JPH07267176A - Hull for ship with hydrofoil - Google Patents

Abstract

PURPOSE:To prevent lowering of a pusher by a method wherein a ship bottom is divided into a front ship bottom positioned in a deep position and a rear ship bottom positioned in a shallow position by a difference in level, and protrusion parts on the gunwale side the inner surfaces of which are vertical are formed on the two gunwales of a ship bottom throughout a range extending from a position in front of the difference in level to the rear end of a ship hull. CONSTITUTION:A ship bottom is divided into two parts of the one being a front ship bottom 2 positioned in a deep position and the other being a rear ship bottom 3 positioned in a shallow position by a difference in level 4. Protrusion parts 8 on the gunwale side each starting from the intermediate of the front ship bottom 2 to the rearmost end of a ship hull 1 are formed in succession on both gunwales of the ship bottom. A sectional shape is an acute state, and protruded downward in a state to incline toward the inside so that an inner surface 8a is extended almost vertical. A ship bottom protrusion 9 is formed in a moderate V-shape in cross section and protruded in such a shape that the protrusion part starts from the intermediate part of the rear ship bottom 3 to the rear end part of the ship body 1, and depth and width are gradually increased toward the rear end of the ship hull 1 and at a last end, the protrusion occupies almost the whole width of the rear ship bottom 3 and a lower end is extended to a position deeper than the protrusion part 8 on the gunwale side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the shape of a hull with a hydrofoil in which a hull and all-submersible hydrofoils generate lift to travel.

[0002]

2. Description of the Related Art Among hydrofoil-equipped vessels, there are known hydrofoil-equipped vessels that generate lift to support a part of the weight of the hull by submerged hydrofoil, and project downward on both sides of the bottom of the vessel. It has been proposed that a catamaran-like ship with the above-mentioned body part is used, in which air is introduced into the lower surface of the hull surrounded by the bottom and the body part, and lift force is also generated by this air.

However, in the conventional catamaran of this type, the body has a V-shaped cross-section and the inner surface is inclined, and when the vessel is sailed with the bow raised, it hits the inner surface of the body. The water flow is bounced back toward the center as shown in FIG. 4, and the scattered water and air are mixed to generate a water flow in which a large amount of bubbles are mixed. In FIG. 4, 1 is a hull, 1a is a ship bottom, 1b is a body, 1c is an inner surface thereof, and arrows indicate water flows.

For this reason, the propulsion device arranged at the center of the rear part of the hull operates in a water flow containing air bubbles, which reduces efficiency and makes it impossible to obtain sufficient propulsive force. . This problem applies not only to simple catamaran ships, but also to ship-bottomed ships having a stepped structure with a stepped front as shown in FIG. 8 of Japanese Patent Application No. 4-269722. Occur in.

When a hydrofoil is attached to a catamaran having a simple shape without steps, the hydrofoil is generally attached directly from the inner side surfaces of both sides or the hydrofoil is inserted into a groove vertically formed on the side surfaces. We have adopted a structure that fits the columns of. However, in the former case, the submersible depth of the hydrofoil becomes shallower, and the risk of exposure to the air becomes higher.In the latter case, the angle of attack of the hydrofoil cannot be adjusted because the strut cannot be a movable structure, and the flap must be used. Together with this, the mechanism becomes complicated and is not suitable for small ships. In addition, there are many problems such as the structure of the upper part of the hydrofoil becoming complicated and the resistance of the supporting column increasing.

[0006]

The present invention has been made for the purpose of solving these problems and obtaining a hull having a shape suitable for a hydrofoil-equipped ship.

[0007]

In order to achieve the above object, in the first invention, the bottom is divided into two parts, a front bottom at a deep position and a rear bottom at a shallow position by a step. In addition to the shape, a port side projection having an inner surface that is substantially vertical and has a cross-sectional shape that projects downward in an acute angle is formed continuously on both sides of the ship bottom from the front of the step to the rear end of the hull.

Further, in the above-mentioned hull, a deeper and wider portion is formed toward the rear end of the hull, and at the rearmost end, a V-shaped bottom protuberance having a V-shaped cross section is formed near the rear of the rear bottom. ing.

According to the second aspect of the present invention, the trunk portions projecting downward are formed on both sides of the ship bottom, and steps are formed on the inner surfaces of the trunk portions so that the distance between the trunk portions becomes wider at the rear. Along with this step, a column that supports the hydrofoil is placed immediately after this step.

[0010]

In the first aspect of the invention, since the inner surface of the port side protrusion is almost vertical and the water flow does not bounce toward the center of the hull even if it hits this, the splashed water and the air introduced into the lower surface of the hull are mixed. As a result, a water stream containing a large amount of bubbles is less likely to occur. Therefore, the propulsion unit at the rear of the hull can operate in a water flow with few bubbles, and it becomes easy to obtain a sufficient propulsion force. Further, in the case where the ship bottom projection having a V-shaped cross section is formed, this has the effect of pushing away the water flow in the upper layer where air introduced into the lower surface of the hull easily mixes, so that bubbles in the water flow reaching the propulsion device are exerted. Can be further reduced.

According to the second aspect of the present invention, since the supporting column is arranged at a position immediately after the step where the water flow does not hit, the resistance of the supporting column and its supporting mechanism or drive mechanism is reduced, and the hydrofoil device is made smaller and lighter. Therefore, it becomes easy to arrange the hydrofoil at an appropriate depth.

[0012]

[Embodiment 1] Next, an embodiment of the first invention will be described. FIG. 1 is a bottom view, FIG. 2 is a side view and a view showing a contour in a portion of chain lines A to D.

In FIG. 1, 1 is a hull, 2 is a front ship bottom,
3 is a rear bottom, 4 is a step, and the bottom is due to the step 4, the front bottom 2 at a deep position and the rear bottom 3 at a shallow position.
The shape is divided into two parts. 5 is a hydrofoil, 6 is its support, 6a is a rear ship bottom 3 behind the step 4.
The hydrofoil 5 is arranged on the hull center line at a position deeper than the rear end of the front bottom 2 of the ship. Reference numeral 7 denotes a propulsion device provided at the rear of the hull 1.

Reference numeral 8 indicates a portion in front of the step 4, that is, the front ship bottom 2
It is a port side projection that starts from the middle part of the ship and continues to both sides of the ship bottom up to the last end of the hull 1. Its cross-sectional shape is an acute angle, and the inner surface 8a is directed inward so that it is almost vertical. It projects downwards in a tilted state. Reference numeral 9 denotes a bottom protrusion that starts from the middle portion of the rear bottom 3 and extends to the rear end of the hull 1, and has a gentle V-shaped cross section.
It is deeper and wider as it approaches the rear end of the hull 1, and occupies almost the entire width of the rear ship bottom 3 at the rear end, and the lower end of the hull 1 is formed so as to reach a position deeper than the side projection 8.

The hull 1 of this embodiment is constructed as described above, and when the boat sails with the bow raised, the water flow hits the inner surface 8a of the port side protrusion 8 substantially in parallel, so that it is indicated by an arrow in FIG. As described above, it does not bounce back at a large angle, but comes out rearward as it is along the inner surface 8a, and the amount of scattering toward the center is significantly reduced. Therefore, a water flow containing a large amount of bubbles is unlikely to be generated, which is the rear propulsion device 7.
The efficiency will not be reduced by reaching to.

Further, since the ship bottom protrusion 9 is formed on the rear ship bottom 3, the water flow in the upper layer, into which the air introduced into the lower surface of the hull 1 easily mixes, is pushed to the left and right,
There are fewer bubbles in the water stream reaching the propeller 7. Therefore, it becomes easy to sufficiently exhibit the performance of the propulsion device 7.

Incidentally, in a hydrofoil system in which a part of the weight of the hull is supported by the lift of the hydrofoil during navigation, the front part of the hull is lifted and the water contact area of the planing surface of the hull is reduced. Power tends to decrease. However, the port side projection 8 in this embodiment also has an action of generating buoyancy when coming into contact with water to secure a necessary restoring force, which is also effective in increasing the stability of the hull.

[0018]

[Embodiment 2] Next, an embodiment of the second invention will be described. 5 is a bottom view and FIG. 6 is a sectional view. In FIG. 6, the upper structure of the hull and the propulsion device are omitted.

The hull 1 of this embodiment is provided with a simple bottom 11 having no step, and both sides of the bottom 11 are projected downward to form two trunks 12 in parallel. There is. Reference numeral 13 denotes a step formed on the inner surface of each body portion 12, and the inner surface of the body portion 12 has a shape divided into a front inner surface 12F and a rear inner surface 12R, and between the rear inner surfaces 12R and 12R. The spacing is wider than the spacing between the front inner surfaces 12F and 12F. Reference numeral 14 denotes a hydrofoil, and 15 denotes two columns that support the hydrofoil 14. Each column 15 is attached to a portion of the rear inner surface 12R immediately after the step 13, and the hydrofoil 14 is supported at the tip thereof. There is.

The column 15 is rotated in the front-rear direction by a drive mechanism (not shown) to control the angle of attack, and is also rotated rearward as shown by the chain line in FIG. ing.

The hull 1 of this embodiment has the structure as described above, and as shown in FIG. 7, the water flow W flowing along the front inner surface 12F during traveling is directed to the rear as it is even after passing through the step 13. Flow, and it does not directly hit the base of the column 15 in the step 13. Therefore, no resistance is generated by the support column 15 in the step 13 and its mounting mechanism, and the resistance of the entire hydrofoil device is reduced. In addition, the load of the drive mechanism of the column 15 is reduced accordingly, the drive actuator is small, and the resistance is not increased, so that the pivot center of the column 15 can be arranged near the bottom of the ship bottom. Therefore, it is easy to reduce the size and weight of the hydrofoil device.

The second invention is not limited to the hull having the shape as in this embodiment. For example, as in the first embodiment, a hull having a stepped portion or a front hull It can be applied to other shapes such as a three-body type.

[0023]

As is apparent from the above description, according to the first aspect of the present invention, in a ship having a step on the bottom of the ship, a port side projection whose inner surface is substantially vertical is continuously formed from the front of the step to the rear end of the hull. Since it is formed on the port side, the water that has hit the port side projection and the air that has been introduced to the underside of the hull are not mixed, and a water flow containing a large amount of bubbles does not occur, preventing the efficiency of the thruster from decreasing. . Further, in the case where the ship bottom projection having a V-shaped cross section is formed, the water flow in the upper layer where air is easily mixed is pushed away, so that the bubbles in the water flow reaching the propulsion device can be further reduced and a sufficient propulsive force can be obtained. Is effective in generating.

According to the second aspect of the present invention, a trunk portion projecting downward is formed on both sides of the bottom of the ship, and a step is formed on the inner surface of the trunk portion so that the distance between the trunk portions becomes wider at the rear. Immediately after, the support columns for supporting the hydrofoil are arranged, so that the support column and its supporting mechanism or drive mechanism are not hit by the water flow, and the resistance is reduced. Therefore, the hydrofoil device is effectively reduced in size and weight, and the hydrofoil can be easily arranged at an appropriate depth.

[Brief description of drawings]

FIG. 1 is a bottom view of an embodiment of the first invention.

FIG. 2 is a side view of the embodiment and a diagram showing a contour in a portion of chain lines A to D.

FIG. 3 is an operation explanatory diagram of the embodiment.

FIG. 4 is an operation explanatory diagram of a conventional example.

FIG. 5 is a bottom view of an embodiment of the second invention.

FIG. 6 is a schematic sectional view of the embodiment.

FIG. 7 is an operation explanatory diagram of the embodiment.

[Explanation of symbols]

 1 Hull 2 Front Ship Bottom 3 Rear Ship Bottom 4 Step 5 Hydrofoil 7 Propulsion Device 8 Side Protrusion 8a Inner Surface 9 Ship Bottom Projection 11 Ship Bottom 12 Body 12F Front Inner Surface 12R Rear Inner Surface 13 Step 14 Hydrofoil 15 Strut

Claims (3)

[Claims] 1. A hull of a ship with hydrofoils, which has hydrofoils on its bottom, and which runs while generating lift to support a part of the weight of the hull by the hydrofoils, the front bottom of which is deep in the bottom. And the shallow part of the aft ship bottom is divided into two parts by a step, and the port side projection with an acute-angled cross-sectional shape that projects downward at an angle at which the inner surface is almost vertical from the front of the step. A hull of a ship with hydrofoils characterized by being formed continuously on both sides of the bottom of the ship to the rear end of the hull. 2. A bottom protrusion having a V-shaped cross section which is deeper and wider as it approaches the rear end of the hull and reaches a position deeper than the port side protrusion at the rear end is formed at the rear of the rear bottom. The hull of the ship with hydrofoil described. 3. A hull of a ship with hydrofoils, which is equipped with hydrofoils on the bottom of the ship and which runs while generating a lifting force for supporting a part of the weight of the hull by the hydrofoils, and which projects downward on both sides of the bottom of the ship. Along with the formation of the torso, a step is formed on the inner surface of each torso so that the distance between the two torso becomes wider at the rear, and immediately after this step, a column for supporting the hydrofoil is arranged. Characteristic hull of a ship with hydrofoil.