JPH04283192A - Catamaran - Google Patents

Abstract

PURPOSE:To provide a catamaran which is sufficiently durable in terms of strength even when concentration of a stress occurs to a mounting part between a coupling part and a deck in a state, such as a state in waves, where an external force is exerted. CONSTITUTION:The width of a coupling part 4 is gradually increased from a mounting part 7 toward a mounting part 5. Two sides 4a and 4b of the coupling part 4 are formed in a curve throughout a portion ranging from the part 7 to the part 5.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a catamaran sailing in waves.

0002

[Prior Art] Two
A catamaran is known that has two monohulls connected together by one deck. In conventional catamarans, most of the displacement was made up of submerged bodies with an elliptical cross section, and the connecting parts above the water surface were wider than the water surface. For this reason, although the stability is good, the synchronization period of the oscillation is short, and the wave forcing force is large, so there is a problem that the oscillation in waves becomes large.

[0003] As a means to solve such problems, a catamaran boat with an improved structure of a semi-submerged part and a connecting part is known, which is disclosed in Japanese Patent Application Laid-Open No. 2-182594. The catamaran disclosed in the above publication is as follows. Two single hulls arranged in parallel with a predetermined interval are connected together by one deck, each of the two single hulls is connected to a semi-submerged part, and the semi-submerged part is connected to the deck. The width of the semi-submerged part is the maximum width near the water surface, and the width of the semi-submerged part rapidly decreases upward from near the water surface, The width of the connecting part,
A catamaran (
(hereinafter referred to as "prior art 1").

FIG. 6 is a schematic side view showing a catamaran disclosed in Prior Art 1, and FIG. 7 is a sectional view taken along line AA in FIG. As shown in the drawing, in the catamaran of Prior Art 1, each of two monohulls 1, 1 each consisting of a connecting part 4 and a semi-submerged part 3 arranged at regular intervals has a semi-submerged part. The width is maximum near 3. The width of the semi-submerged part 3 rapidly decreases upward from the vicinity of the water surface 6, while the width gradually decreases downward from the vicinity of the water surface to the bottom end. It is formed.

[0005] In the catamaran of Prior Art 1, the width of the single hull (the width of the half-submerged part) rapidly decreases upward from the widest part near the water surface, so that when the hull sinks into the water, The restoring force becomes smaller, the tuning period of the oscillation becomes longer, and the amplitude of the oscillation becomes smaller in the normal wave period. On the other hand, even if it enters the waves, the width of the single shell 1 decreases rapidly upward from the maximum width part, so the wave pressure acting on the upper surface of the single shell 1 than the maximum width part and the lower surface Since the vertical components of the wave pressure acting on the waves cancel each other out, the wave forcing force in the vertical direction is reduced, and the vibration amplitude is reduced, among other features.

[0006]

[Problems to be Solved by the Invention] However, the catamaran of Prior Art 1 has the following problems. The connecting portion 4 is formed to be narrower than the maximum width portion of the semi-submerged portion 3 near the water surface, and to have a constant width. As shown in FIG. 8, the connecting portion 4 is formed in a shape in which the width rapidly increases upward at the attachment portion 5 to the deck 2. As shown in FIG. Alternatively, it is attached to deck 2 with its width unchanged. Therefore,
The connecting portion 4 has a discontinuous portion in the cross-sectional shape of the attachment portion 5, and stress concentration is likely to occur in a state where an external force is applied, such as during waves, resulting in a strength problem.

[0007] Accordingly, an object of the present invention is to provide a catamaran having a shape that prevents excessive stress concentration from occurring in the attachment portion 5 between the connecting portion 4 and the deck 2 under conditions where external forces are applied, such as during waves. be.

[0008]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, two single hulls 1, 1 arranged in parallel with a predetermined interval are integrally connected by one deck 2. Each of the two single hulls 1, 1 is composed of a semi-submerged part 3 and a connecting part 4 that connects the semi-submerged part 3 to the deck 2, and the width of the semi-submerged part 3 is set to the maximum near the water surface. The width of the semi-submerged part 3 is formed so that the width of the semi-submerged part 3 rapidly decreases upward from near the water surface, and the width of the attachment part 7 of the connecting part 4 to the semi-submerged part 3 is set to In a catamaran in which the width is the same as the rapidly reduced width of 3, and the width of the attachment part 5 of the connection part 4 to the deck 2 is larger than the width of the attachment part 7, the intermediate part in the height direction of the connection part 4 Alternatively, the width of the connecting portion 4 is gradually increased from the attachment portion 7 to the attachment portion 5.

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a connecting portion showing a first embodiment of the present invention. As shown in the drawings, the single shell 1 has a maximum width near the water surface of the semi-submerged part 3. The width of the semi-submerged part 3 rapidly decreases upward from near the water surface, while from near the water surface to the bottom end,
It is formed in the shape of a "V" whose width gradually decreases toward the bottom. The width of the connecting part 4 is from the mounting part 7 to the mounting part 5.
, and both sides 4a of the connecting portion 4
, 4b are constituted by a concave curved surface from the attachment portion 7 to the attachment portion 5.

By forming the connecting portion 4 in such a shape that the width begins to increase from the attachment portion 7, there is no discontinuous portion in the vertical cross section of the connecting portion 4, and it is possible to avoid external forces such as during waves. The mounting portion 5 can be shaped in such a way that excessive stress concentration does not occur in the working state. On the other hand, in the attachment part 7, the width of the connecting part 4 is smaller than the width of the semi-submerged part 3 near the water surface, as in the prior art 1, and has almost no effect on the wave motion performance.

FIG. 2 is a vertical cross-sectional view of a connecting portion showing a second embodiment of the present invention. As shown in the drawing, the connecting part 4
The width is constant from the attachment portion 7 to the center of the connecting portion 4. The width of the connecting portion 4 gradually increases from the central portion to the attachment portion 5, and both side surfaces 4a and 4b of the connecting portion 4 are formed by inclined planes from the central portion to the attachment portion 5. . In this embodiment as well, the first
Effects similar to those of the embodiment can be obtained.

FIG. 3 is a vertical cross-sectional view of a connecting portion showing a third embodiment of the present invention. As shown in the drawing, the connecting part 4
The width is constant from the attachment part 7 to the middle part of the connecting part 4. The width of the connecting portion 4 gradually increases from the central portion to the attachment portion 5, and both side surfaces 4a and 4b of the connecting portion 4 are formed by concave curved surfaces from the central portion to the attachment portion 5. There is. In this embodiment as well, the first
Effects similar to those of the embodiment can be obtained.

FIG. 4 is a vertical cross-sectional view of a connecting portion showing a fourth embodiment of the present invention. As shown in the drawings, in this embodiment, the shapes of the inner surface 4a and the outer surface 4b of the connecting portion 4 are changed. That is, the width of the connecting portion 4 gradually increases from the attachment portion 7 toward the upper attachment portion 5, and the width of the attachment portion 7 increases on the inner surface 4a of the connecting portion 4.
The mounting portion 5 is formed by a concave curved surface. On the other hand, on the outer surface 4b of the connecting portion 4, the attachment portion 7
The area from the central part to the central part is a vertical plane, and the area from the central part to the attachment part 5 is an inclined plane. This embodiment also provides the same effects as the first embodiment.

Further, as shown in FIG. 5, in the first to fourth embodiments, the inner surface 4a or outer surface 4b of the connecting portion 4 may be configured as a vertical plane from the mounting portion 7 to the mounting portion 5. good.

Since the catamaran of the present invention is constructed as described above, even though it has a structure in which the strength of the connecting part and the deck is strengthened, In rocking, it can exhibit the same rocking performance in waves as the catamaran of Prior Art 1.

[0016]

[Effects of the Invention] As explained above, according to the present invention, a catamaran can be obtained which can strengthen the attachment part between the connecting part and the deck and has the same rocking performance as a conventional catamaran. Industrially useful effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a connecting portion showing a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a connecting portion showing a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a connecting portion showing a third embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a connecting portion showing a fourth embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a connecting portion showing a fifth embodiment of the present invention.

[Fig. 6] Schematic side view of the catamaran disclosed in Prior Art 1

[
Figure 7: Cross-sectional view taken along line AA in Figure 6

[Explanation of symbols]

1 Single body 2 Deck 3　Semi-submerged part 4 Connecting part 4a　Inner surface 4b Outer surface 5. Attachment part between connecting part and deck 6 Water surface

Claims (6)

[Claims] [Claim 1] Two parts arranged in parallel at a predetermined interval.
Two single hulls 1, 1 are integrally connected by one deck 2, each of the two single hulls 1, 1 has a semi-submerged part 3, and a connecting part 4 that connects the semi-submerged part 3 to the deck 2. The width of the semi-submerged part 3 is the maximum near the water surface, and the width of the semi-submerged part 3 rapidly decreases upward from near the water surface. The width of the attachment part 7 with the semi-submerged part 3 is the same as the rapidly reduced width of the semi-submerged part 3, and the width of the attachment part 5 of the connecting part 4 with the deck 2 is wider than the width of the attachment part 7. This catamaran is characterized in that the width of the connecting part 4 is gradually increased continuously from the intermediate part in the height direction of the connecting part 4 or the attachment part 7 toward the attachment part 5. 2. The width of the connecting portion 4 is gradually increased from the mounting portion 7 to the mounting portion 5, and both sides 4 of the connecting portion 4 are
2. A catamaran according to claim 1, wherein a and 4b are curved surfaces from the mounting portion 7 to the mounting portion 5. 3. The width of the connecting portion 4 is constant from the mounting portion 7 to the center portion in the height direction of the connecting portion 4, and the width of the connecting portion 4 is gradually increased from the center portion toward the mounting portion 5, The catamaran according to claim 1, wherein both side surfaces (4a, 4b) of the connecting portion (4) are formed by inclined planes from the central portion to the attachment portion (5). 4. The width of the connecting portion 4 is constant from the mounting portion 7 to the center portion in the height direction of the connecting portion 4, and the width of the connecting portion 4 is gradually increased from the center portion toward the mounting portion 5, 2. The catamaran according to claim 1, wherein both side surfaces 4a and 4b of the connecting portion 4 are curved surfaces from the central portion to the attachment portion 5. 5. The width of the connecting portion 4 is gradually increased from the mounting portion 7 to the upper mounting portion 5, and the inner surface 4a of the connecting portion 4 is configured as a curved surface from the mounting portion 7 to the mounting portion 5, The catamaran according to claim 1, wherein the outer surface 4b of the connecting portion 4 is formed by a vertical plane from the mounting portion 7 to the central portion, and is formed by an inclined plane from the central portion to the mounting portion 5. [Claim 6] Inner surface 4a or outer surface 4 of connecting portion 4
6. A catamaran according to claim 1, wherein b constitutes a vertical plane from the attachment part 7 to the attachment part 5.