JP2002137794A - Small boat - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the height of the exhaust system together with the engine, making it easier to arrange the exhaust system at a low position while miniaturizing the height direction and lowering the center of gravity in a small ship, I want to be able to reduce the overall height of the power unit. A small boat (1) having an exhaust pipe (6a) connected to an engine (2) from below a slanted cylinder block (2d) and a cylinder head (2c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet propulsion type small boat suitable for leisure use and the like.

[0002]

2. Description of the Related Art As a small boat for leisure propulsion by a water jet propulsion mechanism, U.S. Pat.
No. 6,724 and U.S. Pat. No. 3,623,447 are disclosed. In these small boats, a propulsion shaft is driven by an engine disposed inside the hull, the impeller in the pump housing is rotated by the propulsion shaft, and a jet jet is jetted backward to obtain a propulsion force. . These small boats, all of which have an engine covered with a cover, are arranged upright at the center of the hull in the width direction (lateral direction, left and right direction).

[0003]

The above-mentioned conventional small boats are all arranged upright at the center of the hull in the width direction (lateral direction, left and right direction). When a four-stroke engine having a structure in which mechanisms and the like are arranged on a cylinder head is mounted, the height of the engine is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to make it possible to mount a four-stroke engine on a small boat and reduce the height of the engine. The size of the small boat in the height direction can be reduced, the center of gravity of the small boat can be placed at a low position to reduce the center of gravity, and the exhaust system can be easily placed at a low position. It is an object of the present invention to provide a small boat in which the height of the power unit can be reduced and the height of the entire power unit can be reduced.

[0005]

In order to solve the above problems, an engine room 12 is provided in which the upper surface of a hull 1 having a substantially V-shaped cross section is covered with a deck 10. The four-cycle engine 2 is housed and installed on the bottom 1a of the hull, and the power of the four-cycle engine 2 is
A small boat that transmits water to a water jet propulsion device disposed at the rear end of a propulsion shaft 5 disposed in the longitudinal direction of the hull, injects water backward, and propells the watercraft.
The cycle engine 2 includes a crankcase 2j disposed on a ship bottom 1a, a cylinder block 2d on the crankcase 2j, and a cylinder head 2c having a valve mechanism on the cylinder block 2d.
Is arranged so that the cylinder head 2c is located upward toward one side of the hull, and the crankcase 2j is disposed substantially at the center on the ship bottom 1a.
The cylinder axis 2e is arranged to be inclined from the bottom 1a in the direction of one side L of the hull 1 and an exhaust pipe 6a is connected to the engine 2 from below the inclined cylinder block 2d and cylinder head 2c. I do.

According to a second aspect, in the first aspect, the inclination angle θ1 of the cylinder axis 2e with respect to the horizontal plane is made larger than the inclination angle θ of the ship bottom 1a located below the inclined cylinder block 2d and the cylinder head 2c with respect to the horizontal plane. It is characterized by the following.

According to the first aspect, in a small boat, a four-cycle engine 2 serving as a propulsion power source is provided with a crankcase 2j disposed on a bottom 1a, a cylinder block 2d on the crankcase 2j, and a valve mechanism on the cylinder block 2d. And the cylinder axis 2e of the four-stroke engine 2 is arranged such that the cylinder head 2c is located upward toward one of the shore sides L of the hull 1 and the crankcase 2j is 1a, located near the center of the ship 1 on one side (width direction, left / right direction)
, The overall height of the engine 2 including the cylinder head 2c including the valve mechanism can be reduced, the center of gravity of the hull 1 can be lowered, and the center of gravity of a small boat can be reduced. The exhaust system 6 can be easily arranged at a low position, so that the height of the exhaust system 2 as well as the engine 2 can be reduced, and the overall height of the power unit of the small boat can be reduced.

In the second aspect, the inclination angle θ1 of the cylinder axis 2e with respect to the horizontal plane is larger than the inclination angle θ of the cylinder bottom 2a with respect to the horizontal plane below the inclined cylinder block 2d and the cylinder head 2c. The arrangement space can be increased.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a schematic plan view of the interior of a small boat according to the present invention, FIG. 2 is a central longitudinal side view of the small boat shown in FIG.
3 is a cross-sectional view taken along line AA of FIG. 1, FIG. 4 is a cross-sectional view taken along line BB of FIG. 1, FIG. 5 is a perspective view of an external appearance showing an embodiment of the small boat according to the present invention, and FIG. 5 is a plan view of FIG. In the following drawings, F indicates forward, Rr indicates backward, L indicates port, and R indicates starboard.

As shown in FIGS. 1 and 2, the propulsion mechanism of a small boat includes an engine 2, a fuel tank 3, a pump housing 4, a propulsion shaft 5, and an exhaust system 6 disposed inside a hull 1. It is configured. The propulsion mechanism is a water jet propulsion mechanism, and propells the hull 1 as follows.

Fuel is supplied from the fuel tank 3 into the engine 2 via a fuel supply device, and is burned in a cylinder.
As a result, the piston 2f (see FIG. 3) is moved forward and backward, and the forward and backward movement of the piston 2f is changed to the rotational movement of the crankshaft 2g to rotate the output shaft 2a of the engine 2. This allows
The propulsion shaft 5 connected to the output shaft 2a is rotated. Propulsion axis 5
As shown in FIGS. 1 and 3, on the bottom 1a (ship bottom) of the hull 1 is disposed at an intermediate portion in the width direction, and is disposed so as to extend in the longitudinal direction (front-rear direction) of the hull 1. The propulsion shaft 5 is connected to the output shaft 2a of the engine 2.

Therefore, by connecting the propulsion shaft 5 coaxially immediately after the output shaft 2a, the engine output system does not require a reduction gear or a transmission mechanism, and the power transmission system between the engine 2 and the propulsion shaft 5 is not required. The structure is simplified by using only the joints. Therefore, the output system of the engine 2 does not need a speed reduction mechanism or a complicated power transmission mechanism, and the structure can be used as it is, and the center of gravity can be reduced.

An impeller 7 is connected to the rear end of the propulsion shaft 5, and the impeller 7 is driven to rotate in the pump housing 4, and the water inlet 4 opened at the bottom of the hull of the pump housing 4.
a, seawater or the like is sucked into the pump housing 4 and jetted out from a nozzle 4b provided at the rear end (stern) of the pump housing 4 as a water jet jet, thereby propelling the hull 1.

The exhaust system 6 includes an exhaust port 2b of the engine 2.
And an upstream exhaust pipe 6a, a silencer 6b, and a downstream exhaust pipe 6c arranged on one side of the engine 2 for connecting an opening 4c provided separately from the water inlet 4a of the pump housing 4 described above. . The exhaust system 6 discharges the engine and discharges the cooling water after cooling the engine as follows.

The muffler 6b has a structure in which the exhaust gas of the engine 2 and the cooling water after cooling flow together, and thus the exhaust gas of the engine 2 and the cooling water after cooling flow into the muffler 6b together. Then, the pressure inside the silencer 6b increases, and the exhaust and cooling water inside the silencer 6b are pushed out toward the opening 4c of the pump housing 4 by this pressure,
The exhaust of the engine 2 and the cooling water after cooling are simultaneously discharged. At the same time, the cooling water in the silencer 6b causes the engine 2
Exhaust sound is absorbed, and the exhaust sound is silenced.

As shown in FIGS. 1 and 2, a small boat equipped with the above-described propulsion mechanism has an engine 2 disposed near a bow in a hull 1 in this embodiment.
Used a four-cycle engine in the embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. As shown in FIG. 3, the cylinder head 2c is disposed on the upper left side of the hull 1a in the hull 1 so as to be located upward toward the port side. The crankcase 2j is located approximately at the center of the bottom 1a.
The upper cylinder block 2d is arranged so that the upper part is directed to the port L and substantially directed to the center on the ship bottom 1a. As is clear from FIG. 3, the hull 1 has a substantially V-shaped cross section at the bottom of the bottom 1a.

Therefore, the cylinder axis 2e of the engine 2
Are arranged so that the left side is upward and the right side is downward so that the port L side faces upward. Therefore, the entire engine 2 is arranged on the port L side so that the cylinder head is directed obliquely upward in the port L direction from the center on the ship bottom 1a inside the hull 1, whereby the engine 2 arranged on the port L side Is arranged so as to slant obliquely to the port L side, that is, the cylinder block 2d of the engine 2 is arranged to be inclined in the lateral direction (width direction) of the hull.
The height of the four-stroke engine 2 including the cylinder head 2c having the valve operating mechanism in the cylinder head 2c can be reduced. Engine 2 has 4 mounts 2h
(... denotes a plurality, the same applies hereinafter) and is fixed and supported on the ship bottom 1a.

The upstream exhaust pipe 6a of the exhaust system 6 is connected to the engine from below the cylinder block 2d and the cylinder head 2c as clearly shown in FIG. Therefore,
It is easy to arrange the exhaust system 6 at a low position as shown in FIG. 3, and as can be understood from FIG. 3, the height of the exhaust system as well as the engine can be reduced, and the overall height of the power unit of the small boat can be reduced. it can.

As clearly shown in FIG. 3, the inclination angle θ1 of the cylinder axis 2e with respect to the horizontal plane is set larger than the inclination angle θ of the ship bottom 1a located below the inclined cylinder block 2d and the cylinder head 2c with respect to the horizontal plane. ing. Therefore, as can be understood from FIG. 3, the arrangement space of the exhaust system can be increased.

As further shown in FIG. 3 and as will be described later, a leg space is concavely formed on the side of the cylinder head 2c of the engine 2 so as to be divided from the engine room 12 so as to dive downward from the deck surface of the deck 10. 15 are provided. As a result, the leg space can be secured by utilizing the dead space on the side of the engine as can be understood from FIG.

As shown in FIG. 1, the fuel tank 3 is disposed near the center of gravity 1g at the center in the width direction at the center in the front-rear direction on the bottom 1a of the hull. As shown in FIG.
On the bottom 1a of the fuel tank 3, a recess 3a through which a propulsion shaft 5 arranged from the front engine 2 side to the rear pump housing 4 (see the plan view in FIG. The propulsion shaft 5 extends in the front-rear direction so as to dive from above, and as shown in FIGS. The fuel tank 3 is fixed on the bottom 1a of the hull 1 via support members 8,8.

As shown in FIGS. 1 and 2, the propulsion shaft 5 has a bearing 9a provided in the recess 3a of the fuel tank 3.
And a bearing 9b provided on the bottom 1a in front of the pump housing 4 behind the fuel tank 3 and a bearing 9c provided inside the pump housing 4 so as to be freely rotatable. The bearings 9a, 9b, 9c use ball bearings or the like to smooth the rotation of the propulsion shaft 5. still,
The propulsion shaft 5 is provided with a bearing 9a from the viewpoint of assembly and vibration isolation.
And 9b, and the opposing divided ends are detachably connected to each other by a coupling 9d.

As shown in FIG. 1, a silencer 6b having a large volume, a large capacity, and an outer shape in the exhaust system 6 includes a left side surface of the engine 2 disposed at a front portion in the hull 1 and a port side of the hull 1. Since it is housed in the internal space between the inner side of the L and the bow is tapered, the axis of the silencer 6b is obliquely arranged in a plan view so as to point toward the center of the hull. A front exhaust pipe 6a connected to the silencer 6b and a rear exhaust pipe 6c extending rearward and connected to the pump housing 4 are arranged in the hull 1 on the port L side.

As shown in FIGS. 1 and 3, the small boat equipped with the above-mentioned propulsion mechanism has a structure in which the muffler 6b in the engine 2 and the exhaust system 6 near the bow (front) is arranged in the width direction inside the hull 1. It is located on the port L side from the center, and the exhaust pipes 6a,
Similarly, 6c is arranged on the port L side, so that a space S where the engine 2 and the exhaust system 7 are not arranged is formed on the front starboard Rr side inside the hull. This space S
However, as shown in FIGS. 6 and 7, it is used as an arrangement portion of the steering device 13, a cockpit 14, and a space under the operator's feet.

FIG. 5 is a perspective view showing the appearance of a small boat according to the present invention. An upper part of the hull 1 is covered with a deck 10, and an engine room 12 is formed below the front port L of the deck 10, which is covered with an engine cover 11 so as to be freely opened and closed.
The engine 2 described above is housed inside.

As shown in FIGS. 2 and 7, a steering shaft 13a is covered with a steering post 13b on the front starboard side Rr of the hull 1 adjacent to the engine room 12.
An end of a steering shaft 13a protruding from a rear end of the steering post 13b has a steering grip 13c.
(The steering wheel) is provided to configure the steering device 13. Therefore, the steering device 13 is disposed at the front of the deck 10 on the starboard Rr side so as to be inclined rearward and upward as shown in FIG.

A cockpit 14 on which a driver sits is provided on the starboard Rr side behind the steering device 13 described above. A pilot's leg space 15 is provided in front of the cockpit 14 adjacent to the engine room 12. Accordingly, the legs of the operator in the cockpit 14 are located in the space S provided below and adjacent to the engine room 12 and opened downward.
2 and is provided in a concave shape so as to dive downward (see FIG. 3 described above). On the port L side of the deck 10, a passenger's shallow leg space 16 and a passenger seat 17 on which the passenger sits behind are provided. The cockpit 14 is on the starboard Rr side, and the passenger seat 17 is on the port side. On the L side, the staggered arrangement is arranged so that the shoulders of the pilot and the passenger do not touch each other, and are arranged on the left and right and in the width direction of the hull.

FIG. 6 is a plan view of FIG.
As shown in FIG. 2, a throttle lever 13d is provided on the right side of the storing grip 13c, and as shown in FIG.
The steering shaft 13a and the steering post 13b
These are configured to be vertically rotatable about a tilt pin 13e provided at the distal end thereof. By moving the steering post 13b including the steering shaft 13a upward, the operator can easily board the boat, and by moving the steering post 13b downward after boarding, the maneuverability is improved. The transom behind the cockpit 14 and the passenger seat 17 is open, improving the boarding of the pilot and passengers.

An inverted concave side guard 19 is provided at the boundary between the driver seat 14 and the passenger seat 17, and a similar side guard 20 is provided at the port L side of the passenger seat 17. . The flanges 18 provided on both the left and right sides of the hull 1 and the deck 10 are wide on the bow side, and the wide flanges 18 provide a wave return, thereby improving wave breaking.

As described above, in the embodiment, the two-seater small boat with the staggered arrangement in which the pilot's leg space is formed on the front starboard side of the hull Rr has been described.
It is also possible to arrange the exhaust system 6 on the starboard side of the hull, and to arrange the pilot's leg space on the port side of the hull. Also, the present invention can be applied to a single-seater small boat having only a cockpit and not having a passenger seat.

[0032]

According to the present invention, the following effects are exhibited by the above configuration. Claim 1 provides an engine room 12 in which the upper surface of a hull 1 having a substantially V-shaped cross section is covered with a deck 10, and in the engine room 12, a four-cycle engine 2 is housed and installed on a hull bottom 1 a of the hull, The power of the 4-cycle engine 2
A small boat, which transmits the water to a water jet propulsion device disposed at the rear end of a propulsion shaft 5 disposed in the longitudinal direction of the hull and injects water backward to propell, is installed on the bottom 1a of the boat.
The cycle engine 2 includes a crankcase 2j disposed on a ship bottom 1a, a cylinder block 2d on the crankcase 2j, and a cylinder head 2c having a valve train on the cylinder block 2d. The four-cycle engine 2 has a cylinder head 2c. It is disposed so as to be located upward toward one side of the hull, the crankcase 2j is disposed substantially at the center on the bottom 1a, and the cylinder axis 2e of the four-stroke engine 2 is moved from the bottom 1a to one side L of the hull 1. The exhaust pipe 6a was connected to the engine 2 from below the inclined cylinder block 2d and cylinder head 2c.

According to the first aspect, in a small boat, the four-stroke engine 2 serving as a propulsion power source is provided with a cylinder head 2c
Is disposed so as to be located upward toward one side L of the hull 1, the crankcase 2j is disposed substantially at the center on the bottom 1a, and the cylinder axis 2e of the four-stroke engine is moved from the bottom 1a to one side of the hull 1. The four-stroke engine 2 composed of the cylinder head 2c including the valve operating mechanism provided on the cylinder head 2c, the cylinder block 2d, and the crankcase 2j is inclined by the cylinder axis 2e. The overall height can be reduced, the center of gravity of the hull 1 can be lowered, the center of gravity of the small boat can be reduced, and the size of the small boat equipped with the four-cycle engine in the height direction can be kept low. In particular, in the present invention, the inclined cylinder block 2d, the cylinder head 2
c, the exhaust pipe 6a was connected to the engine 2 from below.
The exhaust system 6 can be easily arranged at a low position, so that not only the engine 2 but also the exhaust system 6 can be reduced in height, and the overall height of the power unit of the small boat including the engine and the exhaust system can be reduced.

According to a second aspect, in the first aspect, the inclination angle of the cylinder axis 2e with respect to the horizontal plane is larger than the inclination angle of the ship bottom 1a located below the inclined cylinder block 2d and the cylinder head 2c with respect to the horizontal plane. In the second aspect, in addition to the effect of the first aspect, the cylinder axis 2 is larger than the inclination angle θ of the ship bottom 1a located below the inclined cylinder block 2d and the cylinder head 2c with respect to the horizontal plane.
Since the inclination angle θ1 of e with respect to the horizontal plane increases, the space for disposing the exhaust system 6 can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of the interior of a small boat according to the present invention.

FIG. 2 is a central longitudinal side view of a small boat.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is a perspective view of the appearance showing an embodiment of the small boat according to the present invention.

FIG. 6 is a plan view of FIG. 5;

[Explanation of symbols]

1 ... hull, 2 ... engine, 2c ... cylinder head,
2d: cylinder block, 2e: inclined axis of the engine, 5: propulsion shaft, 4, 7 ... pump housing and impeller constituting a water jet propulsion device,
6a: exhaust pipe, 15: leg space, θ: inclination angle with respect to horizontal plane of ship bottom, θ1: inclination angle of cylinder axis with respect to horizontal plane.

Claims (2)

[Claims] 1. An engine room 12 is provided by covering the upper surface of a hull 1 having a substantially V-shaped cross section with a deck 10. A four-stroke engine 2 is housed and installed in the engine room 12 on a bottom 1a of the hull. , The power of the four-cycle engine 2
In a small boat that transmits water to a water jet propulsion device disposed at the rear end of a propulsion shaft 5 disposed in the longitudinal direction of the hull and injects water backward, the four-stroke engine 2 installed on the bottom 1 a A four-stroke engine 2 comprising a cylinder case 2j disposed on a ship bottom 1a, a cylinder block 2d on the crankcase 2j, and a cylinder head 2c provided with a valve mechanism on the cylinder block 2d.
Is disposed so as to be located upward toward one side of the hull, the crankcase 2j is disposed substantially at the center on the bottom 1a, and the cylinder axis 2e of the four-cycle engine 2 is moved from the bottom 1a to one side of the hull 1. The cylinder block 2d and the cylinder head 2 which are arranged to be inclined in the
(c) an exhaust pipe (6a) connected to the engine (2) from below. 2. The inclination angle θ1 of the cylinder axis 2e with respect to the horizontal plane is larger than the inclination angle θ of the ship bottom 1a below the inclined cylinder block 2d and the cylinder head 2c with respect to the horizontal plane. Small boat described in.