JP2012011898A - Ship's bottom jacket structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ship's bottom jacket structure capable of developing the effect of suppressing frictional resistance to water over the relatively long section of a ship's bottom and capable of avoiding the status of increasing the frictional resistance to water.SOLUTION: The ship's bottom jacket structure includes a plurality of downward protruded plates 11 each having a downward protruded bent plate cross section curved or bent into a downward protruded shape and extending in the longitudinal direction of a ship, and continuously provided via connection parts 12 along the lower face of the ship's bottom B in the cross direction. The downward protruded plates 11 each have an air flow path 2 opening near the front end of the plate and extending between the plate upper face side and the ship's bottom B over in the longitudinal direction of the ship, and cut-out parts 4 formed by cutting out the plate cross section upward from its protruded lower part over the bottom part or both side parts of the plate to divide the air flow path 2 at a plurality of positions.

Description

  The present invention relates to a ship bottom jacket structure that can be mounted over a ship bottom.

  Conventionally, as a ship bottom structure that suppresses power loss caused by frictional resistance between the plate member on the ship bottom and water, a propulsion unit is arranged at the center in the width direction of the rear part of the hull, and a pair of left and right sides of the propulsion unit is positioned on the left and right sides of the propulsion unit In a small vessel to which a plate member is attached, a bottom structure is disclosed in which a gap is formed between the front end surface of the plate member and the hull, and the gap is opened to the side of the hull (see, for example, Patent Document 1). ).

  This is a small planing boat (small ship) in which a propulsion unit is arranged at the center in the width direction of the rear part of the hull, and a pair of left and right step plates (plate members) are attached to the bottom of the ship and are mounted on the bottom of the ship. A gap is formed between the front end face of each step plate and the hull (hull), and the gap is opened to the side of the hull. According to the present invention, the front end face of each step plate on the bottom of the ship Since the gap formed between the ship and the hull opens to the side of the hull, air in the atmosphere is sucked into the gap of the hull by the negative pressure generated in the gap when water flows through the bottom of the ship. To flow backward along the bottom of the step plate to eliminate water. As a result, the contact between the step plate and water is suppressed by air, and the loss power accompanying the frictional resistance between the step plate and water is suppressed to a small level.

  Conventionally, as a bottom structure of a planing boat that improves the sailing performance of a planing boat, there is a concave or convex surface having a minute concave or convex portion that allows air to be engulfed from the outside of the hull into part of the water contact surface at the bottom of the boat. What was formed is disclosed (for example, refer to Patent Document 2).

  This is because the air flow is separated from the ship bottom surface 20 by causing air from the outside of the hull to be brought into contact with the water contact surface S at the time of sliding on the bottom surface 20 of the planing boat by the uneven surface 21, thereby It is said that the frictional resistance is reduced.

JP 2001-97277 A JP 2000-272577 A

  However, in the bottom structure of the above-mentioned small boat or planing boat, there is a limit to the amount of air entrained between the bottom of the boat and the water, and the frictional resistance with water during acceleration towing or high-speed towing is limited to a relatively short section of the bottom of the ship. It was only a thing to suppress.

  Further, when the ship is towed at a low speed or turned, the uneven shape of the bottom of the ship may lead to an increase in frictional resistance with water, so that the effect of suppressing power loss cannot always be obtained.

  Therefore, in the present invention, the effect of suppressing the frictional resistance with water can be exhibited over a relatively long section of the ship bottom, and the situation in which the frictional resistance with water is increased by removing as necessary is avoided. It is an object of the present invention to provide a ship bottom jacket structure that can be used.

In order to solve the above problems, the present invention takes the following measures.
(1) The ship bottom jacket structure of the present invention comprises a jacket body that can be detachably covered and fixed along the bottom of the ship from the front of the ship B to the horizontal part of the ship bottom.
In this jacket body, a plurality of lower convex plates 11 having a downward convex curved plate section curved or bent downward and extending in the front-rear direction of the ship are connected to the connecting portion 12 along the lower surface of the bottom B. It is connected in the width direction through,
Each lower convex plate 11 opens between the front end of the plate and the ship bottom B, and from this opening, the air flow path 2 extending in the front-rear direction of the ship extends between the plate upper surface side and the ship bottom B,
A plurality of cutout portions in which the air flow path 2 is divided at a plurality of locations by notching the width direction of the lower projection plate 11 upward from the convex lower portion over a plurality of locations on the bottom or both sides of each downward projection plate 11. 4
When the hull B is towed, the air flow taken in from the opening flows through the air flow path 2 and is discharged from the cutout portion 4 to the outside lower side to the side of the lower convex plate 11, thereby causing the downward convexity. An air layer is formed on the lower surface or the outer surface of the plate 11.

  Actually, when the hull B starts to move, the air in the air flow path 2 is continuously discharged as bubbles from the notch 4 around the lower surface of the lower convex plate 11. By flowing and moving around the plate surface over almost the entire area in the vertical direction, the frictional resistance with water can be reliably reduced even if there is an uneven shape.

  The lower convex plate 11 is a plate that is bent downward in a front view or a rear view, and is spaced apart in the width direction so as to be adjacent to each other between the outsides of the adjacent lower convex plates 11. A separating portion 3 that is formed in a convex shape and extends in the front-rear direction of the ship appears. That is, when viewed from the bottom of the ship, the separation portions 3 and the lower convex plates 11 that extend in the front-rear direction of the ship are alternately connected in the width direction (see, for example, FIG. 1). The upper edge of the spacing portion 3 is composed of a connecting portion 12 extending in the front-rear direction with a constant width, and an air flow path 2 extending in the front-rear direction with a constant width is formed between the upper portion of the lower convex plate 11 and the bottom of the ship. .

  For example, in the form of Embodiment 1 (FIGS. 1 to 4), which will be described later, the airflow discharged along the outer peripheral surface of the lower convex plate 11 from the notch 4 of the lower convex plate 11 becomes a bubble and is separated from the gap. By gathering in the part 3 and forming an air layer in the separated part 3, the frictional resistance generated between the bottom of the traveling ship and the water is reduced.

  (2) It is preferable that the notch 4 is formed by notching the lower convex end of the lower convex plate 11 in the width direction, and by notching the side portion of the lower convex plate 11 obliquely forward and upward from both ends. . That is, the cutout direction of the cutout portion 4 is not obliquely downward from the upper connecting plate 12 but is directed obliquely rearward and downward, and the convex end surface of the lower convex plate 11 is cut in the width direction at the lower end (for example, FIG. 3).

  With such a configuration, the airflow from the air flow path 2 to the outer surface of the lower convex plate 11 is smoothly discharged, and water does not easily enter the air flow path 2 through the notch portion 4. Further, since the air once discharged to the outer surface side of the lower convex plate 11 then circulates to the left and right side portions of the lower convex plate 11, the air is not introduced again into the air flow path 2 inside the lower convex plate 11, but the connecting plate 12. It is discharged to the rear end of the ship bottom jacket structure along the bottom surface. Thereby, reduction of friction resistance can be aimed at continuously over the comparatively long area over the full length of the draft part of a ship.

(3) The notch 4 is formed by cutting a cut piece of a predetermined distance in the lengthwise direction of the lower convex plate 11 so that the first opening and the second opening are separated from each other in the front-rear direction. And
By forming the narrowed portion 11R in which the lower convex plate 11 at the periphery of the second opening is narrowed in the height direction and the width direction, the rear second opening 20R is the front first opening in the front view. It is preferable that the first opening 20F is formed within an area smaller than 20F.

  By doing in this way, it is difficult for water from the outside to enter the second opening 20R, and the exhaust air from the air flow path 2 flows from the first opening 20F to the lower convex plate 11 outside the second opening 20R. It becomes easy to discharge along the outer periphery. For example, the length of the side rear side 43R and the length of the bottom rear side 41R by the notch 4 are formed to be smaller than the length of the side front side 43F and the length of the bottom front side 41F, respectively.

  (4) The lower convex plate 11 is composed of a bottom plate formed substantially horizontally below the ship bottom B, and side plates 13 that are bent from both ends of the bottom plate and expand obliquely in cross-sectional view. The notches 4 are formed at equal intervals over the entire height direction, and the side plates 13 of the adjacent lower convex plates 11 are connected to each other by a top plate formed in the vicinity of the ship bottom B and substantially horizontally. It is preferable that the parts 12 are connected. This specifies the form of Example 1 which consists of a bent board with a cross-sectional continuous bowl-like shape as the entire ship bottom jacket structure.

  If the bottom rectangular jacket-shaped connecting portion 12 is formed into a continuous bottom in the width direction, even if a large number of notches 4 are formed, the connecting portion 12 can ensure appropriate rigidity. In particular, the connecting portion 12 is made of an elastic plate that bends along the bottom of the ship and is fixed in contact with the surface, so that the fixing property of the connecting portion 12 to the bottom of the ship can be improved and the bottom jacket structure is fixed to the ship. In addition, it is difficult to easily shift or come off.

  (5) The lower convex plate 11 is composed of a curved plate that is curved below the ship bottom B in a semicircular cross section, and the upper ends of adjacent lower convex plates 11 are close to each other, and from the bent portion protruding upward. It is preferable that the connecting portion 12 is connected. This specifies the form of Example 2 which consists of a curved board with a continuous semicircular cross section as the entire ship bottom jacket structure.

  In this case, the air exhausted from the air flow path 2 is dispersed along the outer peripheral side surface of the lower convex plate 11 behind the notch 4 by forming the notch 4 along the curved surface. The air layer can be easily formed on the entire outer peripheral side surface of the lower convex plate 11 easily.

  For example, as shown in Example 2 (FIG. 5), which will be described later, the connecting portion 12 has an inverted U shape in which the bent inner surfaces are in surface contact with each other, and the raw material made of an integral flat plate has a width. It is formed by bending in the direction, and the notch width 4D of the notch 4 increases as it goes from the upper part to the lower part of the lower convex plate 11.

  By taking the above measures, air enters and exits through the plurality of notches that divide the lower convex plate and the air flow path, so that the lower convex plate formed in the longitudinal direction extends around a relatively large section. In this way, bubbles consisting of an air layer are automatically generated, and the effect of suppressing frictional resistance with water can be exerted over a relatively long section of the ship bottom.

  Moreover, it became a thing which can avoid the situation where the frictional resistance with water increases by setting it as the structure which can be removed as needed.

FIG. 1 is a bottom view showing a state in which a ship bottom jacket structure of Example 1 is mounted. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is an enlarged view of the part α in FIG. FIG. 4 is a partially broken enlarged perspective view of the ship bottom jacket structure of the first embodiment. FIG. 5 is a partially broken enlarged perspective view of the ship bottom jacket structure of the second embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described together with respective drawings shown as examples. The ship bottom jacket structure of the present invention basically comprises a jacket body that removably covers and fixes at least a part of the ship bottom B forward and above the waterline K along the ship bottom.
In this jacket body, a plurality of lower convex plates 11 having a downward convex curved plate section curved or bent downward in a convex manner and extending in the front-rear direction of the ship have connecting portions 12 along the lower surface of the bottom B. Through the width direction.

The lower convex plate 11 is opened near the front end of the plate and extends between the plate upper surface side and the ship bottom B in the front-rear direction of the ship,
The plate has a notch portion 4 that cuts the plate cross-section upward from the convex lower portion and cuts the air flow path 2 at a plurality of locations across the bottom or both sides of the plate.

  When the ship is towed with the ship bottom jacket structure attached, the air flow taken in from the opening flows through the air flow path 2 and is discharged from the notch 4 to the outside downward or side of the lower convex plate 11. Thus, bubbles are generated around the lower surface of the lower convex plate 11, and the frictional resistance of water is suppressed. Hereinafter, the configuration of each embodiment will be described in detail.

  In the ship bottom jacket structure of the first embodiment shown in FIGS. 1 to 4, the lower convex plate 11 is a plate bent downward in a convex shape, and is adjacent to the adjacent lower convex plate 11 by being spaced apart in the width direction. A space 3 is formed between the outsides, and the outer edge has an inverted U-shaped cross section. The airflow discharged from the cutout portion 4 of the lower convex plate 11 along the outer peripheral surface of the lower convex plate 11 is foamed and gathers in the separation portion 3, and an air layer is formed in the separation portion 3. The frictional resistance generated between the ship bottom B moving in the water and the water is reduced (see the arrow in FIG. 2).

(Downward convex plate 11)
The lower convex plate 11 is composed of a bottom plate formed substantially horizontally below the ship bottom B and side plates 13 that are bent from both ends of the bottom plate and are formed in an oblique direction in cross section, and are adjacent lower convex plates. It is preferable that the 11 side plates 13 are connected to each other by a connecting portion 12 made of a top plate that is formed in the vicinity of the ship bottom B and is substantially horizontal. This is because the hull jacket structure as a whole uses a bent plate having a continuous cross-sectional shape and reduces the frictional resistance with water by allowing air to enter the U-shaped space that is alternately continuous.

(Notch 4)
The notch 4 is formed by notching the lower convex plate 11 obliquely forward upward from the convex lower part in a side view. In the first embodiment, the cutout portion 4 cuts the lower convex plate 11 from a cut piece having a predetermined length direction distance, and the cutout width 4D is formed by cutting the first opening portion and the second opening portion back and forth. Are spaced apart from each other.

  Specifically, a part of the lower surface plate 11 is cut off at the lower surface of the lower convex plate 11 with a predetermined notch width 4D in the front-rear direction, and the side rear portion is formed on both side surfaces of the lower convex plate 11. The side 43R and the side front side 43F intersect at each upper end. The lower ends of the side rear side 43R and the side front side 43F are spaced apart by the width of the cutout width 4D and open downward (FIG. 4).

The side front side 43F and the side rear side 43R are formed not in a vertically upward direction but in an inclined direction in which the upper end approaches the front side. Forming an angle theta ₁ from the front lower surface of the side front sides 43F less than 90 degrees, preferably not more than 85 degrees 60 degrees, the angle formed theta ₂ from the rear underside of the side after side 43R 90 degrees greater, Preferably, it is 95 degrees or more and less than 120 degrees. It is preferable that the angle of the front side of the side and the angle of the rear side of the side are the same, that is, parallel in a side view, that is, with the same notch width 4D.

  However, as another form, the notch width 4 </ b> D may be variable in the height direction of the lower convex plate 11 in accordance with the discharge amount of the airflow from the ventilation path 2. For example, if the cutout width 4D is increased as it goes downward, the gas is efficiently discharged from the air passage 2.

  Conversely, for example, if the cutout width 4D is formed so as to decrease downward, the inflow of water from the second opening 20R surrounded by the side rear side 43R into the ventilation path 2 is suppressed. In this embodiment, the inclination angle difference as viewed from the vertical direction is smaller on the side rear side than on the side front side. That is, it opens wide downwards, and the opening width in side view decreases as it goes upward. If it is such, the discharge | emission of the airflow from the inside of the air flow path 2 to the outer surface of the downward convex board 11 will be performed smoothly. Further, part of the air once discharged to the outer surface side of the lower convex plate 11 is again introduced into the air flow path 2 inside the lower convex plate 11 from the side front side. Thereby, reduction of frictional resistance can be aimed at continuously over a comparatively long front-back direction area.

  Further, in the first embodiment, the rear bottom surface and side surface of the notch formed by the notch portion 4 are inclined surfaces 11R and inclined side surfaces 13R narrowed toward the inner side of the air flow path 2, and a pyramid having an enlarged cross section forward toward the notch portion. It has a planar shape (FIG. 3). By the narrowed portion composed of the inclined surface 11R and the inclined side surface 13R, a narrowed portion is formed by narrowing the lower convex plate 11 at the periphery of the second opening portion in the height direction and the width direction. The rear second opening 20R surrounded by the side surface 13R is formed in the range of the first opening 20F in an area smaller than the front first opening 20F in a front view.

(Overhanging piece 14)
Overhanging pieces 14 are provided along both sides of the ship bottom jacket structure. As shown in FIG. 4, the projecting piece 14 on each side is located in a bent portion from the bottom of the hull to the side of the ship, and is obliquely downward as viewed from the front (in the embodiment, 45 degrees obliquely downward when attached to the ship). It is an overhanging plate piece. The upper end of the overhanging piece 14 is bent at an angle of 45 degrees outward and downward from the outer end of the connecting portion 12 formed at the outermost end portion, and linearly protrudes in the downward inclined direction with respect to the connecting portion. The air escaping upward from the air passage 21 gathers on the lower surface of the projecting piece 14 or the lower surface of the connecting portion 12 at the outermost end portion, and reduces the frictional resistance with water on the ship bottom side portion. Further, since the overhanging piece 14 projects obliquely downward from the hull in the state of being attached to the bottom of the ship and extends in a plane shape in the entire front-rear direction of the drafting portion of the ship, the wave-making resistance can also be reduced.

(Bottom front side 41F)
As shown in FIGS. 3 and 4, the bottom front side 41 </ b> F is bent downward to expand the lower end of the first opening 20 </ b> F downward.

(Aperture difference)
As shown in FIG. 3, a minute opening difference portion at a height of 4H opens rearward as a portion of the opening difference between the first opening 20F and the second opening 20R. The opening difference height 4H is preferably formed within a range of about half of the cutout width 4D or about the same. For example, when the notch width 4D is an average notch total length of 2.0 mm, the opening difference height 4H is 1.0 mm (half the notch width 4D) near the both ends of the bottom front side 41F, and the bottom front It is preferably 2.0 mm (same as the notch width 4D) in the vicinity of the side center of the side 41F.

  The airflow from the air flow path 2 is discharged to the rear from the opening difference portion. At this time, the airflow that has exited the opening difference portion is sprayed due to the spray effect and is scattered around the rear second opening portion 20R, and spreads around the bottom rear side 41R and the side rear side 13R of the lower convex plate 11. And flow backwards.

(Mounting part)
As an attachment portion as a jacket structure, a locking tool 51 is formed apart along the side of the jacket body. A rope 52 is fastened to the lock 51, and a hook 53 to the side edge of the ship is fastened to the tip of the rope 52. Alternatively, the locking hook 53 is locked directly to the locking tool 51. The locking device of the embodiment is composed of a circular ring device, and a locking hook 53 ′ with a tightening bolt 54 is connected to the front and rear locking devices 51, thereby enabling locking with the helicopter of the ship body. The other locking tool 51 is connected to a locking hook 53 made of a bent plate (FIG. 2).

  The state of attachment to the ship bottom of the present invention can also be released by releasing the hook of the attachment portion. By attaching or removing the bottom jacket of the present invention as necessary, it is possible to cope with long-term navigation, or it is possible to easily cope with maintenance of the bottom of the ship, replacement of the bottom jacket structure itself, and repair. it can.

  The lower convex plate 11 of the second embodiment shown in FIG. 5 is formed of a curved plate that is curved below the ship bottom B in a semicircular cross section, and the upper ends of adjacent lower convex plates 11 are close to each other, It is preferable to be connected by a connecting portion 12 including a protruding bent portion. This is because the hull jacket structure as a whole uses a curved plate having a semicircular cross section in cross section, and the spacing portion 3 is formed between adjacent convex surfaces and is composed of a mountain-shaped cross-sectional space converged upward. Compared with Example 1, the air layer is easily formed thicker in the height direction in the separation portion 3, and the effect of reducing the frictional resistance in the outer portion of the lower convex plate can be enhanced.

  Further, the cutout portion 4 of the second embodiment is formed such that the side front side 43F and the side rear side 43R are each formed in a curved line shape. A closed cutout 4 is formed. The notch width 4D of the notch 4 increases as it goes from the upper part of the lower convex plate 11 to the lower part.

The connecting portion 12 of Example 2 has an inverted U shape in which the bent inner surfaces are in surface contact with each other by bending upward, and is formed by bending a raw material made of an integral flat plate in the width direction,
The embodiment of the present invention has the above-described configurations. However, the present invention is not limited to the above-described embodiments, and components are appropriately extracted, replaced, modified, and elements without departing from the spirit of the invention. It is possible to change the shape including the omission or the size ratio.

11 Lower convex plate 12 Connecting portion 13 Side plate 2 Air flow path 3 Separating portion 4 Notch portion 4D Notch width 4H Opening difference height 41F Bottom front side 41R Bottom rear side 43F Side front side 43R Side rear side θF Side portion Formation angle θR of the front side 43F Formation angle B of the side rear side 43R B

Claims (5)

It consists of a jacket body that can be removably covered and fixed along the bottom of the ship bottom (B) from at least the front of the waterline to the horizontal bottom of the ship bottom (B),
In this jacket body, a plurality of downward convex plates (11) having a downward convex curved plate section curved or bent downward and extending in the front-rear direction of the ship are formed on the bottom surface of the ship bottom (B). It is connected in the width direction via the connecting part (12) along,
Each downward convex plate (11) has an air flow path (2) extending in the front-rear direction of the ship between the plate upper surface side and the ship bottom (B) while the vicinity of the front end of the plate opens between the ship bottom (B). Form the
A plurality of notches (4) are formed by notching the width direction of the lower convex plate (11) upward from the convex lower portion over a plurality of locations on the bottom or both sides of each lower convex plate (11),
As the ship navigates, the air flow taken in from the opening flows through the air flow path (2) and is discharged from the notch (4) to the outside downward or side of the lower convex plate (11). Thus, an air layer is formed on the lower surface or the outer surface of the lower convex plate (11).   The notch (4) is formed by notching the lower convex tip of the lower convex plate (11) in the width direction, and notching the side portion of the lower convex plate (11) diagonally forward and upward from both ends. The ship bottom jacket structure according to claim 1. The notch (4) is formed by cutting the lower convex plate (11) into a cut piece having a predetermined distance in the length direction, so that the first opening (20F) and the second opening (20R) move back and forth. Are arranged opposite to each other,
By forming the lower convex plate (11) at the periphery of the second opening (20R) in the height direction and the width direction, the second opening (20R) is formed in the first opening (20F) in front view. 3) The ship bottom jacket structure according to claim 1 or 2, which is formed within an area smaller than the first opening (20F).   The lower convex plate (11) is composed of a bottom plate formed substantially horizontally below the ship bottom (B), and side plates (13) bent from both ends of the bottom plate and extending obliquely in cross-sectional view, The notches (4) are formed at equal intervals over the entire height direction of the side plate (13), and the side plates (13) of the adjacent lower convex plates (11) are close to the ship bottom (B). The ship bottom jacket structure according to any one of claims 1, 2, and 3, wherein the ship is connected by a connecting portion (12) comprising a top plate formed substantially horizontally.   The lower convex plate (11) is composed of a curved plate formed in a semicircular cross section below the ship bottom (B), and the upper ends of adjacent lower convex plates (11) are close to each other and protrude upward. The ship bottom jacket structure according to any one of claims 1 to 3, wherein the ship bottom jacket structure is connected by a connecting portion (12) comprising a bent portion.

Images