JPS595680Y2 - Ship propulsion performance improvement device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for improving the propulsion performance of a ship.

Figures 1 and 2 show the stern part of a normal one-shaft, one-rudder ship, and Figures 3 and 4 show the stern of a normal one-shaft, one-rudder ship, and Figures 3 and 4 show the ship shown in Figures 1 and 2, with several fins attached to the front of the propeller. This gives the incoming flow a rotational flow in the opposite direction to the rotation of the propeller, thereby canceling out the rotational flow behind the propeller and increasing the propulsion efficiency.
This figure shows a conventional ship propulsion performance improvement device designed to improve the performance of a ship, and the fins mentioned above are generally called reaction fins.

Figures 5 and 6 show a case where a ring is attached to the outside of the reaction fin to increase the strength of the reaction fin,
FIG. 7 shows the cross-sectional shape of the reaction fin and how the direction of water flow changes accordingly.

In addition, 1. Figures 3 and 5 are side views of the hull showing the stern part, Figure 2 is a sectional view taken along line II-II in Figure 1, Figure 4 is a sectional view taken along line IV-IV in Figure 3, and Figure 6 is taken along VI in Figure 5. −
7 is a Vll-VII sectional view of FIG. 4, where 1 is the hull, 1a is the bottom, 1b is the hull cross section, 2 is a diagram of the hull cross section, 3 is the propeller, 3a is a propeller boss, 4 is a rudder, 5 is an upper rudder support member, 6 is a rudder handle,
7 is a shoe piece, 7a is a cross section of the shoe piece, 8 is a propeller cap, 9 is a propeller shaft, 9a is a cross section of the propeller shaft, 10 is a stern bossing, 10a is a cross section of the stern bossing, lla is an upper stern frame, and llb is a lower part Stern frame, 12 is load waterline, 13 a, 1
3 b, 13 C, 13 d, 13e, 13
f, 13 g, 13 h are reaction fins, 1
3b' is the cross-sectional shape of the reaction fin, 14 is a ring, 15 is a water flow flowing into the reaction fin, and 16 is a water flow flowing out from the reaction fin.

The above-mentioned reaction fin device as a ship propulsion performance improvement device is used in a normal one-shaft, one-rudder ship shown in Figures 1 and 2, by providing a plurality of fins in front of the propeller to reduce the flow of water to the rear of the propeller. This improves propulsion efficiency by eliminating the rotational flow that causes loss.

3 and 4 show a case where eight reaction fins 13a to 13h are provided in front of the propeller 3, and each reaction fin 13a to 13h has one end fixed to the stern bossing 10 and the other end. is arranged in a free cantilevered manner.

The cross-sectional shape of these reaction fins 13a to 13h differs depending on the rotation direction of the propeller, but when the propeller rotates clockwise, the cross-sectional shape 13b' is as shown in FIG. 7, and due to the presence of the reaction fin 13b, ,
The water flow 15 flowing into this is the water flow 1 whose direction has changed by θ1.
It becomes 6 and flows out.

As described above, since the eight reaction fins 13a to 13h are provided radially in front of the propeller, the water flow flowing into the propeller 3 rotates in the opposite direction to the rotation direction of the propeller 3.

Therefore, by appropriately selecting the magnitude of the rotation of this water stream, it is possible to make the rotation of this water stream the same size and in the opposite direction as the rotational flow generated by the action of the propeller, resulting in a rotational flow behind the propeller. This can be done to ensure that no residue remains.

By recovering the rotational energy that has flowed to the rear of the propeller in this way, propulsion efficiency is improved.

Incidentally, the greater the number of reaction fins 13a to 13h, the better from the standpoint of creating a rotating flow, but as the number of fins increases, the resistance of the fins also increases, so it is not practical to increase the number too much.

It is also possible to attach the fin to the stern bossing 10.
It becomes more difficult as the number of fins increases.

Therefore, it is common to use a minimum of 4 reaction fins and a maximum of 10 reaction fins, and usually 6 or 8 reaction fins.

Figures 3 and 4 show reaction fins 13a to 13h fixed to the stern bossing 10 in a cantilevered manner.In such a cantilevered member, the stress is highest at the root, so the reaction fins are The structure is also thinnest at the tip and thickest at the base.

For this reason, the fins come close to each other near the base of the reaction fins, making it difficult for water to flow, and as a result, the resistance of the reaction fins increases.

In addition, each reaction fin is prone to vibration, and in order to prevent this, the structure of the reaction fin must be made extremely strong. To do this, the reaction fin must be made even thicker. It has the disadvantage of increasing resistance.

Also, from a manufacturing perspective, reaction fins 13 a to 13
A lot of work is required to secure each h to the stern bossing 10.

5 and 6 show that a ring 14 is provided on the outside of the reaction fins 13a to 13h in order to compensate for the structural defects of the reaction fins 13a to 13h, which are configured in a cantilevered manner. This is what the outer end of is fixed to.

With this structure, the cantilevered structure of the reaction fins can be eliminated, and the natural frequency of the reaction fins can be increased to avoid the generation of vibrations. However, the reaction fins 13a to 13h Since the resistance of the ring 14 is added to the resistance of the ring 14, this is not a good idea from the viewpoint of improving propulsion efficiency, and the water flow situation at the fixed portion between the reaction fins 13a to 13h and the stern bottoming 10 is hardly improved.

The stress at the root of the reaction fin is somewhat reduced by supporting the ring 14 directly from the hull, but its structure is still thickest at the root and thinnest at the tip, so that the ring 14 is attached to the hull. Even when strongly supported, the limit is to make the thickness of the reaction fin uniform from the root to the tip.

In some cases, the vertical reaction fin 1
3a and 13e may be omitted and the upper and lower stern frames lla and llb may be left as they are.

The present invention has a structural disadvantage in that the conventional reaction fins are fixed to the stern bossing, which makes the work difficult, and furthermore, the reaction fins are located close to each other in this area, which obstructs the water flow. In view of this, the purpose of the present invention is to provide a device for improving ship propulsion performance that simplifies work and allows smooth water flow by devising a fin mounting structure.

Therefore, the ship propulsion performance improvement device of the present invention has a ring having a diameter smaller than the diameter of the propeller in front of the stern propeller, and an appropriate angle of attack with respect to the water flow passing inside and outside the ring. and a plurality of fins attached radially to the ring. On the side where the propeller blades rotating in the direction of moving the ship forward move upward, the fins are cantilevered on the inside and outside of the ring. It is characterized in that the fins are provided in a cantilevered manner only on the inside of the ring on the side where the wings move downward.

Hereinafter, a ship propulsion performance improving device as an embodiment of the present invention will be explained with reference to the drawings. FIG. 8 is a side view of the stern part, FIG. 9 is a sectional view taken along line IX-IX in FIG. 8, and FIG. It is an explanatory diagram showing streamlines of water flow near the stern of a normal one-shaft, one-rudder boat, and among the symbols in FIGS. 8 to 10, the same symbols as those immediately described indicate the same parts, Also, code 3a'
are the cross sections of the propeller boss 3a, 13a', 13e',
13f', 13g', and 13h' are reaction fins provided on the outside of the ring 14, 18 is a streamline on the hull surface, 18' is a streamline at a position distant from the hull surface, and n indicates the propeller rotation direction. .

In this embodiment, eight reaction fins are provided inside the ring 14, and four half of the reaction fins are provided outside the ring 14.
Generally, the number of reaction fins provided inside the ring 14 is as follows:
Usually, the number of sheets is about 4 to 10, and the selection of the number of sheets is the same as in the case of conventional technology.

These reaction fins 13a to 13h; 13a'
, 13e', 13f, 13g', 13h' are
It is attached radially and cantileverly to both the inner and outer sides of a ring 14, which is provided in front of the propeller 3 and has a diameter smaller than that of the propeller 3. is fixed to the upper stern frame 11a, and the lower vertical reaction fin 13e' and the ring 14 are fixed to the lower stern frame llb.
Installation is being carried out.

Each reaction fin has an appropriate angle of attack with respect to the water flow passing inside and outside the ring 14.

In some cases, in addition to the above, vertical reaction fins 13a and 13e inside the ring 14 are also fixed to the stern frames 11a and 11b, respectively.

Reaction fin 13 provided on the outside of ring 14
a', 13e' to 13h' are installed in the vertical direction, and are installed radially on the side where the blades of the propeller 3, which rotates in the direction of moving the ship forward, rise, and on the side where the blades of the propeller 3 descend. Not done.

In other words, when the propeller 3 rotates clockwise, there are reaction fins 13 on the inside and outside of the ring 14 on the port side.
f, 13f, 13 g, 13g', 13 h
, 13h' are provided, and reaction fins 13b, 13c, 1 are provided only on the inside of the ring 14 on the starboard side.
3d is provided.

Reaction fin 13 provided inside ring 14
a to 13h are not fixed to the stern bossing 10,
The reaction fins 13a' to 13h' provided on the outside of the ring 14 are also cantilevered, except for the reaction fins 13a' and 13e' in the vertical direction.

As described above, in the device of the present invention, the diameter of the ring 14 is made smaller than the diameter of the propeller 3, and the reaction fins 13a to 13h, 13a' and 13h' are provided radially and cantilevered on both the inner and outer sides of the ring 14. The length of each reaction fin can be significantly reduced compared to conventional technology.

Therefore, other reaction fins 13a to 13h except for the vertical reaction fins 13a' and 13e' provided on the outer surface of the ring 14: 13f', 1
3g' and 13h' can be made sufficiently thin, so that the resistance of the fin can be made small.

In addition, the streamlines 1B and 1B' of the water flow near the stern are as shown in Figure 10, but the streamline 18' located a certain distance from the hull surface is a flow that generally rises toward the rear. Therefore, the flow on the outside of the side where the blades of propeller 3 descend is already in the form of a rotational flow in the opposite direction to the rotational flow generated in the wake of propeller 3, and even if reaction fins are installed in this part, the effect will be reduced. There are few.

Therefore, in the device of the present invention, the reaction fins in this part are omitted to reduce the resistance of the fins and simplify the work.

Furthermore, reaction fins 13a~13h, 13a'~
13h' and the ring 14 are integrally constructed, and the reaction fins 13a to 13a are provided inside the ring 14.
Since the inner end of 13h is not fixed to the stern bossing 10, it is easy to attach it to the main hull 1, and the structure of the stern bossing 10 is not only significantly simplified compared to conventional technology, but also the propeller blade This has the advantage of increasing propulsion efficiency without blocking the flow toward the roots.

As detailed above, according to the ship propulsion performance improvement device of the present invention, in front of the stern propeller, there is a ring having a diameter smaller than the diameter of the propeller, and a water flow passing inside and outside of the ring. On the other hand, the ring has a plurality of fins each having an appropriate angle of attack and is attached radially to the ring, and the fins are on the side where the blades of the propeller rotating in the direction of moving the ship forward move upward. A simple structure in which the fins are provided in a cantilevered manner on the inside and outside of the ring, and on the side where the wing moves downward, the fin is provided in a cantilevered manner only on the inside of the ring,
It has the effect of eliminating all of the conventional engineering and functional problems, significantly improving the propulsion performance of ships while reducing costs.

[Brief explanation of the drawings] Figures 1 and 2 show the stern of a normal single-axle rudder vessel.
Figure 1 is a side view, Figure 2 is a cross-sectional view taken along line II-II in Figure 1, Figures 3 and 4 show a conventional ship propulsion performance improvement device, and Figure 3 is Its side view, FIG. 4, is a cross-sectional view taken along line IV-IV in FIG.
Fig. 6 shows another example of a conventional ship propulsion performance improvement device, Fig. 5 is a side view thereof, and Fig. 6 is a view of VI-Vl in Fig. 5.
Fig. 7 is a cross-sectional view along the line, and Fig. 7 is a cross-sectional view taken along the line ■-VII of Fig.
8 and 9 show a ship propulsion performance improvement device as an embodiment of the present invention, and FIG. 8 is a side view thereof, and FIG. FIG. 10 is an explanatory diagram showing water flow near the stern of a one-shaft, one-rudder boat. 1... Hull, 1a... Bottom, 1b... Hull cross section,
3...Propeller, 3a...Propeller boss, 3a'・
... Cross section of propeller hoss, 4... Rudder, 5... Upper rudder support member, 6... Rudder handle, 7... Shoe piece, 7a
...Cross section of shoe piece, 8...Propeller cap, 9...Propeller shaft, 9a...Cross section of propeller shaft,
10... Stern bossing, 11a... Upper stern frame, 1l b... Lower stern frame, 12
...Load waterline, 13 a, 13 b, 13 C
, 13 d, 13 e, 13 f, 13 g, 1
3h...Inner reaction fin of lJ ring, 13
a', 13e', 13f, 13g', 13h'・
...Reaction fins on the outside of the ring, 14. ...Ring, 1B...Streamline on the hull surface, 18'...Streamline at a position distant from the hull surface, n...Propeller rotation direction.

Claims (1)

[Scope of utility model registration request] In front of the stern propeller, a ring having a diameter smaller than the diameter of the propeller, and a plurality of rings radially attached to the ring at appropriate angles of attack with respect to the water flow passing inside and outside the ring. On the side where the blades of the propeller that rotate in the direction of moving the ship forward move upward, the fins are provided in a cantilevered manner on the inside and outside of the ring, and the blades rotate downward. A marine vessel propulsion performance improving device, characterized in that, on the moving side, the fins are provided in a cantilevered manner only on the inside of the ring.