JP2003261097A - Sound insulating structure for pump chamber of water jet propulsion boat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce exhaust noise. <P>SOLUTION: By providing a first shower duct 30 between an exhaust outlet 6a of the pump chamber 6 and an opening of an injection nozzle 26, and providing a second shower duct 31 in a neighborhood of the exhaust outlet 6a of the pump chamber 6, a curtain like shower of water is jetted from a nozzle 30c of the first shower duct 30 across the pump chamber 6, and at the same time, a curtain like shower of water is jetted from a nozzle 31c of the second shower duct across the exhaust outlet 6a. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound insulation structure for a pump room of a water jet propulsion watercraft.

[0002]

2. Description of the Related Art A water jet propulsion boat has a pump housing of a jet propulsion unit housed in a pump chamber defined at the lower rear part of the hull together with a bottom plate. The water sucked from the suction port to the water suction duct is jetted rearward from the jet nozzle at the rear part of the pump housing, so that the water is propelled forward. Further, by turning the deflector about the vertical axis with the steering wheel, the deflector is turned while being propelled forward.

An exhaust pipe of the engine is connected to the wall forming the pump chamber so that exhaust gas is discharged from the exhaust outlet of the pump chamber to the outside of the boat.

[0004]

In the water jet propulsion watercraft as described above, there is a problem that exhaust noise increases because exhaust gas is directly discharged from the exhaust outlet of the pump chamber to the outside of the watercraft.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sound insulation structure for a pump chamber of a water jet propulsion watercraft that can reduce exhaust noise.

[0006]

In order to solve the above-mentioned problems, according to claim 1 of the present invention, a pump housing for a jet propulsion device is housed in a pump chamber defined with a ship bottom plate at a lower rear portion of a hull. , The rotation of the impeller in the pump housing causes the water sucked from the water suction port at the bottom of the ship to be jetted backward from the jet nozzle at the rear part of the pump housing, and the engine exhaust to the wall forming the pump chamber. In a water jet propulsion watercraft in which a pipe is connected to allow exhaust gas to be discharged from the exhaust outlet of the pump chamber to the outside of the boat, a shower water with a curtain shape is provided between the exhaust outlet of the pump chamber and the injection port of the injection nozzle. To provide a sound insulation structure for a pump room of a water jet propulsion watercraft, characterized in that a shower duct having an ejection port for ejecting water is provided.

According to the first aspect of the present invention, by providing a shower duct between the exhaust outlet of the pump chamber and the injection port of the injection nozzle, curtain-like shower water is ejected from the ejection port of the shower duct across the pump chamber. Therefore, the exhaust noise is shielded by the curtain-shaped shower water, and the exhaust noise leaking from the pump chamber is reduced.

According to a second aspect of the present invention, the pump housing of the jet propulsion machine is housed in a pump chamber defined in the lower rear part of the hull together with the bottom plate, and the water on the bottom of the ship is rotated by the rotation of the impeller in the pump housing. The water sucked from the suction port to the water suction duct is jetted backward from the jet nozzle at the rear part of the pump housing, and the exhaust pipe of the engine is connected to the wall that constitutes the pump chamber, and the exhaust gas is exhausted from the pump chamber. In a water jet propulsion boat adapted to be discharged from the boat to the outside of the boat, a shower duct having a jet port for jetting curtain-shaped shower water is provided in the vicinity of the exhaust port of the pump chamber. The sound insulation structure of the pump room of the propulsion boat is provided.

According to the second aspect of the present invention, by providing the shower duct in the vicinity of the exhaust outlet of the pump chamber, curtain-shaped shower water is jetted from the jet outlet of the shower duct across the exhaust outlet. Exhaust noise is shielded by the shower water, and exhaust noise leaking from the pump room is reduced.

According to a third aspect of the present invention, the pump housing of the jet propulsion device is housed in the pump chamber defined in the lower rear part of the hull together with the bottom plate, and the water at the bottom of the ship is rotated by the rotation of the impeller in the pump housing. The water sucked from the suction port to the water suction duct is jetted backward from the jet nozzle at the rear part of the pump housing, and the exhaust pipe of the engine is connected to the wall that constitutes the pump chamber, and the exhaust gas is exhausted from the pump chamber. In a water jet propulsion boat adapted to be discharged from the water to the outside of the boat, a first shower duct having a jet port for jetting curtain-shaped shower water is provided between the exhaust outlet of the pump chamber and the jet port of the jet nozzle. In addition, a second shower duct having an ejection port for ejecting the curtain-shaped shower water is provided near the exhaust outlet of the pump chamber. It is intended to provide a sound insulation structure of the pump chamber of the watercraft, characterized in that.

According to the third aspect, the first shower duct is provided between the exhaust outlet of the pump chamber and the injection port of the injection nozzle, and the second shower duct is provided in the vicinity of the exhaust outlet of the pump chamber. Curtain-shaped shower water is jetted from the jet outlet of the first shower duct across the pump chamber, and at the same time, curtain-shaped shower water is jetted from the jet outlet of the second shower duct across the exhaust outlet.
The exhaust noise is shielded by the curtain-shaped shower water, and the exhaust noise leaking from the pump chamber is further reduced.

When at least one of the waste water from the engine and the water intake from the jet propulsion machine is supplied to the shower duct as described in claim 4, these water supply facilities can be used rationally.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view of the water jet propulsion boat 1, FIG.
Is a plan view, in which the steering handlebar 3 is provided on the hull 2 of the water jet propulsion boat 1 on the hull centerline slightly in front of the central part, and on the rear side thereof is a seat base 2b extending in the stern direction. A detachable straddle-type seat 4 is provided on the upper surface of the seat base 2b, and foot steps 2a are formed on both sides thereof.

Inside the hull 2, an engine chamber 5 is formed on the front side and a pump chamber 6 is formed on the rear side. Inside the engine chamber 5, below the seat 4 and on the left and right sides of the hull 2. An engine 7 is installed in the center of the direction, and a fuel tank 8 is installed in front of it. In front of the fuel tank 8, an intake duct 20a for introducing the air outside the vessel into the engine compartment 5 inside the vessel is provided. An intake duct 20b for introducing the air outside the ship into the engine compartment 5 inside the ship is also provided behind the engine 7.

The engine 7 is connected from a crank shaft via a coupling and an impeller shaft so as to drive an impeller in a pump housing 9 of a jet propulsion machine 10 housed in the pump chamber 6.

The engine 7 is provided with an intake device located on the starboard side of the crankcase and on the port side of the cylinder block with an exhaust device.

The exhaust pipe constituting the above exhaust device is connected to the exhaust port on the port side of the hull of the cylinder block to extend the exhaust passage to the front of the engine 7.
An exhaust expansion chamber 13 that is connected to the downstream end of the exhaust manifold 12 and bypasses the front upper portion of the engine 7 in a U shape and extends rearward above the starboard side of the engine 7; Behind the engine 7 connected to the rear end,
An exhaust pipe 15 extending obliquely downward and to the left in a hull rear view, a water lock 17 connected to a rear end portion of the exhaust pipe 15 via a flexible rubber hose 16, and the water lock 1
After extending upward from the upper portion of the pump chamber 7, the pump chamber 6 is traversed above the pump chamber 6 and extends downward to the rear on the starboard side, and is connected to a wall forming the pump chamber 6 and a discharge pipe 18 is provided. Then, the exhaust gas passes through the inside of the pump chamber 6 from the exhaust outlet 6a of the wall of the pump chamber 6 (see FIG. 5), and is discharged to the outside of the boat from the rear opening of the pump chamber 6.

As shown in FIG. 5, the pump chamber 6 is formed by denting the rear lower part of the hull 2 upward, and a ship bottom plate 21 is provided at the lower part of the pump chamber 6 and the pump chamber 6 is also provided. At the front end of 6, the rear end of the water suction duct 23 that extends while curving rearward and upward from the water suction port 22 formed in the bottom of the hull 2 is exposed. The end is connected to the front end of a pump housing 9 housed in the pump chamber 6.

An injection nozzle 26 is provided in the rear portion of the pump housing 9, and a deflector 27 which is rotated around the vertical axis by the steering handle 3 is provided on the outer peripheral portion of the injection nozzle 26.

On the other hand, as shown in FIGS. 3 and 4, the exhaust outlet 6a of the pump chamber 6 (see FIG. 5) and the injection nozzle 2 are provided.
At the upper part between the injection port of 6 and the inner surface 6 of the upper wall of the pump chamber 6,
There is provided a first shower duct 30 which is attached over substantially the entire width of b and which has a large number of jet outlets 30c for jetting curtain-shaped shower water (see symbol a) downward at a predetermined small interval. .

As shown in FIGS. 3 and 5, the upper portion of the pump chamber 6 in the vicinity of the exhaust outlet 6a is attached to the inner surface 6b of the upper wall of the pump chamber 6 to form curtain-shaped shower water (symbol b). The second shower duct 31 in which a large number of jet outlets 31c are formed to jet downward at predetermined small intervals.
Is provided.

To each of the shower ducts 30 and 31, a waste water supply port 3 for supplying waste water from the engine 7 is provided.
0a, 31a and at least one of intake water supply ports 30b, 31b for supplying intake water from the jet propulsion device 10 are formed. That is, the first shower duct 30
One of the waste water supply port 30a and the intake water supply port 30b is formed in the
Water may be supplied from the Similarly, in the second shower duct 31, one of the waste water supply port 31a and the intake water supply port 31b is formed, and the formed supply port 31a (or 31
Water may be supplied from b).

When the sound insulation structure of the pump chamber 6 of the water jet propulsion boat 1 is constructed as described above, the exhaust outlet 6 of the pump chamber 6 is formed.
By providing the first shower duct 30 in the upper part between a and the injection port of the injection nozzle 26, curtain-shaped shower water (see symbol a) is passed from the ejection port 30c of the first shower duct 30 across the pump chamber 6. Is exhausted downward, the exhaust noise is shielded by the curtain-shaped shower water, and the exhaust noise leaking from the pump chamber 6 is reduced.

At the same time, by providing the second shower duct 31 in the upper part of the pump chamber 6 near the exhaust outlet 6a,
Curtain-shaped shower water (see reference numeral b) from the jet outlet 31c of the second shower duct 31 across the exhaust outlet 6a.
Is exhausted downward, the exhaust noise is shielded by the curtain-shaped shower water, and the exhaust noise leaking from the pump chamber 6 is reduced.

Thus, the exhaust noise is shielded by the curtain-shaped shower water in the first shower duct 30 and the second shower duct 31, respectively, and the exhaust noise leaking from the pump chamber 6 is further reduced. Note that the exhaust noise is further reduced by providing both the first shower duct 30 and the second shower duct 31, but the exhaust noise is reduced even if only one of them is provided.

Further, in the curtain-shaped shower water, as compared with a sound insulating plate made of rubber or the like, even if the jet propulsion machine 10 has many complicated irregularities, a gap is less likely to occur, so that the leakage of exhaust noise is reduced.

Furthermore, each of the shower ducts 30 and 31 described above
Moreover, since at least one of the waste water from the engine 7 and the water intake from the jet propulsion machine 10 is supplied, these water supply facilities can be reasonably utilized and there is no need to separately install the water supply facilities. The cost will be lower. in this way,
If the waste water from the engine 7 and the water intake from the jet propulsion machine 10 are used, there is no problem even if the amount of water supplied is small because the exhaust noise is low during low-speed cruising at a low engine speed. When traveling at high speeds, the exhaust noise is high, but the amount of water supplied is large, so that the exhaust noise can be effectively reduced according to the running condition.

The jet outlets 30c and 31c of the first shower duct 30 and the second shower duct 31 may be holes or slits.

[0030]

As is apparent from the above description, according to claim 1 of the present invention, by providing a shower duct between the exhaust outlet of the pump chamber and the injection port of the injection nozzle, the injection of the shower duct is performed. Since curtain-shaped shower water is jetted from the outlet across the pump chamber, the curtain-shaped shower water blocks exhaust noise and reduces exhaust noise leaking from the pump chamber.

According to the second aspect of the present invention, by providing a shower duct in the vicinity of the exhaust outlet of the pump chamber, curtain-shaped shower water is jetted from the jet outlet of the shower duct across the exhaust outlet. The exhaust noise is shielded by the shower water, and the exhaust noise leaking from the pump chamber is reduced.

According to the third aspect of the present invention, the first shower duct is provided between the exhaust outlet of the pump chamber and the injection port of the injection nozzle, and the second shower duct is provided in the vicinity of the exhaust outlet of the pump chamber. Since the curtain-shaped shower water is jetted from the jet port of the first shower duct across the pump chamber, the curtain-shaped shower water is jetted from the jet port of the second shower duct across the exhaust port at the same time. The exhaust noise is shielded by the curtain-shaped shower water, and the exhaust noise leaking from the pump chamber is further reduced.

When at least one of the waste water from the engine and the intake water from the jet propulsion machine is supplied to the shower duct as described in claim 4, these water supply facilities can be used rationally.

[Brief description of drawings]

FIG. 1 is a side view of a water jet propulsion boat.

FIG. 2 is a plan view of a water jet propulsion boat.

FIG. 3 is a plan view of a pump chamber.

FIG. 4 is a view on arrow X in FIG.

5 is a cross-sectional view taken along the line YY of FIG.

[Explanation of symbols]

1 water jet propulsion boat 2 hulls 6 pump room 6a Exhaust outlet 7 engine 9 Pump housing 18 discharge pipe 21 Ship bottom plate 22 Water suction port 23 Water suction duct 26 injection nozzles 30 First shower duct 30a Waste water supply port 30b Water intake 30c spout 31 First Shower Duct 31a Waste water supply port 31b Water intake supply port 31c spout

Claims (4)

[Claims] 1. A pump housing for a jet propulsion device is housed in a pump chamber defined in the lower rear portion of the hull together with a ship bottom plate, and rotation of an impeller in the pump housing,
The water sucked into the water suction duct from the water suction port at the bottom of the ship is jetted rearward from the jet nozzle at the rear part of the pump housing, and the exhaust pipe of the engine is connected to the wall forming the pump chamber to discharge the exhaust gas to the pump chamber. In a water jet propulsion boat adapted to be discharged from the exhaust outlet of the above, a shower duct having a jet port for jetting curtain-shaped shower water is provided between the exhaust outlet of the pump chamber and the jet port of the jet nozzle. The sound insulation structure of the pump room of the water jet propulsion boat. 2. A pump housing for a jet propulsion device is housed in a pump chamber defined in the lower rear portion of the hull together with a ship bottom plate, and rotation of an impeller in the pump housing,
The water sucked into the water suction duct from the water suction port at the bottom of the ship is jetted rearward from the jet nozzle at the rear part of the pump housing, and the exhaust pipe of the engine is connected to the wall forming the pump chamber to discharge the exhaust gas to the pump chamber. In the water jet propulsion boat configured to discharge the water from the exhaust outlet of the above, a shower duct having an ejection port for ejecting curtain-shaped shower water is provided near the exhaust outlet of the pump chamber. A sound insulation structure for the pump room of a water jet propulsion boat. 3. A pump housing for a jet propulsion device is housed in a pump chamber defined in the lower rear part of the hull together with a ship bottom plate, and rotation of an impeller in the pump housing
The water sucked into the water suction duct from the water suction port at the bottom of the ship is jetted rearward from the jet nozzle at the rear part of the pump housing, and the exhaust pipe of the engine is connected to the wall forming the pump chamber to discharge the exhaust gas to the pump chamber. In a water jet propulsion boat configured to be discharged to the outside from the exhaust outlet of the first shower duct having a jet port for jetting curtain-shaped shower water between the exhaust outlet of the pump chamber and the jet port of the jet nozzle. And a second shower duct having an ejection port for ejecting curtain-shaped shower water is provided in the vicinity of the exhaust outlet of the pump chamber. Sound insulation structure. 4. The sound insulation structure for a pump room of a water jet propulsion boat according to claim 1, wherein at least one of waste water from the engine and intake water from the jet propulsion device is supplied to the shower duct. .