Floating Structure

Abstract

To provide a float structure capable of stably floating on a water surface by effectively suppressing oscillation by waves as well as excelling in maintainability and transportability in a simple and compact constitution.SOLUTION: A float structure 10 floating on a water surface includes: a float 12 that is provided with a float body 16 with its top surface appearing on the water surface and a float projection 18 provided projecting downward from the bottom of the float body 16; and a swing suppression plate 14 that is provided around the float projection 18 and more inside than the outer periphery surface of the float body 16 and suppresses the swing due to waves.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a floating structure that floats on the water surface. [Background technology]

[0002] Floating structures that float on the water surface have been widely used as facilities on water in the ocean, lakes, rivers, etc. (see Patent Document 1). Such floating structures do not require the installation of supports on the water bottom, making their structure simple and low-cost, but they have a problem of being affected by motion caused by waves. Therefore, there is a demand for a floating structure that can suppress motion caused by waves and float stably on the water surface.

[0003] Specific examples of such floating structures include observation buoys for the purposes of marine meteorological observation, wave and tsunami observation, wind observation, seawater survey, and environmental survey in the fisheries and aquaculture industries (see Patent Document 2). For observation buoys, in addition to suppressing motion caused by waves, a buoy with a large volume capable of mounting such equipment is desired in order to increase the number of observation sensors and ensure a power source for long-term observation. In addition, a buoy with high maintainability that allows maintenance of the mounted equipment to be performed at sea is desired. Furthermore, a buoy with a low cost and simple structure that can be used for land and water transportation is desired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-029065 A [Patent Document 2] JP 2001-341693 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a floating structure that can efficiently suppress rocking caused by waves and float stably on the water surface, while having a simple and compact configuration and excellent maintainability and transportability. [Means for solving the problem]

[0006] As a result of intensive research into solving the above-mentioned problems, the inventors discovered that the above-mentioned problems could be solved by configuring a float comprising a float main body and a float convex portion protruding downwardly from the float (a shape in which the lower peripheral portion of the float is missing), and providing a motion suppression plate around the float convex portion and inward from the outer periphery of the float main body, thereby completing the present invention.

[0007] That is, the present invention is as follows. [1] A floating structure that floats on the water surface, A float including a float body whose upper surface appears above water and a float convex portion protruding downward from a lower portion of the float body; A motion suppression plate is provided around the floating protrusion and inward from the outer circumferential surface of the floating body to suppress motion caused by waves; A floating structure comprising: [2] The floating structure described in [1] above, characterized in that the motion suppression plate is a horizontal plate extending in the circumferential direction and spaced outward from the lower side of the floating convex portion. [3] The floating structure described in [1] above, characterized in that the motion suppression plate is a vertical plate extending in the circumferential direction and spaced downward from the outer bottom of the floating body. [4] The floating structure according to [2] or [3] above, characterized in that the motion suppression plate is provided above the bottom surface of the floating convex portion. [5] The floating structure according to any one of the above [1] to [4], wherein the floating body and the floating convex portion are each cylindrical. [6] The floating structure according to any one of the above [1] to [5], which is an observation buoy. Effect of the Invention

[0008] The floating structure of the present invention is capable of efficiently suppressing rocking caused by waves and floating stably on the water surface, and has a simple and compact structure that is easy to maintain and transport. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic side cross-sectional view of a floating body structure according to a first embodiment of the present invention. [Diagram 2] 2 is a schematic cross-sectional view taken along line AA of the floating structure according to the first embodiment shown in FIG. 1. [Diagram 3] FIG. 1 is an explanatory diagram showing a floating structure according to a first embodiment of the present invention floating on the sea, where (a) shows a state in which it is moored at two points, and (b) shows a state in which it is moored at one point. [Figure 4] FIG. 4 is a schematic side cross-sectional view of a floating body structure according to a second embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic end view of the floating structure according to the second embodiment shown in FIG. 4 taken along line BB. [Figure 6] FIG. 11 is a schematic side cross-sectional view of a float of a floating body structure according to a third embodiment of the present invention. [Figure 7] FIG. 11 is a schematic cross-sectional side view of a float of a floating body structure according to a fourth embodiment of the present invention. [Figure 8] 13 is a photograph showing a floating body of a floating structure according to a fifth embodiment produced in an example. [Figure 9] 13 is a photograph showing a floating body structure according to a fifth embodiment produced in an example, where (a) is a photograph taken obliquely from above, and (b) is a photograph taken obliquely from below. [Figure 10] 13 is a photograph showing a floating body structure according to a sixth embodiment produced in an example, where (a) is a photograph taken obliquely from above, and (b) is a photograph taken obliquely from below. [Figure 11] Photographs showing a conventional floating structure produced in the embodiment, where (a) is a photograph taken obliquely from above, and (b) is a photograph taken obliquely from below. [Figure 12] FIG. 2 is an explanatory diagram showing an outline of a vibration characteristic test. [Figure 13]FIG. 13 is a diagram showing the results of measuring the motion characteristics of the floating structure produced in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The floating structure of the present invention is a floating structure that floats on the water surface, and is characterized in that it comprises a float having a floating body whose upper surface appears above the water, a floating convex portion protruding downward from the lower portion of the floating body, and a motion suppression plate that is arranged around the floating convex portion and inward from the outer peripheral surface of the floating body, and suppresses motion caused by waves.

[0011] In this specification, the movement of a floating structure around an axis perpendicular to the direction in which the waves approach is referred to as pitching (swaying in the pitch direction), and the movement of a floating structure around an axis parallel to the direction in which the waves approach is referred to as lateral swaying (swaying in the roll direction).

[0012] In the floating structure of the present invention, the motion suppression plate provided around the float protruding portion provides resistance to the fluid flow at the bottom of the floating structure caused by vertical or horizontal motion due to waves, thereby suppressing motion and enabling stable floating. In addition, compared to conventional floats, since the shape is such that only a small part, such as the lower periphery of the float, is missing, sufficient internal space can be secured and the structure can float stably. In addition, since the motion suppression plate is provided inside the outer periphery of the float body, the structure is compact and the risk of interference with the outside caused by the motion suppression plate can be reduced. In other words, when floating on the water surface, a maintenance ship or the like can be brought close to the structure, making maintenance on the water easier. In addition, when the structure is towed by a ship or the like and moves on the water surface, it can be towed smoothly without resistance. Furthermore, when the structure is loaded onto a truck or ship for transportation, it can be transported efficiently without risk of damage.

[0013] The floating structure of the present invention can be applied, for example, to observation buoys for obtaining information related to meteorology, ocean conditions, and the fishing industry, as well as navigational buoys, construction marker buoys, floating piers, barges, etc.

[0014] Methods for installing the floating structure of the present invention include multi-point mooring, which is excellent at maintaining position against external forces such as wind, waves, and currents, and single-point mooring, which swings around to reduce the force received from external forces.

[0015] Hereinafter, the floating structure of the present invention will be described based on a state in which it is floating on the water surface.

[0016] [Floating body] As described above, the float of the present invention comprises a float body and a float protruding portion provided so as to protrude downward from the lower portion of the float body. The float body and the float protruding portion usually have an internal space and are in communication with each other. This internal space has an airtight structure to prevent water from entering from the outside, and is configured to be able to accommodate various devices such as batteries for observation equipment, power generation equipment, and fuel containers, as well as weight adjustment members such as ballast and foam materials.

[0017] (Floating body) As described above, the float body is a hollow body having an internal space, and its upper surface appears above the water when floating on the water surface. For example, observation devices such as data recorders, communication devices, weather meters, and wind condition observation devices, as well as lighting, railings, etc. are mounted on the upper surface of the float body. The observation devices, etc. are protected by a container or cover as necessary.

[0018] The shape of the floating body is not particularly limited as long as it is a shape that can float on the water surface, but since it will be equipped with observation equipment, etc. as described above, it is preferable that the upper surface be a flat shape, such as a cylinder or a rectangular prism.

[0019] The material of the floating body is not particularly limited as long as it is waterproof (airtight), and examples thereof include steel, aluminum, FRP, polyethylene resin, PC concrete, polyvinyl chloride resin, and the like.

[0020] (floating body convex part) The float convex portion is a hollow body having an internal space, like the float body, and is provided so as to protrude downward from the bottom of the float body. Compared to conventional floats, the float of the present invention has a shape in which only a small part, such as the lower periphery of the float, is missing, so that a sufficient internal space can be secured, the float can float stably, and a large amount of equipment can be accommodated.

[0021] The shape of the float convex portion is not particularly limited as long as it fits within the float main body, and examples include a cylinder, a rectangular prism, an inverted truncated cone, an inverted truncated pyramid, a multi-stage cylinder, a multi-stage rectangular prism, a multi-stage inverted truncated cone, and a multi-stage inverted truncated pyramid.

[0022] The material of the floating body protrusion is not particularly limited as long as it is waterproof (airtight), and can be the same as that of the floating body main body.

[0023] [Sway control plate] The motion suppression plate is a member that is provided around the float convex portion and inward from the outer circumferential surface of the float main body, and suppresses motion caused by waves. The motion suppression plate provides resistance to the fluid flow at the bottom of the floating structure caused by vertical or horizontal motion caused by waves, thereby suppressing motion and enabling stable floating. "Inward from the outer circumferential surface of the float main body" means a range that does not exceed the outer circumferential surface of the float main body, and includes the same surface. By providing the motion suppression plate inward from the outer circumferential surface of the float main body, the floating structure can be made compact, and the risk of the motion suppression plate interfering with the outside can be reduced.

[0024] In addition, it is preferable that the motion suppression plate is provided above the bottom surface of the floating convex portion. In other words, it is preferable that the motion suppression plate does not protrude below the bottom surface of the floating convex portion. With such a configuration, the floating structure becomes more compact.

[0025] In addition, it is preferable that the motion suppression plate is provided continuously around the entire circumference of the float's convex portion, but it may also be provided intermittently or on specified sides (for example, only a pair of opposing sides when the float is a rectangular prism).

[0026] The material of the motion suppression plate is not particularly limited, and may be the same as that of the floating body.

[0027] Specific preferred embodiments of the motion suppression plate include a horizontal plate extending in the circumferential direction and provided outward with a gap from the lower side of the floating body's convex portion (see Fig. 1), and a vertical plate extending in the circumferential direction and provided downward with a gap from the outer bottom of the floating body's main body (see Fig. 4). Note that the horizontal plate or vertical plate in the present invention is a concept that includes a horizontal plate or a vertical plate inclined within 10°, preferably within 5°, from the horizontal or vertical direction.

[0028] In the case where the motion suppression plate is a horizontal plate extending in the circumferential direction and provided with a gap from the lower side of the floating convex portion outward, the gap between the floating convex portion and the motion suppression plate is, for example, about 20 to 200 mm, preferably 20 to 100 mm, more preferably 30 to 80 mm, and even more preferably 40 to 60 mm. In this case, when the floating structure is rocked, the water remaining around the floating convex portion flows out vigorously from the gap between the motion suppression plate and the floating convex portion, thereby increasing the damping force that reduces the vertical or horizontal rocking, and the rocking can be suppressed. In addition, the motion suppression plate is preferably disposed in a position flush with the bottom surface of the floating convex portion. This reduces the unevenness of the surface of the floating structure and prevents damage due to external interference.

[0029] In the case where the motion suppression plate is a vertical plate extending in the circumferential direction and provided with a gap downward from the outer bottom of the floating body, the distance from the floating body is, for example, about 20 to 200 mm, preferably 20 to 100 mm, more preferably 30 to 80 mm, and even more preferably 40 to 60 mm. In this case, as in the case where the horizontal plate is provided, the damping force that reduces pitching or rolling can be increased, and rocking can be suppressed. In addition, the motion suppression plate is preferably disposed in a position flush with the outer peripheral surface of the floating body. This reduces unevenness on the surface of the floating structure and prevents damage due to external interference.

[0030] When the floating structure of the present invention is cylindrical, the diameter of the floating body can be set appropriately depending on the application, for example, 0.3 to 100 m. In the case of an observation buoy, it is preferably 0.5 to 15 m, more preferably 1 to 10 m, and even more preferably 2 to 5 m. The diameter of the floating convex part is preferably 50 to 85% of the diameter of the floating body, more preferably 60 to 80%, and even more preferably 70 to 80%.

[0031] The draft of the float can be set appropriately depending on the application, etc., but is preferably 20 to 100% of the diameter of the float body, more preferably 20 to 70%, and even more preferably 30 to 50%. The height of the float convex portion is preferably 20 to 50% of the draft of the float, preferably 25 to 45%, and more preferably 30 to 40%.

[0032] In the case where the floating structure of the present invention is a rectangular parallelepiped, the size of the floating body and the floating convex portion can be set in the same manner, with the above-mentioned diameter being the length of the diagonal. Note that, in the case where the long side of the floating body is three times or more as long as the short side, since the swaying around the central axis in the short side direction is small, it is not necessarily necessary to provide a motion suppression plate at both ends in the longitudinal direction.

[0033] Hereinafter, one embodiment of the floating structure of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to this embodiment.

[0034] Here, FIG. 1 is a schematic side cross-sectional view of a floating body structure according to a first embodiment of the present invention. FIG. 2 is a schematic arrow cross-sectional view of the floating body structure according to the first embodiment of the present invention shown in FIG. 1 along the line A-A. FIG. 3 is an explanatory diagram showing a state in which the floating body structure according to the first embodiment of the present invention is floating on the sea, in which (a) shows a state of two-point mooring and (b) shows a state of one-point mooring. FIG. 4 is a schematic side cross-sectional view of a floating body structure according to a second embodiment of the present invention. FIG. 5 is a schematic end view of the line BB of the floating body structure according to the second embodiment shown in FIG. 4. It should be noted that the drawings referred to in the embodiments are schematic drawings for a deeper understanding. For example, the dimensional ratio of an object depicted in the drawing may differ from the dimensional ratio of an actual object. The white arrows in FIG. 1 and FIG. 4 represent the flow of water.

[0035] As shown in FIG. 1, a floating structure 10 according to a first embodiment of the present invention includes a floating body 12 and a motion suppression plate 14.

[0036] The float 12 comprises a float body 16, the upper surface of which appears above water, and a float protrusion 18 provided so as to protrude downward from the lower part of the float body 16.

[0037] The floating body main body 16 is a steel cylinder with a diameter of 2 m and a height of 0.9 m. A floating body protrusion 18 is provided at the bottom of the floating body main body 16. The floating body protrusion 18 is a steel cylinder with a diameter of 1.5 m and a height of 0.3 m. The floating body main body 16 and the floating body protrusion 18 are hollow and communicate with each other.

[0038] As shown in Fig. 2, the motion suppression plate 14 is a horizontal plate extending in the circumferential direction, provided around the floating body protrusion 18 and inward from the outer circumferential surface of the floating body main body 16, with a gap 20 of about 50 mm provided outward from the lower side of the floating body protrusion 18. The motion suppression plate 14 is connected to the outer circumferential surface of the floating body protrusion 18 and the bottom surface of the floating body main body 12 by brackets 22 provided at equal intervals in the circumferential direction of the floating body protrusion 18.

[0039] As shown in Fig. 3, the floating structure 10 according to the first embodiment of the present invention can be used, for example, as an observation buoy floating on the sea. The inside of the floating structure 10 (inside the floating body 16 and the floating protrusion 18) can accommodate ballast and batteries for observation equipment. In addition, a container 24 accommodating observation equipment is mounted on the upper part of the floating structure 10. In addition, when floating on the sea, a multi-point mooring method such as a two-point mooring method (Fig. 3(a)) in which the structure is moored by two mooring lines 28 connected to an anchor 26, or a single-point mooring method (Fig. 3(b)) in which the structure is moored by one mooring line 32 connected to an anchor 30 can be used.

[0040] Next, a floating structure according to a second embodiment of the present invention will be described in detail. As shown in FIG. 4, a floating structure according to the second embodiment of the present invention includes a floating body 12 and a motion suppression plate .

[0041] The float 12 has a similar configuration to that of the float of the floating structure according to the first embodiment described above, and therefore the same reference numerals are used and the description thereof will be omitted.

[0042] As shown in Fig. 5, the motion suppression plate 36 is a vertical plate extending in the circumferential direction, provided around the floating body protrusion 18 and inward from the outer circumferential surface of the floating body main body 16, with a gap 38 of about 50 mm downward from the outer bottom of the floating body main body 16. The motion suppression plate 36 is connected to the outer circumferential surface of the floating body protrusion 18 and the bottom surface of the floating body main body 16 by brackets 40 provided at equal intervals in the circumferential direction of the floating body protrusion 18.

[0043] Next, floating body structures according to the third and fourth embodiments of the present invention will be described. Note that the floating body structures according to the third and fourth embodiments have the same configuration as the floating body structure 10 described above, except for the floating body convex portion, and therefore the same reference numerals are used and the description is omitted. Also, the motion suppression plate is omitted for easier understanding. Here, FIG. 6 is a schematic side cross-sectional view of a float of the floating body structure according to the third embodiment of the present invention. FIG. 7 is a schematic side cross-sectional view of a float of the floating body structure according to the fourth embodiment of the present invention.

[0044] As shown in Fig. 6, in a floating body structure 42 according to a third embodiment of the present invention, a floating body protrusion 44 is configured as an inverted truncated cone having an inverted trapezoidal shape when viewed from the side. Also, as shown in Fig. 7, in a floating body structure 46 according to a fourth embodiment of the present invention, a floating body protrusion 48 is configured as a stepped two-stage cylinder when viewed from the side. EXAMPLES

[0045] [Swing characteristics test] Example 1 A rolling characteristic test was carried out using a floating structure according to the fifth embodiment of the present invention (Example 1). Fig. 8 is a photograph showing the floating body of the floating structure according to the fifth embodiment produced in Example. Fig. 9 is a photograph showing the floating structure according to the fifth embodiment produced in Example, where (a) is a photograph taken from diagonally above and (b) is a photograph taken from diagonally below. The floating structures used in this test (Examples 1 and 2, Comparative Example 1) were assumed to be 1 / 10 scale models of actual vessels.

[0046] Specifically, the float used was a cylindrical float body made of polyvinyl chloride resin with a diameter of 0.2 m and a height of 0.09 m, and a cylindrical float convex part made of polyvinyl chloride resin with a diameter of 0.15 m and a height of 0.03 m. The draft of the float was 0.08 m. The motion suppression plate was a horizontal plate made of polyvinyl chloride resin with a thickness of 5 mm, which extended in the circumferential direction and was installed around the convex part of the float and inside the outer circumferential surface of the float body, at a position where the bottom surface of the convex part of the float and the bottom surface of the motion suppression plate were flush with each other, with a gap of about 5 mm from the lower side of the convex part of the float outward. The outer circumferential surface of the horizontal plate was flush with the outer circumferential surface of the float body.

[0047] Example 2 A rolling characteristic test was carried out using a floating structure according to the sixth embodiment of the present invention (Example 2). Fig. 10 shows photographs of the floating structure according to the sixth embodiment produced in the example, where (a) shows a diagonally upward photograph and (b) shows a diagonally downward photograph.

[0048] Specifically, the float used was manufactured in the same manner as in Example 1. The motion suppression plate used was a circumferentially extending vertical plate made of polyvinyl chloride resin with a thickness of 5 mm, which was installed around the float's convex portion and inside the outer peripheral surface of the float's main body, at a position where the outer peripheral surface of the float's main body and the outer peripheral surface of the motion suppression plate were flush with each other, with a gap of about 5 mm below the outer bottom of the float's main body. The outer peripheral surface of the vertical plate was flush with the outer peripheral surface of the float's main body.

[0049] Comparative Example 1 A conventional floating structure (Comparative Example 1) was manufactured in which the float was a cylindrical body made of polyvinyl chloride resin with a diameter of 0.2 m and a height of 0.12 m. Figure 11 shows photographs of the conventional floating structure manufactured in the example, where (a) is a photograph taken obliquely from above and (b) is a photograph taken obliquely from below.

[0050] The vibration characteristic test was carried out under the following conditions. As shown in Figure 12, in a marine test tank with a length of 60 m, width of 4 m, and depth of 2.3 m, a motion sensor was attached to the top of the floating structure of this embodiment, and it was moored so as not to affect its motion. Waves were generated by a wave maker, and the pitch amplitude / wave amplitude (deg / m) of the floating structure in the wave period (sec) was measured. The results are shown in Figure 13.

[0051] As shown in FIG. 13, it was confirmed that the floating structures of the embodiments (Examples 1 and 2) have a smaller pitch amplitude / wave amplitude at peak time (3 s) than the conventional floating structure (Comparative Example 1), suppressing the rolling caused by waves and enabling stable floating. [Industrial Applicability]

[0052] INDUSTRIAL APPLICABILITY The floating structure of the present invention can be used as an observation buoy on the sea, and is therefore industrially useful. [Explanation of symbols]

[0053] 10 Floating Structures 12 Floating Body 14. Sway control plate 16 Floating body 18 Floating body protrusion 20 Gap 22 Bracket 24 Container 26 Anchor 28 Mooring line 30 Anchor 32 Mooring line 34 Floating Structures 36 Sway control plate 38 Gap 40 Bracket 42 Floating Structures 44 Floating body protrusion 46 Floating Structures 48 Floating body protrusion

Claims

1. A floating structure that floats on the water surface, A float including a float body whose upper surface appears above water and a float convex portion protruding downward from a lower portion of the float body; A motion suppression plate is provided around the floating protrusion and inward from the outer circumferential surface of the floating body to suppress motion caused by waves; Equipped with A floating structure, characterized in that the motion suppression plate is provided continuously around the entire circumference of the floating convex portion.

2. 2. The floating structure according to claim 1, wherein the motion suppression plate is a horizontal plate extending in the circumferential direction and provided outwardly from the lower side of the floating convex portion with a gap therebetween.

3. 2. The floating structure according to claim 1, wherein the motion suppression plate is a vertical plate extending in the circumferential direction and provided below the outer bottom of the floating body with a gap therebetween.

4. 4. The floating structure according to claim 2, wherein the motion suppression plate is provided above the bottom surface of the floating convex portion.

5. 5. The floating structure according to claim 1, wherein the floating body and the floating protrusion are each cylindrical.

6. 6. The floating structure according to claim 1, which is an observation buoy.

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