JP2756431B2 - Reverse gear for marine water jet propulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a water jet thruster of the type in which a turning support point of a flap is provided at an upper part of a steering cylinder and a reverse state is formed while suppressing a jet flow emitted from a jet nozzle. More specifically, the present invention relates to a reverse device, in which the jet flow escaping from both sides of the flap when moving from a forward to a reverse state is minimized to improve reverse performance (maneuverability) and maneuvering responsiveness at the time of the reverse movement, and particularly for berthing and maneuvering. The present invention relates to a reversing device for a marine water jet propulsion machine suitable for a high-speed ship such as a passenger ship with many vehicles.

[0002]

2. Description of the Related Art In recent years, in response to the need for speeding up marine transportation, a jet stream pressurized by a pump of a water jet propulsion device arranged at the stern is 30 to 50 m / m from a jet nozzle.
A water jet propulsion ship that jets out at a flow rate of s and sails using the reaction force as a propulsion force is in the spotlight. By the way, such a water jet propulsion device is provided with a flap that opens and closes a rear opening of a steering cylinder and switches between forward and backward travel. Among those, there are two types in a form of a flap support position and a turning of a jet flow. is there. one,
As shown in FIG. 10, the turning support point 52 of the flap 51 is provided at the upper part of the steering cylinder 53.
1 is operated in an inclined and inclined state to shift from a forward movement to a backward movement while suppressing the jet flow emitted from the ejection nozzle 54. Another one is disclosed in Japanese Unexamined Patent Publication No.
JP-A-78683 discloses a type in which a turning support point of a flap is provided at a lower portion of a steering cylinder, and the flap is operated in an upright inclined state so as to shift from a forward state to a reverse state while sequentially removing a jet stream. belongs to.

[0003] In the latter type, the flap operates inside the steering cylinder, so that even if the jet flow hitting the flap diverges to both sides, it does not hit the side wall of the steering cylinder and escape or leak outside.

[0004]

However, in the former type, when the direction of the jet stream is changed while the jet stream is held down by the flap, the front end of the flap projects outside the steering cylinder and hits the flap. A portion of the subsequent jet stream tends to escape and leak from both sides of the flap. As a result, even when the flap is operated in the reverse direction, the acting force (thrust) does not easily change from the forward direction to the reverse direction. The so-called reverse performance becomes insensitive and the steering cannot be performed as desired (that is, deviates from the feeling of maneuvering), and the maneuvering response is low and the maneuverability is poor. However, once the flap enters the inside of the steering cylinder, the leakage of the jet flow is stopped at the side wall of the steering cylinder, so that the entire flow is bent by the straightening plate and directed in the reverse direction. Although it does not readily decrease and does not change, it suddenly switches from forward to reverse at a certain flap operation angle. This process is shown by a solid line in FIG.

FIG. 9 is a diagram showing how the thrust changes with respect to the operation angle of the flap, with the horizontal axis representing the flap operation angle and the vertical axis representing the forward or backward thrust. In a normal flap, the forward thrust does not decrease so much even if the flap operation angle is increased, and suddenly changes from forward to reverse thrust at a certain operation angle. The reverse thrust appears at a later time, and appears only when the flap operation angle is set close to the full reverse position. When a ship enters the bay and berths or breaks off, the water jet propulsion system must frequently switch back and forth by flaps of the reversing device to make fine adjustments (forward and backward movement or turning). At this time, when the forward / backward switching is abrupt, that is, when the flap changes greatly or reverses only by slightly moving the flap, delicate boat maneuvering becomes difficult. Therefore, it is desirable to reduce the forward thrust and smoothly change the forward thrust in accordance with the flap operation angle so as to match the feeling of maneuvering. Further, from the viewpoint of steering response and reverse performance, it is desirable for the reverse thrust to appear as early as possible.

The invention according to this application is directed to a water jet propulsion device of a type having a rotation fulcrum of a flap at an upper part of a steering cylinder and forming a reverse state while suppressing a jet flow emitted from an ejection nozzle. It is an object of the present invention to provide a marine water jet propulsion reversing device having excellent steering responsiveness at the time of transition to a state and excellent reverse performance and ship maneuverability.

[0007]

Means for Solving the Problems A solution for achieving the above object is to provide a jet nozzle for jetting a jet stream, a steering cylinder that can swing left and right at the rear of the jet nozzle, and an upper part of the steering cylinder. rotatably provided with a flap of which one end is supported on, the flap, the reverse state is formed to close the rear opening of the steering cylinder is inclined fallen state and the steering cylinder is in a state of getting up in a substantially horizontal the rear opening to open ECTS of
Both are premised on a water jet propulsion device of a type in which at least a part thereof is exposed from the steering cylinder to the publication to form a forward movement state.

[0008] As means of claim 1, the both side ends of the inner surface of a jet stream of the flap hits, those on the flap
Only the jet stream splits in both sides and the flaps
If a side fence is provided to prevent escape from the side, the jet flow hitting the flap during transition from the forward to the reverse state (that is, when the flap transitions to the inclined state in which the flap is inclined downward from horizontal) is provided. The side fence blocks the part from escaping or leaking from both ends of the flap. As a result, a smooth decrease in forward thrust commensurate with the flap operation angle (that is, in accordance with the maneuvering sensation) and an increase in the reverse flow speed the reverse thrust onset time, thereby improving reverse responsiveness and reverse performance. . Also,
Side fences also serve as reinforcement ribs to increase the strength and rigidity of the flap itself.

According to the second aspect of the present invention, if the side fence is formed in a dorsal fin shape extending from the vicinity of the support portion of the flap toward the free end, the side fence of the portion without the steering cylinder side wall becomes large, so that the side fence is increased. Escape of jet flow
The effect of blocking leakage can be improved.

According to the third aspect of the present invention, even if the side fence is partially provided at a portion protruding from the side wall end of the steering cylinder when the flap is raised up horizontally,
It functions as the side fence and contributes to the weight reduction of the device.

According to the fourth aspect of the present invention, the jet stream hitting the flap tends to bounce toward the center of curvature of the circular arc, so that the same action as when the side fence is provided is performed in the front view of the flap. Surface shape ,
The jet flow impinging on the flap is directed to the center of curvature of the arc.
Does not escape outside of the flap
It can be obtained by forming such an arc.

[0012]

[0013]

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are longitudinal sectional views of a water jet propulsion device. FIG. 1 shows a so-called forward full state in which the flap is in a substantially horizontal position, and FIG. 2 shows a case where the hydraulic cylinder is operated to incline the flap by a certain flap angle. FIG. 3 shows a so-called reverse full state in which the flap is in a tilted state in which the flap is tilted to the position of the flow straightening plate. FIG. 4 is a front view of the steering cylinder in FIG. 1 as viewed from the rear.

As shown in FIG. 1, a circular jet nozzle 2 is provided at the rear end of a pump 1 constituting a water jet propulsion device provided at the stern, and a rectangular steering cylinder 5 is provided on the circular jet nozzle 2. It is articulated. That is, the front end of the steering cylinder 5 is pivotally mounted by the upper and lower vertical pins 4 provided on the bracket 3 protruding rearward from the ejection nozzle 2, and the steering cylinder 5 can freely swing horizontally around the vertical pin 4. This operation causes a turning motion of the ship.

A rectangular opening window 6 is formed at one center of the upper wall 5A of the steering cylinder 5. The periphery of the opening window 6 is a flange 6a
Are formed to reinforce the periphery of the opening. An operating shaft 7 is provided horizontally in the lateral direction of the steering cylinder 5 near the opening window 6 so as to face the opening window 6, that is, immediately below the steering cylinder upper wall 5A.
Further, a flap shaft 10 is inserted through the center of the operation shaft 7, and both ends of the flap shaft 10 are supported by the steering cylinder side wall 5B. A lower end of a lever 8 is integrally mounted at a center position of the operating shaft 7, while the lever 8 projects upward from the opening window 6 and extends above the steering cylinder upper wall 5A. The size of the opening window 6 is set larger than the operating range of the lever 8. A hydraulic cylinder 9 constituting a driving device is provided at the upper end of the lever 8.
Rod end 9a is pivotally mounted. The hydraulic cylinder 9 is mounted on a mount 9 b provided at the front end of the steering cylinder 5.
In the above-described configuration, the operating shaft 7, the flap shaft 10, the lever 8, and the hydraulic cylinder 9 are located on the upper portion of the steering cylinder upper wall 5A. water WL ₁ is substantially near the top of the steering tube 5) or died in the sea, never or exposure to sea level. Note that W
L ₂ shows the water surface of the high-speed ocean-going travel time.

An arcuate flap 11 is integrated with the operating shaft 7.
Is installed. Reinforcing ribs 12 are provided on the outer surface of the flap 11 (the surface on which the jet stream does not hit), and its end is integrally fixed to the operating shaft 7. Flap 11
Flap 1 on the inner surface of the
Side fences 13 are provided on both side ends of 1 (FIG. 4). This side fence 13 is a flap supporting portion 11a
And is formed in the shape of a dorsal fin extending toward the free end 11b. In this case, the side fence 13 extends from the flap support portion 11a to near the free end 11b, and a tip portion (free end side) of the side fence 13 is formed in a straight portion (wide portion) 13a to enhance a shielding effect. . As shown in FIG. 2, in a state where the hydraulic cylinder 9 is extended and the flap 11 is set at a certain flap angle (inclined downward) at the time of transition from the forward movement to the reverse movement, the jet flow
After hitting the inner surface, some jet flow
The side fence 13 blocks (blocks) the diverted flow in both side directions to escape. The side fence 13 also serves as reinforcement of the flap 11. In addition, the guide plate 14 may be provided at the center position of the flap or at an appropriate interval for both reinforcing the flap 11 and smoothly guiding the jet flow. A shielding plate 15a is attached to the operating shaft 7 over the entire width of the steering cylinder 5 in the width direction.
3 and a stopper function of the lever 8 to fulfill the stopper function. At the same time, the water flow that has bounced back by the jet flow hitting the flap 11 in the collapsed state as shown in FIG. It also plays a role in shielding from escaping.

On the other hand, a plurality of curved rectifying plates 16 are arranged in a row at the bottom of the steering cylinder 5 as shown in FIG. 3, and when the flap 11 is in a collapsed state, the curved rectifying plate 16a at the distal end position is continuous. As a result, a smooth reverse flow path 17 is formed. These curved rectifying plates 16 have a length sufficient to turn and rectify the jet stream. Reference numeral 18 denotes a circular tube for forming a flow path between the curved straightening plate 16 and the front end of the steering cylinder bottom, and is provided between the steering cylinder side walls 5B. A pair of upper and lower support members 19 are mounted on the circular tube 18, and are supported by the vertical pins 4. When the steering tube 5 is swung horizontally to turn the boat, the jet 18 hits the steering tube side wall 5B and tries to be distorted in the lateral direction, but also plays the role of a rigid member for suppressing it.

When the ship is moving forward, that is, when the hydraulic cylinder 9 is shortened as shown in FIG. 1, the flap 11 rises to a substantially horizontal position and fully opens the rear end opening 5a of the steering cylinder 5, and the jet flow is It is squirted straight back without hitting to generate forward thrust. At this time, since the flap 11 is located above the diameter of the ejection nozzle 2 and the side fence 13 is also located outside (FIG. 4), the ejection of the jet flow is not hindered. When the hydraulic cylinder 9 is extended from the state shown in FIG. 1 and the flap angle is set to the state shown in FIG. 2, the jet flow after hitting the flap 11 does not escape to both sides by the side fence 13 and the flow of the forward thrust flows. The flow is diverted into the backward thrust flow, and the two thrusts are balanced (thlatus 0), and a neutral state is established.

When the vehicle is moving backward, the hydraulic cylinder 9 is further extended and the lever 8 is tilted backward as shown in FIG. 3, so that the flap 11 is inclined and tilted. Curved straightening plate 16a located
To form a continuous, substantially curved reverse flow path 17. The rear opening 5a of the steering cylinder 5 is closed by the flap 11, the jet flow hitting the flap 11 is turned downward, and is ejected by the curved straightening plate 16 in the forward direction of the ship. Get thrust.

FIG. 5 shows the side fence 13 with the flap 11
This is an example in which a part is provided partially in the latter half part. The other elements are the same as those in FIG. 1, and thus the same reference numerals are given and the description thereof will be omitted. The partial side fence 13 in FIG.
When the steering wheel 1 is in the horizontal state, the steering wheel 1 is provided so as to be located at a position protruding from the distal end position of the steering cylinder side wall 5B. However, the vicinity of the base end of the flap 11 slightly overlaps with the side wall 5B. The jet flow diverted to the side after hitting the flap 11 is leaked to the outside by the partial side fence 13 and is prevented from escaping, and the same effect as in FIG. 1 is obtained.

FIG. 6 shows the trajectory 11 c of the tip of the flap 11 instead of providing the side fence.
It is a reference example extended rearward more than (trajectory at the time of transition from forward movement to reverse movement state). Also in this case, the jet flow hitting the flap 11 is prevented from hitting the extended side wall 5B and escaping outside.

FIG. 7 shows a flap 11 formed in an arc shape in a front view, instead of providing a side fence. The jet flow after hitting the arc-shaped flap 11 tends to bounce toward the center of curvature of the arc, preventing the jet flow from escaping from both sides of the flap 11.

[0024]

FIG. 9 shows the change in the thrust (vertical axis) with respect to the flap operation angle (horizontal axis), and the dotted line shows the change when the side fence 13 is provided. Is the result of an experiment with setting to. Note that, as described above, the solid line is a case where there is no side fence (hereinafter, referred to as “conventional one” for convenience).

As shown in FIG. 8, the size of the side fence 13 is set at the flap support center (that is, the flap shaft 10).
The length of the side fence is 0.86 L from the center of support, the depth of the side fence is 0.21 L from the center of support, and the length of the straight part of the tip is 0.2 L. And

In FIG. 9, forward full indicates the state of the flap position in FIG. 1, neutral indicates the state of the flap position in FIG. 2, and reverse full indicates the state of the flap position in FIG. When the flap operation angle is set from forward to reverse, the forward thrust is gradually and smoothly reduced to a greater degree than the conventional one, and the neutral state is reached earlier than the conventional one, that is, at a smaller flap operation angle.

In the prior art, even when the flap is moved to the reverse side, the forward thrust is almost unchanged, and changes rapidly from the forward thrust to the reverse thrust at a certain flap angle. In this mode, the movement of the lever is far from the feeling of maneuvering, and the maneuvering is very difficult and the maneuverability is poor. Therefore,
In particular, when it is necessary to steer while alternately repeating forward and backward movements when approaching or leaving the shore, the advantage of the present application having the side fence is great. When there is a side fence, the forward thrust gradually decreases by taking the flap angle to the reverse side, and there is no sudden transition from the forward thrust to the reverse thrust.
Since reverse thrust is exhibited, it is suitable for maneuvering, easy to maneuver, and excellent in maneuverability and responsiveness. Of course,
When the flap angle is set from the reverse state to the forward side, the same maneuverability and response characteristics can be obtained.

[0028]

According to the first to fourth aspects, the side fence or the arc-shaped flap itself prevents a part of the jet flow hitting the flap from escaping or leaking from both side ends of the flap when shifting from the forward movement to the reverse movement state. Can be blocked by As a result, a smooth decrease in forward thrust corresponding to the flap operation angle (that is, in accordance with a maneuvering sensation), and an increase in reverse flow, whereby the onset of reverse thrust is accelerated, thereby improving reverse responsiveness and reverse performance. Can be. In the first to third aspects, the side fence increases the strength and rigidity of the flap itself.

In particular, if the side fence is formed in a dorsal fin shape extending from the vicinity of the support portion of the flap toward the free end, the side fence at the portion without the steering cylinder side wall becomes large, so that the side fence can be prevented from both sides. Escape of jet flow
The effect of blocking leakage can be improved.

Further, even if the side fence is partially provided at a portion protruding from the side wall end of the steering cylinder when the flap is raised up horizontally,
The effect as the side fence is obtained, which contributes to the weight reduction of the device.

By forming the cross section of the flap into an arc shape as in claim 4, the jet flow hitting the flap tends to bounce toward the center of curvature of the arc, so the side fence is provided. An effect similar to that of the first embodiment can be obtained.

[0032]

[0033]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a steering cylinder including an ejection nozzle in a water jet propulsion device according to the present application, showing a state in which a steering wheel is fully forwarded.

FIG. 2 is a diagram of the neutral state.

FIG. 3 is a diagram of the same reverse full state.

FIG. 4 is a front view of FIG.

FIG. 5 is a longitudinal sectional view of the water jet propulsion device in a case where a side fence is provided in a rear half portion of the flap.

FIG. 6 is a longitudinal sectional view showing a reference example of the water jet propulsion device when the steering cylinder side wall is extended more than the flap tip trajectory.

FIG. 7 is a front view when the flap is formed in an arc shape in a front view.

FIG. 8 is a main part diagram of a flap and the like showing a setting condition of a side fence in an experiment.

FIG. 9 is a diagram illustrating experimental results, and is a thrust change diagram with respect to a flap operation angle when there is a side fence (dotted line) and when there is no side fence (solid line).

FIG. 10 is a side view of the water jet propulsion device without a side fence.

Claims (4)

(57) [Claims] 1. An ejecting nozzle for ejecting a jet stream, a left-right swingable steering cylinder at a rear portion of the ejecting nozzle, and a flap whose one end is rotatably provided at an upper portion of the steering cylinder. flap, the reverse state is formed to close the rear opening of the steering cylinder is inclined fallen state, and open the rear opening of the steering cylinder is in a state of getting up in a substantially horizontal transfected
In both least water jet propulsion unit that a portion thereof to form a forward drive state is exposed to the rear from the steering cylinder, at both ends of the inner surface of a jet stream of the flap hits, the
The jet stream that hits the flap splits in both directions and
A reversing device for a marine water jet propulsion device, comprising a side fence for preventing escape from both sides of the flap . 2. The marine water jet propulsion device according to claim 1, wherein the side fence is formed in a shape of a back fin extending from a vicinity of a support portion of the flap toward a free end. 3. The side fence is partially provided in the rear half of the flap, and the partial side fence protrudes from the end of the side wall of the steering cylinder when the flap is raised up horizontally. Reverse gear for marine water jet propulsion. 4. An ejecting nozzle for ejecting a jet stream, a left and right swingable steering cylinder at a rear portion of the ejecting nozzle, and a flap whose one end is rotatably provided at an upper portion of the steering cylinder. flap, the reverse state is formed to close the rear opening of the steering cylinder is inclined fallen state, and open the rear opening of the steering cylinder is in a state of getting up in a substantially horizontal transfected
In a water jet propulsion device in which at least a part thereof is exposed rearward from the steering cylinder to form a forward state, the cross-sectional shape of the flap is applied to the flap in a front view.
Jet stream bounces toward the center of curvature of the arc and
A reversing device for a marine water jet propulsion machine, which is formed in an arc shape so that a jet stream does not escape outside a flap .