JP3245023B2 - Bottom structure of water jet propulsion boat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bottom structure of a water jet propulsion boat such as a water jet propulsion boat.

[0002]

2. Description of the Related Art In recent years, a water jet propulsion boat equipped with a water jet propulsion machine, which glides at high speed at sea and performs various operations such as sudden turning and sudden stopping, has been widely used. In some cases, the ship may perform an operation of jumping by lifting the bow during high speed gliding.

[0003]

In the hull having the above construction, the bottom plate is formed as a continuous surface from the bow to the stern end (a curved surface in the width direction of the ship). When jumping by lifting the part, it is necessary to make the bottom of the stern part deeply submerged in the water, and there is a problem that it is difficult to sufficiently lift the bow part to perform a sufficient jump because of its large resistance. For this reason, it is conceivable to provide a stepper on the stern bottom portion, which is a surface located above the front bottom. In order to make a sufficient jump, it is desirable that the step between the stepper and the ship bottom in front of the stepper is large. Here, if the length of the stepper in the hull length direction is increased, when the hull oscillates (pitches) in the front-rear direction at the time of cruising, the same effect as when the hull length is reduced occurs, and pitching is performed. Becomes large. On the other hand, if the length of the stepper in the hull length direction is shortened, a large jump cannot be made because the stern-side end of the bottom at the front side of the stepper sinks deeply into the water when trying to lift the bow.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional drawback, and a water jet propulsion in which a bow is largely lifted so that a large jump can be made and large pitching is hardly generated. It is an object of the present invention to provide a boat bottom structure.

[0005]

According to the first aspect of the present invention, there is provided a water jet propulsion boat in which a jet propulsion unit is installed at a stern bottom behind a water introduction port for a jet propulsion unit which opens at the bottom of the stern. A first stepper formed of a surface located above the front bottom of the first stepper, and a second bottom formed of a surface located above the first stepper at the stern end on the rear bottom of the first stepper. A stepper is formed.

In the above configuration, the first stepper and the second stepper formed on the stern bottom behind the water inlet for the jet propulsion opening to the bottom of the ship make the bottom gradually increase as approaching the stern end. Therefore, the second stepper is separated from the bottom of the ship in front of the first stepper by a large amount. Also, although the amount by which the first stepper separates above the ship bottom on the front side thereof is smaller than that of the second stepper, when the bow is lifted, the amount by which the ship bottom sinks in the water as it moves further forward from the stern end. Therefore, the first stepper does not submerge so much when the bow is greatly lifted, and the position of the first stepper is raised to the position of the second stepper, that is, the first stepper is moved from the front end of the first stepper to the second stepper. The same effect can be obtained as if the rear end of the two steppers is formed on the same plane, which is largely separated upward from the ship bottom on the front side of the first stepper. Therefore, when the bow is lifted during the voyage and the jump is performed, the bottom of the stern end composed of the first stepper and the second stepper does not sink deeply into the water. Can be performed.

Further, since the first stepper is located lower than the second stepper, if the hull sways in the longitudinal direction during cruising, the position of the first stepper is raised to the position of the second stepper. In this case, the rear end of the first stepper is immersed in the water at a time when the swing is small as compared with the case described above, thereby preventing the pitching from becoming large.

According to a second aspect of the present invention, the size of the step between the first stepper and the ship bottom on the front side thereof is equal to that of the first stepper and the second stepper.
It is set smaller than the size of the step between the stepper.

In the above configuration, when the hull sways in the front-rear direction at the time of sailing, the rear end of the first stepper is immersed in the water at a time when the sway is small, and the pitching is reliably prevented from increasing. Is done.

According to a third aspect of the present invention, a drain plug is provided on a front wall of the second stepper between the first stepper and the second stepper.

In the above configuration, the space can be effectively used by installing the drain plug on the wall between the first stepper and the second stepper.

According to a fourth aspect of the present invention, the width of the second stepper is set smaller than the width of the first stepper.

According to the above configuration, it is possible to easily make a sudden turn by sliding the stern portion sideways.

According to a fifth aspect of the present invention, the front wall of the second stepper and the first stepper between the first stepper and the second stepper are joined at substantially right angles, and the second stepper and the stern plate are curved. They are joined via a surface.

In the above configuration, the size of the step between the first stepper and the ship bottom on the front side thereof is set smaller than the size of the step between the first stepper and the second stepper. It is conceivable that the water cut at the rear edge of the bottom of the ship scatters upward and hits the rear end of the first stepper, but the second stepper front wall and the first stepper between the first stepper and the second stepper are considered. Are joined at substantially right angles, so that the water applied to the rear end of the first stepper is reliably cut off at the rear edge of the first stepper. Therefore, in combination with the large separation of the second stepper from the first stepper, the splashed water is prevented from hitting the second stepper, and the jump is performed smoothly. On the other hand, since the second stepper and the stern plate are joined via the curved surface, even if the rear end of the second stepper tries to submerge in the water when the bow is lifted, it is formed on the curved surface. Since it is formed, it can be smoothly immersed in the water without being caught on the water surface. With such a configuration and operation, a jump can be smoothly performed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 4, a hull 1 of a small boat is provided with an operation handle 20 on a hull center line near the center thereof, and a driver's seat seat extending rearward in a stern direction. 2 and a rear seat 21 are provided, and on both sides thereof, a foot deck 30 on which the person on the seats 2 and 21 puts a foot is formed. A storage box 80 is disposed below the rear seat 21, and the rear seat 21 functions as a lid of the storage box 80, and the upper opening of the storage box 80 can be opened by removing the rear seat 21. Like that.

On the lower front side of the driver's seat 2, a fuel cock 73 and an air intake (through hole) 74 for taking in air into the hull are formed. The fuel cock 73 is operated by a driver straddling the seat 2, but since an air intake 74 is formed near the fuel cock 73, there is always an air flow in this portion. Therefore, there is an advantage that the fuel cock 73 is easy to dry even if it is splashed with water, and is easy to operate.

Also, as shown in FIG. 3, inside the bow,
A bow deck 7 is formed, and this bow deck 7 is formed in a V-shaped side shape so that the center in the longitudinal direction of the ship is high, and a bow storage 71 is formed from the highest portion to a forward inclined portion on the front side.
And an air intake duct 72. The upper side of the bow deck 7 is covered with a bow deck cover 76 and a storage case cover 75. Since the bow deck 7 is formed not in a flat shape but in a V-shape, the strength against a downward load is large and the area of the deck surface of the bow deck 7 is increased. There is also an advantage that the air intake duct 72 can be easily installed. Also, a flat U-shaped grip member 8 is attached so as to cover both sides and the rear base of the rear seat 21, and when an underwater person gets on the board from the stern end, the rear end of the grip member 8 is gripped. Like that.

An engine 5 is installed in the center of the hull, near the center in the longitudinal direction on the hull center line, and a water jet propulsion device 4 extending to the stern end is installed on the rear side. The shaft of the impeller rotating inside the machine 4 is connected to the drive shaft of the engine 5. The water jet propulsion device 4 is disposed in a stern casing (stern pump room) 44 having a rear portion opening at the stern end. The rear portion of the jet water jet propulsion device 4 extends in the stern pump room 44 to the stern end, and has a rear end. The portion is provided with a steering nozzle and a reverse bucket 41. The water jet propulsion device 4 also has a water inlet 42 that opens to the bottom of the ship, and water is introduced from the water inlet 42 by rotation of the impeller.
The propulsion force and the turning force are generated on the hull by injecting water in a predetermined backward direction from the water injection port 41 at the stern.

Exhaust expansion chambers 51 of the engine are arranged on one side of the engine 5 respectively, and a first exhaust pipe (hose) 59 led out therefrom has a water jet propulsion device 4 and a stern. The water pump 52 is connected to a water lock 52 disposed on one side of the pump chamber 44, and a second exhaust pipe 53 from the water lock 52 extends upward on the hull center line and then curves to be oblique from above the stern pump chamber 44. It extends rearward and downward (formed in an inverted U-shape), and is connected to a wall 45 formed obliquely upward and forward at the upper front end of the stern pump chamber 44 and opens into the stern pump chamber 44. Since the wall 45 is formed obliquely upward and forward, the distal end of the second exhaust pipe 53 formed in an inverted U-shape does not need to be further curved at a portion where it is connected to the stern pump chamber 44, and the piping can be easily handled. Has become.

A stern pump chamber 44 in which the rear of the water jet propulsion device 4 is disposed at the center in the width direction of the stern is formed on the stern bottom. A stepper 61 is formed, and a second stepper 62 having a smaller width and a higher height than the first stepper 61 is formed at the stern end on the rear side of the first stepper 61, and the rear end of the second stepper 62 is formed. The stern plate (transom) 66 is continuous via a curved surface. The length A of the first stepper 61 in the hull length direction is substantially the same as the length B of the first stepper 61 in the hull length direction, and the size of the step of the second stepper 62 (of the second stepper 62) Height C of front wall 620)
Is set larger than the size of the step of the first stepper (the height D of the front wall 610 of the first stepper 61). An impeller-type speed sensor 64 is attached to the rear end of the first stepper 61, and a front wall 62 of the second stepper 62 is provided.
A drain plug 63 is attached to 0. Further, both the first stepper 61 and the second stepper 62 are inclined so as to be located upward as going outward in the boat width direction.

A bottom plate 13 made of an aluminum alloy is mounted between the first steppers 61 on both sides, thereby covering the water jet propulsion device 4 accommodated in the pump chamber 44 from below. The bottom plate 13 has an inclined surface 6 having both side ends formed on the inner end of the first stepper 61.
The bottom surface is formed in a horizontal plane connecting the ridge lines 612 on both sides. The rear edge of the ship bottom plate 13 coincides with the rear edge of the first stepper 61 in bottom view, but extends to the rear edge of the second stepper 62, thereby protecting the rear portion of the water jet propulsion device. You may make it.

A sponson 9 is mounted on the stern side of the ship, and the sponson 9 is configured as shown in FIGS. That is, the sponson 9 is composed of a main body 90 and a mounting member 91. The mounting member 91 has a plurality of (two in this example) support pins 92 on a long and thin plate material mounted on the ship side plate at predetermined intervals in the length direction of the hull. The sponson main body 90 is formed in a semi-cylindrical shape elongated in the lengthwise direction of the ship, and has a bow side tapered. The main body 90 has a fitting hole 93 formed at a position corresponding to each support pin 92. Each has an adjustment nut 94
Is inserted. This adjust nut 9
No. 4 has a flange 942 formed at one end of the cylindrical body, a projection 944 for operation formed at the end face thereof, and an axial through hole 940 eccentric from the axial center of the adjust nut 94. Formed at the location. The through-hole 940 is formed to have a size that allows the collar 941 to be inserted through the support pin 92 in a state where the collar 941 is externally inserted. The adjustment nut 94 is inserted into the insertion hole 93 of the main body 90 so that the flange 942 is inserted into the insertion hole. The support pin 92 is brought into contact with the step portion 932, and the washer 922 is inserted into the through hole 940.
And the nut 921 to tighten the main body 90
Is fixed to the mounting member 91.

When the adjusting nut 94 is rotated around the support pin 92 with respect to the fitting hole 93 when the adjusting nut 94 is fitted into the fitting hole 93 of the main body 90, the adjusting nut 94 is formed eccentrically with respect to the supporting pin 92. The position of the adjustment nut 94 changes within the fitting hole 93.
By appropriately rotating the adjust nut 94, the main body 90 moves up and down and back and forth with respect to the support pin 92, and the mounting state of the main body 90 to the mounting member 91 fixedly mounted to the ship side plate (mounting state) Position) can be changed.

When the adjustment nut 94 at one end (for example, the end on the stern side) is adjusted as described above to change the position of one end of the main body 90 with respect to the mounting member 91, the other fitting hole is formed. Since the position of the support pin 92 within 93 is also affected, the other adjustment nut 94
It is also necessary to adjust the position in the fitting hole 93 in response to this change. In this embodiment, both adjust nuts 94 have the same shape. For example, the adjust nut at the bow side end does not have an eccentric through hole 940 but passes through the center of the shaft and passes through the main body 90. By forming an elongated through hole in the length direction and rotating the adjustment nut 94 on the stern side, the stern side end of the main body 90 is moved up and down and in the front and rear direction, and the bow side end is mainly in the front and rear direction. The adjustment may be performed such that only the movement is performed.

FIGS. 7 and 8 show another embodiment of the sponson, in which the construction of the mounting member 91 is the same as that described above, but the body 90 has one adjusting hole 95 and one through hole 96. Are formed. The adjustment hole 95 is elongated in the up-down direction and curved so as to draw an arc locus having the other through hole 96 as a center of curvature. In this configuration, in a state where the bow-side support pin 92 is passed through the through hole 96 via the collar 941, the stern-side support pin 92 is changed vertically in the adjustment hole 95 so that the penetrating position is changed. The stern end of the main body 90 is vertically displaced about the through hole 96 and is fixed by tightening and displacing. Thus, in this example, the position adjustment for vertically displacing the stern end of the main body 90 can be performed.

As described above, the adjustment of the mounting position of the sponson 9 can be easily performed by adjusting the nut 921. Therefore, for example, in the case of a single person, the mounting position of the sponson 9 is lowered, and in the case of a three-person embarkation. Time is Sponson 9
The mounting position of the sponson 9 can be set to the most preferable state according to the number of occupants, for example, by increasing the mounting position of the sponson.

In the above configuration, when the driver lifts the bow from the sliding state of the hull 1, only the stern comes into contact with the water surface 100 as shown in FIG. The stern also jumps away from the water surface 100. The bottom 11 does not extend to the stern end, and the first stepper 61 and the second stepper 62 sequentially increase the bottom, so that the second
The stepper 62 is separated upward from the bottom of the ship in front of the first stepper 61. Also, although the amount by which the first stepper separates above the ship bottom on the front side thereof is smaller than that of the second stepper, when the bow is lifted, the amount by which the ship bottom sinks in the water as it moves further forward from the stern end. When the bow is greatly lifted, the first
The stepper does not sink so much in the water, and the same effect as when the position of the first stepper is raised to the position of the second stepper can be obtained. Therefore, when the bow is lifted during the voyage and the jump is performed, the bottom of the stern end composed of the first stepper and the second stepper does not sink deeply into the water. Can be performed.

Since the first stepper is located below the second stepper, when the hull sways in the front-rear direction during cruising, the position of the first stepper is raised to the position of the second stepper. In this case, the rear end of the first stepper is immersed in the water at a time when the swing is small as compared with the case described above, thereby preventing the pitching from becoming large.

Further, when the hull sways in the front-rear direction at the time of sailing, the rear end of the first stepper is immersed in the water at a time when the sway is smaller, and the pitching is reliably prevented from increasing. . Further, by installing the drain plug on the wall between the first stepper and the second stepper, it is possible to effectively use the space. Further, by setting the width of the second stepper to be smaller than the width of the first stepper, it is possible to easily make a stern portion skid and make a sharp turn.

Further, the size of the step between the first stepper and the bottom on the front side thereof is set smaller than the size of the step between the first stepper and the second stepper. It is conceivable that the water cut off at the rear edge scatters upward and hits the rear end of the first stepper. However, the front wall of the second stepper and the first stepper between the first stepper and the second stepper are considered. Because they are joined at almost right angles, the first
The scattered water is reliably cut off at the rear end of the first stepper at the rear end of the stepper. Therefore, in combination with the second stepper being largely separated upward from the first stepper, the splashed water is prevented from hitting the second stepper,
Jumps are performed smoothly. On the other hand, since the second stepper and the stern plate are joined via the curved surface, even if the rear end of the second stepper tries to submerge in the water when the bow is lifted, it is formed on the curved surface. Because it is formed,
This can be immersed smoothly in the water without being caught on the water surface. As a result, the jump can be performed smoothly.

The overturn of the hull 1 causes the second exhaust pipe 53
Water enters the water lock 52 from the inverted U-shaped top of the second exhaust pipe 53 due to the restoration of the hull 1, and the remaining water is again discharged into the stern casing 44. Further, the water that has entered the water lock 52 accumulates inside the water lock 52, and is prevented from entering the engine 5. Moreover, since the second exhaust pipe 53 is formed in an inverted U-shape, an effect of preventing water from entering is achieved also in this portion.

[0033]

According to the first aspect of the present invention, the first stepper and the second stepper formed at the stern bottom behind the water inlet for the jet propulsion opening at the bottom of the stern gradually raise the bottom as approaching the stern end. As a result, the second stepper is separated from the ship bottom in front of the first stepper by a large amount. Also, although the amount by which the first stepper separates above the ship bottom on the front side thereof is smaller than that of the second stepper, when the bow is lifted, the amount by which the ship bottom sinks in the water as it moves further forward from the stern end. When the bow is greatly lifted, the first stepper does not submerge so much in the water, and the position of the first stepper is raised to the position of the second stepper, that is,
The same effect can be obtained as when the front end of the first stepper and the rear end of the second stepper are formed on the same plane which is largely separated upward from the bottom of the ship on the front side of the first stepper. Therefore, when the bow is lifted during the voyage and the jump is performed, the bottom of the stern end composed of the first stepper and the second stepper does not sink deeply into the water. Can be performed.

Further, since the first stepper is located below the second stepper, when the hull sways in the longitudinal direction during cruising, the position of the first stepper is raised to the position of the second stepper. In this case, the rear end of the first stepper is immersed in the water at a time when the swing is small as compared with the case described above, thereby preventing the pitching from becoming large.

According to the second aspect of the present invention, when the hull sways in the front-rear direction at the time of cruising, the rear end of the first stepper may be immersed in water at a time when the sway is smaller, resulting in increased pitching. It is surely prevented.

According to the third aspect of the present invention, the first stepper and the second stepper
By installing the drain plug on the wall between the stepper and the wall, effective use of space can be achieved.

According to the fourth aspect of the present invention, it is possible to easily make a sudden turn by sliding the stern portion sideways.

According to the fifth aspect of the present invention, the size of the step between the first stepper and the ship bottom on the front side thereof is set smaller than the size of the step between the first stepper and the second stepper. It is conceivable that the water cut off at the rear edge of the bottom of the shipboard on the front side of the stepper scatters upward and hits the rear end of the first stepper, but the second stepper front wall between the first stepper and the second stepper has Since the first stepper and the first stepper are joined at substantially right angles, the water applied to the rear end of the first stepper is surely cut off at the rear edge of the first stepper. Therefore, in combination with the large separation of the second stepper from the first stepper, the splashed water is prevented from hitting the second stepper, and the jump is performed smoothly. On the other hand, the second
Since the stepper and the sternboard were joined via a curved surface,
Even if the rear end of the second stepper tries to submerge in the water when the bow is lifted, it is formed into a curved surface, so it does not catch on the water surface, so it smoothly enters the water. can do. As a result, the jump can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a bottom perspective view of a hull showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a longitudinal sectional view of the stern stern bottom at a position where a drain plug is attached.

FIG. 5 is an exploded perspective view showing one example of a sponson.

FIG. 6 is a cross-sectional view of FIG.

FIG. 7 is an exploded perspective view showing another example of Sponson.

8 is a cross-sectional view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hull 2 Seat seat 4 Water jet propulsion machine 5 Engine 11 Bottom plate 21 Rear seat seat 44 Stern casing (pump room) 61 1st stepper 62 2nd stepper

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B63B 1/18 B63B 1/32 B63B 35/73 B63H 11/00

Claims (5)

(57) [Claims] In the ship's bottom structure 1. A stern ship bottom jet propulsion devices installed in the watercraft, opening into the vessel bottom
A first stepper is formed on the stern bottom behind the water inlet for the jet propulsion device, the first stepper being formed of a surface located above the front bottom of the stern. The second surface is located above
A bottom structure of a water jet propulsion boat, wherein a stepper is formed. 2. The size of a step between the first stepper and the bottom on the front side thereof is set smaller than the size of a step between the first stepper and the second stepper. 2. The bottom structure of the water jet propulsion boat according to 1. 3. The bottom structure of a water jet propulsion boat according to claim 2, wherein a drain plug is provided on a front wall of the second stepper between the first stepper and the second stepper. 4. The bottom structure of a water jet propulsion boat according to claim 1, wherein the width of the second stepper is set smaller than the width of the first stepper. 5. A second stepper front wall between the first stepper and the second stepper and the first stepper are joined at substantially right angles, and the second stepper and the stern plate are joined via a curved surface. The bottom structure of a water jet propulsion boat according to claim 2, wherein: