JPH0520640Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a reversing mechanism for a waterjet propulsion system for ships, which is often used in high-speed boats and the like.

(b) Conventional technology This kind of waterjet propulsion system does not have as much external resistance as a propeller propulsion system, so it can achieve high speeds, can navigate in shallow waters and areas with many reefs, and has low noise and vibration. Recently, it has become popular mainly in high-speed lifeboats and leisure boats.

The principle of this waterjet propulsion system is that an intake duct is installed from the bottom of the ship to the stern to draw water in, and a high-speed water flow is generated within this intake duct using an axial flow pump or a mixed flow pump, which is then pumped through the intake duct. Propulsive force is obtained by ejecting water from a steering nozzle installed at the end. By changing the direction of this water flow in the horizontal and vertical planes,
This allows for steering and speed adjustment (including forward and backward conversion).

By the way, as a structure for changing the jetting direction of this water flow, there is a structure shown in Japanese Patent Application Laid-open No. 170695/1983. In other words, an overflow port is formed at the bottom of the steering nozzle, which has its rear end opened and serves as a spout for the water flow that is ejected rearward. Two movable buckets are installed, and the amount of water flowing backwards is dammed and the amount of water directed forward is adjusted according to the rotation angle of the buckets.

(c) Problems that the invention aims to solve However, in this prior example, the bucket installed in the nozzle to dam the water jet is cantilevered from its mounting part, so its deformation occurs. It was necessary to make it very stiff to prevent vibrations. Therefore, the weight increased and a large amount of power was required. Furthermore, when the bucket tot rises, the bucket itself rises while moving forward against the flow of water, which also requires a large amount of power.

(d) Means to solve the problem Therefore, in this invention, an overflow port is formed on the bottom of the steering nozzle which opens at the rear end and serves as a spout for the water flow spouted rearward, and the top and bottom of the overflow port are Two buckets are installed at the rear of the overflow port and rotate around support shafts, and the amount of water flowing backwards is dammed and diverted forward depending on the angle of rotation of these buckets. In the reversing mechanism of the waterjet propulsion device, links are connected to the middle of each bucket, and these buckets and links form a parallelogram link mechanism, and the bucket can be rotated by expanding and contracting this parallelogram link mechanism. The present invention provides a reversing mechanism for a waterjet propulsion device, which is characterized by the following features:

(E) Effect By taking the above measures, both the upper and lower buckets are supported at two points: the support shaft, which is the fulcrum, and the link connected to the middle of the support shaft, so that deformation thereof is also suppressed. In addition, since the bucket can be opened and closed (rotated) by expanding and contracting the parallelogram link mechanism, the rotation angle of the upper and lower buckets is the same, and the direction of the water flow can be changed smoothly.

(F) Embodiment An embodiment of this invention will be described below with reference to the drawings. Figures 1, 2, and 3 show the steering nozzle portion of a waterjet propulsion device having a reversing mechanism according to this invention. Longitudinal sectional view, 4th
The figure is a longitudinal sectional view of the steering nozzle portion of another embodiment, FIG. 5 is a longitudinal sectional view of the entire water jet propulsion device, and FIG. 6 is a plan view of the steering nozzle portion.

First, the outline of the waterjet propulsion device will be explained with reference to FIG.

The inflow part A is a part that takes in water, and has a water intake 1 at its starting end, which extends slightly diagonally upward, then becomes almost straight and extends rearward (the rear end protrudes from the stern). An intake duct (hereinafter referred to as duct) 2 is provided.

The pump part B is a part that pressurizes water sucked into the duct 2, and an impeller 4 driven by a drive shaft 3 is installed near the rear end of the duct 2.

The discharge part C is a part that guides and discharges water pressurized by the impeller 4 backward as a rotating high-speed water stream (jet stream), and has a guide vane 5 fixed to the inner peripheral side of the duct 2. , the diameter of the duct 2 itself is narrowed down to form a nozzle 6. Note that the center core of the guide vane 5 is connected to the bearing portion 7 at the rear of the drive shaft 3.
In addition, a guard grid 8 is installed near the suction end of the duct 2 to remove floating objects such as dust.

The jet direction control section D is a section that controls the left and right and up and down directions of the jet jet ejected from the discharge section C.
That is, a steering nozzle (hereinafter referred to as a nozzle) 9 is connected to the rear of the nozzle 6 of the discharge part C by a pin 10, so that the steering nozzle (hereinafter referred to as a nozzle) 9 can be freely rotated in the left and right directions about this nozzle. Therefore, duct 2
If two left and right hydraulic cylinders 11 are installed in the nozzle 9 section, the nozzle 9 can be tilted left and right by extending and contracting each hydraulic cylinder 11, thereby making it possible to steer the vehicle. (See Figure 6). Furthermore, this jet flow direction control section D is provided with the following reversing mechanism 12. That is, in addition to forming an overflow port 13 on the bottom surface near the rear end of the nozzle 9 that allows the jet to overflow, the jet is dammed at the top and bottom of the overflow port 13 according to the upright angle.
In addition, two buckets 14 are rotatably provided to cause the water to overflow from the overflow port 13 and change its direction forward. By the way, regarding the rotating structure of this bucket belt 14, the following parallelogram link mechanism 15 is used in this invention. That is, first, a horizontal support shaft 16 is fixedly mounted behind the overflow port 13, and the upper and lower buckets 14 are rotated around this support shaft 16.
be able to rotate (up and down) symmetrically.
Next, one end of each link 20 is connected to the middle of the bucket 14, and the other end is connected by a connecting pin 24, so that the bucket 14 and the links 20 form a parallelogram link mechanism 15.
On the other hand, hydraulic cylinders 17 are installed at both rear ends of the nozzle 9.
A swing arm 18 that can be rotated back and forth by expansion and contraction is provided, and a slide lever 19 is pivotally connected to this swing arm 18, and this slide lever 19 is connected to a connecting pin 24 of a link 20. At this time, a long hole 21 is formed in the slide lever 19, and this is used as a guide when the slide lever 19 is inserted into the guide pin 22 and slid (see FIGS. 1 to 3).

As described above, when the hydraulic cylinder 17 is extended and the slide lever 19 is slid forward via the swing arm 18, the bucket 14 falls down above and below the overflow port 13, blocking the overflow port 13, and the nozzle 9 The interior is fully opened and all the jets flowing through it are ejected backwards from the spout 23 at the rear end (see Figure 1), so at this time it moves forward at maximum speed. On the other hand, if the slide lever 19 is slid backward, the buckets 14 will stand above and below the overflow port 13, and the upper bucket 14 will block the flow of the jet inside the nozzle 9. In addition, the thus blocked jet flow is guided downward through the overflow port 13 and is further reversed forward by the lower bucket 14 (see Fig. 3), so this is the time to move backward at maximum speed. Note that by performing operations in between these (see Figure 2), it becomes possible to adjust the speed and switch between forward and reverse directions.

In the parallelogram link mechanism 15 described above, the upper and lower buckets 14 rotate around the fixed support shaft 16, so when the buckets 14 open, they do not move forward, but instead receive increased water pressure. It has the advantage of being less intense. On the other hand, FIG. 4 shows another embodiment of the parallelogram link mechanism 15, but in this example, both links 20, which are pivoted to the upper and lower buckets 14, are supported at one point. pin 2
4 is of a fixed type, and a support shaft 16 connecting both bucket belts 14 is connected to a swing arm 18. This structure has the advantage that the slide lever 19 and the like are not required and the structure is simple.

(g) Effects of the invention Since this invention is as described above,
In other words, the bucket is supported at two points: the support shaft at the center of rotation, and a link connected to the middle of the shaft, so the force from the water flow is shared between these two points, making it lightweight and low-rigidity. Even if there is a problem, deformation and vibration can be prevented. In addition, since the bucket and the links form a parallelogram link mechanism, the rotation angle is the same both up and down, making it possible to smoothly change the direction of the water flow.

[Brief explanation of the drawing]

1, 2, and 3 are longitudinal sectional views of a steering nozzle portion of a waterjet propulsion device having a reversing mechanism according to this invention, and FIG. 4 is a longitudinal sectional view of the same steering nozzle portion of another embodiment. , FIG. 5 is a longitudinal sectional view of the entire water jet propulsion device, and FIG. 6 is a plan view of the steering nozzle portion. Symbol, 9... Steering nozzle, 13... Overflow port, 14... Bucket, 15... Parallelogram link mechanism, 16... Support shaft, 17... Hydraulic cylinder, 19... Slide lever, 20... Link,
23... spout, 24... connecting pin.

Claims (1)

[Scope of Claim for Utility Model Registration] An overflow port 13 is formed on the bottom surface of the steering nozzle 9, which has its rear end opened and serves as a water jet port 23 for ejecting water backward. Two buckets 14, 14 are provided which rotate around a support shaft 16 provided at the rear of the bucket, and depending on the rotation angle of these buckets 14, 14, the amount of water jetting backward is dammed and the direction is changed forward. In the reversing mechanism of the water jet propulsion device for adjusting the water jet propulsion device, links 20 and 20 are connected to the middle of the bucket belts 14 and 14, respectively, and these bucket belts 14 and links 20 and 20 constitute a parallelogram link mechanism 15. A reversing mechanism for a water jet propulsion device, characterized in that the buckets 14, 14 are rotated by expanding and contracting the parallelogram link mechanism 15. While fixing the support shaft 16, the link 2
Claims for registration of a utility model characterized in that a slide lever 19 is connected to a connecting pin 24 that connects 0 and 20, and the slide lever 19 is moved back and forth by a hydraulic cylinder 17 to expand and contract the parallelogram link mechanism 15. A reversing mechanism of the waterjet propulsion device according to item 1. Utility model registration claim 1, characterized in that the parallelogram link mechanism 15 is expanded and contracted by fixing the connecting pin 24 that connects the links 20, 20 and moving the support shaft 16 back and forth with a hydraulic cylinder 17. Reversing mechanism of the described waterjet propulsion device.