JPH01278896A - Water-jet pusher boat - Google Patents

Abstract

PURPOSE:To reduce the extent of drift in the whole hull at the time of turning by installing a drift restraining means, interlocking with a steering mechanism and restraining any drift in the hull due to a lateral element of water-jet reaction force, in a bow bottom part of the hull. CONSTITUTION:A fin 14 as a drift restraining means, interlocking with swing motion of a nozzle 12 and restraining any drift in the hull 11 due to a lateral element Fb of reaction force F of a water jet 13, is attached to a bow bottom part 11b of the hull 11. This fin 14 is of longitudinal platelike one along a propulsive direction of the bull 11, and it is attached retractable to the lower part from the bow bottom part 11b. In addition, it is projected to the lower part of the hull 11 at the time of the swing motion of the nozzle 12, and when this nozzle returns to its regular position, it is constituted so as to be retracted inward the hull 11. If the fin 14 advances into the water at the time of turning, turning moment is produced with the fin 14 as a fulcrum, so that any drift is thus prevented from occurring.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a water jet propulsion boat applied to high-speed boats, etc., and particularly relates to a water jet propulsion boat with improved steering function. .

(Prior Art) In general, a water jet propulsion boat uses a pump to suck in water from the bottom of the hull and ejects this water rearward from the stern as a water jet to obtain forward thrust.

Figure 16 shows the running state of a conventional waterjet LFT boat, in which the hull 1 spouts a waterjet 3 backward from the nozzle 2 at the stern 1a, and is propelled forward at high speed by its thrust. It shows. The illustrated hull 1 is relatively small, and as a phenomenon at high speed, the water surface 4 behind the hull 1 forms a flat surface roughly similar to the stern bottom surface 1b of the hull 1.

Further, unlike a propeller boat, a waterjet propulsion boat does not use a steering gear that increases thrust resistance, but is instead equipped with a steering mechanism that switches the ejection direction of the walk jet 3 from the nozzle 2 to the left or right.

FIG. 17 is a bottom view showing a water jet propulsion boat having a steering mechanism for swinging the rear end of the nozzle 2 left and right in a left-turning state. The nozzle 2 rotates to the left of the hull 1 (upward in the figure), and the reaction force F at the stern 1a of the water jet 3 is directed forward to the right (diagonally downward to the left in the figure). The forward component F of this reaction force F
At the same time as the hull 1 moves forward due to a, the rightward component “b
As a result, the stern 1a swings to the right (arrow a), and the bow section 1b
It turns towards the crab.

However, in such a conventional water jet propulsion boat, the bottom surface 1b of the hull 1 is formed flat as a whole. For this reason, for example, when the leftward component Fb of the reaction force F of the water jet 3 occurs, the overall resistance between the hull 1 and the water is small, so the entire hull 1 drifts to the left. The turning radius is correspondingly larger and the steering performance is worse. Note that this phenomenon also occurs when turning to the right.

In addition, when the bottom surface 1b of the stern 1b and the water surface 4 at the rear are in a state such as during high-speed cruising, the water depth on the bow 1b side becomes relatively large and the forward thrust is resisted. becomes larger, so the lateral flow of the hull 1 expands roughly.

(Problems to be Solved by the Invention) In conventional water jet propulsion boats, the lateral flow of the hull during turning was large, and the steering function was degraded accordingly.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a 4-tajet propulsion watercraft that can reduce the lateral flow of the entire hull during turning, thereby improving the steering function.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a hull, a pump that sucks water from the bottom of the hull, a nozzle that jets the sucked water backward from the stern as a water jet, and a water jet jet from the nozzle. In a water jet propulsion boat having a steering mechanism that switches direction from side to side, at the bottom of the bow of the hull,
The present invention is characterized in that a crossflow suppressing means is provided which works in conjunction with the steering mechanism and suppresses crossflow of the hull due to a lateral component of the water jet reaction force.

(Function) According to the present invention, when turning, the lateral flow suppression means at the bottom of the bow is activated, and the lateral flow of the hull as a whole due to the lateral component of the water jet reaction force is suppressed, and the bow quickly changes direction. Therefore, the turning radius becomes smaller, and the steering performance increases accordingly.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 J3 and FIG. 2 show the first embodiment.

The water jet propulsion boat of this embodiment sucks water from the bottom of the hull 11 with a pump (not shown), and jets the sucked water rearward as a water jet 13 through a nozzle 12 at the stern 11a. The rear end of the nozzle 12 can swing left and right, thereby forming a steering mechanism that switches the ejection direction of the water jet 12 left and right.

In this device, a fin 14 is provided at the bow bottom 11b of the hull 11 as a lateral flow prevention means that works in conjunction with the oscillation of the nozzle 12 and inhibits the lateral flow of the hull 11 due to the lateral component Fb of the reaction force F of the water jet 13. ing. That is, the fin 14 has a m-long plate shape along the propulsion direction of the hull 11, and is attached so as to be able to protrude and retract downward from the bow bottom 11b. The fins 14 are made to protrude below the hull 11 when the nozzle 12 swings, and to retract into the interior of the hull 11 when the nozzle 12 returns to its basic position (straight ahead position) by an interlocking mechanism (not shown).

According to the configuration of the first embodiment, when the propulsion direction is changed, the fin 14 of the bow bottom 11b advances into the water, and a rotational moment for turning is easily generated using the fin 14 as a fulcrum, so that lateral flow is suppressed. , the turning radius becomes smaller and steering performance can be improved.

Note that during straight running, the fins 14 rise and sink into the hull 11, so running resistance is reduced and high-speed running is not hindered in any way.

3 and 4 show a second embodiment.

In this second embodiment, the lateral flow prevention means is provided by rotating fins 15.
It is said that The rotating fin 15 is a vertically long plate-shaped member that extends in the propulsion direction of the hull 11 as in the first embodiment, but its front end has a pivoting portion 16 so that it can rotate downward from the hull 11. It is made to protrude downward from the hull 11 only when swinging. The other configurations are the same as in the first embodiment.

With this configuration of the second actual fk example as well, it is possible to suppress crossflow during turning, as in the first embodiment, and the steering function can be improved.

FIGS. 5 and 6 show a third embodiment.

In this third embodiment, in addition to the fins 15 similar to those in the second embodiment, a flap 17 as a bow flotation means is provided at the bottom of the bow 11b. The flap 17 has a horizontally elongated shape and is rotatably attached to the hull 11 via a pivot portion 18 at the front end, so that it appears and disappears into the water at the bottom of the bow 11b in synchronization with the fins 15. That is, the nozzle 12 advances into the water only when the nozzle 12 swings and turns, and lift force is applied to the bow section by the downward drifting action.

According to the third embodiment, the bow rises significantly only when the propulsion direction is changed, reducing thrust resistance when turning at high speed and more effectively suppressing crossflow.
Wear. That is, during high-speed running, as shown in FIG. 5, the water surface 19 behind the stern 11a becomes equal to the stern bottom surface 11c and the road surface. However, according to the third embodiment, this problem can be overcome by the bow floating effect, and the crossflow can be reduced. Coupled with the effect of the fin 15 as a rotational fulcrum during turning, the crossflow prevention function is enhanced and the steering function can be further improved.

7 to 9 show a fourth embodiment as a modification of the bow flotation means.

In this fourth embodiment, the water jet nozzle 1
A deflector 20 that changes the water jet direction up and down is provided on the tip side of the water jet 2, and the deflector 20 directs the water jet jet upward, and the reaction force thereof causes the bow to float. The deflector 20 has, for example, a half-cylindrical shape, and its side ends are connected by a rotating arm 21.

This deflector 20 is attached to the upper and lower ends of the nozzle 12 through the fulcrum bin 2.
2, it is integrally supported so that it can move up and down. Then, the deflector 20 is connected via a link 25 to a servo motor 24 attached to the nozzle 12 via a bracket 23,
The water jet is deflected upward (in the direction of arrow C) only when the nozzle 12 swings left and right.

With the configuration of the fourth embodiment as well, the bow floating effect can be obtained similarly to the third embodiment, and the hull rotation fulcrum fin 1
By working together with 4.15, steering performance can be improved.

10 and 11 show a fifth embodiment.

In this fifth embodiment, a lateral thrust generating mechanism 26 for generating a thrust in the opposite direction to the water jet 13 is provided at the bow bottom portion 11b of the hull 11 as a lateral flow prevention means.

This lateral thrust generating mechanism 26 is of a water jet type. That is, a pump 28 is provided at the bottom of the bow 11b to suck water through a water inlet 27, and the water sucked in by this pump 28 is selected from an auxiliary nozzle 31 on the side of the bow via an automatic valve 29 and a three-way switching valve 3o. It is designed to eject sideways as an auxiliary water jet 1-32.

When the propulsion direction is changed, the automatic valve 29 is opened in conjunction with the swing of the stern nozzle 12, and the three-way switching valve 30 opens to the side of the auxiliary nozzle 31 facing opposite to the water jet 13. Then, the water flow from the pump 28 is ejected from the auxiliary nozzle 31 to the side of the hull as an auxiliary water jet 32.
A thrust (arrow d) opposite to the lateral component Fb of the reaction force F of the water jet 13 at the stern 11a is generated on the bow side.

Note that as a water source for the auxiliary water jet 32, pressure water from the main pump for generating the water jet 13 for main propulsion or cold water from the main engine may be used.

According to the configuration of the fifth embodiment, when the propulsion direction is changed, the lateral component Fb of the reaction force of the oak jet 13 and the reaction force of the auxiliary water jet 32 become a couple, and the rotational moment for turning can be easily generated. This can further improve the ability to prevent cross-flow of the ship and further improve the steering performance.

FIGS. 12 and 13 show a sixth embodiment.

In this sixth embodiment, a side thruster 33 constitutes a lateral thrust generating mechanism as a lateral flow suppressing means.

That is, a pair of projecting guides 34 extending in the longitudinal direction are provided in parallel on both sides of the bottom of the hull 11, and a side thruster 33 is attached to each of the projecting guides 34 on the bow side. The side thruster 33 consists of a horizontal screw, and the one facing opposite to the water jet 13 is driven when the propulsion direction is changed.
By generating a lateral thrust similar to the fifth embodiment, lateral flow is suppressed.

With such a configuration as well, a couple can be generated at the bow and stern, and the same effect as in the fifth embodiment can be achieved.

FIGS. 14 and 15 show a seventh embodiment.

In this embodiment, in addition to the configuration of the sixth embodiment, a flap 35 for the bow 7 is provided. Similar to the third embodiment, this flap 35 extends into the water when the nozzle 12 is necked, and generates lift at the bow.

According to this seventh embodiment, the hull 11
Since the frontal resistance can be reduced, the crossflow prevention function is enhanced, and the steering function becomes even more excellent, especially at high speeds.

It should be noted that each of the above embodiments does not need to be used independently, and can be implemented as a configuration in which they are combined arbitrarily.

[Effects of the Invention] As described above, according to the present invention, by providing the crossflow prevention means at the bow of the ship, it is possible to reduce the turning radius to enable quick changes in the direction of travel, and to improve water jet propulsion. You will be able to improve your ability to steer a boat.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the first embodiment of the present invention, FIG. 2 is a bottom view of FIG. 1, FIG. 3 is a side view showing the second embodiment, and FIG.
The figure is a bottom view of FIG. 3, FIG. 5 is a side view showing the third embodiment, FIG. 6 is a bottom view of FIG. 5, FIG. 7 is a plan view showing the fourth embodiment, and FIG. Fig. 7 is a right side view, Fig. 9 is a sectional view taken along the rX-IX line in Fig. 8, Fig. 10 is a side view partially showing the fifth embodiment in section, and Fig. 11 is a bottom view of the tenth embodiment Figure 12 shows the 6th fruit/l! 13 is a sectional view taken along the line ■-■ in FIG. 12, FIG. 14 is a side view showing the seventh embodiment, FIG. 15 is a sectional view taken along the line W-n in FIG. FIG. 16 is a side view showing a conventional example, and FIG. 17 is a bottom view of FIG. 16. 11...Hull, 12...Nozzle, 13...Water jet, 14.15...Fin (lateral flow suppression means), 26.33...Sideward thrust generation mechanism (lateral flow suppression means). Figure 1 Figure 2 $9 Figure $6 Figure 1000 Concave Figure 12 Figure $14

Claims (1)

[Claims] Water jet propulsion has a hull, a pump that sucks water from the bottom of the hull, a nozzle that jets the sucked water backward from the stern as a water jet, and a steering mechanism that switches the direction of water jet jetting from this nozzle to the left or right. 1. A water jet propulsion watercraft, characterized in that a lateral current suppression means is provided at the bottom of the bow of the hull in conjunction with the steering mechanism to suppress lateral flow of the hull due to a lateral component of a water jet reaction force.