Wave power generation device

Abstract

To provide a wave power generating device capable of generating power even during periods when small waves are generated. [Solution] The wave power generator 10 comprises a float 50, at least a portion of which can float on the water surface W, that moves up and down in response to changes in the position of the water surface W caused by waves, a rope 40 and a pulley 31 that convert the up and down movement of the float 50 into rotational movement, and a power generator that converts the rotational movement converted by the rope 40 and the pulley 31 into electricity. The natural vibration period of the up and down movement of the float 50 relative to the water surface W is set to be between 1 second and 15 seconds.

Description

[Technical Field]

[0001] The present invention relates to a wave power generation device. [Background technology]

[0002] Patent Document 1 describes a wave power generation device having a float that floats on the sea. The float is fixed to an arm that is fixed to a quay wall. When the sea level rises, the arm moves the float upward due to the buoyancy of the float, and when the sea level falls, the arm moves the float downward due to the gravity of the float. A conversion mechanism that converts only the movement of the float when it descends into mechanical power is fixed to the float. 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] Japanese Patent Application Laid-Open No. 2009-47147 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, relatively small waves have a short period (for example, 15 seconds or less). The float described in Patent Document 1 moves in accordance with the movement of the sea surface, but in the small waves, the float repeatedly moves up and down in a short period, and the movement amount of the float is small, so the movement amount of the chain connected to the float is also small. In this case, during the period when small waves are occurring, the rotation speed of the turbine in the generator cannot reach the rotation speed required for power generation, which causes a problem of extremely small power generation.

[0005] An object of the present disclosure is to provide a wave power generation device that is capable of generating power even during periods when small waves are occurring. [Means for solving the problem]

[0006] To achieve the above object, a wave power generator according to one aspect of the present disclosure includes a float, at least a portion of which is capable of floating on the water surface and which moves up and down in response to changes in the water surface position due to waves, a conversion mechanism that converts the up and down movement of the float into rotational motion, and a power generation unit that converts the rotational motion converted by the conversion mechanism into electric power. The natural oscillation period of the up and down movement of the float relative to the water surface is set to be between 1 second and 15 seconds. [Effects of the Invention]

[0007] According to the above configuration, power can be generated even during periods when small waves are occurring. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a wave power generation system 100 according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the wave power generation system 100 according to the first embodiment. [Figure 3] FIG. 3 is a plan view of the inside of the housing 12 of the wave power generator 10 as seen from above. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of the gear box 23. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of the gear box 23. [Figure 6] FIG. 6 is a side view of the wave power generation device 10. [Figure 7] FIG. 7 is a diagram showing the configuration of the rail member 70. As shown in FIG. [Figure 8] FIG. 8 is a diagram showing the configuration of the floating body 50 and the rail member 70. As shown in FIG. [Figure 9] FIG. 9 is a top view of the floating body 50. As shown in FIG. [Figure 10] FIG. 10 is a diagram for explaining the period of the natural vibration of the floating body 50. As shown in FIG. [Figure 11] FIG. 11 is a diagram showing the configuration of a wave power generator 10a according to a first modification of the first embodiment. [Figure 12]FIG. 12 is a diagram showing the configuration of a wave power generator 10b according to a second modification of the first embodiment. [Figure 13] FIG. 13 is a diagram showing the configuration of a wave power generator 10c according to a third modification of the first embodiment. [Figure 14] FIG. 14 is a diagram showing the configuration of a wave power generator 10d according to a fourth modification of the first embodiment. [Figure 15] FIG. 15 is a diagram showing the configuration of a wave power generator 10e according to a fifth modification of the first embodiment. [Figure 16] FIG. 16 is a diagram showing the configuration of a wave power generator 10f according to a sixth modified example of the first embodiment. [Figure 17] FIG. 17 is a diagram showing the configuration of a wave power generator 10g according to a seventh modification of the first embodiment. [Figure 18] FIG. 18 is a diagram showing the configuration of a wave power generator 10h according to an eighth modification of the first embodiment. [Figure 19] FIG. 19 is a diagram showing the configuration of a wave power generation device 210 according to the second embodiment. [Figure 20] FIG. 20 is a diagram illustrating a state in which the pair of plate members 252b according to the second embodiment is open. [Figure 21] FIG. 21 is a diagram illustrating a state in which the pair of plate members 252b according to the second embodiment is closed. [Figure 22] FIG. 22 is a diagram showing the configuration of a floating body 250a according to a modification (ninth modification) of the second embodiment. [Figure 23] FIG. 23 is a side view showing the configuration of a wave power generator 310 according to the third embodiment. [Figure 24] FIG. 24 is a diagram showing the configuration of a wave power generation device 310a according to a modification (tenth modification) of the third embodiment. [Figure 25] FIG. 25 is a diagram showing the configuration of a wave power generation device 310b according to a modification (eleventh modification) of the third embodiment. [Figure 26] FIG. 26 is a diagram showing the configuration of a wave power generation device 310c according to a modification (twelfth modification) of the third embodiment. [Figure 27] FIG. 27 is a cross-sectional view showing the configuration of a wave power generator 410 according to the fourth embodiment. [Figure 28] FIG. 28 is a cross-sectional view showing the configuration of a wave power generation device 510 according to the fifth embodiment. [Figure 29] FIG. 29 is a diagram showing the configuration of a floating body 550a according to a modification (thirteenth modification) of the fifth embodiment. [Figure 30] FIG. 30 is a diagram showing the configuration of a floating body 550b according to a modification (fourteenth modification) of the fifth embodiment. [Figure 31] FIG. 31 is a cross-sectional view showing the configuration of a wave power generation device 610 according to the sixth embodiment. [Figure 32] FIG. 32 is a diagram showing the configuration of a wave power generation device 610a according to a modification (15th modification) of the sixth embodiment. [Figure 33] FIG. 33 is a diagram showing the configuration of a wave power generation device 610b according to a modification (sixteenth modification) of the sixth embodiment. [Figure 34] FIG. 34 is a diagram showing the configuration of a wave power generation device 610 according to the seventh embodiment. [Figure 35] FIG. 35 is a diagram showing the configuration of a wave power generation device 610 according to the seventh embodiment. [Figure 36] FIG. 36 is a diagram showing the configuration of a floating body 750a according to a modification (seventeenth modification) of the seventh embodiment. [Figure 37] FIG. 37 is a diagram showing the configuration of a floating body 750b according to a modification (18th modification) of the seventh embodiment. [Figure 38] FIG. 38 is a diagram showing the configuration of a floating body 750c according to a modification (19th modification) of the seventh embodiment. [Figure 39] FIG. 39 is a diagram showing the configuration of a floating body 750d according to a modification (twentieth modification) of the seventh embodiment. [Figure 40] FIG. 40 is a diagram showing the configuration of a wave power generation device 810 according to a twenty-first modified example. [Figure 41] FIG. 41 is a diagram showing the configuration of a wave power generation device 910 according to a twenty-second modified example. [Figure 42]FIG. 42 is a diagram showing the configuration of a wave power generation device 910 according to a 22nd modified example. [Figure 43] FIG. 43 is a diagram showing the configuration of a wave power generation device 1010 according to a twenty-third modified example. [Figure 44] FIG. 44 is a diagram showing the configuration of a floating body 1150 according to a twenty-fourth modified example. [Figure 45] FIG. 45 is a diagram showing the configuration of a wave power generation device 1210 according to a twenty-fifth modified example. [Figure 46] FIG. 46 is a diagram showing the configuration of a wave power generation device 1310 according to a 26th modified example. [Figure 47] FIG. 47 is a diagram showing the configuration of a wave power generation device 1410 according to a 27th modified example. [Figure 48] FIG. 48 is a diagram showing the configuration of a wave power generation device 1510 according to a 28th modified example. [Figure 49] FIG. 49 is a diagram showing the configuration of a wave power generation device 1610 according to a 29th modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] 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 appropriate design modifications can be made within the scope of the configuration of the present disclosure. In the following description, the same reference numerals are used in common between different drawings for identical parts or parts having similar functions, and repeated description thereof will be omitted. In addition, the respective configurations described in the embodiments and modified examples may be combined or modified as appropriate. In addition, to make the description easier to understand, the drawings referred to below show simplified or schematic configurations, and some components are omitted.

[0010] [First embodiment] (Overview of Wave Power Generation System 100) FIG. 1 is a block diagram of a wave power generation system 100 according to a first embodiment. FIG. 2 is a plan view of the wave power generation system 100 according to the first embodiment. The wave power generation system 100 is a system that converts wave energy into electric power. The wave power generation system 100 includes a plurality of wave power generation devices 10. A portion of the electric power output by the plurality of wave power generation devices 10 is converted by a power conversion device 101 to a voltage appropriate for a device 102 and supplied to the device 102. A portion of the electric power output by the plurality of wave power generation devices 10 is also converted by the power conversion device 101 to a voltage appropriate for a storage battery 103 and supplied to the storage battery 103. As shown in FIG. 2, the plurality of wave power generation devices 10 are arranged side by side along a quay S. The devices 102 are, for example, electric lights on a pier, and electric lights and electrical equipment in on-shore facilities.

[0011] (Configuration of wave power generation device 10) Figure 3 is a plan view of the interior of the housing 12 of the wave power generator 10, seen from above. As shown in Figure 3, the wave power generator 10 includes a housing 20, a power generator 21, a flywheel 22, a gearbox 23, shafts 24 to 26, a pulley 31, a pulley 32, and a rope 40. The housing 20 is equipped with the power generator 21 (power generation unit), the flywheel 22, the gearbox 23, the shafts 24 to 26, the pulley 31, the pulley 32, and a first portion 41 of the rope 40. The rope 40, the pulley 31, and the pulley 32 function as a "conversion mechanism" that converts the up and down movement of the floating body 50 into rotational movement.

[0012] <Configuration of the power generating device 21 and the flywheel 22> Power generating device 21 includes a dynamo (not shown). When shaft 25 connected to the dynamo rotates, an electromotive force is generated in the dynamo, and power generating device 21 generates electricity. Flywheel 22 is fixed to shaft 25. Flywheel 22 has a disk shape and functions to stabilize the rotation of the dynamo in power generating device 21 by the moment of inertia generated by the rotation of shaft 25.

[0013] <Gearbox 23 configuration> As shown in FIG. 3 , the shaft 24 and the shaft 25 are connected to the gear box 23. FIGS. 4 and 5 are schematic diagrams showing the configuration of the gear box 23. As shown in FIG. 4 , when the pulley 31 rotates, the rotational force of the pulley 31 is transmitted to the ratchet gear 23a via the shaft 24, and as the ratchet gear 23a rotates, the gear 23b, the shaft 23c, the gear 23d, the gear 23e, the shaft 25, and the flywheel 22 rotate sequentially. Here, the rotational force transmitted to the flywheel 22 is transmitted to the dynamo of the power generating device 21 via the shaft 25 as the flywheel 22 rotates. Note that, although the rotational force transmitted to the gear 23e is transmitted to the ratchet gear 23f as the gear 23e rotates, the direction of rotation of the ratchet gear 23f is restricted, and the ratchet gear 23f rotates freely.

[0014] 5, when pulley 31 rotates in the opposite direction to that in FIG. 4, the rotational force of pulley 31 rotates ratchet gear 23f, sequentially rotating gears 23e, 23d, 23b, and flywheel 22. The rotational force transmitted to flywheel 22 is transmitted to the dynamo of power generator 21 as flywheel 22 rotates. Note that the rotational force transmitted to gear 23b is transmitted to ratchet gear 23a as gear 23b rotates, but the rotational direction of ratchet gear 23a is restricted, causing ratchet gear 23a to spin freely. As a result, gearbox 23 rotates shaft 25 in the same direction regardless of the rotational direction of pulley 31 (shaft 24).

[0015] <Configuration of pulleys 31 and 32> As shown in FIG. 3 , pulley 31 rotates around shaft 24 as the axis of rotation in response to the movement of rope 40. Rope 40 has a first portion 41 that is hung on pulley 31 and pulley 32. That is, first portion 41 connects pulley 31 and pulley 32. Pulley 32 rotates around shaft 26 as the axis of rotation in response to the movement of rope 40. Container 20 includes bottom plate 20a. Bottom plate 20a includes holes 20b and 20c. Rope 40 extends toward the outside (downward) of container 20 through holes 20b and 20c. Rope 40 is connected to float 50 and sinker 60 below container 20. That is, pulley 31 and pulley 32 are disposed above float 50. Moreover, the pulley 31 is disposed closer to the quay wall S than the pulley 32.

[0016] <Configuration of beam member 27> Figure 6 is a side view of the wave power generator 10. Figure 7 is a diagram showing the configuration of the rail member 70. Here, in the following description, the upward direction is the Z1 direction, the downward direction is the Z2 direction, the direction from the shore toward the open sea is the Y1 direction, the direction from the open sea toward the shore is the Y2 direction, the right direction as seen from the open sea is the X1 direction, and the left direction as seen from the open sea is the X2 direction.

[0017] As shown in Fig. 6, the wave power generation device 10 includes a beam member 27. The beam member 27 is fixed to the upper surface of a quay wall S. The beam member 27 is fixed to the quay wall S, for example, with anchor bolts. The housing body 20 is fixed to the beam member 27 so as to protrude from the quay wall S toward the sea and so as to hang down from the beam member 27.

[0018] <Configuration of rail member 70> As shown in Fig. 6, the wave power generation device 10 includes a floating body 50 and a plurality of rail members 70. The floating body 50 is configured so that at least a portion of it can float on the water surface W. For example, the floating body 50 is formed in the shape of a box with air sealed inside.

[0019] The plurality of rail members 70 are fixed to the quay wall S by anchor bolts (not shown). As shown in FIG. 7, the rail member 70 is formed in an H-shape in a plan view. A trolley 71 that fits into a groove of the rail member 70 is fixed to the surface of the float 50 facing the quay wall S. The trolley 71 is restricted from moving horizontally, but is not fixed to the rail member 70 in the vertical direction. The trolley 71 is fixed to the float 50. For example, a plurality of trolleys 71 are fixed to the float 50. Of the plurality of trolleys 71, the trolley 71 located at the top is referred to as an upper trolley 71a, and the trolley 71 located below the upper trolley 71a is referred to as a lower trolley 71b. This allows the float 50 to move vertically while being restricted from moving horizontally. The plurality of trolleys 71 are, for example, treated with anti-rust plating (e.g., zinc plating) or anti-rust painting.

[0020] <Configuration of Weight 60> As shown in Fig. 6, the wave power generator 10 includes a sinker 60. The sinker 60 applies a load to the rope 40, thereby pulling the floating body 50 via the pulleys 31 to 34. This makes it possible to prevent the rope 40 from becoming loose.

[0021] As shown in FIG. 6 , the weight 60 is disposed between the float 50 and the container 20 (pulleys 31 and 32) in the vertical direction. This prevents the weight 60 from sinking in the water. The weight 60 is disposed on the rail member 70 on which the float 50 is disposed so as to be movable up and down. The weight 60 is fixed to a trolley 71 disposed on the rail member 70. This allows the weight 60 to move up and down relative to the rail member 70, while restricting movement of the trolley 71 in the horizontal direction, similar to the float 50 shown in FIG. 7 . The rail member 70 restricts movement of the float 50 and the weight 60 in directions other than the vertical direction (horizontal direction). Furthermore, since the float 50 and the weight 60 are disposed on the same rail member 70, the number of rail members 70 can be reduced compared to when the float 50 and the weight 60 are disposed on separate rail members 70.

[0022] As shown in FIG. 6 , the weight 60 has an upper surface 62 and a lower surface 63. The upper surface 62 has an inclined surface that is inclined with respect to the horizontal plane. For example, the upper surface 62 has a mountain-like shape with an apex at the center. The lower surface 63 also has a mountain-like shape with an apex at the center. As a result, the weight 60 has a shape that tapers upward and downward in a side view. This reduces air resistance when the weight 60 moves up and down. As a result, the resistance to the rotation of the pulley 31 is reduced, and the amount of power generated by the power generation device 21 can be increased.

[0023] <Configuration of pulley 33, pulley 34, and container 29> As shown in FIG. 6 , the wave power generator 10 includes a pulley 33 and a pulley 34 disposed below the float 50, and a box-shaped container 29 that houses the pulleys 33 and 34. The pulley 33 is disposed below the pulley 31 and is disposed closer to the quay wall S than the pulley 34. A fourth portion 44 of the rope 40 is hung between the pulley 33 and the pulley 34. The pulleys 33 and 34 are fixed to the container 29, which is fixed to the quay wall S. The container 29 also includes an upper surface 29a that slopes downward as it moves away from the rail member 70. When waves travel along the upper surface 29a, the water surface W near the float 50 tends to rise, thereby increasing the amount of movement of the float 50. This increases the amount of power generated by the power generator 21.

[0024] <Composition of Rope 40> As shown in FIG. 6 , the rope 40 includes a second portion 42, a third portion 43, a fourth portion 44, and a fifth portion 45. The second portion 42 extends downward from the housing 20 (hole 20b) and is connected to the fourth portion 44. The third portion 43 extends downward from the housing 20 (hole 20c). The third portion 43 also includes an end portion 47 fixed to a hook 61 disposed on an upper surface 62 of the sinker 60. The fourth portion 44 is a portion of the rope 40 that is hooked on the pulleys 33 and 34, and a portion of the fourth portion 44 is disposed below the pulleys 33 and 34. The fifth portion 45 extends upward from the pulley 34 (toward the float 50). The fifth portion 45 includes a hook 54 (end portion) disposed on the float 50. As a result, rope 40 extends downward from floating body 50, and is arranged across (via) pulley 34, pulley 33, pulley 31, and pulley 32, and connected to sinker 60 (arranged in an S-shape). As a result, when floating body 50 rises, rope 40 moves, and sinker 60 rises. When floating body 50 descends, rope 40 moves, and sinker 60 descends. Then, as rope 40 moves, pulley 31 rotates, and the energy of the rotational motion is converted into electricity (power generation) by power generation device 21.

[0025] In this way, the movement of the rope 40 can transmit the motion of the floating body 50 to the power generation device 21. Because the rope 40 is string-like, no housing is required to house the rope 40. This makes it possible to prevent the wave power generation device 10 from becoming larger even if the distance between the water surface W on which the floating body 50 is placed and the power generation device 21 is large. For example, even if the distance between the top surface of the quay S and the water surface W is large, it is possible to prevent the wave power generation device 10 from becoming larger. Furthermore, the distance between the water surface W and the power generation device 21 varies depending on the installation location of the wave power generation device 10, but by changing the length of the rope 40 according to the distance between the water surface W and the power generation device 21, the wave power generation device 10 can be installed in a variety of installation locations.

[0026] Here, the speed at which the water surface W rises due to waves is slower than the speed at which the water surface W falls after the waves have passed. Therefore, when a float is suspended from above by a rope, if the water surface rises more rapidly than the speed at which the pulley rotates, slack will occur in the rope. If the float descends during the period when slack occurs, it becomes difficult to convert the up and down movement of the float into rotational movement of the pulley. In contrast, in the first embodiment, when the float 50 rises, the rope 40 is pulled upward, so that even if the water surface W rises sharply, the rope 40 does not slacken and the pulley 31 rotates. As a result, the amount of power generated by the power generation device 21 can be increased.

[0027] <Configuration of Elastic Member 80> As shown in Figure 6, the wave power generator 10 includes an elastic member 80 that connects the sinker 60 and the floating body 50. Even if the position of the floating body 50 changes suddenly, the elastic member 80 allows the position of the sinker 60 to change in accordance with the movement of the floating body 50. The elastic member 80 is formed, for example, by a spring. However, the elastic member 80 is not limited to this and may be formed by rubber. As a result, it is possible to prevent slack from occurring in the rope 40 that connects the floating body 50 and the sinker 60 via the pulleys 31, 32, 33, and 34.

[0028] <Configuration of box member 28> As shown in Fig. 6, the wave power generator 10 includes a box member 28 that houses a portion of the rail member 70, including the upper end thereof, and has an open bottom. The housing 20 that houses the power generator 21, pulleys 31, and pulleys 32 is disposed above the box member 28. The box member 28 is fixed to the housing 20. The housing 20 and the box member 28 are formed continuously, and all of the box member 28 except for its bottom is sealed. In other words, even if water attempts to seep in from the bottom side of the box member 28, the water will not seep in because there is no escape route for the air inside the box member 28 and the housing 20.

[0029] When relatively large waves occur and the water level W becomes higher than the bottom surface of the box member 28, the box member 28 and the container 20 have no escape route for the air inside the box member 28 and the container 20, so water does not enter. As a result, the water level inside the box member 28 becomes lower than the water level W. As a result, even if the float 50 and the sinker 60 move toward the upper end of the rail member 70, the float 50 and the sinker 60 can be stopped from rising inside the box member 28. The float 50 stops rising near the water level inside the box member 28. This prevents the float 50 and the sinker 60 from colliding with the pulleys 31 and 32.

[0030] <Configuration of Floating Body 50> FIG. 8 is a diagram showing the configuration of the float 50 and the rail member 70. FIG. 9 is a top view of the float 50. As shown in FIG. 8, the float 50 includes a float section 51 and an added mass section 52. The float section 51 has a specific gravity smaller than that of water, and a portion of the float section 51 is positioned (floats) above the water line WL. In the first embodiment, the float section 51 is formed in a box shape, and air is sealed inside. This allows the float section 51 to float on the water surface W.

[0031] As waves travel from offshore toward the quay S (wave power generation device 10), the height position of the water surface W increases. As the water surface W rises, the height position of the floating body 50 increases due to buoyancy. After that, the height position of the water surface W decreases, and as the water surface W descends, the height position of the floating body 50 decreases. As a result, the floating body 50 moves up and down due to the waves. Generally, the amplitude of the waves increases as the period increases, and decreases as the period decreases.

[0032] The additional mass 52 is disposed below the water line WL of the float 51 and is fixed to the lower end of the float 51. This allows the additional mass 52 to move up and down integrally with the float 51. The entire additional mass 52 is submerged below the water surface W.

[0033] FIG. 10 is a diagram illustrating the natural vibration period of the float 50. The mass of the additional mass 52 is greater than the mass of the float portion 51, and the natural vibration period Tn1 of the up and down movement of the float 50 relative to the water surface W is set to a value of 1 second or more and 15 seconds or less. For example, the period Tn1 is set to 5 seconds. As will be described later, the mass of the additional mass 52 includes the mass of the water disposed within the additional mass 52. As shown in FIG. 10, for relatively large waves with a wave period exceeding 15 seconds, the value obtained by dividing the amount of movement of the up and down movement of the float 50 by the amplitude of the wave is approximately 1. In other words, for relatively large waves with a wave period exceeding 15 seconds, the float 50 moves in accordance with the movement.

[0034] As shown in Fig. 10, for relatively small waves with a wave period of 1 second or more and 15 seconds or less, the value obtained by dividing the amount of up and down movement of the float 50 by the amplitude of the wave is greater than approximately 1. The natural vibration period Tn1 at which the value obtained by dividing the amount of up and down movement of the float 50 by the amplitude of the wave reaches its peak value is a value of 1 second or more and 15 seconds or less.

[0035] According to this, during the period when relatively small waves (waves with a period of 1 second or more and 15 seconds or less) are generated, the floating body 50 resonates with the waves, resulting in a movement amount greater than the movement amount of the water surface W. As a result, even during the period when relatively small waves are generated, the movement amount of the floating body 50 can be increased, thereby generating a large rotational motion in the dynamo of the power generation device 21. This allows power to be generated even during the period when small waves are generated. Furthermore, during the period when relatively large waves (waves with a period of more than 15 seconds) are generated, even if the floating body 50 does not resonate, the floating body 50 moves in accordance with the large waves, resulting in a sufficiently large movement amount of the floating body 50. As a result, during both the period when relatively small waves are generated and the period when relatively large waves are generated, a large rotational motion can be generated in the power generation device 21, thereby increasing the amount of power generation. Furthermore, with fine waves (waves with a period of less than 1 second), even if the floating body 50 resonates with the wave motion, it is not possible to ensure a movement amount of the floating body 50 sufficient to contribute to power generation. In contrast, in the above configuration, the period Tn1 is set to 1 second or more, so the motion of the floating body can be resonated with small waves (waves that are not too fine) that contribute to power generation, and as a result, the amount of power generation can be further increased.

[0036] Since the mass of the additional mass portion 52 is greater than the mass of the float portion 51, the period Tn1 can be set to 1 second or more even if the float portion 51 is lightweight.

[0037] As shown in Fig. 8, the floating body 50 is fixed to an upper trolley 71a and a lower trolley 71b via members 72. The members 72 extend in the vertical direction and are fixed to the upper trolley 71a and the lower trolley 71b. This allows the upper trolley 71a, the lower trolley 71b, the members 72, and the floating body 50 to move vertically together.

[0038] The distance L1 between the upper trolley 71a and the lower trolley 71b is greater than the vertical length L2 of the float 50. Here, when the float is arranged to be movable up and down via the upper trolley and the lower trolley relative to rails fixed to the quay wall, waves pushing up the float will push up the part of the float opposite the rails (offshore side). As a result, a force (moment) is applied to the float in a direction that rotates the float around the upper trolley and the lower trolley, and if the distance between the upper trolley and the lower trolley is small, the frictional force between the upper trolley and the lower trolley and the rail increases. As a result, it may be difficult for the upper trolley and the lower trolley to move up and down relative to the rail. In contrast to this, according to the first embodiment, the distance L1 between the upper trolley 71a and the lower trolley 71b is greater than the vertical length L2 of the floating body 50, so it is possible to reduce the moment acting on the floating body 50 around the upper trolley 71a and the lower trolley 71b. As a result, it is possible to reduce the frictional force between the upper trolley 71a and the lower trolley 71b and the rail member 70, so that the floating body 50 can be moved smoothly relative to the rail member 70, and the amount of power generation can be increased.

[0039] As shown in Figure 8, the distance L1 between the upper trolley 71a and the lower trolley 71b is greater than the length L3 of the floating body 50 that protrudes offshore from the upper trolley 71a, and is also greater than the length L3 of the floating body 50 that protrudes offshore from the lower trolley 71b. This reduces the force (moment) that rotates the floating body 50 around the upper trolley 71a and the lower trolley 71b. As a result, the floating body 50 can be moved smoothly relative to the rail member 70, and the amount of power generation can be increased.

[0040] 8, the floating body 50 is disposed at a position below the upper end 71aa of the upper trolley 71a and above the lower end 71ba of the lower trolley 71b. This allows the floating body 50 to be disposed close to both the upper trolley 71a and the lower trolley 71b, thereby enabling the wave power generator 10 to be made smaller.

[0041] The float 50 includes a hook 53 connected to an elastic member 80 for transmitting the up and down movement of the float 50 to the pulley 31, and a hook 54 connected to a rope 40 for transmitting the up and down movement of the float 50 to the pulley 31. The hooks 53 and 54 are positioned closer to the side surface 52b, including the end portion on the rail side, than to the offshore end portion 55 of the float 50. This makes it possible to reduce the force (moment) in the direction of rotation of the float 50 around the upper trolley 71a and the lower trolley 71b, even if an upward pulling force is generated on the float 50 by the rope 40 and the elastic member 80.

[0042] The vertical length L2b of the added mass portion 52 is greater than the vertical length L2a of the float portion 51. As a result, the vertical dimension of the added mass portion 52 is large, and therefore the mass of the added mass portion 52 can be made greater than the mass of the float portion 51 without using (or with a small amount of) other heavy materials. As a result, even if the float portion 51 is lightweight, the period Tn1 can easily be made greater than one second.

[0043] The added mass 52 is configured as a container in which water is placed. The added mass 52 includes a lower surface 52a and a side surface 52b on the rail side. The lower surface 52a has an inclined surface that gradually rises from the member 72 side toward the offshore side (the side in the Y1 direction). This allows waves approaching from the offshore side to push up the inclined surface, thereby increasing the amount of movement of the floating body 50.

[0044] The side surface 52b is provided with holes 52c that allow water to pass through into the added mass 52. For example, the holes 52c are formed as slits extending horizontally. The holes 52c are provided near the lower end and the upper end of the added mass 52. As a result, when the float 50 is placed on water, water enters the added mass 52 through the holes 52c, increasing the mass of the added mass 52. Therefore, the provision of the holes 52c eliminates the need to previously fill the added mass 52 with weights or water. Furthermore, because the water in the added mass 52 can be configured as part of the mass of the added mass 52, there is no need to add a separate weight, and the material used to configure the added mass 52 can be reduced.

[0045] 9, the float 50 has a shape in which the width (length in the direction along the quay wall S) gradually decreases toward the offshore in a plan view. As a result, even if waves travel in a direction along the quay wall S, the waves can be diverted toward the offshore side, preventing a large load from being applied to the float 50 and preventing the float 50 from detaching from the rail member 70.

[0046] [Modification of the first embodiment] Next, a wave power generator according to a modification of the first embodiment will be described with reference to FIGS.

[0047] (First Modification) Fig. 11 is a diagram showing the configuration of a wave power generator 10a according to a first modified example of the first embodiment. As shown in Fig. 11, the wave power generator 10a includes a float 50a. The float 50a includes an added mass 152a. The added mass 152a has a lower surface formed in an arc shape when viewed in the direction along the quay wall S (X direction).

[0048] (Second Modification) Figure 12 is a diagram showing the configuration of a wave power generator 10b according to a second modification of the first embodiment. As shown in Figure 12, the wave power generator 10b includes a float 50b. The float 50b includes an added mass 152b. The added mass 152b has an arc-shaped lower surface when viewed in the direction along the quay wall S (X direction). This lower surface is inclined so as to gradually rise toward the sea (Y1 direction).

[0049] (Third Modification) Figure 13 is a diagram showing the configuration of a wave power generator 10c according to a third modification of the first embodiment. As shown in Figure 13, the wave power generator 10c includes a float 50c. The float 50c includes an added mass 152c. The added mass 152c has a shape that tapers downward. The lower tip of the added mass 152c has an arc shape.

[0050] (Fourth Modification) Fig. 14 is a diagram showing the configuration of a wave power generator 10d according to a fourth modified example of the first embodiment. As shown in Fig. 14, the wave power generator 10d includes a float 50d. The float 50d includes an added mass 152d. The added mass 152d has a shape that tapers downward.

[0051] (Fifth Modification) Fig. 15 is a diagram showing the configuration of a wave power generator 10e according to a fifth modified example of the first embodiment. As shown in Fig. 15, the wave power generator 10e includes a float 50e. The float 50e includes an added mass 152e. The added mass 152e includes a lower surface having an S-shaped portion when viewed in the direction along the quay wall S (X direction). This lower surface is inclined so as to gradually rise toward the sea (Y1 direction).

[0052] (Sixth Modification) Fig. 16 is a diagram showing the configuration of a wave power generator 10f according to a sixth modified example of the first embodiment. As shown in Fig. 16, the wave power generator 10f includes a float 50f. The float 50f includes an added mass 152f. The added mass 152f has an arc shape that is concave upward when viewed in the direction along the quay wall S (X direction).

[0053] (Seventh Modification) Figure 17 is a diagram showing the configuration of a wave power generator 10g according to a seventh modified example of the first embodiment. As shown in Figure 17, the wave power generator 10g includes a float 50g. The float 50g includes an additional mass 152g. The additional mass 152g has a triangular shape when viewed in the direction along the quay wall S (X direction). The additional mass 152g has a triangular prism shape with a cavity inside. The additional mass 152g has a plurality of holes 152ga through which water passes.

[0054] (Eighth Modification) Figure 18 is a diagram showing the configuration of a wave power generator 10h according to an eighth modification of the first embodiment. As shown in Figure 18, the wave power generator 10h includes a floating body 50h. The floating body 50h includes a float section 151h. An upper surface 151ha of the float section 151h has an inclined surface that gradually descends from the member 72 toward the sea. This allows water to flow offshore via the inclined surface even when waves run up on the float section 151h (or on the quay S).

[0055] [Second embodiment] Next, the configuration of a wave power generator 210 according to the second embodiment will be described with reference to Figures 19 to 21. Figure 19 is a side view showing the configuration of the wave power generator 210 according to the second embodiment. As shown in Figure 19, the wave power generator 210 includes a float 250. The float 250 includes an added mass 252. The added mass 252 includes a hinge 252a fixed to the member 72, and a pair of plate members 252b rotatably connected to the hinge 252a. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

[0056] FIG. 20 is a diagram illustrating a state in which the pair of plate members 252b according to the second embodiment are open. FIG. 21 is a diagram illustrating a state in which the pair of plate members 252b according to the second embodiment are closed. As shown in FIG. 20, when the floating body 250 (added mass portion 252) rises above the water, water resistance is generated downward against the pair of plate members 252b, causing each of the pair of plate members 252b to rotate about the hinge 252a. This increases the distance between the pair of plate members 252b. As a result, the water resistance against the pair of plate members 252b further increases, and the period of the up-and-down movement of the floating body 250 can be increased (for example, to one second or more).

[0057] As shown in Figure 21, when the floating body 250 (additional mass 252) sinks in water, water resistance is generated upward against the pair of plate members 252b, causing each of the pair of plate members 252b to rotate relative to the hinge 252a. This narrows the gap between the pair of plate members 252b. As a result, water resistance against the pair of plate members 252b decreases, causing the floating body 250 to sink deeper into the water and increasing the amount of movement of the floating body 250. This increases the amount of power generated by the wave power generator 210. Other configurations of the second embodiment are the same as those of the first embodiment.

[0058] [Modification of the second embodiment] Next, a wave power generator according to a modification of the second embodiment will be described with reference to FIG.

[0059] (Ninth Modification) FIG. 22 is a diagram showing the configuration of a float 250a according to a modification (ninth modification) of the second embodiment. As shown in FIG. 22, the float 250a includes a float portion 251a. When viewed from the front (viewed in the Y2 direction), the float portion 251a has a pair of side surfaces 251aa that are inclined downward to approach each other. When the float 250 (added mass portion 252) sinks in water, the pair of plate members 252b each rotates about the hinge 252a and abuts against the pair of side surfaces 251aa. This allows water to flow continuously from the pair of plate members 252b to the pair of side surfaces 251aa, thereby reducing water resistance to the float 250a. As a result, the float 250a sinks deeper into the water, increasing the amount of movement of the float 250a.

[0060] [Third embodiment] Next, the configuration of a wave power generator 310 according to a third embodiment will be described with reference to Figure 23. Figure 23 is a side view showing the configuration of the wave power generator 310 according to the third embodiment. As shown in Figure 23, the wave power generator 310 includes a member 372. The member 372 is connected to the upper trolley 71a and the lower trolley 71b. The member 372 has a portion 372aa that extends downward beyond the lower end 71ba of the lower trolley 71b. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

[0061] As shown in Figure 23, the portion 372aa is fixed to the upper part of the float 50. As a result, the float 50 according to the third embodiment is positioned below the lower end 71ba of the lower trolley 71b. This allows the upper trolley 71a and the lower trolley 71b to be positioned above the waterline WL, thereby preventing deterioration (corrosion) of the upper trolley 71a and the lower trolley 71b due to water. The other configurations according to the third embodiment are the same as those of the first embodiment.

[0062] [Modification of the third embodiment] Next, a wave power generator according to a modification of the third embodiment will be described with reference to FIGS.

[0063] (Tenth Modification) FIG. 24 is a diagram showing the configuration of a wave power generator 310a according to a modification (tenth modification) of the third embodiment. As shown in FIG. 24, the wave power generator 310a includes a member 372a. The member 372a is connected to the upper trolley 71a and the lower trolley 71b. The member 372a has a portion 372ab that extends downward from the lower end 71ba of the lower trolley 71b. The portion 372ab has a portion that extends toward the offshore side (in the Y1 direction) and a portion that extends downward from the portion that extends toward the offshore side. The downward extending portion is fixed to the upper part of the float 50. As a result, the float 50 is positioned below the lower end 71ba of the lower trolley 71b.

[0064] (Eleventh Modification) FIG. 25 is a diagram showing the configuration of a wave power generator 310b according to a modification (eleventh modification) of the third embodiment. As shown in FIG. 25, the wave power generator 310b includes a member 372b and a member 372c. The member 372b is connected to the upper trolley 71a and the lower trolley 71b. The member 372b is L-shaped. A corner 372ba of the member 372b is located on the offshore side (Y1 direction side). The member 372c extends from the corner 372ba downward beyond the lower end 71ba of the lower trolley 71b. The float 50 is connected to the member 372c and is located below the lower end 71ba of the lower trolley 71b.

[0065] (Twelfth Modification) Figure 26 is a diagram showing the configuration of a wave power generator 310c according to a modification (twelfth modification) of the third embodiment. As shown in Figure 26, the wave power generator 310c includes members 372d and 372e in addition to the configuration of the eleventh modification. Member 372d is fixed to member 372b and extends in the vertical direction. Member 372e is formed across members 372b and 372c. This reinforces members 372b and 372c in the configuration of the eleventh modification.

[0066] [Fourth embodiment] Next, the configuration of a wave power generator 410 according to a fourth embodiment will be described with reference to Figure 27. Figure 27 is a cross-sectional view showing the configuration of the wave power generator 410 according to the fourth embodiment. As shown in Figure 27, the wave power generator 410 includes a floating body 450. The floating body 450 includes a float portion 451, an additional mass portion 452, and a float portion 453. The float portion 453 is fixed below the additional mass portion 452. The specific gravity of the float portion 453 is smaller than the specific gravity of water. For example, air is sealed inside the float portion 453. The additional mass portion 452 is provided with a plurality of holes 452a that allow water to pass through. The remaining configuration of the fourth embodiment is similar to that of the first embodiment.

[0067] [Fifth embodiment] Next, the configuration of a wave power generator 510 according to a fifth embodiment will be described with reference to Figure 28. Figure 28 is a cross-sectional view showing the configuration of a wave power generator 510 according to the fifth embodiment. As shown in Figure 28, the wave power generator 510 includes a floating body 550. The floating body 550 includes a float portion 551 and an additional mass portion 552. The additional mass portion 552 has a columnar shape that protrudes downward from the float portion 551. The horizontal width W52 of the additional mass portion 552 is smaller than the width W51 of the float portion 551. As a result, the specific gravity of the additional mass portion 552 is greater than the specific gravity of water. The remaining configuration of the fifth embodiment is similar to that of the first embodiment.

[0068] [Modification of the fifth embodiment] Next, a floating body according to a modification of the fifth embodiment will be described with reference to FIGS.

[0069] (13th Modification) 29 is a diagram showing the configuration of a float 550a according to a modification (thirteenth modification) of the fifth embodiment. The float 550a includes a float portion 551a and an added mass portion 552a. The float portion 551a has a shape that gradually narrows downward. The added mass portion 552a is formed in a rod shape that protrudes downward from the float portion 551a.

[0070] (14th Modification) 30 is a diagram showing the configuration of a float 550b according to a modification (fourteenth modification) of the fifth embodiment. The float 550b includes a float portion 551b and an added mass portion 552b. The float portion 551b has a rectangular box shape. The added mass portion 552a is formed in a rod shape that protrudes downward from the float portion 551a.

[0071] [Sixth embodiment] Next, the configuration of a wave power generator 610 according to the sixth embodiment will be described with reference to FIG. 31. FIG. 31 is a cross-sectional view showing the configuration of the wave power generator 610 according to the sixth embodiment. As shown in FIG. 31, the wave power generator 610 includes a float 650. The float 650 includes a float portion 651 and an additional mass portion 652a. The additional mass portion 652a has a first portion 652aa extending downward from the float portion 651 and a second portion 652ab protruding horizontally into the water from the first portion 652aa. When the second portion 652ab moves up and down, the surrounding water acts as resistance, so the natural vibration period of the up and down movement of the float 650 relative to the water surface W can easily be set to 1 second or more. Note that the other configurations of the sixth embodiment are similar to those of the first embodiment.

[0072] [Modification of the sixth embodiment] Next, a floating body according to a modification of the sixth embodiment will be described with reference to FIGS.

[0073] (15th Modification) 32 is a diagram showing the configuration of a wave power generator 610a according to a modification (15th modification) of the sixth embodiment. The wave power generator 610a includes a floating body 650a. The floating body 650a includes a float portion 651a and an additional mass portion 652b. The additional mass portion 652b has a first portion 652ba extending downward from the float portion 651a and a second portion 652bb protruding horizontally into the water from the first portion 652ba. The second portion 652bb has a circular cross section.

[0074] (16th Modification) Figure 33 is a diagram showing the configuration of a wave power generator 610b according to a modification (sixteenth modification) of the sixth embodiment. The wave power generator 610b includes a float 650b. The float 650b includes a float portion 651b and an additional mass portion 652c. The additional mass portion 652c has a first portion 652ca extending downward from the float portion 651b, and a second portion 652cb protruding horizontally into the water from the first portion 652ca. The second portion 652cb has a diamond-shaped cross section.

[0075] [Seventh embodiment] Next, the configuration of a float 750 according to the seventh embodiment will be described with reference to Figures 34 and 35. Figures 34 and 35 are diagrams showing the configuration of a wave power generator 610 according to the seventh embodiment. As shown in Figure 34, the float 750 includes a float portion 751 and an additional mass portion 752. The additional mass portion 752 has a frame shape extending downward from the float portion 651. Water is contained inside the additional mass portion 752 (within the frame). As shown in Figure 35, the additional mass portion 752 has a rectangular shape when viewed from above (in the Z1 direction). The other configurations of the seventh embodiment are similar to those of the first embodiment.

[0076] [Modification of the Seventh Embodiment] Next, a floating body according to a modification of the seventh embodiment will be described with reference to FIGS.

[0077] (17th Modification) Figure 36 is a diagram showing the configuration of a floating body 750a according to a modification (seventeenth modification) of the seventh embodiment. The floating body 750a includes a float portion 751 and an additional mass portion 752a. As shown in Figure 36, the additional mass portion 752a has a zigzag frame shape when viewed from below.

[0078] (18th Modification) Figure 37 is a diagram showing the configuration of a float 750b according to a modification (18th modification) of the seventh embodiment. The float 750b includes a float portion 751 and an additional mass portion 752b. As shown in Figure 37, the additional mass portion 752b has an X-shape when viewed from below.

[0079] (19th Modification) Figure 38 is a diagram showing the configuration of a float 750c according to a modification (19th modification) of the seventh embodiment. The float 750c includes a float portion 751 and an added mass portion 752c. As shown in Figure 38, the added mass portion 752c includes multiple L-shaped portions that protrude inward.

[0080] (20th Modification) Figure 39 is a diagram showing the configuration of a float 750d according to a modification (20th modification) of the seventh embodiment. The float 750d includes a float portion 751 and an added mass portion 752d. As shown in Figure 39, the added mass portion 752d includes a plurality of L-shaped portions 752db that protrude inward, and a plurality of plate members 752da that surround the portions 752db.

[0081] [Modifications of the first to seventh embodiments] (21st Modification) Next, the configuration of a wave power generator 810 according to a 21st modification will be described with reference to Fig. 40. Fig. 40 is a diagram showing the configuration of a wave power generator 810 according to a 21st modification. In the first to seventh embodiments, examples have been shown in which the period of the up and down movement of the float relative to the water surface is set to be between 1 second and 15 seconds, but as shown in Fig. 40, the period Tn2 of the up and down movement of the float of the wave power generator 810 relative to the water surface may be set to be longer than 15 seconds.

[0082] (22nd Modification) Next, the configuration of a wave power generator 910 according to a 22nd modified example will be described with reference to FIGS. 41 and 42. FIGS. 41 and 42 are diagrams showing the configuration of a wave power generator 910 according to a 22nd modified example. In the first to seventh embodiments, an example was described in which the distance between the upper trolley 71a and the lower trolley 71b was greater than the vertical length of the float, but the present disclosure is not limited to this. As shown in FIG. 41, the distance L11 between the upper trolley 971a and the lower trolley 971b may be less than the vertical length L12 of the float 950. Furthermore, the protruding length L13 of the float 950 from the rail member 70 is greater than the distance L11 between the upper trolley 971a and the lower trolley 971b. This increases the frictional force between the upper trolley 971a and the lower trolley 971b and the rail member 70, making it more difficult for the container 952 of the float 950 to move vertically (the vertical period increases).

[0083] As shown in FIG. 41, the float 950 includes a float unit 951, a container 952, and a float member 953. The float unit 953 is fixed to the container 952 and keeps the container 952 afloat on the water surface. The container 952 is fixed to a support member 972 to which an upper trolley 971a and a lower trolley 971b are fixed. The specific gravity of the support member 972 is smaller than the specific gravity of water, providing buoyancy to the float 950. As shown in FIG. 42, rollers 954 are disposed between the float unit 951 and the container 952, and the float unit 951 and the container 952 move relative to each other in the vertical direction. The period of the up-and-down movement of the float unit 951 relative to the water surface is shorter than the period of the up-and-down movement of the container 952 relative to the water surface. As a result, as shown in FIG. 41, when the water surface height changes from h1 to h2, the float part 951 rises, while the height position of the container 952 does not change.

[0084] As rack gear 955 fixed to float portion 951 moves, gear 956 fixed to housing 952 rotates, and electricity is generated by a power generating device connected to gear 956. Note that, as a technology that can rotate the turbine in the power generating device in the same direction regardless of whether rack gear 955 moves up or down, the technology described in Japanese Patent No. 7682507 can be used, for example. Rack gear 955 and gear 956 function as a "conversion mechanism" that converts the up and down movement of float portion 951 into rotational movement.

[0085] (23rd Modification) Next, the configuration of a wave power generator 1010 according to the 23rd modified example will be described with reference to Fig. 43. Fig. 43 is a diagram showing the configuration of the wave power generator 1010 according to the 23rd modified example. As in the wave power generator 1010 shown in Fig. 43, a plurality of floats 1050 may be fixed in a line to a single member 1072 that is fixed to a plurality of trolleys 1071. The float 1050 has, for example, the same configuration as the float 950 according to the 22nd modified example, but may also have the configuration of another float, such as the float 50 of the first embodiment.

[0086] [Variations] The above-described embodiments are merely examples for carrying out the present disclosure. Therefore, the present disclosure is not limited to the above-described embodiments, and the above-described embodiments can be appropriately modified and carried out without departing from the spirit of the present disclosure. Furthermore, each of the above-described embodiments (first to seventh embodiments) and each of the modifications (first to twenty-third modifications) may be combined in any way, and the modifications shown below may also be combined.

[0087] (1) In the above embodiment and modified example, the power converter and the storage battery are provided outside the wave power generation system, but the present disclosure is not limited to this. For example, at least one of the power converter and the storage battery may be provided inside the wave power generation system (wave power generation device).

[0088] (2) In the above embodiment and modified example, the power generation device is disposed inside the housing 20, but the present disclosure is not limited to this. That is, the power generation device may be disposed outside the housing (for example, on a quay).

[0089] (3) In the above embodiment and modified example, the wave power generation device is mounted on a rail member fixed to the shore, but the present disclosure is not limited to this. For example, the wave power generation device may be mounted on a rail that extends in the vertical direction and is fixed to the seabed.

[0090] (4) In the above embodiment and modified examples, examples of the shape of the added mass portion have been shown, but the present disclosure is not limited to this. (Modified Example 24) For example, an added mass portion 1152 having a rectangular parallelepiped shape may be provided, as in the float 1150 according to Modified Example 24 shown in Fig. 44. The added mass portion 1152 has an internal space, and a weight 1152a is disposed in this space. The weight 1152a is made of, for example, metal, and the specific gravity of the added mass portion 1152 is greater than the specific gravity of water.

[0091] (5) In the wave power generator 910 according to the twenty-second modified example, an example in which a support member 972 is provided has been described above, but the present disclosure is not limited to this. (Twenty-fifth Modification) For example, as in a wave power generator 1210 according to the twenty-fifth modified example shown in FIG. 45, the housing 952 of the float 950 may be directly fixed to the upper trolley 1271a and the lower trolley 1271b (the support member 972 may not be provided). (Twenty-sixth Modification) As in a wave power generator 1310 according to the twenty-sixth modified example shown in FIG. 46, the float 1350 may be directly fixed to the upper trolley 1271a and the lower trolley 1271b. The wave power generator 1310 also has a plurality of floats 1350. The plurality of floats 1350 are arranged side by side (connected) from the quay S toward the sea. The length L21 of the multiple floating bodies 1350 in the direction from the quay S toward the open sea is greater than half the wavelength of waves having the average wave height at the location where they are installed. In addition, the length L22 of the float parts 1351 of the multiple floating bodies 1350 in the direction from the quay S toward the open sea is less than half the wavelength of the waves. As a result, the multiple floating bodies 1350 follow the ebb and flow of the tides rather than the waves, and the float parts 1351 follow the movement of the water surface W caused by the waves.

[0092] (27th Modification) As in the wave power generation device 1410 according to the 27th modified example shown in Figure 47, multiple floating bodies 950 may be arranged side by side along a quay S, and each of the multiple floating bodies 950 may be fixed to a trolley 1471.

[0093] (28th Variation) 48, a plurality of floating bodies 950 may be arranged in a matrix when viewed from above, and may be fixed to one another. Of the plurality of floating bodies 950, the floating body 950 closest to the quay wall S is fixed to the trolley 1471.

[0094] (6) In the wave power generator 910 according to the twenty-second modified example, one support member 972 is provided for one floating body 950, but the present disclosure is not limited to this. For example, as in the wave power generator 1610 according to the twenty-ninth modified example shown in Fig. 49, one support member 1672 is provided for multiple floating bodies 950. Multiple floating bodies 950 are fixed to the support member 1672. The support member 1672 is arranged on a rail member (not shown) via multiple trolleys 1671.

[0095] The present disclosure can also be explained as follows.

[0096] A wave power generator according to a first configuration comprises a float, at least a portion of which is capable of floating on the water surface and which moves up and down in response to changes in the water surface position due to waves, a conversion mechanism that converts the up and down motion of the float into rotational motion, and a power generation unit that converts the rotational motion converted by the conversion mechanism into electric power. The natural vibration period of the up and down motion of the float relative to the water surface is set to be between 1 second and 15 seconds (first configuration).

[0097] According to the first configuration, during periods when relatively small waves (waves with a period of 1 second to 15 seconds) are generated, the float resonates with the waves, resulting in a movement amount greater than the movement amount of the water surface. As a result, even during periods when relatively small waves are generated, the float can be moved by a large amount, thereby generating a large rotational motion in the power generation unit. This allows power to be generated even during periods when small waves are generated. Furthermore, during periods when relatively large waves (waves with a period of more than 15 seconds) are generated, even if the float does not resonate, the float moves in response to the large waves, resulting in a large movement amount of the float. As a result, during both periods when relatively small waves are generated and periods when relatively large waves are generated, a large rotational motion can be generated in the power generation unit, thereby increasing the amount of power generation. Furthermore, with fine waves (waves with a period of less than 1 second), even if the float resonates with the wave motion, it is not possible to ensure a movement amount of the float sufficient to contribute to power generation. In contrast, in the first embodiment, the natural vibration period of the floating body's up and down motion relative to the water surface is set to 1 second or more, so the floating body's motion can be resonated with small waves (not too fine waves) that contribute to power generation, thereby increasing the amount of power generation.

[0098] In the first configuration, the floating body may include a float portion having a specific gravity less than that of water, and an additional mass portion disposed below the waterline of the float portion and moving up and down integrally with the float portion. The mass of the additional mass portion may be configured to be greater than the mass of the float portion (second configuration).

[0099] According to the second configuration, even if the float part of the float is lightweight, the natural vibration period of the float's up and down movement relative to the water surface can be set to one second or more.

[0100] In the second configuration, the length of the additional mass in the vertical direction may be greater than the length of the float portion in the vertical direction (third configuration).

[0101] According to the third configuration, the vertical dimension of the additional mass portion is large, so the mass of the additional mass portion can be made greater than the mass of the float portion without using (or with a small amount of) other heavy materials.

[0102] In the second or third configuration, the additional mass may include a container in which water is placed and which has holes through which the water passes (fourth configuration).

[0103] According to the fourth configuration, the water that has entered the container can be configured as part of the mass of the added mass portion, so that the material that configures the added mass portion can be reduced.

[0104] In any one of the second to fourth configurations, the added mass portion may have a first portion extending downward from the floating body and a second portion protruding horizontally into the water from the first portion (fifth configuration).

[0105] According to the fifth configuration, when the second part moves up and down, the surrounding water acts as resistance, so that the natural vibration period of the floating body's up and down movement relative to the water surface can easily be made to be one second or more.

[0106] In any one of the second to fifth configurations, the added mass may be configured so that the lower surface thereof slopes upward toward the sea (sixth configuration).

[0107] According to the sixth configuration, the added mass is lifted by waves coming from offshore toward the shore, so that the amount of movement of the floating body can be increased.

[0108] In any one of the second to sixth configurations, the additional mass may be configured to have a shape that gradually tapers downward (seventh configuration).

[0109] According to the seventh configuration, the resistance of the water can be reduced when the float sinks (moves downward), so that the float sinks to a deeper position and the amount of movement of the float can be increased.

[0110] In any one of the second to seventh configurations, the added mass may include a hinge and a pair of plate members rotatably connected to the hinge. The pair of plate members may be configured such that the gap between the pair of plate members narrows when the added mass is submerged in water and widens when the added mass rises above the water (eighth configuration).

[0111] According to the eighth configuration, when the added mass sinks in water, the gap between the pair of plate members narrows, so that when the float sinks (moves downward), the water resistance can be reduced and the amount of movement of the float can be increased. As a result, the amount of power generation can be increased. Furthermore, when the added mass rises above the water, the gap between the pair of plate members widens, so that the water resistance against the upward movement of the pair of plate members can be increased. This allows the amount of movement of the float to be increased while using the water resistance to set the natural vibration period of the float's up and down movement relative to the water surface to one second or more.

[0112] In any one of the second to eighth configurations, the wave power generator may further include rails fixed to the shore and extending in the vertical direction, and upper and lower trolleys that move along the rails. The floating body may be fixed to the upper and lower trolleys. The distance between the upper and lower trolleys may be configured to be greater than the vertical length of the floating body (ninth configuration).

[0113] Here, when a float is arranged to be movable vertically via an upper trolley and a lower trolley relative to a rail fixed to the shore, waves pushing up the float push up the portion of the float opposite the rail (offshore side). Therefore, a force (moment) is applied to the float in the direction of rotation around the upper trolley and the lower trolley, increasing the frictional force between the upper trolley and the lower trolley and the rail. This results in a problem in that the upper trolley and the lower trolley are difficult to move vertically relative to the rail. In contrast, with the ninth configuration, the distance between the upper trolley and the lower trolley is greater than the vertical length of the float, thereby reducing the moment acting on the float centered around the upper trolley and the lower trolley. As a result, the frictional force between the upper trolley and the lower trolley and the rail can be reduced, allowing the float to move smoothly relative to the rail and increasing the amount of power generation.

[0114] In the ninth configuration, the distance between the upper trolley and the lower trolley may be configured to be greater than the length by which the floating body protrudes from the upper trolley toward the open sea, and greater than the length by which the floating body protrudes from the lower trolley toward the open sea (tenth configuration).

[0115] According to the tenth configuration, the force (moment) acting in the direction of rotation of the floating body around the upper trolley and the lower trolley can be reduced, which allows the floating body to move smoothly relative to the rails, thereby increasing the amount of power generation.

[0116] In the ninth or tenth configuration, the wave power generator may further include a string-, band-, or chain-like motion transmission member connecting the float and the conversion mechanism. The motion transmission member may be connected to the float at a position closer to the rail-side end of the float than to the offshore end of the float (eleventh configuration).

[0117] According to the above 11th configuration, even if a force that pulls the float upward is generated by the motion transmission member, the force (moment) in the direction in which the float rotates around the upper trolley and the lower trolley can be reduced.

[0118] In any one of the ninth to eleventh configurations, the floating body may be disposed at a position below the lower end of the lower trolley (twelfth configuration).

[0119] According to the twelfth configuration, the upper trolley and the lower trolley can be disposed above the water line, so that deterioration (corrosion) of the upper trolley and the lower trolley due to water can be prevented.

[0120] In any one of the ninth to eleventh configurations, the floating body may be disposed at a position below the upper end of the upper trolley and above the lower end of the lower trolley (thirteenth configuration).

[0121] According to the thirteenth configuration, the floating body can be disposed in a position close to both the upper trolley and the lower trolley, thereby making it possible to reduce the size of the wave power generation device.

[0122] In any one of the ninth to thirteenth configurations, the wave power generator may further include a pillar member connecting the upper trolley and an offshore portion of the floating body (fourteenth configuration).

[0123] According to the fourteenth configuration, when the offshore portion of the floating body is lifted by waves, the force can be transmitted to the upper trolley by the pillar members.

[0124] A wave power generator according to a fifteenth configuration comprises a float, at least a portion of which is capable of floating on the water surface and which moves up and down in response to changes in the water surface position caused by waves, a conversion mechanism that converts the up and down movement of the float into rotational movement, a power generation unit that converts the rotational movement converted by the conversion mechanism into electric power, rails fixed to the shore and extending in the vertical direction, and an upper trolley and a lower trolley that move along the rails. The float is fixed to the upper trolley and the lower trolley. The distance between the upper trolley and the lower trolley is greater than the vertical length of the float (fifteenth configuration).

[0125] Here, when a float is arranged to be movable vertically via an upper trolley and a lower trolley relative to a rail fixed to the shore, waves pushing up the float push up the portion of the float opposite the rail (offshore side). Therefore, a force (moment) is applied to the float in the direction of rotation around the upper trolley, increasing the frictional force between the upper trolley and the lower trolley and the rail. As a result, there is a problem in that the upper trolley and the lower trolley are difficult to move vertically relative to the rail. In contrast, with the fifteenth configuration, the distance between the upper trolley and the lower trolley is greater than the vertical length of the float, thereby reducing the moment acting on the float centered around the upper trolley and the lower trolley. As a result, the frictional force between the upper trolley and the lower trolley and the rail can be reduced, allowing the float to move smoothly relative to the rail and increasing the amount of power generation. [Explanation of symbols]

[0126] 10: wave power generator, 10a: wave power generator, 10b: wave power generator, 10c: wave power generator, 10d: wave power generator, 10e: wave power generator, 10f: wave power generator, 10g: wave power generator, 10h: wave power generator, 12: container, 20: container, 20a: bottom plate, 20b: hole, 20c: hole, 21: generator, 22: flywheel, 23: gearbox, 23a: ratchet gear, 23b: gear, 23c: shaft, 23d: gear, 23e: gear, 23f: ratchet gear, 24: shaft, 25: shaft, 26: shaft, 27: beam member, 28: box material, 29: container, 29a: upper surface, 31: pulley, 32: pulley, 33: pulley, 34: pulley, 40: rope, 41: first part, 42: second part, 43: third part, 44: fourth part, 45: fifth part, 47: end part, 50: float, 50a: float, 50b: float, 50c: float, 50d: float, 50e: float, 50f: float, 50g: float, 50h: float, 51: float part, 52: added mass part, 52a: lower surface, 52b: side, 52c: hole part, 53: hook, 54: hook, 55: end part, 60: sinker, 61: hook, 62: upper surface, 63: lower surface, 70: rail member, 71: Trolley, 71a: upper trolley, 71aa: upper end, 71b: lower trolley, 71ba: lower end, 72: member, 80: elastic member, 100: wave power generation system, 101: power conversion device, 102: equipment, 103: storage battery, 151h: float part, 151ha: upper surface, 152a: added mass part, 152b: added mass part, 152c: added mass part, 152d: added mass part, 152e: added mass part, 152f: added mass part, 152g: added mass part, 152ga: hole part, 210: wave power generation device, 250: float, 250a: float, 251a: float part, 251aa: side surface , 252: added mass portion, 252a: hinge, 252b: plate member, 310: wave power generation device, 310a: wave power generation device, 310b: wave power generation device, 310c: wave power generation device, 372: member, 372a: member, 372aa: part, 372ab: part, 372b: member, 372ba: corner portion, 372c: member, 372d: member, 372e: member, 410: wave power generation device, 450: float, 451: float portion, 452: added mass portion, 452a: hole portion, 453: float portion, 510: wave power generation device, 550: float, 550a: float, 550b: float, 551: float portion,551a: float portion, 551b: float portion, 552: added mass portion, 552a: added mass portion, 552b: added mass portion, 610: wave power generation device, 610a: wave power generation device, 610b: wave power generation device, 650: float, 650a: float, 650b: float, 651: float portion, 651a: float portion, 651b: float portion, 652a: added mass portion, 652aa: first portion, 652ab: second portion, 652b: additional mass portion, 652ba: first portion, 652bb: second portion, 652c: additional mass portion, 652ca: first portion, 652cb: second portion, 750: floating body, 750a: floating body, 750b: floating body, 750c: floating body, 750d: floating body, 751: float portion, 752: additional mass portion, 752a: additional mass portion, 752b: additional mass portion, 752c: additional mass portion, 752d: additional mass portion, 752da: plate member , 752db: part, 810: wave power generation device, 910: wave power generation device, 950: floating body, 951: float part, 952: container, 953: float part, 954: roller, 955: rack gear, 956: gear, 971a: upper trolley, 971b: lower trolley, 972: support member, 1010: wave power generation device, 1050: floating body, 1071: trolley, 1072: member, 1150: floating body, 11 52: added mass, 1210: wave power generator, 1271a: upper trolley, 1271b: lower trolley, 1310: wave power generator, 1350: floating body, 1351: float part, 1410: wave power generator, 1471: trolley, 1510: wave power generator, 1610: wave power generator, 1671: trolley, 1672: support member, 15410: wave power generator, S: quay, W: water surface, WL: waterline,

Claims

1. a floating body at least a portion of which is capable of floating on the water surface and which moves up and down in response to changes in the water surface position caused by waves; a conversion mechanism for converting the up and down motion of the floating body into rotational motion; a power generation unit that converts the rotational motion converted by the conversion mechanism unit into electric power; Rails fixed to the shore and extending vertically; an upper trolley and a lower trolley that move along the rails; The natural vibration period of the up and down movement of the floating body relative to the water surface is set to be 1 second or more and 15 seconds or less, the floating body is fixed to the upper trolley and the lower trolley; The distance between the upper trolley and the lower trolley is greater than the vertical length of the floating body; The floating body includes a float portion having a specific gravity smaller than that of water, A wave power generation device in which the length of the float section protruding from the upper trolley toward the sea is shorter than the distance between the upper trolley and the lower trolley and is longer than the vertical length of the float section.

2. the floating body includes an added mass portion that is disposed below the waterline of the float portion and moves up and down integrally with the float portion, The wave power generator according to claim 1 , wherein the mass of the additional mass portion is greater than the mass of the float portion.

3. The wave power generator according to claim 2 , wherein the vertical length of the additional mass portion is greater than the vertical length of the float portion.

4. 3. The wave power generator according to claim 2, wherein the additional mass portion includes a container in which water is placed and which has holes through which the water passes.

5. 3. The wave power generator according to claim 2, wherein the added mass has a first portion extending downward from the floating body and a second portion protruding horizontally from the first portion into the water.

6. The wave power generator according to claim 2 , wherein the bottom surface of the added mass is inclined upward toward the ocean.

7. The wave power generator according to claim 2 , wherein the additional mass portion has a shape that gradually tapers downward.

8. The additional mass portion is Hinge and a pair of plate members rotatably connected to the hinge, 3. The wave power generation device according to claim 2, wherein the gap between the pair of plate members narrows when the additional mass portion sinks in water, and the gap between the pair of plate members widens when the additional mass portion rises above the water.

9. a floating body at least a portion of which is capable of floating on the water surface and which moves up and down in response to changes in the water surface position caused by waves; a conversion mechanism for converting the up and down motion of the floating body into rotational motion; a power generation unit that converts the rotational motion converted by the conversion mechanism unit into electric power; Rails fixed to the shore and extending vertically; an upper trolley and a lower trolley that move along the rails; a string-like, belt-like, or chain-like motion transmission member that connects the floating body and the conversion mechanism, the floating body is fixed to the upper trolley and the lower trolley; The distance between the upper trolley and the lower trolley is greater than the vertical length of the floating body; A wave power generation device, wherein the motion transmission member is connected to the float at a position closer to the rail-side end of the float than to the offshore end of the float.

10. The wave power generation device according to claim 1 , wherein the floating body is disposed at a position below a lower end of the lower trolley.

11. 2. The wave power generation device according to claim 1, wherein the floating body is disposed at a position below an upper end of the upper trolley and above a lower end of the lower trolley.

12. The wave power generation device according to claim 1 , further comprising a column member connecting the upper trolley and an offshore portion of the floating body.

13. a floating body at least a portion of which is capable of floating on the water surface and which moves up and down in response to changes in the water surface position caused by waves; a conversion mechanism for converting the up and down motion of the floating body into rotational motion; a power generation unit that converts the rotational motion converted by the conversion mechanism unit into electric power; Rails fixed to the shore and extending vertically; an upper trolley and a lower trolley that move along the rails; the floating body is fixed to the upper trolley and the lower trolley; The distance between the upper trolley and the lower trolley is greater than the vertical length of the floating body; The floating body includes a float portion having a specific gravity smaller than that of water, A wave power generation device in which the length of the float section protruding from the upper trolley toward the sea is shorter than the distance between the upper trolley and the lower trolley and is longer than the vertical length of the float section.

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