JPH0333595Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a turning motion control device for a ship using a reaction fin that is installed to improve the propulsion performance of a ship.

Traditionally, in order to improve the propulsion performance of ships,
A reaction fin is installed at the stern.

The reaction fin is as shown in Figure 3.
It consists of a large number of fin blades 5 that protrude radially from a boss surrounding the propeller shaft in front of the screw propeller 2, and a ring strut 6 that supports the tips of the fin blades 5. The angle of attack of the fin blades 5 is set so as to generate a rotational flow in the opposite direction to the rotational flow 4 (see FIG. 2) generated as the propeller 2 rotates.

Therefore, the rotational flow 4 generated by the propeller 2 is canceled by the rotational flow given in advance by the reaction fin, so the propeller 2 accelerates the water flow only backwards without leaving any rotational flow 4 (see Figure 3). ), its propulsion performance improves.

By the way, in general, when the hull 1 with a forward speed is stopped or moved further backward, the propeller 2
By reversing the propeller 2 or reversing the blade angle of the propeller 2, a backward thrust is generated in the propeller 2. However, it is well known that in such a propeller reversal state, the hull 1 usually turns. ing.

The cause of this turning is the lateral force F generated near the stern due to propeller reversal as shown in Figure 1. It varies greatly depending on the condition.

On the other hand, when the propeller is in reverse rotation, the force generated by the rudder 3 is much smaller than the lateral force F, even if the steering angle is large.

As a result, the turning movement after the propeller is reversed becomes almost uncontrollable even with the rudder 3, which is the only navigation device for a normal ship.

Figures 4 a to c show the above-mentioned unmaneuverable state in a self-propelled model ship. In the figures, the solid line indicates the case of a vessel not equipped with a reaction fin, and the broken line indicates the case of a vessel equipped with a reaction fin. are shown respectively.

Figure 4a shows the turning angular velocity r, and Figure 4b shows the turning angle Ψ.
FIG. 4c is a graph showing the trajectory of the center of gravity, and the values on the vertical and horizontal axes of FIG. 4c are the ratio of the amount of movement of the ship to the ship's length.

From FIG. 4c showing the center of gravity locus, it can be seen that in a ship not equipped with a reaction fin, the ship turns significantly to the right during the stopping movement due to propeller reversal, and continues to turn to the right during the backward movement. On the other hand, in the case of a vessel equipped with a reaction fin, it turns to the left during stopping motion and travels almost straight during backward motion.

As described above, although the directional stability of the vessel is considerably improved by equipping the vessel with a reaction fin, the inability to control the vessel after the propeller is reversed remains unresolved.

Although it is one aspect of various vessel maneuvering situations, the existence of such an uncontrollable state is unfavorable from the viewpoint of navigation safety and air traffic control.

In view of the above circumstances, the present invention provides a turning motion control device for a ship that can control the turning of the ship by controlling the lateral force generated near the stern when the propeller is reversed. The purpose is to

For this reason, the ship turning motion control device of the present invention is
In front of the screw propeller at the stern, a plurality of fins protrudes radially from a boss that surrounds the propeller shaft and is supported at the tip by a ring strut.In order to adjust the angle of attack of the fins to control the turning movement, The indicator, the fin angle of attack changing mechanism, the pressure detection sensors attached to the port and starboard sides of the stern below the water surface, the detection signal from the pressure detection sensor, and the signal from the turning direction indicator, The present invention is characterized in that the fin angle of attack changing mechanism is provided with a fin angle of attack control section that outputs an angle of attack command signal.

Hereinafter, a turning motion control device for a ship as an embodiment of the present invention will be explained with reference to the drawings.
The figure is a perspective view schematically showing the overall configuration, FIG. 6 is a perspective view showing the fin angle of attack changing mechanism, FIG. 7 is a view taken from the - arrow in FIG. 6, and FIG. 8 is a state of adjusting the fin angle of attack. FIG.

As shown in FIG. 5, in front of the screw propeller 2 at the stern, a plurality of fin blades 15 radially protrude from a boss 7 surrounding the propeller shaft, and the tips of the fin blades 15 are connected to a ring strut 16. , respectively, via bearings 17.

A fin blade attack angle changing mechanism 18 is provided at the base of the fin blade 15, so that the fin blade 15 can be rotated around an axis connecting the base and the bearing 17.

In this embodiment, the angle of attack changing mechanism 18, as shown in FIGS. 6 and 7, drives a worm wheel 21 attached to the base of the fin blade 15, a worm 20 that engages with the worm wheel 21, and a worm 20. Drive motor 22 inside the main hull
is provided.

Further, pressure detection sensors 19, 19 are provided on the port and starboard sides of the stern below the waterline.

As shown in FIG. 8, upon receiving the detection signals from the pressure detection sensors 19, 19 and the signal from the turning direction instruction section 24 which outputs the operator's intention to maneuver the vessel, the motor controller 26 is instructed to command the fin angle of attack. A fin angle of attack control section 25 is provided that outputs a signal.

Note that a motor controller 26 is provided for each fin blade 15 and is adapted to control the drive motor 22.

With the above-described configuration, the angle of attack of the fin blade 15 can be changed freely, so that the strength of the rotational flow component of the water flow passing through the fin blade 15 and its rotation direction can be adjusted freely.

Therefore, propeller 2 such as when a ship moves forward
During forward rotation, if the angle of attack of each fin blade 15 is adjusted to generate a rotational flow that cancels out the rotational flow of the propeller 2, the rotational flow will cancel out and the propulsion performance will improve.

On the other hand, when the propeller 2 is reversed, such as when the ship is stopped or moving astern, the angle of attack of the fin blade 15 can be adjusted to generate a rotational flow in the direction that cancels the rotational flow caused by the reversal of the propeller 2. As a result, the lateral force F (first
(see figure) is prevented from occurring, the turning movement caused by the reverse rotation of the propeller 2 is eliminated, and the directional stability of the ship is improved.

When adjusting the angle of attack of the fin blade 15 described above, pressure corresponding to the lateral force F near the stern is detected by the pressure detection sensors 19, 19, and the fin angle of attack control section 25 adjusts this signal and the turning direction. Since the angle-of-attack command signal for each fin blade 15 is output based on the signal from the instruction section 24, the blade angle of the fin blade 15 can be automatically adjusted for turning motion control.

In addition, when the propeller 2 is reversed, if you want to stop and move backward while turning more strongly, the propeller 2
In order to further promote the reverse rotation flow, the fin blade 1
By adjusting the angle of attack 5 to promote the generation of lateral force F near the stern, the required turning motion can be obtained by reversing the propeller 2.

As described in detail above, according to the turning motion control device for a ship of the present invention, a plurality of fins protrude radially from the boss surrounding the propeller shaft in front of the screw propeller at the stern and whose tips are supported by the ring strut. In order to adjust the angle of attack of the fin for turning motion control, it is equipped with a turning direction indicator, a fin angle of attack changing mechanism, and a pressure detection sensor attached to each of the starboard and starboard sides under the water surface in the stern section. It has an extremely simple configuration that includes a fin angle of attack control section that receives a detection signal from the detection sensor and a signal from the turning direction instruction section and outputs an angle of attack command signal to the fin angle of attack changing mechanism. The Yonghuin's angle of attack can now be automatically adjusted according to the operator's intention to control turning. In other words, in addition to improving propulsion efficiency by canceling out the propeller rotational flow when the ship is moving forward, it also controls the turning motion by adjusting the lateral force generated on the ship when the propeller reverses, such as when stopping or going astern. This makes it possible to control the ship even when the propeller is reversed, thereby eliminating the uncontrollable state of the ship, which has the advantage of improving the navigation safety of the ship.

[Brief explanation of the drawing]

Figures 1 and 2 show the stern of a ship not equipped with a reaction fin. Figure 1 is a perspective view showing when the propeller is rotating in reverse, Figure 2 is a perspective view showing when the propeller is rotating forward, and Figure 3 is a perspective view showing when the propeller is rotating forward. The figure is a perspective view showing the stern of a vessel equipped with a conventional reaction fin.
Figures a to c are graphs showing a state in which a self-propelled model ship is unable to maneuver, and Figures 5 to 8 show a turning motion control device for a ship as an embodiment of the present invention. Perspective view schematically showing the overall configuration, No. 6
7 is a perspective view showing the fin angle of attack changing mechanism, FIG. 7 is a view taken along the - arrow in FIG. 6, and FIG. 8 is a block diagram showing how the fin angle of attack is adjusted. 1... Main hull, 2... Propeller, 3... Rudder, 4
...Propeller rotation flow, 7...Boss, 15...Fin blade, 16...Ring strut, 17...
... bearing, 18 ... fin blade angle of attack changing mechanism,
19...Pressure detection sensor, 20...Warm, 2
1... Worm wheel, 22... Drive motor,
23...Pressure conversion section, 24...Turning direction instruction section,
25...fin angle of attack control section, 26...motor controller.

Claims (1)

[Scope of utility model registration request] In front of the screw propeller at the stern, a plurality of fins protrude radially from a boss surrounding the propeller shaft and have their tips supported by a ring strut.In order to adjust the angle of attack of the fins to control the turning movement,
A turning direction indicating section, a fin angle of attack changing mechanism, a pressure detection sensor attached to each of the port and starboard sides under the water surface of the stern, and a detection signal from the pressure detection sensor and a signal from the above turning direction indicating section are received. A turning motion control device for a ship, characterized in that a fin angle of attack control section is provided for outputting an angle of attack command signal to the fin angle of attack changing mechanism.