Planing boat and method for manufacturing the same

Abstract

A planning boat includes at least one tank provided on a bottom of the boat. The tank has, at a stern side, a wall through which a through hole is provided below a waterline. A hull of the planning boat includes a bottom plate that forms the bottom of the boat, right and left side plates that form sides of the boat and a bow, a transom plate that forms a stern, and a plurality of longitudinal vertical plates. The plurality of longitudinal vertical plates each extend between the transom plate and forward portions of the side plates along a sailing direction and each have a lower surface that is fixed to an upper surface of the bottom plate. The tank is formed by using the pair of longitudinal vertical plates of the existing planning boat.

Claims

1. An anti-rocking device in a planing boat, wherein a hull of the planing boat comprises: a bottom plate that forms a bottom of the boat; right and left side plates that form sides of the boat and a bow; a transom plate that forms a stern; and a plurality of longitudinal vertical plates each extending between the transom plate and forward portions of the side plates along a sailing direction and each having a lower surface that is fixed to an upper surface of the bottom plate, a right engine is disposed at a right part of the hull and a left engine is disposed at a left part of the hull, the plurality of longitudinal vertical plates includes: outside right and left longitudinal vertical plates situated near the right and left side plates, respectively; and inside right and left longitudinal vertical plates situated closer to a center of the hull in relation to the outside right and left longitudinal vertical plates, the right engine is supported by the outside right longitudinal vertical plate and the inside right longitudinal vertical plate, and the left engine is supported by the outside left longitudinal vertical plate and the inside left longitudinal vertical plate, and the anti-rocking device comprises: a tank; and a through hole, in which the tank is provided on the bottom of the boat, and the tank has, at a stern side, a wall through which the through hole is provided below a waterline, wherein a top plate is provided between upper portions of the inside right and left longitudinal vertical plates, the tank being formed by the inside right and left longitudinal vertical plates, the top plate, a part of the bottom plate, a part of the transom plate, and a part of each of the right and left side plates, wherein the through hole is formed through the transom plate, and wherein, when the boat is moored, the tank is filled with water and a center of gravity of the planing boat is lowered such that a proportion of a portion of the right and left engines that are below the waterline is greater than the proportion in a state where the tank is empty when the boat sails.

2. The anti-rocking device in the planing boat according to claim 1, wherein a communicating tube for providing communication between an inside and an outside of the tank is provided at a bow end portion of the top plate of the tank.

3. The anti-rocking device in the planing boat according to claim 1, wherein a lid that opens/closes the through hole is provided.

4. A method for manufacturing an anti-rocking device in a planing boat, wherein a hull of the planing boat comprises: a bottom plate that forms a bottom of the boat; right and left side plates that form sides of the boat and a bow; a transom plate that forms a stern; and a plurality of longitudinal vertical plates each extending between the transom plate and forward portions of the side plates along a sailing direction and each having a lower surface that is fixed to an upper surface of the bottom plate, and the anti-rocking device includes: a tank; and a through hole, in which the tank is provided on the bottom of the boat, and the tank has, at a stern side, a wall through which the through hole is provided below a waterline, the method for manufacturing the anti-rocking device comprising: placing a top plate between upper portions of the existing pair of longitudinal vertical plates to form the tank defined by the existing pair of longitudinal vertical plates, the top plate, a part of the existing bottom plate, a part of the existing transom plate, and a part of each of the existing right and left side plates; and forming the through hole through the transom plate.

5. The method for manufacturing the anti-rocking device in a planing boat according to claim 4, further comprising: placing a communicating tube for providing communication between an inside and an outside of the tank at a bow end portion of the top plate of the tank.

6. The method for manufacturing the anti-rocking device in a planing boat according to claim 4, further comprising: placing a lid that opens/closes the through hole.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a back view of a planing boat, when moored, according to a first embodiment of the present invention.

(2) FIG. 2 is a transverse sectional view of the planing boat, when moored, according to the first embodiment.

(3) FIG. 3 is a longitudinal sectional view (a cross section along the center line of an anti-rocking device) of the planing boat, when moored, according to the first embodiment.

(4) FIG. 4 includes a longitudinal sectional view of a conventional planing boat, when moored, and the longitudinal sectional view of the planing boat, when moored, according to the first embodiment of the present invention, which are shown for comparison.

(5) FIG. 5 is a longitudinal sectional view of the planing boat, when sailing, according to the first embodiment.

(6) FIG. 6 is a back view of a planing boat, when moored, according to a second embodiment of the present invention.

(7) FIG. 7 is a transverse sectional view of the planing boat, when moored, according to the second embodiment.

(8) FIG. 8 is a sectional view along the center line of an anti-rocking device of the planing boat, when moored, according to the second embodiment.

(9) FIG. 9 is a longitudinal sectional view (a cross section along the center line of an anti-rocking device) of a planing boat, when moored, according to a third embodiment.

(10) FIG. 10 is a longitudinal sectional view of the planing boat, when sailing, according to the third embodiment.

DESCRIPTION OF EMBODIMENTS

(11) Embodiments of the present invention will now be described with reference to the drawings.

(12) FIG. 1 to FIG. 3 show a planing boat, when moored, according to a first embodiment of the present invention. A boat (1) includes: a hull (2) made of fiberglass reinforced plastic (FRP); a deck (3) made of FRP and joined to an outer edge of an upper portion of the hull (2); and a cabin (4) provided to project from the deck (3).

(13) The hull (2) includes: a bottom plate (5) that forms the bottom of the boat; right and left side plates (6) that form the sides of the boat and a bow; a transom plate (7) that forms a stern; and four longitudinal vertical plates (8) and (9) each extending between the transom plate (7) and forward portions of the right and left side plates (6) along a sailing direction and each having a lower surface that is fixed to an upper surface of the bottom plate (5).

(14) The four longitudinal vertical plates (8) and (9) are arranged symmetrically in the right and left direction. Between each pair of the longitudinal vertical plates (8) and (9), an engine (10) supported by an engine mount is disposed. The boat (1) thus has two engines disposed at the right and left parts of the boat (1).

(15) The structure described above is the same as that of the conventional planing boat. The planing boat (1) in accordance with the present invention further includes an anti-rocking device (11).

(16) The anti-rocking device (11) has a tank (12) for storing water. Between upper ends of the two longitudinal vertical plates (8), which are arranged to the center, a top plate (13) is laid. The pair of longitudinal vertical plates (8), the top plate (13), a part of the bottom plate (5), a part of the transom plate (7), and a bow end portion of each of the right and left side plates (6) form an enclosed space to constitute the tank (12).

(17) The transom plate (7) has a through hole (14) that allows water (seawater or fresh water) to flow into/out of the tank (12). The through hole (14) is provided below the waterline (i.e., a water surface (H)) on the transom plate (7) (a wall on the stern side of the tank (12)). With this structure, when the boat (1) is moored, the water flows into the tank (12) whereby the tank (12) is filled with water.

(18) As shown in FIG. 3, at the front end portion (bow side) of the tank (12), a communicating tube (15) that allows air to flow in and out of the tank (11) is provided. The communicating tube (15) has one end that is inserted into a through hole (13a) formed at a front end portion of the top plate (13) and the other end that is inserted into a through hole (6a) formed at a bow end portion of the side plates (6). When the water flows into the tank (12) when the boat is moored, air within the tank (12) escapes through the communicating tube (15) to the outside, whereby the pressure in the tank (12) at the bow side is maintained at atmospheric pressure. In this manner, the tank (12) is filled with water in a manner such that the water is not hindered from flowing into the tank (12) by air.

(19) The tank (12), the through hole (14), and the communicating tube (15) constitute the anti-rocking device (11). Here, the longitudinal vertical plates (8), the bottom plate (5), the transom plate (7), and the side plates (6) are used to form the tank (12). These plates (8), (5), (7), and (6) are provided to an existing boat. Therefore, to form the anti-rocking device (11), only the processes of placing the top plate (13), forming the through hole (14), and placing the communicating tube (15) are required as additional processes.

(20) FIG. 4 shows a boat (1) according to the first embodiment of the present invention shown in FIG. 2 and a conventional boat (P), for comparison. In the boat (1) according to the first embodiment, the tank (12) is filled with water. Therefore, the total weight of the boat (1) increases as compared to the conventional boat (P), the waterline (L1) rises as compared to the waterline (L2) of the conventional boat (P), and the bottom portion of the boat (1) becomes heavier whereby the center of gravity is lowered. As a result, the degree of the rocking of the boat (1), when moored, is less than that of the conventional boat (P).

(21) When the planning boat (1) starts sailing and the sailing speed exceeds a certain value, the bow rises above the surface of the water and the boat starts pushing water away at an area behind the stern, as shown in FIG. 5. In this situation, since the tank (12) that has been horizontal when the boat (1) is moored, is inclined upward toward the bow side, and no water exists outside around the stern, water in the tank (12) is discharged through the through hole (14) formed through the transom plate (7) to the outside the hull (2), whereby the tank (12) is emptied. Since the communicating tube (15) is provided, when the water in the tank (12) is discharged to a space outside the hull (2), the pressure in the tank (12) at the bow side is maintained at atmospheric pressure. This facilitates the water discharge.

(22) In the case where the tank (12) is filled with water at the time of sailing, sailing performance deteriorates due to the increased sailing resistance. However, the tank (12) is empty at the time of sailing whereby there exists no factor of the increase of the sailing resistance. Although the amount corresponding to the increased weight of the top plate (13) and the communicating tube (15) becomes the factor of the sailing resistance as compared to the case where the boat does not include the anti-rocking device, the reinforcement of the hull (2) by the top plate (13) contributes to the improvement of the sailing performance, and the anti-rocking device (11) is prevented from acting as an impediment to the sailing of the boat (1). In addition, to discharge water from the tank (12) (and to introduce water into the tank (12)), no manpower is required, and therefore an operation to remove the impediment to the sailing is trouble-free.

(23) FIG. 6 to FIG. 8 show a boat, when moored, according to a second embodiment of the present invention.

(24) A boat (20) according to the second embodiment differs from the boat (1) according to the first embodiment in that an engine (26) is provided at the center in the right and left direction. The shape of the hull (2), including the longitudinal vertical plates (8) and (9), is the same as that of the first embodiment.

(25) The boat (20) as described above has the same structure of the conventional planing boat, but the planing boat (20) in accordance with the present invention further includes an anti-rocking device (21).

(26) The anti-rocking device (21) has right and left tanks (22) for storing water. Between upper ends of each pair of the two longitudinal vertical plates (8) and (9), each pair being provided at the right or left part of the boat (20), a top plate (23) is laid. Each of the two right and left pairs of longitudinal vertical plates (8) and (9), the top plate (23), a part of the bottom plate (5), a part of the transom plate (7), and a bow end portion of each of the right and left side plates (6) form an enclosed space to constitute a tank (22).

(27) The transom plate (7) has a through hole (24) that allows water (seawater or fresh water) to flow into/out of each of the tanks (22). Each through hole (24) is provided below the waterline (i.e., a water surface (H)) on the transom plate (7) (a wall on the stern side of each tank (22)). In addition, at the front end portion (bow side) of each tank (22), a communicating tube (25) that allows air to flow in and out of the tank (11) is provided.

(28) Therefore, to form the anti-rocking device (21), only the processes of placing the top plates (23), forming the through holes (24), and placing the communicating tubes (25) are required as additional processes.

(29) Although drawings corresponding to FIG. 4 and FIG. 5 of the first embodiment are omitted, also in the boat (20) according to the second embodiment, in the same manner as the boat (1) according to the first embodiment, the degree of the rocking of the boat (20) when moored is less than the conventional boat (P), the anti-rocking device (21) is prevented from acting as an impediments to the sailing of the boat (20), and, in addition, an operation to remove the impediment to the sailing is trouble-free.

(30) FIG. 9 shows a boat (when moored) according to a third embodiment of the present invention. The boat according to the third embodiment is configured by further including a lid (26) to the boat according to the first embodiment. In the case where rocking raises no problem, such as a case where the boat temporarily stops sailing and a case where the boat is moored at a port with no attendant, the through hole (14) may be closed using the lid (26) to prevent the water from flowing into the tank (12), when the speed is lowered and before the water flows in through the through hole (14). This prevents the growth of shellfish, algae, and so on within the tank even when the boat is moored over a long period of time, and this allows the boat (1) to be lightweight leading to smooth acceleration when the boat starts sailing again, which results in energy saving.

(31) FIG. 10 shows the boat (during the sailing) according to the third embodiment of the present invention. When the boat starts sailing and the sailing speed exceeds a certain value, the bow rises above the surface of the water and the boat starts pushing water away at an area behind the stern, as shown in FIG. 5. At this time, when the closed lid (26) is opened, the boat continues sailing with no water flowing through the through hole (14) into the tank (12).

(32) In the above embodiments, the longitudinal vertical plates (8) and (9) are not limited to those shown in the drawings, and the tank may be provided by using existing longitudinal vertical plates as appropriate. In addition, when required, any longitudinal material as a separate component may be added for forming the tank.

(33) This international application claims the benefit of priority of Japanese Patent Application No. 2014-234705 filed Nov. 19, 2014 on which the present application is based, and the entire disclosure of which is hereby incorporated by reference.

REFERENCE SIGNS LIST

(34) 1: boat 2: hull 5: bottom plate 6: side plate 7: transom plate 8, 9: longitudinal vertical plate 10: engine 11: anti-rocking device 12: tank 13: top plate 14: through hole 15: communicating tube 20: boat 21: anti-rocking device 22: tank 23: top plate 24: through hole 25: communicating tube 26: lid