also, the lower end portion of the inner skin 3 is airtightly attached along the inner periphery of the ring cap 8. The central hole of the ring cap 8 is closed by the heat insulating cap 7.

[0022] The heat insulation cap 7 is formed of a heat-insulating material and is attached to the lower end of the airbag BA1 so as to block the opening of the inner skin 3. The heat insulation cap 7 partitions the internal air in the internal space 5 of the airbag BA1 from the outside air and plays a role in suppressing the heat transfer between the inside and the outside of the airbag BA1. The heat insulation cap 7 is provided with holes ha through which the wirings EL and SL pass. The wiring (power line) EL connects the electric heater 10 disposed in the internal space 5 and the battery 22 disposed in the gondola part BA2. Also, the wiring (signal line) SL connects the control device 30 to the electric heater 10, the battery 22, and the altitude measuring device 60. Also, the signal line SL connects the control device 30 to the altitude measuring device 60 and the monitoring device 90. Further, the heat insulation cap 7 is provided with a joint ja for injecting or exhausting air from the outside into the internal space 5. The joint ja has a function of a pressure valve and exhausts the air in the internal space 5 to the outside air when the pressure Pin in the internal space 5 becomes higher than the outside air pressure Pout by a certain ratio α or more {Pin≧Pout*(1.0 + α)}. Note that α is a positive value smaller than 1, for example, about 0.5 to 0.05. The joint ja is an example of a pressure adjusting means for adjusting the pressure in the internal space 5.

[0023] The electric heater 10 is fixed to the heat insulation cap 7 by a fixing member 11. The fixing member 11 is configured in a frame shape, for example, and maintains the distance between the electric heater 10 and the heat insulation cap 7 so that air can flow between the electric heater 10 and the heat insulation cap 7.

[0024] The electric heater 10 is composed of, for example, a fan heater including an electric ceramic heater, an infrared carbon heater, etc. The electric heater 10 warms the air sucked in from the suction port disposed on its lower surface and discharges the warmed air upward into the internal space 5. The electric heater 10 has a heating capacity capable of maintaining the temperature of the air in the internal space 5 at about 200°C. The electric heater 10 is an example of the "heating device" of the present invention.

[0025] As indicated by the arrow AF of the dashed line, the electric heater 10 sucks in and warms the air at the lower end of the inner cavity 5, and discharges it into the inner cavity 5. The discharged warm air rises within the inner cavity 5, and near the inner skin 3, it is cooled due to the temperature difference with the inner skin 3 of the outer cavity 4, and then descends. The descending air is sucked into the electric heater 10, warmed, and discharged. In this way, the air circulates within the inner cavity 5. Since the airbag BA1 has a double structure with an outer skin 2 and an inner skin 3, a better heat insulation effect can be obtained compared to a single structure. Also, since the outer cavity 4 is filled with argon gas, an additional heat insulation effect can be obtained. Further, compared with the configuration of gas combustion for warming the low-temperature outside air, the electric heater 10 warms the air circulating within the airbag BA1, so it can be warmed with low energy consumption.

[0026] The gondola part BA2 includes a gondola 20. The gondola 20 is suspended by a suspension member 21 at the lower end of the airbag BA1. In the present embodiment, the shape of the gondola 20 has a rectangular parallelepiped box shape. A wind power generation device 50 is attached to the outside of the bottom surface of the gondola 20. Also, the gondola 20 is equipped with a battery 22, an altitude measuring device 60, and a control device 30.

[0027] The wind power generation device 50 is a device that generates electricity by wind power, which is one of the natural energies. The wind power generation device 50 includes a generator that generates electricity by the rotation of a turbine due to wind power, and converts the rotation of the turbine into electric power. It is desirable for the wind power generation device 50 to generate electricity by at least the horizontal wind component. Also, it is desirable for the wind power generation device 50 to be omnidirectional in the horizontal plane and generate electricity by winds from various horizontal directions. The power generation capacity of the wind power generation device 50 is selected according to the size of the airbag BA1 and the planned flight altitude, but in the cruising state, it is desirable to have a power generation capacity that can satisfy the power consumption of the electric heater 10 by wind power. The electric power generated by the generator is stored in the battery 22. Note that a speed increaser may be provided between the generator and the rotating part of the turbine. The wind power generation device 50 may be, for example, the power generation device disclosed in Japanese Patent No. 7002797. The power generation device disclosed in Japanese Patent No. 7002797 can convert winds from various directions into electric power with high efficiency and is effective as the power generation device of the present invention.

[0028] The battery 22 is connected to the wind power generation device 50 by wiring (not shown in the figure) and stores the electric power generated by the wind power generation device 50. The output terminal of the battery 22 is connected to the electric heater 10 via a wiring (power line) EL to supply electric power. Also, the battery 22 supplies operating power to the control device 30 and the altitude measuring device 60 as well.

[0029] The altitude measuring device 60 measures the flight altitude of the balloon 1. In the present embodiment, the altitude measuring device 60 includes a GPS (Global Positioning Sensor). Note that the measurement of the flight altitude is not limited to the measurement method using GPS, and any other type of measurement method may be used.

[0030] The control device 30 is a device that controls the balloon 1. As shown in FIG. 2, it includes an acquisition unit 31 that acquires information necessary for controlling the balloon 1, a control unit 32 that controls the entire control device 30, a communication unit 33 that serves as a communication interface, and a storage unit 34 that stores data necessary for control.

[0031] The acquisition unit 31 acquires the flight altitude measured by the altitude measuring device 60. The control unit 32 executes a process of controlling ON and OFF of the electric heater 10 based on the flight altitude acquired by the acquisition unit 31. In the present embodiment, this control process is referred to as "temperature control process", which will be described in detail later. Since the buoyancy is controlled by the temperature control based on the flight altitude, no ballast is required. The communication unit 33 performs wireless communication with the electric heater 10 and the altitude measuring device 60. Also, the communication unit 33 performs wireless communication with the ground monitoring device 90.

[0032] The storage unit 34 is composed of memories such as RAM (Random Access Memory) and ROM (Read Only Memory), and stores programs and data necessary for control. Specifically, the storage unit 34 stores a control program for executing the temperature control process described later, that is, a temperature control program. Also, the storage unit 34 stores various threshold values.

[0033] The control device 30 is realized by, for example, a personal computer, and as illustrated in FIG. 3, includes a processor 1001 that executes a temperature control program, a memory 1002 that functions as a main storage area, a secondary storage device 1003 that stores the temperature control program, an input / output (I / O) interface 1004 that inputs and outputs signals, and a communication module 1005 that performs communication, which are connected to each other via a bus 1000.

[0034] The processor 1001 includes, for example, a CPU (Central Processing Unit). The processor 1001 reads the temperature control program stored in the secondary storage device 1003 into the memory 1002 and executes it.

[0035] The memory 1002 includes, for example, a main storage device composed of RAM. The memory 1002 functions as a work memory of the processor 1001 and stores the temperature control program read by the processor 1001 from the secondary storage device 1003.

[0036] The secondary storage device 1003 is composed of a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. The secondary storage device 1003 stores a temperature control program executed by the processor 1001, fixed data, etc.

[0037] The I / O interface 1004 is composed of a USB (Universal Serial Bus) port interface, etc. The I / O interface 1004 transmits, for example, a control signal from the processor 1001 to the electric heater 10 and the battery 22, and transmits a measurement signal from the altitude measuring device 60 to the processor 1001.

[0038] The communication module 1005 is composed of a network interface, etc. The communication module 1005 mediates, for example, communication between the processor 1001 and the ground monitoring device 90.

[0039] Referring to FIGS. 2 and 3, the acquisition unit 31 is composed of, for example, the processor 1001 and the I / O interface 1004. The control unit 32 is composed of, for example, the processor 1001. Also, the communication unit 33 is composed of, for example, the communication module 1005. Also, the storage unit 34 is composed of the memory 1002 and the secondary storage device 1003.

[0040] Next, the operation of the balloon 1 having the above configuration will be described. The balloon 1 has the ability to consume the electric power generated by the wind power generation device 50 and stay in the air for a long time without replenishment. This operation will be described.

[0041] When the balloon 1 is on the ground and in a flight-ready state, the outer space portion 4 is filled with argon gas, and the inner space portion 5 is filled with air heated to about 40°C to 80°C, for example. When ascending from the ground, the electric heater 10 is operated. As a result, the temperature of the air in the inner space portion 5 further rises. As the temperature of the air rises, the pressure in the inner space portion 5 increases, and the air in the inner space portion 5 is exhausted to the outside air through the joint ja. Thereby, the buoyancy of the airbag BA1 increases, and the balloon 1 starts to ascend.

[0042] As it ascends, the external air pressure of the balloon 1 gradually decreases. Also, due to the operation of the electric heater 10, the temperature of the inner space portion 5 further rises. When the external air pressure becomes lower than the inside of the inner space portion 5 by a certain ratio or more, the air in the inner space portion 5 is exhausted to the outside air through the joint ja. Thereby, buoyancy is generated in the airbag BA1, and the balloon 1 further ascends.

[0043] At high altitudes, depending on the altitude, the wind blows at a wind speed 2 to 4 times that on the ground. The balloon 1 is carried along by this wind and moves. For this reason, the wind at a wind speed corresponding to the difference between the wind speed and the moving speed of the balloon 1 constantly blows against the wind power generation device 50, and the wind power generation device 50 continues to generate electricity day and night regardless of the difference in weather, and stores the electric power in the battery 22.

[0044] The electric heater 10 consumes the electric power stored in the battery 22 according to the control of the control device 30, and heats or stops heating the air in the inner space portion 5 so as to fly within a preset flight altitude range. Since there is no circulation between the air in the airbag BA1 and the outside air, and it has a two-layer structure of an air layer in the airbag BA1 and a heat-insulating layer filled with argon gas, the temperature of the air in the airbag BA1 is not likely to decrease. Also, the electric heater 10 heats the relatively high-temperature air in the inner space portion 5. For this reason, the balloon 1 can maintain its flight state with high energy efficiency. Also, even during flight, the wind power generation device 50 constantly continues to generate electricity and stores it in the battery 22. The electric heater 10 consumes the stored electric power of the battery 22 for heating. For this reason, the balloon 1 can continue to fly without descending to the ground.

[0045] Next, during the above flight operation of the balloon 1, the "temperature control process" for controlling the temperature of the air in the airbag BA1 will be described. As described above, the "temperature control process" in the present embodiment is a process of controlling the ON and OFF of the electric heater 10 based on the flight altitude. By this temperature control process, the altitude of the balloon 1 is maintained within the target flight altitude range. When the user activates the control device 30, the control unit 32 executes a temperature control program and starts the temperature control process shown in FIG. 4. Also, the user sets the planned altitude range during the cruise flight of the balloon 1 in the control device 30.

[0046] When starting the temperature control process shown in FIG. 4, first, the acquisition unit 31 acquires the flight altitude of the balloon 1 from the altitude measuring device 60 (step S101). The control unit 32 determines whether the flight altitude of the balloon 1 is lower than a first threshold corresponding to the lower limit value of the altitude range set by the user (step S102). If it is determined that the flight altitude of the balloon 1 is lower than the first threshold (step S102: Yes), the flight altitude of the balloon 1 has not reached the target flight altitude range. Therefore, the control unit 32 operates the electric heater 10 to heat the air in the inner space 5 (step S103). As a result, the altitude of the balloon 1 rises.

[0047] On the other hand, when it is determined that the flight altitude of the balloon 1 is equal to or higher than the first threshold (step S102: No), the control unit 32 determines whether the flight altitude of the balloon 1 is equal to or lower than a second threshold (step S104). The second threshold is larger than the first threshold and corresponds to the upper limit of the target altitude range of the balloon 1. When it is determined that the flight altitude of the balloon 1 is equal to or lower than the second threshold (step S104: Yes), the control unit 32 moves the process to step S106. When the altitude of the balloon 1 is equal to or higher than the first threshold and equal to or lower than the second threshold, the balloon 1 is flying at an altitude within the target flight altitude range. Therefore, the control unit 32 does not control the electric heater 10 and moves the process to step S106.

[0048] When it is determined that the flight altitude of balloon 1 is higher than the second threshold (step S104: No), the flight altitude of balloon 1 exceeds the target flight altitude range. Therefore, the control unit 32 stops the electric heater 10 (step S105). The air in the airbag BA1 will no longer be heated. As a result, the altitude of balloon 1 will tend to decrease.

[0049] After step S103, after step S105, and after it is determined as Yes in step S104, the control unit 32 determines whether there is an end command for the temperature control process (step S106). The control unit 32 determines, for example, whether an end command has been sent from the ground monitoring device 90. When it is determined that the end command for the temperature control process has been sent (step S106: Yes), the control unit 32 stops the operation of the electric heater 10 (step S107) and ends the temperature control process. When the temperature of the air in the airbag BA1 decreases, the altitude of balloon 1 decreases.

[0050] When it is determined that the end command for the temperature control process has not been sent (step S106: No), the control unit 32 returns the process to step S101.

[0051] In this way, balloon 1 can continue to fly without replenishment for a long time while consuming the power generated by the wind power generation device 50 within a preset altitude range.

[0052] Next, the preparation work until balloon 1 takes off will be described with reference to FIGS. 5A to 5C.

[0053] In the storage state, the airbag BA1 and the gondola section BA2 are separated. Also, as shown in FIG. 5A, the outer skin 2 and the inner skin 3 of the airbag BA1 are in a deflated state. Also, the heat insulation cap 7, the ring cap 8, and the electric heater 10 are removed from the airbag BA1.

[0054] In this state, a heat-insulating cap 7 with an electric heater 10 fixed by a fixing member 11 is attached to a ring cap 8 that is airtightly connected to the lower ends of the inner skin 3 and the outer skin 2. Then, as illustrated in FIG. 5B, using an air compressor AIC, air at a temperature that generates a slight buoyancy of about 40° C. to 80° C. is injected into the inner cavity 5 through a joint ja to inflate the inner skin 3 to a certain extent. Also, using a gas cylinder GB filled with argon gas, argon gas is injected into the outer cavity 4 through a joint jb to inflate the outer skin 2. Note that a hose AH connected to the air compressor AIC and a hose BH connected to the gas cylinder GB are connected to the joints ja and jb, respectively, to inject air and argon gas.

[0055] When the injection of argon gas into the outer cavity 4 is completed, the hose BH connected to the gas cylinder GB is removed from the joint jb. When air is injected into the inner cavity 5 to a certain level, for example, about 80% of the air is injected, the hose AH connected to the air compressor AIC is removed from the joint ja.

[0056] Subsequently, the electric heater 10 is driven to heat the air in the inner cavity 5. However, since it is desirable to maintain the stored power of the battery 22 until the flight starts, as shown in FIG. 5C, the wiring EL is connected to an external power source Eg, and power is supplied from the external power source Eg to the electric heater 10.

[0057] The gondola section BA2 is suspended from the balloon BA1 via a suspension member 21. Also, the electric heater 10 and the battery 22 are connected via the wiring EL, and the electric heater 10 and the control device 30 are connected via the wiring SL.

[0058] The electric heater 10 heats the air inside the balloon BA1 and discharges the heated air into the inner cavity 5. Then, the air inside the balloon BA1 becomes light air with a low density, generating buoyancy so that the balloon 1 can float. After that, before takeoff, the wiring EL is disconnected from the external power source Eg, and as shown in FIG. 1, the wiring EL is connected to the battery 22.

[0059] In response to an instruction from the monitoring device 90, the control device 30 starts a control operation, the sandbag in the gondola 20 is removed, and the balloon 1 begins to fly. After the flight starts, the electric heater 10 operates using the power stored in the battery 22.

[0060] As described above, the balloon 1 according to the first embodiment includes an electric heater 10 inside the airbag BA1. The electric heater 10 operates using the battery 22 mounted on the balloon 1 as a power source. The battery 22 stores the power generated by the wind power generation device 50 mounted on the balloon 1. Since the electric heater 10 warms the air inside the airbag BA1, the energy consumption is small compared to a configuration that burns low-temperature outside air. Moreover, the balloon 1 can generate its own electricity by the wind power generation device 50. Therefore, unlike a configuration where the fuel runs out, the balloon 1 can continue to fly for a long time without landing.

[0061] In addition, since the balloon 1 has a double structure having an outer skin 2 and an inner skin 3, the heat insulation effect is greater compared to a single structure. Further, since argon gas is enclosed in the outer space portion 4, the heat insulation effect is even greater.

[0062] (Modification example) The above-described first embodiment can be variously modified. For example, in the first embodiment, the balloon 1 is configured to generate its own electricity by wind power generation. In addition to this, it may generate its own electricity by solar power generation. As shown in FIG. 6, a solar power generation device 40 may be provided outside the side surface of the gondola 20. In addition to the power generated by the wind power generation device 50, the power generated by the solar power generation device 40 may be stored in the battery 22. Thereby, more stable power storage can be realized by self-power generation of wind power generation and solar power generation.

[0063] Also, in the above-described first embodiment, the battery 22 and the altitude measuring device 60 are arranged inside the gondola 20. In addition to this, equipment such as a portable antenna and a TV antenna, and a weather sensor may be mounted.

[0064] Further, the electric heater 10 may be provided with a temperature sensor at its suction port. Thereby, when the temperature in the airbag BA1 reaches a predetermined first temperature, the electric heater 10 may stop heating the intake air. Also, when the temperature in the airbag BA1 becomes equal to or lower than a predetermined second temperature, the electric heater 10 may resume heating the intake air.

[0065] In the first embodiment, a fan heater was exemplified as the electric heater 10, but it is not limited to the fan heater. The configuration of the electric heater 10 is arbitrary as long as it can heat the air in the inner space portion 5.

[0066] Also, in the first embodiment, argon gas was injected into the outer space portion 4, but a gas other than argon gas may be used. However, a gas having a specific gravity smaller than that of air is desirable. Also, in order to ensure the heat insulation function of the outer space portion 4, a gas having a lower heat transfer coefficient than the air in the inner space portion 5 is desirable.

[0067] Also, instead of the outer space portion 4, a material having a small specific gravity, for example, foamed urethane, may be used as a heat insulating material to cover all or part of the outer surface of the inner skin 3 for heat insulation.

[0068] Although an example in which the outer space portion 4 encompasses substantially the entire inner space portion 5 has been shown, the outer space portion 4 may be configured to be disposed only above a part of the inner space portion 5. It may be arranged according to the required degree of the heat insulation effect of the outer space portion 4.

[0069] In the first embodiment, with regard to the temperature control process, hysteresis may be given to the first and second threshold values. Also, in the first embodiment, in the temperature control process, the electric heater 10 was controlled to be turned on and off, but the heating amount of the air may be controlled according to the flight altitude Hr measured by the altitude measuring device 60 and the target altitude Ht. For example, instead of steps S102 to S105 in FIG. 4, based on the deviation ΔH between the flight altitude Hr and the target altitude Ht, by PID (Proportional Integral Derivative) control, for example, the power P used for heating the electric heater 10 may be controlled so that P = α·ΔH + β·∫ΔHdt + γ·dΔH / dt. Here, α, β, and γ are arbitrary coefficients. In addition, the control method itself is arbitrary.

[0070] In the first embodiment, the lower ends of the outer skin 2 and the inner skin 3 are fixed to the ring cap 8. However, as long as the outer space 4 and the inner space 5 can be formed, it is not limited to the example of using the ring cap 8. For example, the lower end of the inner skin 3 may be airtightly fixed to the inner surface of the outer skin 2. Similarly, the lower end of the outer skin 2 may be airtightly fixed to the outer surface of the inner skin 3 or the like.

[0071] In the above embodiment, at the start of the ascent of the balloon 1 (on the ground), the temperature of the air in the inner space 5 was set to a relatively low temperature of 40°C to 80°C, but it is not limited to this. For example, depending on the planned altitude of ascent, high-temperature air that generates a large buoyancy, such as 150°C to 300°C, for example, about 200°C, may be filled into the inner space 5 on the ground. In this case, the balloon 1 can be raised and lowered by controlling the temperature of the air in the inner space 5 with the electric heater 10 without exhausting the air from the inner space 5 to the outside air or supplying the outside air to the inner space 5. Also, the device configuration can be simplified.

[0072] (Second Embodiment) In the second embodiment, by adjusting the internal pressure of the inner space 5, it is possible to cope with both the ascent and descent of the balloon 1. Hereinafter, the balloon of the second embodiment having such a feature will be described centering on the differences from the first embodiment with reference to FIGS. 7 and 8.

[0073] As shown in FIG. 7, a pressure sensor 15 is attached to the inner surface of the heat insulation cap 7. The wiring (signal line) SL connects the pressure sensor 15 and the control device 30 through the hole ha.

[0074] In the gondola 20, a gas supply device such as a compressor and an air cylinder is arranged. In the following description, it is assumed that the gas supply device is the air cylinder AiB.

[0075] An air hose AH is attached to the air cylinder AiB. Also, the joint ja is composed of a three-way joint. One end of one of the three directions of the three-way joint is attached to the joint ja. The remaining two ends are each provided with a first solenoid valve B1 and a second solenoid valve B2. The air hose AH connects the end provided with the first solenoid valve B1 and the air cylinder AiB. The joint ja, the air cylinder AiB, and the control device 30 are an example of pressure adjustment means for adjusting the pressure in the internal space 5.

[0076] Also, the storage unit 34 of the control device 30 stores a reference value Pr(H) of the pressure in the internal space 5 required to obtain buoyancy while maintaining the size of the internal space 5 according to the altitude H of the balloon 1.

[0077] Next, during the flight operation of the balloon 1 with such a configuration, the "air pressure control process" for controlling the air pressure in the internal space 5 of the airbag BA1 will be described. The "air pressure control process" in the present embodiment is a process of controlling the opening and closing of the first solenoid valve B1 and the second solenoid valve B2 based on the altitude H of the balloon 1 and the air pressure Pin in the internal space 5. When the first solenoid valve B1 opens, air is injected from the air cylinder AiB into the internal space 5. On the other hand, when the second solenoid valve B2 opens, the air in the internal space 5 is discharged to the outside of the airbag BA1. By the air pressure control process, the shape of the inner skin 3 is maintained to a certain extent. When the balloon 1 starts flying, the control unit 32 executes an air pressure control program and starts the air pressure control process shown in FIG. 8.

[0078] When starting the air pressure control process shown in FIG. 8, first, the acquisition unit 31 acquires the air pressure Pin in the internal space 5 from the air pressure sensor 15 and acquires the flight altitude H of the balloon 1 from the altitude measuring device 60 (step S201). The control unit 32 reads out the reference value Pr(H) corresponding to the acquired altitude H from the storage unit 34. The control unit 32 obtains a first air pressure threshold value corresponding to the lower limit value PrL of the appropriate pressure range at the altitude H in the internal space 5 based on the read reference value Pr(H). The first air pressure threshold value, that is, the lower limit value PrL of the appropriate pressure range, is set, for example, to 0.95 to 0.85 times the reference value Pr(H).

[0079] Subsequently, the control unit 32 determines whether the air pressure Pin in the inner cavity 5 acquired in step S201 is lower than the lower limit value PrL (= the first air pressure threshold value) (step S202). When it is determined that the air pressure in the inner cavity 5 is lower than the first air pressure threshold value (step S202: Yes), the air pressure in the inner cavity 5 has not reached the pressure required to obtain buoyancy while maintaining the size of the inner cavity 5. Therefore, the control unit 32 performs control to open the first solenoid valve B1 (valve opening) and injects air from the air cylinder AiB into the inner cavity 5 (step S203). By injecting air, the air pressure in the inner cavity 5 rises and the shape of the inner cavity 5 is maintained.

[0080] On the other hand, when it is determined that the air pressure in the inner cavity 5 is equal to or higher than the first air pressure threshold value (step S202: No), the control unit 32 obtains a second air pressure threshold value corresponding to the upper limit value PrU of the appropriate pressure range for the altitude H in the inner cavity 5 based on the reference value Pr(H). The second air pressure threshold value, that is, the upper limit value PrU of the appropriate pressure range, is set, for example, to 1.05 to 1.15 times the reference value Pr(H). Subsequently, the control unit 32 determines whether the air pressure Pin in the inner cavity 5 acquired in step S201 is equal to or lower than the upper limit value PrU (= the second air pressure threshold value) (step S204). When it is determined that the air pressure in the inner cavity 5 is equal to or lower than the second threshold value (step S204: Yes), the air pressure in the inner cavity 5 is within the appropriate pressure range for the altitude H. Therefore, the control unit 32 closes the first solenoid valve B1 and the second solenoid valve B2, does not perform air injection and exhaust of the inner cavity 5, and transfers the process to step S207.

[0081] When it is determined that the air pressure in the inner cavity 5 is higher than the second air pressure threshold value (step S204: No), the air pressure in the inner cavity 5 exceeds the appropriate pressure range corresponding to the altitude H. Therefore, the control unit 32 performs control to open the second solenoid valve B2 (step S206). Thereby, the air in the inner cavity 5 is exhausted and the shape of the inner skin 3 is maintained.

[0082] After step S203, after step S205, after step S206, the control unit 32 determines whether there is an end command for the air pressure control process (step S207). The control unit 32 determines, for example, whether an end command has been transmitted from the ground monitoring device 90. When it is determined that the end command for the air pressure control process has been transmitted (step S207: Yes), the control unit 32 performs control to close the first solenoid valve B1 and the second solenoid valve B2 (step S208). The air pressure control process is terminated.

[0083] When an end command is transmitted from the ground monitoring device 90, the above-described temperature control process also ends.

[0084] When it is determined that the end command for the air pressure control process has not been transmitted (step S207: No), the control unit 32 returns the process to step S201.

[0085] In this way, the balloon 1 maintains the air pressure in the inner space 5 within the pressure range necessary to obtain buoyancy while maintaining the size of the inner space 5 according to the altitude H of the balloon 1. Thereby, the balloon 1 can continue flying while changing the altitude H.

[0086] The control device 30 can repeatedly control the ascent and descent of the balloon 1 by executing the temperature control process shown in FIG. 4 and the air pressure control process shown in FIG. 8 in parallel.

[0087] (Modification example) In the above-described embodiment, the pressure inside the inner cavity 5 was controlled so as to substantially match the appropriate pressure Pr(H) at which buoyancy can be obtained. The present invention is not limited to this. Any method can be used as long as the pressure inside the inner cavity 5 can be adjusted to the extent that the balloon 1 can obtain buoyancy. For example, an outside air pressure sensor for measuring the outside air pressure may be provided, and the air pressure inside the inner cavity 5 may be controlled so as to be larger than the outside air pressure by a reference value. The reference value is set to a value that can ensure the size and shape of the inner cavity 5 to the extent that the buoyancy of the balloon 1 can be obtained, for example. Further, for example, a strain gauge may be attached to the inner skin 3, and the air pressure inside the inner cavity 5 may be controlled so that the inner skin 3 extends to the extent that the size and shape of the inner cavity 5 are such that the balloon 1 can obtain buoyancy. Further, a sensor for measuring the size or shape of the inner cavity 5 may be arranged, and the air pressure inside the inner cavity 5 may be controlled so that the size or shape of the inner cavity 5 satisfies the reference conditions.

[0088] (Embodiment 3) In Embodiments 1 and 2, the balloon 1 does not have the ability of self-propulsion. Therefore, the position of the balloon 1 itself cannot be independently controlled. For example, as illustrated in FIG. 9, the balloon 1 may include a propulsion device 101. The propulsion device 101 generates a propulsion force in the horizontal direction of the balloon 1 and enables the balloon 1 to move in the horizontal direction. Note that the movement in the vertical direction is possible by controlling the electric heater 10. The propulsion device 101 illustrated in FIG. 9 includes a propeller 102, a rudder 103, and a drive and steering device 104 that rotates the propeller 102 and steers the rudder 103. The propulsion device 101 is an example of the "propulsion mechanism" of the present invention.

[0089] The control device 30 controls the drive and steering device 104 and controls the rotation direction and rotation speed of the propeller 102. Thereby, the balloon 1 can move forward and backward. The control device 30 controls the drive and steering device 104 and controls the direction of the rudder 103. Thereby, the traveling direction of the balloon 1 can be controlled. With such a configuration, it is possible to keep the balloon 1 staying at a substantially fixed position or move it along an arbitrary path.

[0090] The control device 30 can control the operation of the balloon 1 using a known navigation method such as an inertial navigation method. For example, the control device 30 measures the position of the balloon 1 from the GPS signal and controls the propulsion device 101 to maintain the target position (e.g., latitude, longitude) set in the storage unit 34, or controls the propulsion device 101 to move according to the route stored in the storage unit 34.

[0091] Note that the altitude H may be adjusted by controlling the pressure of the inner space portion 5 while controlling the temperature of the electric heater 10, as described in Embodiments 1 and 2.

[0092] With such a configuration, for example, communication devices (e.g., devices constituting a base station or a relay station) and observation devices are arranged in the gondola 20, and by maintaining a state of floating at a substantially fixed position for a long period of time, functions exceeding those of existing base stations, relay stations, and fixed-point observation devices can be achieved. Also, it becomes possible to relay communication and observe the ground while moving. The observation device is an example of the "observation device" of the present invention.

[0093] In the above description, pressure control is not performed on the outer space portion 4, but pressure control may be performed.

[0094] The present invention can be implemented in various embodiments and modifications without departing from the broad spirit and scope of the present invention. The above-described embodiments are for explaining the present invention and do not limit the scope of the present invention.

Explanation of Reference Numerals

[0095] 1 Balloon, 2 Outer skin, 3 Inner skin, 4 Outer space part, 5 Inner space part, 6 Connecting part, 7 Heat insulation cap, 8 Ring cap, 10 Electric heater, 11 Fixing member, 15 Air pressure sensor, 20 Gondola, 21 Suspension lower member, 22 Battery, 30 Control device, 31 Acquisition unit, 32 Control unit, 33 Communication unit, 34 Memory unit, 40 Solar power generation device, 50 Wind power generation device, 60 Altitude measuring device, 90 Monitoring device, 101 Propulsion device, 102 Propeller, 103 Rudder, 104 Driving and steering device, 1000 Bus, 1001 Processor, 1002 Memory, 1003 Secondary storage device, 1004 Input / output (I / O) interface, 1005 Communication module, BA1 Airbag, BA2 Gondola part, EL Wiring (power line), ha Hole, ja, jb Joint, AIC Air compressor, AiB Air cylinder, AH Air hose, B1 First solenoid valve, B2 Second solenoid valve, Eg External power supply, SL Wiring (signal line).

Claims

1. An airbag comprising: a first spherical skin in contact with the outside air; and a second spherical skin located inside the first spherical skin, forming an outer space filled with gas between the first spherical skin and having an inner space formed therein. A power generation device that generates electricity by natural energy. A heating device disposed in the inner space within the second spherical skin, heating the air within the inner space by the electric power generated by the power generation device. A cap that partitions the air within the inner space from the outside air. A balloon comprising the above.

2. The outer space encompasses the inner space. The balloon according to Claim 1.

3. Further comprising a ring-shaped member, wherein a lower end portion of the first spherical skin is airtightly fixed to an outer peripheral portion of the ring-shaped member, a lower end portion of the second spherical skin is airtightly fixed to an inner peripheral portion of the ring-shaped member, and the cap is disposed so as to close a central hole of the ring-shaped member. The balloon according to Claim 1.

4. The power generation device includes a wind power generation device that generates electricity by wind power. The balloon according to Claim 1.

5. The power generation device includes a solar power generation device that generates electricity by sunlight. The balloon according to Claim 1.

6. Further having a connecting portion that connects the first spherical skin and the second spherical skin. The balloon according to Claim 1.

7. Further having pressure adjusting means for adjusting the pressure within the inner space. The balloon according to Claim 1.

8. The heating device heats the inhaled air and discharges the heated air upward. The balloon according to Claim 1.

9. Further having a propulsion mechanism that imparts a propulsion force to the balloon, and a communication device or an observation device. The balloon according to any one of Claims 1 to 8.

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