JP3176567B2 - Water jet propulsion device and ship equipped with the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a water jet propulsion device for obtaining thrust by pressurizing water taken from an intake port formed in a ship bottom with an impeller of a pump section and jetting the water from a nozzle. And a ship equipped with such a propulsion device.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view of a high-speed ship 101 employing a water jet propulsion device. This figure shows a state where the high-speed ship 101 is stopped on the water surface. FIG.
FIG. 2 is a rear view of the high-speed boat 101 as viewed from a transom 104 side.

The water jet propulsion device 130 is provided at the rear of the hull of the high-speed ship 101. Then, water is taken in from an intake 103 formed as an opening in the bottom 102 of the ship, and this water is supplied to the water jet propulsion device 130.
And pressurized by the pump unit 115 to eject from the nozzle 105. The high-speed ship 101 is propelled by the reaction associated with the backward jet of water flow.

[0004] In the water jet propulsion device 130 as described above, the pump section 115 provided with the impeller 110 is substantially integrated with the rear nozzle 105, and the impeller 11 is provided.
0 and the nozzle 105 are provided coaxially. Water is pressurized by the rotation of the impeller 110. When the high-speed ship 101 is stopped, that is, when the impeller 110 is stopped, substantially the lower half of the impeller 110 is submerged. That is, the center axis of the impeller 110 substantially coincides with the draft line L. The reason why the impeller 110 is arranged in this way is that the pump unit 1 must be submerged to some extent even when the high-speed ship 101 is stopped.
This is because the amount of water sucked from the water intake 103 at the start of the pump 15 is insufficient, the pump 115 cannot be filled with water, and a sufficient propulsive force cannot be obtained.

[0005]

FIG. 8 is a sectional view of the high-speed boat 101 when traveling at high speed. High-speed ship 10
Immediately after 1, the water surface S reaches the lower end of the transom 104.
Is falling. And the water surface S is behind the water line L
The wave rises beyond the peak. The hatched portion in the figure indicates this wave. The larger the waves are formed, the higher the wave making resistance of the high-speed ship 101 becomes.
Propulsion performance is reduced. In order to reduce the wave-making resistance as much as possible, the lower end of the transom 104 is located as shallow as possible below the water line L, or the lower end of the transom 104 is located above the water line L so that high speed What is necessary is just to prevent a wave from being formed behind the ship 101 as much as possible. However, in a ship equipped with a water jet propulsion device, it is necessary to submerge the impeller to some extent at the time of stoppage as described above.
The lower end of the transom will be located at some depth below the waterline. The position of the lower end of the transom is almost determined by the size of the pump, so that it is difficult to reduce the wave-making resistance, and the propulsion performance cannot be improved.

[0006]

In order to solve the above-mentioned problems, the invention of this application has a structure in which a pump portion having an impeller provided therein and a nozzle are separated, and the nozzle is located at a position higher than the pump portion. Have been placed. And this pump part and a nozzle are connected by the waterway. The lower end of the transom where the nozzle is provided, the state in which the ship is stopped
In the vicinity of or above the waterline of the ship. According to this, the lower end of the transom can be positioned higher while the impeller in the pump section is kept submerged even when the pump section is stopped, so that the transom is not submerged. Therefore, the wave making resistance can be reduced and the propulsion performance can be improved.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A water jet propulsion device according to the present invention includes a nozzle provided on a transom of a ship and a pump portion provided with an impeller inside the water jet propulsion device. In a water jet propulsion device that pressurizes water guided to the pump unit by rotation of the impeller and injects the pressurized water from the nozzle to obtain thrust, the pump unit and the nozzle are separated, The nozzle is arranged at a position higher than the impeller,
The pump section and the nozzle are communicated by a water channel, and the vessel
Is stopped, the lower end of the transom is located near or above the waterline of the vessel.

Accordingly, the impeller in the pump section is kept submerged even when the pump section is stopped, while the nozzle is arranged above the impeller. Since the nozzle is arranged at a higher position in this way, when this water jet propulsion device is applied as a propulsion device for a ship, the transom is placed at a position where the lower end is higher than that of a ship to which a conventional water jet propulsion device is applied. Can be formed so that the transom will not submerge
I can do it. In this case, even if the ship is propelled at high speed, no large waves are formed rearward, so that wave making resistance can be reduced and the propulsion performance can be improved.

In the above-mentioned water jet propulsion device, the water channel may be formed in a substantially S-shaped curve. With this configuration, water can be smoothly guided from the pump section to the nozzle, and pressure loss due to the flow of water in the water channel can be reduced.

Further, in the ship of the present invention, an intake port is formed at the bottom of the ship, a nozzle is provided on the transom, water is guided from the intake port to the pump section, and the water is pressurized by an impeller in the pump section. In a vessel that obtains thrust by injecting pressurized water from the nozzle, the pump section and the nozzle are separated, the nozzle is disposed at a position higher than the impeller, and the pump section and the nozzle are connected to a water channel. Communication
In the stopped state, the lower end of the transom is located near the water line or above the water line.

Accordingly, the impeller in the pump section is kept submerged even when the pump section is stopped, while the nozzle is arranged above the impeller. In this way, the nozzle can be located at a higher position .
The transom is not submerged with the lower end positioned higher
I can do it. In this case, even if the ship is propelled at a high speed, no large wave is formed rearward, and the wave making resistance can be reduced to improve the propulsion performance.

In the above-mentioned ship, the water channel may be formed in a substantially S-shaped curve. With this configuration, water can be smoothly guided from the pump section to the nozzle, and pressure loss due to the flow of water in the water channel can be reduced.

[0013]

[0014]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of the marine vessel 1, showing a state where the marine vessel 1 has stopped at the water surface. This ship 1 is a single-hull high-speed ship. FIG. 2 is a rear view of the boat 1 in the state of FIG. 1 as viewed from the rear. L in the figure indicates a draft line.

Referring to FIG. 1, a prime mover 20 is installed inside the hull of the marine vessel 1. In addition, the intake 3 is the bottom 2
The transom 4 is provided with a nozzle 5. A water passage 6 is formed in the hull between the water intake 3 and the nozzle 5. This waterway 6
The impeller 10 is disposed therein. The shaft 11 of the impeller 10 penetrates the wall of the water channel 6 and is coaxially connected to the shaft 21 of the prime mover 20 by flanges 12a and 12b serving as connecting means.

The portion of the water channel 6 from the impeller 10 to the nozzle 5 is curved in a substantially S-shape, and the center axis C1 of the nozzle 5 is located higher than the center axis C2 of the impeller 10. The center axis C2 of the impeller 10 substantially coincides with the draft line L. Therefore, the substantially lower half of the impeller 10 is submerged even when the boat stops. In addition, a pump portion 15 is formed by the impeller 10 and the periphery of the impeller 10 in the water channel 6. The nozzle 5, the pump unit 15, and the water channel 6 constitute a water jet propulsion device. In the conventional water jet propulsion device, the pump unit and the nozzle are formed substantially integrally, whereas in the water jet propulsion device according to this embodiment, the pump unit 15 and the nozzle 5 are separated.

The lower end B of the transom 4 substantially coincides with the water line L. Therefore, the transom 4 is hardly submerged. As described above, the nozzle 5 is connected to the transom 4
, The nozzle 5 is exposed above the water line L and is not submerged at all.

As described above, when the pump unit 15 stops and the ship 1
When the motor 20 is started from the state where the motor is stopped, the impeller 10 connected to the motor 20 starts rotating. Since the lower half of the impeller 10 is submerged, a sufficient amount of water can be sucked from the water inlet 3, so that the water channel 6 is filled with water. The water taken in from the water inlet 3 is pressurized by the pump unit 15 and sent to the nozzle 5 via the water channel 6. Since the portion of the water channel 6 from the impeller 10 to the nozzle 5 is curved in an S-shape, the water flow in the water channel 6 is smooth, and thus no large pressure loss occurs. Then, the pressurized water is jetted rearward from the nozzle 5, and the marine vessel 1 obtains propulsion by the reaction of the jet water flow. The boat 1 is accelerated by this propulsion and gradually becomes faster.

FIG. 3 is a sectional view of the boat 1 traveling at high speed. As described above, even when the vehicle travels at a high speed, the water surface S immediately after the ship 1 substantially coincides with the water line L, and no large wave is formed.
This is because the lower end B of the transom 4 substantially matches the draft line L. Since no large waves are formed, the wave making resistance is small, and the propulsion performance of the boat 1 is improved.

FIG. 4 is a diagram comparing the ship employing the conventional water jet propulsion device and the ship according to the present embodiment by trial calculation of the surplus resistance. In this figure, the horizontal axis represents the Froude number (Fn), and the vertical axis represents the residual resistance. A curve a indicates the characteristics of the ship according to the present embodiment, and a curve b indicates the characteristics of the ship employing the conventional water jet propulsion device. From this figure, it can be seen that the surplus resistance of the ship according to the present embodiment is significantly reduced as compared with the ship employing the conventional water jet propulsion device. This is because the ship of this embodiment
This is due to the fact that waves are unlikely to be formed rearward during traveling and the wave resistance is small.

FIG. 5 shows a ship employing a conventional water jet propulsion device and a ship according to this embodiment.
It shows the result of trial calculation of the relationship between the main engine horsepower (BHP) and the ship speed (Knot). A curve a shows the characteristics of the ship according to the present embodiment, and a curve b shows the characteristics of the ship employing the conventional water jet propulsion device. From this figure, it can be seen that the ship according to the present embodiment can run at a higher speed if the main engine horsepower is the same size, and that the ship according to the present embodiment is smaller than the main engine to run at the same speed. It turns out that horsepower is enough. That is,
The boat according to the present embodiment has improved propulsion performance as compared with a boat employing a conventional water jet propulsion device.

In the above-described embodiment, the structure in which the lower end B of the transom 4 substantially coincides with the water line L is shown. However, the present invention is not limited to this, and the lower end B of the transom 4 may be located above the water line L. Even in this case, since the transom 4 does not submerge, a wave is not easily formed behind the ship, and there is an effect of reducing wave making resistance. Further, the transom 4 does not necessarily need to be formed so as not to be submerged, and the lower end B of the transom 4 may be located below the waterline L. Even with such a configuration, the present invention places the nozzle 5 above the pump section 15, so that the lower end of the transom is positioned higher than the conventional boat in which the impeller and the nozzle are coaxial. Can be located. Therefore, the wave making resistance can be made smaller than that of a conventional ship.

In the above embodiment, the impeller 10 is arranged at such a height that only the lower half is submerged when the boat 1 is stopped. However, the placement height of the impeller is not limited to this position, and if the sufficient amount of water can be sucked in from the water inlet at the time of starting, the submersion may be further shallow,
It may be deeper.

Further, the impeller may be arranged so that the impeller is submerged more than in the embodiment of FIG. For example, the impeller may be arranged at a height such that the entire impeller is submerged.

In the embodiment shown in FIG. 1, a single-hull type high-speed ship is shown as the ship 1, but the present invention is also applicable to a catamaran or a multihull.

[0027]

The present invention is embodied in the form described above and has the following effects.

In the water jet propulsion device according to the present invention, the impeller in the pump section may be arranged so as to be kept submerged even when the pump section is stopped, while the nozzle is arranged above the impeller. So you can
The transom can be formed such that its lower end is located higher. When the transom is formed in this manner, the transom does not submerge, and even when the ship is propelled at a high speed, a large wave is not formed at the rear, so that the wave making resistance can be reduced and the propulsion performance can be improved.

In the above water jet propulsion device, when the water channel is formed in a substantially S-shaped curve, water can be smoothly guided from the pump section to the nozzle, and pressure loss due to the flow of water in the water channel is reduced. Can be smaller.

Further, in the ship of the present invention, the impeller in the pump section can be arranged so as to be kept submerged even when the pump section is stopped, while the nozzle can be arranged above the impeller. Thus, the transom can be formed such that its lower end is located higher. When the transom is formed in this way, the transa
Even when the ship is propelled at high speed, no large waves are formed behind it, and the wave-making resistance can be reduced to improve the propulsion performance.

In the above-mentioned ship, when the water channel is formed to be substantially S-shaped, water can be smoothly guided from the pump section to the nozzle, and the pressure loss due to the flow of water in the water channel can be reduced. .

[0032]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a ship, showing a state where the ship has stopped at the water surface.

FIG. 2 is a rear view of the boat in the state of FIG. 1 as viewed from the rear.

FIG. 3 is a sectional view of a ship traveling at high speed.

FIG. 4 is a characteristic diagram in which a surplus resistance of a ship employing a conventional water jet propulsion device and a ship according to the present embodiment are estimated and compared.

FIG. 5 shows the main engine horsepower (B) of a ship employing a conventional water jet propulsion device and a ship according to the present embodiment.
FIG. 9 is a characteristic diagram showing a result of a trial calculation of a relationship between HP) and a boat speed (Knot).

FIG. 6 is a sectional view of a high-speed ship employing a water jet propulsion device.

FIG. 7 is a rear view of the high-speed ship of FIG. 6 as viewed from a transom side.

8 is a sectional view of the high-speed ship of FIG. 6 when traveling at high speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ship 2 ... Ship bottom 3 ... Water intake 4 ... Transom 5 ... Nozzle 6 ... Waterway 10 ... Impeller 11 ... Shaft 12a, 12b ... Flange 15 ... Pump part 20 ... Motor 21 ... Shaft B ... Lower end of transom C1 ... Center of nozzle Axis C2: Central axis of impeller L: Waterline S: Water surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B63H 11/113 B63H 11/08

Claims (4)

(57) [Claims] A pump provided with a nozzle provided on a transom of the ship and an impeller provided therein, wherein water guided to the pump from a water intake formed on a bottom of the ship is provided to the impeller. In a water jet propulsion device which pressurizes by rotation and injects the pressurized water from the nozzle to obtain thrust, the pump unit and the nozzle are separated, and the nozzle is disposed at a position higher than the impeller. The pump section and the nozzle are communicated by a water channel, and the vessel is stopped.
Water jet propulsion apparatus the lower end of the transom is located above the or waterline waterline vicinity of the ship Te. 2. The water jet propulsion device according to claim 1, wherein said water channel is formed in a substantially S-shaped curve. 3. An intake port is formed in the bottom of the ship, a nozzle is provided in the transom, water is guided from the intake port to a pump section, the water is pressurized by an impeller in the pump section, and the pressurized water is supplied to the nozzle. The pump section and the nozzle are separated from each other, the nozzle is disposed at a position higher than the impeller, and the pump section and the nozzle are communicated by a water channel and stopped. The boat wherein the lower end of the transom is located near or above the waterline. 4. The ship according to claim 3, wherein the water channel is formed in a substantially S-shape.