Wave power generation device and wave power generation system

Abstract

Provided are a wave power generation device and a wave power generation system capable of miniaturizing the wave power generation device. 【Solution means】The wave power generation device 10 includes a floating body 11, a housing 12, a first member fixed to the housing 12, a second member fixed to the floating body 11, and a power generation device that converts the relative movement between the first member and the second member into electric power. The housing 12 is arranged to be movable relative to the shore such that its height position changes due to buoyancy. The housing 12 includes a floating portion 50 in a state where a portion 51 floats from the water surface W. The value obtained by dividing the buoyancy of the floating portion 50 that increases when the water surface W rises to a predetermined height by the mass of the housing 12 is smaller than the value obtained by dividing the buoyancy of the floating body 11 that increases when the water surface W rises to the predetermined height by the mass of the floating body 11.

Description

Technical Field

[0001] The present invention relates to a wave power generation device and a wave power generation system.

Background Art

[0002] Patent Document 1 describes a wave power generation device having a floating body floating on the sea. The floating body is fixed to an arm fixed to a quay wall. When the sea level rises, the arm fixed to the quay wall moves the floating body upward by the buoyancy of the floating body, and when the sea level drops, the floating body is moved downward by the gravity of the floating body. A conversion mechanism that converts only the movement when descending into mechanical power is fixed to the floating body. The conversion mechanism transmits the mechanical power to a generator via a chain. The generator converts the mechanical power into electric power.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, the position of the sea surface fluctuates not only due to waves but also due to the ebb and flow of the tide. Depending on the sea, the ebb and flow of the tide may cause the position of the sea surface to fluctuate by several meters. In order to follow the ebb and flow of the tide, the wave power generation device described in Patent Document 1 needs to increase the size of the member (arm fixed to the quay wall) that holds the floating body. As a result, the wave power generation device becomes larger.

[0005] An object of the present disclosure is to provide a wave power generation device and a wave power generation system capable of miniaturizing the wave power generation device.

Means for Solving the Problems

[0006] In order to achieve the above object, a wave power generation device according to a first aspect of the present disclosure includes a floating body at least a part of which can float on the water surface, the floating body being configured such that its height position changes in response to a change in the position of the water surface due to waves, a housing that houses the floating body therein, the housing being configured such that water can pass between the inside and the outside of the housing, a first member fixed to the housing, a second member fixed to the floating body, and a power generation unit that converts relative movement between the first member and the second member into electric power. The housing is arranged to be movable relative to the shore or the seabed such that its height position changes due to buoyancy. The housing includes a housing floating body part that is partially floating above the water surface. A value obtained by dividing the buoyancy of the housing floating body part that increases when the water surface rises to a predetermined height by the mass of the housing is smaller than a value obtained by dividing the buoyancy of the floating body that increases when the water surface rises to the predetermined height by the mass of the floating body.

[0007] A wave power generation system according to a second aspect is a wave power generation system including a plurality of wave power generation devices. Each of the plurality of wave power generation devices includes a floating body at least a part of which can float on the water surface, the floating body being configured such that its height position changes in response to a change in the position of the water surface due to waves, a housing that houses the floating body therein, the housing being configured such that water can pass between the inside and the outside of the housing, a first member fixed to the housing, a second member fixed to the floating body, and a power generation unit that converts relative movement between the first member and the second member into electric power. The housing is arranged to be movable relative to the shore or the seabed such that its height position changes due to buoyancy. The housing includes a housing floating body part that is partially floating above the water surface. A value obtained by dividing the buoyancy of the housing floating body part that increases when the water surface rises to a predetermined height by the mass of the housing is smaller than a value obtained by dividing the buoyancy of the floating body that increases when the water surface rises to the predetermined height by the mass of the floating body. The plurality of wave power generation devices include a first wave power generation device and a second wave power generation device arranged adjacent to the first wave power generation device. The housing of the first wave power generation device is connected to the housing of the second wave power generation device.

Advantages of the Invention

[0008] According to the above configuration, the wave power generation device can be miniaturized.

Brief Description of the Drawings

[0009]

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[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the following embodiments, and design changes can be made as appropriate within the scope that satisfies the configuration of the present disclosure. In the following description, the same parts or parts having the same function are commonly used with the same reference numerals among different drawings, and the repeated description thereof is omitted. In addition, the respective configurations described in the embodiments and modifications may be combined or changed as appropriate. In order to make the description easier to understand, in the drawings referred to below, the configurations are shown in a simplified or schematic manner, or some of the constituent members are omitted.

[0011] [First Embodiment] (Overview of Wave Power Generation System 100) FIG. 1 is a block diagram of a wave power generation system 100 according to the first embodiment. The wave power generation system 100 is a system that converts the energy of waves into electric power. The wave power generation system 100 includes a plurality of wave power generation devices 10. A part of the electric power output by the plurality of wave power generation devices 10 is converted by a power conversion device 101 into a voltage corresponding to a device 102 and supplied to the device 102. Also, a part of the electric power output by the plurality of wave power generation devices 10 is converted by the power conversion device 101 into a voltage corresponding to a storage battery 103 and supplied to the storage battery 103. When the wave power generation system 100 is provided on a quay wall, the device 102 is, for example, a pier light, a light in an onshore facility, and an electrical device.

[0012] (Configuration of Wave Power Generation Device 10) FIG. 2 is a plan view of the wave power generation device 10 as viewed from above. FIG. 3 is a schematic diagram for explaining the floating of the floating body 11. FIGS. 4 and 5 are diagrams for explaining the change in the position of the floating body 11 due to the movement of the water surface W. Here, hereinafter, the upward direction will be described as the Z1 direction, the downward direction as the Z2 direction, the direction from the shore to the sea as the Y1 direction, the direction from the sea to the shore as the Y2 direction, the right direction as viewed from the sea as the X1 direction, and the left direction as viewed from the sea as the X2 direction.

[0013] As shown in FIG. 2, the wave power generation device 10 includes a floating body 11 (float), a housing 12, a first gear 13, a second gear 14, a power generation device 15, a shaft 16, a rack gear 17, a flywheel 18, and an internal floating portion 19.

[0014] As shown in Fig. 3, the floating body 11 is a floating body at least part of which can float on the water surface W. The height position of the floating body 11 changes according to the change in the position of the water surface W due to waves. For example, the floating body 11 is formed in a cylindrical shape with a closed bottom. For example, the floating body 11 can be configured by closing the lower end of a resin pipe. Since air is contained in the floating body 11, the specific gravity of the floating body 11 is smaller than the specific gravity of water. Also, as shown in Fig. 2, the floating body 11 includes a plurality of rollers 11a. The plurality of rollers 11a are in contact with the inner surface 12aa of the housing portion 12a of the housing body 12. For example, each of the plurality of rollers 11a is in contact with the inner surfaces 12aa at the four corners of the housing portion 12a respectively. Thereby, as shown in Figs. 3 and 4, the floating body 11 can move in the vertical direction (Z1 direction or Z2 direction) with respect to the housing body 12 in a state where its movement in the horizontal direction is restricted. In the figures other than Fig. 2, the floating body 11 may be schematically illustrated as a rectangular parallelepiped.

[0015] As shown in Fig. 4, the rope 11b connects the top surface 12ac of the housing portion 12a and the floating body 11. The rope 11b prevents the floating body 11 from detaching from the housing body 12 when the water surface W drops too much. Also, if the user pulls up by holding the rope 11b during maintenance or the like, the floating body 11 can be lifted from the water surface.

[0016] As shown in Fig. 2, the housing body 12 includes a housing portion 12a that surrounds the floating body 11 in plan view. The housing portion 12a houses the floating body 11 inside. As shown in Fig. 3, the housing portion 12a includes a hole portion 12ab through which water can pass between the inside and the outside of the housing body 12.

[0017] FIG. 6 is a perspective view showing the configuration of the wave power generation device 10 according to the first embodiment. As shown in FIG. 6, a plurality of holes 12ab are provided on the front surface of the housing portion 12a. The holes 12ab extend in a direction inclined with respect to the Z1 direction and in a direction inclined with respect to the X1 direction (diagonal) when viewed from the front of the housing 12. For example, the holes 12ab have an oval or elliptical shape. Here, when forming a hole for allowing water to pass between the inside and the outside of the housing in a horizontally extending manner, when the water surface is located at a height position where there is no hole, it becomes difficult for water to pass through the hole. Further, when forming the hole to extend in the vertical direction, although there is no influence on the amount of water passing through the hole with respect to the position of the water surface, a portion without a hole (a part of the housing) partially inhibits the entry of water into the housing. On the other hand, according to the first embodiment, since the holes 12ab extend diagonally when viewed from the front of the housing 12, water can be passed through the holes 12ab regardless of the position of the water surface W, and more water can be passed through compared to the case where the holes are formed to extend in the vertical direction.

[0018] Further, as shown in FIG. 6, the housing 12 is arranged to be movable in the vertical direction with respect to the shore S. A plurality of rails 30 are arranged on the shore S (seawall) so as to extend in the vertical direction. The plurality of rails 30 are fixed to the shore S by anchor bolts (not shown) and are also fixed to the shore S via an angle 31.

[0019] FIG. 7 is a diagram for explaining the fixing of the rail 30 to the housing portion 12a. As shown in FIG. 7, the rail 30 is formed in an H shape in plan view. A member 12b that fits into the groove of the rail 30 is fixed to the surface on the shore S side of the housing portion 12a. The member 12b is restricted from moving in the horizontal direction, while it is not fixed to the rail 30 in the vertical direction. The member 12b is fixed to the housing portion 12a via an elastic member 12c. Thereby, the impact of the wave on the housing portion 12a can be alleviated by the elastic member 12c. As a result, it is possible to prevent the impact from being transmitted to the member 12b and the rail 30. The elastic member 12c includes a spring member. The elastic member 12c may be constituted by a rubber material instead of a spring member (a metal member). Also, although not shown, a brake gear may be disposed between the member 12b and the rail 30.

[0020] FIGS. 8 and 9 are diagrams for explaining the relative movement between the rack gear 17 and the first gear 13 and the second gear 14. As shown in FIG. 5, the rack gear 17 is fixed inside the floating body 11. As shown in FIG. 8, the first gear 13 and the second gear 14 are arranged at intervals. The rack gear 17 has a first tooth portion 17a that meshes with the first gear 13 when the rack gear 17 moves in the Z1 direction, and a second tooth portion 17b that meshes with the second gear 14 when the rack gear 17 moves in the Z2 direction. The first gear 13 and the second gear 14 are constituted by known ratchet gears that can rotate only in one direction. Thereby, when the floating body 11 moves upward (in the Z1 direction) due to the movement of the water surface, the rack gear 17 rotates the first gear 13, and when the floating body 11 moves downward (in the Z2 direction) as shown in FIG. 9, the rack gear 17 rotates the second gear 14.

[0021] As shown in FIG. 2, the shaft 16 is fixed to the first gear 13 and the second gear 14. The shaft 16 is connected to the power generation device 15. When the shaft 16 rotates, a dynamo in the power generation device 15 generates an electromotive force. That is, the power generation device 15 generates electricity by the relative movement between the rack gear 17 and the first gear 13 and the second gear 14. The flywheel 18 is fixed to the shaft 16 while passing through the shaft 16. The flywheel 18 has a disk shape and has a function of stabilizing the rotation of the dynamo in the power generation device 15.

[0022] FIGS. 10 and 11 are diagrams for explaining the operation of the housing 12 following the ebb and flow of the tide according to the first embodiment. As shown in FIG. 10, the housing 12 is arranged to be movable relative to the shore S such that its height position changes due to buoyancy. The housing 12 includes a floating portion 50 in which at least a part of the portion 51 floats from the water surface W. The floating portion 50 includes a portion 51 disposed between the shore S and the housing portion 12a, and a main body portion 52 disposed below the floating body 11 and the housing portion 12a. The main body portion 52 constitutes the bottom of the housing 12. Since the portion 51 is disposed between the shore S and the housing portion 12a, the portion 51 does not prevent the waves from entering the housing portion 12a.

[0023] The main body portion 52 has an upper surface 52a that gradually rises from the sea towards the shore. Thereby, along the upper surface 52a, when the waves enter the inside of the housing portion 12a, the water surface W in the housing portion 12a is likely to rise. Thereby, the amount of movement of the floating body 11 can be increased, so that the amount of power generated by the power generation device 15 can be increased.

[0024] Also, the specific gravity of the floating portion 50 is smaller than the specific gravity of water. The floating portion 50 is made of, for example, expanded polystyrene. Thereby, buoyancy can be generated in the housing portion 12a. At least a part of the portion 51 is disposed above the water surface W. Thereby, as shown in FIG. 10, when the position of the water surface W rises from h1 to h2, the volume of the portion 51 disposed below the water surface W increases. Also, although not shown in FIG. 10, the volume of the internal floating portion 19 disposed below the water surface W increases.

[0025] Here, when the water surface W rises to a predetermined height (from h1 to h2), the buoyancy Ff1 of the floating portion 50 and the internal floating portion 19 that increases, and the mass M1 of the housing 12 are defined. When the water surface W rises to the predetermined height, the buoyancy Ff2 of the floating body 11 that increases and the mass M2 of the floating body 11 are defined. In the first embodiment, the value obtained by dividing the buoyancy Ff1 by the mass M1 is smaller than the value obtained by dividing the buoyancy Ff2 by the mass M2. That is, the wave power generation device 10 is configured to have the relationship of the following formula (1). Ff1 / M1 < Ff2 / M2 ··· (1)

[0026] As in the above formula (1), since the acceleration (Ff1 / M1) of the housing 12 is smaller than the acceleration (Ff2 / M2) of the floating body 11, the speed at which the housing 12 follows the movement of the water surface W is lower than the speed at which the floating body 11 follows the movement of the water surface W. Thereby, the housing 12 follows and moves at a low speed even for the movement of the water surface W with a long period due to "tide ebb and flow" (see FIG. 11), while it is difficult to follow the movement of the water surface W with a short period due to "waves". Also, since the floating body 11 has a high speed, it can follow the movement of the water surface W with a short period due to "waves". For this reason, the first gear 13 and the second gear 14 fixed to the housing 12, which is difficult to follow the waves, and the rack gear 17 fixed to the floating body 11, which moves following the waves, can be relatively moved. Thereby, while enabling power generation by the power generation device 15, the housing 12 can be moved following the tide ebb and flow. As a result, since it is not necessary to greatly increase the housing 12 in the vertical direction, the wave power generation device 10 can be miniaturized.

[0027] Further, as shown in FIG. 11, the container 12 includes a top surface 12d having an inclined surface that slopes downward from the shore S toward the sea. Thereby, when the wave rides up on the shore S, the water that has ridden up on the shore S can be quickly drained into the sea through the inclined surface of the top surface 12d of the container 12.

[0028] Further, as shown in FIG. 11, a member 33 that closes the groove of the rail 30 is disposed at the upper end of the rail 30. According to the member 33, it is possible to prevent the container 12 from detaching from the rail 30.

[0029] (Configuration regarding connection of multiple wave power generation devices 10) FIG. 12 is a schematic plan view of a wave power generation system 100 according to the first embodiment. As shown in FIG. 12, the wave power generation system 100 includes a plurality of wave power generation devices 10, two breakwater units 20, two seal members 40, and a plurality of connection members 60. The plurality of wave power generation devices 10 are arranged adjacent to each other along the shore S. And two adjacent containers 12 are connected by a connection member 60.

[0030] FIG. 13 is a diagram showing the configuration of the connection member 60. As shown in FIG. 13, the connection member 60 is constituted by, for example, a spring member. Thereby, the connection member 60 is configured to be elastically deformable. Thereby, the impact on the two containers 12 connected to each other can be absorbed by the connection member 60. Note that the connection member 60 is not limited to a spring member (a metal member), and may be constituted by a rubber member.

[0031] Further, one of the two wave protection units 20 is arranged at a position in the X1 direction with respect to the plurality of wave power generation devices 10, and the other is arranged at a position in the X2 direction with respect to the plurality of wave power generation devices 10. The two wave protection units 20 are respectively connected to the adjacent wave power generation devices 10 by a connecting member 60. Further, the two wave protection units 20 are arranged on a rail 30 fixed to the shore S. Similar to the wave power generation devices 10, the two wave protection units 20 are arranged so as to be movable in the vertical direction while the horizontal movement is restricted by the rail 30. Thereby, the plurality of wave power generation devices 10 and the two wave protection units 20 are integrated and can follow the ebb and flow of the tide. As a result, when the dimension in the direction along the shore S in which the plurality of wave power generation devices 10 and the two wave protection units 20 are integrated is larger than half the length of the wavelength of the wave, both the rising part and the falling part of the wave enter the wave power generation system 100, so the rising part and the falling part cancel each other out. Thereby, the influence of the wave on the wave power generation system 100 is reduced. As a result, it is possible to follow the ebb and flow of the tide while preventing the influence of the wave on the wave power generation system 100.

[0032] (Configuration of the wave protection unit 20) As shown in FIG. 12, the wave protection unit 20 is arranged on each of both sides of the plurality of wave power generation devices 10. Further, each of the two wave protection units 20 includes a wall member 21 that protrudes from the shore S toward the sea at a position adjacent to the housing 12 along the shore S.

[0033] Here, when a force is applied to the housing 12 in the direction along the shore S (lateral direction), a force is applied to the housing 12 so as to be pulled from the shore S. However, in the first embodiment, since the wave trying to enter the housing 12 in the direction along the shore S (lateral direction) can be blocked by the wall member 21, it is possible to prevent the housing 12 from detaching from the shore.

[0034] Further, as shown in FIG. 12, the wall member 21 is formed flush with the housing 12 in the direction along the shore S. Thereby, it is possible to prevent waves from directly entering the housing 12 from the direction along the shore S (lateral direction). Further, since the wave protection unit 20 is arranged on each of both sides of the plurality of wave power generators 10, it is possible to prevent waves from entering the housing 12 from both directions in the direction along the shore S.

[0035] Further, as shown in FIG. 12, the wall member 21 has a shape (wave protection portion) that gradually approaches the shore S as it moves away from the housing 12 in plan view. Thereby, in the direction along the shore S, the traveling direction of the wave traveling toward the wall member 21 can be changed to the direction toward the open sea. The angle θ1 formed between the wall member 21 and the back surface 24 of the housing 12 is 60 degrees. Note that the angle θ1 is not limited to 60 degrees, and may be, for example, an angle of 30 degrees or more and less than 90 degrees.

[0036] Further, as shown in FIG. 6, the wave protection unit 20 includes a top plate 22 arranged above the wall member 21. The top plate 22 has a shape that slopes downward from the shore S toward the open sea. Thereby, when the wave rides up on the shore S, the water that has ridden up on the shore S can be quickly drained into the sea via the top plate 22.

[0037] (Configuration of the seal member) As shown in FIG. 12, the seal member 40 is arranged at a position between the wave protection unit 20 (wall member 21) and the shore S. Further, the seal member 40 is arranged at a position adjacent to the portion of the wave protection unit 20 on the side opposite to the housing 12 side. That is, when viewed from the open sea (viewed in the Y2 direction), it is arranged on both sides of the plurality of wave power generators 10 and the two wave protection units 20. Thereby, it is possible to prevent waves from entering toward the housing 12 side through between the wall member 21 and the shore S.

[0038] [Second Embodiment] Next, with reference to FIGS. 14 to 16, the wave power generation system 200 according to the second embodiment will be described. In the wave power generation system 200 of the second embodiment, the wave protection unit 220 is fixed to the shore. Further, a plurality of holes 223a are provided in the wave protection unit 220. In the following description, when the same reference numerals as those in the first embodiment are used, the same configuration as that in the first embodiment is shown, and the preceding description is referred to unless otherwise specified.

[0039] FIG. 14 is a perspective view showing the configuration of the wave power generation system 200 according to the second embodiment. FIG. 15 is a plan view showing the configuration of the wave power generation system 200 according to the second embodiment. FIG. 16 is a diagram for explaining the configuration of the reinforcing member 224a of the wave protection unit 220 according to the second embodiment. As shown in FIG. 14, the wave power generation system 200 includes two wave protection units 220 disposed on both the left and right sides of a plurality of wave power generation devices 10 when viewed from the offing.

[0040] As shown in FIG. 15, the wave protection unit 220 protrudes seaward from the wave power generation device 10. As shown in FIG. 14, the wave protection unit 220 includes a side surface 221 on the side farther from the wave power generation device 10 and a side surface 222 on the side closer to the wave power generation device 10. A hole 221a is provided in a portion of the side surface 221 closer to the offing than the center (near the tip). A hole 223a is provided in a portion of the side surface 223 closer to the offing than the center (near the tip). Thereby, water passes through the holes 221a and 223a. As a result, since a part of the water of the wave passes through the wave protection unit 220, the impact on the wave protection unit 220 can be reduced as compared with the case where all the water of the wave collides with the wave protection unit 220. And, since the force of the wave is likely to be applied to the portion of the side surface 221 closer to the offing than the center (the tip portion) and the tip portion of the side surface 223, the impact on the portion on the offing side where the force of the wave is likely to be applied can be reduced. As a result, it is possible to prevent the offing side portion of the wave protection unit 220 from being damaged.

[0041] In addition, in FIG. 16, in the wave protection unit 220, a structure in which the illustrations of the side surface 221 and the side surface 223 are omitted is shown. As shown in FIG. 16, the wave protection unit 220 includes a metal frame body 224 that constitutes each side of the wave protection unit 220, a reinforcing member 224a, an anchor arrangement member 225 that fixes the frame body 224 to the shore S, and an anchor bolt 225a. The anchor arrangement member 225 is fixed to the upper portion of the frame body 224 by welding or the like. Further, the anchor arrangement member 225 is fixed to the shore S by the anchor bolt 225a. The reinforcing member 224a extends gradually upward from the shore S toward the offshore. For example, the reinforcing member 224a extends along the inner surface of the side surface 221 and the inner surface of the side surface 223.

[0042] Here, since the lower portion of the wave protection unit 220 is to be arranged in water, it becomes difficult to fix the lower portion to the shore S (for example, perform welding or the like). Therefore, the reinforcing member 224a can reinforce the shore side portion and the lower portion of the wave protection unit 220, so that it is possible to prevent the shore side portion and the lower portion of the wave protection unit 220 from being deformed or damaged. Note that other configurations and effects according to the second embodiment are the same as those of the first embodiment.

[0043] (First Modification Example of the Second Embodiment) Next, with reference to FIG. 17, the configuration of the wave protection unit 320 according to the first modification example of the second embodiment will be described. FIG. 17 is a diagram showing the configuration of the wave protection unit 320 according to the first modification example of the second embodiment. In the above second embodiment, an example in which the hole portions 221a and 223a are provided in the offshore side portions of the side surface 221 and the side surface 223 is shown, but the present disclosure is not limited thereto. For example, as in the wave protection unit 320 according to the first modification example in FIG. 17, the hole portion 323a may be provided only in the side surface 323 on the wave power generation device side. Further, the hole portion 323a may be provided not only in the offshore side portion of the side surface 323 but also in the entire surface of the side surface 323.

[0044] (Second Modification Example of the Second Embodiment) Next, with reference to FIG. 18, the configuration of the wave protection unit 420 according to the second modification of the second embodiment will be described. FIG. 18 is a diagram showing the configuration of the wave protection unit 420 according to the second modification of the second embodiment. In the above-described second embodiment, an example is shown in which a plurality of hole portions 221a and a plurality of hole portions 223a are provided in the offshore portion of the side surface 221 and the offshore portion of the side surface 223. However, the present disclosure is not limited thereto. For example, as in the wave protection unit 420 according to the second modification shown in FIG. 18, a slit 421a that allows water to pass through may be provided on the side surface 421, and a slit 423a that allows water to pass through may be provided on the side surface 423.

[0045] [Third Embodiment] Next, with reference to FIGS. 19 and 20, the wave power generation system 500 according to the third embodiment will be described. In the wave power generation system 500 of the third embodiment, a wave collecting structure is provided in the housing portion 512a. In the following description, when the same reference numerals as those in the first embodiment are used, the same configuration as that in the first embodiment is shown, and the preceding description is referred to unless otherwise specified.

[0046] FIG. 19 is a perspective view showing the configuration of the wave power generation device 510 of the wave power generation system 500 according to the third embodiment. FIG. 20 is a plan view showing the configuration of the wave power generation device 510 of the wave power generation system 500 according to the third embodiment. As shown in FIG. 19, the wave power generation system 500 includes a wave power generation device 510. The wave power generation device 510 includes a housing portion 512a and a floating portion 550. As shown in FIG. 20, the housing portion 512a includes two surfaces 512aa that gradually approach the floating body 11 in the Y2 direction (from the sea to the shore). The two surfaces 512aa are arranged so as to sandwich the floating body 11 from the left and right in plan view. Thereby, the water of the wave that collides with the two surfaces 512aa is collected in the housing portion 512a. Further, the floating portion 550 has an upper surface 552 that gradually rises toward the shore, similar to the floating portion 50 of the first embodiment. The upper surface 552 also collects the wave water in the housing portion 512a. As a result, the movement amount of the floating body 11 increases, so that the power generation amount can be increased. Further, a part of the floating portion 550 is in a state of floating from the water surface W. This floating portion can be substituted for the portion 51 of the floating portion 50 shown in the first embodiment. Note that other configurations and effects according to the third embodiment are the same as those of the first embodiment.

[0047] [Fourth Embodiment] Next, the wave power generation system 600 according to the fourth embodiment will be described with reference to FIG. 21. In the wave power generation system 600 of the fourth embodiment, a wave concentrating structure is provided in the wave protection unit 620. In the following description, when the same reference numerals as those in the first embodiment are used, the same configurations as those in the first embodiment are shown, and the preceding descriptions are referred to unless otherwise specified.

[0048] FIG. 21 is a plan view showing the configuration of the wave power generation system 600 according to the fourth embodiment. As shown in FIG. 21, the wave power generation system 600 includes a wave protection unit 620. The wave protection unit 620 includes a side surface 621 on the side far from the wave power generation device 10 and a side surface 623 on the side close to the wave power generation device 10 in the direction along the shore S. The wave protection unit 620 has a triangular shape in plan view. The side surface 623 has a shape that gradually approaches the shore S as it approaches the wave power generation device 10 (its housing) in plan view. Since the side surface 623 can guide waves to the wave power generation device 10, the amount of movement of the floating body in the wave power generation device 10 due to waves can be increased. As a result, the power generation amount by the wave power generation device 10 can be increased. Note that other configurations and effects according to the fourth embodiment are the same as those of the first embodiment.

[0049] (Modification of the Fourth Embodiment) Next, with reference to FIG. 22, the configuration of the wave power generation system 700 according to a modification (the third modification) of the fourth embodiment will be described. In the fourth embodiment, a wave protection unit 620 having a triangular shape in plan view was provided, but in the third modification, as shown in FIG. 22, a wave protection unit 720 having a semi-circular shape in plan view is provided in the wave power generation system 700. The wave protection unit 720 is arranged such that the curved surface of the wave protection unit 720 is disposed on the offshore side. Thereby, the curved surface on the side close to the wave power generation device 10 of the wave protection unit 720 collects waves with respect to the wave power generation device 10, and the curved surface on the side far from the wave power generation device 10 of the wave protection unit 720 protects against waves with respect to the wave power generation device 10.

[0050] [Modification] The above-described embodiments are merely examples for implementing the present disclosure. Therefore, the present disclosure is not limited to the above-described embodiments, and it is possible to appropriately modify and implement the above-described embodiments without departing from the spirit thereof.

[0051] (1) In the above first to fourth embodiments, an example of arranging the wave protection units on both sides of the wave power generation device has been shown, but the present disclosure is not limited thereto. For example, as in the wave power generation system 800 according to the fourth modification example shown in FIG. 23, when there is a shore S on one side (X2 direction) of the wave power generation device 10, the wave protection unit 20 may be arranged only on the other side (X1 direction) of the wave power generation device 10. Also, as in the wave power generation system 801 according to the fifth modification example shown in FIG. 24, the wave protection unit 220 may be arranged only on the other side (X1 direction) of the wave power generation device 10. Further, as in the wave power generation system 802 according to the sixth modification example shown in FIG. 25, in a place where waves are unlikely to occur in the X1 direction or the X2 direction with respect to the wave power generation device 10, the wave protection unit may not be provided.

[0052] (2) In the above first to fourth embodiments, an example of arranging two wave protection units on both sides of the wave power generation device has been shown, but the present disclosure is not limited thereto. For example, as in the wave power generation system 900 according to the seventh modification example shown in FIG. 26, the wave protection unit 920 may be arranged so as to surround a plurality of wave power generation devices 10. The wave protection unit 920 includes, for example, a surface 921 in which a plurality of slits 921a are formed and a surface 922 in which a plurality of slits 922a are formed. The surface 921 and the surface 922 are arranged to overlap, and water can pass from the open sea side to the side of the plurality of wave power generation devices 10 through the plurality of slits 921a and the plurality of slits 922a. Also, as in the wave power generation system 901 according to the eighth modification example shown in FIG. 27, a wall member 1070 may be arranged so as to surround a plurality of wave power generation devices 10 and the wave protection unit 220. In this case, the wall member 1070 is provided with holes or slits through which water can pass. Further, as in the wave power generation system 902 according to the ninth modification example shown in FIG. 28, a box member 970 surrounding a plurality of wave power generation devices 10 may be provided. The box member 970 can use, for example, a cargo container. The box member 970 is provided with a plurality of holes 971 for allowing water to pass through.

[0053] (3) In the above-described first to fourth embodiments, an example in which the wave power generation devices are arranged side by side in a single row with respect to the shore has been shown, but the present disclosure is not limited thereto. For example, like the wave power generation system 1000 according to the tenth modification shown in FIG. 29, a plurality of wave power generation devices 10 (a plurality of containers) arranged in a line from the shore toward the sea may be connected by a connecting member 60. Thereby, even when waves with different water surface positions enter the wave power generation system 1000 from the sea toward the shore, the influence of the waves can be prevented.

[0054] (4) In the above-described first to fourth embodiments, an example in which the wave protection unit is provided with a wave protection function and a wave collection function has been shown, but the present disclosure is not limited thereto. For example, like the wave power generation system 1100 according to the eleventh modification shown in FIG. 30, the wave protection unit 1120 (a wall member protruding from the shore toward the sea at a position adjacent to the container) may be composed of a fender. As the fender, a material having higher flexibility than metals such as resin, styrofoam, or rubber can be used. Thereby, while preventing the ship from being damaged, the ship can be brought into contact with the wave protection unit 1120 to land the ship on the shore S. In FIG. 30, an example of a fender having a rectangular shape in plan view has been shown, but the present disclosure is not limited thereto. That is, the fender may be configured in a semicircular shape or have a triangular shape in plan view.

[0055] (5) In the above-described first to fourth embodiments, an example in which the side surface of the wave protection unit is arranged vertically has been shown, but the present disclosure is not limited thereto. For example, like the wave protection unit 1220 according to the twelfth modification shown in FIG. 31, it may be configured to have a surface 1222 having a shape gradually moving away from the container (not shown) downward and a surface 1221 having a shape gradually approaching the container downward. The wave protection unit 1220 has, for example, a shape imitating a coral reef. Thereby, while lifting the wave toward the container upward, the traveling direction of the wave can be changed to the direction toward the sea. Thereby, the direction of the force (impact) applied to the wave protection unit 1220 can be dispersed.

[0056] (6) In the above-described first to fourth embodiments, an example in which the floating body is arranged to be vertically movable by rollers that contact the four corners of the container has been shown. However, the present disclosure is not limited to this. For example, like the wave power generation device 1310 according to the 13th modification example shown in FIG. 32, two rollers 1311b may be arranged on each of the four side surfaces of the rectangular floating body 1311 in plan view. Each of the plurality of rollers 1311b contacts the inner surface of the container 1312. Thereby, the floating body 1311 is arranged to be vertically movable inside the container 1312.

[0057] (7) In the above-described first to fourth embodiments, an example in which the wave protection units are arranged on each of both sides of the plurality of wave power generation devices has been shown. However, the present disclosure is not limited to this. For example, like the wave power generation system 1400 according to the 14th modification example shown in FIG. 33, a wave protection unit 1420 may be arranged between the plurality of wave power generation devices 10. Also, like the plurality of wave protection units 1420 shown in FIG. 33, the surface 1421 of the wave protection unit 1420 in the X2 direction may be inclined with respect to the direction from the sea to the shore, and the surface 1422 of the wave protection unit 1420 in the X1 direction may be formed parallel to the direction from the sea to the shore.

[0058] (8) In the above-described first to fourth embodiments, an example of the shape of the wave protection unit has been shown. However, the present disclosure is not limited to this. For example, like the wave power generation system 1500 according to the 15th modification example shown in FIG. 34, the side surface 1521 of the wave protection unit 1520 may extend toward the sea so as to cover a part of the wave power generation device 10 when viewed from the front. Also, like the wave power generation system 1600 according to the 16th modification example shown in FIG. 35, the side surface 1621 of the wave protection unit 1620 covers a part of the wave power generation device 10 when viewed from the front, and the triangular portion of the wave protection unit 1620 in plan view may be arranged on the sea side of the wave power generation device 10.

[0059] (9) In the above-described first to fourth embodiments, an example in which a rack gear is directly provided on the floating body has been shown, but the present disclosure is not limited thereto. For example, like the wave power generation device 1710 according to the 17th modification shown in FIG. 39, the floating body 1711 may be connected to one end of a rope 1711a. A part of the rope 1711a is disposed on a pulley 1711b. Further, a bell 1711c is connected to the other end of the rope 1711a. The floating body 1711 is suspended by the weight of the bell 1711c. Due to the movement of the water surface W, the floating body 1711 moves and the pulley 1711b rotates, so that the rotational movement of the pulley 1711b is transmitted to the power generation device, and power is generated by the power generation device.

[0060] Specifically, the rotational movement of the pulley 1711b is transmitted to the power generation device 2560 by the rotational force transmission mechanism 2500 shown in FIGS. 40 and 41. As shown in FIG. 40, the rotational force of the pulley 1711b is transmitted to the first gear 2551 via the shaft 2523, and as the first gear 2551 rotates, the first ratchet gear 2552, the third gear 2556, the second gear 2555, and the fourth gear 2557 are sequentially rotated, and thus the rotational force is sequentially transmitted to these gears. Here, the rotational force transmitted to the fourth gear 2557 is transmitted to the dynamo of the power generation device 2560 via the shaft 2558 as the fourth gear 2557 rotates. In this case, since the rotational direction of the rotational force transmitted to the dynamo coincides with the power generation rotational direction, the rotor of the dynamo can be driven by the rotational force, and power generation can be performed. Further, the rotational force transmitted to the second gear 2555 is transmitted to the flywheel 2580 via the shaft 2570 as the second gear 2555 rotates. In this case, since the rotational direction of the rotational force transmitted to the flywheel 2580 coincides with the power generation rotational direction, the rotor of the dynamo and the third gear 2556, the second gear 2555, and the fourth gear 2557 can be stably rotated. Although the rotational force transmitted to the second gear 2555 is transmitted to the second ratchet gear 2554 as the second gear 2555 rotates, the second ratchet gear 2554 idles due to the above-described limitation on the rotational direction of the second ratchet gear 2554.

[0061] FIG. 41 is a diagram showing the operation of the rotational force transmission mechanism 2500 when rotating in the direction opposite to the rotational direction shown in FIG. 40 (hereinafter referred to as the "second rotational direction"). As shown in FIG. 41, the rotational force of the pulley 1711b is sequentially transmitted to the second gear 2555, the third gear 2556, and the fourth gear 2557 as the second ratchet gear 2554 rotates, and is sequentially transmitted to these gears. Here, the rotational force transmitted to the fourth gear 2557 is transmitted to the dynamo of the power generation device 2560 as the fourth gear 2557 rotates. In this case, since the rotational direction of the rotational force transmitted to the dynamo coincides with the power generation rotational direction, the rotor of the dynamo can be driven by the rotational force, enabling power generation. Also, the rotational force transmitted to the second gear 2555 is transmitted to the flywheel 2580 as the second gear 2555 rotates. In this case, since the rotational direction of the rotational force transmitted to the flywheel 2580 coincides with the power generation rotational direction, the rotor of the dynamo, the third gear 2556, the second gear 2555, and the fourth gear 2557 can be stably rotated. Although the rotational force transmitted to the first gear 2551 is transmitted to the first ratchet gear 2552 as the first gear 2551 rotates, the first ratchet gear 2552 rotates idly due to the above-described limitation on the rotational direction of the first ratchet gear 2552. With this configuration, power generation can be performed by the power generation device 2560 regardless of the rotational direction.

[0062] Also, the rotational motion of the pulley 1711b may be transmitted to the power generation device 2560a by the rotational force transmission mechanism 2500a shown in FIGS. 42 and 43. As shown in FIG. 42, the rotational force of the pulley 1711b is transmitted to the second ratchet gear 2553a via the shaft 2523a. With the rotation of the second ratchet gear 2553a, the second gear 2554a, the shaft 2556a, the third gear 2555a, the first gear 2552a, the shaft 2570a, and the flywheel 2580a are sequentially rotated. Here, the rotational force transmitted to the flywheel 2580a is transmitted to the dynamo of the power generation device 2560a via the shaft 2562a as the flywheel 2580a rotates. Although the rotational force transmitted to the first gear 2552a is transmitted to the first ratchet gear 2551a as the first gear 2552a rotates, the first ratchet gear 2551a idles due to the above-described restriction on the rotational direction of the first ratchet gear 2551a.

[0063] As shown in FIG. 43, the rotational force of the pulley 1711b sequentially rotates the first gear 2552a, the third gear 2555a, the second gear 2554a, and the flywheel 2580a as the first ratchet gear 2551a rotates. The rotational force transmitted to the flywheel 2580a is transmitted to the dynamo of the power generation device 2560a as the flywheel 2580a rotates. Although the rotational force transmitted to the second gear 2554a is transmitted to the second ratchet gear 2553a as the second gear 2554a rotates, the second ratchet gear 2553a idles due to the above-described restriction on the rotational direction of the second ratchet gear 2553a.

[0064] (10) In the above-described first to fourth embodiments, an example of configuring the container so that the floating body is surrounded by the container has been shown, but the present disclosure is not limited thereto. For example, like the wave power generation device 1810 according to the 17th modification shown in FIG. 36, the floating body 1811 is arranged in a state of being exposed from the container 1812. A rack gear 1817 is fixed to the floating body 1811. A first gear 1813, a second gear 1814, and a flywheel 1818 are fixed to the container 1812. The floating body 1811 is arranged in a state where the rack gear 1817 meshes with the first gear 1813 and the second gear 1814, and the floating body 1811 is relatively movable in the vertical direction with respect to the container 1812.

[0065] (11) In the above-described first to fourth embodiments, an example in which a wave-breaking unit having a wave-breaking function and a wave-collecting function is provided separately from the wave power generation device has been shown, but the present disclosure is not limited thereto. For example, like the housing 1912 of the wave power generation device 1910 according to the 18th modification example shown in FIG. 44, a wall portion 1912a that gradually moves away from the floating body 11 and a wall portion 1912b that covers the offshore side of the floating body 11 may be provided as the housing 1912 is configured to extend from the shore toward the sea. Further, like the housing 2012 of the wave power generation device 2010 according to the 20th modification example shown in FIG. 45, a wall portion 2012a and a wall portion 2012b that gradually move away from the floating body 11 may be provided as the housing 2012 is configured to extend from the shore toward the sea. Further, like the housing 2112 of the wave power generation device 2110 according to the 21st modification example shown in FIG. 46, wall portions 2112a and 2112b that cover the surfaces of the floating body 11 in the left-right direction (X1 direction and X2 direction) and whose spacing gradually widens in the left-right direction as the housing 2112 extends from the shore toward the sea may be provided. Further, like the housing 2212 of the wave power generation device 2210 according to the 22nd modification example shown in FIG. 47, the housing 2212 may be configured to have a spiral shape. The housing 2212 includes a wall portion 2212a that gradually moves away from the floating body 11 and a wall portion 2212b that covers the offshore side of the floating body 11 as the housing 2212 extends from the shore toward the sea. Further, like the wave power generation device 2610 according to the 25th modification example shown in FIG. 48, wall portions 2612a and 2612b that gradually move away from the floating body 11 and cover a part of the weight 2613 may be provided as the device 2610 is configured to extend from the shore toward the sea. By arranging a plurality of wall portions 2612a continuously along the shore S, the weight 2613 is surrounded by the shore S and the plurality of wall portions 2612a in plan view.

[0066] (12) In the above-described first to fourth embodiments, an example in which the configurations of the two wave protection units arranged on both sides of the wave power generation device are formed symmetrically with respect to the wave power generation device (line-symmetric with respect to the center line in the direction along the shore of the wave power generation device) has been shown. However, the present disclosure is not limited to this. For example, like the wave power generation system 2300 according to the 23rd modification example shown in FIG. 37, the wave protection unit 2321 may have a surface that is recessed toward the wave power generation device 10, while the wave protection unit 2322 may be configured to have a surface that protrudes so as to move away from the wave power generation device 10. Like the wave power generation system 2400 according to the 24th modification example shown in FIG. 38, the wave protection unit 2321 may have a surface that is recessed toward the wave power generation device 10 in the shore side portion and protrudes so as to move away from the wave power generation device 10 in the offshore side portion, while the wave protection unit 2322 may be configured to have a surface that is recessed toward the wave power generation device 10 in the offshore side portion and protrudes so as to move away from the wave power generation device 10 in the shore side portion.

[0067] (13) In the above-described first to fourth embodiments, examples of the number of wave power generation devices (from 1 to 6) have been shown. However, the present disclosure is not limited to this. That is, the number of wave power generation devices may be 1 or may be a number of 7 or more (for example, 20).

[0068] (14) In the above-described first to fourth embodiments, an example in which the power conversion device and the storage battery are provided outside the wave power generation system has been shown. However, the present disclosure is not limited to this. For example, at least one of the power conversion device and the storage battery may be provided inside the wave power generation system.

[0069] (15) In the above-described first to fourth embodiments, as shown in FIG. 6, an example in which the hole portion is formed to be inclined in the horizontal direction and inclined in the vertical direction has been shown. However, the present disclosure is not limited to this. For example, the hole portion may be formed parallel to the horizontal direction or may be formed parallel to the vertical direction.

[0070] (16) In the above-described first to fourth embodiments, an example in which the wave power generation device is arranged on a rail fixed to the shore has been shown, but the present disclosure is not limited thereto. For example, the wave power generation device may be arranged on an arm fixed to the shore, or may be arranged on a vertically extending rail fixed to the seabed.

[0071] (17) In the above-described first to fourth embodiments, an example in which a plurality of wave power generation devices are connected by a connecting member having elasticity has been shown, but the present disclosure is not limited thereto. The connecting member may be composed of bolts and nuts having no elasticity. Further, a plurality of wave power generation devices may be connected by welding without using a connecting member. Also, a plurality of wave power generation devices may not be connected to each other.

[0072] (18) In the above-described first to fourth embodiments, an example in which the upper surface of the floating portion is inclined has been shown, but the present disclosure is not limited thereto. The upper surface of the floating portion may be formed parallel to the horizontal plane.

[0073] (19) In the above-described second embodiment, an example in which two reinforcing members are provided per wave protection unit has been shown, but the present disclosure is not limited thereto. One reinforcing member may be provided per wave protection unit, or three or more reinforcing members may be provided.

[0074] (20) In the above-described first to fourth embodiments, an example in which surfaces (wall members) are provided on both the side of the frame of the wave protection unit close to the container and the side far from the container has been shown, but the present disclosure is not limited thereto. For example, a surface (wall member) may be provided only on the side of the frame of the wave protection unit far from the container.

[0075] (21) In the above-described first to fourth embodiments, an example in which the floating portion is composed of styrofoam has been shown, but the present disclosure is not limited thereto. For example, by enclosing air inside the floating portion, the specific gravity of the floating portion may be made smaller than the specific gravity of water.

[0076] In the above-described first to fourth embodiments, an example in which the tip portion on the offshore side of the wave protection unit is flush with the wave power generation device or is arranged on the offshore side of the tip on the offshore side of the wave power generation device is shown. However, the present disclosure is not limited to this. The tip portion on the offshore side of the wave protection unit may be arranged on the onshore side of the tip on the offshore side of the wave power generation device.

[0077] (23) In the above-described first to fourth embodiments, examples of the shape of the floating body are shown. However, the present disclosure is not limited to this. For example, like the floating body 2711 of the wave power generation device 2710 according to the 26th modification example shown in FIGS. 49 and 50, a concave portion 2713 that is recessed toward the inside of the floating body 2711 may be provided. The concave portion 2713 enables the weight 2711c to pass through. The floating body 2711 and the weight 2711c are connected via a rope 2711a. The rope 2711a causes the pulley 2711b to rotate. The power generation device generates power by the rotational movement of the pulley 2711b. Also, like the wave power generation device 2810 according to the 27th modification example shown in FIG. 51, a hole 2813 that penetrates in the vertical direction may be provided inside the floating body 2811. The hole 2813 enables the weight 2811c to pass through. Thereby, since it is not necessary to arrange the weight 2711c or the weight 2811c at a position different from that of the floating body 2711 or the floating body 2811 in plan view, the wave power generation device can be miniaturized.

[0078] Note that the present disclosure can also be described as follows.

[0079] The wave power generation device according to the first configuration includes a floating body that can float at least partially above the water surface, the height position of which changes in response to the change in the position of the water surface due to waves, a housing that houses the floating body therein, the housing being configured such that water can pass between the inside and the outside of the housing, a first member fixed to the housing, a second member fixed to the floating body, and a power generation unit that converts the relative movement between the first member and the second member into electric power. The housing is arranged to be movable relative to the shore or the seabed such that its height position changes due to buoyancy. The housing includes a housing floating part that is partially floating above the water surface. The value obtained by dividing the buoyancy of the housing floating part that increases when the water surface rises to a predetermined height by the mass of the housing is smaller than the value obtained by dividing the buoyancy of the floating body that increases when the water surface rises to the predetermined height by the mass of the floating body (first configuration).

[0080] According to the above first configuration, the value obtained by dividing the buoyancy of the housing floating part that increases when the water surface rises to a predetermined height by the mass of the housing (acceleration of the housing) is smaller than the value obtained by dividing the buoyancy of the floating body that increases when the water surface rises to the predetermined height by the mass of the floating body (acceleration of the floating body). Therefore, the speed at which the housing follows the movement of the water surface is lower than the speed at which the floating body follows the movement of the water surface. As a result, the housing can follow the movement of the water surface with a long period due to the ebb and flow of the tide even at a low speed, while it becomes difficult to follow the movement of the water surface with a short period due to waves. Also, since the floating body has a high speed, it can follow the movement of the water surface with a short period due to waves. For this reason, the first member fixed to the housing that is difficult to follow the waves and the second member fixed to the floating body that moves following the waves can be relatively moved, enabling power generation by the power generation unit while allowing the housing to move following the ebb and flow of the tide. As a result, since it is not necessary to increase the housing in the vertical direction, the wave power generation device can be miniaturized.

[0081] In the first configuration, the container may be arranged to be movable relative to the shore. The container may include a housing portion that surrounds the floating body in plan view. The container floating body portion may be disposed between the shore and the housing portion (second configuration).

[0082] According to the above second configuration, since the container floating body portion is disposed between the shore and the housing portion, the entry of waves into the housing portion is not hindered by the container floating body portion.

[0083] In the first or second configuration, the container may be arranged to be movable relative to the shore. The container may include a housing portion that surrounds the floating body in plan view, and a bottom portion of the container, which is disposed below the floating body. The upper surface of the bottom portion has a first inclined surface that gradually rises from the sea toward the shore (third configuration).

[0084] According to the above third configuration, as waves enter the interior of the housing portion along the first inclined surface, the water surface is likely to rise inside the housing portion. Thereby, the amount of movement of the floating body can be increased, so that the power generation amount by the power generation unit can be increased.

[0085] In the third configuration, the specific gravity of the bottom portion may be smaller than the specific gravity of water (fourth configuration).

[0086] According to the above fourth configuration, since the bottom portion can generate buoyancy for the housing portion, it is possible to prevent the container floating body portion from becoming large-sized.

[0087] In any one of the first to fourth configurations, the container may be arranged to be movable relative to the shore. The wave power generation device may further include a wall member that protrudes from the shore toward the sea at a position adjacent to the container along the shore (fifth configuration).

[0088] Here, when a force is applied to the container in the direction along the shore (lateral direction), a force is applied to the container so as to be pulled from the shore. On the other hand, according to the fifth configuration, waves attempting to enter the container in the direction along the shore (lateral direction) can be blocked by the wall member, so that the container can be prevented from detaching from the shore.

[0089] In the fifth configuration, the wall member may be arranged to be movable with respect to the shore so that its height position changes due to buoyancy (sixth configuration).

[0090] According to the sixth configuration, since the position of the wall member can be changed following the change in the position of the water surface, the wall member can be downsized.

[0091] In the sixth configuration, the wall member may be connected to the container (seventh configuration).

[0092] According to the seventh configuration, the wall member and the container can be integrally made to follow the ebb and flow of the tide. When the wall member and the container are regarded as an integral structure, the horizontal dimension of the structure can be made larger than the horizontal dimension of the container. As a result, when the horizontal dimension of the structure is small compared to the horizontal dimension of the wave (wavelength), the influence of the movement of the water surface by the wave is less likely to occur in the structure. Thereby, while preventing the influence of the wave, the container can follow the ebb and flow of the tide.

[0093] In the sixth or seventh configuration, the wave power generation device may further include a seal member disposed at a position between the wall member and the shore, and disposed at a position adjacent to a portion of the wall member opposite to the container side (eighth configuration).

[0094] According to the eighth configuration, the seal member can prevent waves from entering toward the container side through between the wall member and the shore.

[0095] In any one of the configurations from the first to the eighth, the container may be arranged to be movable relative to the shore. The top surface of the container may have a second inclined surface that slopes downward from the shore toward the sea (ninth configuration).

[0096] According to the above ninth configuration, when a wave rides up on the shore, the water that has ridden up on the shore can be quickly drained into the sea through the second inclined surface of the top surface of the container.

[0097] In any one of the configurations from the first to the ninth, the container may have a hole that allows water to pass between the inside and the outside of the container. The hole may extend in a direction inclined with respect to the vertical direction and in a direction inclined with respect to the horizontal direction when viewed from the front of the container (tenth configuration).

[0098] Here, when the hole that allows water to pass between the inside and the outside of the container is formed to extend horizontally, when the water surface is located at the height position where there is no hole, it becomes difficult for water to pass through the hole. Also, when the hole is formed to extend vertically, although there is no influence on the amount of water passing through the hole with respect to the position of the water surface, the part without the hole (a part of the container) partially inhibits the entry of water into the container. In contrast, according to the above tenth configuration, since the hole extends in a direction inclined with respect to the vertical direction and in a direction inclined with respect to the horizontal direction when viewed from the front of the container, water can be passed through the hole regardless of the position of the water surface, and more water can be passed through compared to the case where it is formed to extend vertically.

[0099] The wave power generation system according to the 11th configuration is a wave power generation system including a plurality of wave power generation devices. Each of the plurality of wave power generation devices includes a floating body at least partially floating on the water surface, the height position of which changes according to the change in the position of the water surface due to waves, a housing for housing the floating body therein, the housing being configured such that water can pass between the inside and the outside of the housing, a first member fixed to the housing, a second member fixed to the floating body, and a power generation unit that converts the relative movement between the first member and the second member into electric power. The housing is movably arranged relative to the shore or the seabed such that its height position changes by buoyancy. The housing includes a housing floating part that is partially floating above the water surface. The value obtained by dividing the buoyancy of the housing floating part that increases when the water surface rises to a predetermined height by the mass of the housing is smaller than the value obtained by dividing the buoyancy of the floating body that increases when the water surface rises to the predetermined height by the mass of the floating body. The plurality of wave power generation devices include a first wave power generation device and a second wave power generation device arranged adjacent to the first wave power generation device. The housing of the first wave power generation device is connected to the housing of the second wave power generation device (11th configuration).

[0100] According to the above 11th configuration, since it is not necessary to increase the housing in the vertical direction, the wave power generation device can be miniaturized. Further, since the housing of the first wave power generation device is connected to the housing of the second wave power generation device, a plurality of housings can be integrally made to follow the ebb and flow of the tide. The influence of the movement of the water surface due to waves is less likely to occur in the wave power generation system. As a result, the housing can follow the ebb and flow of the tide while preventing the influence of waves.

[0101] In the 11th configuration, the housing of the first wave power generation device and the housing of the second wave power generation device may be arranged side by side along the shore (12th configuration).

[0102] According to the above 12th configuration, when waves with different water surface positions enter the wave power generation system in the direction along the shore, the influence of the waves can be prevented.

[0103] In the 11th configuration or the 12th configuration, the wave power generation system may further include a connecting member that connects the housing of the first wave power generation device and the housing of the second wave power generation device. The connecting member may be configured to be elastically deformable (13th configuration).

[0104] According to the 13th configuration described above, the connecting member can absorb the impact on the housing of the first wave power generation device and the housing of the second wave power generation device.

[0105] In any one of the 11th to 13th configurations, the plurality of wave power generation devices may include a third wave power generation device disposed adjacent to the first wave power generation device. The housing of the third wave power generation device may be connected to the housing of the first wave power generation device. The housing of the first wave power generation device and the housing of the third wave power generation device may be arranged side by side from the shore toward the sea (14th configuration).

[0106] According to the 14th configuration described above, when waves with different water surface positions enter the wave power generation system from the sea toward the shore, the influence of the waves can be prevented.

Explanation of Reference Numerals

[0107] 10: Wave power generation device, 11: Floating body, 11a: Roller, 11b: Rope, 12: Container, 12a: Housing part, 12aa: Inner surface, 12ab: Hole part, 12ac: Top surface, 12b: Member, 12c: Elastic member, 12d: Top surface, 13: First gear, 14: Second gear, 15: Power generation device, 16: Shaft, 17: Rack gear, 17a: First tooth part, 17b: Second tooth part, 18: Flywheel, 19: Part, 20: Wave protection unit, 21: Wall member, 22: Top plate, 24: Back surface, 30: Rail, 31: Angle, 33: Member, 40: Seal member, 50: Part, 51: Portion, 52: Main body part, 52a: Upper surface, 60: Connecting member, 100: Wave power generation system, 101: Power conversion device, 102: Equipment, 103: Battery, 200: Wave power generation system, 220: Wave protection unit, 221: Side surface, 221a: Hole part, 222: Side surface, 223: Side surface, 223a: Hole part, 224: Frame body, 224a: Reinforcing member, 225: Anchor arrangement member, 225a: Anchor bolt, 320: Wave protection unit, 323: Side surface, 323a: Hole part, 420: Wave protection unit, 421: Side surface, 421a: Slit, 423: Side surface, 423a: Slit, 500: Wave power generation system, 510: Wave power generation device, 512a: Housing part, 512aa: Surface, 550: Part, 552: Upper surface, 600: Wave power generation system, 620: Wave protection unit, 621: Side surface, 623: Side surface, 700: Wave power generation system, 720: Wave protection unit, 800: Wave power generation system, 801: Wave power generation system, 802: Wave power generation system, 900: Wave power generation system, 901: Wave power generation system, 902: Wave power generation system, 920: Wave protection unit, 921: Surface, 921a: Slit, 922: Surface, 922a: Slit, 970: Box member, 971: Hole part, 1000: Wave power generation system, 1070: Wall member, 1100: Wave power generation system, 1120: Wave protection unit, 1220: Wave protection unit, 1221: Surface, 1222: Surface, 1310: Wave power generation device, 1311: Floating body, 1311b: Roller, 1312: Container, 1400: Wave power generation system, 1420: Wave protection unit, 1421: Surface, 1422: Surface, 1500: Wave power generation system, 1520: Wave protection unit, 1521: Side surface, 1600: Wave power generation system, 1620: Wave protection unit, 1621: Side surface, 1710: Wave power generation device, 1711: Floating body, 1711a: Rope, 1711b: Pulley, 1711c: Bell1810: Wave power generation device, 1811: Floating body, 1812: Container, 1813: First gear, 1814: Second gear, 1817: Rack gear, 1818: Flywheel, 1910: Wave power generation device, 1912: Container, 1912a: Wall part, 1912b: Wall part, 2010: Wave power generation device, 2012: Container, 2012a: Wall part, 2012b: Wall part, 2110: Wave power generation device, 2112: Container, 2112a: Wall part, 2112b: Wall part, 2210: Wave power generation device, 2212: Container, 2212a: Wall part, 2212b: Wall part, 2300: Wave power generation system, 2321: Wave protection unit, 2322: Wave protection unit, 2400: Wave power generation system, 2500: Rotational force transmission mechanism, 2500a: Rotational force transmission mechanism, 2523: Shaft, 2523a: Shaft, 2551: First gear, 2551a: First ratchet gear, 2552: First ratchet gear, 2552a: First gear, 2553a: Second ratchet gear, 2554: Second ratchet gear, 2554a: Second gear, 2555: Second gear, 2555a: Third gear, 2556: Third gear, 2556a: Shaft, 2557: Fourth gear, 2558: Shaft, 2560: Power generation device, 2560a: Power generation device, 2562a: Shaft, 2570: Shaft, 2570a: Shaft, 2580: Flywheel, 2580a: Flywheel, 2600: Wave power generation system, 2610: Wave power generation device, 2612a: Wall part, 2613: Weight, 2710: Wave power generation device, 2711: Floating body, 2711a: Rope, 2711b: Pulley, 2711c: Weight, 2713: Recess, 2810: Wave power generation device, 2811: Floating body, 2811c: Weight, 2813: Hole, Ff1: Buoyancy, Ff2: Buoyancy, M1: Mass, M2: Mass, S: Shore, W: Water surface, θ1: Angle,

Claims

1. A float at least a part of which is capable of floating on the water surface and whose height position changes in response to a change in the water surface position caused by waves; A container that contains the float therein, the container being configured to allow water to pass between an inside of the container and an outside of the container; a first member fixed to the container, a second member fixed to the float, and a power generation unit that converts the relative movement between the first member and the second member into electricity, The container is arranged to be movable relative to a shore or a seabed so that a height position of the container changes due to buoyancy, The container includes a container floating body part that is partially floating above the water surface, A wave power generation device in which the value obtained by dividing the buoyancy of the container floating body part, which increases when the water surface rises to a predetermined height, by the mass of the container is smaller than the value obtained by dividing the buoyancy of the float, which increases when the water surface rises to the predetermined height, by the mass of the float.

2. The container is arranged to be movable relative to the shore; The container includes a housing portion that surrounds the float in a plan view, The wave power generation device according to claim 1 , wherein the container float portion is disposed between a shore and the housing portion.

3. The container is arranged to be movable relative to the shore; The container is A housing portion that surrounds the floating body in a plan view; a bottom of the container, the bottom being disposed below the floating body; The wave power generation device according to claim 1 , wherein an upper surface of the bottom portion has a first inclined surface that gradually becomes higher from the offshore toward the shore.

4. The wave power generation device according to claim 3 , wherein the specific gravity of the bottom portion is smaller than the specific gravity of water.

5. The container is arranged to be movable relative to the shore; The wave power generation device according to claim 1 , further comprising a wall member protruding from the shore toward the ocean at a position adjacent to the enclosure along the shore.

6. The wave power generation device according to claim 5 , wherein the wall member is arranged movably relative to the shore so that a height position of the wall member changes due to buoyancy.

7. The wave power generation device according to claim 6 , wherein the wall member is connected to the housing.

8. The wave power generation device according to claim 6, further comprising a sealing member arranged at a position between the wall member and the shore, the sealing member being arranged at a position adjacent to a portion of the wall member on the opposite side to the housing side.

9. The container is arranged to be movable relative to the shore; The wave power generation device according to claim 1 , wherein the top surface of the container has a second inclined surface that slopes downward from the shore toward the open sea.

10. the container has a hole for passing water between an inside of the container and an outside of the container, The wave power generation device according to claim 1 , wherein the hole extends in a direction inclined with respect to the vertical direction and in a direction inclined with respect to the horizontal direction when viewed from the front of the container.

11. A wave power generation system including a plurality of wave power generation devices, Each of the plurality of wave power generation devices is A float at least a part of which is capable of floating on the water surface and whose height position changes in response to a change in the water surface position caused by waves; A container that contains the float therein, the container being configured to allow water to pass between an inside of the container and an outside of the container; a first member fixed to the container, a second member fixed to the floating body, and a power generation unit that converts relative movement between the first member and the second member into electricity, The container is arranged to be movable relative to a shore or a seabed so that a height position of the container changes due to buoyancy, The container includes a container floating body part that is partially floating above the water surface, The value obtained by dividing the buoyancy of the container float part, which increases when the water surface rises to a predetermined height, by the mass of the container is smaller than the value obtained by dividing the buoyancy of the float, which increases when the water surface rises to the predetermined height, by the mass of the float; The plurality of wave power generation devices include a first wave power generation device and a second wave power generation device arranged adjacent to the first wave power generation device, A wave power generation system, wherein a housing of the first wave power generation device is connected to a housing of the second wave power generation device.

12. The wave power generation system according to claim 11 , wherein the housing of the first wave power generation device and the housing of the second wave power generation device are arranged side by side along a shore.

13. Further provided is a connecting member that connects the housing of the first wave power generation device and the housing of the second wave power generation device, The wave power generation system according to claim 11 , wherein the connecting member is configured to be elastically deformable.

14. The plurality of wave power generation devices includes a third wave power generation device disposed adjacent to the first wave power generation device, The housing of the third wave power generation device is connected to the housing of the first wave power generation device, The wave power generation system according to claim 11 , wherein the housing of the first wave power generation device and the housing of the third wave power generation device are arranged side by side from the shore toward the open sea.

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