JP2837539B2 - Small boat - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a small boat which is a small watercraft called a personal watercraft, and more specifically, a change in the amount of fuel in a fuel tank indicates the weight of the boat. The present invention relates to a small boat capable of reducing the effect on balance and increasing the capacity of a fuel tank.

(Prior Art) In general, small boats are equipped with an engine at the front of the hull and a propulsion unit such as a water jet pump at the rear of the hull, and transmit power between the engine and the propulsion unit via a transmission shaft or the like. It is connected by a device, and the propulsion unit is driven by the engine to travel on water. In such a small boat, the fuel tank is arranged near the engine at the front of the hull, thereby simplifying the fuel supply system to the engine.

However, in the above-mentioned small boat, since the fuel tank is disposed in front of the hull, the fluctuation in the amount of fuel stored in the fuel tank affects the weight balance in the longitudinal direction of the hull, and the fuel There is a disadvantage that the running resistance changes depending on the amount of fuel in the tank.

In view of this, a small boat has been proposed in Japanese Utility Model Laid-Open No. 46-128 or the like, which seems to be able to reduce the influence of running resistance due to a change in the amount of fuel in a fuel tank. This actual opening 46
In the small boat disclosed in -128, a fuel tank is disposed above a power transmission device at a center of the hull in the front-rear direction.

(Problems to be Solved by the Invention) However, in the above-mentioned small boat disclosed in Japanese Utility Model Laid-Open No. 46-128, since the fuel tank is disposed above the power transmission device, the fuel tank is not provided with an upper deck or a seat. In other words, it is difficult to increase the capacity of the fuel tank, and conversely, there is a problem that the freedom of the layout of the seat and the like is restricted.

The present invention has been made in view of the above problems, and can reduce the influence of running resistance due to a change in the amount of fuel in a fuel tank, can increase the capacity of a fuel tank, and can greatly increase the layout of seats and the like. The purpose is to provide a small boat that gives freedom.

(Means for Solving the Problems) In order to solve the above problems, according to the present invention, an engine is mounted on a front part of a hull and a propulsion unit is mounted on a rear part of the hull, and a power transmission device connects the propulsion unit and the engine. And a fuel tank is disposed between the engine and the propulsion unit such that at least a part of the upper surface is located below the power transmission device at the center of the hull, and the fuel tank comprises a hull. Is characterized in that the volume at both sides in the width direction is smaller than the volume at the center.

According to a second aspect, in the first aspect, the fuel tank has a shape in which lower portions on both sides in the width direction of the hull are missing.
On both sides, a support portion for the hull of the fuel tank was formed.

According to a third aspect of the present invention, in the first aspect, the fuel tank is provided with a concave portion that dives downward at a central portion of the hull in the width direction of the hull, and the power transmission device is disposed in the concave portion.

According to a fourth aspect, in the third aspect, the power transmission device has a coupling for connecting a shaft, and the coupling is disposed in front of or behind the fuel tank.

(Operation) In claim 1, since the fuel tank is located at the center of the ship, even if the fuel storage amount in the fuel tank fluctuates,
The influence on the weight balance in the front-rear direction can be reduced, and a change in running resistance due to a change in the amount of fuel stored in the fuel tank can be suppressed. And since the fuel tank is arranged with a part of the upper surface located below the power transmission device, the fuel tank does not restrict the arrangement position of members such as seats,
Great freedom is obtained in the layout of members such as seats, and the capacity of the fuel tank can be increased.

In particular, since the volume of both sides of the fuel tank in the hull width direction is made smaller than the volume of the center portion, the change in weight balance in the hull width direction during rolling can be reduced.

According to the second aspect, in addition to the first aspect, the fuel tank can be supported by the hull on the lower surfaces of both sides where the lower portion of the fuel tank is missing.

According to the third aspect, in addition to the first aspect, a recess is provided at the center of the fuel tank so as to dive downward. By arranging the power transmission in the recess, the layout of the power transmission is free. It is large and can increase the capacity of the fuel tank.

According to a fourth aspect of the present invention, in addition to the third aspect, by disposing the coupling of the power transmission device before and after the concave portion of the fuel tank, the concave portion can be reduced to increase the capacity of the fuel tank. Maintenance becomes easy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 5 show a small boat according to an embodiment of the present invention. FIG. 1 is a plan view, FIG. 2 is a partially broken plan view, and FIG. 3 is a partially broken side view. Fig. 4 is the first
FIG. 5 is a sectional view taken along the line IV-IV of FIG. 5, and FIG. 5 is a sectional view taken along the line VV of FIG.

In FIG. 1, reference numeral 11 denotes a hull configured by joining a hull (lower hull) 12 and a deck (upper hull) 13;
The hull 12 and the deck 13 are made of synthetic resin. deck
A projecting portion 13a is projected upward on the right side of the upper portion 13, and a steering device 14 such as a handle is provided at the rear end of the projecting portion 13a. 14a is a tilt axis of the control device 14.

As shown in FIG. 5, the deck 13 is formed with a concave cabin portion 13b which is opened upward at the rear side. The cabin portion 13b has a seat 15 for a driver and a seat 16 for a passenger.
And are arranged. The seats 15 and 16 are staggered, the driver's seat 15 is located on the right side behind the steering device 14, and the passenger's seat 16 is on the left side.
Located behind. Reference numeral 17 denotes a grip 17 extending back and forth between the seats 15 and 16, and is attached to a protrusion 17a integrally provided on the deck 13. The grip 17 is configured to have a height approximately equal to the waist height of an occupant sitting on the seats 15,16.

In the hull 11, as shown in FIGS. 2 and 3, a power unit 18 is provided at a front portion, a propulsion unit 19 is provided at a rear portion, and a fuel tank 20 is provided at an intermediate portion. These power unit 18, fuel tank 20 and propulsion unit 19
The power supply unit 18 is mounted on a reinforcing member 21 fixed substantially like a ladder, and an opening 24 for maintenance closed by a cover 23 is formed above the power unit 18 in the deck 13.

As shown in FIG. 4, the power unit 18 is integrally assembled with a two-cycle engine 18a and a speed change mechanism 18b, and is mounted on a reinforcing member 21 via mount rubber or the like. The engine 18a is a horizontal engine having a vertical cylinder axis, and extends in the front-rear direction at a position where the crankshaft is deviated to the left of the hull 11. As shown in FIG. 4, a drive gear 99 is fixed to the crankshaft, and the gear 99 is driven by a driven gear 98 of the transmission mechanism 18b.
Meshes with

The speed change mechanism 19b is a parallel gear mechanism in which a main shaft and a sub shaft are arranged substantially horizontally. As is well known, a speed change gear provided on the main shaft and a speed change gear provided on the sub shaft mesh with each other. The countershaft is provided with a driven gear 98 that meshes with a drive gear 99 of the crankshaft and is connected to the crankshaft so that power can be transmitted.The main shaft is located at the center in the width direction of the hull 11 and forms an intermediate shaft 32 that forms a power transmission device. And the propulsion unit 19 via the In FIG. 4, reference numeral 97 denotes a transmission gear provided on the main shaft.

Also, as is well known, the power unit 18 is provided with a fuel pump 22, a carburetor 95, an intake box 96, etc.
A U-shaped exhaust manifold 26 is connected to the exhaust port of each cylinder. The fuel pump 22 has a switching cock 38
The exhaust manifold 26 is connected to a left-side silencer 27 via an exhaust pipe 25. An exhaust pipe 28 is connected to the muffler 27 toward the rear, and the exhaust pipe 28 opens to a concave portion on the bottom of the hull 12 that accommodates the propulsion unit 19. The exhaust of the engine 18a passes through an exhaust pipe 25, a muffler 27, an exhaust pipe 28, etc.
Is discharged into the bottom recess.

The power unit 18 is a two-cycle engine as described above.
It is possible to use not only the engine having the 18a but also the engine having a four-cycle engine as shown in FIG. The engine 18 in FIG.
The cylinder axis is tilted to the left so that the cylinder head is located on the left and the cylinder block is located at the center.

The propulsion unit 19 is a water jet pump type unit as shown in FIG.
An impeller 30 is arranged in 29. The pump housing 29 has a substantially cylindrical shape, with the front end at the bottom and the rear end at the hull 11.
It is open at the back. The impeller 30 is provided on the impeller shaft 31, and the impeller shaft 31 penetrates through the pump housing 29 and is connected to the power unit 18 via the power transmission device 5. 3, the front end side of the impeller shaft 31 is rotatably supported on the hull 12 by a bearing 39. The propulsion unit 19 sucks water from the front end of the pump housing 29 by the rotation of the impeller 30, and this water is
The thrust is generated by jetting backward from the rear end of 29.

The power transmission device 5 connects the front end of the intermediate shaft 32 to the crankshaft of the power unit 18 via the first coupling 33, and connects the rear end of the intermediate shaft 32 to the impeller shaft 31 via the second coupling 34. Consisting of Although not explicitly shown in the figure, the couplings 33 and 34 have an elastic body interposed between the two joint members and transmit power via the elastic body. The intermediate shaft 32 is
As clearly shown in the figure, the fuel tank 20 is disposed in a concave portion 36 formed on the upper surface of the fuel tank 20 at the front and rear, and an intermediate portion is rotatably supported by a bearing 35. The bearing 35 is disposed in a cavity 37 formed vertically in the fuel tank 20 and supported on the hull 12.

As shown in FIG. 5, the fuel tank 20 has a substantially T-shaped cross section in which lower portions on both sides in the width direction are omitted, and both sides in the width direction are mounted on the hull 12 via the support members 42, respectively. Is fixed with a fixing belt 40. Two fuel supply conduits 46 and 47 and an air release conduit 48 are inserted into the fuel tank 20 from the upper surface, and a fuel supply pipe 49 is connected to the left front part. 3 is a bypass pipe for a breather.

One of the fuel supply conduits 46 and 47 is open to the bottom from the other, and is connected to the switching cock 38, respectively. The fuel supply pipe 49 has an upper end opening on the left side of the deck 13 as a fuel supply hole, and a fuel cap 50 is provided in the fuel supply hole. The switching cock 38 has an operation unit disposed beside the operator's seat 15 on the deck 13,
The conduit 45 is shut off (OFF) according to the operation of the operation unit, and the conduits 45 and 46
The fuel tank 20 is located near the center of the hull 11 in the front-rear direction, that is, near the center of gravity of the hull 11, as described above.
The fuel tank 20 is provided with a concave portion 36 extending back and forth on the upper surface, the spatial axis 32 is disposed in the concave portion 36, and a hollow portion 37 penetrating vertically is formed in the fuel tank 20. A bearing 35 is provided in the cavity 37.

In the small boat of this embodiment, the fuel tank 20 is disposed on the hull 11 between the power unit 18 and the propulsion unit 19, that is, at the center in the front-rear direction near the center of gravity of the hull 11. Therefore, the amount of fuel stored in the fuel tank 20 (remaining amount)
Does not affect the front and rear weight balance, and the running resistance can be kept substantially constant.

Further, the fuel tank 20 has a part of the upper surface formed by the power transmission device 5.
, That is, the recess 36 formed in the upper surface
Since the intermediate shaft 32 of the power transmission device 5 is disposed inside the power transmission device 5, the capacity can be increased without causing interference with the power transmission device 5 or the deck 13, and there is great freedom in the layout of the seats 15, 16 attached to the deck 13. can get. And the power transmission device 5
Since the couplings 33 and 34 are located before and after the fuel tank 20, i.e., the couplings 33 and 34 are arranged outside the concave portion 36 of the fuel tank 20, the cross-sectional area of the concave portion 36 can be reduced and the fuel by forming the concave portion 36 The decrease in the capacity of the tank 20 can be reduced, and the space around the couplings 33 and 34 can be increased, thus facilitating maintenance.

Further, the fuel tank 20 is provided on both sides 20a,
The lower part of 20a is missing as described above, the capacity of both sides is smaller than the capacity of the central part, the bottom of both sides 20a, 20a,
It was supported by the reinforcing member 21 described above. For this reason, a change in the weight balance in the width direction due to the movement of the fuel in the fuel tank 20 during rolling or the like can be suppressed.

(Effect of the Invention) As described above, according to the small boat of the present invention, in claim 1, an engine is mounted on the front of the hull, and a propulsion unit is mounted on the rear of the hull, and power is transmitted between the propulsion unit and the engine. In a small boat connected by a device, a fuel tank is disposed between the engine and the propulsion unit with at least a part of the upper surface located below the power transmission device in the center of the hull, and the fuel tank is arranged in the width direction of the hull. The volume on both sides of
Since the volume is made smaller than the volume at the center, it is possible to reduce the influence on the running resistance due to fluctuations in the amount of fuel in the fuel tank, and without affecting the layout of the deck seats or the power transmission device. The capacity of the fuel tank can be increased.

In particular, in the present invention, the volume of both sides of the fuel tank is made smaller than that of the center part, so that the fluctuation of the weight balance during rolling or the like can be suppressed.

According to claim 2, in claim 1, the fuel tank has a shape in which lower portions on both sides in the width direction of the hull are missing, and the both sides constitute a support portion of the fuel tank to the hull. In addition, the fuel tank can be supported on the hull on the lower surface of both sides where the lower part of the fuel tank is missing.

According to a third aspect of the present invention, in the first aspect, the fuel tank is provided with a concave portion that descends downward at a center portion of the hull in the width direction of the hull, and the power transmission device is disposed in the concave portion, so that the fuel tank has a larger capacity. can do.

In claim 4, in claim 3, the power transmission device is:
It has a coupling for connecting the shaft, and this coupling is arranged in front of or behind the combustion tank, so that the recess provided in the fuel tank can be made smaller and the capacity of the fuel tank can be increased, By providing a considerable space around the ring, maintenance of the coupling and the like can be facilitated.

[Brief description of the drawings]

1 to 5 show a small boat according to an embodiment of the present invention. FIG. 1 is a plan view, FIG. 2 is a partially broken plan view, and FIG. 3 is a partially broken side view. FIG. 4 is a sectional view taken along the line IV-IV of FIG. 1, and FIG. 5 is a sectional view taken along the line VV of FIG. FIG. 6 is a sectional view similar to FIG. 4, showing another embodiment of the present invention. 5 ... power transmission device, 11 ... hull, 13 ... deck, 18 ...
... power unit, 18a ... engine, 19 ... propulsion unit, 20 ... fuel tank, 32 ... intermediate shaft, 33, 34 ... coupling, 35 ... bearing, 36 ... recess, 37 ... cavity.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B63H 21/38 B63B 35/73

Claims (4)

(57) [Claims] 1. A small boat in which an engine is mounted at a front part of a hull and a propulsion unit is mounted at a rear part of the hull, and the propulsion unit and the engine are connected by a power transmission device. At least a part of the upper surface is located below the power transmission device at the center, and a fuel tank is disposed.The fuel tank has a smaller volume at both sides in the width direction of the hull than at the center. A small boat characterized by the above. 2. The fuel tank according to claim 1, wherein the fuel tank has a shape in which lower portions on both sides in the width direction of the hull are missing, and the both sides constitute a support for the combustion tank on the hull. Small ship. 3. The small-sized fuel tank according to claim 1, wherein the fuel tank has an upper surface provided with a concave portion which is sunk downward at a central portion in a width direction of the hull, and the power transmission device is disposed in the concave portion. Ship. 4. The power transmission device according to claim 3, wherein the power transmission device has a coupling for connecting the shaft, and the coupling is disposed in front of or behind the fuel tank.
A small vessel as described.