JPH09104393A - Backing device for water jet type propelling machine for ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backing device for a ship propelling machine of water jet type, with which a backing situation is formed with the jet stream from a nozzle suppressed and also the bow turning performance is enhanced. SOLUTION: A water jet type propelling machine has a fulcrum for a flap 11 rotating in the upper part of a steering cylinder 5 and forms the reversing condition in cooperation with a baffle plate 14 furnished at the bottom of the steering cylinder while the jet stream spouted out of a nozzle 2 is suppressed, wherein an end part bottom plate 15 protruding inward from the side wall 5B of the steering cylinder is installed at the top of the baffle plate 14 so that a jet stream shutting area is formed along the side wall 5B, and thereby the jet stream at steering is prevented from running away downward from an opening 5C provided in the cylinder bottom, which should ensure that the steering performance is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention according to the present application relates to a water jet propulsion machine having a flap rotation fulcrum on an upper portion of a steering cylinder and forming a reverse state while suppressing a jet flow from an ejection nozzle. Regarding the reverse gear, more specifically, when the steering cylinder is swung in order to turn the ship in the forward traveling state, the amount of jet flow hitting the side wall of the steering cylinder escapes from the bottom opening of the steering cylinder to reduce the steering effect. The present invention relates to a reverse drive device for a marine water jet propulsion machine with enhanced steering force.

[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. 5, the pivot support point 52 of the flap 51 is attached to the steering cylinder 5
It is located at the top of 3 and has a flap 51 when moving from forward to reverse.
Is operated to an inclined tilted state indicated by an imaginary line to suppress the jet flow emitted from the jet nozzle 54 and shift from the forward movement to the reverse movement. The other one is
There is a pivotal support point of the flap as described in JP-A-5-278683 in the lower part of the steering cylinder, and the flap is operated up to an inclined upright state to sequentially cut off the jet stream, and the jet stream is advanced from the reverse direction. It is a form of moving to.

In either type, when the ship is turned in the forward state, the steering cylinder is horizontally swung to jet the jet stream obliquely backward to generate a turning moment.

In the latter type, since the flap is located on the straightening vane and closes the opening of the bottom portion of the steering cylinder in the forward traveling state, a part of the jet flow hitting the side wall of the steering cylinder will not escape from the bottom portion. Absent.

[0005]

However, in the former type (FIG. 5), the flap is in the horizontal position above the steering cylinder and the steering cylinder bottom opening 55 is open during forward movement. When the steering cylinder 53 shown in FIG.
The jet flow colliding with a is jetted rearward, and a part of the jet flow is dispersed above and below the steering cylinder 53. The upward shunt is blocked by the flap 51, while the downward shunt escapes and leaks from the steering cylinder bottom opening 55. As a result, the entire amount of jet flow cannot be ejected rearward effectively, so that the steering effectiveness is reduced and the steering force is weakened.

When the jet flow leaks from the opening 55 at the bottom of the steering cylinder, the flow is bent by a plurality of straightening vanes 56 arranged in line at the bottom of the steering cylinder.
A force F as shown in FIG.

Here, F = ρQVsinβ (ρ: density of seawater, Q: flow rate, V: flow velocity). This force F acts on each of the straightening vanes 56, and the sum thereof becomes a force in a direction opposite to the forward force by the jet flow. As a result, it is added that the forward force is reduced and the forward force is reduced due to the leakage of the jet flow, the steering efficiency is further reduced, and the turning performance of the ship is reduced.

The invention according to this application is a water jet propulsion machine of the type in which a pivot fulcrum of a flap is provided on an upper portion of a steering cylinder and a backward movement state is formed while suppressing a jet flow emitted from an ejection nozzle. An object of the present invention is to provide a reverse drive device for a water jet propulsion device for a marine vessel, in which leakage of jet flow from the bottom of a steering cylinder is reduced to improve steering efficiency and to improve the turning performance of a ship.

[0009]

[Means for Solving the Problems] A means for achieving the above object is to provide a jet nozzle for jetting a jet stream and a steering barrel which is swingable to the left and right at the rear of the jet nozzle, and which is provided above the steering barrel. Is provided with a flap whose one end is rotatably supported, and when the flap is in a tilted state, a rearward passage is formed by closing a rear opening of the steering cylinder and a plurality of straightening plates provided on the bottom of the steering cylinder. In addition, it is premised on a water jet propulsion machine which opens the rear opening of the steering cylinder to form a forward state in a state where the steering cylinder rises substantially horizontally.

According to the first to fifth aspects of the present invention, an end bottom plate protruding inward from the steering cylinder side wall is provided at the upper end position of the straightening vane to form a jet flow shielding area along the side wall. During steering, jet flow is prevented from leaking and escaping downward from the bottom opening of the steering cylinder as much as possible.

In this case, like the means of claim 2, an end bottom plate having a constant width may be installed between the upper ends of the foremost and rearmost straightening vanes, and particularly, as in the means of claim 3. , The relationship between the lateral width A of the steering cylinder and the width B of the end bottom plate is B / A = 0.
If it is set to about 1, the balance between the steering force and the reverse force is secured.

Further, as in the means of claim 4, by making the width of the end bottom plate wider in the rear portion than in the front portion of the steering cylinder, the escape of the jet stream downward during steering can be further reduced. , Further enhance the steering force and improve the turning performance.

Further, as in the means of claim 5, the end bottom plate is provided so as to be inclined downward toward the rear of the steering cylinder, so that the jet flow and the end bottom plate tend to diffuse toward the rear of the steering cylinder. Interference with can be avoided.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a vertical cross-sectional view of the water jet propulsion device, FIG. 2 is a plan view of the bottom portion, and FIG. 3 is a front view of the propulsion device seen 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 portion of the steering barrel 5 is pivotally attached by the upper and lower vertical pins 4 provided on the bracket 3 protruding rearward from the ejection nozzle 2, so that the steering barrel 5 can swing around the vertical pin 4 in the horizontal plane. This movement (steering) causes the turning motion of the ship.

A rectangular opening window 6 is provided at a central portion of the upper wall 5A of the steering cylinder 5, and the peripheral edge portion of the opening window 6 is a collar 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 operating shaft 7, and both ends of the flap shaft 10 are pivotally supported by the steering cylinder side wall 5B (FIG. 2). 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 rod end 9a of a hydraulic cylinder 9 that constitutes a drive device is pivotally attached to the upper end of the lever 8, and the hydraulic cylinder 9 is mounted on a mount 9b 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 above the steering cylinder upper wall 5A, and even when the boat is stopped or running at low speed (at this time, The water surface WL ₁ is almost in the vicinity of the upper part of the steering tube 5) It is not submerged in the sea or exposed to the sea water surface. It should be noted, WL ₂ shows the water surface of the high-speed ocean-going travel time.

An arcuate flap 11 is integrally mounted on the actuating shaft 7, and a reinforcing rib 12 is provided on the back surface of the flap 11 (the surface against which the jet flow does not hit).
The end portion is integrally fixed to the operating shaft 7. Further, the shield plate 13a is provided on the operation shaft 7 over the entire width direction of the steering cylinder 5.
Is attached to the vertical pin 4, and is a support plate 13b pivotally attached to the vertical pin 4.
And the stopper function of the lever 8,
The jet flow hits the flap 11 in the collapsed state and also plays a role of blocking the water flow that has rebounded from escaping upward from the opening window 6.

A plurality of curved straightening vanes 14 are arranged in a row at the bottom of the steering barrel 5, and when the flap 11 is in a tilted state (shown by phantom lines), the straightening vanes 14a at the tip position are continuously connected. Therefore, a smooth reverse flow path is formed. These straightening vanes 14 are long enough to divert and straighten the jet flow.

At the upper end of the rectifying plate 14, an end bottom plate 15 horizontally projecting inward from both side walls 5B of the steering cylinder 5 is provided. The end bottom plate 15 extends in the longitudinal (front-rear) direction of the steering cylinder 5 so as to connect the upper ends of the plurality of straightening vanes 14 to each other. The end bottom plate 15 forms a jet flow shielding area inside the steering cylinder, and prevents jet flow from escaping downward from the steering cylinder bottom opening 5C during steering in a forward drive state to improve the steering effect (steering force). Let It is effective that the end bottom plate 15 is provided above the straightening vanes 14 to dam the jet flow before entering between the straightening vanes 14, and even if it is provided at the lower end of the straightening vanes 14, the jet flow escapes downward. It has been confirmed by experiments that it is significantly reduced.

By providing the end bottom plate 15, the reverse force is reduced because the end bottom plate 15 becomes a resistance when moving backward, but in FIG. 2, A is the lateral width of the steering cylinder 5, and B is the end bottom plate 15. Assuming that the width is B / A = 0.
It has been confirmed by experiments that if the value is set to about 1, the size and shape will be such that both the reverse force and the steering force can be balanced. As shown in FIG. 1, if the upper end position of the straightening vane 14 is provided so as to be inclined downward as it goes rearward, the end bottom plate 15 is inclined downward and the straightening vane 1 from the frontmost portion to the rearmost portion is formed.
It will be installed between four. This is to avoid the jet flow from interfering with the end bottom plate 15 because the jet flow tends to diffuse toward the rear of the steering cylinder 5.

The end bottom plate 15 shown in FIG. 2 has a constant width, but instead of this, the width of the end bottom plate 15 is changed toward the rear of the steering cylinder 5 as shown in FIG. It is possible. In FIG. 4, the edge line 15a of the end bottom plate 15 is substantially the origin of the rear end of the steering cylinder 5 with respect to the center line O of the steering cylinder 5 so that the width of the end bottom plate 15 suddenly increases at the rear part of the steering cylinder 5. It is shaped like a parabola. That is, in normal steering, the steering angle (the swinging angle of the steering cylinder) is set to about 15 ° to the left and right, and the steering angle is not increased more frequently.
When the steering angle is small, the jet flow collides with the rear part of the steering tube. Therefore, if the width of the rear part of the end bottom plate 15 is wide as shown in FIG.
Since the amount of jet flow escaping downward from C can be effectively reduced, the amount jetted rearward increases and the steering effect is further improved.

When the boat 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 5D of the steering cylinder 5, so that the jet flow is generated. It ejects straight backwards without hitting the butt and generates forward thrust. At this time, the flap 11 is provided so as to be located above the diameter of the jet nozzle 2 and does not interfere with jetting of the jet flow. Further, if the end bottom plate 15 is provided so as to be inclined rearward, the two do not interfere with each other even if the jet flow tends to diffuse toward the rear.

When the steering cylinder 5 is swung in order to steer (turn) the ship in the forward state, the jet flow hits the steering cylinder side wall 5B and then a part of the jet flow is jetted from the rear opening 5D along the side wall 5B. . A part of the flow splits upward along the side wall 5B, hits the flap 11, and then jets backward. Further, a part of the flow splits downward along the side wall 5B and a part leaks from the bottom opening 5C, but the flow along the side wall 5B hits the end bottom plate 15 and is ejected rearward. Thus, most of the jet flow at the time of steering is ejected rearward, so that the steering effect is improved and the turning performance is improved.

When the vehicle is moving backward, the hydraulic cylinder 9 is extended and the lever 8 is tilted backward so that the flap 11
Is in an inclined and tilted state (phantom line in FIG. 1), and the arcuate flap 11 engages with the rectifying plate 14a located at the rearmost portion to form a continuous substantially curved backward passage. The rear opening 5D of the steering cylinder 5 is closed by the flap 11, the jet flow that hits the flap 11 is diverted downward, and is jetted in the forward direction of the ship by the straightening vane 14, and the reaction force of the jet causes the ship to produce a reverse thrust. obtain.

[0025]

According to the first to fifth aspects of the invention, the jet flow shielding region is formed inside the steering cylinder side wall, whereby the jet flow leaking and escaping downward from the steering cylinder bottom opening at the time of steering (steering cylinder swing). The amount is reduced, the steering force is strengthened accordingly, the steering efficiency is improved, and the turning performance can be improved.

As in the second aspect, the same effect can be obtained by installing the end bottom plate having a constant width between the upper ends of the front and rearmost flow regulating plates.

In particular, as in claim 3, the lateral width A of the steering cylinder
By setting the relationship between B and the width B of the end bottom plate to about B / A = 0.1, it is possible to secure the balance between the steering force and the reverse force.

According to the present invention, in the rear portion where the width of the end bottom plate is widened, it is possible to reduce the downward leakage amount of the jet flow during steering, further enhance the steering force, and improve the steering effect.

According to the fifth aspect, it is possible to avoid the interference between the jet flow and the end bottom plate, which tends to diffuse toward the rear of the steering cylinder.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a water jet propulsion machine according to the invention of the present application, which is a view in a forward state.

FIG. 2 is a sectional view of the bottom.

FIG. 3 is a front view of the propulsion device as viewed from the rear.

FIG. 4 is a bottom cross-sectional view of the same propulsion machine showing a modified example of the end bottom plate.

FIG. 5 is a side view of a water jet propulsion machine for showing a conventional technical problem.

FIG. 6 is a bottom plan view when the steering cylinder is horizontally swung (during steering).

FIG. 7 is an explanatory diagram of a force that acts on a current plate by a jet flow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pump 2 ... Jet nozzle 5 ... Steering cylinder 5A ... Steering cylinder upper wall 5B ... Steering cylinder side wall 5C ... Steering cylinder bottom opening 5D ... Steering cylinder rear opening 6 ... Opening window 7 ... Operating shaft 8 ... Lever 9 ... Hydraulic cylinder 10 ... flap shaft 11 ... flap 14 ... straightening plate 15 ... end bottom plate

Claims (5)

[Claims] 1. A jet nozzle for jetting a jet flow, a left and right swingable steering cylinder at a rear portion of the jet nozzle, and a flap having one end rotatably supported on an upper portion of the steering cylinder. When the flap is tilted, the rear opening of the steering tube is closed to form a reverse flow path with a plurality of straightening plates provided on the bottom of the steering tube, and when the flap is raised substantially horizontally, the rear opening of the steering tube is closed. In a water jet propulsion device for opening a vehicle to form a forward movement state, an end bottom plate protruding inward from a side wall of a steering cylinder is provided at an upper end position of the rectifying plate, and a reverse device for a marine water jet propulsion device. 2. The reverse device for a marine water jet propulsion machine according to claim 1, wherein an end bottom plate having a constant width is provided between the upper ends of the foremost and rearmost rectifying plates. 3. The end bottom plate is provided with a constant width, and the relationship between the lateral width A of the steering cylinder and the width B of the end bottom plate is set to about B / A = 0.1. A reverse device for a marine water jet propulsion machine according to claim 1 or 2. 4. The reverse drive device for a marine water jet propulsion apparatus according to claim 1, wherein the width of the end bottom plate is widened from the front part to the rear part of the steering cylinder. 5. The reverse drive device for a marine water jet propulsion device according to claim 1, wherein the end bottom plate is provided so as to be inclined downward toward the rear of the steering cylinder.