JPH0640394A - Propeller strut device of boat - Google Patents

Abstract

PURPOSE:To prevent speed from decreasing caused by the increase of propulsion resistance and Karman's vortex street from being generated by providing a current plate capable of turning by 360 deg. around a column. CONSTITUTION:A rudder blade 12 is parallel to the direction of travel in going astern and straight. However, the flow of water having deflection angle alpha is generated from right back in relation to a current plate 13. In this case, since the current plate 13 becomes in the reversed state from the state where it advances along the flow of water, and streamed in the direction of the flow of water, lateral force is not generated to the current plate 13, thereby a hull 1 goes straight and astern. In right turning while going astern, since the flow of water having deflection anglealpha generated from a propeller 9 comes in contact with the current plate 13, and the current plate 13 is streamed thereby, lateral force FS is not generated to the current plate 13. Accordingly, right turning can be performed by lateral force FR generated on the rudder 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft bracket device which is provided in front of a propeller so as to project below the bottom of a ship so as to support the propeller shaft.

[0002]

2. Description of the Related Art In FIG. 12, a shaft bracket (41) is mounted in front of a propeller (9) so as to project below the ship bottom (2) so as to support the propeller shaft (8). The shaft bracket (41) is integrally formed with a flange (5) fixed to the ship bottom (2), a plate portion (42) hanging below the flange (5), and a lower end of the plate portion (42). The propeller shaft penetrates through and is supported by the bearing portion (7).

The plate portion (42) serves as a straightening plate for reducing resistance when the hull advances, and has a streamline cross section and is parallel to the centerline of the hull centerline. It is provided.

Further, Japanese Utility Model Laid-Open No. 61-37100 discloses that the plate portion (42) is fixed by providing a tricing angle for correcting the reaction caused by the rotation of the propeller (12). .

[0005]

[Problems to be Solved by the Invention] When the water flow hits the plate portion (42) with declination (α, β) during navigation of the ship, the plate portion (42)
Lifting force is generated on. This lift acts to move the hull in the portion provided with the plate (42) in the lateral direction. This lift force (hereinafter referred to as lateral force) reduces the turning force of the rudder blade when moving forward, and causes an extreme imbalance in the left and right turning forces when moving backward. That is, when viewed from the rear of the hull, the ship in which the propeller (9) rotates to the right (in this specification,
In the description of propeller right rotation), there is a problem that a reverse left turn is possible, but a reverse right turn is almost impossible. This point is the same as in the invention of Japanese Utility Model Laid-Open No. 61-37100, which is effective when the propeller water flow hits the plate portion in the backward and straight traveling, but in the other cases, there is a disadvantage that lateral force is generated. there were.

The operation of the prior art shown in FIG. 12 will now be described with reference to FIG. 13 and subsequent figures. FIG. 13 shows a forward left turn, in which the rudder blade (12) behind the propeller is turned to make a left turn. When the turning is performed, a lateral force F _R is generated on the rudder blade (12) in the starboard direction, but since the downward flow of water hits the plate portion (42) at an angle β, a lateral force F _S is generated in the port side direction. However, in general, the lateral force F _R
Is larger than the lateral force F _S , it is possible to turn with the remaining lateral force obtained by subtracting F _S from F _R , but a large lateral force F _R is required for that, and therefore the rudder blade Has to be increased.

FIG. 14 shows a reverse left turn, and in reverse, the water flow F _R pushed out from the propeller (9) because the propeller (9) is ahead (upstream) of the plate portion (42). However, since the propeller (9) is affected by the rotation direction of the propeller (9) and hits the plate portion (42) at an angle of deviation α, a lateral force F _S due to the deflected water flow is generated in the left rudder direction. However, this lateral force F _S
Is in the same direction as the lateral force F _R generated on the rudder blade (12), so that the vehicle can turn with a strong lateral force that is the sum of F _R and F _S.

On the other hand, in the case of a reverse right turn as shown in FIG. 15, this lateral force F _S cancels each other out in the direction opposite to the lateral force F _R. As described above, in reverse, the lateral force F _R is small, so that F _S and F _R are substantially balanced, and the lateral force is almost eliminated. Therefore, it is almost impossible to make a right turn. It has been regarded as an issue.

That is, a first object of the present invention is to reduce the required area of the rudder plate by preventing the turning force of the rudder plate from decreasing during forward turning. The reduction in the area of the rudder blade results in a reduction in propulsion resistance and can increase the ship speed.

A second object of the present invention is to eliminate the right-left turning force and the left-hand turning force by eliminating the left-right imbalance of the turning force caused by the lateral force that is always generated in the port portion at the time of reverse turning. Is to equalize.

As described above, a common problem in solving the first problem and the second problem is that lateral force is not generated in the shaft bracket plate portion. For that purpose, it is effective to make the portion cylindrical so that lateral force is not generated regardless of the direction of water flow. However, in the case of a cylinder, in addition to a large propulsion resistance, Karman vortices are generated, which may induce hull vibration. So 36 around the cylinder
The present invention intends to prevent the generation of Karman vortices as well as to prevent the speed decrease due to the increase of the propulsion resistance by providing the straightening plate which can rotate 0 °.

[0012]

In order to solve the above-mentioned problems, according to the present invention, in a shaft bracket having a propeller bearing for supporting a propeller shaft at a lower end of a columnar part projecting downward from a ship bottom, the columnar part is provided. The present invention is characterized in that a straightening plate that can rotate 360 degrees is rotatably fitted to the water flow according to the traveling direction of the hull.

[0013]

According to the above-mentioned structure of the present invention, since the hull rotates so as to flutter to the water flow of the straightening vane according to the traveling direction of the hull, a lateral force is generated on the straightening vane by the water flow at the time of turning the hull or the water flow from the propeller. There is nothing to do.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, (1) is a hull, and the shaft bracket (4) of the present invention is attached to the lower surface of the bottom (2) of the hull (1) near the transom (3). The shaft bracket (4) has a flat plate-like flange (5), a cylindrical portion (6) depending from the lower surface of the flange (5), and a cylindrical shape integrally formed at the lower end of the cylindrical portion (6). Of the bearing (7), and the flange (5) is fixed to the ship bottom (2). The bearing (7) has a propeller shaft (8) inclined by θ _S.
And a propeller (9) is attached to the rear end of the propeller shaft (8). The rudder shaft (11) projects below the deck (16) on the rear side of the transom (3), and the rudder plate is arranged at the lower end of the rudder shaft (11) on the downstream side of the propeller (9). (12) is installed.

A straightening plate (13) is fitted on the cylindrical portion (6) of the shaft bracket (4) so as to be rotatable by 360 degrees. As shown in FIGS. 2 and 3, the side surface of the straightening vane (13) has a normal blade cross-sectional shape, and the columnar portion (a) is located at a position a behind the leading edge (15) by α. A shaft hole (14) for external fitting to 6) is formed so as to penetrate vertically. In this case, this straightening plate (13)
In order to make the water flow to the surrounding water flow, the distance d between the center point Z of the straightening vane shaft hole (14) and the leading edge (15) of the straightening vane (13) is d> with respect to the total length c of the straightening vane (13). c / 4. That is, in FIG. 3, the action point of the lateral force F _S generated on the straightening vane (13) when the straightening vane (13) having the blade shape is hit by running water having an angle of deviation is substantially rearward of the front edge (15). Since the position is c / 4, by providing the center Z of the shaft hole (14) in front of this point, the straightening vane (13) can always flow to the water flow.

FIG. 2 shows a case where the rudder blade (12) is steered to the right when the vehicle is moving forward to turn the hull to the left. in this case,
The water flow F at the position of the baffle plate (13) is the hull center line (X)
With an angle of deviation β. Since the baffle plate (13) is fluttering to this, the baffle plate center line (Y) has an angle of β with respect to the hull center line (X). Further, in FIG. 4, the upper edge of the current plate (13) is orthogonal to the center Z of the shaft tube, and the inclination angle θ _F of the front lower edge (23) and the rear lower edge inclination angle θ _A are the same. They are equal and symmetrical with respect to the axial tube center line (Z). That is, θ _F and θ _A are equal, and they are substantially equal to the propeller shaft inclination angle θ _S. Due to this shape, the current plate (13) is centered on the cylinder (6) and
There is no contact with other structures when rotating by 60 degrees.

FIG. 5 and subsequent figures show various structures for fitting the current plate (13) onto the columnar portion (6). First, in FIG. 5, the rectifying plate (13) is divided into front and rear at the shaft hole (14) portion, and these dividing members (17) are divided.
(18) is fitted into the columnar part (6) from the front and the back, and two stiffeners (19) and (19) are respectively provided on the side surface part thereof so as to straddle the split members (17) and (18). Therefore, they are fixed by welding or other means so as to be integrated. According to this method, there is an advantage that the resistance of the columnar plate (6) can be reduced by limiting the thickness of the straightening plate (13) and making the outer diameter of the columnar (6) the same.

In FIG. 6, the straightening vane (13) is divided into left and right parts along the plane of the longitudinal center line (Y) passing through the center of the shaft hole (14), and these dividing members (20) and (21) are divided into these parts. The right and left sides are fitted together, and the bolts (22) and (22) inserted into the dividing members (20) and (21) from the side direction are integrally coupled to each other.

In FIG. 7, the flow straightening plate (13) is divided into the front and rear as in the case of FIG. 5, but a cross-sectional shape that is easy to manufacture is used instead of the blade shape with low resistance as shown in FIG. Is. The dividing member (25) on the front side has a U-shaped cross section and has a recess (26) formed on the rear surface side thereof, and the recess (26) is formed on the tip surface of the dividing member (27) on the rear side. The protrusion (28) that fits with the protrusion (28) is integrally formed, and the tip end surface of the protrusion (28) is provided with a recess (2) that is rotationally fitted to the outer diameter of the columnar part (6).
9) forming. Then, these recesses (26) and recesses (29) are fitted from the front and back of the cylinder (6) to form the shaft hole (1
4) is formed, and a bolt (30) is laterally inserted into the overlapping portion of the projecting portion (28) and the front side dividing member (25) to integrally fasten and combine them.

Next, the operation of the ship equipped with the current plate (14) of the present invention at the time of turning will be described.

FIG. 8 shows a forward left turn, which can be better understood by comparing FIG. That is, in this state, the lateral force F _R is generated on the rudder blade in the starboard direction, but the lateral force F _S is not generated because the rectifying plate (13) is fluttered by the water flow having the deflection angle β. Therefore, turning can be performed with a smaller lateral force F _R than in the case of FIG.

That is, turning is possible even with a small rudder plate,
The rudder blade can be made smaller to reduce propulsion resistance and increase speed. Alternatively, since the vehicle turns by the lateral force F _R of the rudder blade (12), the steering effect is improved, and the vehicle can swiftly turn with a small turning radius.

FIG. 9 shows the situation when the vehicle is traveling straight backward and in this case,
The rudder blade (12) is parallel to the traveling direction, but due to the rotation of the propeller (9), a water flow having a deviation angle α is generated from the right rear side with respect to the flow straightening plate (13). , The straightening vane (13) reverses from the state of forward movement along the water flow so as to be in the front-back direction, and flows in the direction of the water flow.
No lateral force is generated on the current plate (13), and the hull (1) goes straight backward.

FIG. 10 shows a case where the vehicle is making a right turn in the reverse direction.
It is easy to understand when compared with Fig. 4. That is, since the water flow having the deflection angle α coming out of the propeller (9) hits the straightening vane (13) and the straightening vane (13) flutters to this, the lateral force F acts on the straightening vane (13).
_S does not occur. Therefore, the lateral force F _R generated on the rudder (12)
Can make a right turn.

FIG. 11 shows a case where the vehicle is making a right turn in the reverse direction.
With the same action as in Fig. 0, turning to the left is possible.

The lateral force F _R generated in the rudder blade (12) in the right turn according to FIG. 10 and the left turn according to FIG. 11 has the opposite directions and the same force, and therefore the turning force is also the same. As described above, the lateral force F _R generated on the rudder blade (12) when moving backward is smaller than that when moving forward, and therefore strong turning force cannot be expected in both left turning and right turning.

[0027]

As described above, according to the present invention, the straightening vanes rotate in accordance with the traveling direction of the hull, so that
Lateral force is not generated on the current plate due to the water flow during turning or the water flow from the propeller. Therefore, there is an effect that it is possible to obtain a ship capable of both right turning and left turning while reducing the resistance of the cylindrical portion of the shaft bracket by this straightening plate. In particular, in this invention,
It has an excellent advantage that it can enable the backward right turn, which has been a problem for many years.

[Brief description of drawings]

FIG. 1 is a side view of a portion near a hull transom showing an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of a hull portion near the transom.

FIG. 3 is an enlarged cross-sectional view of a current plate.

FIG. 4 is an enlarged vertical cross-sectional view of the current plate.

5A and 5B are a perspective view and a plan view of a straightening vane showing an example of a structure for attaching the straightening vane to a columnar portion.

FIG. 6 is a perspective view and a cross-sectional view of a current plate showing another example of a structure for attaching the current plate to a cylindrical portion.

7A and 7B are an exploded perspective view and a cross-sectional view of a current plate showing still another embodiment of the structure for attaching the current plate.

FIG. 8 is a schematic view of the entire hull showing the angles of the straightening vanes and the rudder blades when the hull is turned to the left.

FIG. 9 is an overall schematic view of the hull showing the rotation angles of the straightening vane and the rudder blade when the vehicle goes straight backward.

FIG. 10 is an overall schematic diagram of the hull showing the rotation angles of the rudder blade and the straightening vane when the vehicle makes a right turn in reverse.

FIG. 11 is an overall schematic diagram of the hull showing the rotation angles of the rudder blade and the straightening vane when the vehicle makes a reverse leftward turn.

FIG. 12 is a side view of a shaft bracket portion showing a conventional example provided with a plate portion.

FIG. 13 is an overall schematic diagram showing a lateral force of a rudder blade and a plate portion during a forward left turn in a conventional example.

FIG. 14 is a schematic diagram of the entire hull showing lateral forces of the rudder blade and the plate portion when the vehicle is turning left in the reverse direction according to the conventional example.

FIG. 15 is an overall schematic diagram showing a situation when a vehicle is making a right turn in reverse in a conventional example.

[Explanation of symbols]

 (1) Hull (4) Shaft bracket (6) Column (8) Propeller shaft (9) Propeller (13) Current plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsumi Kikuya, Inventor Katsumi Kikuya, 1 Ugado, Ushimado-cho, Okayama Prefecture 1449 No. 1 at YUMMA Shipbuilding Co., Ltd. (72) Inventor Toshihiko Sugihara 1 at 6449 Ushimado, Ushimado-cho, Oku-gun, Okayama Yanmar Shipbuilding Co., Ltd.

Claims (1)

[Claims] 1. A lower end of a cylindrical portion projecting downward from a ship bottom,
A shaft bracket device for a ship, comprising: a shaft bracket provided with a propeller bearing for supporting a propeller shaft, wherein a straightening plate rotatable by 360 degrees is rotatably fitted to the cylindrical portion.