JP2584447Y2 - End-open type inflatable boat - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end-open type inflatable boat on which an outboard motor or an inboard motor can be mounted, and more particularly to the inflatable boat capable of exhibiting a stable turning (turning) characteristic.

[0002]

2. Description of the Related Art In recent years, inflatable boats have been constructed using a highly rigid, highly durable and safe cylinder. Along with this, the boat is equipped with a high horsepower engine and is used for various purposes such as high-speed cruising and water ski traction, and requires a running performance equal to or higher than that of an FRP boat or an aluminum boat. It has become. In such an inflatable boat, as shown in FIG. 5, a ship bottom 11 is generally composed of a synthetic rubber cloth and a wooden plate bottom, and the periphery of the ship bottom 11 is made of a special synthetic rubber based on heavy duty nylon or the like. A U-shaped cylinder 12 is mounted open at the rear of the body.

[0003] At the time of stop, the U-shaped ends of the cylinder 12 prevent the sinking of the stern due to the weight of the outboard motor to balance the body, and to prevent excessive movement of the body before entering the run. In order to obtain the buoyancy necessary to prevent standing up, the tail portion 1 projects rearward from the transom board 14 (a back plate on which the outboard motor is mounted) and has a generally conical tip.
3 is formed.

However, in the conventional end-open type of the above-mentioned body, if the tail part is lengthened in order to obtain a sufficient buoyancy behind the body, the tail part receives greater resistance from water when turning, Since the propulsive force is reduced, a good turning torque cannot be obtained, and the turning characteristics are inferior to those of an FRP boat or an aluminum boat. On the other hand, if the length of the tail part is shortened to reduce the resistance that the tail part receives from the water at the time of turning, sufficient buoyancy behind the body will not be obtained,
At the time of stoppage, there are problems such as sinking of the stern due to the weight of the outboard motor and excessive rise before entering the gliding state. I couldn't.

The present invention has been proposed in order to solve the above-mentioned problems, and is an end-opening which is excellent in turning property and can prevent sinking of the stern due to good buoyancy behind the body. It is an object of the present invention to provide a type of inflatable boat.

[0006]

Means for Solving the Problems As a result of repeated studies to achieve the above object, the inventor of the present invention has found that the turning characteristics of an inflatable boat are greatly affected by the length and shape of a tail portion. The turning characteristic is inferior because the propulsion force is not efficiently converted to turning torque because the tails projecting in parallel to obtain sufficient buoyancy behind the hull increase resistance during turning. I got the conclusion. Based on the conclusion, it was found that if the tail portion is formed into a shape that reduces resistance during turning without impairing the buoyancy of the stern, a boat with excellent turning characteristics and a well-balanced body can be realized. This led to the present invention.

That is, in the end-open type inflatable boat of the present invention, both rear ends of a substantially U-shaped cylinder mounted around the bottom of the boat are bent inward.
Ri, bent portions of both the rear end of the front Kikido is substantially a truncated cone or conical, the center axis of kidou non bent portion, the bent portion
So that the center axis of the
The bent portion is formed such that the angle between the oblique side of the outermost end of the body of the bent portion and the center axis of the body is in the range of 30 to 60 degrees.

[0008] If the tip of the tail portion of the cylinder of the inflatable boat of the present invention is formed by bending inward of the body, good turning characteristics can be obtained as described later, but not so much. If the bend angle is too large, the resistance of water will be rather large during straight running, and if it is too small, the effect of improving turning performance will be reduced. For this reason, depending on various conditions such as the size of the body, the type of engine (whether outboard or inboard) or horsepower, the outermost diagonal line of the truncated cone or conical bent portion is usually angle between Teitai central axis (i.e., generally the angle between the central axis of the non-bent portion of the tail section) shall be the 30 to 60 degrees.

Whether the shape of the bent portion is a truncated cone or a conical shape, and how much the bent angle, length, volume, etc. of the bent portion are to be determined by computer simulation, It is determined as appropriate by a running test using a prototype. The bent portion may be provided such that the central axis thereof is horizontal (that is, the central axis of the non-bent portion of the tail portion and the central axis of the bent portion are on the same plane), The shaft may be provided so as to have an angle of, for example, several degrees to tens of degrees above (that is, to jump at the angle).

Further, the inflatable boat of the present invention can be used by attaching an outboard motor, or can be used by mounting an inboard motor (a screw rotating mechanism, a water jet driving mechanism, etc.). If the non-bend portion of the tail portion is too long, the resistance of water at the time of turning increases, and good turning characteristics cannot be obtained. Therefore, it is preferable that the non-bend portion is as short as possible or has no portion.

[0011]

The conventional inflatable boat with a straight tail has a large resistance from the water surface when turning, so the propulsion is reduced by friction with the water and the like, and excessive pulling and splashing occur. In the inflatable boat, since the tail is bent inward, the above-mentioned friction and the like received at the time of turning are drastically reduced, and not only high-efficiency turning torque is generated, but also the occurrence of excessive rips and splashes is suppressed. You. At the same time, in the inflatable boat of the present invention, the tail part provides sufficient buoyancy to the rear part of the body, so that even when the outboard motor or the inboard motor is mounted and stopped, the balance of the body is well maintained, Excessive rise (bow-up) of the body even at low speeds such as at the start of running, because the tail part contacts the water surface and gives buoyancy.
Is prevented.

FIG. 1 shows one cause of the above-mentioned drastic reduction of friction.
Description will be made with reference to (A) and (B). When the body changes direction, the body performs a rotation operation (shown by a rotation direction RD in FIGS. 1A and 1B) around the center of the boat. Like a traditional inflatable boat,
Both tails (T) project rearward in parallel (see FIG. (A)), and when the tails (T) are bent inward as in the boat of the present invention (FIG. (B)). With reference to the above, when the body rotates around the center of the boat (indicated by C), the resistance that the tail (T) receives from the water (in other words, the tail (T) will push the water away) Force) is overwhelmingly greater in the former case. actually,
The body does not necessarily rotate around the center of the boat in a fixed position, but generally follows the mechanism described above.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a partial perspective view of the rear part of the inflatable boat of the present invention. In addition, in the figure, the illustration of the ship bottom is omitted. The boat shown in the figure is used by attaching an outboard motor to the transom board 14, as in the case shown in FIG. A portion (tail portion 3) behind the transom board 14 of the U-shaped cylinder 2 is connected to a non-bent portion 3a having a center axis L1 substantially parallel to the center axis L0 of the body, and to the non-bent portion 3a. And a bent portion 3b bent inside the body 1.

In FIG. 1, the bent portion 3a has a substantially frusto-conical shape, but may have a substantially conical shape (ie, a shape with a sharp tip). When the bent portion is formed into a truncated cone shape, both bottom surfaces of the truncated cone (the plane formed by the elliptical ridge formed by the non-bent portion 3a and the bent portion 3b and the tip surface of the bent portion 3b) are not necessarily parallel. No need to be. In FIG. 2, the distal end face of the bent portion 3b is set at an angle so as to reduce the resistance due to water. It is needless to say that the tip of the bent portion 3b does not need to be flat, and may be formed in a hemispherical shape.

On the other hand, if the degree of bending of the bent portion 3b is excessively large, the steering performance is impaired, for example, the water resistance increases during straight running, and it becomes impossible to obtain a suitable body balance during turning or the like. If it is too small, the effect of reducing the resistance generated at the time of turning intended by the present invention cannot be exhibited effectively. For this reason , the bent portion 3b is formed by an angle formed by the outermost end hypotenuse Lα and the center axis L0 of the body (in FIG.
a is an angle formed with the outermost end line Lβ of a).
Bend so that it becomes 0 degrees.

The tail portion 3 in FIG. 1 is configured such that the center axes L1 and L1 of the non-bent portion 3a and the center axes L2 and L2 of the bent portion 3b are on the same plane.
As shown in the figure, the central axes L2 and L2 are different from the central axes L1 and L1.
May be provided so as to be inclined at a constant angle δ (usually several degrees) with respect to a plane including Note that L 'in FIG.
This is an auxiliary line for illustrating the above δ, and is on a plane including L1 and L1. The intersection of L1 and L2 is n, L2 and L
2 is o, and the point at which a perpendicular passing through o intersects the plane (plane including L1 and L1) is m, mn is a straight line L ', and the angle formed by L' and L2 is δ Generate

FIGS. 4A and 4B are a partial top view and a partial side view of a stern showing a more specific embodiment of the inflatable boat of the present invention. The inflatable boat shown in the figure is of a type (total length of about 4.0 m) on which a water jet propulsion device is mounted, and has a width W of about 1.7 m and a diameter D of about 420 mm. The shape of the bent portion 3b is substantially a truncated cone like the shape shown in FIGS. 2 and 3, and the center axis L1 of the non-bent portion 3a and the center axis L2 of the bent portion 3b are The distance Q to the intersection of is approximately 15
It is about 0 mm. Note that the distance Q varies depending on the size of the body, the weight of the outboard motor, and the like, but can be approximately 0 to 350 mm.

The ridge V of the bent portion formed at the boundary between the non-bent portion 3a and the bent portion 3b has an elliptical shape having a minor axis radius equal to the diameter D of the cylinder. With a truncated cone having a bottom surface equal to this elliptical shape (a truncated cone formed by diagonally cutting two places of a cone at different predetermined angles),
A bent portion 3b is formed. In the figure, the angle between the hypotenuse of the outermost end of the body and the center axis of the body (in the figure, the angle formed with the outermost end line p of the non-bent portion 3a for convenience) θ is 4
The angle between the hypotenuse of the innermost end of the body and the center axis of the boat (also indicated by the angle formed with the innermost end line q of the non-bent portion 3a) θ 'is approximately 23 degrees. Have been. In the above embodiment, the axis L is the same as in the case of FIG.
1 and L2 are configured to be on the same plane.

[0019]

According to the present invention, since both ends (tails) of the U-shaped cylinder are bent toward the inside of the body, good turning characteristics (that is, good steering characteristics) can be obtained. That is, unlike a conventional boat, an excessive underwater is generated at the time of medium / high speed turning, and the propulsion energy is not reduced by water resistance, so that it is possible to continue well-balanced and comfortable cruising, In addition, fuel economy has been improved compared to the past. In addition, even when the vehicle is stopped or running at low speed, the tail of the cylinder can provide good buoyancy to the rear part of the body, so that a well-balanced inflatable boat can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining an operation of the present invention;
(A) is a diagram showing a state of a conventional end-open type inflatable boat when turning, and (B) is a diagram showing a state of the inflatable boat of the present invention when turning.

FIG. 2 is an explanatory view showing a stern portion of one embodiment of the present invention.

FIG. 3 is an explanatory view showing a stern portion of another embodiment of the present invention.

FIG. 4 is a diagram showing a more specific embodiment of the present invention;
(A) is a plan view showing a stern portion, and (B) is a side view of the same.

FIG. 5 is a view showing a conventional inflatable boat.

[Description of Signs] 1 Body 2 Cylinder 3 Tail 3a Non-bent part of tail 3b Bent of tail 14 Transom board L0 Center axis of body L1 Center axis of unbent part L2 Center axis of bent part C Center of the body

Claims (1)

(57) [Scope of request for utility model registration] 1. A are both the rear end of the air cylinder of the generally U-shaped which is attached to the ship's bottom periphery, a end open type inflatable boat formed by bent inward, both the trailing edge of the preceding Kikido The bent part of the part is roughly frusto-conical or conical, with the central axis of the cylinder in the non-bent part and the
It is configured so that the center axis of the torso is approximately coplanar.
Is, as the angle between the hypotenuse and Teitai central axis of the Ting body outermost end of the bent portion is in the range of 30 to 60 degrees, the end open type, characterized in that the curved fold portion is formed
Inflatable boat .