JPS58139895A - Water jet propulsion ship - Google Patents

Abstract

PURPOSE:To prevent inside wall parts of ducts, a pump impeller or the like from being fouled by underwater organisms, by a method wherein an air-ejecting means for replacing water in a water jet ejecting duct with air when the ship is anchored is connected to the duct. CONSTITUTION:When anchoring the ship, a hydraulic cylinder 10 is stretched to move a movable rear half part 11'b of a stationary blade boss part 11' backwards so that a water jet ejecting port 7 is closed by the rear half part 11'b. Under this condition, an air pump 14 is operated to feed air into the duct 6 through an air-injecting port 13, whereby water in the duct 6 is replaced by air. As a result, the water level in the duct 6 is lowered to the position indicated by numeral 15, so that water is completely drained form the duct 6, whereby fouling due to adhesion of underwater organisms can be provented. Accordingly, reduction in propelling efficiency due to fouling can be also prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ship that can be propelled by jetting water jets from the rear end of its stern.

As a conventional water jet propulsion vessel, there is one as shown in Fig. 1, in which a water jet is ejected from the rear end of the stern section by ascending and tilting rearward from the water intake port 6a at the bottom of the vessel. A water jet ejection duct 6 leading to the lower part is provided, and a pump rotor 4 is disposed in the rear part of the duct 6.

Note that the pump rotor 4 is connected to the main engine 2 via the drive shaft 3.

Further, a fixed boss portion 11 is provided behind the pump rotor 4.
A stator vane 5 with an attached is provided.

Therefore, by rotating the pump rotor 4 by the main engine 2, water is sucked into the outer tank from the water intake 6a, and a high-speed water jet is ejected from the water jet spouting lower, so as a result of the reaction, The ship is now propelled.

Further, the control device 8 can be swung left and right, thereby changing the direction of the water jet and changing the direction of travel of the ship.

However, in such conventional water jet propulsion vessels, when the vessel is at rest, the center of the drive shaft 3 is often aligned with the still water surface 9, or is submerged underwater.
Water often enters the inside of the duct 6, and this causes aquatic organisms to adhere to the inner surface of the duct, the inner surface of the water jet lower, or the pump rotor vane or stationary blade 5, causing contamination. There is a problem. In the vicinity of the still water surface 9, the contamination is particularly significant.

In addition, it is difficult to clean the inside of the duct 7, and therefore, if the inside of the duct 7 becomes dirty, the frictional resistance due to this will rapidly increase, resulting in a significant reduction in propulsion efficiency. There is a point.

The present invention is an attempt to solve the above-mentioned problems.The present invention is aimed at solving the above-mentioned problems by draining the water inside the duct when the ship is stopped, thereby preventing the inside of the duct, pump rotor, stationary blades, etc. from being contaminated by aquatic organisms. The purpose of the present invention is to provide a water jet propulsion vessel that can prevent the above problems.

For this reason, the water jet propulsion boat of the present invention is provided with a water jet spouting duct that ascends and slopes rearward from the water intake in the bottom of the stern to the water jet spout at the rear end of the stern, and also has a duct in the rear of the duct. The pump has a companion pump moving impeller disposed at the pump moving vane, and a stator vane provided at the rear of the pump moving impeller, and the boss section of the stator vane is composed of a fixed front half part and a movable rear half part, An actuator is provided that can move the movable rear half of the stationary vane boss back and forth in order to open and close the water jet outlet.

The ship is characterized in that an air jetting means for replacing the water in the duct with air when the ship is stopped is connected to the duct.

Hereinafter, a water jet propulsion boat as an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is an explanatory diagram showing the stern part of the boat.

The same reference numerals as in FIG. 1 indicate substantially similar parts.

Now, in the case of a single water jet propulsion vessel, the stern part of the hull 1
A is provided with a water jet spouting duct 6 that ascends and slopes rearward from the water intake 6a on the bottom of the ship to the water jet jet [J7] at the rear end of the stern section. A pump rotor wheel 4 is provided which is rotatably driven by the main engine 2I/C via 31.

Also, behind this pump rotor 4.

Stator blades 5 are provided.

By the way, it is composed of the boss part 11'ij of the stator vane 5, a fixed front half part 11'a with the stator vane 5 attached, and a movable rear half part 11'b. Movable rear half 11't)f: A hydraulic cylinder 1O is provided as an actuator that can move it back and forth.

Then, U to the hydraulic cylinder lO, control valve A1.6゜1
A hydraulic pump 12 is connected via 7.

Therefore, the hydraulic cylinder 10 is extended.

When the movable rear half 11'b is moved rearward, the movable rear half 11/b closes the water jet spout lower.

Conversely, by contracting the hydraulic cylinder lO, the movable rear half 11'
When b is moved forward, this movable rear half 11'bij
Open the water jet spout Roman.

In addition, as the movable rear half part 11'b moves forward, the movable rear half part 11'b and the fixed front half part 11'a form an integral boss part 11'.

Further, an air inlet 13 is formed in the duct 6, and the air inlet 13Fi is connected to an air pump 14 constituting air jetting means.

Therefore, by operating the air pump 14 and blowing out air from the air inlet 13 with the water jet spout lower closed by the movable rear half 11'b of the stator vane boss 11', the inside of the duct 6 can be of water can be replaced with air.

With the above-mentioned configuration, when the ship is stopped, the hydraulic cylinder 10 is extended to move the movable rear half 11'b of the stator vane boss 11' rearward, and the movable rear half 11'b operates the lower water jet jet. Keep it closed. In this state, the air pump 14 is operated to inject air into the duct 6 through the air inlet 13, thereby replacing the water in the duct 6 with air.

As a result, the water level inside the duct 6 drops to the position indicated by reference numeral 15, so that water disappears from inside the duct 6, thereby preventing the occurrence of contamination due to adhesion of aquatic organisms.

Therefore, a decrease in propulsion efficiency due to this contamination can also be prevented.

It was a cabinet. During ship maneuvering, the hydraulic cylinder 10 is contracted to integrate the stationary vane boss part 11' with the fixed front half part 11'b.
The shape is the same as that of the conventional stator vane boss portion 11 shown in FIG.

At this time, the water jet lower is open.

Since the shape of the stator vane boss portion 11' is also the same as that of the conventional one, there is no reduction in propulsion efficiency during navigation.

As described in detail above, according to the water jet propulsion vessel of the present invention, the water in the duct is discharged and replaced with air when the vessel is stopped. etc. can be sufficiently prevented from being contaminated by aquatic organisms, which has the advantage of preventing a decrease in propulsion efficiency due to this staining.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the stern section of a conventional water jet propulsion boat, and FIG. 2 is an explanatory diagram showing the stern section of the water jet propulsion boat of the present invention. 1. Hull, la. Stern, 2. Main engine. 3. Drive shaft, 4. Pump rotor, 5. Stationary blade, 6.
・Water jet spout duct, 6a.. Water intake, 7.. Water jet spout, 8.. Control device, 9.. Still water surface, 10.
...Hydraulic cylinder as actuator, 11'...
Stator blade boss section. 11'a... Fixed front half of stator vane boss part, 11'b... Movable rear half part of stator vane boss part, 12... Hydraulic pump, 13...
Air inlet, 14. Air pump constituting air jetting means, 15. Water surface, 16° 17. Control valve. Sub-Agent Patent Attorney Yoshihiko Iinuma

Claims (1)

[Claims] A water jet jet duct is provided that ascends and slopes rearward from the water intake in the bottom of the stern to the water jet outlet at the rear end of the stern, and a pump rotor and a pump are installed in the rear of the duct. The stator vane is provided behind the moving blade wheel, and the boss part of the stator vane is composed of a fixed front half part and a movable rear part, and the stator vane is arranged to open and close the water jet outlet. The vessel is characterized by being provided with an actuator that can move the movable rear half of the boss portion back and forth, and connected to the duct with air jetting means for replacing the water in the duct with air when the ship is stopped. Water jet propelled ship.