JP2000053089A - Small ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispose a propeller shaft and an exhaust pipe in low positions, to reduce the gravity center of a ship body and to reduce the size of the ship body in a height direction. SOLUTION: In a small ship propelled by transmitting the motive force of an engine 2 to a water jet propeller disposed in the rear end part of a propeller shaft disposed in the longitudinal direction of a sip body and jetting water in a rear direction, the output shaft 2a of the engine 2 is disposed by being made eccentric to one side of the engine 2 in parallel with the propeller shaft, the propeller shaft is connected to the output shaft 2a of the engine 2 via transmission mechanisms 2k, 2i and 2m, and an exhaust pipe 6 provided so as to be extended from the engine 2 toward the rear side of the ship body is disposed in a side opposite the propeller shaft sandwiching the engine 2.

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), and are disclosed. As shown, the propulsion shaft is arranged coaxially with the output shaft of the engine. By the way, if a transmission mechanism is interposed between the propulsion shaft and the engine output shaft, the propulsion shaft and the engine output shaft will be parallel. In this case, if the exhaust pipe is arranged on the same side as the propulsion shaft, The exhaust pipe and the exhaust pipe must be spaced apart from each other in the height direction, and both of them must be arranged. Therefore, the height of the hull may increase, and the center of gravity of the hull may increase.

The present invention has been made to solve the above problems, and an object thereof is to eccentrically move a propulsion shaft with respect to an engine output shaft in a lateral direction (width direction, left and right direction) of a hull. The arrangement relationship between the exhaust pipe and the propulsion shaft, which extend from the engine to the rear of the hull, can be rationally arranged in space, reducing the height of the hull and lowering the center of gravity of the hull. To provide a small boat.

[0005]

According to a first aspect of the present invention, there is provided a water jet propulsion device disposed at a rear end of a propulsion shaft disposed in a longitudinal direction of a hull. In a small boat propelled by injecting water backward, the output shaft of the engine is disposed eccentrically to one side of the engine in parallel with the propulsion shaft, and the propulsion shaft is connected to the output shaft of the engine via a transmission mechanism. In addition, an exhaust pipe provided to extend rearward from the engine to the hull is disposed on the opposite side of the engine from the propulsion shaft.

According to the first aspect of the present invention, in the small boat, the propulsion shaft and the exhaust pipe are arranged on opposite sides of the engine, so that each of the propulsion shaft and the exhaust pipe can be arranged at a low position. Can be lowered, and the size of the hull in the height direction can be reduced.

[0007]

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 for 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 into the engine 2 from the fuel tank 3 shown in FIG. 1 via a fuel supply device and burns in the cylinder, whereby the piston 2f is moved forward and backward, and the piston 2f is moved forward and backward by the crank. The output shaft 2a of the engine 2 is rotated instead of rotating the shaft 2g. This allows
The propulsion shaft 5 is connected via a transmission mechanism to a propulsion shaft 5 disposed adjacent to and parallel to the output shaft 2a and opposite to the engine 2, and the propulsion shaft 5 is rotated. The transmission mechanism will be described later. 1 and 3, the propulsion shaft 5 is disposed on the bottom 1a of the hull 1 at an intermediate portion in the width direction, and is disposed so as to extend in the longitudinal direction (the front-rear direction) of the hull 1. , The propulsion shaft 5
It is connected to the output shaft 2a of the engine 2 via a transmission mechanism.

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 is 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 2 b 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 the cooling flow together, and thus the exhaust gas of the engine 2 and the cooling water after the 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, in a small boat equipped with the above-described propulsion mechanism, the engine 2 is disposed in the hull 1 near the bow in the present embodiment.
Used a two-cycle engine in the embodiment.

FIG. 3 is a sectional view taken along the line AA of FIG. 1 and shows the arrangement of the engine. The engine 2 is a two-stroke engine.
From the center to the port L side (the port L side in the figure, but it may be on the starboard R side in some cases), the cylinder head 2c is set upward, and the cylinder axis 2e is substantially vertical. The engine 2 is eccentrically disposed on the port L side with respect to the propulsion shaft 5 disposed along the hull axis along the center of the hull 1 shown in FIG. 1, and has a cylinder head 2c, a cylinder 2d below the cylinder head 2c,
The engine 2 is provided such that an output shaft 2a driven by a crankshaft 2g is parallel to the propulsion shaft 5 and a lower power supply is provided between the output shaft 2a and the propulsion shaft 5 of the engine 2. Gear transmission mechanism 2 constituting transmission mechanism
The structure was connected via i.

More specifically, as shown in the figure, a drive gear 2k provided on the output shaft 2a and a crankcase 2j of the engine thereof are provided on an intermediate shaft on a parallel shaft eccentrically disposed on the opposite side of the hull. And a driven gear 2m provided on a propulsion shaft 5 disposed parallel to the output shaft 2a and eccentrically opposite to the engine 2 with respect to the intermediate gear 2i.
And mesh with. As a result, the propulsion shaft 5 arranged parallel to the output shaft 2a and arranged eccentrically on the side opposite to the engine 2 in the hull 1 is driven. Note that 2n,
2p is the upper and lower cases of the transmission mechanism.

As clearly shown in FIG. 3, the above-described exhaust system 6, ie, the front exhaust pipe 6a, the silencer 6b, and the rear exhaust pipe 6
As described above, c extends rearward through the side on the port L side of the engine 2 and is connected to the pump housing 4. The exhaust system 6 is connected to the propulsion shaft 5 with the engine 2 interposed therebetween. It will be located on the opposite side. Therefore, the propulsion shaft 5 is disposed so as to extend rearward at the center along the axis of the hull. However, when viewed from the exhaust system 6, the propulsion shaft 5 is disposed at the starboard Rr side in the center of the hull. Become. Therefore, the propulsion shaft 5
The exhaust system 6 having a height and a silencer is distributed on both sides of the engine 2 and does not overlap vertically, so that the size of the hull in the height direction is suppressed, and Both the exhaust system 6 and the propulsion shaft 5 can be arranged at a low position on the hull, and the center of gravity of the hull can be lowered.

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. In the internal space between the inner surface L and the propulsion shaft 5, it is housed on the opposite side and the bow is tapered, so that the axis of the silencer 6b is obliquely arranged in a plan view so as to point in the center direction of the hull. ing. A front exhaust pipe 6a connected to the silencer 6b and a rear exhaust pipe 6b extending rearward and connected to the pump housing 4.
Is disposed on the port L side opposite to the propulsion shaft 5 in the hull 1.

As shown in FIGS. 1 and 3, the small boat provided with the above-mentioned propulsion mechanism has an engine 2 near the bow (front) and a silencer 6b in the exhaust system 6 which are 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,
6c is also disposed on the port L side of the engine 2, and the propulsion shaft 5 is disposed on the starboard Rr side, so that the engine 2 and the exhaust system 7 are not disposed on the front starboard Rr side inside the hull. A space S is formed. As shown in FIGS. 6 and 7, this space S 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, the steering shaft 13a is covered with a steering post 13b on the front starboard side Rr side of the hull 1 adjacent to the engine room 12.
A steering grip 13c (handle) is provided at an end of the steering shaft 13a protruding from a rear end of the steering shaft 3b.
The steering device 13 is configured. 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. Therefore, 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. On the port L side of deck 10, shallow leg space 1 for passengers
6, and a passenger seat 17 on which a passenger sits is provided behind the passenger seat. The cockpit 14 is on the starboard Rr side, and the passenger seat 17 is on the port Lr.
On the side, arranged in the width direction left and right of the hull, and back and forth,
The staggered arrangement prevents the driver and passenger from touching each other.

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.

In the above 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.

[0026]

According to the present invention, the following effects are exhibited by the above configuration. According to a first aspect of the present invention, there is provided a small boat which transmits power of an engine to a water jet propulsion device disposed at a rear end of a propulsion shaft disposed in a longitudinal direction of a hull and injects water backward to propell the water. The engine is disposed eccentrically on one side of the engine in parallel with the propulsion shaft, and the propulsion shaft is connected to the output shaft of the engine via a transmission mechanism, and an exhaust pipe provided to extend rearward from the engine to the hull, Is disposed on the opposite side of the propulsion shaft.

According to the first aspect of the present invention, in the small boat, the propulsion shaft and the exhaust pipe are arranged on opposite sides of the engine, so that the propulsion shaft and the exhaust pipe do not overlap each other.
Thus, the propulsion shaft and the exhaust pipe can be individually arranged and arranged at a low position on the hull. Therefore, the center of gravity of the hull can be lowered, and the size of the hull in the height direction can be reduced.

[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, 2a ... output shaft, 2k,
2i, 2m: power transmission mechanism, 5: propulsion shaft, 6: exhaust system (6a, 6c exhaust pipe, 6b silencer), 4, 7 ... pump housing and impeller constituting a water jet propulsion device.

Claims (1)

[Claims] 1. A small boat which transmits power of an engine to a water jet propulsion device disposed at a rear end of a propulsion shaft disposed in a longitudinal direction of a hull and injects water backward to propell, wherein: The output shaft is arranged eccentrically to one side of the engine in parallel with the propulsion shaft, and the propulsion shaft is connected to the output shaft of the engine via a transmission mechanism, and an exhaust pipe provided to extend rearward from the engine to the hull, A small boat characterized by being disposed on the opposite side of a propulsion shaft with an engine interposed therebetween.