Hydrofoil module and watercraft

Abstract

To provide a hydrofoil module and a ship capable of reducing a load applied to a turning actuator for changing and holding an angle of attack of a hydrofoil part.SOLUTION: The hydrofoil module 103 includes the first rotation shaft 11 having the first rotation central axial line C1 extending in the left-right direction, and includes the clamp bracket 1, the swivel bracket 2 rotatably attached to the clamp bracket 1 via the first rotation shaft 11, the wing member 3 including the hydrofoil portion 31 and the strut portion 30, and the hydraulic cylinders 4 that rotate the wing member 3 back and forth around the first rotation central axial line C1 to change the angle of attack of the hydrofoil portion 31. A ship body 101 is raised by a pair of hydrofoil module parts 103a provided on both sides in the lateral direction of the ship body 101, and a first rotation shaft 11 is arranged in front of an area center 103a of a hydrofoil part 31 in a standard state S1 where attack angles of the hydrofoil parts 31 of the pair of hydrofoil module parts P1 are the same.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a hydrofoil module having a hydrofoil section and a vessel. [Background technology]

[0002] BACKGROUND ART Hydrofoil modules and ships equipped with hydrofoil sections are known in the art (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a vessel including a wing member including a hydrofoil strut and a hydrofoil section fixed to the lower end of the hydrofoil strut, an extendable actuator that changes the angle of attack of the hydrofoil section, and a hull. The actuator is configured to adjust the angle of attack of the hydrofoil section by extending and retracting to press against the wing member and rotate the hydrofoil section around a predetermined rotation center. A resultant force of lift and drag that raises the hull acts on the hydrofoil section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-207872 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not explicitly stated in Patent Document 1, when the hydrofoil section is raising the hull, a resultant force of lift and drag acts on the hydrofoil section, and this resultant force causes a moment about the center of rotation of the hydrofoil section to act on the wing member. Therefore, when maintaining the angle of attack of the hydrofoil section, it is necessary to maintain the position of the wing member by applying a pressing force to the wing member using an actuator to resist the moment acting on the hydrofoil section so that the wing member does not rotate. Therefore, a relatively large load is placed on the actuator for changing and maintaining the angle of attack of the hydrofoil section, and it is desirable to reduce the load on the actuator.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a hydrofoil module and a vessel that can reduce the load on a rotation actuator for changing and maintaining the angle of attack of the hydrofoil section. [Means for solving the problem]

[0007] In order to solve the above problem, a hydrofoil module according to a first aspect of the present invention comprises: a clamp bracket detachably attached to the hull, the clamp bracket including a first pivot shaft having a first pivot center axis extending in the left-right direction; a swivel bracket rotatably attached to the clamp bracket via the first pivot shaft; an underwater foil section to be placed underwater; a wing member including a columnar strut section having an underwater foil section at its lower end and an upper end attached to the swivel bracket; and a rotation actuator that rotates the wing member together with the swivel bracket back and forth around the first pivot center axis to change the angle of attack of the underwater foil section, wherein each of the hydrofoil module sections includes a clamp bracket, swivel bracket, wing member, and rotation actuator, and is configured to apply lift to the hull during navigation, causing the hull to rise, and in a standard state in which the angles of attack of the hydrofoil sections of the pair of hydrofoil module sections are the same, the first pivot shaft is positioned forward of the center of area of ​​the hydrofoil section. Here, the above-mentioned "area center of the hydrofoil portion" means the center of mass (center of gravity) of the hydrofoil portion in a plan view when the mass of the hydrofoil portion is uniformly distributed in the horizontal direction.

[0008] As described above, the hydrofoil module according to this first aspect includes a wing member including a hydrofoil section and a strut section, and a rotation actuator that changes the angle of attack of the hydrofoil section by rotating the wing member back and forth about the first rotation central axis. In a reference state in which the angles of attack of the hydrofoil sections of a pair of hydrofoil module sections on both sides of the hull in the transverse direction are the same, the first rotation shaft is located forward of the center of area of ​​the hydrofoil section. It is known that the center of lift, which is the point of application of lift on the hydrofoil section in the horizontal direction, is located forward of the center of area of ​​the hydrofoil section. Therefore, with the above configuration, by locating the first rotation shaft toward the lift center, which is forward of the center of area of ​​the hydrofoil section, in the reference state, the line of action of the resultant force of lift and drag on the hydrofoil section can be located relatively close to the first rotation shaft. This reduces the moment about the first rotation central axis generated by the resultant force of the hydrofoil section in the reference state. As a result, the load on the rotation actuator that changes and maintains the angle of attack of the hydrofoil section in the reference state can be reduced. Furthermore, in this first aspect, the hydrofoil module includes a clamp bracket detachably attached to the hull, and a swivel bracket rotatably attached to the clamp bracket via a first rotation shaft, and the wing member is attached to the swivel bracket. This allows the swivel bracket and wing member to be attached to the hull simply by attaching the clamp bracket to the hull, making it easy to attach the hydrofoil module to the hull.

[0009] In the hydrofoil module according to the first aspect, the first pivot shaft is preferably disposed forward of the center of area of ​​the hydrofoil section and rearward of the leading edge of the hydrofoil section in the reference state. Here, it is known that the center of lift, which is the point of application of lift on the hydrofoil section in the longitudinal direction, is located rearward of the leading edge of the hydrofoil section. Therefore, with the above configuration, in the reference state, the first pivot shaft can be disposed closer to the lift center, rearward of the leading edge of the hydrofoil section, and the line of action of the resultant force of lift and drag on the hydrofoil section can be positioned closer to the first pivot shaft. As a result, the load on the rotation actuator for changing and maintaining the angle of attack of the hydrofoil section can be further reduced in the reference state.

[0010] In the hydrofoil module according to the first aspect, the clamp bracket is preferably formed in the shape of a plate having bolt holes through which bolts for fixing the clamp bracket to the hull are passed, and is detachably fixed to the hull by the bolts passed through the bolt holes. With this configuration, the hydrofoil module can be more easily attached to the hull by the bolts passed through the bolt holes of the clamp bracket.

[0011] In the hydrofoil module according to the first aspect, the reference angle of attack, which is the angle of attack of the hydrofoil section in the standard state, is preferably set to a predetermined angle of 4 degrees or more and 8 degrees or less. By configuring the hydrofoil section in this manner, it is possible to generate an upward lift force that can stably raise the hull during navigation by setting the reference angle of attack of the hydrofoil section to 4 degrees or more and 8 degrees or less.

[0012] In this case, the initial angle of attack, which is the angle of attack of the hydrofoil section when the strut section extends vertically, is preferably greater than 0 degrees and less than the reference angle of attack. With this configuration, at a reference angle of attack greater than the initial angle of attack, the lower end of the strut section is positioned further forward than the upper end, so the inclination direction of the strut section can be made to follow the line of action of the drag and lift acting on the hydrofoil section. As a result, the resultant force of the drag and lift acting on the hydrofoil section can be applied along the longitudinal direction of the strut section, and the resultant force can be effectively transmitted to the hull.

[0013] In the hydrofoil module according to the first aspect, in the standard state, the strut sections are preferably inclined so that their lower ends are located further forward than their upper ends, and extend in a direction along the line of action of the resultant force of lift and drag acting on the hydrofoil sections. With this configuration, a resultant force for raising the hull that pushes up the strut sections can be generated along the direction in which the strut sections extend, and the hull can be effectively raised by the resultant force via the strut sections.

[0014] In the hydrofoil module according to the first aspect, the swivel bracket preferably includes a second pivot shaft having a second pivot central axis extending in the fore-and-aft direction, and rotatably supports the wing member via the second pivot shaft, and the wing member is configured to be able to rotate about the second pivot central axis to switch between an underwater position where the hydrofoil section is located underwater and an above-water position where the hydrofoil section is located above the water. With this configuration, the wing member can be switched between the underwater position and the above-water position without moving the hydrofoil section in the fore-and-aft direction, where it experiences relatively large resistance from the water.

[0015] In the hydrofoil module according to the first aspect, the rotation actuator is preferably a hydraulic cylinder that expands and contracts to press against the swivel bracket and rotate the swivel bracket about the first rotation axis, one end of the hydraulic cylinder being attached to the clamp bracket and the other end being attached to the swivel bracket. With this configuration, the swivel bracket can be easily rotated about the first rotation axis relative to the clamp bracket by the hydraulic cylinder. Furthermore, since the hydraulic cylinder is attached to the clamp bracket and the swivel bracket, installation of the hydraulic cylinder to the hull can be completed simply by attaching the clamp bracket to the hull.

[0016] In this case, preferably, the hydraulic oil supply device includes a pump unit that supplies hydraulic oil to the hydraulic cylinder and a motor unit that drives the pump unit, and is attached to the clamp bracket. With this configuration, the hydraulic cylinder can be easily driven by the motor unit that drives the pump unit. Furthermore, because the hydraulic oil supply device is attached to the clamp bracket, attachment of the hydraulic oil supply device to the hull can be completed simply by attaching the clamp bracket to the hull.

[0017] In the configuration including the hydraulic oil supply device including the pump unit and the motor unit, the hydraulic cylinder and the hydraulic oil supply device are preferably arranged side by side in the left-right direction and are arranged rearward of the first rotating shaft. This configuration allows the hydraulic cylinder and the hydraulic oil supply device to be arranged side by side in the left-right direction, thereby reducing the size of the device in the front-to-rear direction. Furthermore, the angle of attack can be changed by the hydraulic cylinder pressing the first rotating shaft from the rear.

[0018] In the above-described configuration in which the hydraulic cylinder and the hydraulic oil supply device are arranged side by side and rearward of the first pivot shaft, preferably, the other end of the hydraulic cylinder is arranged forward of one end of the hydraulic cylinder and above the first pivot shaft, and the hydraulic cylinder is configured to extend the rod to rotate the wing member rearward to decrease the angle of attack, and to retract the rod to rotate the wing member forward to increase the angle of attack. With this configuration, the other end of the hydraulic cylinder can be arranged above the first pivot shaft, thereby reducing the horizontal size of the device.

[0019] In the hydrofoil module according to the first aspect, in the reference state, the first pivot shaft is preferably arranged on the line of action of the resultant force of lift and drag acting on the hydrofoil section when viewed from the left and right. With this configuration, in the reference state, the line of action of the resultant force can be arranged closer to the first pivot central axis, and therefore, in the reference state, the moment about the first pivot central axis generated by the resultant force of the hydrofoil section can be made extremely small.

[0020] In the hydrofoil module according to the first aspect, in the reference state, the first rotation central axis of the first rotation shaft is preferably located forward of the line of action of the resultant force of lift and drag acting on the hydrofoil section. With this configuration, if the angle of attack of the wing member can no longer be maintained by the rotation actuator due to, for example, large resistance acting on the hydrofoil section from the water, the wing member can be rotated rearward, where the angle of attack becomes smaller, thereby preventing the wing member from rotating forward and thereby reducing the stability of the hull.

[0021] In order to solve the above-mentioned problems, a watercraft according to a second aspect of the present invention comprises a hull and a hydrofoil module mounted on the hull, the hydrofoil module having a first rotation shaft with a first rotation center axis extending in the left-right direction, the hydrofoil module comprising a clamp bracket detachably mounted on the hull, a swivel bracket rotatably mounted to the clamp bracket via the first rotation shaft, a hydrofoil section to be placed underwater, and a wing section having a columnar strut section at the lower end of which the hydrofoil section is mounted and the upper end of which is attached to the swivel bracket. and a rotation actuator that rotates the wing member together with the swivel bracket back and forth around the first rotation center axis to change the angle of attack of the underwater wing section, each of which includes a clamp bracket, a swivel bracket, a wing member, and a rotation actuator, and is configured so that a pair of hydrofoil module sections are provided on both sides of the hull in the left-right direction to provide lift to the hull during navigation, causing the hull to rise, and in a standard state where the angles of attack of the hydrofoil sections of the pair of hydrofoil module sections are the same, the first rotation axis is positioned forward of the center of area of ​​the hydrofoil section.

[0022] The watercraft according to the second aspect includes, as described above, a wing member including a hydrofoil section and a strut section, and a rotation actuator that rotates the wing member back and forth about a first rotation axis to change the angle of attack of the hydrofoil section. In a reference state in which the angles of attack of the hydrofoil sections of a pair of hydrofoil module sections on both sides of the hull in the transverse direction are the same, the first rotation axis is located forward of the center of area of ​​the hydrofoil section. It is known that the center of lift, which is the point of action of lift acting on the hydrofoil section in the horizontal direction, is located forward of the center of area of ​​the hydrofoil section. Therefore, with the above configuration, by locating the first rotation axis toward the lift center, which is forward of the center of area of ​​the hydrofoil section, in the reference state, the line of action of the resultant force of lift and drag of the hydrofoil section can be located relatively close to the first rotation axis. This reduces the moment about the first rotation axis generated by the resultant force of the hydrofoil section in the reference state. As a result, a watercraft can be provided that can reduce the load on the rotation actuator that changes and maintains the angle of attack of the hydrofoil section in the reference state. Furthermore, in this second aspect, the hydrofoil module includes a clamp bracket detachably attached to the hull, and a swivel bracket rotatably attached to the clamp bracket via a first rotation shaft, and the wing member is attached to the swivel bracket. This allows the swivel bracket and wing member to be attached to the hull simply by attaching the clamp bracket to the hull, making it easy to attach the hydrofoil module to the hull.

[0023] In the watercraft according to the second aspect, the first pivot shaft is preferably disposed forward of the center of area of ​​the hydrofoil section and rearward of the leading edge of the hydrofoil section in the reference state. Here, it is known that the center of lift, which is the point of application of lift on the hydrofoil section in the longitudinal direction, is located rearward of the leading edge of the hydrofoil section. Therefore, with the above configuration, in the reference state, the first pivot shaft can be disposed closer to the lift center, which is rearward of the leading edge of the hydrofoil section, and the line of action of the resultant force of the lift and drag of the hydrofoil section can be positioned closer to the first pivot shaft. As a result, the load on the rotation actuator for changing and maintaining the angle of attack of the hydrofoil section can be further reduced in the reference state.

[0024] In the watercraft according to the second aspect, the clamp bracket is preferably formed in the shape of a plate having bolt holes through which bolts for fixing the clamp bracket to the hull are passed, and is detachably fixed to the hull by the bolts passed through the bolt holes. With this configuration, the hydrofoil module can be more easily attached to the hull by the bolts passed through the bolt holes of the clamp bracket.

[0025] In the watercraft according to the second aspect, the reference angle of attack, which is the angle of attack of the hydrofoil section in a standard state, is preferably set to a predetermined angle of 4 degrees or more and 8 degrees or less. By configuring the hydrofoil section in this manner, it is possible to generate an upward lift force that can stably raise the hull during navigation by setting the reference angle of attack of the hydrofoil section to 4 degrees or more and 8 degrees or less.

[0026] In this case, the initial angle of attack, which is the angle of attack of the hydrofoil section when the strut section extends vertically, is preferably greater than 0 degrees and less than the reference angle of attack. With this configuration, at a reference angle of attack greater than the initial angle of attack, the lower end of the strut section is positioned further forward than the upper end, so the inclination direction of the strut section can be made to follow the line of action of the resultant force of drag and lift acting on the hydrofoil section. As a result, the resultant force of drag and lift acting on the hydrofoil section can be applied along the longitudinal direction of the strut section, and the resultant force can be effectively transmitted to the hull.

[0027] In the watercraft according to the second aspect, in the standard state, the strut sections are preferably inclined so that their lower ends are positioned further forward than their upper ends, and extend in a direction along the line of action of the resultant force of lift and drag acting on the hydrofoil section. With this configuration, a resultant force for raising the hull that pushes up the strut sections can be generated in the direction in which the strut sections extend, and the hull can be effectively raised by this resultant force via the strut sections.

[0028] In the watercraft according to the second aspect, the swivel bracket preferably includes a second pivot shaft having a second pivot central axis extending in the fore-and-aft direction, and rotatably supports the wing member via the second pivot shaft, and the wing member is configured to rotate about the second pivot central axis to switch between an underwater position where the hydrofoil section is located underwater and an above-water position where the hydrofoil section is located above the water. With this configuration, the wing member can be switched between the underwater position and the above-water position without moving the hydrofoil section in the fore-and-aft direction, where it experiences relatively large resistance from the water. [Effects of the Invention]

[0029] According to the present invention, as described above, it is possible to reduce the load on the rotation actuator for changing and maintaining the angle of attack of the hydrofoil section. [Brief explanation of the drawings]

[0030] [Figure 1]1 is a perspective view showing the overall configuration of a vessel equipped with a hydrofoil module according to an embodiment. [Figure 2] 1 is a plan view showing the overall configuration of a vessel equipped with a hydrofoil module according to an embodiment. [Figure 3] FIG. 3 is an enlarged view of the hydrofoil module portion on the right side of FIG. 2. [Figure 4] FIG. 2 is a perspective view from the rear side showing the overall configuration of the right hydrofoil module section according to the embodiment. [Figure 5] FIG. 2 is a perspective view from the front showing the upper portion of the right hydrofoil module section according to the embodiment. [Figure 6] 10 is a schematic side view for explaining the operation of the hydraulic cylinder when a foreign object such as driftwood collides with a wing member of the hydrofoil module section according to the embodiment. FIG. [Figure 7] 1 is a schematic side view showing a hydrofoil module portion of the embodiment in a reference state of the hydrofoil portion of the embodiment. FIG. [Figure 8] 1 is a schematic side view showing the hydrofoil section of the hydrofoil module section in an initial state according to an embodiment. FIG. [Figure 9] 10 is a plan view for explaining the center of area and center of lift of the hydrofoil portion of the wing member of the hydrofoil module portion according to the embodiment. FIG. [Figure 10] 10A and 10B are diagrams for explaining a rotating section that rotates the wing members of the hydrofoil module section according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, an embodiment will be described with reference to the drawings.

[0032] [Embodiment] (Overall configuration of the ship) The configuration of a vessel 100 equipped with a hydrofoil module 103 according to an embodiment will be described with reference to FIGS.

[0033] The X direction in the drawing indicates the fore-and-aft direction based on the hull 101. The X1 and X2 directions indicate the front and rear, respectively. The Y direction in the drawing indicates the left-right direction (width direction of the hull 101) based on the hull 101. The Y1 and Y2 directions indicate the starboard and port directions, respectively. The Z direction in the drawing indicates the vertical direction. The Z1 and Z2 directions indicate the upward and downward directions, respectively.

[0034] The Y direction is also the direction in which the first rotation center axis C1, which is the rotation center of the swivel bracket 2, extends. The swivel bracket 2 rotates around the first rotation center axis C1 together with the wing member 3. At this time, the swivel bracket 2 rotates relative to the clamp bracket 1. The X direction is also the direction in which the second rotation center axis C2, which is the rotation center of the wing member 3, extends. The wing member 3 rotates around the second rotation center axis C2. At this time, the wing member 3 rotates relative to the swivel bracket 2 and the clamp bracket 1. In a plan view, the first rotation center axis C1 and the second rotation center axis C2 are perpendicular to each other.

[0035] The rotation direction of the swivel bracket 2 and the wing member 3 around the first rotation central axis C1 in the figure is indicated by the r direction. The rotation direction of the wing member 3 around the second rotation central axis C2 in the figure is indicated by the R direction. When not in use, the wing member 3 is rotated in the R direction to move from an underwater position to an abovewater position.

[0036] As shown in FIGS. 1 and 2, the watercraft 100 includes a hull 101, an outboard motor 102, and a hydrofoil module 103 provided on the hull 101.

[0037] The vessel 100 is a monohull vessel. The vessel 100 is a so-called hydrofoil vessel that sails at high speed by raising the hull 101 above the water surface using lift F1 (see FIG. 7 ) obtained from hydrofoil modules 103. The hydrofoil modules 103 are configured to provide lift F1 to the hull 101 during sailing, causing the hull 101 to rise, using a pair of hydrofoil module sections 103a provided on both lateral sides of the hull 101. This lift F1 is obtained from the hydrofoil sections 31, which have an angle of attack. The vessel 100 reduces the resistance that the hull 101 receives from water during sailing by raising the hull 101 using the pair of hydrofoil module sections 103a. Each hydrofoil module section 103a includes identical components, such as a clamp bracket 1, a swivel bracket 2, a wing member 3, and a hydraulic cylinder 4. The hydraulic cylinder 4 is an example of a "rotation actuator" in the claims.

[0038] An outboard motor 102 is mounted on the stern of the hull 101. The hydrofoil module 103 is arranged near the midpoint between the bow and stern of the hull 101 in the fore-and-aft direction. The vessel 100 is equipped with not only the hydrofoil module 103 but also a rear hydrofoil (not shown) provided near the stern of the hull 101 as a hydrofoil. One rear hydrofoil is arranged on the center line C (see Figure 2) in the transverse direction of the hull 101. The hydrofoil section 31 of the hydrofoil module 103 and the hydrofoil section of the rear hydrofoil are both arranged below the side of the hull 101.

[0039] (Hull configuration) A steering unit 104 protruding upward from the deck 101a is provided in the center of the hull 101. The steering unit 104 has a windshield 104a on the front side, a steering wheel (not shown), and the like.

[0040] As shown in FIG. 1, rope holding members T1 that hook and hold one end of a rope T are provided on both lateral sides of the steering unit 104. As an example, the rope holding members T1 are configured with U-shaped hooks. The other end of the rope T is connected to a rope holding member T2 of the wing member 3 of the hydrofoil module 103. The rope T is used to manually pull up the wing member 3 (hydrofoil section 31) when switching it from the underwater position to the above-water position. The rope T is also used to maintain the above-water position of the wing member 3. Note that, to make the drawings easier to understand, the rope T is shown only in FIG. 1 and is omitted from the other drawings.

[0041] (Hydrofoil module configuration) The pair of hydrofoil module sections 103a (hydrofoil modules 103) are configured symmetrically with respect to a center line C (see FIG. 2) in the left-right direction of the hull 101. The ship 100 is equipped with an angle-of-attack control section 9 (see FIG. 2) on the hull 101. The angle-of-attack control section 9 is configured to adjust the angle of attack of the hydrofoil section 31 by controlling the drive of a hydraulic cylinder 4 (described later) for rotating the wing member 3 (hydrofoil section 31).

[0042] When the left and right balance of the hull 101 is maintained, that is, when no external forces such as wind and waves that disrupt the left and right balance of the hull 101 are acting on the hull 101, the hydrofoil module 103 is in a reference state S1 (see FIG. 7) in which the angles of attack of the hydrofoil sections 31 of the pair of hydrofoil module sections 103a are the same. The angle of attack of the hydrofoil sections 31 in the reference state S1 is called the reference angle of attack A1 (see FIG. 7). As an example, the reference angle of attack A1, which is the angle of attack of the hydrofoil sections 31 in the reference state S1, is set to a predetermined angle of 4 degrees or more and 8 degrees or less. As a specific example, the reference angle of attack A1 is set to 6 degrees.

[0043] When an external force that disrupts the lateral balance of the hull 101 acts on the hull 101, the angle of attack of the right and left hydrofoil module sections 103a and 103a is controlled by the angle-of-attack control section 9 so that the angles of attack of the right and left hydrofoil module sections 103a vary by equal angular amounts in opposite directions around the reference angle of attack A1 (see FIG. 7). This stabilizes the hull 101 in a raised state due to the hydrofoil modules 103. In other words, when an external force that disrupts the lateral balance of the hull 101 acts on the hull 101, the angle of attack of the right hydrofoil module section 103a varies by an angular amount of +α degrees from the reference angle of attack A1, and the angle of attack of the left hydrofoil module section 103a varies by an angular amount of -α degrees from the reference angle of attack A1.

[0044] As described above, the pair of hydrofoil module sections 103a are configured symmetrically with respect to the center line C (see Figure 2) in the left-right direction of the hull 101, so below we will explain the hydrofoil module section 103a on the right side (Y1 direction side), and omit the explanation of the hydrofoil module section 103a on the left side (Y2 direction side).

[0045] As shown in Figures 3 to 5, the right hydrofoil module section 103a (hydrofoil module 103) includes a clamp bracket 1, a swivel bracket 2, a wing member 3, a hydraulic cylinder 4, and a hydraulic oil supply device 5. Note that the hull 101 is not shown in Figures 3 and onwards.

[0046] (Configuration of clamp bracket for hydrofoil module) The clamp bracket 1 shown in Figures 3 to 5 is configured to be detachably attached to a hull 101 (see Figure 1). More specifically, the clamp bracket 1 is formed in the shape of a plate having bolt holes 10 through which bolts B pass to secure the clamp bracket 1 to the hull 101. Multiple bolt holes 10 in the clamp bracket 1 are provided spaced apart horizontally. The thickness direction of the plate-shaped clamp bracket 1 is the up-down direction. The clamp bracket 1 is detachably fixed to a gantry 101b (see Figure 1) of the hull 101 by bolts B passed through the bolt holes 10. The clamp bracket 1 is fixed directly to the gantry 101b from above by the bolts B. The gantry 101b has multiple female threads (not shown) arranged in a row at the front and rear for threading the bolts B, allowing the fore-aft position of the clamp bracket 1 relative to the hull 101 to be adjusted.

[0047] The clamp bracket may not be fixed directly to the gantry, but may be fixed indirectly to the gantry via a dedicated mounting plate, etc. In this case, the mounting plate may be configured with a plurality of bolt holes arranged in the front and rear, so that the mounting position of the clamp bracket relative to the mounting plate (hull) can be changed.

[0048] The clamp bracket 1 is a base member for fixing each part of the hydrofoil module 103 to the hull 101. In other words, the swivel bracket 2, wing member 3, hydraulic cylinder 4, and hydraulic oil supply device 5 are attached directly or indirectly to the clamp bracket 1, and are attached to the hull 101 via the clamp bracket 1. Therefore, when the clamp bracket 1 is attached to the hull 101, the attachment of the swivel bracket 2, wing member 3, hydraulic cylinder 4, and hydraulic oil supply device 5 to the hull 101 is also complete.

[0049] The clamp bracket 1 includes a first rotation shaft 11 and a cylinder support portion 12 .

[0050] The first rotating shaft 11 is disposed on the front side of the clamp bracket 1. The first rotating shaft 11 has a first rotating center axis C1 extending in the left-right direction. The swivel bracket 2 is attached to the first rotating shaft 11 so that it can rotate in the R direction. An angle sensor 9a (see Figure 3) is provided at the left end of the first rotating shaft 11. The angle sensor 9a is configured to detect the rotation angle of the swivel bracket 2 relative to the clamp bracket 1 (the angle of attack of the hydrofoil section 31). The angle-of-attack control section 9 (see Figure 2) is configured to adjust the angle of attack of the hydrofoil section 31 based on the measurement value of the angle sensor 9a.

[0051] The hydraulic cylinder 4 extends in the front-to-rear direction in a plan view. One end 40a of the hydraulic cylinder 4 is attached to the cylinder support portion 12 of the clamp bracket 1. The cylinder support portion 12 of the clamp bracket 1 is configured as a rotation shaft having a rotation center axis C3 extending in the left-to-right direction. The rotation center axis C3 is an axis line parallel to the first rotation center axis C1. The hydraulic cylinder 4 is rotatably attached to the clamp bracket 1 via the cylinder support portion 12.

[0052] As shown in Fig. 5, a buffer member 13 is provided on the upper surface of the front end portion of the clamp bracket 1. The buffer member 13 is disposed in front of the first rotating shaft 11. As shown in Fig. 6, the hydraulic cylinder 4 has a front oil chamber 401, a rear oil chamber 402, and a piston 403 that separates the oil chambers 401 and 402. The piston 403 is provided with an oil passage 403a that connects the oil chambers 401 and 402, and a valve 403b that normally blocks the oil passage 403a and maintains the valve 403b in a closed state. The valve 403b is configured as a relief valve that switches to an open state when a load (pressure) equal to or greater than a predetermined value is applied from the oil chamber 401. The piston 403 is fixed to the rod 41.

[0053] Here, if a foreign object K such as driftwood collides with the wing member 3 during navigation and a large force acts to push the wing member 3 backward, a large force acts on the hydraulic cylinder 4 via the wing member 3 and the swivel bracket 2 in a direction that extends the rod 41 (a force that moves the rod 41 in the direction of the white arrow pointing forward). As a result, the piston 403 increases the pressure in the oil chamber 401, and when the valve 403b receives a load (pressure) from the oil chamber 401 that is equal to or greater than a predetermined value, it switches to an open state. Then, the oil chamber 401 and the oil chamber 402 communicate with each other via the oil passage 403a, and the state in which the hydraulic cylinder 4 holds the rotation position of the wing member 3 in the r direction is released. As a result, the wing member 3 rotates largely backward together with the swivel bracket 2 about the first rotation center axis C1, so as to jump up. In this way, the hydrofoil module 103 can deflect (pass) foreign objects K such as driftwood backward. The buffer member 13 is configured to come into contact with the swivel bracket 2 to prevent the swivel bracket 2 from directly colliding with the clamp bracket 1 when the wing member 3 together with the swivel bracket 2 rotates significantly rearward around the first rotation center axis C1 due to a collision with a foreign object K such as driftwood.

[0054] The buffer member 13 is made of an elastic material. As one example, the buffer member 13 is made of a block-shaped rubber material. Alternatively, the buffer member may be made of a spring material or the like. The elastic buffer member 13 causes the swivel bracket 2 to indirectly contact the clamp bracket 1, so that the impact when the swivel bracket 2 contacts the clamp bracket 1 is absorbed and reduced.

[0055] (Configuration of swivel bracket of hydrofoil module) The swivel bracket 2 shown in Figures 3 to 5 is rotatably attached to the clamp bracket 1 via a first rotation shaft 11. The swivel bracket 2 is a member for indirectly attaching the wing member 3 attached to the swivel bracket 2 to the clamp bracket 1. The swivel bracket 2 is attached to the clamp bracket 1 from above.

[0056] The swivel bracket 2 integrally includes an upper portion 20 disposed above the clamp bracket 1 and a side portion 21 disposed laterally (to the right) of the clamp bracket 1. The side portion 21 has a main wall portion 21a, a front wall portion 21b, and a rear wall portion 21c. The main wall portion 21a is connected at its upper end to the upper portion 20 and extends in a direction perpendicular to the left-right direction (front-to-back and up-to-down directions). The front wall portion 21b protrudes from the front end of the main wall portion 21a to the right, i.e., away from the hull 101. The rear wall portion 21c protrudes from the rear end of the main wall portion 21a to the right, i.e., away from the hull 101. The front wall portion 21b and the rear wall portion 21c form a pair facing each other in the front-to-back direction. The strut portion 30 of the wing member 3 disposed in the underwater position is disposed along the main wall portion 21a.

[0057] The swivel bracket 2 includes a cylinder support portion 22 provided on the upper portion 20 and a second rotation shaft 23 provided on the side portion 21 .

[0058] The other end 41a of the hydraulic cylinder 4 is attached to the cylinder support portion 22 of the swivel bracket 2. The other end 41a is located forward of the one end 40a and above the first rotation shaft 11. The cylinder support portion 22 of the swivel bracket 2 is configured as a rotation shaft having a rotation center axis C4 extending in the left-right direction. The rotation center axis C4 is an axis line parallel to the first rotation center axis C1. The hydraulic cylinder 4 is rotatably attached to the swivel bracket 2 via the cylinder support portion 22. Unlike the cylinder support portion 12, which is fixed in position, the cylinder support portion 22 of the swivel bracket 2 moves along an arc-shaped path extending in the r direction above the first rotation shaft 11 when the swivel bracket 2 and the wing member 3 rotate in the r direction about the first rotation center axis C1.

[0059] The second rotating shaft 23 has a second rotating center axis C2 extending in the front-rear direction. The second rotating shaft 23 is disposed between the front wall portion 21b and the rear wall portion 21c. The wing member 3 is attached to the second rotating shaft 23 in a state where it can rotate in the R direction. That is, the swivel bracket 2 rotatably supports the wing member 3 via the second rotating shaft 23.

[0060] (Configuration of wing members of hydrofoil module) The wing member 3 shown in FIGS. 3 and 4 includes a columnar (plate-shaped) strut portion 30 and a hydrofoil portion 31.

[0061] The strut section 30 has a hydrofoil section 31 attached to its lower end 30a. The upper end 30b of the strut section 30 is attached to the second rotation shaft 23 of the swivel bracket 2. Note that the above-mentioned "lower end 30a" and "upper end 30b" refer to the lower end 30a and upper end 30b of the strut section 30 when the hydrofoil section 31 is in its underwater position.

[0062] When the hydrofoil section 31 is in its underwater position, the strut section 30 extends in the vertical direction. When viewed from the left and right, the strut section 30 is formed in a rectangular shape with its longer sides extending in the vertical direction and its shorter sides extending in the front-to-rear direction. A bullet-shaped central section 32 extending in the front-to-rear direction is provided at the lower end 30a of the strut section 30. The front portion of the central section 32 is rounded, and the rear portion protrudes rearward in a tapered shape.

[0063] The hydrofoil section 31 is configured to be placed underwater. The hydrofoil section 31 is configured as a pair provided on both left and right sides of the central section 32. That is, the pair of hydrofoil sections 31 are connected to both left and right sides of the central section 32. The hydrofoil section 31 extends in the left and right direction, and is a wing whose thickness direction is in the up and down direction. In the left and right direction, the hydrofoil section 31 is formed in a shape such that the leading edge 31a gradually approaches the trailing edge 31b with increasing distance from the central section 32. That is, in the left and right direction, the hydrofoil section 31 decreases in size in the front-to-rear direction with increasing distance from the central section 32. The hydrofoil section 31 has a streamlined shape in longitudinal cross section (a cross section taken along a plane perpendicular to the left and right direction). That is, the hydrofoil section 31 is formed so that it is thicker on the front side and gradually becomes thinner toward the rear. In a longitudinal cross section, the front portion of the hydrofoil portion 31 including the leading edge 31a is rounded, and the rear portion of the hydrofoil portion 31 including the trailing edge 31b protrudes rearward in a tapered shape.

[0064] The initial angle of attack A2 (see FIG. 8), which is the angle of attack of the hydrofoil section 31 when the strut section 30 extends vertically (initial state), is greater than 0 degrees and less than the reference angle of attack A1 (see FIG. 7). Preferably, the initial angle of attack A2 is greater than or equal to 1 degree and less than or equal to 5 degrees. As a specific example, the initial angle of attack A2 is 3 degrees.

[0065] The wing member 3 is configured to rotate about the second rotation center axis C2, so as to be switchable between an underwater position where the hydrofoil section 31 is positioned underwater, and an above-water position where the hydrofoil section 31 is positioned above the water. This switching is achieved by using a rope T (see FIG. 1), one end of which is held by a rope holding member T1. The strut section 30 is provided with a rope holding member T2 that hooks onto and holds the other end of the rope T. The strut section 30 is also provided with a rope passing member T3 that passes the rope T between the rope holding member T1 and the rope holding member T2. In the vertical direction, the rope passing member T3 is disposed below the second rotation shaft 23 and above the rope holding member T2.

[0066] When the hydrofoil section 31 is in its underwater position, the rope holding member T2 is configured as a U-shaped hook that protrudes to the right (away from the hull 101) from the strut section 30. When the hydrofoil section 31 is in its underwater position, the rope route member T3 includes a rope abutment portion T30 that abuts against the rope T, and a holding portion T31 that holds the rope abutment portion T30 at its right end. The holding portion T31 is a U-shaped portion that protrudes to the right (away from the hull 101) from the strut section 30, and protrudes further to the right than the rope holding member T2. Therefore, the rope abutment portion T30 is positioned a predetermined distance to the right (away from the hull 101) from the strut section 30 (second pivot shaft 23).

[0067] This rope relay member T3 positions the rope T (see FIG. 1) at a position away from the second pivot shaft 23. Therefore, when a person pulls the rope T to switch the hydrofoil section 31 from the underwater position to the above-water position, a relatively large moment can be generated around the second pivot central axis C2 of the second pivot shaft 23 on the wing member 3, including the strut section 30 and the hydrofoil section 31. In other words, the rope relay member T3 allows the user to easily switch the hydrofoil section 31 from the underwater position to the above-water position. Although not shown, when the hydrofoil section 31 is in the above-water position, the wing member 3 is held in a state in which the hydrofoil section 31 is positioned directly above the strut section 30 and the strut section 30 extends in the vertical direction. The forces acting on the hydrofoil section 31 from the water during sailing will be described later.

[0068] (Configuration of hydraulic cylinder 4 and hydraulic oil supply device of hydrofoil module) 3 and 4 is configured to rotate the wing member 3 together with the swivel bracket 2 back and forth (in the r direction) around the first rotation central axis C1 to change the angle of attack of the hydrofoil section 31. The hydraulic cylinder 4 is configured to press the swivel bracket 2 by expanding and contracting, causing the swivel bracket 2 to rotate around the first rotation central axis C1.

[0069] The hydraulic cylinder 4 includes a cylindrical cylinder body 40 and a rod 41 that moves back and forth from the cylinder body 40 .

[0070] One end 40a (cylinder body 40) of the hydraulic cylinder 4 is attached to the clamp bracket 1. More specifically, the one end 40a is rotatably supported by the cylinder support portion 12 of the clamp bracket 1. The other end 41a (rod 41) of the hydraulic cylinder 4 is attached to the swivel bracket 2. More specifically, the other end 41a is rotatably supported by the cylinder support portion 22 of the swivel bracket 2. The hydraulic cylinder 4 is disposed behind the first rotation shaft 11 of the clamp bracket 1.

[0071] The other end 41a of the hydraulic cylinder 4 is disposed forward of the one end 40a of the hydraulic cylinder 4 and above the first pivot shaft 11. The hydrofoil section 31, which determines the angle of attack, is disposed below the first pivot shaft 11 of the clamp bracket 1. The hydraulic cylinder 4 is configured to extend the rod 41 to rotate the wing member 3 backward (one side of the r direction) to decrease the angle of attack. The hydraulic cylinder 4 is configured to retract the rod 41 to rotate the wing member 3 forward (the other side of the r direction) to increase the angle of attack. Therefore, for example, to change the initial angle of attack A2 to a reference angle of attack A1 that is greater than the initial angle of attack A2, the hydraulic cylinder 4 retracts the rod 41 to rotate the wing member 3 forward (the other side of the r direction).

[0072] The hydraulic oil supply device 5 is attached to the clamp bracket 1. The hydraulic oil supply device 5 is disposed behind the first rotation shaft 11 of the clamp bracket 1. The hydraulic oil supply device 5 and the hydraulic cylinder 4 are disposed side by side in the left-right direction. The hydraulic cylinder 4 is disposed to the left of the hydraulic oil supply device 5.

[0073] The hydraulic oil supply device 5 includes a pump unit 50 that supplies hydraulic oil to the hydraulic cylinder 4, and a motor unit 51 that drives the pump unit 50. The pump unit 50 is connected to two oil chambers 401 and 402 (see FIG. 6) of the hydraulic cylinder 4 by two hoses 52 that carry hydraulic oil.

[0074] (force acting on the hydrofoil from water during sailing) With reference to Figure 7, the forces acting from the water on the hydrofoil section 31 when the vessel 100 (see Figure 1) is sailing forward will be described. The forces acting from the water on the hydrofoil section 31 when sailing include an upward lift force F1 and a backward drag force F2. The lift force F1 and the drag force F2 act in directions perpendicular to each other. The lift force F1 and the drag force F2 vary by adjusting the angle of attack of the hydrofoil section 31. The resultant force F3 of the lift force F1 and the drag force F2 always acts in an upward and backward direction.

[0075] 7 and 9, in a reference state S1 in which the angles of attack of the hydrofoil sections 31 of a pair of hydrofoil module sections 103a are the same, the first rotating shaft 11 is disposed forward of the center of area P1 of the hydrofoil section 31. Furthermore, in the reference state S1, the first rotating shaft 11 is disposed forward of the center of area P1 of the hydrofoil section 31 and rearward of the leading edge 31a of the hydrofoil section 31. Here, the above-mentioned "center of area P1 of the hydrofoil section 31" refers to the center of mass (center of gravity) of the hydrofoil section 31 in a plan view when the mass of the hydrofoil section 31 is uniformly distributed in the horizontal direction.

[0076] Here, in the horizontal direction, the lift center P2, which is the point of action at which the lift F1 acts on the hydrofoil section 31, is located forward of the center of area P1 of the hydrofoil section 31. This is a well-known finding in the field of lift. Furthermore, in the longitudinal direction, the lift center P2, which is the point of action at which the lift F1 acts on the hydrofoil section 31, is located rearward of the leading edge 31a of the hydrofoil section 31. This is also a well-known finding in the field of lift. Furthermore, the drag F2 is a smaller force than the lift F1. Note that the lift center P2 is located at a distance of approximately 25% from the leading edge 31a, assuming that the distance from the leading edge 31a to the trailing edge 31b is 100%. In Figure 7, the position at a distance of approximately 25% from the leading edge 31a is indicated by line L1.

[0077] Therefore, in the reference state S1, the first rotating shaft 11 is disposed relatively close to the center of lift P2 in the longitudinal direction. This "relatively close" concept encompasses both the first rotating shaft 11 being disposed at the same position as the center of lift P2 in the longitudinal direction and the first rotating shaft 11 being disposed at a position slightly offset from the center of lift P2.

[0078] In the reference state S1, the strut section 30 is inclined so that the lower end 30a is positioned further forward than the upper end 30b, and extends in a direction along the line of action L of the resultant force F3 of the lift force F1 and the drag force F2 acting on the hydrofoil section 31. More preferably, in the reference state S1, the line of action L of the resultant force F3 is parallel to the center line of the strut section 30 in the short direction (front-to-rear direction). In short, in the reference state S1, the hydrofoil section 31 is configured to raise the hull 101 by generating the resultant force F3 that pushes up the strut section 30 along the longitudinal direction of the strut section 30 so as not to generate a large moment in the wing member 3.

[0079] In the reference state S1, the first rotating shaft 11 is located on the line of action L of the resultant force F3 of the lift force F1 and the drag force F2 acting on the hydrofoil section 31, as viewed from the left-right direction. Furthermore, in the reference state S1, the first rotating central axis C1 of the first rotating shaft 11 is located forward of the line of action L of the resultant force F3 of the lift force F1 and the drag force F2 acting on the hydrofoil section 31. Therefore, in the reference state S1, a moment about the first rotating central axis C1 is generated on the wing member 3 by the resultant force F3, although it is a small moment. The direction of this moment is such that the wing member 3 rotates rearward, because the first rotating central axis C1 is located forward of the line of action L of the resultant force F3.

[0080] Therefore, in the reference state S1, the hydraulic cylinder 4 constantly applies a small holding force to the wing member 3 to maintain the position (angle of attack) of the wing member 3 against a small moment that tends to rotate the wing member 3 rearward. In the reference state S1, the moment is small, so the load on the hydraulic cylinder 4 is small. Furthermore, because the first rotation central axis C1 is located forward of the line of action L of the resultant force F3, if the hydraulic cylinder 4 is no longer able to hold the position of the wing member 3 due to damage to the hydraulic cylinder 4 or large resistance from the water acting on the hydrofoil section 31, the wing member 3 will rotate rearward, where the angle of attack will decrease. In this case, the wing member 3 and the swivel bracket 2 rotate rearward around the first rotation central axis C1, bouncing upward. The swivel bracket 2 then comes into contact with the buffer member 13.

[0081] (Effects of the embodiment) In this embodiment, the following effects can be obtained.

[0082] As described above, this embodiment includes a wing member 3 including a hydrofoil section 31 and a strut section 30, and a rotation actuator (hydraulic cylinder 4) that rotates the wing member 3 back and forth about a first rotation central axis C1 to change the angle of attack of the hydrofoil section 31, and in a reference state S1 in which the angles of attack of the hydrofoil sections 31 of a pair of hydrofoil module sections 103a on both sides in the transverse direction of the hull 101 are the same, the first rotation shaft 11 is located forward of the center of area P1 of the hydrofoil section 31. Here, it is known that the center of lift P2, which is the point of action at which lift F1 acts on the hydrofoil section 31 in the horizontal direction, is located forward of the center of area P1 of the hydrofoil section 31. Therefore, with the above configuration, in the reference state S1, by positioning the first pivot shaft 11 closer to the lift center P2, which is forward of the center of area P1 of the hydrofoil section 31, the line of action L of the resultant force F3 of the lift force F1 and drag force F2 of the hydrofoil section 31 can be positioned relatively close to the first pivot shaft 11. This reduces the moment about the first pivot central axis C1 generated by the resultant force F3 of the hydrofoil section 31 in the reference state S1. As a result, in the reference state S1, the load on the rotation actuator (hydraulic cylinder 4) for changing and maintaining the angle of attack of the hydrofoil section 31 can be reduced. Furthermore, the vessel includes a clamp bracket 1 detachably attached to the hull 101 and a swivel bracket 2 rotatably attached to the clamp bracket 1 via the first pivot shaft 11, and the wing member 3 is attached to the swivel bracket 2. This allows the swivel bracket 2 and the wing member 3 to be attached to the hull 101 simply by attaching the clamp bracket 1 to the hull 101, making it easy to attach the hydrofoil module 103 to the hull 101.

[0083] In this embodiment, as described above, in the reference state S1, the first pivot shaft 11 is disposed forward of the center of area P1 of the hydrofoil section 31 and rearward of the leading edge 31a of the hydrofoil section 31. Here, it is known that the lift center P2, which is the point of application of lift F1 on the hydrofoil section 31 in the longitudinal direction, is located rearward of the leading edge 31a of the hydrofoil section 31. Therefore, with the above-described configuration, in the reference state S1, the first pivot shaft 11 is disposed on the lift center P2 side, which is rearward of the leading edge 31a of the hydrofoil section 31, and the line of action L of the resultant force F3 of the lift F1 and drag F2 of the hydrofoil section 31 can be disposed closer to the first pivot shaft 11. As a result, in the reference state S1, the load on the rotation actuator (hydraulic cylinder 4) for changing and maintaining the angle of attack of the hydrofoil section 31 can be further reduced.

[0084] In this embodiment, as described above, the clamp bracket 1 is formed in the shape of a plate having bolt holes 10 through which bolts B for fixing the clamp bracket 1 to the hull 101 are passed, and is detachably fixed to the hull 101 by the bolts B passed through the bolt holes 10. This makes it easier to attach the hydrofoil module 103 to the hull 101 by the bolts B passed through the bolt holes 10 of the clamp bracket 1.

[0085] In this embodiment, as described above, the reference angle of attack A1, which is the angle of attack of the hydrofoil section 31 in the reference state S1, is set to a predetermined angle of 4 degrees or more and 8 degrees or less. By setting the hydrofoil section 31 to the reference angle of attack A1 of 4 degrees or more and 8 degrees or less, it is possible to generate an upward lift F1 that can stably raise the hull 101 during navigation.

[0086] In this embodiment, as described above, the initial angle of attack A2, which is the angle of attack of the hydrofoil section 31 when the strut section 30 extends vertically, is greater than 0 degrees and less than the reference angle of attack A1. As a result, at the reference angle of attack A1, which is greater than the initial angle of attack A2, the lower end 30a of the strut section 30 is positioned forward of the upper end 30b, and the inclination direction of the strut section 30 can be made to be along the line of action L of the resultant force F3 of the drag force F2 and the lift force F1 acting on the hydrofoil section 31. As a result, the resultant force F3 of the drag force F2 and the lift force F1 acting on the hydrofoil section 31 can be made to act along the longitudinal direction of the strut section 30, and the resultant force F3 can be effectively transmitted to the hull 101.

[0087] In this embodiment, as described above, in the reference state S1, the strut sections 30 are inclined so that the lower ends 30a are positioned further forward than the upper ends 30b, and extend in a direction along the line of action L of the resultant force F3 of the lift force F1 and the drag force F2 acting on the hydrofoil section 31. This makes it possible to generate a resultant force F3 that pushes up the strut sections 30 along the direction in which the strut sections 30 extend, thereby raising the hull 101. Therefore, the resultant force F3 can be used to effectively raise the hull 101 via the strut sections 30.

[0088] In this embodiment, as described above, the swivel bracket 2 includes the second rotation shaft 23 having a second rotation center axis C2 extending in the fore-and-aft direction, and rotatably supports the wing member 3 via the second rotation shaft 23. The wing member 3 is configured to rotate about the second rotation center axis C2 to switch between an underwater position where the hydrofoil section 31 is located underwater, and an above-water position where the hydrofoil section 31 is located above the water. This allows the wing member 3 to switch between the underwater position and the above-water position without moving the hydrofoil section 31 in the fore-and-aft direction, where it experiences relatively large resistance from the water.

[0089] In this embodiment, as described above, the rotation actuator is the hydraulic cylinder 4 that expands and contracts to press against the swivel bracket 2 and rotate the swivel bracket 2 about the first rotation central axis C1, and one end 40a of the hydraulic cylinder 4 is attached to the clamp bracket 1, and the other end 41a of the hydraulic cylinder 4 is attached to the swivel bracket 2. This makes it possible to easily rotate the swivel bracket 2 about the first rotation central axis C1 relative to the clamp bracket 1 by the hydraulic cylinder 4. Furthermore, because the hydraulic cylinder 4 is attached to the clamp bracket 1 and the swivel bracket 2, simply attaching the clamp bracket 1 to the hull 101 completes the installation of the hydraulic cylinder 4 to the hull 101.

[0090] As described above, this embodiment further includes a hydraulic oil supply device 5 that includes a pump unit 50 that supplies hydraulic oil to the hydraulic cylinder 4 and a motor unit 51 that drives the pump unit 50 and is attached to the clamp bracket 1. This allows the hydraulic cylinder 4 to be easily driven by the motor unit 51 that drives the pump unit 50. Furthermore, because the hydraulic oil supply device 5 is attached to the clamp bracket 1, simply attaching the clamp bracket 1 to the hull 101 completes the attachment of the hydraulic oil supply device 5 to the hull 101.

[0091] In this embodiment, as described above, the hydraulic cylinder 4 and the hydraulic oil supply device 5 are arranged side by side in the left-right direction and are arranged behind the first rotating shaft 11. This allows the hydraulic cylinder 4 and the hydraulic oil supply device 5 to be arranged side by side in the left-right direction, thereby reducing the size of the device in the front-to-rear direction. In addition, the angle of attack can be changed by the hydraulic cylinder 4 pressing the first rotating shaft 11 from behind.

[0092] In this embodiment, as described above, the other end 41a of the hydraulic cylinder 4 is disposed forward of the one end 40a of the hydraulic cylinder 4 and above the first rotating shaft 11, and the hydraulic cylinder 4 is configured to extend the rod 41 to rotate the wing member 3 rearward to decrease the angle of attack, and to retract the rod 41 to rotate the wing member 3 forward to increase the angle of attack. This allows the other end 41a of the hydraulic cylinder 4 to be disposed above the first rotating shaft 11, thereby reducing the size of the device in the horizontal direction (front-to-rear direction).

[0093] In this embodiment, as described above, in the reference state S1, the first pivot shaft 11 is positioned, when viewed from the left-right direction, on the line of action L of the resultant force F3 of the lift force F1 and the drag force F2 acting on the hydrofoil section 31. This allows the line of action L of the resultant force F3 to be positioned closer to the first pivot central axis C1 in the reference state S1, and therefore the moment about the first pivot central axis C1 generated by the resultant force F3 of the hydrofoil section 31 in the reference state S1 can be made extremely small.

[0094] In this embodiment, as described above, in the reference state S1, the first rotation central axis C1 of the first rotating shaft 11 is located forward of the line of action L of the resultant force F3 of the lift force F1 and the drag force F2 acting on the hydrofoil section 31. As a result, if the rotation actuator (hydraulic cylinder 4) is unable to maintain the angle of attack of the wing member 3 due to, for example, a large resistance acting on the hydrofoil section 31 from the water, the wing member 3 can be rotated rearward, where the angle of attack becomes smaller, and it is possible to prevent the wing member 3 from rotating forward, thereby preventing the stability of the hull 101 from being impaired.

[0095] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0096] For example, in the above embodiment, the hydrofoil section is switched from the underwater position to the above-water position by the user manually pulling the rope around the second rotation axis, but the present invention is not limited to this. In the present invention, a hydrofoil module 203 may be provided with a rotating unit 206, as in the hydrofoil module 203 shown in FIG. 10 . The rotating unit 206 is configured to mechanically rotate the wing member 3 around the second rotation axis C2. The rotating unit 206 includes a shaft member 206a extending along the second rotation axis C2, a rack member 206b extending in the vertical direction, a pinion member 206c provided at the end of the shaft member 206a, and a drive source 206d. The shaft member 206a is fixed to the wing member 3 and configured to rotate together with the wing member 3. The rack member 206b is configured to be moved in the vertical direction by the drive source 206d. As the rack portion 206b moves up and down, the pinion portion 206c rotates around the second rotation center axis C2 together with the wing member 3, switching the underwater position and the above-water position of the hydrofoil portion 31. The drive source 206d is a hydraulic pump driven by a motor. That is, oil chambers (not shown) are provided at both ends of the rack portion 206b for pressing and moving the rack portion 206b. The drive source may be configured by a solenoid or a gear unit that transmits the torque of the motor to the rack portion.

[0097] In addition, in the above embodiment, an example has been shown in which the boat is propelled by an outboard motor, but the present invention is not limited to this. In the present invention, the boat may be propelled by an inboard motor or an inboard-outboard motor, etc.

[0098] In addition, in the above embodiment, an example has been shown in which the hull is a monohull, but the present invention is not limited to this, and the hull may also be a catamaran.

[0099] In addition, in the above embodiment, an example was shown in which the reference angle of attack was set to 6 degrees, but the present invention is not limited to this. In the present invention, the reference angle of attack may be set to an angle other than 6 degrees.

[0100] In addition, in the above embodiment, an example was shown in which the initial angle of attack was set to 3 degrees, but the present invention is not limited to this. In the present invention, the initial angle of attack may be set to an angle other than 3 degrees.

[0101] In the above embodiment, the rotation actuator of the present invention is configured by a hydraulic cylinder, but the present invention is not limited to this. In the present invention, the rotation actuator may be configured by a solenoid or the like.

[0102] In addition, in the above embodiment, an example was shown in which the first pivot shaft was located behind the leading edge of the hydrofoil section in the reference state, but the present invention is not limited to this. In the present invention, the first pivot shaft may be located in front of the hydrofoil section in the reference state, or may be located at the same position in the fore-and-aft direction as the hydrofoil section in the reference state.

[0103] In addition, while the above embodiment shows an example in which the clamp bracket is fixed to the hull with bolts, the present invention is not limited to this. In the present invention, the clamp bracket may be fixed to the hull with a member that sandwiches the clamp bracket and the hull.

[0104] In the above embodiment, the hydraulic oil supply device is attached directly to the clamp bracket, but the present invention is not limited to this. In the present invention, the hydraulic oil supply device may be attached directly to the swivel bracket.

[0105] In the above embodiment, the first pivot shaft is disposed on the line of action of the resultant force of lift and drag acting on the hydrofoil portion when viewed from the left and right, but the present invention is not limited to this. In the present invention, the first pivot shaft may be disposed at a position that is off the line of action of the resultant force of lift and drag acting on the hydrofoil portion when viewed from the left and right, in the reference state.

[0106] In addition, in the above-described embodiment, an example has been shown in which the hydraulic cylinder and the hydraulic oil supply device are arranged side by side in the left-right direction, but the present invention is not limited to this. In the present invention, the hydraulic cylinder and the hydraulic oil supply device may be arranged side by side in the front-rear direction.

[0107] In addition, in the above-described embodiment, an example has been shown in which the hydraulic cylinder is disposed behind the first rotating shaft, but the present invention is not limited to this. In the present invention, the hydraulic cylinder may be disposed in front of the first rotating shaft.

[0108] In addition, in the above-described embodiment, an example has been shown in which the hydraulic oil supply device is disposed behind the first rotating shaft, but the present invention is not limited to this. In the present invention, the hydraulic oil supply device may be disposed in front of the first rotating shaft. [Explanation of symbols]

[0109] 1 Clamp bracket 2 Swivel Brackets 3 Wing members 4 Hydraulic cylinder (rotation actuator) 5 Hydraulic oil supply device 10 Bolt holes (in clamp bracket) 11 First rotating shaft 23 Second rotating shaft 30 Strut section 30a Lower end (of strut) 30b (Strut section) upper end 31 Hydrofoil section 31a leading edge 40a (One end of hydraulic cylinder) 41 Rod 41a (the other end of the hydraulic cylinder) 50 Pump section (of hydraulic oil supply device) 51 (hydraulic oil supply device) motor section 100 ships 101 Hull 103, 203 Hydrofoil Module 103a Hydrofoil module A1 Reference angle of attack (the angle of attack under the reference condition) A2 (initial angle of attack) B Bolt C1 First rotation center axis C2 Second rotation center axis F1 Lift F2 drag F3 Resultant force (of lift and drag) L Line of action (of resultant lift and drag forces) S1 Reference condition P1 center of area

Claims

1. a clamp bracket including a first rotation shaft having a first rotation center axis extending in the left-right direction and removably attached to the hull; a swivel bracket rotatably attached to the clamp bracket via the first rotation shaft; a wing member including a hydrofoil portion disposed underwater and a columnar strut portion having a lower end to which the hydrofoil portion is provided and an upper end to which the swivel bracket is attached; a rotation actuator that rotates the wing member together with the swivel bracket back and forth around the first rotation center axis to change the angle of attack of the hydrofoil section, a pair of hydrofoil module sections provided on both sides of the hull in the left-right direction, each of which includes the clamp bracket, the swivel bracket, the wing member, and the rotation actuator, are configured to apply lift to the hull during navigation, thereby lifting the hull; A hydrofoil module, wherein in a reference state in which the angles of attack of the hydrofoil sections of a pair of the hydrofoil module sections are the same, the first rotation axis is positioned forward of the center of area of ​​the hydrofoil sections.

2. The hydrofoil module according to claim 1 , wherein in the reference state, the first rotation axis is located forward of the center of area of ​​the hydrofoil section and rearward of the leading edge of the hydrofoil section.

3. A hydrofoil module as described in claim 1, wherein the clamp bracket is formed in the shape of a plate having bolt holes through which bolts for fixing the clamp bracket to the hull are passed, and the clamp bracket is removably fixed to the hull by the bolts passed through the bolt holes.

4. The hydrofoil module according to claim 1 , wherein a reference angle of attack, which is an angle of attack of the hydrofoil section in the reference state, is set to a predetermined angle of 4 degrees or more and 8 degrees or less.

5. The hydrofoil module according to claim 4 , wherein an initial angle of attack, which is an angle of attack of the hydrofoil portion when the strut portion extends vertically, is greater than 0 degrees and less than the reference angle of attack.

6. A hydrofoil module as described in claim 1, wherein, in the reference state, the strut section is inclined so that the lower end is positioned forward of the upper end, and extends in a direction along the line of action of the resultant force of lift and drag acting on the hydrofoil section.

7. the swivel bracket includes a second rotation shaft having a second rotation center axis extending in the front-rear direction, and rotatably supports the wing member via the second rotation shaft; The hydrofoil module described in claim 1, wherein the wing member is configured to rotate around the second pivot center axis to switch between an underwater position in which the hydrofoil section is positioned underwater and an above-water position in which the hydrofoil section is positioned above the water.

8. the rotation actuator is a hydraulic cylinder that expands and contracts to press the swivel bracket and rotate the swivel bracket around the first rotation central axis, One end of the hydraulic cylinder is attached to the clamp bracket, The hydrofoil module of claim 1 , wherein the other end of the hydraulic cylinder is attached to the swivel bracket.

9. The hydrofoil module according to claim 8 , further comprising a hydraulic oil supply device attached to the clamp bracket, the hydraulic oil supply device including a pump unit that supplies hydraulic oil to the hydraulic cylinder and a motor unit that drives the pump unit.

10. The hydrofoil module according to claim 9 , wherein the hydraulic cylinder and the hydraulic oil supply device are arranged side by side in the left-right direction and are arranged rearward of the first rotation shaft.

11. the other end of the hydraulic cylinder is disposed forward of the one end of the hydraulic cylinder and above the first rotation shaft, 11. The hydrofoil module of claim 10, wherein the hydraulic cylinder is configured to extend the rod to rotate the wing member rearward to decrease the angle of attack, and to retract the rod to rotate the wing member forward to increase the angle of attack.

12. The hydrofoil module according to claim 1, wherein in the reference state, the first rotation axis is arranged on a line of action of a resultant force of lift and drag acting on the hydrofoil portion when viewed from the left-right direction.

13. The hydrofoil module according to claim 1, wherein in the reference state, the first pivot center axis of the first pivot shaft is positioned forward of the line of action of the resultant force of lift and drag acting on the hydrofoil portion.

14. The hull and a hydrofoil module provided on the hull, The hydrofoil module comprises: a clamp bracket having a first rotation shaft with a first rotation center axis extending in the left-right direction and removably attached to the hull; a swivel bracket rotatably attached to the clamp bracket via the first rotation shaft; a wing member having a hydrofoil portion disposed in water and a columnar strut portion having a lower end to which the hydrofoil portion is provided and an upper end to which the swivel bracket is attached; a rotation actuator that rotates the wing member together with the swivel bracket back and forth around the first rotation center axis to change the angle of attack of the hydrofoil section, a pair of hydrofoil module sections provided on both sides of the hull in the left-right direction, each of which includes the clamp bracket, the swivel bracket, the wing member, and the rotation actuator, are configured to apply lift to the hull during navigation, thereby lifting the hull; A ship, wherein in a reference state in which the angles of attack of the hydrofoil sections of a pair of the hydrofoil module sections are the same, the first pivot axis is positioned forward of the center of area of ​​the hydrofoil sections.

15. The watercraft according to claim 14 , wherein in the reference state, the first rotation axis is disposed forward of the center of area of ​​the hydrofoil section and rearward of a leading edge of the hydrofoil section.

16. 15. The watercraft according to claim 14, wherein the clamp bracket is formed in a plate shape having bolt holes through which bolts for fixing the clamp bracket to the hull are passed, and the clamp bracket is detachably fixed to the hull by the bolts passed through the bolt holes.

17. The watercraft according to claim 14 , wherein a reference angle of attack, which is an angle of attack of the hydrofoil section in the reference state, is set to a predetermined angle of 4 degrees or more and 8 degrees or less.

18. The watercraft according to claim 17 , wherein an initial angle of attack, which is an angle of attack of the hydrofoil portion when the strut portion extends in the vertical direction, is greater than 0 degrees and less than the reference angle of attack.

19. 15. The watercraft according to claim 14, wherein, in the reference state, the strut section is inclined so that the lower end is positioned forward of the upper end, and extends in a direction along a line of action of a resultant force of lift and drag acting on the hydrofoil section.

20. the swivel bracket includes a second rotation shaft having a second rotation center axis extending in the front-rear direction, and rotatably supports the wing member via the second rotation shaft; The vessel described in claim 14, wherein the wing member is configured to rotate around the second pivot center axis to switch between an underwater position in which the underwater wing section is positioned underwater and an above-water position in which the underwater wing section is positioned above the water.

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