JPH05319383A - Water jet propeller - Google Patents

Abstract

PURPOSE:To maintain the reliability of equipment by restraining the splash of a jet water flow to the forward side of a deflector at the time of going astern. CONSTITUTION:In a water jet propeller where water is introduced to a pump casing 23 via a sea chest 22 open to a ship's bottom 21, pressurized with an impeller 25 in the casing 23, and jetted from a nozzle 25 at the ship's stern for providing thrust, this water jet propeller is equipped with a steering duct 30 so provided as to communicate with the nozzle 27 and to be capable of turning port and starboard, a deflector 31 for selectively covering the aft end opening of the duct 30, and a seal member 35 laid on the fore end internal wall of the deflector 31 and having expansion and contraction capability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet propulsion machine provided in a high speed boat or the like, and more particularly to a water jet propulsion machine having an improved reverse mechanism.

[0002]

2. Description of the Related Art Generally, a water jet propulsion machine is shown in FIG.
As shown in FIG. 2, a water guide duct 4 that guides water taken in from an intake port 2 opened to the bottom 1 into a pump casing 3, a pump impeller 5 that rotates inside the pump casing 3,
It has a diffuser 6 provided on the outlet side of the pump impeller 5 and a nozzle 7 for injecting a water flow.

Further, the water jet propulsion machine is usually provided with a steering mechanism for changing the direction of the watercraft and a reverse mechanism for braking from the forward direction or for the reverse direction. FIG. 9 shows an example of a conventional water jet propulsion machine equipped with both a steering mechanism and a reverse mechanism. In this water jet propulsion machine, the steering duct 9 is provided at the rear end of the nozzle 7 via mounting means such as a pin 8 ( The steering duct 9 is provided with a pin 1 so as to be rotatable (pivoting) in the horizontal direction.
A deflector 11 is provided rotatably in the vertical direction via a mounting means such as 0, and a reversing duct 12 for reverse is provided below the steering duct 9.

Steering is performed by turning the steering duct 9 to the left or right, and the jetted water flow to the rear of the steering duct 9 is closed by the deflector 11, and water is jetted forward from the reversing duct 12 to brake or move forward. The reverse is performed.

[0005]

However, in the above-mentioned conventional water jet propulsion machine, as shown in FIGS.
When the watercraft moves from forward to brake or reverse as shown in Fig. 1, the deflector 11 is pushed downward from the forward position, and then the rear end opening of the steering duct 9 is closed, so that the nozzle 7 is moved backward. The jet water flow to be jetted has its flow direction changed by the deflector 11 and the reversing duct 12, and is jetted from the outlet of the reversing duct 12 to the lower side of the steering duct 9.

In this case, when the deflector 11 is pushed down to start closing the rear end opening of the steering duct 9, the jet water flow collides with the inner wall of the deflector 11 and the flow is reversed, so that the jet water flow below the steering duct 9 falls. The degree of inflow into the reversing duct 12 from the opening increases, and a part of the water flow is transmitted to the front of the deflector 11 through the inner wall of the deflector 11 through the gap between the inner wall of the deflector 11 and the outer wall of the rear end of the steering duct 9. ..

Therefore, a part of the water stream is deflected by the deflector 1.
1 If the water flow is seawater, the damage to the steering device and other equipment in front of the deflector 11 will be great due to rusting and the like, and the function of the equipment will decline and the service life will be shortened. However, there is a problem in that

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a water jet propulsion device which suppresses the scattering of a jet water flow to the front of the deflector at the time of reverse travel and maintains the reliability of the device. And

[0009]

In order to solve the above-mentioned problems, a water jet propulsion machine according to the present invention introduces water into a pump casing from a water intake opening at the bottom of a ship,
In a water jet propulsion machine in which water is pressurized by an impeller inside the pump casing and jetted from a nozzle provided at the stern to obtain thrust, a steering duct that is connected to the nozzle and is rotatable left and right, The deflector selectively covers the rear end opening of the steering duct, and a seal member provided on the inner peripheral wall of the front edge of the deflector and having a stretchable function.

[0010]

In the present invention having the above-mentioned structure, since the seal member is provided on the inner peripheral wall of the front edge of the deflector, a gap between the inner wall of the deflector and the outer wall of the rear end of the steering duct is generated during the closing operation of the deflector. A part of the jet water flow which is transmitted from the inner wall of the deflector to the front of the deflector is blocked and suppressed by the seal member.

After that, when the rear end opening of the steering duct is closed, the seal member is pressed against the outer wall of the steering duct by the internal pressure. As a result, the gap between the inner wall of the deflector and the outer end wall of the rear end of the steering duct is completely closed, and the water flow is entirely jetted to the lower side of the steering duct to reliably prevent the scattering to the front of the deflector.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a water jet propulsion machine according to the present invention will be described below with reference to FIGS.

In the water jet propulsion machine of this embodiment, as shown in FIG. 4, a water guiding duct 24 for guiding water taken in through a water intake 22 opened in a ship bottom 21 into a pump casing 23.
A pump impeller 25 rotating inside the pump casing 23, a diffuser 26 provided on the outlet side of the pump impeller 25, and a nozzle 27 for injecting a water flow.

Further, at the rear end of the nozzle 27, as shown in FIG. 1, left and right (horizontal) via mounting means such as a pin 29.
A steering duct 30 rotatable in the direction is provided, and the steering duct 30 is driven by the steering actuator 28. A deflector arm 32 that is vertically rotatable is provided at the rear of the steering duct 30 via a mounting means such as a pin 33, and the deflector arm 32 is driven by a reverse drive actuator 34. A deflector 31 is attached to the deflector arm 32 to selectively cover the rear end opening of the steering duct 30.

On the inner peripheral wall of the front edge of the deflector 31,
As shown in FIG. 3, a sealing member 35 made of, for example, a rubber-based elastic material and having an expanding / contracting function is attached. When the deflector 31 closes the rear end opening of the steering duct 30, the steering duct is caused by internal pressure. It is pressed against the outer wall of 30. Further, an inversion duct 36 is provided below the rear portion of the steering duct 30. Next, the operation of this embodiment will be described.

When the course is changed when the vehicle moves forward, the steering actuator 28 is operated by a command from a steering control device (not shown) in this embodiment. Then, the steering duct 30, which is provided at the rear end portion of the nozzle 27 so as to rotate in the horizontal direction via the attachment means such as the pin 29, becomes the pin 2.
Move 9 left or right around 9 as the center of rotation,
The jet water flow jetted backward from the nozzle 27 is deflected to obtain a force that changes the course direction of the boat, and the boat is steered.

At the time of steering during such forward movement, as shown in FIG. 5, a pin 33 is provided at the rear portion of the steering duct 30.
Since the deflector arm 32, which is provided so as to rotate in the vertical direction via the attachment means such as, does not operate,
The rear end opening of the steering duct 30 remains open, and the jet water flow jets out into the air behind the steering duct 30. Next, the operation during forward braking or the operation during reverse traveling will be described.

When the vehicle moves from forward to braking or to reverse operation during navigation, the reverse actuator 34 is actuated as shown in FIG. 6 (A) by a command from a reverse controller (not shown), which causes the deflector to move. The arm 32 is pushed downward from the forward position, and the deflector 31 attached to the deflector arm 32 starts to close the rear end opening of the steering duct 30.

During the operation of the deflector 31, as shown in FIG. 6B, the inner wall of the deflector 31 is transmitted from the gap between the inner wall of the deflector 31 and the rear end outer wall of the steering duct 30 to the front of the deflector 31. A part of the jet water flow that is about to be scattered is blocked and suppressed by the seal member 35.

After that, when the rear end opening of the steering duct 30 is closed by the deflector 31 as shown in FIG. 7A, a pressure higher than the atmospheric pressure acts on the inside of the seal member 35. As shown in FIG.
Is pressed against the outer wall of the steering duct 30 by its internal pressure. As a result, the gap between the inner wall of the deflector 31 and the outer wall of the rear end of the steering duct 30 is completely closed, and the water flow is entirely injected from the outlet of the reversing duct 36 to the lower side of the steering duct 30, and the jet water flow to the front of the deflector 31. Is reliably prevented.

[0021]

As described above, according to the water jet propulsion apparatus of the present invention, the seal member is provided on the inner peripheral wall of the front edge of the deflector, so that the deflector scatters forward while the deflector is closing. A part of the jet water flow to be attempted is blocked and suppressed by the seal member,
When the rear end opening of the steering duct is closed, the seal member is pressed against the outer wall of the steering duct by the internal pressure, the gap between the inner wall of the deflector and the rear end outer wall of the steering duct is completely closed, and the jet forward It is possible to reliably prevent the water flow from scattering.

As a result, even if the water flow is, for example, seawater, damage to the equipment such as the steering device in front of the deflector is reduced, the life is extended, and the reliability of the equipment can be maintained.

[Brief description of drawings]

FIG. 1 is a side view of essential parts showing an embodiment of a water jet propulsion device according to the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is an enlarged view of part B in FIG.

4 is a vertical cross-sectional view showing the overall configuration of the water jet propulsion device in FIG.

FIG. 5 is a side view showing a state when the steering duct in FIG. 1 is moving forward.

6A is a side view showing a state in which the deflector of FIG. 1 is in the middle of operation, and FIG. 6B is an enlarged view of a C portion in FIG. 6A.

7A is a side view showing a state in which the deflector of FIG. 1 is closed, and FIG. 7B is an enlarged view of a portion D in FIG. 7A.

FIG. 8 is a vertical cross-sectional view showing a conventional water jet propulsion machine.

9 is a side view showing a steering duct of the water jet propulsion machine of FIG. 8. FIG.

10 is a side view showing a state in which the deflector in FIG. 9 is in the middle of operation.

11 is a plan view of FIG.

[Explanation of symbols]

 21 Ship Bottom 22 Water Intake 23 Pump Casing 24 Water Transfer Duct 25 Pump Impeller 26 Diffuser 27 Nozzle 28 Steering Actuator 30 Steering Duct 31 Deflector 32 Deflector Arm 34 Reverse Actuator 35 Sealing Member 36 Inversion Duct

Claims (1)

[Claims] 1. A water jet propulsion machine in which water is introduced into a pump casing from a water intake opening at the bottom of the ship, the impeller in the pump casing pressurizes the water, and the water is ejected from a nozzle provided at the stern to obtain thrust. A steering duct that is connected to the nozzle and is rotatable left and right, a deflector that selectively covers a rear end opening of the steering duct, and a seal that is provided on an inner peripheral wall of a front edge of the deflector and has an expanding and contracting function. A water jet propulsion machine comprising a member.