JPS62122896A - Small jet propulsion boat - Google Patents

Abstract

PURPOSE:To make high speed-straight driving capability good by double chines formed in the ship bottom, and to make high speed-shuttle turn possible by an outside chine formed in the front and a flat bottom formed in the rear. CONSTITUTION:A bottom plate 20 is formed by a keel 22 in the center of the width and inclined faces on the both sides. Double chines 28, 29 are formed in the bottom plate 20. The outside chine 28 is formed by an almost vertical side plate 80 and an almost horizontal bottom plate 89. Both chines 28, 29 are curved so that their both sides are parallel each other in the rear from the center in a lengthy direction and approach the ship center line in the front from the center. The keel 22 is gradually narrowed in the front from the center in a lengthy direction, and also the angle of inclination of inclined faces on both sides is gradually increased.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to small-sized propulsion boats that are mainly for one or two people and sail at high speed on the sea, and which have particularly excellent straight-line high-speed cruising and sudden rapid cruising. It is related to something that makes it possible to turn around.

(Prior art) In general, the longer the side length of a ship, the more straight-line it will be.
Improving straight-line performance reduces turning performance.

However, the specifications of these ships are determined at the time of design and do not change afterwards, making it difficult to achieve both straight-line performance and turning performance.

(Objective of the Invention) The object of the present invention is to provide a jet-propelled small personal watercraft that can simultaneously satisfy the contradictory demands of straight-line performance and turning performance of the watercraft.

(Structure of the Invention) The present invention includes a seat formed in the widthwise center part of the boat body on the rear side from the longitudinal center part, and a steering wheel supported by a handle support part fixed to the boat body. An outer chine placed in front of the seat and formed at the joint between the side plate and the bottom plate and an inner chine formed inside the outer chine form an inner and outer chine. Both sides of the hull are parallel to each other on the rear side of the center in the longitudinal direction of the hull, and curved so that the front side of the center is closer to the hull center line, and the bottom of the hull on the rear side of the center of the hull is designed to resist lateral movement. It is formed into a small flat shape.

In the above configuration, by shifting the pilot's weight forward and backward, the double chine allows for good high-speed straight-line performance when the draft at the stern is increased, and when the draft at the front is increased, the outer chillin The flat bottom of the rear part enables high-speed spin turns, and the outer chine allows a large heel angle to be stably obtained when turning.

(Example) In FIGS. 1 to 3, the hull 100 has drainage water in the area surrounded by the bottom plate 20, the side plates 80, the upper deck 21 formed forward of the center of the hull, and the stern plate 70. A substantially sealed engine room is formed in a portion surrounded by the bottom plate 20 and the upper deck 21.

Further, a seat 50 is formed protruding from the center in the width direction of the ship, and a foot deck 30 that opens to the stern end is formed between the seat 50 and the gunwales 88 on both sides. The underside of the foot deck 30 and the seat 50 is also configured to have a drainage volume.

A handle support part 61 is fixedly attached on the upper deck 21, and a handle 60 is formed at the upper end thereof.The part of the deck 21 where the handle support part 61 is provided is formed to protrude, and a buoyancy space is provided in the lower part of the deck 21. An engine room is formed. Further, the operator 11 on the seat 50 is configured to operate the boat 100 by gripping the handle 60 with his feet placed on the foot deck 30.
Also, from this state, the pilot 11 stands up and shifts his weight back and forth.
It allows you to move it left and right.

A propeller (not shown) rotates on the engine in the engine room, sucks water from the water suction port on the bottom of the boat, passes it through a flow path formed under the seat 50, and swings the water in the horizontal direction of the stern. By jetting water backward from the nozzle 71, turning force and propulsive force are generated.

The boat bottom shape is configured as shown in FIGS. 3 and 5 (A) and (B). That is, the bottom plate 20 is composed of a keel 22 at the center in the width direction and inclined surfaces on both sides of the keel 22, and double inner and outer chines 28 and 29 are formed on this bottom plate 20, and the outer chines 28 are connected to a substantially vertical side plate 80. and a substantially horizontal bottom plate 89. Further, the inner chine 29 is formed so as to protrude triangularly from the inclined surface of the ship's bottom in cross section. Both chines 28 and 29 are formed so that both sides thereof are parallel to each other on the rear side from the center part in the longitudinal direction of the hull, and are curved so as to approach the hull centerline on the front side of the center part.

The keel 22 is formed so that its width gradually becomes narrower on the front side from the center in the longitudinal direction of the hull, and the sloped surfaces on both sides thereof are set so that the angle of inclination gradually increases, so that the keel 22 has an overall V-shape. Further, the width of the keel 22 is wider at the rear side of the center portion, and the inclination angle θ of the inclined surfaces on both sides of the keel 22 is set small, resulting in an overall flat shape. The above inclination angle θ is about 15°, and the width of the keel 22 is 1 of the width of the ship.
/4 is set.

In the above configuration, the center of gravity G with the operator 11 riding
o is set rearward from the center in the lengthwise direction of the hull, and the water line area shape 23 when traveling straight becomes 1' as shown by diagonal lines in FIGS. It has an eel shape. In other words, water is drained by the inside gear 29 to reduce the waterline area, and the center of gravity Go is on the rear side, and the flat bottom of the ship occupies a large proportion of the total waterline area, and the bottom of the ship is relatively flat. Because of this, the propulsion resistance is small.

In addition, the distribution of the pressure received from the water on the bottom of the ship when the ship is going straight is as shown by the curve 24 in Figure 4 (A) (B) and Figure 6 (8) (B), in the width direction central part and the inner side 29. The pressure is high, and the pressure at the front of the machine is high.

On the other hand, when making a turn, when the operator 11 stands up, shifts his weight forward and sideways, and steers the boat at a predetermined steep angle, the hull tilts and the outer chine 28 tilts as shown in FIG. The front part of the machine is immersed in water to drain water. At this time, since the front part of the outer chine 28 is curved so as to approach the center line of the hull, a braking effect is achieved by immersion in the water, making it possible to make a sharp turn, and the outer chine 28
Because it is formed at a steep angle (the cross-sectional shape is almost a right angle), it has great resistance to tilting (difficulty in overturning).

Moreover, the pressure distribution becomes as shown by the curve 25A in FIG. 4(A) and FIG. 6(A), and a large pressure is generated in the outer chine 28 and inner chine 29 portions, and
A large amount of pressure is also generated on the opposite side of the ship's bottom slope, which helps keep the slope stable. Further, the waterline area shape 27A in the inclined state is formed to be inclined across one side on the front side and the other side on the rear side, as shown in FIG. 5(A).

In order to tilt the boat, the operator 11 shifts his weight to the side and forward as described above, but as a result, the center of gravity Go becomes G1.
Move to. In addition, the center of pressure in the longitudinal direction is Bo when traveling straight.
, fl￥i In the oblique state, the distance from the center of gravity is QO, but in the inclining state, the distance from the center of gravity is Q1, which is larger than ρ0, and the rear bottom of the ship is formed flat, reducing lateral movement resistance. Because of this small amount, the brakes are applied to the front bottom of the ship, and the rear bottom of the ship skids, causing a sharp turn (spin turn). In order to stably perform such sharp turns, a handle support part 61 that supports the handle 60 is fixedly attached to the hull, and the operator 11 can move around the hull by gripping the handle 60. I am able to maintain this posture.

In addition, in order to make a sharp turn when traveling straight at high speed, if the body of the boat is tilted by shifting its weight to the rear and side, the rear of the outer chine 28 will be immersed in the water as shown in Fig. 4 (B). Moreover, since the outer chine 28 is formed at a steep angle (nearly a right angle), it has great resistance to tilting (resistance to overturning). In addition, the pressure distribution becomes as shown by the curve 25B in FIGS. 4(B) and 6(B), and a large pressure is generated at the outer chine 28 and inner chine 29 parts, and at the same time, on the opposite side of the bottom inclined surface. Also, large pressures are generated, which keep the tilting state stable. Further, the water line area shape 27B in the inclined state is biased toward the inclined side as shown in FIG. 5(B). In this state, a small turn at high speed, a so-called edging turn, is made.

When the weight is shifted to the side and rear in order to tilt the boat, the center of gravity Go moves to G2. In addition, the center of pressure in the longitudinal direction is Bo in the straight-ahead state and B2 in the incline state, and as a result, the distance from the center of gravity position in the straight-ahead state was Qo, but in the incline state the distance is 1IlltQ2, which is smaller than ρ0. Therefore, by moving the body hair to the side, stable high-speed small turns can be made.

(Effects of the Invention) As explained above, this invention enables the operator to shift his/her weight and maintain a stable attitude, and the double chine at the bottom of the boat allows for 8-speed straight-line performance. The outer chines at the front and the flat bottom at the rear make it easy to make sharp turns, making it possible to make high-speed turns (spin turns) and to make so-called edging turns with the outer chines. This made it possible to stably tilt to a large angle of inclination, thereby making it possible to make sharp turns at high speeds.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an actual droplet example of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a rear view thereof, and Figs. 4 (A) and (B) are pressure distributions in the cross-sectional shape of the hull. Figure, Figure 5 (A
) (B) is a bottom view without showing the shape of the waterline area of the hull, Figure 6 (
A) and (B) are views of the pressure valve 45 in the longitudinal direction of the hull. 100... Hull, 11... Operator, 20... Bottom plate, 22... Keel, 23.27A, 27B... Water line area shape line, 24.25A, 25B... Pressure distribution Curve, 28...Outside chi P-in, 29...Inner chine,
30...foot deck, 50...seat, 60...
Handle, 61...handle support part. Patent Applicant Yamaha Motor Co., Ltd. Agent Patent Attorney Etsushi Kosho Patent Attorney Chief 1) 1 Patent Attorney Yasuo Itasho Figure 3

Claims (1)

[Claims] 1. A seat is formed at the center in the width direction behind the center in the length direction of the boat, and a steering handle is supported by a handle support part fixed to the boat and is arranged in front of the seat. , an outer chine formed at the joint between the side plate and the bottom plate and an inner chine formed inside the outer chine form an inner and outer chine, and the rear side of both chines from the center in the longitudinal direction of the hull is Both sides are parallel to each other, the front side of the center part is curved closer to the hull center line, and the bottom of the hull rearward of the center part is formed into a flat shape with little resistance to lateral movement. Small jet propulsion boat.