JPH058794A - Small skid boat - Google Patents

Abstract

PURPOSE:To improve in a muffler and to reduce complexity in an engine mounting portion for a small skid boat. CONSTITUTION:In a small skid boat, which comprising a water jet propulsion engine, in the hull thereof, having an engine portion 5 and a nozzle portion 3, and a first 14 and second mufflers 15 installed at the exhaust side of the engine, means 4 for introducing cooling water is disposed from the nozzle portion to the exhaust side of the above engine. Thus, capacity for the mufflers may be secured, thereby improving in the function of the muffler and also using it as a step for boarding. Moreover, complexity in an engine mounting portion in the hull may be reduced and a workable layout may be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small planing boat, and more particularly to a small planing boat provided with a silencer on the outer stern of the hull.

[0002]

2. Description of the Related Art A cross-sectional view of a small planing watercraft in a conventional example is shown in FIG. In FIG. 3, reference numeral 1 indicates the boat body. An engine 5 as a propulsive power source is arranged in the rear part of the boat body 1, and an exhaust manifold 8, a primary silencer 14, a secondary silencer 15, and an exhaust pipe 16 are provided on the exhaust side of the engine 5. The exhaust system is sequentially connected. An intake duct 12 for absorbing water and an impeller housing 1 for generating water jets are provided in a lower portion of the main body adjacent to the engine section.
3, a nozzle 3 for converging water jets is arranged respectively. Further, below the outside of the stern, a deflector 11 is provided for changing the direction of the jet flow by applying a jet flow and moving the boat backward.

Next, the operation of the above conventional example will be described.
In FIG. 3, an impeller (not shown) in the impeller housing 13 is rotationally driven by the engine 5 so that a propelling medium such as seawater 19 is introduced into the intake duct 1.
2 is sucked in, pressurized, converged by the nozzle 3, and discharged as a water jet flow. As a result, the propulsive force of the boat is obtained. Further, the exhaust gas of the engine 5 passes through the exhaust manifold 8, and the primary silencer 1
4, the sound is sequentially silenced through the secondary silencer 15, and is guided to the exhaust pipe 16 and discharged from the exhaust port 16a.

[0004]

However, in the above-mentioned conventional example, it is necessary to house the above-mentioned engine section in a hull having a small size and a limited storage space. As a result, the packing density of parts in the inboard storage part increases,
Work such as removal and connection piping are complicated. Therefore, the layout is such that the workability is difficult, because the hull requires an opening for maintenance and the like.

In addition, because of the space of the onboard storage,
In particular, there is a possibility that the capacity of the silencer, which requires a large volume, cannot be set to a sufficient size. For this reason, there are means such as relocating the silencer from the inside of the hull to the stern outside. However, when the crew member 14 gets into the ship from the seawater 19, he / she rides from the stern, so the engine exhaust causes excessive When the muffler provided is arranged at the stern, there is a problem that the occupant 14 comes into contact with the muffler having a high temperature, and the muffler cannot be relocated to the outside.

[0006]

OBJECT OF THE INVENTION It is an object of the present invention to provide a small planing boat in which the inconvenience of the conventional example is improved, and in particular, the function of the silencer is improved and the complexity of the engine mounting portion is reduced.

[0007]

[Means for Solving the Problems] A waterjet propulsion engine having an engine section and a nozzle section, and a small gliding system having the waterjet propulsion engine in a hull and having a silencer mounted on the exhaust side of the engine. In the boat, the cooling water introducing means is provided from the nozzle portion to the exhaust side of the engine, and the silencer is provided in the stern portion. These are intended to achieve the above-mentioned object.

[0008]

High-pressure water for cooling is introduced from the nozzle through the cooling water introducing means into the exhaust manifold on the engine exhaust side to lower the temperature on the engine exhaust side and reduce noise.

[0009]

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows an overall perspective view of a small planing boat in which this embodiment is implemented. In FIG. 1, reference numeral 1 indicates a small planing boat main body, and reference numeral 2 indicates a silencer arranged at the stern. FIG. 2 shows a sectional view of the hull of this embodiment. Figure 2
In the inside of the hull, an exhaust manifold 8, a primary silencer 9, and a connecting pipe 10 are sequentially connected to the engine exhaust side of an engine 5 as a propulsion power source. Then, the muffler 2 arranged at the stern portion is connected to the connecting pipe 1 through the hull.
It is connected to 0.

On the other hand, an intake duct 12 for absorbing water, an impeller housing 13 for generating water jets, and a nozzle 3 for converging water jets are provided in the lower portion of the main body adjacent to the engine 5. Further, a cooling water introducing port 6 is arranged at a predetermined position on the inner wall surface of the nozzle 3, and the cooling water introducing pipe 4 is connected from the cooling water introducing port 6 to the exhaust manifold 8.

Next, the operation of the above embodiment will be described. In FIG. 2, an impeller (not shown) in the impeller housing 13 is rotationally driven by the engine 5 to draw in a propellant medium such as seawater 19 from the intake duct 12, pressurize it, and install it at the end portion. By being converged by the generated nozzle 3, it is discharged to the outside as a water jet flow. Further, high-pressure water 7 in the nozzle 3 flows in from a cooling water inlet 6 arranged at a predetermined position on the inner wall surface of the nozzle 3, and is introduced into the exhaust manifold 8 in the engine exhaust side A direction by the cooling water inlet pipe 4. Is led.
At this time, the high-pressure water 7 introduced into the exhaust manifold 8 is ejected by a nozzle (not shown) provided in the exhaust manifold 8 in the form of predetermined water particles in the exhaust direction.

High-pressure water 7 jetted into the exhaust manifold 8
Moves to the primary silencer 9 together with the exhaust flow, lowers the temperature around the exhaust side, and reduces noise. For this reason, the spraying of the high-pressure water 7 prevents the heating of the upstream side of the exhaust side, so that the temperature of the downstream side of the exhaust side can be significantly reduced. In addition, the high-pressure water 7 is water 7 at the bottom of the primary silencer 9.
It temporarily stops as a, but due to exhaust pressure, the connecting pipe 10
Via the secondary muffler 2 provided in the stern,
It is discharged to the outside of the ship through the exhaust port 2a together with the exhaust gas.

Here, in the above-mentioned embodiment, the one having the primary silencer 9 and the secondary silencer 2 has been described, but the invention is not limited to this, and the primary silencer 9 may be omitted. .

[0014]

As described above, according to the present invention, the cooling water introducing means is provided from the nozzle portion of the water jet propulsion engine to the exhaust side of the engine, and the silencer is arranged in the stern portion. As a result, heating of the upstream side of the exhaust side of the engine is prevented, so that the temperature of the downstream side of the exhaust side can be significantly reduced. For this reason, the secondary silencer can be relocated to the stern used when an occupant gets onboard from seawater. Therefore, the muffler can be arranged outside the ship which can take a lot of space, so that the capacity of the muffler can be sufficiently secured and the muffling function can be improved. In addition, the silencer provided at the stern is a substantially rectangular parallelepiped, and by adopting a shape that covers the upper portion of the propulsion engine member that has been conventionally equipped,
It can be effectively used as a safe platform for boarding passengers on board. Furthermore, it is possible to reduce the complexity of the onboard engine mounting part, to provide a layout with good workability, and to provide an unprecedented small-sized planing boat that can reuse the vacant space as another application space. can do.

[Brief description of drawings]

FIG. 1 is a perspective view of a small planing boat body showing a first embodiment of the present invention.

FIG. 2 is a sectional view illustrating the embodiment of FIG.

FIG. 3 is a sectional view illustrating a conventional example.

[Explanation of symbols]

1 Small planing boat body as a hull 2 Secondary silencer Nozzle as 3 nozzles 4 Cooling water introduction pipe as cooling water introduction means 5 Engine as an engine section 6 Cooling water inlet as cooling water introducing means 20 Waterjet propulsion organization

Claims (2)

[Claims] Claims: 1. A compact water jet propulsion engine having an engine section and an ejection nozzle section, and a compact body having the water jet propulsion engine in a hull and having a secondary silencer mounted on the exhaust side of the engine section. In the planing boat, a small planing boat characterized in that cooling water introducing means is provided from the jet nozzle part to the exhaust side of the engine part, and the secondary silencer is arranged on the outside of the stern. 2. The small gliding according to claim 1, wherein the secondary silencer is a substantially rectangular parallelepiped, and the upper surface of the secondary silencer is arranged horizontally on the outer side of the stern. Boat.