JPH0336476Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a semi-displacement type high-speed boat whose bow part rises during sailing, and particularly relates to a semi-displacement type high-speed boat equipped with pitching reduction fins.

[Conventional technology]

In general, the hull of a semi-displacement type high-speed boat is formed as shown in Figure 8 (side view), and has the advantage of being highly economical to operate and highly reliable.
On the other hand, when sailing at high speed on a sea surface with waves, the oscillation and motion acceleration of the ship become extremely large.Furthermore, the shock acceleration caused by the collision between the wave surface and the ship's hull 1 is also superimposed, making the ride uncomfortable for the crew and passengers. There is also the problem that it causes pain to people.

Figures 9a and b are graphs showing examples of measurement results of the vibration and acceleration of the above-mentioned high-speed boat in waves, respectively. Ship speed while receiving waves with wave height of 2m
It shows the hull pitching and vertical acceleration of the bow when cruising at 20 kn. As can be seen from this figure, the waveform of the vertical acceleration includes sharp peaks that indicate shocking changes, and the amount of variation in the vertical acceleration reaches three times as much as the gravitational acceleration. If such a large acceleration occurs, it will lead to deterioration of passenger comfort, damage to equipment, etc., and this can be said to be a serious drawback.

Therefore, it is conceivable to arrange fins for reducing rolling, which are used in conventional ordinary ships, under the water surface in the bow part of a half-displacement type high-speed boat to reduce pitching. FIG. 10 (side view) and FIG. 11 (plan view) show such a pitching reduction fin 2,
The case is shown in which they are provided below the water surface 3 on both sides of the bow portion of the hull 1.

In other words, in a normal ship, the energy generated during longitudinal motion of the hull is large, and the damping force and restoring force generated by the fins cannot overcome this energy, and the fins have little effect in reducing pitching. However, in high-speed boats, when sailing at high speeds, the hydrodynamic force generated by the fins increases, which may reduce pitching.

[Problem that the invention attempts to solve]

By the way, if the fins 2 for pitching reduction are attached directly to the hull 1 of a half-displacement type high-speed boat, the hull 1 will sway greatly (movement relative to the waves) under wave conditions that pose a problem for ride comfort. Then,
Since the draft is shallow, there is a high probability that the fins 2 will protrude into the air beyond the water surface 3, and in this state, the dazzling effect will not be obtained.

Further, even when the fins 2 are in the water, the fins 2 operate near the water surface 3, so it is considered that the lift force is reduced due to the influence of the free surface, and the fin effect is reduced.

The graph in Figure 12 is for the 10th and 1st ships with a length of approximately 45 m.
Figure 1 shows the relative movement of the fin attachment position to the waves when a high-speed boat like the one shown in Figure 1 is sailing at a boat speed of 30kn through irregular waves with a significant wave height of 3m and an average wave period of 7 seconds. The fins 2 are attached at the positions shown in FIGS. 10 and 11, and the submersion depth is about 1 m below the water surface. The shaded area in the figure is the state in which the fins 2 protrude into the air, and it can be seen from this figure that the fins 2 remain in the air for a long time. As described above, a half-displacement type high-speed boat has a problem in that even if the fins 2 for pitching reduction are installed, a sufficient effect cannot be obtained if the fins 2 are directly attached to the hull 1.

The present invention attempts to solve these problems by preventing the fins from being exposed above the water surface even when sailing in waves, thereby achieving a sufficient effect of reducing pitching. The purpose of the present invention is to provide a semi-displacement type high-speed boat.

[Means for solving problems]

For this reason, the semi-displacement type high-speed boat of the present invention is equipped with a pitching reduction fin on the bottom of the semi-displacement type high-speed boat, and a strut that allows the fin to protrude from the bottom of the bow section below the lowest surface of the bottom of the boat. The strut is movably attached to the hull so as to be retracted together with the fins above the lowest surface of the ship's bottom, and the strut is movably attached to the hull so that the angle of attack can be adjusted. It is characterized by having a recessed part in the bottom of the ship.

[Effect]

In the semi-displacement type high-speed boat of the present invention described above, the fins for reducing pitching are attached to the struts that protrude downward from the bottom of the bow, so that even when sailing in waves, the fins do not stay on the water surface. It is possible to always perform pitching reduction action without exposing the top.

Further, during low-speed navigation in a port or the like or when entering a dock, the strut is stored in the bottom recess along with the fin.

〔Example〕

Embodiments of the present invention will be described below with reference to drawings. Figures 1 and 2 show a semi-displacement type high-speed boat as the first embodiment of the present invention. Figure 1 is a side view thereof, and Figure 2 is its side view. FIGS. 3 and 4 show a semi-displacement high-speed boat as a second embodiment of the present invention, FIG. 3 is a side view thereof, FIG. 4 is a front view thereof, and FIGS. Figure 6 shows the sailing condition of the semi-displacement high-speed boat of the present invention in waves.
FIG. 5 is a side view thereof, and FIG. 6 is a partial side view showing the operating state of the fins.

First, a first embodiment of the present invention will be described. As shown in FIGS. 1 and 2, in the hull 11 of a half-displacement type high-speed boat, fins 12 for reducing pitching are provided at the bottom of the bow. ing.

The fins 12 are provided on a strut 14 which can protrude from the bottom of the bow along the center line of the ship below the lowest surface of the bottom of the ship, so as to project to both sides of the strut 14, respectively.

The fins 12 are driven by a hydraulic fin drive device 17 to change their angle of attack (see FIGS. 5 and 6), and a drive mechanism (not shown) is built into the strut 14.

A control signal to the hydraulic fin drive device 17 is sent from a control calculation device 16 in the bridge, and the control amount is determined based on information from a sensor 15 that detects the movement of the ship.

In addition, in the semi-displacement high-speed boat of the present invention, the first,
As shown in Figure 2, the strut 14 is connected to the fin 12.
It is movably mounted so as to be stored above the lower surface of the ship's bottom, and in this embodiment, the ship's bottom recess 2
The proximal end of the strut 14 is pivotally attached to the hull 11 via a support shaft 20 so that the strut 14 can be rotated and stored inside the hull 11.

As a drive mechanism for rotationally driving the strut 14, a hydraulic control section 19 and a hydraulic actuator 19a capable of rotationally driving the strut 14 together with the support shaft 20 using hydraulic oil from the hydraulic control section 19 are provided. There is.

Since the semi-displacement high-speed boat of the present invention is constructed as described above, when sailing in waves as shown in FIG. When the boat tilts, the bow tends to be exposed above the water surface 13 in the troughs of waves, but since the struts 14 protrude below the lowest surface of the bottom of the bow, the fins 12 are exposed above the water surface. There isn't. Then, calculate the heeling angle, heeling angular velocity, and heeling angular acceleration of the hull at that time.
Detected by a sensor 15 installed inside 1,
The measurement results are processed by the control calculation device 16 to determine the angle that the fins 12 should take.

The command for the fin angle determined in this manner is transmitted to the fin driving device 17, where hydraulic pressure for actually driving the fins is generated. The fins 12 attached to the struts 14 are driven by this oil pressure, and are brought into the state shown by reference numeral 12' in FIG.

In this way, the fins 12 have a lifting force 18 to reduce pitching without being exposed above the water surface 13.
As a result, pitching vibration is reduced and riding comfort is improved.

Figures 7a, b, and c show the pitching, center of gravity and 7 is a graph showing calculation examples of the vertical acceleration of the bow, and in FIG. 7, wavelength is plotted on the horizontal axis. From these graphs, it can be seen that by operating the fins 12, both the pitching and vertical acceleration of the hull 11 can be significantly reduced, and the riding comfort is improved.

On the other hand, when the wave conditions are calm and the hull motion is small and the riding comfort is not bad, the actuator 19a
14'' and 14'' in FIGS. 1 and 2, respectively.
As shown by 2'', it is stored in the bottom recess 21.

In this way, the fins 12 and struts 14
When the wave conditions are calm and the pitching of the hull 11 is small, it is stored above the bottom surface of the ship.
It does not increase hull resistance and is not subject to draft restrictions in shallow waters.

Next, a second embodiment of the present invention will be described. This second embodiment has the same structure as the first embodiment, and as shown in FIGS. 3 and 4, the hull 11 of a half-displacement high-speed boat is A fin 12 for reducing pitching is provided at the bottom of the bow of the boat.

The fins 12 are provided on a strut 14 which can protrude from the bottom of the bow along the center line of the ship below the lowest surface of the bottom of the ship, so as to project to both sides of the strut 14, respectively.

The fins 12 are driven by a hydraulic fin drive device 17 to change their angle of attack (see FIGS. 5 and 6), and a drive mechanism (not shown) is built into the strut 14.

A control signal to the hydraulic fin drive device 17 is sent from a control calculation device 16 in the bridge, and the control amount is determined based on information from a sensor 15 that detects the movement of the ship.

In addition, in the semi-displacement type high-speed boat according to the second embodiment of the present invention, as shown in FIGS. is attached to the hull 11 via a piston 22.

As a drive mechanism for vertically sliding the strut 14, a hydraulic drive device 23 is provided to extend and retract the piston 22.

With the above-mentioned configuration, the same effects as in the first embodiment can be obtained in this embodiment, and in addition, in this embodiment, the degree of protrusion of the strut 14 can be adjusted.
In the case where the fins 4 cannot be completely projected, there is an advantage that the pitching of the fins can be reduced by reducing the amount of the struts 14 projected so that the fins are within the draft limit.

[Effect of idea]

As detailed above, according to the semi-displacement high-speed boat of the present invention, the bottom of the high-speed boat is provided with fins for reducing pitching, and the fins move downward from the bottom of the bow section below the lowest surface of the bottom of the boat. The strut is attached to a protruding strut so that the angle of attack can be adjusted, and the strut is movably attached to the hull so as to be retracted together with the fin above the lowest surface of the bottom of the boat, and the drive mechanism and It has a simple structure with a recess in the bottom of the ship for storage, and the pitching reduction fins are not exposed above the water surface even when sailing in waves. There is an advantage in that the effect of reducing pitching of the hull of a displacement type high-speed boat can always be reliably obtained.

On the other hand, when wave conditions are calm, the fins and the struts that support them are stored above the lowest surface of the bottom of the ship, so there is no increase in hull resistance and the draft limit in shallow water is avoided. There is also the advantage of being able to sail without being affected.

[Brief explanation of the drawing]

Figures 1 and 2 show a semi-displacement high-speed boat as a first embodiment of the present invention. Figure 1 is a side view thereof, Figure 2 is a front view thereof, and Figures 3 and 4 are views of the present invention. Fig. 3 is a side view thereof, Fig. 4 is a front view thereof, and Figs. 5 and 6 show waves of the semi-displacement type high-speed boat of the present invention as a second embodiment. It shows the navigation condition at the time, and the fifth
Figure 6 is a side view of the same, Figure 6 is a partial side view showing the operating state of the fins, and Figures 7a, b, and c all show the characteristics of the high-speed boat of the present invention and the conventional high-speed boat without fins. FIG. 8 is a side view showing a conventional semi-displacement high-speed boat, FIGS. 9 a and b are graphs showing the characteristics of the above-mentioned high-speed boat, and FIGS. 10 and 11 are graphs showing the characteristics of the above-mentioned conventional high-speed boat. This shows a case in which pitching reduction fins are directly attached to a high-speed boat. Fig. 10 is a side view thereof, Fig. 11 is a front view thereof, and Fig. 12 shows the characteristics of a conventional high-speed boat equipped with the above-mentioned fins. This is a graph showing. 11... Hull, 12, 12', 12... Fin for pitch reduction, 13... Water surface, 14, 14... Strut, 15... Sensor, 16... Control calculation device, 17... Hydraulic fin drive Device, 18... Lifting force, 19... Hydraulic controller for strut and fin retraction drive, 19a... Hydraulic actuator, 20... Support shaft, 21... Bottom recess for storage, 2
2...Piston, 23...Hydraulic drive device.

Claims (1)

[Scope of Claim for Utility Model Registration] A semi-displacement type high-speed boat is equipped with pitching mitigation fins on the bottom of the boat, and the fins adjust the angle of attack to a strut that protrudes from the bottom of the bow section below the lowest surface of the bottom of the boat. The strut is attached so as to be adjustable, and the strut is movably attached to the hull so as to be retracted together with the fins above the lowest surface of the bottom of the ship. A semi-displacement high-speed boat characterized by being provided with a recess.