Submersible hydrofoil boat, and floatation and submersion method of submersible hydrofoil boat

Abstract

To provide a submersible hydrofoil boat, and a floatation and submersion method of the submersible hydrofoil boat capable of performing a floating navigation under small waves and requiring a high speed, and capable of performing a submerging navigation under big waves and requiring a stealth property.SOLUTION: A submersible hydrofoil boat 1 or 1A is constituted by having a main hull 10 and a hydrofoil 20 arranged at a distance from the main hull 10. The submersible hydrofoil boat is configured so as to generate upward lift Lu by the hydrofoil 20 when navigating by raising the main hull 10 from a stopping position, and generate downward lift Ld by the hydrofoil 20 when navigating under the submerging the main hull 10 from the stopping position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a submersible hydrofoil vessel and a method for surfacing and submerging a submersible hydrofoil vessel, and more particularly to a submersible hydrofoil vessel and a method for surfacing and submerging a submersible hydrofoil vessel, which has hydrofoils on the main hull and can temporarily submerge the main hull to allow it to submerge. [Background technology]

[0002] Conventional hydrofoil vessels use semi-submersible hydrofoils (such as V-shaped hydrofoils) where part of the hydrofoil is above the water surface when traveling at high speeds, or fully submersible hydrofoils (such as horizontal hydrofoils) where the entire hydrofoil is below the water surface, generating upward lift that keeps the main hull completely above the water surface. In conventional technology, these hydrofoil vessels do not submerge the main hull. Furthermore, when it comes to unmanned vehicles, drones, and other such vessels, vessels that travel on the water surface (unmanned surface vehicles (USVs)) and vessels that travel submerged (unmanned underwater vehicles (UUVs)) are considered to be different types of vessels.

[0003] On the other hand, semi-submersible vessels and mini-submarines have come to be used as relatively small vessels for smuggling. However, while submarines and other vessels that primarily navigate underwater and temporarily navigate on the surface have been put to practical use, there are almost no vessels that primarily navigate on the surface and are also capable of underwater navigation.

[0004] For example, an unmanned surface vehicle (ASV) equipped with a cooling structure for cooling heat-generating elements has been proposed as a surface vehicle (see, for example, Patent Document 1). Also, a surface vehicle equipped with a water jet propulsion unit has been proposed (see, for example, Patent Document 2). All of these main hulls have a displacement type hull shape.

[0005] Furthermore, many underwater vehicles generally have torpedo-shaped or cylindrical hulls. For example, an underwater vehicle capable of rapid submerged navigation and horizontal navigation with low energy consumption has been proposed (see, for example, Patent Document 3). This underwater vehicle is formed with an underwater vehicle main body having a streamlined front end that faces the direction of travel during horizontal navigation, ballast whose rear end is fitted into the front end of the underwater vehicle main body and whose front end is also streamlined, and ballast holding means that detachably holds the ballast at the front end of the underwater vehicle main body.

[0006] Meanwhile, with regard to hydrofoil vessels, a fully submerged hydrofoil vessel has been proposed that has a pair of front and rear fully submerged hydrofoils, each equipped with a plurality of strain gauges arranged on a pair of left and right struts that support the hydrofoil or each hydrofoil, and a flap control circuit that controls the flaps of each hydrofoil based on the output signals of each strain gauge (see, for example, Patent Document 4).The purpose of this fully submerged hydrofoil is to reduce the motion of the hull and stabilize its attitude even when the foil is sailing through waves. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2019-142368 [Patent Document 2] Japanese Patent Application Publication No. 2018-135037 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-47094 [Patent Document 4] Japanese Patent Application Publication No. 7-187055 Summary of the Invention [Problem to be solved by the invention]

[0008] In this hydrofoil vessel, the main hull is above the water surface, and only the hydrofoils and their support parts are subjected to water resistance, which reduces propulsion resistance and enables high-speed sailing with low fuel consumption. However, because the lift of the hydrofoils changes as the submerged depth changes, the hydrofoils are susceptible to the effects of waves when propelling through rough waves, and in rough weather, there is a risk that the hydrofoils may hit the bottom of the main hull if the waves get high.

[0009] The present invention has been made in consideration of the above, and an object of the present invention is to provide a submersible hydrofoil vessel and a method of surfacing and submerging a submersible hydrofoil vessel that can navigate at high speed by surface navigation when waves are small, and can submerge and navigate underwater when waves are large or stealth is required. [Means for solving the problem]

[0010] The submersible hydrofoil vessel of the present invention, which is intended to achieve the above-mentioned objectives, is configured to have a main hull and hydrofoils arranged at a distance from the main hull, and is characterized in that it generates upward lift on the hydrofoils to raise the main hull from a stationary state and sail, and generates downward lift on the hydrofoils to submerge the main hull from a stationary state and sail.

[0011] This submersible hydrofoil vessel can generate not only upward lift but also downward lift (sinking force) with its hydrofoils, allowing it to sail not only with the main hull raised from a stationary position but also with the main hull submerged from a stationary position, thereby expanding its applications. Surface navigation allows high-speed navigation and good fuel efficiency, allowing it to sail long distances at high speeds, while submerged navigation allows it to avoid waves in rough weather, ensures anti-radar and stealth capabilities, and reduces visibility.

[0012] However, in civilian use, the only time this submersible hydrofoil vessel would need to navigate submerged would be if the weather suddenly changed and it encountered rough seas, and in reality, if it was determined that the weather was unsafe to navigate based on forecasts, it would be suspended, so it is thought that there would be almost no need for it to navigate submerged. Therefore, it is thought that there would be almost no civilian use for this type of vessel.

[0013] On the other hand, from a military perspective, because it can travel long distances at high speeds while surfaced, it can be launched from outside the enemy's attack range (out-range). Furthermore, because the wake left when surfaced is small, it improves visibility and stealth against searches from the air. Furthermore, when in an area where it is easily detected by enemy radar or when it is being searched by enemy radar, it can switch to submerged navigation, reducing the radar area above the water surface and improving anti-radar and stealth capabilities. Furthermore, because it can almost completely eliminate its wake, it can also reduce visibility.

[0014] Furthermore, unmanned submersible hydrofoils for suicide bombing and submersible hydrofoils for launching short torpedoes can attack underwater areas of enemy ships, where damage is greatest. Furthermore, by operating submerged, especially fully submerged, these submersible hydrofoils may be able to avoid surface attacks by enemy anti-ship missiles, machine guns, close-in defense systems, etc.

[0015] Furthermore, compared to torpedoes, submersible hydrofoils have a larger volume, and when traveling semi-submerged in shallow depths, they can be snorkeled using a diesel engine, allowing for long-distance navigation, and are inexpensive to manufacture. Furthermore, by providing a sail equipped with antennas and optical equipment, they can perform radar searches, detect enemy radar waves, optical detection, and exchange information with friendly forces via radio when traveling semi-submerged, such as when surfacing or snorkeling.

[0016] Therefore, in military applications, submersible hydrofoils could be used as suicide vehicles for attacking unmanned surface vehicles (USVs), as mother ships for launching short-range torpedoes, etc. Furthermore, they could be used as small craft for supporting and recovering infiltrators from the landing, rescuing pilots, and for landing.

[0017] The submersible hydrofoil vessel is also characterized in that it can perform surfaced navigation, in which upward lift is generated on the hydrofoils, causing the main hull to be in a surfaced or semi-surfaced state and sailing, and submerged navigation, in which downward lift is generated on the hydrofoils, causing the main hull to be in a fully submerged or semi-submerged state and sailing.

[0018] The terms "hull surfaced" and "semi-surfaced" refer to a state in which the hull is completely surfaced relative to the still water surface. Furthermore, "semi-surfaced" refers to a state in which the volume Vmu of the hull above the water surface is 50% or more but less than 100% of the volume Vmt of the hull (0.50≦(Vmu / Vmt)<1.00).

[0019] "Semi-submerged" refers to a state in which the volume Vmu of the main hull above the water surface relative to the still water surface is greater than 0% and less than 50% of the volume Vmt of the main hull (0.00<(Vmu / Vmt)<0.50). "Completely submerged" refers to a state in which the main hull is completely submerged relative to the still water surface.

[0020] The terms "navigation" and "semi-surfaced navigation" used here refer to the following: "navigation with the main hull surfaced" refers to navigation with the "main hull surfaced," and "semi-surfaced navigation" refers to navigation in a "semi-surfaced state." Furthermore, "fully submerged navigation" refers to navigation in a "fully submerged state," and "semi-submerged navigation" refers to navigation in a "semi-submerged state." "Navigation with the main hull surfaced" and "semi-submerged state" are collectively referred to as "surfaced navigation." Furthermore, "fully submerged navigation" and "semi-submerged navigation" are collectively referred to as "submerged navigation."

[0021] "Semi-submerged navigation" includes "semi-submerged main hull navigation," in which more than half of the main hull is submerged, but part of the main hull is raised above the water surface; "surfaced sail navigation," in which the entire main hull is submerged, but part or all of the sails are raised above the water surface; and "periscope depth navigation," in which the sails are also submerged, but periscopes and other equipment are raised above the water surface.

[0022] In the above-mentioned submersible hydrofoil vessel, if the hydrofoil is a fully submersible hydrofoil, the hydrofoil is submerged to a great depth, so that, like the fully submersible hydrofoil vessels of the prior art, the fluctuation of lift caused by the influence of the water surface (free surface) is small and the lift is large, resulting in low propulsion resistance. In addition, there is the advantage that the lift can be easily controlled during surfaced and submerged navigation.

[0023] Furthermore, in the above-mentioned submersible hydrofoil vessel, if the hydrofoil is a semi-submersible hydrofoil, it can navigate in shallow waters, just like semi-submersible hydrofoil vessels in the prior art, and has the advantage of being easy to control roll, as the hydrofoil provides the restoring force against roll and other movements during surfaced navigation.

[0024] Furthermore, if the submersible hydrofoil vessel is equipped with a wing lifting mechanism that changes the distance between the main hull and the hydrofoils, the submerged depth of the hydrofoils can be changed depending on the wave conditions on the water surface and the depth of the navigation area during surfaced and submerged navigation, allowing the hydrofoils to perform more effectively and be made smaller.Furthermore, by abutting the hydrofoils against the bottom of the main hull, the vessel can be used as a displacement vessel or a planing vessel to navigate in shallow waters.

[0025] Alternatively, if the submersible hydrofoil vessel is provided with a mechanism for storing the hydrofoils inside or in contact with the main hull and deploying the stored hydrofoils, storing the hydrofoils during submerged navigation can reduce propulsion resistance and improve propulsion efficiency. When the vessel is ready to surface again, the hydrofoils can be deployed for surface navigation.

[0026] Alternatively, if the submersible hydrofoil vessel is provided with a wing separation mechanism for separating the hydrofoils from the main hull, separating the hydrofoils during submerged navigation can reduce the propulsion resistance and mass during submerged navigation, thereby significantly improving propulsion efficiency. In this case, after the hydrofoils are separated, they cannot be used again for surfacing navigation.

[0027] The method for surfacing and sinking a submersible hydrofoil vessel of the present invention is a method for a submersible hydrofoil vessel having a main hull and hydrofoils arranged at a distance from the main hull, characterized in that when the main hull is raised from a stationary state to float and used for navigation, the hydrofoils generate upward lift, and when the main hull is submerged from a stationary state to navigate, the hydrofoils generate downward lift.

[0028] According to this method for surfacing and lowering a submersible hydrofoil vessel, by configuring the hydrofoils to generate downward lift in addition to upward lift, the main hull can be lowered from a stationary state and used for sailing. In other words, simply by widening the range of motion of the hydrofoils or hydrofoil flaps, the main hull can be lowered from a stationary state and used for sailing. As a result, the uses of submersible hydrofoil vessels can be expanded. Furthermore, with this submersible hydrofoil vessel, there is no need to add or remove ballast water from ballast tanks for lowering the vessel, as is the case with submarines. Furthermore, by limiting the submergence depth during submerged sailing to a shallow depth, a pressure-resistant structure is not required, and the structure of the main hull can be simplified.

[0029] Furthermore, in the method for surfacing and sinking a submersible hydrofoil vessel, when sailing, the hydrofoils generate upward lift to raise the main hull from a stopped state, or the hydrofoils generate downward lift to submerge the main hull from a stopped state, thereby sailing with the main hull in one of the following states: floated, semi-floated, semi-submerged, or fully submerged.

[0030] This method allows a submersible hydrofoil vessel to utilize the upward and downward lift forces of the hydrofoils. Therefore, even if the vessel is configured to be stopped in various states from fully submerged to semi-floated, the main hull can be set to be fully submerged, semi-submerged, semi-floated, or fully surfaced. This allows for more flexible selection of the vessel's stopping state depending on the application, thereby expanding the range of uses for submersible hydrofoil vessels. For example, when recovering submersibles or rescuing pilots, the vessel can be stopped and waited in a fully submerged or semi-submerged state. Furthermore, by providing the main hull with buoyancy sufficient to maintain afloatation when stopped, the vessel can safely maintain afloatation without sinking even in the event of a hydrofoil failure.

[0031] In the method for raising and lowering a submersible hydrofoil vessel described above, if ballast water is discharged from the ballast tanks when the main hull is raised from a stationary state, and ballast water is poured into the ballast tanks when the main hull is submerged from a stationary state, the main hull can be raised and lowered with a smaller hydrofoil lift, thereby making it possible to reduce the size of the hydrofoils. Note that these ballast tanks can be provided on the main hull, hydrofoils, struts, etc., or can be provided as auxiliary tanks that can be detached. [Effects of the Invention]

[0032] The submersible hydrofoil vessel and the method for surfacing and submerging a submersible hydrofoil vessel of the present invention can provide a submersible hydrofoil vessel with a relatively simple configuration that can surface and navigate long distances at high speeds when waves are small, and can navigate submerged when waves are large or secrecy is required. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a diagram showing a submersible hydrofoil vessel according to a first embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing the propulsion mechanism and sail of a submersible hydrofoil vessel. [Figure 3] This is a diagram showing a configuration in which a rudder and a horizontal rudder for diving are provided on the main hull of a submersible hydrofoil vessel. [Figure 4]1A-1C are diagrams showing various surfaced and submerged states of a submersible hydrofoil vessel; [Figure 5] 1 is a diagram showing the relationship between the water surface during various surfaced and submerged navigation of a submersible hydrofoil vessel. [Figure 6] FIG. 1 is a diagram showing the relationship between various surface navigations of a submersible hydrofoil vessel and the lift force of the hydrofoil. [Figure 7] 1 is a diagram showing the relationship between various submerged navigational states of a submersible hydrofoil vessel and the lift force of the hydrofoil. [Figure 8] 1A and 1B are diagrams showing the state of raising and lowering of hydrofoils in a submersible hydrofoil vessel. [Figure 9] 1A and 1B are diagrams showing the retracted and deployed states of hydrofoils in a submersible hydrofoil vessel. [Figure 10] 1A and 1B are diagrams showing the deployment and separation of hydrofoils in a submersible hydrofoil vessel. [Figure 11] FIG. 10 is a diagram showing a submersible hydrofoil vessel according to a second embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0034] [Introduction] Below, a submersible hydrofoil vessel and a method for surfacing and sinking the submersible hydrofoil vessel according to an embodiment of the present invention will be described with reference to the drawings. The coordinate system "XYZ" used in the drawings indicates a right-handed coordinate system in which the fore-and-aft direction of the submersible hydrofoil vessel is the X direction, the left-and-right direction is the Y direction, and the up-and-down direction is the Z direction, with the forward, left, and up directions all being positive.

[0035] The size of the submersible hydrofoil vessel envisaged in this invention is equivalent to that of unmanned vehicles and boats, warships, ships, etc., which are currently in operation as hydrofoil vessels, and is assumed to be approximately 30m in length, 9m in width, 3m in depth, and up to 300 tons in gross tonnage.

[0036] The hydrofoil 20 provided on the submersible hydrofoil vessel 1 of the first embodiment is a fully submersible hydrofoil that is fully submerged below the water surface during surface navigation. The front hydrofoil 20A provided on the submersible hydrofoil vessel 1A of the second embodiment is a semi-submersible hydrofoil that is not fully submerged but remains partially above the water surface during surface navigation. The submersible hydrofoil vessel of the present invention may be equipped with either a fully submersible hydrofoil or a semi-submersible hydrofoil, or may be equipped with both.

[0037] [Submersible Hydrofoil Ship of the First Embodiment] First, we will explain the submersible hydrofoil ship 1 of the first embodiment according to the present invention. As shown in Figures 1 to 3, this submersible hydrofoil ship 1 is composed of a main hull 10, fully submersible hydrofoils 20, a propulsion mechanism 12, a control mechanism 13, etc.

[0038] [Main Hull] The main hull 10 may be either a monohull or a catamaran, as in conventional hydrofoil vessels, or may have a different shape. The main hull 10 is normally constructed to be watertight when submerged in the fully submerged state C4 or the semi-submerged state C3 as shown in Figure 4. However, the submersible hydrofoil vessel 1 does not dive as deep as a submarine, but travels at shallower depths. Therefore, the main hull 10 need only be constructed to withstand submersion, and does not need to have a pressure hull like a submarine.

[0039] For example, a very large tanker (VLCC) has a draft of about 20 m, and at this level of submergence, pressure hull materials such as those used in submarines are not required. Also, when submerging using the sinking force (downward lift) of the hydrofoils 20, it is not necessarily necessary to obtain the sinking force by injecting ballast water. In this case, ballast tanks are not required, and the structure can be simplified.

[0040] By adjusting the relationship between the weight and buoyancy of the main hull 10 depending on the application, the main hull 10 can be placed in various states when stopped, such as a floated state C1, a semi-floated state C2, a semi-submerged state C3, or a fully submerged state C4, as shown in Figure 4. Furthermore, by providing ballast tanks 15 (Figure 2(b)) and buoyancy-imparting members (such as airbags (float bladders): not shown), it becomes possible to more flexibly select the floated states C1, C2, and the submerged states C3, C4 as the state when stopped, and to easily maintain those states.

[0041] The main hull 10 is composed of a hull section 11 and, if necessary, a sail 14. The shape of the hull section 11 may be torpedo-shaped, submarine-shaped (fish-shaped, surface boat-shaped, teardrop-shaped (water drop-shaped), cigar-shaped (torpedo-shaped)), or other shapes depending on the intended use. In addition, when emphasis is placed on radar stealth, the main hull 10 is shaped as an anti-radar stealth shape. Furthermore, since the submersion depth is relatively shallow and high strength is not required, if possible, the hull is formed from radio wave-transmitting or radio wave-absorbing materials, or coated with radio wave-absorbing or acoustically absorbing materials or paints.

[0042] 2(a) and 2(b), the propulsion mechanism 12 is configured to include an internal combustion engine 12a such as a diesel engine, a propeller 12d such as a water jet propeller or a propeller, and a power transmission mechanism (not shown) between them. In addition, when the internal combustion engine 12a cannot be used in the fully submerged state C4 or when it is necessary to avoid the complexity and noise of the mechanical power transmission mechanism, a power generator 12b and an electricity storage device 12c are provided to electrically drive the propeller 12d.

[0043] The control mechanism 13 includes various devices, such as a piloting device, an electrical equipment control device, and an electronic equipment control device, for operating the submersible hydrofoil vessel 1 and controlling the various on-board devices. These controls may be performed by crew members, or by remote or autonomous unmanned control, or a combination of these. Furthermore, the control may be mechanical or electronic / electrical.

[0044] [Sail] When the vessel is submerged, a sail 14 is provided to supply and exhaust air to the engine. This sail 14 is the part that is exposed above the water surface when the vessel is semi-submerged C3, and is provided by projecting upward from the top of the hull 11. When the vessel is submerged, the horizontal cross section of the sail 14 is formed into a streamlined shape to reduce the resistance, wave generation, and wake of the sail 14.

[0045] As shown in Figure 2(c), the sail 14 is equipped with a snorkel 14a for intake and exhaust of the internal combustion engine 12a, electronic equipment 14b for determining the external situation by radio wave search on the sea, optical search on the sea, radio communication, etc., and optical equipment 14c. The electronic equipment 14b includes a radar device, a radar wave detection device, a communication device, etc. The optical equipment 14c includes an optical periscope, an optical communication device, etc.

[0046] In particular, if the submersible hydrofoil vessel 1 requires radar-resistant stealth, the sail 14 can be given an anti-radar stealth shape and painted with radar-absorbing materials to avoid radar detection. These measures are similar to those for submarine sails, but because the submergence depth is much smaller, there is no need to consider the pressure resistance of the sail, which broadens the range of materials that can be used and increases the freedom of design and manufacturing. In addition, the snorkel 14a cools the exhaust gas to avoid infrared detection.

[0047] Furthermore, by receiving information about the surrounding situation from detection devices on other ships and aircraft, refraining from radio wave emissions, and only using communication equipment with the outside, it is possible to reduce the amount of equipment carried, making the ship lighter, smaller, cheaper, and more stealthy.

[0048] Furthermore, normally, the functions for steering and diving of the submersible hydrofoil vessel 1 are provided by the hydrofoils 20 and the struts 30. However, when the hydrofoils 20 are to be stored or separated, as will be described later, the main hull 10 may be provided with steering mechanisms such as a rudder 13a and a horizontal rudder for diving 13b, as required, as shown in Figure 3.

[0049] [Hydrofoils] While the hydrofoils of conventional hydrofoil vessels generate lift only in the upward direction, the fully submersible hydrofoil 20 of this submersible hydrofoil vessel 1 generates a downward lift (sinking force) Ld in addition to an upward lift Lu. For this reason, the angle of attack of the foil is configured to be changeable both downward and upward, or the main body of the hydrofoil 20 is placed horizontally and configured to generate an upward lift Lu and a downward lift Ld by the flaps 20a.

[0050] Since the submerged depth of the fully submerged hydrofoil 20 is a depth where the free surface influence of the water is less than that of a semi-submerged hydrofoil, it is considered sufficient for the cross-sectional shape of this hydrofoil 20 to be a symmetrical foil. However, since the relationship between the weight and buoyancy of the main hull 10, and the surfaced state during surfaced navigation and the submerged state during submerged navigation, the relationship between the magnitude of the upward lift force Lu and the downward lift force Ld is determined by the relationship between the weight and buoyancy of the main hull 10, and the surfaced state during surfaced navigation and the submerged state during submerged navigation, a foil shape suitable for each case is used, taking into consideration numerical calculations, experimental results, etc.

[0051] If the hydrofoil 20 has an internal cavity, this cavity can be used as a fuel tank, but it can also be used as a ballast tank. When used as a ballast tank, it can be used to adjust the floating amount of the main hull 10. Furthermore, if the hydrofoil 20 is provided with a wing lifting mechanism 41, when the hydrofoil 20 is raised and lowered, ballast water is injected when the hydrofoil 20 is lowered and discharged when the hydrofoil 20 is raised and lowered, thereby reducing the power required to raise and lower the hydrofoil 20.

[0052] [Steering and attitude control] Steering (speed adjustment) in the longitudinal direction X is mainly performed by adjusting the thrust Ts generated by the propeller 12d, but braking forces from the flaps 20a of the hydrofoil 20, the flaps 30a of the struts 30, etc. are also used as necessary.

[0053] Furthermore, steering in the left-right direction Y (maintaining course, turning, etc.) is performed using the flaps 30a of the struts 30, but if necessary, steering force from the rudder 13a is used. If multiple propellers 12d are provided in the left-right direction Y, turning force is obtained by individually controlling the thrust Ts of these propellers 12d. Furthermore, if the configuration allows the direction in which the thrust Ts of the propellers 12d is generated to be changed, turning force is obtained by changing this generation direction. Furthermore, by tilting the hull 11 laterally, turning force can also be obtained using the lift of the hydrofoils 20.

[0054] Furthermore, for maneuvering in the vertical direction Z (depth maintenance, submersion, surfacing, etc.), lift forces Lu and Ld from the flaps 20a of the hydrofoils 20 are used, but if necessary, lift forces Lu and Ld from the submersion horizontal rudder 13b are also used. If multiple propellers 12d are provided in the vertical direction Z, the thrust forces Ts of these propellers 12d are individually controlled to obtain the force for submersion or surfacing. Also, if the configuration allows the direction in which the thrust Ts of the propellers 12d is generated to be changed, the force for submersion or surfacing can be obtained by changing this direction. Furthermore, if ballast tanks 15 are provided, the force for submersion or surfacing can be obtained by filling or discharging ballast water in the ballast tanks 15, etc.

[0055] Regarding heeling and rolling around the axis in the longitudinal direction X, the attitude of the ship is controlled to heel and the reduction of rolling is controlled by fine-tuning the lift force of the flaps 20a of the hydrofoils 20 and the flaps 30a of the struts 30 separately on the left and right. Furthermore, if multiple ballast tanks 15 are provided in the transverse direction Y, these adjustments are made by filling and discharging ballast water in the ballast tanks 15, etc.

[0056] Furthermore, with regard to the trim and pitch around the axis in the left-right direction Y, the lift forces Lu and Ld of the flaps 20a of the hydrofoils 20 spaced apart in the fore-aft direction X are adjusted to control the attitude of the trim and reduce pitch. Furthermore, if multiple ballast tanks 15 are provided in the fore-aft direction X, these adjustments are made by adjusting the inflow and outflow of ballast water to and from the ballast tanks 15, for example.

[0057] Furthermore, with regard to swaying (sway) and yaw around the vertical Z axis, the means for generating turning force are individually controlled to reduce the swaying.

[0058] [Emerged and submerged states when stationary] Next, we will explain the emerged and submerged states when stationary of the submersible hydrofoil vessel 1. Here, as shown in Figure 4, the emerged and submerged states of the submersible hydrofoil vessel 1 when stationary are classified into "fully emerged state C0," "main hull emerged state C1," "semi-emerged state C2," "semi-submerged state C3," and "fully submerged state C4."

[0059] The "fully surfaced state C0" is a state in which the main hull 10 and hydrofoils 20, in other words the entire submersible hydrofoil vessel 1, are surfaced above the water surface Ws0 relative to the still water surface. Normally, the submersible hydrofoil vessel 1 has weight, so it does not reach this state on its own, but rather occurs when it is lifted by a crane or placed in a floating dock for maintenance or inspection, etc.

[0060] Furthermore, the "main hull surfaced state C1" is a state in which the volume of the main hull 10 that is above the water surface Ws1 relative to the still water surface is 100% of the volume of the main hull 10, and part of the strut 30 is above the water surface Ws1. This state is also normally not reached by the submersible hydrofoil vessel 1 on its own, since the weight of the submersible hydrofoil vessel 1 is greater than the buoyancy of the hydrofoils 20 and the struts 30, and is a state that occurs when the vessel is lifted by a crane or the like for maintenance and inspection, etc.

[0061] The "semi-floated state C2" is a state in which the volume of the main hull 10 that floats above the water surface Ws2 relative to the still water surface is between 50% and 100% of the volume of the main hull 10. In this state, the buoyancy of the submerged parts of the submersible hydrofoil vessel 1 is greater than the weight of the submersible hydrofoil vessel 1, and more than half of the volume of the main hull 10 is floated, a state that is common in passenger ships and the like.

[0062] Furthermore, the "semi-submerged state C3" is a state in which the volume of the main hull 10 that is above the water surface Ws3 is greater than 0% and less than 50% of the volume of the main hull 10. In this state, the buoyancy of the submerged portion of the submersible hydrofoil vessel 1 is greater than the weight of the submersible hydrofoil vessel 1, but more than half of the volume of the main hull 10 is submerged. This "semi-submerged state C3" is suitable for infiltration applications that require the main hull 10 to be kept hidden in a standby state, such as for transporting infiltrators or rescuing pilots, which require stealth operations.

[0063] The "fully submerged state C4" is a state in which the volume of the main hull 10 that is above the water surface Ws3 is 0% of the volume of the main hull 10. In this state, the weight of the submersible hydrofoil vessel 1 is greater than the buoyancy of the submerged portion of the submersible hydrofoil vessel 1, and the entire submersible hydrofoil vessel 1 is completely submerged. This "fully submerged state C4" is also suitable for infiltration applications that require the main hull 10 to be kept hidden while on standby, such as for covert operations such as transporting infiltrators or rescuing pilots.

[0064] [Classification of Navigation in Each State] Next, we will explain the classification of navigation in each state of the submersible hydrofoil ship 1. Here, as shown in Figures 5 to 7, navigation in each state is classified into "main hull surfaced navigation N1," "semi-surfaced navigation N2," "semi-submerged navigation N3," "sail surfaced navigation N4," "periscope depth navigation N5," and "fully submerged navigation N6." Note that Figures 6 and 7 show the lift forces Lu and Ld generated by the hydrofoil 20 when the surfaced state of the submersible hydrofoil ship 1 when stopped is the semi-surfaced state C2. Therefore, the vertical direction of the lift generated by the hydrofoil 20 when the surfaced state of the submersible hydrofoil ship 1 when stopped is not the semi-surfaced state C2 may differ from that shown in Figures 6 and 7 depending on the surfaced state when stopped.

[0065] 6(a) is the same sailing state as that of a conventional hydrofoil vessel, and is a state in which the sum of the buoyancy of the submerged parts of the hydrofoils 20 and struts 30 and the upward lift force Lu of the hydrofoils 20 is large relative to the weight of the submersible hydrofoil vessel 1. In this state, the submerged parts that receive water resistance are the submerged parts of the hydrofoils 20 and struts 30, and in the case of a fully submersible hydrofoil 20, the hydrofoil 20 is located at a depth where it is hardly affected by the water surface (free surface). Therefore, the propulsion resistance of the submersible hydrofoil vessel 1 is only the resistance of the submerged parts of the hydrofoils 20 and struts 30.

[0066] The advantages of this "Main Hull Surface Navigation N1" are the same as those of conventional hydrofoil vessels. First, because the main hull is completely surfaced, it can use internal combustion engines such as diesel engines, radio communications, radio wave equipment, and optical equipment. Furthermore, because it propels on foils, there is little propulsive resistance, enabling high-speed navigation, resulting in low fuel consumption and a wide navigation range. On the other hand, waves may hit the bottom of the vessel in rough weather, making it less weather-resistant. Furthermore, the exposed surface area above the water is large, making it less suitable for radar and stealth. Furthermore, the wake is smaller than that of a displacement-type vessel, making it less visible.

[0067] "Semi-surfaced navigation N2" as shown in Figure 6(b) is a navigation state that is performed in conventional hydrofoil vessels during the surfacing and water landing processes, in which the sum of the buoyancy of the hydrofoils 20 and struts 30 and the upward lift force Lu of the hydrofoils 20 is small compared to the weight of the submersible hydrofoil vessel 1, and the buoyancy of the main hull 10 is also utilized to navigate with more than half of the volume of the main hull 10 floating.

[0068] In this "semi-surfaced navigation N2," the parts that experience water resistance are the submerged parts of the hydrofoils 20 and struts 30 as well as the submerged parts of the main hull 10, and the propulsion resistance of the submersible hydrofoil vessel 1 is the resistance of the submerged parts of the hydrofoils 20 and struts 30 as well as the resistance of the submerged parts of the main hull 10. However, when an upward lift force Lu is applied to the main hull 10, the submerged volume is smaller than that of conventional displacement vessels or planing vessels, so frictional resistance caused by the submerged area and wave resistance and pressure resistance caused by the shape of the submerged parts are reduced.

[0069] The advantages of this "semi-surfaced navigation N2" are as follows: Because it navigates on the water, it is possible to use internal combustion engines such as diesel engines, radio communications, radio wave equipment, and optical equipment. Furthermore, the hydrofoils 20 allow the main hull 10 to be semi-surfaced, reducing the flooded volume and flooded surface area compared to navigation on a displacement vessel, thereby reducing wave-making resistance and frictional resistance. This allows for faster navigation and improved fuel efficiency than without the lift Lu provided by the hydrofoils 20. Furthermore, since the height of the above-water portion is lower than in the main hull surfaced navigation N1, and the exposed area above water is smaller, it provides slightly improved radar and stealth capabilities. Furthermore, the submerged portion prevents waves from hitting the bottom of the main hull 10 in rough weather, slightly improving weather resistance. However, the submerged portion of the main hull 10 leaves a larger wake.

[0070] The "semi-submerged navigation N3" state shown in Figure 7(a) is a navigation state rarely seen in conventional hydrofoil vessels. In this state, the sum of the buoyancy of the hydrofoils 20 and struts 30 and the upward lift force Lu of the hydrofoils 20 is small relative to the weight of the submersible hydrofoil vessel 1. Therefore, the buoyancy of the main hull 10 is also utilized to float the main hull 10. Alternatively, the weight of the submersible hydrofoil vessel 1 is added to the downward lift (sinking force) Ld of the hydrofoils 20, allowing the vessel to navigate with more than half of the volume of the main hull 10 submerged. In this state, since more than half of the main hull 10 is submerged, propulsion resistance increases, but the surface area is smaller, improving radar-resistant and stealth capabilities and increasing secrecy. However, the area penetrating the water surface is larger, leaving a larger wake.

[0071] The "Sail Surfaced Navigation N4" state shown in Figure 7(b) is what is called a "scaling" state in submarines, in which part or all of the sail 14 is surfaced. In this state, the submersible hydrofoil vessel 1 can travel by taking in and out air with the snorkel and being driven by the internal combustion engine 12a. In this state, the submersible hydrofoil vessel 1 travels with part or all of the sail 14 surfaced, utilizing the buoyancy of the submersible hydrofoil vessel 1 and the downward lift Ld (or, in some cases, the upward lift Lu) of the hydrofoils 20 relative to its own weight. In this state, only the sail 14 is surfaced, with the rest of the vessel submerged, increasing propulsion resistance. However, the smaller surfaced portion improves radar-resistant and stealth capabilities, while the smaller wake reduces visibility.

[0072] The "periscope depth navigation N5" state shown in Figure 7(c) is what a submarine would call periscope depth, where the submarine operates without snorkeling or air intake / exhaust, and operates using power from a storage battery. In this state, the sail 14 is submerged, but parts such as the periscope and communication antennas can be raised as needed. In this state, the surrounding environment can be detected using the periscope or radar, and various information can be obtained through external communications. Furthermore, the surfaced portion is significantly smaller, improving anti-radar and stealth capabilities, while the wake is smaller, significantly reducing visibility.

[0073] "Fully submerged navigation N6" as shown in Figure 7(d) is what is commonly referred to as submerged navigation in a submarine, where the vessel is propelled by power from the power storage device 12c. In this state, the vessel is fully submerged, utilizing the buoyancy of the vessel 1 and the downward lift Ld (or, in some cases, the upward lift Lu) of the hydrofoils 20 relative to its own weight. Because the vessel is fully submerged, wave-making resistance is reduced, but frictional resistance and pressure resistance increase, resulting in greater propulsion resistance. On the other hand, the absence of any floating sections ensures radar-resistant and stealth capabilities, and the vessel leaves almost no wake, significantly reducing visibility. This submersible hydrofoil vessel 1 is not intended for long-term operation at deep depths like a submarine, but rather for short-term navigation at shallow depths of a few meters to several tens of meters.

[0074] [Hydrofoil lifting, storage and separation] Furthermore, if the submersible hydrofoil vessel 1 is configured with a wing lifting mechanism 41 that changes the separation distances Sf and Sa between the main hull 10 and the hydrofoils 20, as shown in Figure 8, or if the hydrofoils 20 are stored inside or in contact with the main hull 10 and a storage and deployment mechanism 42 that deploys the stored hydrofoils 20, as shown in Figure 9, or if the vessel is configured with a wing separation mechanism 43 that separates the hydrofoils 20 from the main hull 10, as shown in Figure 10, the following advantages can be obtained.

[0075] First, the provision of the wing lifting mechanism 41 allows the hydrofoils 20 to be raised and lowered in accordance with the water depth Sd of the navigation area by changing the separation distances Sf, Sa between the main hull 10 and the hydrofoils 20 depending on whether the vessel is surfaced or submerged, thereby enabling safe navigation in shallow waters. Also, in the main hull surfaced navigation N1, the distance Su between the main hull 10 and the water surface WL can be changed, allowing for more precise responses to conditions on the water surface, such as waves.

[0076] 9, if the retraction and deployment mechanism 42 is provided, the hydrofoils 20 can be retracted during submerged navigation, thereby reducing propulsion resistance and improving propulsion efficiency. When resurfacing again, the hydrofoils 20 can be deployed for surface navigation.

[0077] 10, if the submersible hydrofoil vessel 1 is provided with a wing separation mechanism 43, the hydrofoils 20 can be separated during surfaced or submerged navigation, thereby reducing the mass of the submersible hydrofoil vessel 1 and reducing the propulsion resistance during navigation, thereby improving propulsion efficiency. Note that in this case, after separation, the hydrofoils 20 cannot be used again for navigation.

[0078] Furthermore, by changing the separation distances Sf and Sa of these hydrofoils 20, or by storing or separating them, the propulsion resistance of the submersible hydrofoil ship 1 can be reduced. Furthermore, it becomes possible to navigate in shallow waters. This ability to navigate in shallow waters is important for navigation in harbors, docking and landing operations, and landing operations. It also makes it possible to significantly reduce the volume required for storing and managing the submersible hydrofoil ship 1. Therefore, it is believed that changing the separation distances Sf and Sa will have a significant effect even if it involves moving only two locations, extended (foil-propelled state) and retracted (ship bottom).

[0079] [Submersible Hydrofoil Ship of Second Embodiment] Next, a submersible hydrofoil ship 1A of a second embodiment of the present invention will be described. As shown in Fig. 11, this submersible hydrofoil ship 1A is configured not with fully submersible hydrofoils 20, but instead with semi-submersible hydrofoils 20A as its main hydrofoils, with part of the hydrofoil protruding above the water surface during main hull surface navigation N1. The rest of the configuration is almost the same as that of the submersible hydrofoil ship 1 of the first embodiment. Note that normally, a semi-submersible hydrofoil ship is configured with a front semi-submersible hydrofoil 20A and a rear fully submersible hydrofoil 20, as in this submersible hydrofoil ship 1A, but both may be semi-submersible hydrofoils 20A, or the front and rear may be reversed.

[0080] In the semi-submersible hydrofoil vessel 1A, the semi-submersible hydrofoil 20A has stability against rolling, similar to that of the semi-submersible hydrofoil vessels of the prior art, making it easier to control. Also, compared to the fully submersible hydrofoil vessel, it can navigate in slightly shallower waters.

[0081] [Method for surfacing and sinking a submersible hydrofoil vessel] Next, we will explain the method for surfacing and sinking a submersible hydrofoil vessel in an embodiment of the present invention.This method is a method in which, in a submersible hydrofoil vessel 1, 1A composed of a main hull 10 and hydrofoils 20 arranged at a distance from the main hull 10, when the main hull 10 is raised from a stationary state to sail, the hydrofoils 20 generate an upward lift force Lu, and when the main hull 10 is submerged from a stationary state to sail, the hydrofoils 20 generate a downward lift force Ld.

[0082] In addition, in the above method, when sailing, the hydrofoils 20 generate an upward lift force Lu to raise the main hull 10, or the hydrofoils 20 generate a downward lift force Ld to lower the main hull 10, thereby causing the main hull 10 to sail in one of the following states: main hull floated state C1, semi-floated state C2, semi-submerged state C3, or fully submerged state C4.

[0083] When the submersible hydrofoil vessels 1, 1A are in the semi-afloated state C2 when stopped, they can perform semi-afloated navigation N2 because they can be in the semi-afloated state C2 while sailing without generating lift with the hydrofoils 20. The submersible hydrofoil vessels 1, 1A can perform main hull surfaced navigation N1 by generating upward lift Lu with the hydrofoils 20. The submersible hydrofoil vessels 1, 1A can also perform semi-submerged navigation N3, sail-afloated navigation N4, periscope depth navigation N5, and fully submerged navigation N6 by generating downward lift Ld with the hydrofoils 20.

[0084] Furthermore, when the submersible hydrofoil vessels 1, 1A are in the semi-submerged state C3 when stopped, they can perform semi-submerged navigation N3 because they are in the semi-submerged state C3 during navigation without generating lift with the hydrofoils 20. The submersible hydrofoil vessels 1, 1A can perform main hull surface navigation N1 and semi-submerged navigation N2 by generating upward lift Lu with the hydrofoils 20. The submersible hydrofoil vessels 1, 1A can also perform sail surface navigation N4, periscope depth navigation N5, fully submerged navigation N6, etc. by generating downward lift Ld with the hydrofoils 20.

[0085] When the submersible hydrofoil vessels 1, 1A are in a fully submerged state C4 while stopped, they can perform fully submerged navigation N6 because they can achieve the fully submerged state C4 without generating lift with the hydrofoils 20. By generating upward lift Lu with the hydrofoils 20, the submersible hydrofoil vessels 1, 1A can perform periscope depth navigation N5, sail-surfaced navigation N4, semi-submerged navigation N3, semi-surfaced navigation N2, main hull-surfaced navigation N1, etc.

[0086] According to this method for surfacing and sinking a submersible hydrofoil ship, by configuring the hydrofoils 20 to generate a downward lift Ld in addition to an upward lift Lu, the submersible hydrofoil ships 1, 1A can surfacing and sinking the main hull 10 during navigation, allowing the main hull 10 to navigate in a fully submerged state C4 or a semi-submerged state C3. Therefore, simply by widening the angle of attack of the hydrofoils 20 or the movable range of the flaps 20a, the submersible hydrofoil ships 1, 1A can perform surfaced navigation N1, N2 and submerged navigation N3 to N6.

[0087] According to this method, the submersible hydrofoil vessels 1, 1A do not need to take in or out ballast water from the main hull 10 to surface or sink, as is the case with submarines, and therefore do not need to be provided with ballast tanks. Also, since the submersible hydrofoil vessels 1, 1A do not dive to great depths like submarines, they do not need to be provided with pressure hulls, which simplifies the structure of the submersible hydrofoil vessels 1, 1A.

[0088] Furthermore, since the submersible hydrofoil vessels 1, 1A use the downward lift Ld of the hydrofoils 20 to sink the main hull 10, if the main hull 10 has enough buoyancy to remain afloat when stopped, even in the event of a malfunction of the hydrofoils 20, the submersible hydrofoil vessels 1, 1A will not sink and can safely maintain afloat.

[0089] Furthermore, when the submersible hydrofoil vessels 1, 1A are sailing on the surface, ballast water is discharged from the ballast tanks 15 provided on the main hull 10, hydrofoils 20, struts 30, etc., and when the submersible hydrofoil vessels 1, 1A are sailing submerged, ballast water is poured into the ballast tanks 15, allowing the submersible hydrofoil vessels 1, 1A to rise and fall with a smaller lift force L of the hydrofoils 20. Therefore, the hydrofoils 20 can be made smaller.

[0090] [Advantages of Submersible Hydrofoil Ships] Next, the uses of the above-mentioned submersible hydrofoil ships 1 and 1A will be explained. The advantages of the submersible hydrofoil ships 1 and 1A sailing on the surface are as follows: That is, propulsion resistance is reduced due to a reduction in flooded volume and flooded area. In addition, an internal combustion engine can be used. As a result, a long cruising distance (wide cruising range) can be achieved due to high-speed sailing and good fuel economy. Furthermore, the ability to use radio waves such as radar and communications makes it relatively easy to grasp the surrounding situation while sailing. Furthermore, the high sailing speed and smaller submerged area of ​​the ship when sailing on the surface increase the possibility of avoiding attacks from anti-submarine weapons such as anti-submarine torpedoes, anti-submarine rockets, anti-submarine missiles, and anti-underwater depth charges.

[0091] In particular, by forming the hydrofoils 20 and struts 30 of the submersible hydrofoil vessels 1 and 1A from materials such as non-magnetic aluminum alloys, titanium alloys, carbon fiber reinforced plastics, plastic materials, and stainless steel, which have lower magnetic properties than steel, it may be possible to make them compatible with magnetic fuses used in underwater attack weapons.

[0092] On the other hand, the benefits of submersible hydrofoil vessels 1 and 1A operating submerged include reduced wave resistance due to a reduced or eliminated surface volume, and a reduced wake. This significantly reduces radar and stealth capabilities and visibility. It also reduces or eliminates the effects of surface waves in rough weather. This increases the likelihood of avoiding attacks from anti-ship missiles, anti-surface missiles, anti-surface rockets, anti-aircraft missiles, naval guns, anti-aircraft guns, close-in missile defense systems (CIWS), autocannons, and machine guns. In particular, it also increases the likelihood of avoiding attacks from high-energy laser systems, which have been developed in recent years.

[0093] [Uses of Submersible Hydrofoil Ships] Next, we will explain the uses of the submersible hydrofoil ships 1, 1A that have these advantages. Here, we are considering uses for the submersible hydrofoil ships 1, 1A up to the size of hydrofoil ships of the prior art, so at this size, possible uses for military applications include unmanned surface and underwater drones, small attack boats, small rescue boats for rescuing pilots, small infiltration boats, and landing craft. In civilian applications, the only advantage of submerged navigation is for avoiding collisions in rough weather, so there may be no uses other than for underwater tourist boats.

[0094] These military boats are launched from a mother ship or base outside the enemy's search or attack range (out-range) and travel on the surface. This surface travel allows them to travel at high speeds and gain distance. Then, within the enemy's search range, where radar-resistant, stealthy, and concealed features are required, they travel submerged. This allows them to reach the target vessel, surface base, rescue area, infiltration site, landing site, etc., while increasing their stealth against radar and visual detection and their defense against surface attack weapons. For military use, the shape of the main hull 10, particularly the shape of the upper part, is preferably designed to provide radar-resistant and stealthy features like a cruise missile, and also to have a low-visibility shape and paint.

[0095] [Unmanned Surface and Underwater Drones] Next, if the submersible hydrofoil vessels 1 and 1A are unmanned surface and underwater drones, and are used for suicide missions, they will surface or submerge as necessary to enter the attack range, submerge, and collide with the target or self-destruct near the target, thereby destroying the above- or below-water parts of the target, such as surface vessels, surface bases, or surface facilities (bridge girders, piers, docks, etc.).

[0096] When used as an unmanned surface / underwater drone, the submersible hydrofoil vessels 1 and 1A have the following advantages compared to torpedoes: they can travel longer distances, are cheaper because they can use an internal combustion engine for propulsion, can carry a larger explosive load, and while sailing on the surface, can acquire information about the surroundings and target conditions by radar or visual (optical) detection or communication, and can perform surface attacks as well as underwater attacks depending on the situation. Furthermore, because they can wait on the surface or underwater, attacks can be carried out by combining various functions (e.g., surface explosion, underwater explosion, acoustic deception, chaff scattering, radio wave deception using jamming signals, decoy scattering, various attack sensors, various fuses), etc.

[0097] When the submersible hydrofoil vessels 1 and 1A are waiting within the attack range, they will wait in a state suited to the local conditions, such as floating with some parts surfaced or floating safely submerged, but in shallow waters near ports and harbors, they will wait by mooring with an anchor or sinking to the bottom. Also, when waiting for long periods of time, it may be possible to consider being able to use renewable energy such as solar energy from solar panels or energy from wave motion.

[0098] In operation, the submerged navigation is initiated when enemy radar waves are detected while the submerged navigation is in progress, or immediately before the submerged navigation reaches the effective range (approximately 1.5 km) or maximum range (approximately 5.5 km) of the target's defense system, such as the effective range (approximately 1.5 km) or maximum range (approximately 5.5 km) of the Phalanx (Close In Water Defense System: CIWS). Attacks while the submerged navigation is not necessarily effective, so attacks while the submerged navigation may be initiated without separating the hydrofoils 20.

[0099] The submersible hydrofoil vessels 1, 1A may also be equipped with detachable auxiliary fuel tanks to gain distance during surface navigation. During the attack phase, they may navigate by snorkeling or completely submerged. If the submerged state can be maintained without the hydrofoils 20, the hydrofoils 20 and struts 30 may be detached to reduce propulsion resistance. When completely submerged navigation is performed during the attack phase, propulsion means that do not require intake or exhaust are provided.

[0100] It is also possible to configure a portion of the main hull 10 as a suicide vehicle, such as a torpedo, which can be launched from the main hull 10. In this case, the suicide vehicle's propulsion system can be the same as a torpedo, as it travels only a very short distance underwater, and a short-distance propulsion system such as a rocket propulsion system can also be used. For example, a 6 km journey takes about 4 minutes and 52 seconds at 40 knots, and a 2 km journey takes about 1 minute and 40 seconds at 40 knots, so the propulsion system only needs to generate for a few minutes to 10 minutes.

[0101] In this case, the remaining main hull 10 can act as a decoy, sailing on the surface, or as an acoustic jammer to avoid detection of the separated torpedoes, or as a suicide drone equipped with a separate suicide device to crash into the target. These configurations allow for more complex attacks that combine surface and subsurface attacks.

[0102] When unmanned surface and underwater drones are used for reconnaissance and intelligence gathering, they can be submerged or surfaced as needed in the target waters to accomplish these tasks. After completing the mission, they can either be scuttled on the spot or navigated submerged and surfaced to return to their mother ship or base.

[0103] [Small craft] When the submersible hydrofoil vessels 1 and 1A are used as small rescue boats for rescuing pilots, it is preferable that they be manned and have rescue personnel on board to search for, protect, and care for the person to be rescued (pilot, etc.), as well as to observe enemy movements, be on guard, and provide protection, etc. In this case, they can quickly arrive at the scene of the pilot's distress at high speed, and rescue the pilot while waiting and traveling at low speed, either surfaced if secrecy is not required or submerged if secrecy is required, and then return by submerged and surfaced navigation after the rescue.

[0104] In addition, if it is confirmed that the pilot is uninjured or only slightly injured, and if it is better for the submersible hydrofoil vessel 1 to be as small as possible for reasons of secrecy, etc., the submersible hydrofoil vessels 1, 1A may be unmanned.In this case, it is not necessarily necessary to provide a watertight cabin in the submersible hydrofoil vessels 1, 1A, and the vessels may be equipped with diving equipment for the person to be rescued and carried thereon.The person to be rescued may don this diving equipment and board or hold onto the submersible hydrofoil vessel 1, 1A, allowing it to navigate submerged and surfaced.

[0105] Furthermore, when the submersible hydrofoil vessels 1, 1A are used as small infiltration craft, the infiltrators disembark from the submersible hydrofoil vessels 1, 1A when they reach the infiltration site submerged. After disembarking, depending on the purpose, the submersible hydrofoil vessels 1, 1A are sunk and abandoned. Alternatively, the submersible hydrofoil vessels 1, 1A can be used for return, waiting submerged, and once the infiltrators return and board, they will return to the mother ship or base by submerged navigation and then surfacing navigation. Note that, when quietness is particularly important, the engine can be stopped as necessary and the vessel can be powered by a power storage device or by human power such as rowing.

[0106] Furthermore, when submersible hydrofoil vessels 1 and 1A are used as small attack craft, they are equipped with one or more offensive weapons (torpedoes, anti-ship missiles, anti-ship rockets, anti-surface missiles, anti-surface rockets, mortars, cannons, machine guns, etc.), and as necessary, they transition to a submerged or surfaced state to attack each target with these offensive weapons. After the attack, they can either sink on the spot or return to their mother ship or base by submerged and surfaced navigation. In this case, the small attack craft may be either unmanned or manned.

[0107] [Craft] Furthermore, when the submersible hydrofoil vessels 1 and 1A are used as landing craft or landing warfare transport craft, the size of the submersible hydrofoil vessels 1 and 1A will be as large as current large hydrofoil passenger ships (for example, total length approximately 27 m, total width approximately 8.5 m, depth approximately 2.6 m, gross tonnage approximately 270 tons, passenger capacity approximately 260, cruising speed of 45 knots (approximately 83 km / h), and range approximately 450 km), and combatants, combat equipment (search equipment, attack equipment, protective equipment, etc.), combat vehicles (tanks, infantry transport vehicles, self-propelled guns, etc.), etc. will be carried within the watertight compartments of the main hull.

[0108] Since it is considered difficult for a landing craft (landing craft) or landing warfare transport craft of this size to navigate fully submerged (N6), the craft will be configured so that it navigates by snorkeling until just before landing, and then, during the landing phase, the hydrofoils 20 will be separated or retracted so that it can navigate surfaced even in shallow waters. Furthermore, the structure of the main hull 10 will be configured so that it can be beached on the shore. Also, like current landing craft, a bow ramp will be provided at the front, from which combatants and combat vehicles can disembark.

[0109] [Other Configurations] Next, several other configurations will be described. First, the propeller 12d of the submersible hydrofoil vessels 1, 1A is positioned vertically near the position of the hydrofoils 20 so that it can be used during surface navigation as well. Furthermore, when the height of the hydrofoils 20 is changed or the hydrofoils 20 are separated, the propeller 12d is configured to be able to abut against or move to the vicinity of the bottom, side, or rear of the main hull 10 so that it can be used efficiently during submerged navigation.

[0110] Furthermore, when a water jet propulsion device is used as the propulsion device 12d, the suction port must be kept submerged at all times and is therefore provided at the front or side of the hydrofoil 20, the front or side of the strut 30, or the side or bottom of the main hull 10. On the other hand, the jet port may be provided at the hydrofoil 20, the strut 30, the bottom or stern of the main hull 10, or nearby locations, and may be switched depending on the sailing conditions. The water jet propulsion device may also be configured as a unit equipped with a suction port, a pump, and a jet port, and this unit may be provided movably.

[0111] Furthermore, the hydrofoils 20 may also be arranged in three or more rows in addition to two rows in the longitudinal direction, and may also be arranged in multiple rows in the vertical direction.

[0112] [Effect] The above-mentioned submersible hydrofoil vessel and method for surfacing and submerging a submersible hydrofoil vessel make it possible to provide submersible hydrofoil vessels 1, 1A with a relatively simple configuration that are capable of high-speed navigation when waves are small and that can submerge when waves are large or secrecy is required. [Explanation of symbols]

[0113] 1 Submersible hydrofoil (fully submersible hydrofoil) 1A Submersible hydrofoil (semi-submersible hydrofoil) 10 Main Hull 11 Hull 12 Propulsion mechanism 12a Internal combustion engine 12b Power generating equipment 12c power storage device 12d thruster 13 Control Mechanism 13a rudder 13b Horizontal rudder for diving 14 Sail 14a Snorkeling 14b Electronic equipment 14c optical equipment 15 Ballast Tank 20 Hydrofoil 20a flap 20A semi-submerged hydrofoil 30 pillars 30a flap 41 Wing lifting mechanism 42 Storage and deployment mechanism 43 Wing separation mechanism C0 Fully surfaced C1 Main hull surfaced C2 Semi-floating state C3 semi-submerged state C4 Completely submerged N1 Main hull floating navigation N2 semi-surfacing navigation N3 Semi-submerged navigation N4 Sail surface navigation N5 periscope depth navigation N6 Completely submerged navigation Sa: Distance between the main hull and the rear hydrofoil Sf: Distance between the main hull and the forward hydrofoil X: longitudinal axis of the submersible hydrofoil Y - Lateral axis of the submersible hydrofoil Z: Vertical axis of the submersible hydrofoil

Claims

1. A submersible hydrofoil vessel is configured to have a main hull (10) and hydrofoils (20) arranged at a distance from the main hull (10), and is characterized in that it generates an upward lift (Lu) on the hydrofoils (20) to raise the main hull (10) from a stationary state and sail, and generates a downward lift (Ld) on the hydrofoils (20) to submerge the main hull (10) from a stationary state and sail.

2. 2. The submersible hydrofoil vessel according to claim 1, characterized in that the hydrofoils (20) generate an upward lift (Lu) to bring the main hull (10) into a main hull surfaced state (C1) or a semi-surfaced state (C2) and perform surfaced navigation (N1, N2), in which the vessel moves, and the hydrofoils (20) generate a downward lift (Ld) to bring the main hull (10) into a fully submerged state (C4) or a semi-submerged state (C3) and perform submerged navigation (N3, N4, N5, N6), in which the vessel moves.

3. 2. The submersible hydrofoil vessel according to claim 1, wherein a part or all of the hydrofoils (20) are fully submersible hydrofoils.

4. 2. The submersible hydrofoil vessel according to claim 1, wherein part or all of the hydrofoils (20) are semi-submersible hydrofoils.

5. 2. The submersible hydrofoil vessel according to claim 1, further comprising a wing lifting mechanism (41) for changing the separation distance (Sa, Sf) between the main hull (10) and the hydrofoil (20).

6. 2. The submersible hydrofoil vessel according to claim 1, further comprising a storage and deployment mechanism (42) for storing the hydrofoils (20) inside or in contact with the main hull (10) and for deploying the stored hydrofoils (20).

7. 2. The submersible hydrofoil vessel according to claim 1, further comprising a wing separation mechanism (43) for separating the hydrofoil (20) from the main hull (10).

8. A method for surfacing and submerging a submersible hydrofoil vessel (1) comprising a main hull (10) and hydrofoils (20) spaced apart from the main hull (10), characterized in that when the main hull (10) is raised from a stationary state to sail, an upward lift (Lu) is generated by the hydrofoils (20), and when the main hull (10) is submerged from a stationary state to sail, a downward lift (Ld) is generated by the hydrofoils (20).

9. 9. The method for surfacing and submerging a submersible hydrofoil vessel according to claim 8, wherein, when sailing, the hydrofoils (20) generate an upward lift (Lu) to raise the main hull (10) from a stopped state, or the hydrofoils (20) generate a downward lift (Ld) to submerge the main hull (10) from a stopped state, thereby causing the main hull (10) to sail in one of a main hull surfaced state (C1), a semi-surfaced state (C2), a semi-submerged state (C3), or a fully submerged state (C4).

10. 9. The method for surfacing and submerging a submersible hydrofoil vessel according to claim 8, wherein ballast water is discharged from the ballast tanks (15) when the main hull (10) is raised from a stopped state, and ballast water is poured into the ballast tanks (15) when the main hull (10) is submerged from a stopped state.

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