JP3392673B2 - Water jet duct support structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be applied to a water jet duct supporting portion of a water jet propulsion device for a water jet propulsion system, such as a high speed boat, a regular ship such as a ferry, or a marine structure. A possible water jet duct support structure.

[0002]

2. Description of the Related Art Conventionally, an aluminum alloy material is often used as a structural material of a hull in a ship such as a normal high speed ship, and a normal ship such as a high speed ship or a ferry which adopts a water jet propulsion system, When supporting the water jet duct related to the water jet propulsion device on the hull or floating body of an offshore structure, in the water jet duct support part, directly weld the plate or the bent plate part of the aggregate structure by welding, and simply A folded plate welded structure was used to support the water jet duct.

FIG. 3 (1) is a side view of a main part of a conventional water jet duct support structure, and FIG. 3 (2) is a rear sectional view of the main part of the water jet duct support structure of FIG. 3 (1). 3 (1) as viewed from the direction of the EE line, FIG.
FIG. 3C is an enlarged detailed view of an F portion of FIG.

In FIGS. 3 (1) to 3 (3), a water jet duct 01 penetrates from the inside of the ship through the bottom portion 02 and projects to the outside of the water jet duct 01.
The water sucked from the suction port is pressurized and jetted from the rear jet port toward the rear of the stern. Portion of the tie-supporting structure in the side shell 03 and 04 and the ship bottom 02 Metropolitan showing a water jet duct 01 as side shell of the hull part of the support for example catamaran type has a narrow portion. In addition, the bent plate portion 0 at the connecting portion between the ship bottom portion 02 and the ship side outer plate 03
5 is often a welded joint.

[0005]

By the way, in the bent plate portion 05 and the fillet portion 06 connecting the ship bottom portion 02 to the water jet duct 01, due to the repeated load of the external fluid force received from the external fluid, Since there is a concern that stress may increase and fatigue cracks may occur, it is desired to increase the fatigue strength of such a joint portion to further improve the reliability of structural strength.

Therefore, the present invention is to provide a water jet duct supporting structure which can reduce stress concentration and further enhance fatigue strength in the water jet duct supporting structure.

[0007]

In order to solve the above-mentioned problems, a mating support portion which constitutes the water jet duct support structure of the present invention, that is, water for thrust generation that projects from the inside of the ship to the outside of the ship through the bottom of the ship. In the mating support part by the bottom of the water jet duct and the outer shell of the water jet duct that sucks in and guides it to the rear injection port, smoothly by butt welding to the upper duct wall part above the bottom part of the water jet duct. An upper duct wall connecting portion that is continuously connected, and a lower duct wall connecting portion that is smoothly and continuously connected to the lower duct wall portion of the water jet duct below the ship bottom portion by butt welding. The metal fitting also integrally has a ship-side outer plate connecting portion that smoothly and continuously connects to the ship-side outer plate by butt welding. Section, the surface connected to the lower duct wall section and the ship side skin, respectively, and the surface extending from the upper duct wall connection section to the ship side shell connection section and the lower duct wall connection section to the ship side shell connection section. The surfaces leading up to each form a smoothly continuous curved surface.

The water jet duct supporting structure of the present invention is a mating support portion, that is, it penetrates from the inside of the ship through the bottom of the ship to the outside of the ship, sucks the thrust generating jet water, and guides it to the rear jet port. At the bottom of the water jet duct and the mating support by the outer shell of the ship, at the corner of the bottom of the bottom of the ship and the wall of the water jet duct, a number of brackets parallel to the transverse direction of the hull are provided. , Welded and arranged at intervals from each other, and the edges of the brackets along the bottom of the ship join from the corners of the bottom of the bracket with the water jet duct to the outer shell of the ship. Welded to the bottom of the ship and extending to a position in the vicinity of the section, and the edges of the brackets along the wall of the water jet duct are the same as the water jet. The brackets are welded to the wall of the air duct, and the brackets are reinforced and reduce the fluid resistance along the free edge from the tip of the bracket on the bottom side to the tip of the water jet duct on the wall side. The flange for is formed.

Further, in the water jet duct supporting structure of the present invention, the free edges of the brackets are
A smooth arc-shaped concave curved surface is formed from the tip end on the ship bottom side to the tip end on the wall side of the water jet duct.

Further, in the water jet duct supporting structure of the present invention, the water jet duct has the bottom portion and the mating support portion by the outer shell of the water jet duct. It is a mating support part with the outer plate.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 (1) is a side view of an essential part of a water jet duct support structure according to an embodiment of the present invention, and FIG. 1 (2) is a rear sectional view of an essential part of the water jet duct support structure of FIG. 1 (1). Then, the figure seen from the direction of the AA line in FIG. 1 (1), and FIG. 1 (3) is an enlarged detailed view of the B portion of FIG.

1 (1) to 1 (3), the water jet duct 1a penetrates through the bottom 2a of the ship and projects to the outside of the ship so as to suck the thrust generating water and guide it to the rear injection port. It is configured. The mating support portion of the water jet duct 1a by the ship bottom portion 2a and the side plate 3a is, for example, the water jet duct 1a and the stern ship bottom 2 in the stern portion of a catamaran type high speed ship.
It is shown as a mating support with a and the side shell 3a.

The metal fitting 7a is the water jet duct 1
an upper duct wall connecting portion 17a for connecting than a ship bottom portion 2a smoothly and continuously through the butt weld 10a above the upper duct wall section 16a, below the vessel bottom portion 2a of the water jet duct 1a Has a thickened portion 13a
And a lower duct wall connecting portion 19a which connects smoothly and continuously through the butt weld 9a to the lower duct wall portion 18a, butt weld side shell 3a in the bracket 7a Gasa et al It also integrally has a ship side outer plate connecting portion 20a that is smoothly and continuously connected via 8a.

[0014] As described above, fitting 7a is longitudinal section has a fitting of substantially Y-shaped, water jet duct 1a of the vessel bottom portion 2a above the upper duct wall portion 16 than
a, the lower duct wall portion 18a below the ship bottom portion 2a of the water jet duct 1a, and the ship side outer plate 3a. The fitting 7a has a continuous surface 11a further extends from the continuous surface 12a Contact and lower duct wall connecting portion 19a extending from the upper duct wall connecting portion 17a to the side shell plate connecting portion 20a to the side shell plate connecting portion 20a The surfaces 12a and 11a form smoothly continuous curved surfaces.

In the water jet duct support structure shown in FIGS . 1 (1) to 1 (3), the metal fitting 7a can be manufactured by, for example, extrusion or machining. As the welded portion, butt welded portions 8a, 9a, 10a
And only, it is to avoid the fatigue strength UeYoshimi Mashi wards fillet weld. Further, the shape of the metal fitting 7a is the above-mentioned surfaces 12a, 1
Since the outer wall of the water jet duct 1a is subjected to the load of the external force, the stress is favorably dispersed and the stress concentration can be reduced by being formed by the smoothly continuous curved surface like 1a.

According to a waterjet duct support structure shown in to FIG. 1 (1) 1 (3), by a high stress that eliminate the welding in prone portion occurs, the water jet duct support structure of life The life of the conventional water jet duct support structure can be at least 10 times longer than that of the conventional water jet duct support structure. Further, by adopting the Y-shaped metal fitting 7a, the stress concentration rate can be reduced by about 50% as compared with the case of the conventional water jet duct support structure, and in that case, the life of the water jet duct support structure is reduced. , And about (1.5) ⁴ ≒ 5
It can be extended twice.

FIG. 2 (1) is a side view of an essential part of a water jet duct support structure according to another embodiment of the present invention, and FIG. 2 (2) is an essential part of the water jet duct support structure of FIG. 2 (1). FIG. 3 is a rear cross-sectional view as seen from the direction of the line C-C in FIG. 2 (1), and FIG. 2 (3) is an enlarged detailed view of a D portion in FIG. 2 (2).

2 (1) to 2 (3), the water jet duct 1b penetrates through the bottom 2b of the ship and projects out of the ship, sucks thrust generating water and guides it to the rear injection port. Is configured. This water jet duct 1b has a ship bottom portion 2b and a ship side outer plate 3
The mating support part with b is shown as an example of the mating support part between the water jet duct 1b in the stern part of the catamaran high-speed ship, the stern bottom 2b and the side plate 3b.

A large number of brackets 7b parallel to the transverse direction of the hull are welded to each other at the corners between the bottom 2b of the bottom 2b and the wall of the water jet duct 1b at intervals. It is joined. The edge of each bracket 7b along the bottom 2b extends from the corner 6b between the bottom 2b and the water jet duct 1b to a position in the vicinity of the joint to the side shell of the bottom of the bottom 2b. It is welded. The edge of each bracket 7b along the wall of the water jet duct 1b is welded to the wall of the water jet duct 1b. Each of the brackets 7b crosses the hull as described above along the free edge 9b from the tip of the bracket 7b on the bottom 2b side to the tip of the water jet duct 1b on the wall side.
In the shape of a flange for each bracket 7b parallel to the direction,
That is, the hull of the hull is shaped like a collar against the plate surface of each bracket 7b.
Flange 15 for reinforcement and fluid resistance reduction protruding in the front-rear direction
b is formed.

The free edge portion 9b of each bracket 7b forms a smooth arc-shaped concave curved surface from the tip portion on the ship bottom portion 2b side to the tip portion on the wall portion side of the water jet duct 1b. The flange 15b is welded to the free edge portion 9b of the bracket 7b so as to be effective in bending the ship bottom portion 2b. Further, an intersecting portion 14b that intersects with the thickened portion 13b as the position of the current plate of the water jet duct 1b.
By arranging the bracket 7b of at least three plates, the bending stress of the bent plate connecting portion 5b when the outer wall of the water jet duct 1b receives a lateral load can be reduced and the fatigue strength can be improved. it can.

According to the water jet duct supporting structure shown in FIGS . 2 (1) to 2 (3), the bending stress of the bent plate portion due to the lateral load acting on the duct wall of the water jet duct 1b is prevented from the conventional water. Compared to the jet duct support structure, it can be reduced by about 40%, and the fatigue life can be extended to about 5 times longer.

[0022]

As described above, according to the water jet duct supporting structure of the present invention, the following effects can be obtained. (1) Water jet duct of the invention according to claim 1
According to the supporting structure, in the above-mentioned bottom portion of the water jet duct for projecting to the outside of the vessel through the bottom portion of the vessel, projecting to the outside of the vessel, and sucking the thrust generating water and guiding it to the rear jet port, and the joint support portion by the side plate of the side, An upper duct wall connecting portion that smoothly and continuously connects to an upper duct wall portion above the water bottom of the water jet duct by butt welding, and a lower duct wall lower than the bottom portion of the water jet duct. Metal fittings having a lower duct wall connecting part that is smoothly and continuously connected to the ship part by butt welding, and a ship-side outer plate connecting part that is smoothly and continuously connected to the ship-side outer plate by butt welding are also integrated. And is connected to the upper duct wall portion, the lower duct wall portion, and the ship side outer plate, respectively, and further, the upper duct wall connecting portion connects the ship side outer plate. Since the surface leading to the section and the surface leading from the lower duct wall connecting part to the ship side outer plate connecting part each form a smooth continuous curved surface, eliminate the welded joint of the bent plate part where the stress becomes high. Since stress can be smoothly dispersed and transmitted, stress concentration can be reduced and fatigue strength can be increased. (2) The water jet duct of the invention according to claim 2
According to the support structure, the water jet duct, which penetrates the ship bottom from the inside of the ship to the outside of the ship, sucks thrust-generating water and guides it to the rear injection port, is attached to the bottom part of the water jet duct and the side plate to support the ship. A number of brackets parallel to the transverse direction of the hull are arranged at intervals at the corners between the bottom of the ship and the wall of the water jet duct on the bottom side of the bottom, and are welded together at intervals. The edge along the bottom of the ship extends from a corner between the water jet duct of the bottom of the ship to a position in the vicinity of the joint to the side shell and is welded to the bottom of the ship. An edge portion along the wall portion of the water jet duct of the bracket is welded to the wall portion of the water jet duct, and each bracket is attached to the bottom portion side of each of the brackets. Since a flange for reinforcing and reducing fluid resistance is formed along the free edge from the end to the tip on the wall side of the water jet duct, a flanged bracket is often used in the bent plate weld where stress increases. By arranging them in rows, the bending stress in the bent plate welds can be reduced and the fatigue strength can be increased, the flange plate can also serve as a straightening plate, reduce the fluid resistance, and reduce the bending plate welds. By reducing the stress,
Fatigue strength can be increased. (3) The water jet duct of the invention according to claim 3
According to the support structure, the free edge of each bracket forms a smooth arc-shaped concave curved surface from the tip of the ship bottom to the tip of the wall of the water jet duct. It is possible to satisfactorily disperse the generated stress, reduce the stress concentration in the bracket and its surroundings, and increase the fatigue strength. (4) The water jet duct of the invention according to claim 4
According to the support structure, the mating support part of the water jet duct by the ship bottom part and the side plate is the mating support part of the water jet duct and the stern bottom and the ship side plate at the stern part of the catamaran type high speed ship. So
In the stern of a catamaran type high speed ship where special consideration is required for stress concentration and fatigue strength at the joint between the bottom of the water jet duct and the outer skin of the side of the ship, and between the water jet duct and the stern bottom and the outer skin of the side. Stress concentration can be reduced and fatigue strength can be increased in the mating support portion.

[Brief description of drawings]

FIG . 1 (1) is a side view of a main part of a water jet duct support structure according to an embodiment of the present invention .
1 (2) is a rear cross-sectional view of a main part of the water jet duct support structure of FIG. 1 (1), which is taken along the line AA of FIG.
It is the figure seen from the direction of a line, and FIG. 1 (3) is an enlarged detailed view of the B section of FIG. 1 (2).

FIG . 2 (1) is a side view of a main part of a water jet duct support structure according to another embodiment of the present invention,
2 (2) is a rear cross-sectional view of the main part of the water jet duct support structure of FIG. 2 (1), taken along line CC of FIG. 2 (1).
It is the figure seen from the direction of a line, and FIG. 2 (3) is an enlarged detailed view of the D section of FIG. 2 (2).

FIG . 3 (1) is a side view of a main part of a conventional water jet duct support structure, and FIG. 3 (2) is FIG. 3 (1).
FIG. 4 is a rear sectional view of a main part of the water jet duct support structure of FIG. 3, viewed from the direction of the line E-E of FIG. 3 (1), and FIG. FIG.

[Explanation of symbols]

01 water jet duct 02 bottom 03 Ship side skin 04 Ship side skin 05 Folded plate part 06 fillet 1a, 1b Water jet duct 2b Ship bottom 3a, 3b Ship side outer plate 4a, 4b Ship side outer plate 5b Bent plate part 6b corner 7a Y-shaped metal fittings 7b bracket 8a Butt weld 9a Butt weld 10a Butt weld 11a, 12a surface 13a, 13b thickened portion 14b Crossover 15b flange 16a Upper duct wall 17a Upper duct wall connection part 18a Lower duct wall 19a Lower duct wall connection part 20a Ship side outer plate connection part

Claims (4)

(57) [Claims] 1. A water jet duct that penetrates through a ship bottom from the inside of the ship to the outside of the ship to suck thrust generating water and guide it to a rear injection port, wherein the water is at the bottom of the water jet duct and the mating support by the side plates. An upper duct wall connecting portion that smoothly and continuously connects to an upper duct wall portion above the bottom of the jet duct by butt welding, and a lower duct wall portion below the bottom of the water jet duct. A metal fitting having a lower duct wall connection part that is smoothly and continuously connected by butt welding also integrally has a ship-side outer plate connection part that is smoothly and continuously connected to the ship-side outer plate by butt welding. And is connected to the upper duct wall portion, the lower duct wall portion, and the ship side skin, respectively, and further, from the upper duct wall connection portion to the ship side skin plate connection portion. And a surface extending from the lower duct wall connecting portion to the ship side outer plate connecting portion each form a smoothly continuous curved surface. 2. The bottom of the water jet duct, which penetrates through the bottom of the boat and projects to the outside of the boat, sucks thrust-generating water, and guides it to a rear jet port, at the above-mentioned bottom of the jet jet and the side plate of the boat. At the corner between the bottom of the ship and the wall of the water jet duct on the underside, a number of brackets parallel to the transverse direction of the hull are arranged at intervals and welded together. An edge portion along the bottom of the ship extends from a corner between the water bottom of the bottom of the ship and the water jet duct to a position in the vicinity of a joint to the side shell of the ship and is welded to the bottom of the ship, and each of the brackets is welded. The edge portion along the wall portion of the water jet duct is welded to the wall portion of the water jet duct, and each bracket has a tip end portion on the ship bottom side of each bracket. To a wall end of the water jet duct, a reinforcing and fluid resistance reducing flange is formed along a free edge portion of the water jet duct. 3. The water jet duct supporting structure according to claim 2, wherein a free edge portion of each of the brackets has a smooth arc shape from a tip end portion on the ship bottom side to a tip end on a wall portion side of the water jet duct. A water jet duct support structure characterized by having a concave curved surface. 4. The water jet duct support structure according to any one of claims 1 to 3, wherein the water jet duct has a bottom portion and a mating support portion formed by a side shell of the water jet duct, the stern of a catamaran type high speed ship. A water jet duct support structure, which is a mating support portion of a water jet duct with a stern bottom and a side skin of a ship.