JPH0694279B2 - Water jet propulsion device inlet structure - Google Patents

Description

The present invention relates to a suction port structure of a water jet propulsion device for a small jet propulsion ship.

[Prior Art] As a water jet propulsion device for a small jet propulsion ship, Japanese Patent Laid-Open No.
There is one described in Japanese Patent Publication No. 2996. This water jet propulsion device is arranged in the duct, a water suction port opened in water, a jet port for jetting water to obtain a reaction force, a duct connecting the water suction port and the jet port, and It has an impeller for sucking through the suction port and ejecting it as a jet from the ejection port, and a casing that pivotally supports the impeller and that constitutes at least the rear edge portion of the duct and the water suction port. Then, in the suction port structure, a lattice including a plurality of lattice members extending in the front-rear direction and spaced from each other is arranged outside the water suction port.

Here, the spacing of the lattice members is to ensure the function of sucking water from the water suction port and the function of jetting water from the jet port.
It cannot be made too narrow, so leaving a certain distance between the grid members results in the inhalation of wood particles floating on the water surface, seabed pebbles and debris when traveling in shallow water into the water inlet. In this case, the wood chips, pebbles, and debris collide with the trailing edge of the water suction port due to the relative speed with the ship speed. Therefore, the trailing edge portion of the water suction port may be deformed or damaged and the water suction performance may be deteriorated. Therefore, the peripheral wall forming the water suction port has to be replaced relatively frequently.

Therefore, there is one described in JP-A-56-75295.
This is done by bending one of the grid members on the outside of the grid and welding it to the other grid member to extend along the trailing edge of the water inlet, thereby It is intended to protect the tip.

[Problems to be Solved by the Invention] However, according to this structure, only the projection of the trailing edge of the water suction port can be protected, but the rubble or the like that enters between the grid members and enters the duct. Does not protect the peripheral wall of the water suction port when it collides inward with respect to the tip of the trailing edge.

The present invention has been made in view of the above-mentioned problems of the conventional art, and the object thereof is to provide a peripheral wall of the water suction port,
(EN) It is intended to provide a suction port structure of a water jet propulsion device which can effectively protect foreign matter from entering between the lattice members.

[Means for Solving the Problems] In order to achieve the above object, the present invention is equipped with a protective cover having a substantially U-shaped cross section in the ship longitudinal direction so as to cover the rear edge of the peripheral wall of the water suction port. Is.

[Operation] With this configuration, since the rear edge of the peripheral wall of the water suction port is covered with the protective cover, the captain can handle foreign matter such as rubble that enters from between the lattices arranged outside the water suction port. The trailing edge of the acute-angled cross section in the hand direction is effectively protected.

[Examples] The present invention will be described below based on Examples shown in the drawings.

1 to 4 show a first embodiment of the present invention, which is applied to a small water jet type leisure ship.

A water injection type small leisure boat 10 has a water injection unit 16 mounted on the lower rear portion of a hull 12, while an engine 14 is mounted via a vibration damper 15 on the front side of the center of the hull 12. Further, the fuel tank 22 is arranged near the center of the hull.

The water injection unit 16 mainly includes an impeller 18 that receives the rotational power of the engine 14 via a propeller shaft 20 and rotates, and a ship bottom 17
That is, a water suction port 24 that opens into water and sucks water by the impeller 18, a jet port 26 that jets the sucked water as a jet flow by rotation of the impeller 18, and a vane 28 that is provided on the downstream side of the impeller 18. And consists of. Reference numeral 30 is an elastic coupling for connecting the crank shaft (not shown) of the engine 14 and the propeller shaft 20, and 32 is an aluminum for enclosing the impeller 18 and forming a duct connecting the water suction port 24 and the jet port 26. A casing made of alloy casting, 34 is a handle device 36
It is a steering nozzle that interlocks with and changes the jet direction of the jet flow from the jet outlet 26 to steer the ship.

A more detailed structure of the water injection unit 16 is shown in FIG. 2, in which the front end of the propeller shaft 20 is the hull 12
It extends through the partition wall 38 provided at the substantially central portion of the shaft to the front side, and is spline-coupled to the shaft 42 fixed to the elastic coupling 30 in the bearing unit 40 provided therein. Further, a portion of the propeller shaft 20 rearward of the partition wall 38 is enclosed in a bearing cylinder 44, and the propeller shaft 20 further extends rearward and penetrates the casing 32.
It is screwed to 18 bosses 46. The propeller shaft 20 is rotatably supported by a plurality of bearings at appropriate places and is also sealed with a support portion by an oil seal or the like.

The specific structure of the casing 32 is the water suction port.
Suction casing 35, which constitutes the peripheral wall of 24, suction casing
Impeller duct 37 accommodating impeller 18 following 35,
A vane duct including a vane 28 following the impeller duct 37
39, and an injection duct 41 following the stationary vane duct 39.

The structure of the water suction port 24 is shown in detail in FIGS.
First, on the outer side of the water suction port 24, a lattice 50 that is formed of a plurality of lattice members 48 that extends in the front-rear direction of the water suction port 24 and is spaced from each other so as not to impair the water suction performance is mounted. . This makes it possible to remove wood chips, debris, etc., and to easily remove the entire lattice 50 when the lattice member 48 is damaged. Here, reference numeral 51 is this lattice 50.
Is a bolt for attaching to the suction casing 35 forming the water suction port 24. As shown in FIG. 2, the rear edge portion 52 of the suction casing 35, which is the peripheral wall of the water suction port 24, is formed in an acute angle section in the longitudinal direction of the ship, and the angle of the inner surface thereof allows the water to be smoothly guided to the impeller 18. Is inclined to. This trailing edge 52
A protective cover 54 having a substantially U-shaped cross section in the longitudinal direction of the ship is attached so as to cover the bottom of the trailing edge 52, and in particular, to a portion of the inner surface of the trailing edge 52 from the bottom. And this protective cover
One side of the lattice 50 is inserted between the lattice 50 and the rear edge portion 52, and is fastened together by the bolt 51. The protective cover 54 is preferably made of stainless steel or aluminum, and the inner surface shape of the protective cover 54 is such that the water suction port 24 is inclined more acutely from the horizontal axis.

In this way, since the protective cover 54 is attached so as to cover the rear edge portion 52 of the peripheral wall of the water suction port 24, even if a piece of wood or pebbles enters the water suction port 24 through the lattice 50, Against these, not only the tip of the rear edge portion 52 of the water suction port 24 but also the inside thereof can be protected.

The protective cover 54 may be made of plastic,
In this case, the plastic has a sufficient impact strength and is less likely to be damaged.

Further, even when the protective cover 54 is damaged and needs to be replaced, it is cheaper than the case where the suction casing 35 is replaced.

Next, FIGS. 5 to 6 show a second embodiment of the present invention. This embodiment is an application of the present invention to an outboard water injection propulsion machine.

First, in FIG. 5, the propulsion unit 60 is mainly equipped with an engine (not shown) in the upper cowling 62 and an upper casing 64 is provided below the propulsion unit 60 like the outboard motor. A water injection unit 66 is provided in place of the lower casing of the outboard motor. The water injection unit 66 has a water suction port 68 opening in the water at the bottom thereof, and a jet port 70 communicating with the water suction port 68 for jetting water backward, and by covering the jet port 70. A reverse bucket 72 for obtaining thrust for reverse drive is provided. As with the outboard motor, the stern plate of the hull 12
A clamp bracket 74 is fixed to 73, and a swivel bracket 76 that rotates around a pin 75 is pivotally supported with respect to the clamp bracket 74, and the swivel bracket 76 carries the Abber casing 64.

The structure of the water injection unit 66 is shown in detail in FIG. Reference numeral 78 is an impeller fixed to a drive shaft 79 connected to an engine (not shown), and water is introduced from the water suction port 68 through the lattice 80 by rotation of the impeller 78 via the drive shaft 79, Then, under the thrust of the impeller 78, this water passes through the volute chamber 81 that extends substantially horizontally in a spiral shape, and is jetted rearward from the jet port 70. The casing 82 forming the water suction port 68 has a trailing edge portion 83 formed in an acute-angled cross section in the longitudinal direction of the ship as in the above-described embodiment.
And a protective cover 84 is attached so as to cover the rear edge portion 83. This protective cover 84 is also formed in a substantially U-shaped cross section in the longitudinal direction of the ship, and the rear edge portion 83 is formed together with the lattice 80 by bolts 85.
Have been tightened together.

Reference numeral 86 is a ring, 87 is an oil chamber, and 88 is an oil pouring / discharging hole for supplying and discharging oil to / from the oil chamber 87. A part of the water sucked by the rotation of the impeller 78 is guided to the engine through the water intake 89 and the pipe 90.

In this propulsion unit, the water sucked from the water suction port 68 by the rotation of the impeller 78 is jetted rearward from the jet port 70 to obtain a reaction force for forward movement.
When 72 is rotated upward from the state shown in the figure to a position where the ejection port 70 is closed, the water is changed in direction by the reverse bucket 72 and is ejected forward, whereby a reaction force for reverse travel is obtained. be able to.

Incidentally, the rear edge portion 83 of the casing 82 forming the water suction port 68
Is covered with the protective cover 84 as in the above-mentioned embodiment, so that the trailing edge portion 83 can be protected against foreign matter that enters the inside beyond the lattice 80.

According to the above two embodiments, the inside of the trailing edge portion of the water suction port can be protected as described above, and in particular, the presence of the protective covers 54, 84 prevents the water suction port 24, 68 from being damaged. As a result of the deformation of the structure, a specific effect on the dynamic performance is obtained. That is, by mounting the protective cover,
There is a unique effect that the opening area of the water suction port is reduced, which improves the performance when the throttle valve of the engine is fully opened and can increase the maximum speed.

Also, by removing this protective cover and replacing the lattice 50 with one that matches the water suction port, the opening area of the water suction port becomes larger compared to the state in which the protection cover is attached,
This improves the acceleration performance of the propulsion unit.

Therefore, if the protective cover is attached and detached by the mounting bolt, the power performance can be changed according to the application. Here, for this effect, the protective cover may be one having a lower static strength than the rear edge portion, for example, one formed of plastic or the like.

[Effects] As described above, according to the present invention, the rear edge portion of the water suction port is covered with the protective cover, so that foreign matter that can enter the inside through the grid provided outside the water suction port. On the other hand, there is an excellent effect that the inner wall inside the water suction port can be effectively protected.

[Brief description of drawings]

FIG. 1 is a sectional view showing the whole of a small leisure ship which is an embodiment of a suction port structure of a water injection device according to the present invention, and FIG. 2 is an enlarged sectional view showing a water injection unit in the same embodiment. 3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2, and FIG. 5 is the outboard water which is the second embodiment of the present invention. 6 is a side view showing the entire injector, FIG.
The drawing is a cross-sectional view showing an enlarged main part of the second embodiment. 16, 66 …… Water injection unit 18, 78 …… Impeller 24, 68 …… Water inlet 26, 70 …… Jet outlet 35, 82 …… Casing 48 …… Lattice member 50, 80 …… Lattice 52, 83… … Rear edges 54, 84 …… Protective cover

Claims (1)

[Claims] 1. A water suction port opened in water, a jet port for jetting water to obtain a reaction force, and a water suction port disposed between the water suction port and the jet port. An impeller for sucking and ejecting as a jet from the jet port, at least the rear edge of the peripheral wall forming the water suction port is formed in an acute angle in the longitudinal direction of the ship, and extends in the longitudinal direction of the water suction port. In a water injection propulsion device in which a grid made up of a plurality of grid members spaced apart from each other is arranged outside the water suction port, the ship longitudinal cross-section is substantially cross-sectioned so as to cover the rear edge of the peripheral wall of the water suction port. Suction structure of water jet propulsion device with U-shaped protective cover.